Soil management shapes ecosystem service provision and trade-offs in agricultural landscapes.

PubMed

Tamburini, Giovanni; De Simone, Serena; Sigura, Maurizia; Boscutti, Francesco; Marini, Lorenzo

2016-08-31

Agroecosystems are principally managed to maximize food provisioning even if they receive a large array of supporting and regulating ecosystem services (ESs). Hence, comprehensive studies investigating the effects of local management and landscape composition on the provision of and trade-offs between multiple ESs are urgently needed. We explored the effects of conservation tillage, nitrogen fertilization and landscape composition on six ESs (crop production, disease control, soil fertility, water quality regulation, weed and pest control) in winter cereals. Conservation tillage enhanced soil fertility and pest control, decreased water quality regulation and weed control, without affecting crop production and disease control. Fertilization only influenced crop production by increasing grain yield. Landscape intensification reduced the provision of disease and pest control. We also found tillage and landscape composition to interactively affect water quality regulation and weed control. Under N fertilization, conventional tillage resulted in more trade-offs between ESs than conservation tillage. Our results demonstrate that soil management and landscape composition affect the provision of several ESs and that soil management potentially shapes the trade-offs between them. © 2016 The Author(s).

Effects of Vegetation Management With Prescribed Fire on Soil Physical Properties in a Young Longleaf Pine Stand

Treesearch

W.B. Patterson; M.A. Sword-Sayer; J.D. Haywood; S. Brooker

2004-01-01

The intensity and frequency of prescribed fire affects soil properties that control its quality. This project evaluates how six vegetation management treatments, four of which include biennial prescribed fire, affect the soil physical properties in two stands of longleaf pine (Pinus palustris Mill.) located on the Kisatchie National Forest, Rapides...

Sugarcane straw harvest effects on soil quality and plant growth: preliminary data synthesis of a multi-local project running in Brazil

NASA Astrophysics Data System (ADS)

Cherubin, Maurício; Cerri, Carlos E. P.; Feigl, Brigitte J.; Cerri, Carlos C.

2017-04-01

Brazil is the largest sugarcane producer in the world, and consequently, it is one of major players in the bioenergy production sector. Despite that, growing demands for bioenergies have raised the interest of Brazilian sugarcane industry to harvest the sugarcane straw left on the field for cellulosic ethanol production and/or bioelectricity cogeneration. However, crop residues have a key role in the soil, affecting directly or indirectly multiple soil functions and related ecosystem services. Therefore, indiscriminate straw harvest could jeopardize soil quality, decreasing its capacity to sustain plant productivity over time. In order to evaluate the potential impacts of sugarcane straw harvest on soil quality and plant growth, we are conducting since 2014 a multi-local project across central-southern Brazil, the main core of sugarcane production in the world. A wide range of soil chemical, physical and biological parameters, as well as, plant biomass production has been quantified under increasing straw harvest intensities. Our preliminary findings have showed that short-term straw harvest management did not affect total organic C stocks; however, high straw harvest led to significant reduction in labile C forms (e.g., microbial biomass C and N), and abundance of microbial communities as well. Sugarcane straw harvest affects soil nutrient cycling, since significant amount of nutrients are removed annually by straw, especially in top (green) leaves. In addition, our data show that straw acts as a thermal insulator, decreasing soil temperature amplitude and keeping soil moisture for a longer time. Straw harvest management did not affect sugarcane yields in the first two crop seasons. Based on this first synthesis of the project, we conclude that short-term sugarcane straw harvest led to soil changes, especially in more sensitive and dynamic properties, which did not affect the plant yield. However, long-term impacts should be monitored towards a better understanding about potential trade-offs and synergies associated with sugarcane straw harvest for bioenergy production in Brazil.

Soils and public health: the vital nexus

USDA-ARS?s Scientific Manuscript database

Soils sustain life. They affect human health via quantity, quality, and safety of available food and water, and via direct exposure of individuals to soils. Throughout the history of civilization, soil-health relationships have inspired spiritual movements, philosophical systems, cultural exchanges,...

Predicting plot soil loss by empirical and process-oriented approaches: A review

USDA-ARS?s Scientific Manuscript database

Soil erosion directly affects the quality of the soil, its agricultural productivity and its biological diversity. Many mathematical models have been developed to estimate plot soil erosion at different temporal scales. At present, empirical soil loss equations and process-oriented models are consid...

Impacts of soil moisture content on visual soil evaluation

NASA Astrophysics Data System (ADS)

Emmet-Booth, Jeremy; Forristal, Dermot; Fenton, Owen; Bondi, Giulia; Creamer, Rachel; Holden, Nick

2017-04-01

Visual Soil Examination and Evaluation (VSE) techniques offer tools for soil quality assessment. They involve the visual and tactile assessment of soil properties such as aggregate size and shape, porosity, redox morphology, soil colour and smell. An increasing body of research has demonstrated the reliability and utility of VSE techniques. However a number of limitations have been identified, including the potential impact of soil moisture variation during sampling. As part of a national survey of grassland soil quality in Ireland, an evaluation of the impact of soil moisture on two widely used VSE techniques was conducted. The techniques were Visual Evaluation of Soil Structure (VESS) (Guimarães et al., 2011) and Visual Soil Assessment (VSA) (Shepherd, 2009). Both generate summarising numeric scores that indicate soil structural quality, though employ different scoring mechanisms. The former requires the assessment of properties concurrently and the latter separately. Both methods were deployed on 20 sites across Ireland representing a range of soils. Additional samples were taken for soil volumetric water (θ) determination at 5-10 and 10-20 cm depth. No significant correlation was observed between θ 5-10 cm and either VSE technique. However, VESS scores were significantly related to θ 10-20 cm (rs = 0.40, sig = 0.02) while VSA scores were not (rs = -0.33, sig = 0.06). VESS and VSA scores can be grouped into quality classifications (good, moderate and poor). No significant mean difference was observed between θ 5-10 cm or θ 10-20 cm according to quality classification by either method. It was concluded that VESS scores may be affected by soil moisture variation while VSA appear unaffected. The different scoring mechanisms, where the separate assessment and scoring of individual properties employed by VSA, may limit soil moisture effects. However, moisture content appears not to affect overall structural quality classification by either method. References Guimarães, R.M.C., Ball, B.C. & Tormena, C.A. 2011. Improvements in the visual evaluation of soil structure, Soil Use and Management, 27, 3: 395-403 Shepherd, G.T. 2009. Visual Soil Assessment. Field guide for pastoral grazing and cropping on flat to rolling country. 2nd edn. Horizons regional council, New Zealand.

[Effects of soil, climate, and their interaction on some neutral volatile aroma components in flue-cured tobacco leaves from high quality tobacco planting regions of Hunan Province].

PubMed

Deng, Xiao-Hua; Xie, Peng-Fei; Peng, Xin-Hui; Yi, Jian-Hua; Zhou, Ji-Heng; Zhou, Qing-Ming; Pu, Wen-Xuan; Dai, Yuan-Gang

2010-08-01

A pot experiment with the soils from Yongzhou, Liuyang, and Sangzhi, the high-quality tobacco planting regions of Hunan Province, was conducted to study the effects of climate, soil, and their interaction on some neutral volatile aroma components in flue-cured tobacco leaves. The contents of test neutral volatile aroma components in the flue-cured tobacco leaves were of medium variation, and the variation intensity was decreased in the order of dihydroactinolide, damascenone, furfural, total megastigmatrienone, and beta-ionone. Climate, soil, and their interaction affected the neutral volatile aroma components in different degrees. The furfural content was most affected by climate, the damascenone content was most affected by climate and by soil, the total megastigmatrienone and beta-ionone contents were most affected by the interaction of soil and climate, while the dihydroactinolide content was less affected by soil, climate, and their interaction. The contribution of climate, soil, and their interaction to the contents of the five aroma components was 40.82%, 20.67%, and 38.51%, respectively. During different growth periods of tobacco, different climate factors had different effects on the neutral volatile aroma components. The rainfall, cloudiness, and mean air temperature at rooting stage, the diurnal temperature amplitude, sunshine time, and evaporation at vigorous growth stage, and the rainfall, evaporation, and mean air temperature at maturing stage were the top three climate factors affecting the contents of the neutral volatile aroma components in flue-tobacco leaves. For the soil factors, the available potassium, available phosphorus, and pH were the top three factors affecting the contents of the five components.

Sample storage-induced changes in the quantity and quality of soil labile organic carbon

PubMed Central

Sun, Shou-Qin; Cai, Hui-Ying; Chang, Scott X.; Bhatti, Jagtar S.

2015-01-01

Effects of sample storage methods on the quantity and quality of labile soil organic carbon are not fully understood even though their effects on basic soil properties have been extensively studied. We studied the effects of air-drying and frozen storage on cold and hot water soluble organic carbon (WSOC). Cold- and hot-WSOC in air-dried and frozen-stored soils were linearly correlated with those in fresh soils, indicating that storage proportionally altered the extractability of soil organic carbon. Air-drying but not frozen storage increased the concentrations of cold-WSOC and carbohydrate in cold-WSOC, while both increased polyphenol concentrations. In contrast, only polyphenol concentration in hot-WSOC was increased by air-drying and frozen storage, suggesting that hot-WSOC was less affected by sample storage. The biodegradability of cold- but not hot-WSOC was increased by air-drying, while both air-drying and frozen storage increased humification index and changed specific UV absorbance of both cold- and hot-WSOC, indicating shifts in the quality of soil WSOC. Our results suggest that storage methods affect the quantity and quality of WSOC but not comparisons between samples, frozen storage is better than air-drying if samples have to be stored, and storage should be avoided whenever possible when studying the quantity and quality of both cold- and hot-WSOC. PMID:26617054

Microbiological indicators for assessing ecosystem soil quality and changes in it at degraded sites treated with compost

NASA Astrophysics Data System (ADS)

Ancona, Valeria; Barra Caracciolo, Anna; Grenni, Paola; Di Lenola, Martina; Calabrese, Angelantonio; Campanale, Claudia; Felice Uricchio, Vito

2014-05-01

Soil quality is defined as the capacity of a soil to function as a vital system, within natural or managed ecosystem boundaries, sustain plant and animal health and productivity, maintain or enhance air and water environment quality and support human health and habitation. Soil organisms are extremely diverse and contribute to a wide range of ecosystem services that are essential to the sustainable functioning of natural and managed ecosystems. In particular, microbial communities provide several ecosystem services, which ensure soil quality and fertility. In fact, they adapt promptly to environmental changes by varying their activity and by increasing the reproduction of populations that have favourable skills. The structure (e.g. cell abundance) and functioning (e.g. viability and activity) of natural microbial communities and changes in them under different environmental conditions can be considered useful indicators of soil quality state. In this work we studied the quality state of three different soils, located in Taranto Province (Southern Italy), affected by land degradation processes, such as organic matter depletion, desertification and contamination (PCB and metals). Moreover, compost, produced from selected organic waste, was added to the soils studied in order to improve their quality state. Soil samples were collected before and after compost addition and both microbial and chemical analyses were performed in order to evaluate the soil quality state at each site at different times. For this purpose, the microbiological indicators evaluated were bacterial abundance (DAPI counts), cell viability (Live/Dead method), dehydrogenase activity (DHA) and soil respiration. At the same time, the main physico-chemical soil characteristics (organic carbon, available phosphorous, total nitrogen, carbonate and water content, texture and pH) were also measured. Moreover, in the contaminated soil samples PCB and inorganic (e.g. Pb, Se, Sn, Zn) contaminants were analysed respectively by GC-MS and ICP-MS. The overall results showed that the bacterial structure and functioning were affected in different ways by the organic carbon availability and quality, and contaminant occurrence (organic or inorganic compounds). The compost treatment contributed to improve soil fertility and to increase cell number and activity after 7 months in the two low organic carbon content soils. At the polluted site a general increase in bacterial activity after compost addition was also observed and this might be related to a decrease in inorganic and organic contamination levels.

Simultaneous determination of multiple soil enzyme activities for soil health-biogeochemical indexes

USDA-ARS?s Scientific Manuscript database

Enzyme activities (EAs) are soil health indicators of changes in decomposition processes due to management and the crop(s) affecting the quantity and quality of plant residues and nutrients entering the soil. More commonly assessed soil EAs can provide information of reactions where plant available ...

Soil biodiversity and human health

NASA Astrophysics Data System (ADS)

Six, Johan; Pereg, Lily; Brevik, Eric

2017-04-01

Biodiversity is important for the maintenance of soil quality. Healthy, biodiverse soils are crucial for human health and wellbeing from several reasons, for example: biodiversity has been shown to be important in controlling populations of pathogens; healthy, well-covered soils can reduce disease outbreaks; carbon-rich soils may also reduce outbreaks of human and animal parasites; exposure to soil microbes can reduce allergies; soils have provided many of our current antibiotics; soil organisms can provide biological disease and pest control agents, healthy soils mean healthier and more abundant foods; soil microbes can enhance crop plant resilience; healthy soils promote good clean air quality, less prone to wind and water erosion; and healthy soils provide clean and safe water through filtration, decontamination by microbes and removal of pollutants. Soil microbes and other biota provide many benefits to human health. Soil microbes are a source of medicines, such as antibiotics, anticancer drugs and many more. Organisms that affect soil health and thus human health include those involved in nutrient cycling, decomposition of organic matter and determining soil structure (e.g. aggregation). Again these are related to food security but also affect human health in other ways. Many beneficial organisms have been isolated from soil - plant growth promoting and disease suppressive microbes used as inoculants, foliar inoculants for improvement of ruminant digestion systems and inoculants used in bioremediation of toxic compounds in the environment. Soil biodiversity is highly recognised now as an important feature of healthy soil and imbalances have been shown to give advantage to harmful over beneficial organisms. This presentation will highlight the many connections of biodiversity to soil quality and human health.

Elevation, rootstock, and soil depth affect the nutritional quality of mandarin oranges

USDA-ARS?s Scientific Manuscript database

The effects of elevation, rootstock, and soil depth on the nutritional quality of mandarin oranges from 11 groves in California were investigated by nuclear magnetic resonance (NMR) spectroscopy by quantifying 29 compounds and applying multivariate statistical data analysis. A comparison of the juic...

Assessing the use of treated waste water for irrigation agricultural lands by using soil quality indices

NASA Astrophysics Data System (ADS)

Arcenegui, V.; Morugán, A.; García-Orenes, F.; Zornoza, R.; Mataix-Solera, J.; Navarro, M. A.; Guerrero, C.; Mataix-Beneyto, J.

2009-04-01

The use of treated wastewater for the irrigation of agricultural soils is an alternative to utilizing better-quality water, especially in semiarid regions where water shortage is a very serious problem. However, this practise can modify the soil equilibrium and affect its quality. In this work two soil quality indices (models) are used to evaluate the effects of long-term irrigation with treated wastewater in soil. The models were developed studying different soil properties in undisturbed forest soils in SE Spain, and the relationships between soil parameters were established using multiple linear regressions. Model 1, that explained 92% of the variance in soil organic carbon (SOC) showed that the SOC can be calculated by the linear combination of 6 physical, chemical and biochemical properties (acid phosphatase, water holding capacity (WHC), electrical conductivity (EC), available phosphorus (P), cation exchange capacity (CEC) and aggregate stability (AS)). Model 2 explains 89% of the SOC variance, which can be calculated by means of 7 chemical and biochemical properties (urease, phosphatase, and

An approach to determine multiple enzyme activities in the same soil sample for soil health-biogeochemical indexes

USDA-ARS?s Scientific Manuscript database

Enzyme activities (EAs) are soil health indicators of changes in decomposition processes due to management and the crop(s) affecting the quantity and quality of plant residues and nutrients entering the soil. More commonly assessed soil EAs can provide information of reactions where plant available ...

Microbial community structure is affected by cropping sequences and poultry litter under long-term no-tillage

USDA-ARS?s Scientific Manuscript database

Soil microorganisms play essential roles in soil organic matter dynamics and nutrient cycling in agroecosystems and have been used as soil quality indicators. The response of soil microbial communities to land management is complex and the long-term impacts of cropping systems on soil microbes is l...

Environmental risk of heavy metal pollution and contamination sources using multivariate analysis in the soils of Varanasi environs, India.

PubMed

Singh, Shubhra; Raju, N Janardhana; Nazneen, Sadaf

2015-06-01

This study assessed soil pollution in the Varanasi environs of Uttar Pradesh in India. Assessing the concentration of potentially harmful heavy metals in the soils is imperative in order to evaluate the potential risks to human. To identify the concentration and sources of heavy metals and assess the soil environmental quality, 23 samples were collected from different locations covering dumping, road and agricultural area. The average concentrations of the heavy metals were all below the permissible limits according to soil quality guidelines except Cu (copper) and Pb (lead) in dumping and road soils. Soil heavy metal contamination was assessed on the basis of geoaccumulation index (Igeo), pollution index (PI) and integrated pollution index (IPI). The IPI of the metals ranged from 0.59 to 9.94, with the highest IPI observed in the dumping and road soils. A very significant correlation was found between Pb and Cu. The result of principal component analysis suggested that PC1 was mainly affected by the use of agrochemicals, PC2 was affected by vehicular emission and PC3 was affected by dumping waste. Meanwhile, PC4 was mainly controlled by parent material along with anthropogenic activities. Appropriate measures should be taken to minimize the heavy metal levels in soils and thus protect human health.

O3, CO2 and chemical fractionation in ponderosa pine saplings

EPA Science Inventory

Environmental factors can affect plant tissue quality which is important for quality of organic matter inputs into soil food webs and decomposition of soil organic matter. Thus the effects of increases in CO2 and O3 and their interactions were determined for various chemical fra...

Fluorescence spectroscopic analysis of organic matter fractions: the current status and a tutorial case study

USDA-ARS?s Scientific Manuscript database

Incorporation of animal manures into soils is a key nutrient management strategy for sustainable agricultural systems by supplying plant nutrients and maintaining soil quality. Dissolved organic matter (DOM) released from manures affects many soil chemical processes due to its reactivity with soil ...

Changes in soil bacterial community triggered by drought-induced gap succession preceded changes in soil C stocks and quality

PubMed Central

Yuste, Jorge Curiel; Barba, Josep; Fernandez-Gonzalez, Antonio José; Fernandez-Lopez, Manuel; Mattana, Stefania; Martinez-Vilalta, Jordi; Nolis, Pau; Lloret, Francisco

2012-01-01

The aim of this study was to understand how drought-induced tree mortality and subsequent secondary succession would affect soil bacterial taxonomic composition as well as soil organic matter (SOM) quantity and quality in a mixed Mediterranean forest where the Scots pine (Pinus sylvestris) population, affected by climatic drought-induced die-off, is being replaced by Holm-oaks (HO; Quercus ilex). We apply a high throughput DNA pyrosequencing technique and 13C solid-state Nuclear Magnetic Resonance (CP-MAS 13C NMR) to soils within areas of influence (defined as an surface with 2-m radius around the trunk) of different trees: healthy and affected (defoliated) pines, pines that died a decade ago and healthy HOs. Soil respiration was also measured in the same spots during a spring campaign using a static close-chamber method (soda lime). A decade after death, and before aerial colonization by the more competitive HOs have even taken place, we could not find changes in soil C pools (quantity and/or quality) associated with tree mortality and secondary succession. Unlike C pools, bacterial diversity and community structure were strongly determined by tree mortality. Convergence between the most abundant taxa of soil bacterial communities under dead pines and colonizer trees (HOs) further suggests that physical gap colonization was occurring below-ground before above-ground colonization was taken place. Significantly higher soil respiration rates under dead trees, together with higher bacterial diversity and anomalously high representation of bacteria commonly associated with copiotrophic environments (r-strategic bacteria) further gives indications of how drought-induced tree mortality and secondary succession were influencing the structure of microbial communities and the metabolic activity of soils. PMID:23301169

Assessment of soil quality index for wheat and sugar beet cropping systems on an entisol in Central Anatolia.

PubMed

Şeker, Cevdet; Özaytekin, Hasan Hüseyin; Negiş, Hamza; Gümüş, İlknur; Dedeoğlu, Mert; Atmaca, Emel; Karaca, Ümmühan

2017-04-01

The sustainable use of agricultural lands is significantly affected by the implemented management and land processing methods. In sugar beet and wheat cropping, because the agronomic characteristics of plants are different, the tillage methods applied also exhibit significant variability. Soil quality concept is used, as a holistic approach to determining the effects of these applications on the sustainable use of soil. Agricultural soil quality evaluation is essential for economic success and environmental stability in rapidly developing regions. At present, a variety of methods are used to evaluate soil quality using different indicators. This study was conducted in one of the most important irrigated agriculture areas of Çumra plain in Central Anatolia, Turkey. In the soil under sugar beet and wheat cultivation, 12 soil quality indicators (aggregate stability (AS), available water capacity (AWC), surface penetration resistance (PR 0-20 ), subsurface penetration resistance (PR 20-40 ), organic matter (OM), active carbon (AC), potentially mineralizable nitrogen (PMN), root health value (RHV), pH, available phosphorus (AP), potassium (K), and macro-micro elements (ME) (Mg, Fe, Mn, and Zn)) were measured and scored according to the Cornell Soil Health Assessment (CSHA) and the Soil Management Assessment Framework (SMAF). The differences among 8 (AS, AWC, PR 0-20 , PR 20-40 , AC, PMN, AP, and ME) of these 12 soil quality characteristics measured in two different plant cultivation were found statistically significant. The result of the soil quality evaluation with scoring function in the examined area revealed a soil quality score of 61.46 in the wheat area and of 51.20 in the sugar beet area, which can be classified as medium and low, respectively. Low soil quality scores especially depend on physical and biological soil properties. Therefore, improvement of soil physical and biological properties with sustainable management is necessary to enhance the soil quality in the study area soils.

RELATIONSHIPS BETWEEN CULTURABLE SOIL MICROBIAL POPULATIONS AND GROSS NITROGEN TRANSFORMATION PROCESSES IN A CLAY LOAM SOIL ACROSS ECOSYSTEMS

EPA Science Inventory

The size and quality of soil organic matter (SOM) pool can vary between ecosystems and can affect many soil properties. The objective of this study was to examine the relationship between gross N transformation rates and microbial populations and to investigate the role that SOM...

Changes in soil nutrients after 10 years of cattle manure and swine effluent application

USDA-ARS?s Scientific Manuscript database

Application of cattle manure and swine effluent to cropland builds nutrient pools, affects soil quality, and increases crop productivity. The objective of the present study was to evaluate the rate of change in soil nutrient concentration and soil chemical properties due to cattle manure and swine e...

Moisture controls decomposition rate in thawing tundra

Treesearch

C.E. Hicks-Pries; E.A.G. Schuur; S.M. Natali; J.G. Vogel

2013-01-01

Permafrost thaw can affect decomposition rates by changing environmental conditions and litter quality. As permafrost thaws, soils warm and thermokarst (ground subsidence) features form, causing some areas to become wetter while other areas become drier. We used a common substrate to measure how permafrost thaw affects decomposition rates in the surface soil in a...

Fertilizer nitrogen, soil chemical properties, and their determinacy on rice yield: Evidence from 92 paddy fields of a large-scale farm in the Kanto Region of Japan

NASA Astrophysics Data System (ADS)

Li, D.; Nanseki, T.; Chomei, Y.; Yokota, S.

2017-07-01

Rice, a staple crop in Japan, is at risk of decreasing production and its yield highly depends on soil fertility. This study aimed to investigate determinants of rice yield, from the perspectives of fertilizer nitrogen and soil chemical properties. The data were sampled in 2014 and 2015 from 92 peat soil paddy fields on a large-scale farm located in the Kanto Region of Japan. The rice variety used was the most widely planted Koshihikari in Japan. Regression analysis indicated that fertilizer nitrogen significantly affected the yield, with a significant sustained effect to the subsequent year. Twelve soil chemical properties, including pH, cation exchange capacity, content of pyridine base elements, phosphoric acid, and silicic acid, were estimated. In addition to silicic acid, magnesia, in forms of its exchangeable content, saturation, and ratios to potassium and lime, positively affected the yield, while phosphoric acid negatively affected the yield. We assessed the soil chemical properties by soil quality index and principal component analysis. Positive effects were identified for both approaches, with the former performing better in explaining the rice yield. For soil quality index, the individual standardized soil properties and margins for improvement were indicated for each paddy field. Finally, multivariate regression on the principal components identified the most significant properties.

SOM quality and phosphorus fractionation to evaluate degradation organic matter: implications for the restoration of soils after fire

NASA Astrophysics Data System (ADS)

Merino, Agustin; Fonturbel, Maria T.; Omil, Beatriz; Chávez-Vergara, Bruno; Fernandez, Cristina; Garcia-Oliva, Felipe; Vega, Jose A.

2016-04-01

The design of emergency treatment for the rehabilitation of fire-affected soils requires a quick diagnosis to assess the degree of degradation. For its implication in the erosion and subsequent evolution, the quality of soil organic matter (OM) plays a particularly important role. This paper presents a methodology that combines the visual recognition of the severity of soil burning with the use of simple analytical techniques to assess the degree of degradation of OM. The content and quality of the OM was evaluated in litter and mineral soils using thermogravimetry-differential scanning calorimetry (DSC-TG) spectroscopy, and the results were contrasted with 13C CP-MAS NMR. The types of methodologies were texted to assess the thermal analysis: a) the direct calculation of the Q areas related to three degrees of thermal stabilities: Q1 (200-375 °C; labil OM); Q2 (375-475 °C, recalcitrant OM); and Q3 (475-550 °C). b) deconvolution of DSC curves and calculation of each peak was expressed as a fraction of the total DSC curve area. Additionally, a P fractionation was done following the Hedley sequential extraction method. The severity levels visually showed different degrees of SOM degradation. Although the fire caused important SOM losses in moderate severities, changes in the quality of OM only occurred at higher severities. Besides, the labile organic P fraction decreased and the occluded inorganic P fraction increased in the high severity soils. These changes affect the OM processes such as hydrophobicity and erosion largely responsible for soil degradation post-fire. The strong correlations between the thermal parameters and NMR regions and derived measurements such as hydrophobicity and aromaticity show the usefulness of this technique as rapid diagnosis to assess the soil degradation.The marked loss of polysaccharide and transition to highly thermic-resistant compounds, visible in deconvoluted thermograms, which would explain the changes in microbial activity and soil nutrients availability (basal respiration, microbial biomass, qCO2, and enzymatic activity). And also it would have implications in hydrophobicity and stability of soil aggregates, leading to the extreme erosion rates that occur usually are found in soils affected by higher severities.

Management practices affect soil nutrients and bacterial populations in backgrounding beef feedlot

USDA-ARS?s Scientific Manuscript database

Contaminants associated with manure in animal production sites are of significant concern. Unless properly managed, high soil nutrient concentrations in feedlots can deteriorate soil and water quality. This three year study tested a nutrient management strategy with three sequentially imposed manage...

Amending greenroof soil with biochar to affect runoff water quantity and quality.

PubMed

Beck, Deborah A; Johnson, Gwynn R; Spolek, Graig A

2011-01-01

Numbers of greenroofs in urban areas continue to grow internationally; so designing greenroof soil to reduce the amount of nutrients in the stormwater runoff from these roofs is becoming essential. This study evaluated changes in extensive greenroof water discharge quality and quantity after adding biochar, a soil amendment promoted for its ability to retain nutrients in soils and increase soil fertility. Prototype greenroof trays with and without biochar were planted with sedum or ryegrass, with barren soil trays used as controls. The greenroof trays were subjected to two sequential 7.4cm/h rainfall events using a rain simulator. Runoff from the rain events was collected and evaluated. Trays containing 7% biochar showed increased water retention and significant decreases in discharge of total nitrogen, total phosphorus, nitrate, phosphate, and organic carbon. The addition of biochar to greenroof soil improves both runoff water quality and retention. Copyright © 2011 Elsevier Ltd. All rights reserved.

Assessment of the levels of potentially toxic substances around a transect of anthrosols in Aqaba shoreline, Jordan

NASA Astrophysics Data System (ADS)

Wahsha, Mohammad; Al-Rousan, Saber; Al-Jawasreh, Raid

2016-04-01

Soils are the major sink for potentially toxic substances (PTSs) such as heavy metals released into the environment by emissions from the quickly increasing of human impact including industrial mine tailings, disposal of high metal wastes, land misuse, wastewater irrigation, spillage of petrochemicals, and atmospheric deposition. The present study concerns the properties variability and soil biological health status in abandoned salt transportation port site in the Jordanian coast of the Gulf of Aqaba, Red Sea. Seven sites were selected according to different morphological and pedological conditions, anthropogenic impact and the same climate conditions. Successively, all locations were sampled for topsoil in the period between spring-summer 2014. Field observations as well as laboratory analysis including heavy metal concentrations (Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn); soil chemo-physical parameters (pH, soil dry mass, carbonate, water holding, organic carbon content, soil particle size distribution), and quality of soil's biological community were determined. The anthropogenic influence related to former port activity on soils of the studied area is evident. Soils in the studied area site are highly contaminated by PTSs, mainly Cu and Zn, by 648, 298.6 mgKg-1respectively. Former activities proved to affect the microarthropods community altering both quantity and quality of soil and the chemo-physical structure of the microhabitats. The evaluation of soil biological quality index (QBS-ar) of the surface horizons from the study area is demonstrated that the area is "sufferings" since it is affected by PTSs contamination resulting in a failure in the ecological success of secondary recolonization after abandonment. However, there is an increasing need for further research in the soils of Aqaba focusing on soil health management , combining QBS-ar index with soil chemo-physical properties. Key words: Potentially Toxic Substances, Heavy Metals, Soil Quality.

The relationships between microbiological attributes and soil and litter quality in pure and mixed stands of native tree species in southeastern Bahia, Brazil.

PubMed

Gama-Rodrigues, Emanuela F; Gama-Rodrigues, Antonio Carlos; Barros, Nairam F; Moço, Maria Kellen S

2011-11-01

This study was conducted to link soil and litter microbial biomass and activity with soil and litter quality in the surface layer for different pure and mixed stands of native tree species in southeastern Bahia, Brazil. The purpose of the study was to see how strongly the differences among species and stands affect the microbiological attributes of the soil and to identify how microbial processes can be influenced by soil and litter quality. Soil and litter samples were collected from six pure and mixed stands of six hardwood species (Peltogyne angustifolia, Centrolobium robustum, Arapatiella psilophylla, Sclerolobium chrysophyllum, Cordia trichotoma, Macrolobium latifolium) native to the southeastern region of Bahia, Brazil. In plantations of native tree species in humid tropical regions, the immobilization efficiency of C and N by soil microbial biomass was strongly related to the chemical quality of the litter and to the organic matter quality of the soil. According to the variables analyzed, the mixed stand was similar to the natural forest and dissimilar to the pure stands. Litter microbial biomass represented a greater sink of C and N than soil microbial biomass and is an important contributor of resources to tropical soils having low C and N availability.

77 FR 34093 - License Renewal for Calvert Cliffs Nuclear Power Plant, LLC's

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-08

... quality; water quality and use; geology and soils; ecology; noise; historical and cultural; scenic and... significantly affect the quality of the human environment. Therefore, preparation of an environmental impact...

Zeolite Soil Application Method Affects Inorganic Nitrogen, Moisture, and Corn Growth

USDA-ARS?s Scientific Manuscript database

Adoption of new management techniques which improve soil water storage and soil nitrogen plant availability yet limit nitrogen leaching may help improve environmental quality. A benchtop study was conducted to determine the influence of a single urea fertilizer rate (224 kilograms of Nitrogen per ...

Hydrologic and water quality effects of thinning Loblolly Pine

Treesearch

Johnny M. Grace; R. W. Skaggs; G. M. Chescheir

2006-01-01

Forest operations such as harvesting, thinning, and site preparation can affect the hydrologic behavior of watersheds on poorly drained soils. The influence of these operations conducted on organic soil sites can be more pronounced than on mineral soil sites due to the differences in bulk density and soil moisture relationships that exist between mineral and organic...

Activities of five enzymes following soil disturbance and weed control in a Missouri forest

Treesearch

Felix, Jr. Ponder; Frieda Eivazi

2008-01-01

Forest disturbances associated with harvesting activities can affect soil properties including enzyme activity and overall soil quality. The activities of five enzymes (acid and alkaline phosphatases, betaglucosidase, aryl-sulfatase, and beta-glucosominidase) were measured after 8 years in soil from clearcut and uncut control plots of a Missouri oak-hickory (...

Estimating carbon in forest soils of the United States using the national forest inventory

Treesearch

Grant M. Domke; Charles H. (Hobie) Perry; Brian F. Walters; Christopher W. Woodall; Lucas E. Nave; Chris Swanston

2015-01-01

Soil organic carbon (SOC) is the largest terrestrial carbon (C) sink on earth and management of this pool is a critical component of global efforts to mitigate atmospheric C concentrations. Soil organic carbon is also a key indicator of soil quality as it affects essential biological, chemical, and physical soil functions such as nutrient cycling, water retention, and...

Spatial variation in soil properties and diffuse losses between and within grassland fields with similar short-term management.

PubMed

Peukert, S; Griffith, B A; Murray, P J; Macleod, C J A; Brazier, R E

2016-07-01

One of the major challenges for agriculture is to understand the effects of agricultural practices on soil properties and diffuse pollution, to support practical farm-scale land management. Three conventionally managed grassland fields with similar short-term management, but different ploughing histories, were studied on a long-term research platform: the North Wyke Farm Platform. The aims were to (i) quantify the between-field and within-field spatial variation in soil properties by geostatistical analysis, (ii) understand the effects of soil condition (in terms of nitrogen, phosphorus and carbon contents) on the quality of discharge water and (iii) establish robust baseline data before the implementation of various grassland management scenarios. Although the fields sampled had experienced the same land use and similar management for at least 6 years, there were differences in their mean soil properties. They showed different patterns of soil spatial variation and different rates of diffuse nutrient losses to water. The oldest permanent pasture field had the largest soil macronutrient concentrations and the greatest diffuse nutrient losses. We show that management histories affect soil properties and diffuse losses. Potential gains in herbage yield or benefits in water quality might be achieved by characterizing every field or by area-specific management within fields (a form of precision agriculture for grasslands). Permanent pasture per se cannot be considered a mitigation measure for diffuse pollution. The between- and within-field soil spatial variation emphasizes the importance of baseline characterization and will enable the reliable identification of any effects of future management change on the Farm Platform. Quantification of soil and water quality in grassland fields with contrasting management histories.Considerable spatial variation in soil properties and diffuse losses between and within fields.Contrasting management histories within and between fields strongly affected soil and water quality.Careful pasture management needed: the oldest pasture transferred the most nutrients from soil to water.

Litter quality versus soil microbial community controls over decomposition: a quantitative analysis

USGS Publications Warehouse

Cleveland, Cory C.; Reed, Sasha C.; Keller, Adrienne B.; Nemergut, Diana R.; O'Neill, Sean P.; Ostertag, Rebecca; Vitousek, Peter M.

2014-01-01

The possible effects of soil microbial community structure on organic matter decomposition rates have been widely acknowledged, but are poorly understood. Understanding these relationships is complicated by the fact that microbial community structure and function are likely to both affect and be affected by organic matter quality and chemistry, thus it is difficult to draw mechanistic conclusions from field studies. We conducted a reciprocal soil inoculum × litter transplant laboratory incubation experiment using samples collected from a set of sites that have similar climate and plant species composition but vary significantly in bacterial community structure and litter quality. The results showed that litter quality explained the majority of variation in decomposition rates under controlled laboratory conditions: over the course of the 162-day incubation, litter quality explained nearly two-thirds (64 %) of variation in decomposition rates, and a smaller proportion (25 %) was explained by variation in the inoculum type. In addition, the relative importance of inoculum type on soil respiration increased over the course of the experiment, and was significantly higher in microcosms with lower litter quality relative to those with higher quality litter. We also used molecular phylogenetics to examine the relationships between bacterial community composition and soil respiration in samples through time. Pyrosequencing revealed that bacterial community composition explained 32 % of the variation in respiration rates. However, equal portions (i.e., 16 %) of the variation in bacterial community composition were explained by inoculum type and litter quality, reflecting the importance of both the meta-community and the environment in bacterial assembly. Taken together, these results indicate that the effects of changing microbial community composition on decomposition are likely to be smaller than the potential effects of climate change and/or litter quality changes in response to increasing atmospheric CO2 concentrations or atmospheric nutrient deposition.

Effect of Humic Acids and pesticides on Agricultural Soil Structure and Stability and Its Implication on Soil Quality

NASA Astrophysics Data System (ADS)

Gaonkar, O. D.; Nambi, I. M.; G, S. K.

2016-12-01

The functional and morphological aspects of soil structure determine the soil quality. The dispersion of colloidal soil particles, especially the clay fraction and rupture of soil aggregates, both of which play an important role in soil structure development, lead to degradation of soil quality. The main objective of this work was to determine the effect of behaviour of soil colloids on the agricultural soil structure and quality. The effect of commercial humic acid, organophosphate pesticides and soil natural organic matter on the electrical and structural properties of the soil colloids was also studied. Agricultural soil, belonging to the sandy loam texture class from northern part of India was considered in this study. In order to understand the changes in the soil quality in the presence and absence of humic acids, the soil fabric and structure was analyzed by X-ray diffraction (XRD), Fourier Transform Infrared (FTIR) Spectroscopy and Scanning Electron Microscopy (SEM). Electrical properties of natural soil colloids in aqueous suspensions were assessed by zeta potential measurements at varying pH values with and without the presence of humic acids and pesticides. The influence of natural organic matter was analyzed by oxidizing the natural soil organic matter with hydrogen peroxide. The zeta potential of the soil colloids was found to be negative in the pH range studied. The results indicated that hydrogen peroxide treatment lead to deflocculation of colloidal soil particles. In addition, the humic acids undergoes effective adsorption onto the soil surface imparting more negative zeta potential to the colloidal soil particles. The soil hydrophilicity decreased in the presence of humic acids which was confirmed by surface free energy determination. Thus, it can be concluded that the presence of humic acids altered the soil fabric and structure, thereby affecting the soil quality. This study assumes significance in understanding the soil aggregation and the interactions at soil solid-liquid interface.

Tillage and straw management affect PM10 emission potential in subarctic Alaska

USDA-ARS?s Scientific Manuscript database

Emission of PM10 (particulates =10 um in diameter regulated by many nations as an air pollutant) from agricultural soils can impact regional air quality. Little information exists that describes the potential for PM10 and airborne dust emissions from subarctic soils or agricultural soils subject to ...

Herbicide-resistant weeds threaten soil conservation gains: finding a balance for soil and farm sustainability

USDA-ARS?s Scientific Manuscript database

Tillage has been an integral part of agriculture since the dawn of civilization. Growers and scientists have long recognized both beneficial and detrimental aspects to tillage. There is no question that most tillage promotes soil loss, adversely affects surface water quality and negatively impacts...

Litter quality impacts short- but not long-term soil carbon dynamics in soil aggregate fractions.

PubMed

Gentile, Roberta; Vanlauwe, Bernard; Six, Johan

2011-04-01

Complex molecules are presumed to be preferentially stabilized as soil organic carbon (SOC) based on the generally accepted concept that the chemical composition of litter is a major factor in its rate of decomposition. Hence, a direct link between litter quality and SOC quantity has been assumed, accepted, and ultimately incorporated in SOC models. Here, however, we present data from an incubation and field experiment that refutes the influence of litter quality on the quantity of stabilized SOC. Three different qualities of litter (Tithonia diversifolia, Calliandra calothyrsus, and Zea mays stover; 4 Mg C x ha(-1) yr(-1)) with and without the addition of mineral N fertilizer (0 or 120 kg N x ha(-1)season(-1) were added to a red clay Humic Nitisol in a 3-yr field trial and a 1.5-yr incubation experiment. The litters differed in their concentrations of N, lignin, and polyphenols with the ratio of (lignin + polyphenols): N ranging from 3.5 to 9.8 for the field trial and from 2.3 to 4.0 for the incubation experiment in the order of T. diversifolia < C. calothyrsus < or = Z. mays. Litter quality did not affect the amount of SOC stabilized after three annual additions in the field trial. Even within the most sensitive soil aggregate fractions, SOC contents and C:N ratios did not differ with litter quality, indicating that litter quality did not influence the mechanisms by which SOC was stabilized. While increasing litter quality displayed faster decomposition and incorporation of C into soil aggregates after 0.25 yr in the incubation study, all litters resulted in equivalent amounts of C stabilized in the soil after 1.5 yr, further corroborating the results of the field trial. The addition of N fertilizer did not affect SOC stabilization in either the field or the incubation trial. Thus, we conclude that, while litter quality controls shorter-term dynamics of C decomposition and accumulation in the soil, longer-term SOC patterns cannot be predicted based on initial litter quality effects. Hence, the formation and stabilization of SOC is more controlled by the quantity of litter input and its interaction with the soil matrix than by litter quality.

Visible and infrared spectroscopy to evaluate soil quality in degraded sites: an applicative study in southern Italy

NASA Astrophysics Data System (ADS)

Ancona, Valeria; Matarrese, Raffaella; Salvatori, Rosamaria; Salzano, Roberto; Regano, Simona; Calabrese, Angelantonio; Campanale, Claudia; Felice Uricchio, Vito

2014-05-01

Land degradation processes like organic matter impoverishment and contamination are growing increasingly all over the world due to a non-rational and often sustainable spread of human activities on the territory. Consequently the need to characterize and monitor degraded sites is becoming very important, with the aim to hinder such main threats, which could compromise drastically, soil quality. Visible and infrared spectroscopy is a well-known technique/tool to study soil properties. Vis-NIR spectral reflectance, in fact, can be used to characterize spatial and temporal variation in soil constituents (Brown et al., 2006; Viscarra Rossel et al., 2006), and potentially its surface structure (Chappell et al., 2006, 2007). It is a rapid, non-destructive, reproducible and cost-effective analytical method to analyse soil properties and therefore, it can be a useful method to study land degradation phenomena. In this work, we present the results of proximal sensing investigations of three degraded sites (one affected by organic and inorganic contamination and two affected by soil organic matter decline) situated southern Italy close to Taranto city (in Apulia Region). A portable spectroradiometer (ASD-FieldSpec) was used to measure the reflectance properties in the spectral range between 350-2500 nm of the soil, in the selected sites, before and after a recovery treatment by using compost (organic fertilizer). For each measurement point the soil was sampled in order to perform chemical analyses to evaluate soil quality status. Three in-situ campaigns have been carried out (September 2012, June 2013, and September 2013), collecting about 20 soil samples for each site and for each campaign. Chemical and spectral analyses have been focused on investigating soil organic carbon, carbonate content, texture and, in the case of polluted site, heavy metals and organic toxic compounds. Statistical analyses have been carried out to test a prediction model of different soil quality indicators based on the spectral signatures behaviour of each sample ranging.

[Characteristics of soil microorganisms and soil nutrients in different sand-fixation shrub plantations in Kubuqi Desert, China].

PubMed

Zhang, Li-Xin; Duan, Yu Xi; Wang, Bo; Wang, Wei Feng; Li, Xiao Jing; Liu, Jin Jie

2017-12-01

Three types of sand-fixation shrub plantations, including Artemisia ordosica + Hedysarum fruticosum, Caragana korshinskii and Salix psammophila, were selected in the eastern area of Kubuqi Desert to study the changes in soil microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN), quantities of soil microorganisms, contents of soil nutrients and the relations among these variables under the different plantation types and shifting sandy land. The restoration effects of each plantation type on soil quality were assessed by synthetic index method. The results showed that the contents of soil organic matter, total nitrogen and phosphorus, and available nitrogen and phosphorus under different plantations were all significantly greater than those under shifting sandy land, and the order of increase was A. ordosica + H. fruticosum ＞ C. korshinskii ＞ S. psammophila. The soil nutrient contents decreased with the increase of soil depth under all plantation types. The quantities of soil microorganisms and the contents of soil MBC and MBN under the plantations were higher at different degrees than those under shifting sandy land. MBC, MBN and the relative numbers of bacteria under A. ordosica+H. fruticosum plantation were higher than those under C. korshinskii plantation and S. psammophila plantation. The relative numbers of fungi and actinobacteria decreased in the order of C. korshinskii ＞ S. psammophila ＞ A. ordosica + H. fruticosum. The relative number of bacteria, MBC and MBN under the plantations were mainly affected by the contents of soil organic matter, total nitrogen, total phosphorus, available nitrogen, available phosphorus, as well as C/N, and the relative numbers of actinobacteria and fungi were primarily affected by the contents of soil total phosphorus, available nitrogen and available phosphorus. Soil quality was ranked in the order of A. ordosica + H. fruticosum ＞ C. korshinskii ＞ S. psammophila ＞ shifting sandy land. These results demonstrated that different sand-fixation shrub plantations could improve the quality of the desert soil and the A. ordosica + H. fruticosum plantation was the best for soil restoration and quality improvement in the desert.

Physicochemical and biological quality of soil in hexavalent chromium-contaminated soils as affected by chemical and microbial remediation.

PubMed

Liao, Yingping; Min, Xiaobo; Yang, Zhihui; Chai, Liyuan; Zhang, Shujuan; Wang, Yangyang

2014-01-01

Chemical and microbial methods are the main remediation technologies for chromium-contaminated soil. These technologies have progressed rapidly in recent years; however, there is still a lack of methods for evaluating the chemical and biological quality of soil after different remediation technologies have been applied. In this paper, microbial remediation with indigenous bacteria and chemical remediation with ferrous sulphate were used for the remediation of soils contaminated with Cr(VI) at two levels (80 and 1,276 mg kg(-1)) through a column leaching experiment. After microbial remediation with indigenous bacteria, the average concentration of water-soluble Cr(VI) in the soils was reduced to less than 5.0 mg kg(-1). Soil quality was evaluated based on 11 soil properties and the fuzzy comprehensive assessment method, including fuzzy mathematics and correlative analysis. The chemical fertility quality index was improved by one grade using microbial remediation with indigenous bacteria, and the biological fertility quality index increased by at least a factor of 6. Chemical remediation with ferrous sulphate, however, resulted in lower levels of available phosphorus, dehydrogenase, catalase and polyphenol oxidase. The result showed that microbial remediation with indigenous bacteria was more effective for remedying Cr(VI)-contaminated soils with high pH value than chemical remediation with ferrous sulphate. In addition, the fuzzy comprehensive evaluation method was proven to be a useful tool for monitoring the quality change in chromium-contaminated soils.

Soils and public health: the vital nexus

NASA Astrophysics Data System (ADS)

Pachepsky, Yakov

2015-04-01

Soils sustain life. They affect human health via quantity, quality, and safety of available food and water, and via direct exposure of individuals to soils. Throughout the history of civilization, soil-health relationships have inspired spiritual movements, philosophical systems, cultural exchanges, and interdisciplinary interactions, and provided medicinal substances of paramount impact. Given the climate, resource, and population pressures, understanding and managing the soil-health interactions becomes a modern imperative. We are witnessing a paradigm shift from recognizing and yet disregarding the 'soil-health' nexus complexity to parameterizing this complexity and identifying reliable controls. This becomes possible with the advent of modern research tools as a source of 'big data' on multivariate nonlinear soil systems and the multiplicity of health metrics. The phenomenon of suppression of human pathogens in soils and plants presents a recent example of these developments. Evidence is growing about the dependence of pathogen suppression on the soil microbial community structure which, in turn, is affected by the soil-plant system management. Soil eutrophication appears to create favorable conditions for pathogen survival. Another example of promising information-rich research considers links and feedbacks between the soil microbial community structure and structure of soil physical pore space. The two structures are intertwined and involved in the intricate self-organization that controls soil services to public health. This, in particular, affects functioning of soils as a powerful water filter and the capacity of this filter with respect to emerging contaminants in both 'green' and 'blue' waters. To evaluate effects of soil services to public health, upscaling procedures are needed for relating the fine-scale mechanistic knowledge to available coarse-scale information on soil properties and management. More needs to be learned about health effects of soils in organic agriculture that are often used for soil quality comparison and benchmarking. The influence of soil degradation and rehabilitation on public health has to be assessed in quantitative terms. Some links between soils and public health regarding, for example, immune maturation, antibiotic resistance development, and mental well-being, have been long hypothesized but remain to be examined. The data on soil-health relationships are scarce and very much disjointed, and a concerted international effort appears to be needed to encompass various economic and geographical settings. Current definitions of healthy soil broadly include aspects that are conducive for human health, and functional evaluation of soil quality with a focus on public health will have useful applications in public policies and perception. The 'soil-health' connection is complex in character, global in manifestation, and applicable to every human being.

Effects of inorganic and organic amendment on soil chemical properties, enzyme activities, microbial community and soil quality in yellow clayey soil.

PubMed

Liu, Zhanjun; Rong, Qinlei; Zhou, Wei; Liang, Guoqing

2017-01-01

Understanding the effects of external organic and inorganic components on soil fertility and quality is essential for improving low-yielding soils. We conducted a field study over two consecutive rice growing seasons to investigate the effect of applying chemical fertilizer (NPK), NPK plus green manure (NPKG), NPK plus pig manure (NPKM), and NPK plus straw (NPKS) on the soil nutrient status, enzyme activities involved in C, N, P, and S cycling, microbial community and rice yields of yellow clayey soil. Results showed that the fertilized treatments significantly improved rice yields over the first three experimental seasons. Compared with the NPK treatment, organic amendments produced more favorable effects on soil productivity. Notably, the NPKM treatment exhibited the highest levels of nutrient availability, microbial biomass carbon (MBC), activities of most enzymes and the microbial community. This resulted in the highest soil quality index (SQI) and rice yield, indicating better soil fertility and quality. Significant differences in enzyme activities and the microbial community were observed among the treatments, and redundancy analysis showed that MBC and available N were the key determinants affecting the soil enzyme activities and microbial community. The SQI score of the non-fertilized control (0.72) was comparable to that of the NPK (0.77), NPKG (0.81) and NPKS (0.79) treatments but significantly lower compared with NPKM (0.85). The significant correlation between rice yield and SQI suggests that SQI can be a useful to quantify soil quality changes caused by different agricultural management practices. The results indicate that application of NPK plus pig manure is the preferred option to enhance SOC accumulation, improve soil fertility and quality, and increase rice yield in yellow clayey soil.

Effects of inorganic and organic amendment on soil chemical properties, enzyme activities, microbial community and soil quality in yellow clayey soil

PubMed Central

Liu, Zhanjun; Rong, Qinlei; Zhou, Wei; Liang, Guoqing

2017-01-01

Understanding the effects of external organic and inorganic components on soil fertility and quality is essential for improving low-yielding soils. We conducted a field study over two consecutive rice growing seasons to investigate the effect of applying chemical fertilizer (NPK), NPK plus green manure (NPKG), NPK plus pig manure (NPKM), and NPK plus straw (NPKS) on the soil nutrient status, enzyme activities involved in C, N, P, and S cycling, microbial community and rice yields of yellow clayey soil. Results showed that the fertilized treatments significantly improved rice yields over the first three experimental seasons. Compared with the NPK treatment, organic amendments produced more favorable effects on soil productivity. Notably, the NPKM treatment exhibited the highest levels of nutrient availability, microbial biomass carbon (MBC), activities of most enzymes and the microbial community. This resulted in the highest soil quality index (SQI) and rice yield, indicating better soil fertility and quality. Significant differences in enzyme activities and the microbial community were observed among the treatments, and redundancy analysis showed that MBC and available N were the key determinants affecting the soil enzyme activities and microbial community. The SQI score of the non-fertilized control (0.72) was comparable to that of the NPK (0.77), NPKG (0.81) and NPKS (0.79) treatments but significantly lower compared with NPKM (0.85). The significant correlation between rice yield and SQI suggests that SQI can be a useful to quantify soil quality changes caused by different agricultural management practices. The results indicate that application of NPK plus pig manure is the preferred option to enhance SOC accumulation, improve soil fertility and quality, and increase rice yield in yellow clayey soil. PMID:28263999

Geo-Specific disease and the Stroke Belt: Do soils play a role in stroke mortality?

USDA-ARS?s Scientific Manuscript database

The concept of geo-specific disease is commonly associated with socio-economic factors, such as income and education that can affect the incidence of preventable diseases. However, geo-specific diseases may also be influenced by environmental factors, such as soil and water quality. Local soil and w...

Eco-evolutionary processes affecting plant-herbivore interactions during early community succession.

PubMed

Howard, Mia M; Kalske, Aino; Kessler, André

2018-06-01

The quality and outcome of organismal interactions are not only a function of genotypic composition of the interacting species, but also the surrounding environment. Both the strength and direction of natural selection on interacting populations vary with the community context, which itself is changed by these interactions. Here, we test for the role of interacting evolutionary and ecological processes in plant-herbivore interactions during early community succession in the tall goldenrod, Solidago altissima. We use surveys in a large-scale field experiment with repeated plots representing 6 years of early oldfield succession and reciprocal transplant common garden experiments to test for the relative importance of rapid evolution (genetic) and environmental changes (soil quality) in affecting mean plant resistance and growth phenotypes during community succession. While plant growth varied strongly with soil quality over the first 5 years of agricultural abandonment, plant secondary metabolism, and herbivore resistance varied minimally with the soil environment. Instead, mean composition and abundance of plant secondary compound bouquets differed between S. altissima plants from populations collected in communities in the first ("early") and sixth ("intermediate") years of oldfield succession, which was reflected in the feeding preference of the specialist herbivore, Trirhabda virgata, for early succession lines. Moreover, this preference was most pronounced on poorer quality, early succession soils. Overall, our data demonstrate that plant quality varies for insect herbivores during the course of early succession and this change is a combination of altered genotypic composition of the population and phenotypic plasticity in different soil environments.

78 FR 50358 - Notice of Intent To Prepare an Environmental Impact Statement for the Proposed Rule, Standards...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-19

... proposed action may significantly affect the quality of the human environment (21 CFR 25.22(b)) and... response to a microbial standard, may significantly affect the quality of the human environment. Similarly, comments received caused FDA to reevaluate the proposed requirements for biological soil amendments of...

Hillslope erosion rates in the oak savannas of the southwestern borderlands region

Treesearch

Aaron T. Kauffman; Cody L. Stropki; Peter F. Ffolliott; Gerald J. Gottfried; Daniel G. Neary

2007-01-01

Hillslope soil erosion on watershed landscapes can lower the productivity of upland sites and adversely impact water quality and downstream (off-site) areas. It is not surprising, therefore, that excessive soil erosion and the consequent sedimentation can represent significant costs to the land and people that are affected. The first known estimates of hillslope soil...

Influence of irrigation during the growth stage on yield and quality in mango (Mangifera indica L)

PubMed Central

Wei, Junya; Liu, Guoyin; Liu, Debing; Chen, Yeyuan

2017-01-01

Although being one of the few drought-tolerant plants, mango trees are irrigated to ensure optimum and consistent productivity in China. In order to better understand the effects of soil water content on mango yield and fruit quality at fruit growth stage, irrigation experiments were investigated and the object was to determine the soil water content criteria at which growth and quality of mango would be optimal based on soil water measured by RHD-JS water-saving irrigation system through micro-sprinkling irrigation. Five soil water content treatments (relative to the percentage of field water capacity) for irrigation (T1:79%-82%, T2:75%-78%, T3:71%-74%, T4: 65%-70%, T5:63%-66%) were compared in 2013. Amount of applied irrigation water for different treatments varied from 2.93m3 to 1.08 m3. The results showed that mango fruit production and quality at fruit growth stage were significantly affected under different irrigation water amounts. Variation in soil water content not only had effects on fruit size, but also on fruit yield. The highest fruit yield and irrigation water use efficiency were obtained from the T4 treatment. Irrigation water amount also affected fruit quality parameters like fruit total soluble solids, soluble sugar, starch, titratable acid and vitamin C content. Comprehensive evaluation of the effect of indexs of correlation on irrigation treatment by subordinate function showed that when the soil moisture content were controlled at about 65–70% of the field water moisture capacity, water demand in the growth and development of mango could be ensured, and maximum production efficiency of irrigation and the best quality of fruit could be achieved. In conclusion, treatment T4 was the optimum irrigation schedule for growing mango, thus achieving efficient production of mango in consideration of the compromise among mango yield, fruit quality and water use efficiency. PMID:28384647

Influence of irrigation during the growth stage on yield and quality in mango (Mangifera indica L).

PubMed

Wei, Junya; Liu, Guoyin; Liu, Debing; Chen, Yeyuan

2017-01-01

Although being one of the few drought-tolerant plants, mango trees are irrigated to ensure optimum and consistent productivity in China. In order to better understand the effects of soil water content on mango yield and fruit quality at fruit growth stage, irrigation experiments were investigated and the object was to determine the soil water content criteria at which growth and quality of mango would be optimal based on soil water measured by RHD-JS water-saving irrigation system through micro-sprinkling irrigation. Five soil water content treatments (relative to the percentage of field water capacity) for irrigation (T1:79%-82%, T2:75%-78%, T3:71%-74%, T4: 65%-70%, T5:63%-66%) were compared in 2013. Amount of applied irrigation water for different treatments varied from 2.93m3 to 1.08 m3. The results showed that mango fruit production and quality at fruit growth stage were significantly affected under different irrigation water amounts. Variation in soil water content not only had effects on fruit size, but also on fruit yield. The highest fruit yield and irrigation water use efficiency were obtained from the T4 treatment. Irrigation water amount also affected fruit quality parameters like fruit total soluble solids, soluble sugar, starch, titratable acid and vitamin C content. Comprehensive evaluation of the effect of indexs of correlation on irrigation treatment by subordinate function showed that when the soil moisture content were controlled at about 65-70% of the field water moisture capacity, water demand in the growth and development of mango could be ensured, and maximum production efficiency of irrigation and the best quality of fruit could be achieved. In conclusion, treatment T4 was the optimum irrigation schedule for growing mango, thus achieving efficient production of mango in consideration of the compromise among mango yield, fruit quality and water use efficiency.

Relationships between Soil and Levels of Meloidogyne incognita and Tobacco Yield and Quality.

PubMed

Barker, K R; Weeks, W W

1991-01-01

A 2-year study with six soils and four levels of Meloidogyne incognita in microplots was designed to determine the effects of these parameters on nematode activity and tobacco yield and quality. Key components under study were affected by soil, nematode level, and season (year-cultivar). In 1980, low initial nematode numbers (1,250) enhanced tobacco yield in Cecil clay loam, but caused slight to moderate yield losses in the other soils. Yield losses to M. incognita were generally greatest in sandy and muck soils. In 1980, regression analyses of the independent parameters Pi - clay-sand vs. yield gave an R(2) of 0.40. Examples of other coefficients of determination for yield vs. selected factors were root-necrosis index, 0.40; root-gall index, 0.18; root-gall index-cation exchange capacity (CEC), 0.34; root-necrosis index-CEC, 0.56; and root-necrosis index-sand-soil acidity-calcium, 0.62. In contrast, the R(2) for Pi alone versus yield in 1981 was 0.84. Soil also affected nematode reproduction with the greatest increases occurring in the sandy soils. In both years, low nematode numbers enhanced the synthesis of sugar in tobacco, whereas leaves from all other nematode treatments had low sugar levels. A low nicotine content was associated with nematode infection. Tobacco from sandy soils had a higher nicotine content than tobacco from clay soils.

Soil fauna, soil properties and geo-ecosystem functioning

NASA Astrophysics Data System (ADS)

Cammeraat, L. H.

2012-04-01

The impact of soil fauna on soil processes is of utmost importance, as the activity of soil fauna directly affects soil quality. This is expressed by the direct effects of soil fauna on soil physical and soil chemical properties that not only have great importance to food production and ecosystems services, but also on weathering and hydrological and geomorphological processes. Soil animals can be perceived as ecosystem engineers that directly affect the flow of water, sediments and nutrients through terrestrial ecosystems. The biodiversity of animals living in the soil is huge and shows a huge range in size, functions and effects. Most work has been focused on only a few species such as earthworms and termites, but in general the knowledge on the effect of soil biota on soil ecosystem functioning is limited as it is for their impact on processes in the soil and on the soil surface. In this presentation we would like to review some of the impacts of soil fauna on soil properties that have implications for geo-ecosystem functioning and soil formation processes.

Study of microarthopod communities to assess soil quality in different managed vineyards

NASA Astrophysics Data System (ADS)

Gagnarli, E.; Goggioli, D.; Tarchi, F.; Guidi, S.; Nannelli, R.; Vignozzi, N.; Valboa, G.; Lottero, M. R.; Corino, L.; Simoni, S.

2015-01-01

Land use influences the abundance and diversity of soil arthropods. The evaluation of the impact of different management strategies on soil quality is increasingly requested. The determination of communities' structures of edaphic fauna can represent an efficient tool. In this study, in some vineyards in Piedmont (Italy), the effects of two different management systems, organic and integrated pest management (IPM), on soil biota were evaluated. As microarthropods living in soil surface are an important component of soil ecosystem interacting with all the other system components, a multi disciplinary approach was adopted by characterizing also some soil physical and chemical characteristics (soil texture, soil pH, total organic carbon, total nitrogen, calcium carbonate). Soil samplings were carried out on Winter 2011 and Spring 2012. All specimens were counted and determined up to the order level. The biological quality of the soil was defined through the determination of ecological indices, such as QBS-ar, species richness and indices of Shannon-Weaver, Pielou, Margalef and Simpson. The mesofauna abundance was affected by both the type of management and the soil texture. The analysis of microarthropod communities by QBS-ar showed higher values in organic than in IPM managed vineyards; in particular, the values registered in organic vineyards were similar to those characteristic of preserved soils.

From the study of fire effects on individual soil properties to the development of soil quality indices. 1. The pioneer research

NASA Astrophysics Data System (ADS)

Mataix-Solera, Jorge; Zornoza, Raúl

2013-04-01

Although forest fires must be considered as a natural factor in Mediterranean ecosystems, the modification of its natural regime during last five decades has thansformed them in an environmental problem. In the Valencia region (E Spain) 1994 was the worst year in the history affecting more than 120,000 hectares. I started my Ph.D that year by studying the effects of fires in soil properties. The availability to be able to analyse a great set of different types of soil properties in the laboratories of University of Alicante allowed me to explore how fires could affect physical, chemical and micobiological soil properties. After years studying different soil properties, finding that several factors are involved, including: fire intensity and severity, vegetation, soil type, climate conditions, etc. (Mataix-Solera and Doerr, 2004; Mataix-Solera et al., 2008, 2011) my research as Ph-D supervisor has been focussed to investigate more in depth some selected properties, such as aggregate stability and water repellency (Arcenegui et al., 2007, 2008). But one of the main problems in the studies conducted with samples affected by wildfires is that for the evaluation of the fire impact in the soil it is necessary to have control (unburned) soil samples from a similar non-affected near area. The existing spatial variability under field conditions does not allow having comparable samples in some acses to develop a correct assessment. With this idea in mind one of my Ph.D researcher (R. Zornoza) dedicated his thesis to develope soil quality indices capable to assess the impact of soil perturbations without comparing groups of samples, but evaluating the equilibrium among different soil properties within each soil sample (Zornoza et al., 2007, 2008). Key words: wildfire, Mediterranean soils, soil degradation, wàter repellency, aggregate stability References: Arcenegui, V., Mataix-Solera, J., Guerrero, C., Zornoza, R., Mayoral, A.M., Morales, J., 2007. Factors controlling the water repellency induced by fire in calcareous Mediterranean forest soils. Eur. J. Soil Sci. 58, 1254-1259. Arcenegui, V., Mataix-Solera, J., Guerrero, C., Zornoza, R., Mataix-Beneyto, J., García-Orenes, F., 2008. Immediate effects of wildfires on water repellency and aggregate stability in Mediterranean calcareous soils. Catena 74, 219-226. Mataix-Solera, J., Doerr, S.H., 2004. Hydrophobicity and aggregate stability in calcareous topsoil from fire affected pine forests in southeastern Spain. Geoderma 118, 77-88. Mataix-Solera, J., Arcenegui, V., Guerrero, C., Jordán, M., Dlapa, P., Tessler, N., Wittenberg, L. 2008. Can terra rossa become water repellent by burning? A laboratory approach. Geoderma, 147, 178-184. Mataix-Solera, J., Cerdà, A., Arcenegui, V., Jordán, A., Zavala, L.M., 2011. Fire effects on soil aggregation: a review. Earth-Science Reviews 109, 44-60 Zornoza, R., Mataix-Solera, J., Guerrero, C., Arcenegui, V., Mayoral, A.M., Morales, J. Mataix-Beneyto, J., 2007b. Soil properties under natural forest in the Alicante Province of Spain. Geoderma. 142, 334-341. Zornoza, R., Mataix-Solera, J., Guerrero, C., Arcenegui, V., Mataix-Beneyto, J., Gómez, I., 2008. Validating the effectiveness and sensitivity of two soil quality indices based on natural forest soils under Mediterranean conditions. Soil Biology & Biochemistry. 40, 2079-2087.

Water quality, sediment, and soil characteristics near Fargo-Moorhead urban areas as affected by major flooding of the Red River of the North.

PubMed

Guy, A C; Desutter, T M; Casey, F X M; Kolka, R; Hakk, H

2012-01-01

Spring flooding of the Red River of the North (RR) is common, but little information exits on how these flood events affect water and overbank sediment quality within an urban area. With the threat of the spring 2009 flood in the RR predicted to be the largest in recorded history and the concerns about the flooding of farmsteads, outbuildings, garages, and basements, the objectives of this study, which focused on Fargo, ND, and Moorhead, MN, were to assess floodwater quality and to determine the quantity and quality of overbank sediment deposited after floodwaters recede and the quality of soil underlying sediment deposits. 17β-Estradiol was detected in 9 of 24 water samples, with an average concentration of 0.61 ng L. Diesel-range organics were detected in 8 of 24 samples, with an average concentration of 80.0 μg L. The deposition of sediment across locations and transects ranged from 2 to 10 kg m, and the greatest mass deposition of chemicals was closest to the river channel. No gasoline-range organics were detected, but diesel-range organics were detected in 26 of the 27 overbank sediment samples (maximum concentration, 49.2 mg kg). All trace elements detected in the overbank sediments were within ranges for noncontaminated sites. Although flooding has economic, social, and environmental impacts, based on the results of this study, it does not appear that flooding in the RR in F-M led to decreased quality of water, sediment, or soil compared with normal river flows or resident soil. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

78 FR 69460 - Proposed License Renewal of the Prairie Island Independent Spent Fuel Storage Installation

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-19

...; climatology, meteorology and air quality; geology and soils; water resources; ecology and threatened and... significantly affect the quality of the human environment. No significant changes in NSPM's authorized...

Effect of different kinds of crop residues on aggregate-protected soil organic matter fractions.

NASA Astrophysics Data System (ADS)

Huisz, A.

2009-04-01

Organic matter content of soils determines many important soil properties, such as soil structure, fertility and water-management. To improve its fertility and quality, returning different kinds of organic matter to soil has a long historical tradition. Ameliorating of soil and enhancing its fertility by enhancing its carbon stock with organic matter incorporation (like farmyard manure, crop residues or green manure) are general practices, but the extent of the amelioration depends much on several factors such as quantity, quality of the used organic matters. Quality of soil organic matters is affected by their chemical build-up, which differs by their origin (i.e. plant species); and their decomposability is affected by particle-size, protection by soil aggregates and the extent of their association to mineral surfaces. In our paper we investigated the effect of three different kinds of organic matter incorporation on aggregate-protected organic matter fractions: (1) Maize stem (M), (2) Wheat straw (W), and (3) Maize stem & Wheat straw (MW). Our samples were originated from Keszthely, Western Hungary, where the texture of the investigated soil is Sandy loam, the type of soil is Eutric Cambisol (soil type FAO), or Alfisol (soil type USDA). SOM fractions might be isolated and measured by physical fractionation of soil (Cambardella and Elliott (1992), Jensen et al. (1992)). Firstly, microaggregates were separated according to their particle-size with physical fractionation (i.e. wet sieving) (Six et al. (2000a)). Each sample was pre-treated by capillary wetting and was sieved for 2 min in an analytic sieve shaker machine with the following aperture sizes: 2 mm, 250 μm, 53 μm. Therefore 4 fractions were resulted: (1) the >2000 μm large macro-, (2) the 250-2000 μm small macro-, (3) the 53-250 μm microaggregates, and (4) the

Soil Organic Matter Quality of an Oxisol Affected by Plant Residues and Crop Sequence under No-Tillage

NASA Astrophysics Data System (ADS)

Cora, Jose; Marcelo, Adolfo

2013-04-01

Plant residues are considered the primarily resource for soil organic matter (SOM) formation and the amounts and properties of plant litter are important controlling factors for the SOM quality. We determined the amounts, quality and decomposition rate of plant residues and the effects of summer and winter crop sequences on soil organic C (TOC) content, both particulate organic C (POC) and mineral-associated organic C (MOC) pools and humic substances in a Brazilian Rhodic Eutrudox soil under a no-tillage system. The organic C analysis in specifics pools used in this study was effective and should be adopted in tropical climates to evaluate the soil quality and the sustainability of various cropping systems. Continuous growth of soybean (Glycine max L. Merrill) on summer provided higher contents of soil POC and continuous growth of maize (Zea mays L.) provided higher soil humic acid and MOC contents. Summer soybean-maize rotation provided the higher plant diversity, which likely improved the soil microbial activity and the soil organic C consumption. The winter sunn hemp (Crotalaria juncea L.), pigeon pea (Cajanus cajan (L.) Millsp), oilseed radish (Raphanus sativus L.) and pearl millet (Pennisetum americanum (L.) Leeke) enhanced the soil MOC, a finding that is attributable to the higher N content of the crop residue. Sunn hemp and pigeon pea provided the higher soil POC content. Sunn hemp showed better performance and positive effects on the SOM quality, making it a suitable winter crop choice for tropical conditions with a warm and dry winter.

The influence of the annual invasive plant, Impatiens glandulifera, on the sediment dynamics of inland watercourses in temperate regions

NASA Astrophysics Data System (ADS)

Dalvi, Shrutika; Greenwood, Philip

2016-04-01

Impatiens glandulifera (Common English Name - Himalayan Balsam) is a non native annual and highly invasive plant that was introduced into parts of Europe from the Himalaya during the nineteenth century as a colourful adornment to parks and gardens. This Plant colonises areas along the river banks, preferably wet, depositional sites, and displaces natural vegetation. The plant is killed by cold weather. The leaves area of riverbank previously occupied by the plant extremely vulnerable to soil erosion until new plant germinates in the following spring. Research work undertaken in the northwest Switzerland and the soutwestern United Kingdom established s link between accelerated soil erosion caused by Impatiens glandulifera and its detrimental impact on native biodiversity of riparian zone of river catchment area. This study focueses on the potential impact of such erosion on sediment quality. A priory reasoning suggests that the preference of Impatiens glandulifera on young depsotional sites near watercourses affects sediment quality. In this study, the results of a soil quality analysis along Impatiens glandulifera-contaminated river banks is presented. Soil physical and chemical properties are compared to non-affected sites to assess the potential impact of preferential erosion on water quality. In addtiion, soil surface profile (SSP) measuring based on by erosion pins, a micro profile bridge and a digital calliper at different selected locations along the riparian zone of river catchment area is used to determine erosion rates and determine sediment transfer from the riparian zone into the rivers.

Analytical tools for assessing land degradation and its impact on soil quality

NASA Astrophysics Data System (ADS)

Bindraban, P. S.; Mantel, S.; Bai, Z.; de Jong, R.

2010-05-01

Maintaining and enhancing the quality of land is of major importance to sustain future production capacity for food and other agriculture based products like fibers and wood, and for maintaining ecosystems services, including below and above ground biodiversity, provision of soil water and sequestration of carbon. Deterioration of this production base will be detrimental to the provision of the foreseen dramatic increase in human needs for goods and services. For this reason, land degradation, defined as a long-term loss in ecosystem function and productivity, has to be understood properly. Climate, soils, topography and socioeconomic activities are primary factors that can cause, by themselves or in combination, a number of temporary or permanent changes in the landscape, leading to degradation of vegetation and soils. For identifying intervention measures to prevent and revert trends of land deterioration, it is fundamental to know the extent of land degradation and to understand its impact on functional properties of land. To assess the global extent, (Bai et al. 2008) apply a remotely sensed vegetation index that describes the greenness of the vegetation cover as a proxy for biomass. Biomass production has been identified as a strong indicator for soil quality as it is an integral measure for soil, crop and environmental characteristics (Bindraban et al., 2000). Bai and colleagues observed that 24% of the global land has been degrading over the past 26 years - often in very productive areas. The relation with functional properties of land can be made through ecosystem models. Mantel et al. (1999; 2000) applied dynamic crop-soil models to calculate crop productivity at the national level. A baseline scenario that represents the current conditions and a scenario for 20 years of prolonged sheet erosion were modeled to calculate the productivity impact of topsoil erosion for wheat in Uruguay and for maize in Kenya. They concluded that topsoil erosion primarily affects nutrient availability; in 20% of the potential maize growing areas productivity declined more then 50%. Overall, hydraulic soil functions were less affected by erosion in Kenya, still rain-fed yield decline exceeded 50 % on very steep lands. The simulated loss of topsoil in the Uruguay case mostly affected soil physical properties causing a reduction in rainfed wheat yields. Soil fertility status was little affected. In this paper we reflect on the use and effectiveness of these two approaches and discuss options for their (partial) integration as a means to better quantify extent, degree of degradation and the effects on soil quality. References Bai ZG, Dent DL, Olsson L and Schaepman ME 2008. Proxy global assessment of land degradation. Soil Use and Management 24, 223-234 Bindraban PS, Stoorvogel JJ, Jansen DM, Vlaming J and Groot JJR 2000. Land quality indicators for sustainable land management: proposed method for yield gap and soil nutrient balance. Agriculture, Ecosystems and the Environment 81, 103-112 Mantel S and van Engelen VWP 1999. Assessment of the impact of water erosion on productivity of maize in Kenya: an integrated modelling approach. Land Degradation & Development 10, 577-592 Mantel S, van Engelen VWP, Molfino JH and Resink JW 2000. Exploring biophysical potential and sustainability of wheat cultivation in Uruguay at the national level. Soil Use and Management 16, 270-278

Electrical resistivity tomography to delineate greenhouse soil variability

NASA Astrophysics Data System (ADS)

Rossi, R.; Amato, M.; Bitella, G.; Bochicchio, R.

2013-03-01

Appropriate management of soil spatial variability is an important tool for optimizing farming inputs, with the result of yield increase and reduction of the environmental impact in field crops. Under greenhouses, several factors such as non-uniform irrigation and localized soil compaction can severely affect yield and quality. Additionally, if soil spatial variability is not taken into account, yield deficiencies are often compensated by extra-volumes of crop inputs; as a result, over-irrigation and overfertilization in some parts of the field may occur. Technology for spatially sound management of greenhouse crops is therefore needed to increase yield and quality and to address sustainability. In this experiment, 2D-electrical resistivity tomography was used as an exploratory tool to characterize greenhouse soil variability and its relations to wild rocket yield. Soil resistivity well matched biomass variation (R2=0.70), and was linked to differences in soil bulk density (R2=0.90), and clay content (R2=0.77). Electrical resistivity tomography shows a great potential in horticulture where there is a growing demand of sustainability coupled with the necessity of stabilizing yield and product quality.

Effect of mismanagement at the state of organic matter in soil

NASA Astrophysics Data System (ADS)

Hladký, Jan; Elbl, Jakub; Kynický, Jindřich; Dvořáčková, Helena; Juřička, David; Pecina, Václav; Brtnický, Martin

2017-04-01

Organic matter is an essential part of the soil. It affects the physical, chemical, and biological properties of the soil. It is therefore necessary to maintain organic matter in the soil and its quality as the prevention of soil degradation. Loss of organic matter is in the Czech Republic threatened up to 45% of arable soil. The most important reason for the loss of organic matter in the soil is poor management, especially improper crop rotation, cultivation of erosion-prone crops where erosion takes away valuable topsoil with nutrients and organic matter. The aim of our study was to verify the influence of inappropriate management on selected 5 plots in southern Moravia in the Czech Republic. It is the region with the highest incidence of water erosion in the Czech Republic. Were selected plots with significantly sloping, where corn was grown. Samples were taken in the autumn after the harvest, each of topsoil. The sampling sites were placed in positions on the slope where soil was not damaged by erosion, as well as the place greatest damage and the place where washed soil was accumulated. Soil average humus content was for undamaged position on the slope 1.93% and 0.84 quality, the most heavily damaged part of the slope humus content dropped to 1.35% and its quality at only 0.56. In the case of position of accumulated soils was found the average amount of humus 1.70% and 0.90 quality. Humus content and its quality is statistically significantly influenced by water erosion (α = 0.05). The study showed that bad management, when there is not crop rotation adapted to the given conditions and not subjected to any suitable soil-protecting technologies, there is significant damage to soils, which shows mainly organic matter decline and a decline in its quality. Continuation of our study will verify the possibility of stabilization of soil organic matter and draft appropriate technologies.

Forest composition modifies litter dynamics and decomposition in regenerating tropical dry forest.

PubMed

Schilling, Erik M; Waring, Bonnie G; Schilling, Jonathan S; Powers, Jennifer S

2016-09-01

We investigated how forest composition, litter quality, and rainfall interact to affect leaf litter decomposition across three successional tropical dry forests in Costa Rica. We monitored litter stocks and bulk litter turnover in 18 plots that exhibit substantial variation in soil characteristics, tree community structure, fungal communities (including forests dominated by ecto- or arbuscular mycorrhizal host trees), and forest age. Simultaneously, we decomposed three standard litter substrates over a 6-month period spanning an unusually intense drought. Decay rates of standard substrates depended on the interaction between litter identity and forest type. Decomposition rates were correlated with tree and soil fungal community composition as well as soil fertility, but these relationships differed among litter types. In low fertility soils dominated by ectomycorrhizal oak trees, bulk litter turnover rates were low, regardless of soil moisture. By contrast, in higher fertility soils that supported mostly arbuscular mycorrhizal trees, bulk litter decay rates were strongly dependent on seasonal water availability. Both measures of decomposition increased with forest age, as did the frequency of termite-mediated wood decay. Taken together, our results demonstrate that soils and forest age exert strong control over decomposition dynamics in these tropical dry forests, either directly through effects on microclimate and nutrients, or indirectly by affecting tree and microbial community composition and traits, such as litter quality.

Conservation agriculture among small scale farmers in semi-arid region of Kenya does improve soil biological quality and soil organic carbon

NASA Astrophysics Data System (ADS)

Waweru, Geofrey; Okoba, Barrack; Cornelis, Wim

2016-04-01

The low food production in Sub-Saharan Africa (SSA) has been attributed to declining soil quality. This is due to soil degradation and fertility depletion resulting from unsustainable conventional farming practices such as continuous tillage, crop residue burning and mono cropping. To overcome these challenges, conservation agriculture (CA) is actively promoted. However, little has been done in evaluating the effect of each of the three principles of CA namely: minimum soil disturbance, maximum surface cover and diversified/crop rotation on soil quality in SSA. A study was conducted for three years from 2012 to 2015 in Laikipia East sub county in Kenya to evaluate the effect of tillage, surface cover and intercropping on a wide variety of physical, chemical and biological soil quality indicators, crop parameters and the field-water balance. This abstract reports on soil microbial biomass carbon (SMBC) and soil organic carbon (SOC). The experimental set up was a split plot design with tillage as main treatment (conventional till (CT), no-till (NT) and no-till with herbicide (NTH)), and intercropping and surface cover as sub treatment (intercropping maize with: beans, MB; beans and leucaena, MBL; beans and maize residues at 1.5 Mg ha-1 MBMu, and dolichos, MD). NT had significantly higher SMBC by 66 and 31% compared with CT and NTH respectively. SOC was significantly higher in NTH than CT and NT by 15 and 4%, respectively. Intercropping and mulching had significant effect on SMBC and SOC. MBMu resulted in higher SMBC by 31, 38 and 43%, and SOC by 9, 20 and 22% as compared with MBL, MD and MB, respectively. SMBC and SOC were significantly affected by the interaction between tillage, intercropping and soil cover with NTMBMu and NTHMBMu having the highest SMBC and SOC, respectively. We conclude that indeed tillage, intercropping and mulching substantially affect SMBC and SOC. On the individual components of CA, tillage and surface cover had the highest effect on SMBC and SOC, respectively, but the highest positive effect was realized when all the three principles were applied consecutively. Therefore, CA has the potential to improve biological soil quality among small scale rainfed farmers and thus promote sustainable production.

7 CFR 650.9 - NEPA and interagency planning.

Code of Federal Regulations, 2010 CFR

2010-01-01

... affect areas of NRCS expertise, such as prime farmlands, soils, erosion control, and agricultural sources of nonpoint pollution. NRCS, as a cooperating agency, is to comply with the requirements of 40 CFR... appointed to insure that soil, water, related resources, and environmental qualities in the district are...

Does Gray-Tailed Vole Activity Affect Soil Quality?

USDA-ARS?s Scientific Manuscript database

Voles are well-known crop pests, especially when peak populations are present, but their role in soil fertility and impacts on agricultural sustainability are not well understood. Five months after the abrupt disappearance of a peak in a gray-tailed vole (Microtus canicaudus) population, we examined...

Response of detritus food web and litter quality to elevated CO2 and crop cultivars and their feedback to soil functionality

NASA Astrophysics Data System (ADS)

Hu, Zhengkun; Chen, Xiaoyun; Zhu, Chunwu; Bonkowski, Michael; Hu, Shuijin; Li, Huixin; Hu, Feng; Liu, Manqiang

2017-04-01

Elevated atmospheric CO2 concentrations (eCO2) often increase plant growth and alter the belowground detritus soil food web. Interactions with agriculture management may further modify soil process and the associated ecosystem functionality. Little attention, however, has been directed toward assessing the responses of soil food web and their feedback to soil functionality, particularly in wetland agroecosystems. We report results from a long-term free air CO2 enrichment (FACE) experiment in a rice paddy field that examined the responses of detritus food webs to eCO2 (200 ppm higher than ambient CO2 (aCO2)) of two rice cultivars with distinctly weak and strong responses to eCO2. Soil detritus food web components, including soil microbes and microfauna, soil environment as well as resources availability variables, were determined at the rice ripening stage. To obtain the information of soil functionality, indicated by litter decomposition and enzyme activities, we adopted a reciprocal transplant approach that fully manipulate the factors of litter straw and food web components for the incubation of 120 days. Results about the field investigation showed that eCO2 lead to a higher C/N ratio of litter and soil compared to aCO2, especially for the strong responsive cultivar. eCO2-induced enhanced carbon input stimulated the fungal decomposition pathway by increasing fungal biomass, fungi: bacteria ratio and fungivorous nematode. Results from the manipulative incubation experiment showed eCO2-induced lower quality of straw decreased cumulative C mineralization, but changes in detritus food web induced by eCO2 and strongly responsive cultivar lead to an increased CO2 respiration coincidently within each straw type, mainly due to the adaption to the high C/N ratio environment which increased their functional breadth. Based on SEMs and curves of carbon mineralization rate, soil communities showed significant effects on C release at the early stage through mediating enzyme activities involved in carbon and nutrient cycling. Our results indicated that resource quality played a pivotal role in mediating soil functionality as it primarily determined the rate and degree of decomposition, but soil community composition could modify how resource quality affected this soil process. eCO2 and crop cultivar migration significantly altered straw quality and soil community composition, and thus affected soil functioning. Our findings highlight that alterations of soil functional guilds under future climate and appropriate agricultural strategy change the carbon and nutrient cycling of ecosystem. Key-words: Global change; Nitrogen input; Crop cultivar; Rhizosphere food webs; Root microbiome; Microbial community; Soil fauna

Soil conservation applications with C-band SAR

NASA Technical Reports Server (NTRS)

Brisco, B.; Brown, R. J.; Naunheimer, J.; Bedard, D.

1992-01-01

Soil conservation programs are becoming more important as the growing human population exerts greater pressure on this non-renewable resource. Indeed, soil degradation affects approximately 10 percent of Canada's agricultural land with an estimated loss of 6,000 hectares of topsoil annually from Ontario farmland alone. Soil loss not only affects agricultural productivity but also decreases water quality and can lead to siltation problems. Thus, there is a growing demand for soil conservation programs and a need to develop an effective monitoring system. Topography and soil type information can easily be handled within a geographic information system (GIS). Information about vegetative cover type and surface roughness, which both experience considerable temporal change, can be obtained from remote sensing techniques. For further development of the technology to produce an operational soil conservation monitoring system, an experiment was conducted in Oxford County, Ontario which investigated the separability of fall surface cover type using C-band Synthetic Aperture Radar (SAR) data.

Impacts of crop growth dynamics on soil quality at the regional scale

NASA Astrophysics Data System (ADS)

Gobin, Anne

2014-05-01

Agricultural land use and in particular crop growth dynamics can greatly affect soil quality. Both the amount of soil lost from erosion by water and soil organic matter are key indicators for soil quality. The aim was to develop a modelling framework for quantifying the impacts of crop growth dynamics on soil quality at the regional scale with test case Flanders. A framework for modelling the impacts of crop growth on soil erosion and soil organic matter was developed by coupling the dynamic crop cover model REGCROP (Gobin, 2010) to the PESERA soil erosion model (Kirkby et al., 2009) and to the RothC carbon model (Coleman and Jenkinson, 1999). All three models are process-based, spatially distributed and intended as a regional diagnostic tool. A geo-database was constructed covering 10 years of crop rotation in Flanders using the IACS parcel registration (Integrated Administration and Control System). Crop allometric models were developed from variety trials to calculate crop residues for common crops in Flanders and subsequently derive stable organic matter fluxes to the soil. Results indicate that crop growth dynamics and crop rotations influence soil quality for a very large percentage. soil erosion mainly occurs in the southern part of Flanders, where silty to loamy soils and a hilly topography are responsible for soil loss rates of up to 40 t/ha. Parcels under maize, sugar beet and potatoes are most vulnerable to soil erosion. Crop residues of grain maize and winter wheat followed by catch crops contribute most to the total carbon sequestered in agricultural soils. For the same rotations carbon sequestration is highest on clay soils and lowest on sandy soils. This implies that agricultural policies that impact on agricultural land management influence soil quality for a large percentage. The coupled REGCROP-PESERA-ROTHC model allows for quantifying the impact of seasonal and year-to-year crop growth dynamics on soil quality. When coupled to a multi-annual crop rotation database both spatial and temporal analysis becomes possible and allows for decision support at both farm and regional level. The framework is therefore suited for further scenario analysis and impact assessment. The research is funded by the Belgian Science Policy Organisation (Belspo) under contract nr SD/RI/03A.

Nematode Community Response to Green Infrastructure Design in a Semiarid City.

PubMed

Pavao-Zuckerman, Mitchell A; Sookhdeo, Christine

2017-05-01

Urbanization affects ecosystem function and environmental quality through shifts in ecosystem fluxes that are brought on by features of the built environment. Green infrastructure (GI) has been suggested as a best management practice (BMP) to address urban hydrologic and ecological impacts of the built environment, but GI practice has only been studied from a limited set of climatic conditions and disciplinary approaches. Here, we evaluate GI features in a semiarid city from the perspective of soil ecology through the application of soil nematode community analysis. This study was conducted to investigate soil ecological interactions in small-scale GI as a means of assessing curb-cut rain garden basin design in a semiarid city. We looked at the choice of mulching approaches (organic vs. rock) and how this design choice affects the soil ecology of rain basins in Tucson, AZ. We sampled soils during the monsoon rain season and assessed the soil nematode community as a bioindicator of soil quality and biogeochemical processes. We found that the use of organic mulch in GI basins promotes enhanced soil organic matter contents and larger nematode populations. Nematode community indices point to enhanced food web structure in streetscape rain garden basins that are mulched with organic material. Results from this study suggest that soil management practices for GI can help promote ecological interactions and ecosystem services in urban ecosystems. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Annual fire and mowing alter biomass, depth distribution, and C and N content of roots in soil in tallgrass prairie

Treesearch

D.J. Kitchen; J.M. Blair; M.A. Callaham

2009-01-01

Management practices, such as fire andmowing, can affect the distribution and quality of roots and soil C and N in grasslands. We examined long-term (13 years) effects of annual fire and mowing on fine (<2 mm) roots and soil C and N content in a native tallgrass prairie at Konza Prairie Biological Station in northeastern Kansas, USA. Using 90 cm deep soil cores...

Influence of hydroponic and soil cultivation on quality and shelf life of ready-to-eat lamb's lettuce (Valerianella locusta L. Laterr).

PubMed

Manzocco, Lara; Foschia, Martina; Tomasi, Nicola; Maifreni, Michela; Dalla Costa, Luisa; Marino, Marilena; Cortella, Giovanni; Cesco, Stefano

2011-06-01

Nowadays, there is an increasing interest in the hydroponic floating system to cultivate leafy vegetables for ready-to-eat salads. It is reasonable that different growing systems could affect the quality and shelf life of these salads. The quality and shelf life of ready-to-eat lamb's lettuce grown in protected environment in soil plot or in soil-less system over hydroponic solution with or without the addition of 30 µmol L⁻¹ silicon were evaluated. Minimum effects were observed on colour, firmness and microbial counts. Hydroponic cultivation largely affected plant tissue hydration, leading to weight loss and structural modifications during refrigerated storage. The shelf life of lamb's lettuce was limited by the development of visually detectable unpleasant sensory properties. Shelf life, calculated by survival analysis of consumer acceptability data, resulted about 7 days for soil-cultivated salad and 2 days for the hydroponically grown ones. The addition of silicon to the hydroponic solution resulted in an interesting strategy to increase plant tissue yield and reduce nitrate accumulation. Although hydroponic cultivation may have critical consequences on product quality and shelf life, these disadvantages could be largely counterbalance by increased yield and a reduction of nitrate accumulation when cultivation is performed on nutritive solutions with supplemental addition of silicon. Copyright © 2011 Society of Chemical Industry.

Elevated enzyme activities in soils under the invasive nitrogen-fixing tree Falcataria moluccana

Treesearch

Steven D. Allison; Caroline Nielsen; R. Flint Hughes

2006-01-01

Like other N-fixing invasive species in Hawaii, Falcataria moluccana dramatically alters forest structure, litterfall quality and quantity, and nutrient dynamics. We hypothesized that these biogeochemical changes would also affect the soil microbial community and the extracellular enzymes responsible for carbon and nutrient mineralization. Across...

NITROGEN DEPOSITION AND ORGANIC MATTER MANIPULATIONS AFFECT GROSS AND NET NITROGEN TRANSFORMATIONS IN TWO TEMPERATE FORESTS SOILS

EPA Science Inventory

Soil nitrogen transformations are intricately linked to carbon transformations. We utilized two existing organic matter manipulation sites in western Oregon, USA and Hungary to investigate these linkages. Our questions were: 1) Does the quantity and quality of organic matter af...

Quality of trace element contaminated soils amended with compost under fast growing tree Paulownia fortunei plantation.

PubMed

Madejón, P; Xiong, J; Cabrera, F; Madejón, E

2014-11-01

The use of fast growing trees could be an alternative in trace element contaminated soils to stabilize these elements and improve soil quality. In this study we investigate the effect of Paulownia fortunei growth on trace element contaminated soils amended with two organic composts under semi-field conditions for a period of 18 months. The experiment was carried out in containers filled with tree different soils, two contaminated soils (neutral AZ and acid V) and a non contaminated soil, NC. Three treatments per soil were established: two organic amendments (alperujo compost, AC, and biosolid compost, BC) and a control without amendment addition. We study parameters related with fertility and contamination in soils and plants. Paulownia growth and amendments increased pH in acid soils whereas no effect of these factors was observed in neutral soils. The plant and the amendments also increased organic matter and consequently, soil fertility. Positive results were also found in soils that were only affected by plant growth (without amendment). A general improvement of "soil biochemical quality" was detected over time and treatments, confirming the positive effect of amendments plus paulownia. Even in contaminated soils, except for Cu and Zn, trace element concentrations in leaves were in the normal range for plants. Results of this mid-term study showed that Paulownia fortunei is a promising species for phytoremediation of trace element polluted soils. Copyright © 2014 Elsevier Ltd. All rights reserved.

Canopy management in rainfed vineyards (cv. Tempranillo) for optimising water use and enhancing wine quality.

PubMed

Pascual, Miquel; Romero, María-Paz; Rufat, Josep; Villar, Josep M

2015-12-01

Rainfed viticulture, mainly in semi-arid environments, is limited by environmental variability, particularly precipitation and its seasonal distribution, and soil water availability, thus ultimately determining the final quality of grape and wine. Studies on the feasibility of practices such as canopy management to adapt plant growth and yield to soil water availability open up possibilities to preserve wine quality and reinforce the characteristics of the terroir. Principal components analysis was used to identify the relationships between a large set of variables, including soil, plant, canopy management, and wine characteristics. Canopy management was found to have a predominant influence on plant response to soil water by modifying plant water status, changing the amino acid profile in berries and, concomitantly, altering the sensorial attributes of the wine obtained. Grapevine canopy management strategies, such as reiterate shoot trimming to restrict growth during early phases, are effective in adapting plant response to soil water availability. Such strategies affect berry and wine quality, mainly the amino acid profile and sensorial attributes of the wine, without changing yield or grape harvest quality control parameters. Also, in such conditions, nitrogen does not make a significant contribution to grapevine growth or yield or to grape quality. © 2015 Society of Chemical Industry.

Soil Physicochemical and Biological Properties of Paddy-Upland Rotation: A Review

PubMed Central

Lv, Teng-Fei; Chen, Yong; Westby, Anthony P.; Ren, Wan-Jun

2014-01-01

Paddy-upland rotation is an unavoidable cropping system for Asia to meet the increasing demand for food. The reduction in grain yields has increased the research interest on the soil properties of rice-based cropping systems. Paddy-upland rotation fields are unique from other wetland or upland soils, because they are associated with frequent cycling between wetting and drying under anaerobic and aerobic conditions; such rotations affect the soil C and N cycles, make the chemical speciation and biological effectiveness of soil nutrient elements varied with seasons, increase the diversity of soil organisms, and make the soil physical properties more difficult to analyze. Consequently, maintaining or improving soil quality at a desirable level has become a complicated issue. Therefore, fully understanding the soil characteristics of paddy-upland rotation is necessary for the sustainable development of the system. In this paper, we offer helpful insight into the effect of rice-upland combinations on the soil chemical, physical, and biological properties, which could provide guidance for reasonable cultivation management measures and contribute to the improvement of soil quality and crop yield. PMID:24995366

[Quality level assessment of lowly efficient Tamarix chinensis secondary shrubs in Laizhou Bay of Yellow River Delta].

PubMed

Xia, Jiang-Bao; Liu, Yu-Ting; Zhu, Jin-Fang; Xu, Jing-Wei; Lu, Zhao-Hua; Liu, Jing-Tao; Liu, Qing

2013-06-01

Taking the Tamarix chinensis secondary shrubs in Laizhou Bay of Yellow River Delta as test objects, and by using synthetic factor method, this paper studied the main factors causing the lowly efficiency of T. chinensis secondary shrubs as well as the main parameters for the classification of lowly efficient T. chinensis secondary shrubs. A total of 24 indices including shrubs growth and soil physical and chemical properties were selected to determine the main affecting factors and parameters in evaluating and classifying the lowly efficient shrubs. There were no obvious correlations between the indices reflecting the shrubs growth and soil quality, and thus, only using shrub growth index to reflect the lowly efficiency level of T. chinensis was not enough, and it would be necessary to combine with soil quality factors to make a comprehensive evaluation. The principal factors reflecting the quality level of lowly efficient T. chinensis shrubs included soil salt content and moisture content, stand age, single tree's aboveground stem, leaf biomass, and basal diameter, followed by soil density, porosity, and soil nutrient status. The lowly efficient T. chinensis shrubs in the Bay could be classified into five types, namely, shrub with growth potential, slightly low quality shrub, moderately lowly efficient shrub, moderately low quality and lowly efficient shrub, and seriously low quality and lowly efficient shrub. The main features, low efficiency causes, and management measures of these shrubs were discussed based on the mean cluster value.

Consequences of using different soil texture determination methodologies for soil physical quality and unsaturated zone time lag estimates

NASA Astrophysics Data System (ADS)

Fenton, O.; Vero, S.; Ibrahim, T. G.; Murphy, P. N. C.; Sherriff, S. C.; Ó hUallacháin, D.

2015-11-01

Elucidation of when the loss of pollutants, below the rooting zone in agricultural landscapes, affects water quality is important when assessing the efficacy of mitigation measures. Investigation of this inherent time lag (tT) is divided into unsaturated (tu) and saturated (ts) components. The duration of these components relative to each other differs depending on soil characteristics and the landscape position. The present field study focuses on tu estimation in a scenario where the saturated zone is likely to constitute a higher proportion of tT. In such instances, or where only initial breakthrough (IBT) or centre of mass (COM) is of interest, utilisation of site and depth specific "simple" textural class or actual sand-silt-clay percentages to generate soil water characteristic curves with associated soil hydraulic parameters is acceptable. With the same data it is also possible to estimate a soil physical quality (S) parameter for each soil layer which can be used to infer many other physical, chemical and biological quality indicators. In this study, hand texturing in the field was used to determine textural classes of a soil profile. Laboratory methods, including hydrometer, pipette and laser diffraction methods were used to determine actual sand-silt-clay percentages of sections of the same soil profile. Results showed that in terms of S, hand texturing resulted in a lower index value (inferring a degraded soil) than that of pipette, hydrometer and laser equivalents. There was no difference between S index values determined using the pipette, hydrometer and laser diffraction methods. The difference between the three laboratory methods on both the IBT and COM stages of tu were negligible, and in this instance were unlikely to affect either groundwater monitoring decisions, or to be of consequence from a policy perspective. When tu estimates are made over the full depth of the vadose zone, which may extend to several metres, errors resulting from the use of hydraulic parameters generated from hand texture data will be resultantly greater, and may lead to flawed predictions regarding the achievability of water policy targets. For this reason laboratory analysis, regardless of method, should be preferred to simple field assessments.

Litter quality mediated nitrogen effect on plant litter decomposition regardless of soil fauna presence.

PubMed

Zhang, Weidong; Chao, Lin; Yang, Qingpeng; Wang, Qingkui; Fang, Yunting; Wang, Silong

2016-10-01

Nitrogen addition has been shown to affect plant litter decomposition in terrestrial ecosystems. The way that nitrogen deposition impacts the relationship between plant litter decomposition and altered soil nitrogen availability is unclear, however. This study examined 18 co-occurring litter types in a subtropical forest in China in terms of their decomposition (1 yr of exposure in the field) with nitrogen addition treatment (0, 0.4, 1.6, and 4.0 mol·N·m -2 ·yr -1 ) and soil fauna exclusion (litter bags with 0.1 and 2 cm mesh size). Results showed that the plant litter decomposition rate is significantly reduced because of nitrogen addition; the strength of the nitrogen addition effect is closely related to the nitrogen addition levels. Plant litters with diverse quality responded to nitrogen addition differently. When soil fauna was present, the nitrogen addition effect on medium-quality or high-quality plant litter decomposition rate was -26% ± 5% and -29% ± 4%, respectively; these values are significantly higher than that of low-quality plant litter decomposition. The pattern is similar when soil fauna is absent. In general, the plant litter decomposition rate is decreased by soil fauna exclusion; an average inhibition of -17% ± 1.5% was exhibited across nitrogen addition treatment and litter quality groups. However, this effect is weakly related to nitrogen addition treatment and plant litter quality. We conclude that the variations in plant litter quality, nitrogen deposition, and soil fauna are important factors of decomposition and nutrient cycling in a subtropical forest ecosystem. © 2016 by the Ecological Society of America.

Fire impact and assessment of post-fire actions of a typical Mediterranean forest from SW Spain

NASA Astrophysics Data System (ADS)

Jiménez-González, Marco A.; María De la Rosa, José; Jiménez-Morillo, Nicasio T.; Zavala, Lorena M.; Knicker, Heike

2015-04-01

Wildfires may cause significant changes in soil physical and chemical properties. In addition, soil organic matter (SOM) content and chemical properties are usually affected by fire. Fire impacts may negatively affect soil health and quality, and induce or enhance runoff generation and, thereby, soil erosion risk and cause damages to the habitat of species. This fact is especially dramatic in Mediterranean ecosystems, where forest fires are a frequent phenomenon and restoration strategies are a key issue. The goals of this study are to determine: i) the immediate effects of fire on soil properties, including changes occurred in the quantity and quality of SOM and ii) the effect of post-fire actions on soil properties. In August 2012, a wildfire affected a forest area of approx. 90 ha in Montellano (Seville, SW Spain; longitude 37.00 °, latitude -5.56 °). This area is dominated by pines (Pinus pinaster and Pinus halepensis), and eucalypts (Eucaliptus globulus) with a Mediterranean climate. Dominant soil types are Rendzic Leptosols and Calcaric Haplic Regosols. It is a poorly limestone-developed soil (usually swallower than 25 cm). Four soil subsamples were collected 1 month and 25 months after fire within an area of approximately 200 m2. Subsamples were mixed together, homogenized, air-dried, crushed and sieved (2 mm). One control sample was collected in an adjacent area. The litter layer was removed by hand and studied separately. Branches, stems, bushes and plant residues on the fire-affected area were removed 16 months after the fire using heavy machinery as part of the post-fire management. The present research focuses on the study of the elemental composition (C, H and N) and physical properties (pH, water holding capacity, electrical conductivity) of bulk soil samples, and on the spectroscopic analysis (FT-IR, 13C NMR) and analytical pyrolysis data obtained from bulk the oils and from the humic acid fraction. immediate effects of fire, including the charring of vegetation and litter, as the input of charred residues may contribute to increase the total amount of soil organic matter. The post-fire removal of vegetation probably contributed to an additional loss of soil material due to an increase of the erosion risk. In addition, preliminary results point out that the burnt soil is not being recovered to the pre-fire conditions at a molecular level neither in the elemental composition. Results of this study will constitute a valuable tool for stake holders and decision makers to avoid additional alterations caused by post fire management of fire affected forests.

Terroir et vignoble: how the farming management can affect the production of a quality wine

NASA Astrophysics Data System (ADS)

Gallo, Alba; Bini, Claudio

2016-04-01

Italian wine is one of the most exported wine in the world. The particular climate, the soil characteristics and other several factors have contributed to this success. Italy is located in the temperate belt, with a suitable climate for grapevine cultivation. For this reason, all regions in Italy produce wine, first of all the Veneto region, with 8.569.000 hl of wine in 2011. Wine quality derives from the perfect interaction among climate, morphology, soil and plant, i.e. the terroir. So, knowledge of the land characteristics, together with cultivation techniques and management, is essential to understand this interaction and the typicality of the wine. For example, large utilization of fertilizers and pesticides may determine accumulation of toxic substances in soil and possible translocation to the food chain. For this reason, metal contamination of soils and plants becomes a main issue in agricultural production. Therefore, our attention was focused on the determination of soil quality of the Prosecco DOCG (controlled and guaranteed denomination of origin) area, particularly in Conegliano. Conegliano is a town located in Veneto, in the province of Treviso, known for its wine. This wine variety is regulated by the Conegliano-Valdobbiadene production Consortium, to protect both consumers and producers. The goals of this research are: evaluation of trace metal content (Al ,Cd, Cr, Cu, Fe, Mg, Mn, Ni, P, Pb, V and Zn) in soils and possible uptake by grape leaves; estimation of biological soil quality (QBS-ar index); analysis of oxidative stress in dandelion (Taraxacum officinale) and grape leaves, by the Lipid peroxidation test (LPO test). Results concerning trace metal concentration show: i) a high content of Al, Mg and P in soils, and ii) high concentration of Al, Cu, Fe and Zn in grape leaves. High contents of Al in topsoil are consistent with the high concentration of organic matter. Instead, high Al contents in subsoil are related to clay. Mg and P are usually added to soil as fertilizer. In grape leaves, Al concentration is releated to Al content in soil, Cu could derive from foliar fungicides and no signs of toxicity from high content of Fe and Zn are visible. LPO test values are below the reference value, therefore vegetation in the study area is not affected by oxidative stress. Concerning the biological soil quality, 3 different classes (4, 5 and 6) were recorded (with noteworthy microarthropods adaption to soil conditions. This result suggest that the study area presents good grade ecosystem stability and limited stress evident. In conclusion, it is possible to assert that the study area is characterized by not polluted soils of good quality and without environmental stress. It is likely that the agronomic practices do not produce any negative effect on plant growth and, thus, on quality of wine.

Exploring the potential offered by legacy soil databases for ecosystem services mapping of Central African soils

NASA Astrophysics Data System (ADS)

Verdoodt, Ann; Baert, Geert; Van Ranst, Eric

2014-05-01

Central African soil resources are characterised by a large variability, ranging from stony, shallow or sandy soils with poor life-sustaining capabilities to highly weathered soils that recycle and support large amounts of biomass. Socio-economic drivers within this largely rural region foster inappropriate land use and management, threaten soil quality and finally culminate into a declining soil productivity and increasing food insecurity. For the development of sustainable land use strategies targeting development planning and natural hazard mitigation, decision makers often rely on legacy soil maps and soil profile databases. Recent development cooperation financed projects led to the design of soil information systems for Rwanda, D.R. Congo, and (ongoing) Burundi. A major challenge is to exploit these existing soil databases and convert them into soil inference systems through an optimal combination of digital soil mapping techniques, land evaluation tools, and biogeochemical models. This presentation aims at (1) highlighting some key characteristics of typical Central African soils, (2) assessing the positional, geographic and semantic quality of the soil information systems, and (3) revealing its potential impacts on the use of these datasets for thematic mapping of soil ecosystem services (e.g. organic carbon storage, pH buffering capacity). Soil map quality is assessed considering positional and semantic quality, as well as geographic completeness. Descriptive statistics, decision tree classification and linear regression techniques are used to mine the soil profile databases. Geo-matching as well as class-matching approaches are considered when developing thematic maps. Variability in inherent as well as dynamic soil properties within the soil taxonomic units is highlighted. It is hypothesized that within-unit variation in soil properties highly affects the use and interpretation of thematic maps for ecosystem services mapping. Results will mainly be based on analyses done in Rwanda, but can be complemented with ongoing research results or prospects for Burundi.

Response of soil physico-chemical properties to restoration approaches and submergence in the water level fluctuation zone of the Danjiangkou Reservoir, China.

PubMed

Shu, Xiao; Zhang, KeRong; Zhang, QuanFa; Wang, WeiBo

2017-11-01

With the completion of the Danjiangkou Dam, the impoundment and drainage of dams can significantly alter shorelines, hydrological regime, and sediment and can result in the loss of soil and original riparian vegetation. Revegetation may affect soil properties and have broad important implications both for ecological services and soil recovery. In this work, we investigated the soil properties under different restoration approaches, and before and after submergence in the water level fluctuation zone (WLFZ) of the Danjiangkou Reservoir. Soil physical (bulk density and soil moisture), chemical (pH, soil organic carbon, nitrogen, phosphorus and potassium contents), and heavy metals were determined. This study reported that restoration approaches have impacts on soil moisture, pH, N, soil organic carbon, P, K and heavy metals in the WLFZ of the Danjiangkou Reservoir. Our results indicated that different restoration approaches could increase the soil moisture while decrease soil pH. Higher soil organic carbon in propagule banks transplantation (PBT) and shrubs restoration (SR) indicate that PBT and SR may provide soil organic matter more quickly than trees restoration (TR). SR and TR could significantly improve the soil total P and available P. PBT and SR could improve the soil total K and available K. SR and TR could significantly promote Cu and Zn adsorption, and Pb and Fe release by plant. Submergence could significantly affect the soil pH, NO 3 － -N, NH 4 ＋ -N, total P and available P. Submergence could promote NO 3 － -N and available P adsorption, and NH 4 ＋ -N and total P release by soil. The soil quality index (SQI) values implied that TR and PBT greatly improved soil quality. The present study suggests that PBT and TR could be effective for soil restoration in WLFZ of the Danjiangkou Reservoir. Copyright © 2017 Elsevier Inc. All rights reserved.

Case study of microarthropod communities to assess soil quality in different managed vineyards

NASA Astrophysics Data System (ADS)

Gagnarli, E.; Goggioli, D.; Tarchi, F.; Guidi, S.; Nannelli, R.; Vignozzi, N.; Valboa, G.; Lottero, M. R.; Corino, L.; Simoni, S.

2015-07-01

Land use influences the abundance and diversity of soil arthropods. The evaluation of the impact of different management strategies on soil quality is increasingly sought, and the determination of community structures of edaphic fauna can represent an efficient tool. In the area of Langhe (Piedmont, Italy), eight vineyards characterized for physical and chemical properties (soil texture, soil pH, total organic carbon, total nitrogen, calcium carbonate) were selected. We evaluated the effect of two types of crop management, organic and integrated pest management (IPM), on abundance and biodiversity of microarthropods living at the soil surface. Soil sampling was carried out in winter 2011 and spring 2012. All specimens were counted and determined up to the order level. The biodiversity analysis was performed using ecological indexes (taxa richness, dominance, Shannon-Wiener, Buzas and Gibson's evenness, Margalef, equitability, Berger-Parker), and the biological soil quality was assessed with the BSQ-ar index. The mesofauna abundance was affected by both the type of management and sampling time. On the whole, a higher abundance was in organic vineyards (N = 1981) than in IPM ones (N = 1062). The analysis performed by ecological indexes showed quite a high level of biodiversity in this environment, particularly in May 2012. Furthermore, the BSQ-ar values registered were similar to those obtained in preserved soils.

Performance of rose scented geranium (Pelargonium graveolens) in heavy metal polluted soil vis-à-vis phytoaccumulation of metals.

PubMed

Chand, Sukhmal; Singh, Geetu; Patra, D D

2016-08-02

An investigation was carried out to evaluate the effect of heavy metal toxicity on growth, herb, oil yield and quality and metal accumulation in rose scented geranium (Pelargonium graveolens) grown in heavy metal enriched soils. Four heavy metals (Cd, Ni, Cr, and Pb) each at two levels (10 and 20 mg kg-1 soil) were tested on geranium. Results indicated that Cr concentration in soil at 20 mg kg-1 reduced leaves, stem and root yield by 70, 83, and 45%, respectively, over control. Root growth was significantly affected in Cr stressed soil. Nickel, Cr, and Cd concentration and accumulation in plant increased with higher application of these metals. Chromium, nickel and cadmium uptake was observed to be higher in leaves than in stem and roots. Essential oil constituents were generally not significantly affected by heavy metals except Pb at 10 and 20 ppm, which significantly increased the content of citronellol and Ni at 20 ppm increased the content of geraniol. Looking in to the higher accumulation of toxic metals by geranium and the minimal impact of heavy metals on quality of essential oil, geranium can be commercially cultivated in heavy metal polluted soil for production of high value essential oil.

Fungal-to-bacterial dominance of soil detrital food-webs: Consequences for biogeochemistry

NASA Astrophysics Data System (ADS)

Rousk, Johannes; Frey, Serita

2015-04-01

Resolving fungal and bacterial groups within the microbial decomposer community is thought to capture disparate microbial life strategies, associating bacteria with an r-selected strategy for carbon (C) and nutrient use, and fungi with a K-selected strategy. Additionally, food-web models have established a widely held belief that the bacterial decomposer pathway in soil supports high turnover rates of easily available substrates, while the slower fungal pathway supports the decomposition of more complex organic material, thus characterising the biogeochemistry of the ecosystem. Three field-experiments to generate gradients of SOC-quality were assessed. (1) the Detritus Input, Removal, and Trenching - DIRT - experiment in a temperate forest in mixed hardwood stands at Harvard Forest LTER, US. There, experimentally adjusted litter input and root input had affected the SOC quality during 23 years. (2) field-application of 14-C labelled glucose to grassland soils, sampled over the course of 13 months to generate an age-gradient of SOM (1 day - 13 months). (3) The Park Grass Experiment at Rothamsted, UK, where 150-years continuous N-fertilisation (0, 50, 100, 150 kg N ha-1 y-1) has affected the quality of SOM in grassland soils. A combination of carbon stable and radio isotope studies, fungal and bacterial growth and biomass measurements, and C and N mineralisation (15N pool dilution) assays were used to investigate how SOC-quality influenced fungal and bacterial food-web pathways and the implications this had for C and nutrient turnover. There was no support that decomposer food-webs dominated by bacteria support high turnover rates of easily available substrates, while slower fungal-dominated decomposition pathways support the decomposition of more complex organic material. Rather, an association between high quality SOC and fungi emerges from the results. This suggests that we need to revise our basic understanding for soil microbial communities and the processes they regulate in soil.

Effects of coal-bed methane discharge waters on the vegetation and soil ecosystem in Powder River Basin, Wyoming

USGS Publications Warehouse

Stearns, M.; Tindall, J.A.; Cronin, G.; Friedel, M.J.; Bergquist, E.

2005-01-01

Coal-bed methane (CBM) co-produced discharge waters in the Powder River Basin of Wyoming, resulting from extraction of methane from coal seams, have become a priority for chemical, hydrological and biological research during the last few years. Soil and vegetation samples were taken from affected and reference sites (upland elevations and wetted gully) in Juniper Draw to investigate the effects of CBM discharge waters on soil physical and chemical properties and on native and introduced vegetation density and diversity. Results indicate an increase of salinity and sodicity within local soil ecosystems at sites directly exposed to CBM discharge waters. Elevated concentrations of sodium in the soil are correlated with consistent exposure to CBM waters. Clay-loam soils in the study area have a much larger specific surface area than the sandy soils and facilitate a greater sodium adsorption. However, there was no significant relation between increasing water sodium adsorption ratio (SAR) values and increasing sediment SAR values downstream; however, soils exposed to the CBM water ranged from the moderate to severe SAR hazard index. Native vegetation species density was highest at the reference (upland and gully) and CBM affected upland sites. The affected gully had the greatest percent composition of introduced vegetation species. Salt-tolerant species had the greatest richness at the affected gully, implying a potential threat of invasion and competition to established native vegetation. These findings suggest that CBM waters could affect agricultural production operations and long-term water quality. ?? Springer 2005.

Water-quality assessment of the lower Illinois River Basin; environmental setting

USGS Publications Warehouse

Warner, Kelly L.

1998-01-01

The lower Illinois River Basin (LIRB) encompasses 18,000 square miles of central and western Illinois. Historical and recent information from Federal, State, and local agencies describing the physiography, population, land use, soils, climate, geology, streamflow, habitat, ground water, water use, and aquatic biology is summarized to describe the environmental setting of the LIRB. The LIRB is in the Till Plains Section of the Central Lowland physiographic province. The basin is characterized by flat topography, which is dissected by the Illinois River. The drainage pattern of the LIRB has been shaped by many bedrock and glacial geologic processes. Erosion prior to and during Pleistocene time created wide and deep bedrock valleys. The thickest deposits and most major aquifers are in buried bedrock valleys. The Wisconsinan glaciation, which bisects the northern half of the LIRB, affects the distribution and characteristics of glacial deposits in the basin. Agriculture is the largest land use and forested land is the second largest land use in the LIRB. The major urban areas are near Peoria, Springfield, Decatur, and Bloomington-Normal. Soil type and distribution affect the amount of soil erosion, which results in sedimentation of lakes and reservoirs in the basin. Rates of soil erosion of up to 2 percent per year of farmland soil have been measured. Many of the 300 reservoirs, lakes, and wetlands are disappearing because of sedimentation resulting from agriculture activities, levee building, and urbanization. Sedimentation and the destruction of habitat appreciably affect the ecosystem. The Illinois River is a large river-floodplain ecosystem where biological productivity is enhanced by annual flood pulses that advance and retreat over the flood plain and temporarily expand backwater and flood-plain lakes. Ground-water discharge to streams affects the flow and water quality of the streams. The water budget of several subbasins show variability in ground-water contribution from runoff and storage. More than half of the drinking water, including domestic and public-supply use, in the LIRB is from ground water. Fifty-two percent of the public-supply water is from surface water. Ground-water withdrawals mostly are from glacial sand and gravel aquifers. Structural features, such as monoclines, synclines, and anticlines, in the buried bedrock affect the water quality of the aquifers. There are five natural environmental divisions in the LIRB. The Grand Prairie covers most of the northeastern half of the basin, and the Western Forest-Prairie covers most of the southwestern half. Implications of environmental setting for water quality in the LIRB are related primarily to land use. The balanced fish community indicates that the lower Illinois River is affected less from urban and industrial waste than the upper Illinois River. A decrease in dissolved oxygen concentrations and turbidity in the lower reaches of the basin in 1993 have resulted from the recent influx of European zebra mussels to the LIRB. Many factors affect water quality in the LIRB. Bedrock and surface topography, type of glacial material, and land use most directly affect water quality in the basin.

Undisturbed soil columns for lysimetry II. Miscible displacement and field evaluation

USDA-ARS?s Scientific Manuscript database

Concerns about agriculture's effect on water quality and the expanding use of no-tillage, has produced a crucial need for in situ solute transport research of mobile nutrients as affected by tillage system. Eight undisturbed soil columns (41 cm diameter by 100 cm long) were sealed into PVC cylinder...

Factors affecting ground-water quality in Oakland County, Michigan

USGS Publications Warehouse

,

2004-01-01

Ground water is water stored in pores within soil and rock beneath the land surface. When these pores are connected so that water can be transmitted to wells or springs, these bodies of soil and rock are termed aquifers, from two Greek words meaning “water” and “to bear.” 

Microbial and physical properties as indicators of sandy soil quality under cropland and grassland

NASA Astrophysics Data System (ADS)

Frac, Magdalena; Lipiec, Jerzy; Usowicz, Boguslaw; Oszust, Karolina; Brzezinska, Malgorzata

2017-04-01

Land use is one of the key factor driving changes in soil properties influencing on soil health and quality. Microbial diversity and physical properties are sensitive indicators for assessing soil health and quality. The alterations of microbial diversity and physical properties following land use changes have not been sufficiently elucidated, especially for sandy soils. We investigated microbial diversity indicators including fungal communities composition and physical properties of sandy acid soil under cropland and more than 20-yr-old grassland (after cropland) in Trzebieszów, Podlasie Region, Poland (N 51° 59' 24", E 22° 33' 37"). The study included four depths within 0-60 cm. Microbial genetic diversity was assessed by terminal restriction fragment length polymorphism (t-RFLP) analysis, fungal community composition was evaluated by next generation sequencing (NGS) analysis and functional diversity was determined by Biolog EcoPlate method. Overall microbial activity was assessed by soil enzymes (dehydrogenases, β-glucosidase) and respiration test. At the same places soil texture, organic carbon content, pH, bulk density, water holding capacity were determined. Our results showed that grassland soil was characterized by higher activity of soil enzymes than cropland. The average well color development of soil microorganisms, the microbial functional diversity and the number of carbon source utilization were significantly affected by land use type and were differentiated among soil depths. In grassland compared to cropland soil a significant increase of carboxylic acids and decrease of amino acids utilization was observed. The quantitative and qualitative differences were found in community of ammonia oxidizing archaea in cropland and grassland soil. The results of fungal community composition help to explain the soil health of grassland and cropland based on the appearance of phytopathogenic and antagonistic fungi. In general bulk density and field water capacity were greater and saturated hydraulic conductivity was lower under grassland than cropland soil. The study was funded by HORIZON 2020, European Commission, Programme: H2020-SFS-4-2014: Soil quality and function, project No. 635750, Interactive Soil Quality Assessment in Europe and China for Agricultural Productivity and Environmental Resilience (iSQAPER, 2015-2020).

[Identification of using organic carbon isotopic composition of soil pollution process].

PubMed

Guo, Qing-Jun; Chen, Tong-Bin; Yang, Jun; Strauss, Harald; Lei, Mei; Zhu, Guang-Xu; Li, Yan-Mei; Zhou, Xiao-Yong; Li, Xiao-Yan

2011-10-01

This study has taken advantage of the characteristics of concentration of soil organic matter (SOC) and delta13 C(SOC) values to provide proofs for environment quality assessment and to know more about polluted sources, sizes and processes in Beijing steel company area. delta13C values of SOC is good for tracing sources and documenting shifts in community composition and distribution. Two sections (Beijing steel company area and Yongledian, Tongzhou) which belong to two different soil types collected in Beijing, and organic carbon isotopic composition and total soil organic carbon were analyzed. These results shows that SOC of soil samples from Beijing steel company area are quite high, and even 9.7% at the surface sample, however SOC from unpolluted area (Yongledian area) is lower than those of industrial area. delta13 C(SOC) from soils of Beijing steel company area and Yongledian area respectively vary from -24.8 per thousand to -23.1 per thousand and -26.4 per thousand to -20.5 per thousand, the results are quite different. The results reflect that there are different organic carbon sources in different types' soil: Organic carbon from Beijing steel company area has been mainly affected by coal burning, soil organic carbon concentrations are quite high, and pollution can affect on soils 70 cm deep underground; and soils from Yongledian area, have been not polluted, and organic matter is from natural litter (C3 plants). Although there are different soil organic carbon concentrations and isotope compositions, two soil sections have similar variation trends. This study provides proofs for environment quality assessment and know more about polluted and natural sources, sizes in Beijing.

Deep soil carbon dynamics are driven more by soil type than by climate: a worldwide meta-analysis of radiocarbon profiles.

PubMed

Mathieu, Jordane A; Hatté, Christine; Balesdent, Jérôme; Parent, Éric

2015-11-01

The response of soil carbon dynamics to climate and land-use change will affect both the future climate and the quality of ecosystems. Deep soil carbon (>20 cm) is the primary component of the soil carbon pool, but the dynamics of deep soil carbon remain poorly understood. Therefore, radiocarbon activity (Δ14C), which is a function of the age of carbon, may help to understand the rates of soil carbon biodegradation and stabilization. We analyzed the published 14C contents in 122 profiles of mineral soil that were well distributed in most of the large world biomes, except for the boreal zone. With a multivariate extension of a linear mixed-effects model whose inference was based on the parallel combination of two algorithms, the expectation-maximization (EM) and the Metropolis-Hasting algorithms, we expressed soil Δ14C profiles as a four-parameter function of depth. The four-parameter model produced insightful predictions of soil Δ14C as dependent on depth, soil type, climate, vegetation, land-use and date of sampling (R2=0.68). Further analysis with the model showed that the age of topsoil carbon was primarily affected by climate and cultivation. By contrast, the age of deep soil carbon was affected more by soil taxa than by climate and thus illustrated the strong dependence of soil carbon dynamics on other pedologic traits such as clay content and mineralogy. © 2015 John Wiley & Sons Ltd.

Rare earth element transfer from soil to navel orange pulp (Citrus sinensis Osbeck cv. Newhall) and the effects on internal fruit quality.

PubMed

Cheng, Jinjin; Ding, Changfeng; Li, Xiaogang; Zhang, Taolin; Wang, Xingxiang

2015-01-01

The effects of soil rare earth element (REE) on navel orange quality and safety in rare earth ore areas have gained great attention. This study investigated the transfer characteristics of REE from soil to navel orange pulp (Citrus sinensis Osbeck cv. Newhall) and examined the effects of soil REE on internal fruit quality in Xinfeng County, Jiangxi province, China. Path analysis showed that soil REE, pH, cation exchange capacity (CEC), and Fe oxide (Feox) significantly affected pulp REE concentrations. A Freundlich-type prediction model for pulp REE was established: log[REEpulp] = -1.036 + 0.272 log[REEsoil] - 0.056 pH - 0.360 log[CEC] + 0.370 log[Feox] (n = 114, R2 = 0.60). From the prediction model, it was inferred that even when soil REE and Feox were as high as 1038 mg kg-1 and 96.4 g kg-1, respectively, and pH and CEC were as low as 3.75 and 5.08 cmol kg-1, respectively, pulp REE concentrations were much lower than the food limit standard. Additionally, soil REE levels were significantly correlated with selected fruit quality indicators, including titratable acidity (r = 0.52, P < 0.01), total soluble solids (r = 0.48, P < 0.01) and vitamin C (r = 0.56, P < 0.01). Generally, under routine methods of water and fertilization management, the cultivation of navel oranges in rare earth ore areas of south China with soil REE ranging from 38.6 to 546 mg kg-1 had improved in internal fruit quality.

Rare Earth Element Transfer from Soil to Navel Orange Pulp (Citrus sinensis Osbeck cv. Newhall) and the Effects on Internal Fruit Quality

PubMed Central

Cheng, Jinjin; Ding, Changfeng; Li, Xiaogang; Zhang, Taolin; Wang, Xingxiang

2015-01-01

The effects of soil rare earth element (REE) on navel orange quality and safety in rare earth ore areas have gained great attention. This study investigated the transfer characteristics of REE from soil to navel orange pulp (Citrus sinensis Osbeck cv. Newhall) and examined the effects of soil REE on internal fruit quality in Xinfeng County, Jiangxi province, China. Path analysis showed that soil REE, pH, cation exchange capacity (CEC), and Fe oxide (Feox) significantly affected pulp REE concentrations. A Freundlich-type prediction model for pulp REE was established: log[REEpulp] = -1.036 + 0.272 log[REEsoil] - 0.056 pH - 0.360 log[CEC] + 0.370 log[Feox] (n = 114, R2 = 0.60). From the prediction model, it was inferred that even when soil REE and Feox were as high as 1038 mg kg-1 and 96.4 g kg-1, respectively, and pH and CEC were as low as 3.75 and 5.08 cmol kg-1, respectively, pulp REE concentrations were much lower than the food limit standard. Additionally, soil REE levels were significantly correlated with selected fruit quality indicators, including titratable acidity (r = 0.52, P < 0.01), total soluble solids (r = 0.48, P < 0.01) and vitamin C (r = 0.56, P < 0.01). Generally, under routine methods of water and fertilization management, the cultivation of navel oranges in rare earth ore areas of south China with soil REE ranging from 38.6 to 546 mg kg-1 had improved in internal fruit quality. PMID:25806821

Spatial Pattern of Soil Salinity in Area Around the Yellow River Delta and Its Seasonal Dynamics over a 3-year Period

NASA Astrophysics Data System (ADS)

Lai, J.; Ouyang, Z.

2017-12-01

Salt-affected land varies spatially and seasonally in terms of soil salinity. "Bohai Granary" is a newly proposed national-level program which was aimed to improve soil quality and mining grain production potential of the salt-affected land in east China. In this work, soil samples were monthly taken at 11 sites within Wudi county in the Yellow river delta. The spatial distribution pattern of soil salinity were investigated and its seasonal variation over 36 months were discussed. Our findings indicate that the vertical distribution type of soil salinity was bottom-accumulating in the near coastal area while its gradually turned into a type of surface-accumulating as the sampling site moving towards the inner land. The peak of the soil salinity along the soil profile alternately moved upwards and downwards during the growing seasons. However, there was no evidence for the increasing of the total salt amount within the upper 100cm of soil. Moreover, the salt was mostly accumulated in the upper soil (0-40cm) during the late spring and early summer season; and winter wheat was tend to be affected severely at this stage. Therefore, special field practices (e.g. regular irrigation to leach salt, good maintenance of drainage system) should be taken to minimize the threat of soil salinity.

The influence of organic amendment and nickel pollution on tomato fruit yield and quality.

PubMed

Palacios, G; Carbonell-Barrachina, A; Gómez, I; Mataix, J

1999-01-01

The effects of organic fertilization (sludge application) and/or different levels of Ni pollution on tomato fruit yield, quality, nutrition, and Ni accumulation were investigated. The mass loading of sewage sludge solids used in this study for the amendment of a calcareous soil with low organic matter content was 2% (w/w). A control with no sewage sludge amendment was also included (S). Nickel was added to the sludge amended soil at 0, 60, 120 and 240 mg kg-1 concentrations. Sewage sludge addition to the calcareous soil significantly increased fruit yield but did not adversely affect the quality and nutritional status of the tomato fruit. The results demonstrated that sewage sludge could be successfully used as a horticultural fertilizer. Only the highest addition rate of Ni (240 mg kg-1) to an organic amended calcareous soil had negative effects on fruit yield and quality, and caused a Ni accumulation in fruit that could be considered as a hazard for human health. Thus, no toxic problems will be encountered in tomato fruit due to Ni pollution provided the total Ni (soil Ni plus Ni incorporated with sludge amendment) concentration is kept below the maximum concentration of Ni allowed for agricultural alkaline soils in Spain (112 mg Ni kg-1).

No tillage combined with crop rotation improves soil microbial community composition and metabolic activity.

PubMed

Sun, Bingjie; Jia, Shuxia; Zhang, Shixiu; McLaughlin, Neil B; Liang, Aizhen; Chen, Xuewen; Liu, Siyi; Zhang, Xiaoping

2016-04-01

Soil microbial community can vary with different agricultural managements, which in turn can affect soil quality. The objective of this work was to evaluate the effects of long-term tillage practice (no tillage (NT) and conventional tillage (CT)) and crop rotation (maize-soybean (MS) rotation and monoculture maize (MM)) on soil microbial community composition and metabolic capacity in different soil layers. Long-term NT increased the soil organic carbon (SOC) and total nitrogen (TN) mainly at the 0-5 cm depth which was accompanied with a greater microbial abundance. The greater fungi-to-bacteria (F/B) ratio was found in NTMS at the 0-5 cm depth. Both tillage and crop rotation had a significant effect on the metabolic activity, with the greatest average well color development (AWCD) value in NTMS soil at all three soil depths. Redundancy analysis (RDA) showed that the shift in microbial community composition was accompanied with the changes in capacity of utilizing different carbon substrates. Therefore, no tillage combined with crop rotation could improve soil biological quality and make agricultural systems more sustainable.

Deforestation effects on soil quality and water retention curve parameters in eastern Ardabil, Iran

NASA Astrophysics Data System (ADS)

Asghari, Sh.; Ahmadnejad, S.; Keivan Behjou, F.

2016-03-01

The land use change from natural to managed ecosystems causes serious soil degradation. The main objective of this research was to assess deforestation effects on soil physical quality attributes and soil water retention curve (SWRC) parameters in the Fandoghlou region of Ardabil province, Iran. Totally 36 surface and subsurface soil samples were taken and soil water contents measured at 13 suctions. Alfa (α) and n parameters in van Genuchten (1980) model were estimated by fitting SWRC data by using RETC software. The slope of SWRC at inflection point (SP) was calculated by Dexter (2004) equation. The results indicated that with changing land use from forest (F) to range land (R) and cultivated land (C), and also with increasing soil depth from 0-25 to 75-100 cm in each land use, organic carbon, micropores, saturated and available water contents decreased and macropores and bulk density increased significantly ( P < 0.05). The position of SWRC shape in F was higher than R and C lands at all soil depths. Changing F to R and C lands and also increasing soil depth in each land use significantly ( P < 0.05) increased α and decreased n and SP. The average values of SP were obtained 0.093, 0.051 and 0.031 for F, R and C, respectively. As a result, deforestation reduced soil physical quality by affecting SWRC parameters.

Soil microbial properties after long-term swine slurry application to conventional and no-tillage systems in Brazil.

PubMed

Balota, Elcio L; Machineski, Oswaldo; Hamid, Karima I A; Yada, Ines F U; Barbosa, Graziela M C; Nakatani, Andre S; Coyne, Mark S

2014-08-15

Swine waste can be used as an agricultural fertilizer, but large amounts may accumulate excess nutrients in soil or contaminate the surrounding environment. This study evaluated long-term soil amendment (15 years) with different levels of swine slurry to conventional (plow) tillage (CT) and no tillage (NT) soils. Long-term swine slurry application did not affect soil organic carbon. Some chemical properties, such as calcium, base saturation, and aluminum saturation were significantly different within and between tillages for various application rates. Available P and microbial parameters were significantly affected by slurry addition. Depending on tillage, soil microbial biomass and enzyme activity increased up to 120 m(3) ha(-1) year(-1) in all application rates. The NT system had higher microbial biomass and activity than CT at all application levels. There was an inverse relationship between the metabolic quotient (qCO2) and MBC, and the qCO2 was 53% lower in NT than CT. Swine slurry increased overall acid phosphatase activity, but the phosphatase produced per unit of microbial biomass decreased. A comparison of data obtained in the 3rd and 15th years of swine slurry application indicated that despite slurry application the CT system degraded with time while the NT system had improved values of soil quality indicators. For these Brazilian oxisols, swine slurry amendment was insufficient to maintain soil quality parameters in annual crop production without additional changes in tillage management. Copyright © 2014 Elsevier B.V. All rights reserved.

Vertical distribution of bacterial community is associated with the degree of soil organic matter decomposition in the active layer of moist acidic tundra.

PubMed

Kim, Hye Min; Lee, Min Jin; Jung, Ji Young; Hwang, Chung Yeon; Kim, Mincheol; Ro, Hee-Myong; Chun, Jongsik; Lee, Yoo Kyung

2016-11-01

The increasing temperature in Arctic tundra deepens the active layer, which is the upper layer of permafrost soil that experiences repeated thawing and freezing. The increasing of soil temperature and the deepening of active layer seem to affect soil microbial communities. Therefore, information on soil microbial communities at various soil depths is essential to understand their potential responses to climate change in the active layer soil. We investigated the community structure of soil bacteria in the active layer from moist acidic tundra in Council, Alaska. We also interpreted their relationship with some relevant soil physicochemical characteristics along soil depth with a fine scale (5 cm depth interval). The bacterial community structure was found to change along soil depth. The relative abundances of Acidobacteria, Gammaproteobacteria, Planctomycetes, and candidate phylum WPS-2 rapidly decreased with soil depth, while those of Bacteroidetes, Chloroflexi, Gemmatimonadetes, and candidate AD3 rapidly increased. A structural shift was also found in the soil bacterial communities around 20 cm depth, where two organic (upper Oi and lower Oa) horizons are subdivided. The quality and the decomposition degree of organic matter might have influenced the bacterial community structure. Besides the organic matter quality, the vertical distribution of bacterial communities was also found to be related to soil pH and total phosphorus content. This study showed the vertical change of bacterial community in the active layer with a fine scale resolution and the possible influence of the quality of soil organic matter on shaping bacterial community structure.

40 CFR 280.63 - Initial site characterization.

Code of Federal Regulations, 2011 CFR

2011-07-01

... site investigations concerning the following factors: surrounding populations, water quality, use and approximate locations of wells potentially affected by the release, subsurface soil conditions, locations of...

Experimental forest watershed studies contribution to the effect of disturbances on water quality

Treesearch

Daniel G. Neary

2012-01-01

The most sustainable and best quality fresh water sources in the world originate in forested watersheds (Dissmeyer 2000, Brooks et al. 2003, Barten and Ernst 2004). The biological, chemical, and physical characteristics of forest soils are particularly well suited to delivering high quality water to streams, and moderating the climatic extremes which affect stream...

Assessing the radar rainfall estimates in watershed-scale water quality model

USDA-ARS?s Scientific Manuscript database

Watershed-scale water quality models are effective science-based tools for interpreting change in complex environmental systems that affect hydrology cycle, soil erosion and nutrient fate and transport in watershed. Precipitation is one of the primary input data to achieve a precise rainfall-runoff ...

Chemical, physical and biological factors affecting wood decomposition in forest soils

Treesearch

Martin Jurgensen; Peter Laks; David Reed; Anne Collins; Deborah Page-Dumroese; Douglas Crawford

2004-01-01

Organic matter (OM) decomposition is an important variable in forest productivity and determining the potential of forest soils to sequester atmospheric CO2 (Grigal and Vance 2000; Kimble et al. 2003). Studies using OM from a particular location gives site-specific decomposition information, but differences in OM type and quality make it difficult to compare results...

Soil Disturbance Monitoring in the USDA Forest Service, Pacific Northwest Region

Treesearch

Steven W. Howes

2006-01-01

In order to make reasoned decisions, USDA Forest Service managers must understand how changes in specific indicators of soil quality resulting from project implementation affect long-term forest productivity and watershed health. They must also be able to efficiently and economically assess the degree and extent of such changes across specified areas and adjust...

Synchrony of net nitrogen mineralization and maize nitrogen uptake following applications of composted and fresh swine manure in the Midwest U.S.

USDA-ARS?s Scientific Manuscript database

Understanding how the quality of organic soil amendments affects the synchrony of nitrogen (N) mineralization and plant N uptake is critical for optimal agronomic N management and environmental protection. Composting solid livestock manures prior to soil application has been promoted to increase N s...

Effect of biosolid waste compost on soil respiration in salt-affected soils

NASA Astrophysics Data System (ADS)

Raya, Silvia; Gómez, Ignacio; García, Fuensanta; Navarro, José; Jordán, Manuel Miguel; Belén Almendro, María; Martín Soriano, José

2013-04-01

A great part of mediterranean soils are affected by salinization. This is an important problem in semiarid areas increased by the use of low quality waters, the induced salinization due to high phreatic levels and adverse climatology. Salinization affects 25% of irrigated agriculture, producing important losses on the crops. In this situation, the application of organic matter to the soil is one of the possible solutions to improve their quality. The main objective of this research was to asses the relation between the salinity level (electrical conductivity, EC) in the soil and the response of microbial activity (soil respiration rate) after compost addition. The study was conducted for a year. Soil samples were collected near to an agricultural area in Crevillente and Elche, "El Hondo" Natural Park (Comunidad de Regantes from San Felipe Neri). The experiment was developed to determine and quantify the soil respiration rate in 8 different soils differing in salinity. The assay was done in close pots -in greenhouse conditions- containing soil mixed with different doses of sewage sludge compost (2, 4 and 6%) besides the control. They were maintained at 60% of water holding capacity (WHC). Soil samples were analyzed every four months for a year. The equipment used to estimate the soil respiration was a Bac-Trac and CO2 emitted by the soil biota was measured and quantified by electrical impedance changes. It was observed that the respiration rate increases as the proportion of compost added to each sample increases as well. The EC was incremented in each sampling period from the beginning of the experiment, probably due to the fact that soils were in pots and lixiviation was prevented, so the salts couldńt be lost from soil. Over time the compost has been degraded and, it was more susceptible to be mineralized. Salts were accumulated in the soil. Also it was observed a decrease of microbial activity with the increase of salinity in the soil. Keywords: soil respiration, compost, electrical conductivity, salinization, Bac-Trac References: Abdelbasset Lakhdar, Mokded Rabhi, Tahar Ghnaya, Francesco Montemurro, Naceur Jedidi , Chedly Abdelly. Effectiveness of compost use in salt-affected soil. Journal of Hazardous Materials 171 (2009) pp 29-37. M. Tejada, C. Garcia, J.L. Gonzalez , M.T. Hernandez . Use of organic amendment as a strategy for saline soil remediation:Influence on the physical, chemical and biological properties of soil. Soil Biology & Biochemistry 38 (2006) pp 1413-1421. I. Gomez; J.M. Disla Soriano; J. Navarro-Pedreño; F. García-Orenes; M.B. Almendro-Candel; M.M. Jordan. Quantification of soil respiration in different saline soil of Alicante (Spain). EGU General Assembly (2012). Viena. Ed. Geophysycal Research Abstracts. Vol 14 EGU2012-2399,(2012). (Acknowledgements: This work was supported by the Spanish MICINN. Project Ref.: CGL2009-11194)

Assessment of groundwater and soil quality for agricultural purposes in Kopruoren basin, Kutahya, Turkey

NASA Astrophysics Data System (ADS)

Arslan, Sebnem

2017-07-01

This research evaluated the irrigation water and agricultural soil quality in the Kopruoren Basin by using hierarchical cluster analysis. Physico-chemical properties and major ion chemistry of 19 groundwater samples were used to determine the irrigation water quality indices. The results revealed out that the groundwaters are in general suitable for irrigation and have low sodium hazard, although they are very hard in nature due to the dominant presence of Ca+2, Mg+2 and HCO3- ions. Water samples contain arsenic in concentrations below the recommended guidelines for irrigation (59.7 ± 14.7 μg/l), however, arsenic concentrations in 89% of the 9 soil samples exceed the maximum allowable concentrations set for agricultural soils (81 ± 24.3 mg/kg). Nickel element, albeit not present in high concentrations in water samples, is enriched in all of the agricultural soil samples (390 ± 118.2 mg/kg). Hierarchical cluster analysis studies conducted to identify the sources of chemical constituents in water and soil samples elicited that the chemistry of the soils in the study area are highly impacted by the soil parent material and both geogenic and anthropogenic pollution sources are responsible for the metal contents of the soil samples. On the other hand, water chemistry in the area is affected by water-rock interactions, anthropogenic and agricultural pollution.

Urban cultivation in allotments maintains soil qualities adversely affected by conventional agriculture.

PubMed

Edmondson, Jill L; Davies, Zoe G; Gaston, Kevin J; Leake, Jonathan R

2014-08-01

Modern agriculture, in seeking to maximize yields to meet growing global food demand, has caused loss of soil organic carbon (SOC) and compaction, impairing critical regulating and supporting ecosystem services upon which humans also depend. Own-growing makes an important contribution to food security in urban areas globally, but its effects on soil qualities that underpin ecosystem service provision are currently unknown. We compared the main indicators of soil quality; SOC storage, total nitrogen (TN), C : N ratio and bulk density (BD) in urban allotments to soils from the surrounding agricultural region, and between the allotments and other urban greenspaces in a typical UK city. A questionnaire was used to investigate allotment management practices that influence soil properties. Allotment soils had 32% higher SOC concentrations and 36% higher C : N ratios than pastures and arable fields and 25% higher TN and 10% lower BD than arable soils. There was no significant difference between SOC concentration in allotments and urban non-domestic greenspaces, but it was higher in domestic gardens beneath woody vegetation. Allotment soil C : N ratio exceeded that in non-domestic greenspaces, but was lower than that in garden soil. Three-quarters of surveyed allotment plot holders added manure, 95% composted biomass on-site, and many added organic-based fertilizers and commercial composts. This may explain the maintenance of SOC, C : N ratios, TN and low BD, which are positively associated with soil functioning. Synthesis and applications . Maintenance and protection of the quality of our soil resource is essential for sustainable food production and for regulating and supporting ecosystem services upon which we depend. Our study establishes, for the first time, that small-scale urban food production can occur without the penalty of soil degradation seen in conventional agriculture, and maintains the high soil quality seen in urban greenspaces. Given the involvement of over 800 million people in urban agriculture globally, and its important contribution to food security, our findings suggest that to better protect soil functions, local, national and international urban planning and policy making should promote more urban own-growing in preference to further intensification of conventional agriculture to meet increasing food demand.

Urban cultivation in allotments maintains soil qualities adversely affected by conventional agriculture

PubMed Central

Edmondson, Jill L; Davies, Zoe G; Gaston, Kevin J; Leake, Jonathan R

2014-01-01

Modern agriculture, in seeking to maximize yields to meet growing global food demand, has caused loss of soil organic carbon (SOC) and compaction, impairing critical regulating and supporting ecosystem services upon which humans also depend. Own-growing makes an important contribution to food security in urban areas globally, but its effects on soil qualities that underpin ecosystem service provision are currently unknown. We compared the main indicators of soil quality; SOC storage, total nitrogen (TN), C : N ratio and bulk density (BD) in urban allotments to soils from the surrounding agricultural region, and between the allotments and other urban greenspaces in a typical UK city. A questionnaire was used to investigate allotment management practices that influence soil properties. Allotment soils had 32% higher SOC concentrations and 36% higher C : N ratios than pastures and arable fields and 25% higher TN and 10% lower BD than arable soils. There was no significant difference between SOC concentration in allotments and urban non-domestic greenspaces, but it was higher in domestic gardens beneath woody vegetation. Allotment soil C : N ratio exceeded that in non-domestic greenspaces, but was lower than that in garden soil. Three-quarters of surveyed allotment plot holders added manure, 95% composted biomass on-site, and many added organic-based fertilizers and commercial composts. This may explain the maintenance of SOC, C : N ratios, TN and low BD, which are positively associated with soil functioning. Synthesis and applications. Maintenance and protection of the quality of our soil resource is essential for sustainable food production and for regulating and supporting ecosystem services upon which we depend. Our study establishes, for the first time, that small-scale urban food production can occur without the penalty of soil degradation seen in conventional agriculture, and maintains the high soil quality seen in urban greenspaces. Given the involvement of over 800 million people in urban agriculture globally, and its important contribution to food security, our findings suggest that to better protect soil functions, local, national and international urban planning and policy making should promote more urban own-growing in preference to further intensification of conventional agriculture to meet increasing food demand. PMID:25641978

Soil, Food Security and Human Health

NASA Astrophysics Data System (ADS)

Oliver, Margaret

2017-04-01

"Upon this handful of soil our survival depends. Husband it and it will grow food, our fuel, and our shelter and surround us with beauty. Abuse it and the soil will collapse and die, taking humanity with it" Vedas Sanskrit Scripture, 1500 BC. As the world's population increases issues of food security become more pressing as does the need to sustain soil fertility and to minimize soil degradation. Soil and land are finite resources, and agricultural land is under severe competition from many other uses. Lack of adequate food and food of poor nutritional quality lead to under-nutrition of different degrees, all of which can cause ill- or suboptimal-health. The soil can affect human health directly and indirectly. Direct effects of soil or its constituents result from its ingestion, inhalation or absorption. For example, hook worms enter the body through the skin and cause anaemia, and fungi and dust can be inhaled resulting in respiratory problems. The soil is the source of actinomycetes on which our earliest antibiotics are based (actinomycin, neomycin and streptomycin). Furthermore, it is a potential reservoir of new antibiotics with methods such as functional metagenomics to identify antibiotic resistant genes. Indirect effects of soil arise from the quantity and quality of food that humans consume. Trace elements can have both beneficial and toxic effects on humans, especially where the range for optimal intake is narrow as for selenium. Deficiencies of four trace elements, iodine, iron, selenium and zinc, will be considered because of their substantial effects on human health. Relations between soil and human health are often difficult to extricate because of the many confounding factors present such as the source of food, social factors and so on. Nevertheless, recent scientific understanding of soil processes and factors that affect human health are enabling greater insight into the effects of soil on our health. Multidisciplinary research that includes soil science, agronomy, agricultural sustainability, toxicology, epidemiology and the medical sciences will promote greater understanding of the complex relationships between soil and human health.

Soil-transmitted Helminthiasis in the United States: a systematic review--1940-2010.

PubMed

Starr, Michelle C; Montgomery, Susan P

2011-10-01

The epidemiology of soil-transmitted helminth infections (hookworm, Trichuris trichiura, Ascaris lumbricoides, and Strongyloides stercoralis) in the United States is poorly understood. To gain understanding of the status of disease, a systematic review was performed to assess the prevalence of soil-transmitted helminth infections in the United States. Of all studies reviewed, 14 were designated as high-quality. High-quality studies were published from 1942 to 1982 and showed that infection was prevalent throughout the southern United States and Appalachia as recently as 1982, finding that hookworm (19.6%), T. trichiura (55.2%), A. lumbricoides (49.4%), and S. stercoralis (3.8%) affected significant percentages of the population. However, because the most recent high-quality studies were published over 25 years ago, the literature does not provide sufficient data to assess current endemic transmission. Because the status of disease remains unclear, there is a need for additional studies to determine if soil-transmitted helminths remain endemic in the United States.

Consequences of using different soil texture determination methodologies for soil physical quality and unsaturated zone time lag estimates.

PubMed

Fenton, O; Vero, S; Ibrahim, T G; Murphy, P N C; Sherriff, S C; Ó hUallacháin, D

2015-11-01

Elucidation of when the loss of pollutants, below the rooting zone in agricultural landscapes, affects water quality is important when assessing the efficacy of mitigation measures. Investigation of this inherent time lag (t(T)) is divided into unsaturated (t(u)) and saturated (t(s)) components. The duration of these components relative to each other differs depending on soil characteristics and the landscape position. The present field study focuses on tu estimation in a scenario where the saturated zone is likely to constitute a higher proportion of t(T). In such instances, or where only initial breakthrough (IBT) or centre of mass (COM) is of interest, utilisation of site and depth specific "simple" textural class or actual sand-silt-clay percentages to generate soil water characteristic curves with associated soil hydraulic parameters is acceptable. With the same data it is also possible to estimate a soil physical quality (S) parameter for each soil layer which can be used to infer many other physical, chemical and biological quality indicators. In this study, hand texturing in the field was used to determine textural classes of a soil profile. Laboratory methods, including hydrometer, pipette and laser diffraction methods were used to determine actual sand-silt-clay percentages of sections of the same soil profile. Results showed that in terms of S, hand texturing resulted in a lower index value (inferring a degraded soil) than that of pipette, hydrometer and laser equivalents. There was no difference between S index values determined using the pipette, hydrometer and laser diffraction methods. The difference between the three laboratory methods on both the IBT and COM stages of t(u) were negligible, and in this instance were unlikely to affect either groundwater monitoring decisions, or to be of consequence from a policy perspective. When t(u) estimates are made over the full depth of the vadose zone, which may extend to several metres, errors resulting from the use of hydraulic parameters generated from hand texture data will be resultantly greater, and may lead to flawed predictions regarding the achievability of water policy targets. For this reason laboratory analysis, regardless of method, should be preferred to simple field assessments. Copyright © 2015 Elsevier B.V. All rights reserved.

County-scale spatial distribution of soil enzyme activities and enzyme activity indices in agricultural land: implications for soil quality assessment.

PubMed

Tan, Xiangping; Xie, Baoni; Wang, Junxing; He, Wenxiang; Wang, Xudong; Wei, Gehong

2014-01-01

Here the spatial distribution of soil enzymatic properties in agricultural land was evaluated on a county-wide (567 km(2)) scale in Changwu, Shaanxi Province, China. The spatial variations in activities of five hydrolytic enzymes were examined using geostatistical methods. The relationships between soil enzyme activities and other soil properties were evaluated using both an integrated total enzyme activity index (TEI) and the geometric mean of enzyme activities (GME). At the county scale, soil invertase, phosphatase, and catalase activities were moderately spatially correlated, whereas urease and dehydrogenase activities were weakly spatially correlated. Correlation analysis showed that both TEI and GME were better correlated with selected soil physicochemical properties than single enzyme activities. Multivariate regression analysis showed that soil OM content had the strongest positive effect while soil pH had a negative effect on the two enzyme activity indices. In addition, total phosphorous content had a positive effect on TEI and GME in orchard soils, whereas alkali-hydrolyzable nitrogen and available potassium contents, respectively, had negative and positive effects on these two enzyme indices in cropland soils. The results indicate that land use changes strongly affect soil enzyme activities in agricultural land, where TEI provides a sensitive biological indicator for soil quality.

Soil physical conditions as livestock treading effect in tropical Agroecosystem of dryland and strategies to mitigate desertification risk

NASA Astrophysics Data System (ADS)

Florentino, A.; Torres, D.; Ospina, A.; Contreras, J.; Palma, Z.; Silvera, J.

2012-04-01

Soil degradation in natural ecosystem of arid and semi-arid zones of Venezuela due to livestock treading (goats) it is an important problem that affect their environment functions; increase soil erodibility, bulk density, water losses and reduce porosity, water infiltration rate and soil structural stability. The presence of biological crust (BSC) in this type of soil it is very common. The objective of this study was to evaluate the soil surface physical quality through the use of selected indicators, mainly some of that related to structural stability, infiltrability and the prediction of soil erosion risk in two zones of Lara state: 1) Quíbor (QUI) and 2) Humocaro Bajo (HB). The study was conducted on two selected plots (30 m x 20 m) in each zone, with natural vegetation and BSC cover, with areas affected by different degree of compaction due to treading in the paths where the goats are moving. Five sites per plot (50 cm x 50 cm) under vegetation cover and five sites over the path with bare soil were sampled (0-7,5 and 7,5-15 cm depth). The results showed that soil macroaggregate stability (equivalent diameter of aggregates >0,25 mm) was significantly higher (p<0,05 %) in soil with vegetation cover and BSC compared with bare soil. Sealing index, as a measure of aggregate stability, determined in laboratory under simulated rain and expressed as hydraulic conductivity of soil surface sealing (Kse), decreased with decreasing soil vegetation cover and the presence of BSC. However, Ksei (i: inicial) and Ksef (f: final) were significantly greater in soil with more than 75 % of BSC in comparison to bare soils. The sealing index it is used to for to estimate changes in soil water losses. As the sealing index increases, the susceptibility of the soil to undergo surface sealing or slaking decrease. These results suggested that soil physical properties are potential indicators of soil quality with regard to soil erodibility and showed that soils under vegetation cover had higher quality level than bare soils. Some predictive regression equation had a high R2 value and was a useful tool for to evaluate the risk of extreme climatic changes and to mitigate their detrimental effects. We conclude that the global climatic change (CCG) will have a negative effect on these agroecosystems functions, mainly in soil and water conservation, carbon sequestration, and productivity. Natural recovery of soil physical properties from treading damage of pastoral soils will be possible in the future with the implementation of soil management strategies, mainly through re-vegetation and recuperation of the BSC. Key word: Soil structure; aggregate stability; soil sealing index; hydraulic conductivity of surface sealing.

The potential of cover crops for improving soil function

NASA Astrophysics Data System (ADS)

Stoate, Chris; Crotty, Felicity

2017-04-01

Cover crops can be grown over the autumn and winter ensuring green cover throughout the year. They have been described as improving soil structure, reducing soil erosion and potentially even a form of grass weed control. These crops retain nutrients within the plant, potentially making them available for future crops, as well as increasing soil organic matter. Over the last three years, we have investigated how different cover crop regimes affect soil quality. Three separate experiments over each autumn/winter period have investigated how different cover crops affect soil biology, physics and chemistry, with each experiment building on the previous one. There have been significant effects of cover crops on soil structure, as well as significantly lower weed biomass and increased yields in the following crop - in comparison to bare stubble. For example, the effect of drilling the cover crops on soil structure in comparison to a bare stubble control that had not been driven on by machinery was quantified, and over the winter period the soil structure of the cover crop treatments changed, with compaction reduced in the cover crop treatments, whilst the bare stubble control remained unchanged. Weeds were found in significantly lower biomass in the cover crop mixes in comparison to the bare stubble control, and significantly lower weed biomass continued to be found in the following spring oat crop where the cover crops had been, indicating a weed suppressive effect that has a continued legacy in the following crop. The following spring oats have shown similar results in the last two years, with higher yields in the previous cover crop areas compared to the bare stubble controls. Overall, these results are indicating that cover crops have the potential to provide improvements to soil quality, reduce weeds and improve yields. We discuss the economic implications.

Sedimentation and Its Impacts/Effects on River System and Reservoir Water Quality: case Study of Mazowe Catchment, Zimbabwe

NASA Astrophysics Data System (ADS)

Tundu, Colleta; Tumbare, Michael James; Kileshye Onema, Jean-Marie

2018-04-01

Sediment delivery into water sources and bodies results in the reduction of water quantity and quality, increasing costs of water purification whilst reducing the available water for various other uses. The paper gives an analysis of sedimentation in one of Zimbabwe's seven rivers, the Mazowe Catchment, and its impact on water quality. The Revised Universal Soil Loss Equation (RUSLE) model was used to compute soil lost from the catchment as a result of soil erosion. The model was used in conjunction with GIS remotely sensed data and limited ground observations. The estimated annual soil loss in the catchment indicates soil loss ranging from 0 to 65 t ha yr-1. Bathymetric survey at Chimhanda Dam showed that the capacity of the dam had reduced by 39 % as a result of sedimentation and the annual sediment deposition into Chimhanda Dam was estimated to be 330 t with a specific yield of 226 t km-2 yr-1. Relationship between selected water quality parameters, TSS, DO, NO3, pH, TDS, turbidity and sediment yield for selected water sampling points and Chimhanda Dam was analyzed. It was established that there is a strong positive relationship between the sediment yield and the water quality parameters. Sediment yield showed high positive correlation with turbidity (0.63) and TDS (0.64). Water quality data from Chimhanda treatment plant water works revealed that the quality of water is deteriorating as a result of increase in sediment accumulation in the dam. The study concluded that sedimentation can affect the water quality of water sources.

Physiological and biochemical perspectives of non-salt tolerant plants during bacterial interaction against soil salinity.

PubMed

Radhakrishnan, Ramalingam; Baek, Kwang Hyun

2017-07-01

Climatic changes on earth affect the soil quality of agricultural lands, especially by increasing salt deposition in soil, which results in soil salinity. Soil salinity is a major challenge to growth and reproduction among glycophytes (including all crop plants). Soil bacteria present in the rhizosphere and/or roots naturally protect plants from the adverse effects of soil salinity by reprogramming the stress-induced physiological changes in plants. Bacteria can enrich the soil with major nutrients (nitrogen, phosphorus, and potassium) in a form easily available to plants and prevent the transport of excess sodium to roots (exopolysaccharides secreted by bacteria bind with sodium ions) for maintaining ionic balance and water potential in cells. Salinity also affects plant growth regulators and suppresses seed germination and root and shoot growth. Bacterial secretion of indole-3-acetic acid and gibberellins compensates for the salt-induced hormonal decrease in plants, and bacterial 1-aminocyclopropane-1-carboxylate (ACC) deaminase synthesis decreases ethylene production to stimulate plant growth. Furthermore, bacteria modulate the redox state of salinity-affected plants by enhancing antioxidants and polyamines, which leads to increased photosynthetic efficiency. Bacteria-induced accumulation of compatible solutes in stressed plants regulates plant cellular activities and prevents salt stress damage. Plant-bacterial interaction reprograms the expression of salt stress-responsive genes and proteins in salinity-affected plants, resulting in a precise stress mitigation metabolism as a defense mechanism. Soil bacteria increase the fertility of soil and regulate the plant functions to prevent the salinity effects in glycophytes. This review explains the current understanding about the physiological changes induced in glycophytes during bacterial interaction to alleviate the adverse effects of soil salinity stress. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Soil physical properties changed induced by dry-wet cycles in the water-level fluctuation zone of Three Gorges Reservoir region, China

NASA Astrophysics Data System (ADS)

Cui, Junfang; Tang, Xiangyu; Zhang, Wei

2017-04-01

In southwest China, a grand hydraulic engineering called Three Gorges Dam (TGD) was completed and under full power run since 2009, making a total area of 349 km2 along Yangtze River exposing the dry-wet cycles by its impounding of water step by step from the elevations of 135 m in summer season to 175 m in winter season at each year. As populated area, the environmental issues aroused by the TGR have centered on water quality, biodiversity, sedimentation, downstream riverbed erosion and pollutants (both heavy metals and organic pollutants) transportation. All these are regulated or affected by soil structure and pore network, directly or indirectly. Thus, the study of soil physical quality changed induced by these seasonal dry-wet cycles is crucial. The objective of this study is: (1) to describe soil structural status in WLF zone of TGR by combination of laboratory measures and visual evaluation method; (2) to describe the pore system in this zone by both SWRC and CT images; and (3) to address the changes of soil physical quality changed by seasonal dry-wet cycles. Our results showed a deterioration of soil structure (indicated by a high Sq score in VESS) and soil aggregate stability (indicated by low MWD and the mass fractal dimension Dm) in lower land of TGR. The data from both soil water retention curve and micro-CT image demonstrates a going -worse of soil physical quality by decreasing of soil pore number and porosity as well as a shift of drainable micro-pores (0.1 < r < 125 µm) to non-drainable micro-pores (r < 0.1 µm) in the lower land of TGR.

Impacts of soil conditioners and water table management on phosphorus loss in tile drainage from a clay loam soil.

PubMed

Zhang, T Q; Tan, C S; Zheng, Z M; Welacky, T W; Reynolds, W D

2015-03-01

Adoption of waste-derived soil conditioners and refined water management can improve soil physical quality and crop productivity of fine-textured soils. However, the impacts of these practices on water quality must be assessed to ensure environmental sustainability. We conducted a study to determine phosphorus (P) loss in tile drainage as affected by two types of soil conditioners (yard waste compost and swine manure compost) and water table management (free drainage and controlled drainage with subirrigation) in a clay loam soil under corn-soybean rotation in a 4-yr period from 1999 to 2003. Tile drainage flows were monitored and sampled on a year-round continuous basis using on-site auto-sampling systems. Water samples were analyzed for dissolved reactive P (DRP), particulate P (PP), and total P (TP). Substantially greater concentrations and losses of DRP, PP, and TP occurred with swine manure compost than with control and yard waste compost regardless of water table management. Compared with free drainage, controlled drainage with subirrigation was an effective way to reduce annual and cumulative losses of DRP, PP, and TP in tile drainage through reductions in flow volume and P concentration with control and yard waste compost but not with swine manure compost. Both DRP and TP concentrations in tile drainage were well above the water quality guideline for P, affirming that subsurface loss of P from fine-textured soils can be one critical source for freshwater eutrophication. Swine manure compost applied as a soil conditioner must be optimized by taking water quality impacts into consideration. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Does Short-term Litter Input Manipulation Affect Soil Respiration and the Carbon-isotopic Signature of Soil Respired CO2

NASA Astrophysics Data System (ADS)

Cheng, X.; Wu, J.

2016-12-01

Global change greatly alters the quality and quantity of plant litter inputs to soils, and further impacts soil organic matter (SOM) dynamics and soil respiration. However, the process-based understanding of how soil respiration may change with future shift in litter input is not fully understood. The Detritus Input and Removal Treatment (DIRT) experiment was conducted in coniferous forest (Platycladus orientalis (Linn.) Franco) ecosystem of central China to investigate the impact of above- and belowground litter input on soil respiration and the carbon-isotopic signature of soil respired CO2. Short-term (1-2 years) litter input manipulation significantly affected soil respiration, based on annual flux values, soil respiration was 31.9%, 20.5% and 37.2% lower in no litter (NL), no root (NR) and no input (NRNL), respectively, compared to control (CK). Whereas double litter (DL) treatment increased soil respiration by 9.1% compared to CK. The recalcitrance index of carbon (RIC) and the relative abundance of fungi increased under litter removal or root exclusion treatment (NL, NR and NRNL) compared to CK. Basal soil respiration was positively related to liable C and microbial biomass and negatively related to RIC and fungi to bacteria (F: B) ratio. The carbon-isotopic signature of soil respired CO2 enriched under litter removal and no input treatment, and slightly depleted under litter addition treatment compared to CK. Our results suggest that short-term litter input manipulation can affect the soil respiration by altering substrate availability and microbial community structure, and also impact the carbon-isotopic signature of soil respired CO2 possibly duo to change in the component of soil respiration and soil microclimate.

Production of biochar out of organic urban waste to amend salt affected soils in the basin of Mexico

NASA Astrophysics Data System (ADS)

Chavez Garcia, Elizabeth; Siebe, Christina

2016-04-01

Biochar is widely recognized as an efficient tool for carbon sequestration and soil fertility. The understanding of its chemical and physical properties, strongly related to the biomass and production conditions, is central to identify the most suitable application of biochar. On the other hand, salt affected soils reduce the value and productivity of extensive areas worldwide. One feasible option to recover them is to add organic amendments, which improve water holding capacity and increase sorption sites for cations as sodium. The former lake Texcoco in the basin of Mexico has been a key area for the control of surface run-off and air quality of Mexico City. However, the high concentrations of soluble salts in their soils do not allow the development of a vegetation cover that protects the soil from wind erosion, being the latter the main cause of poor air quality in the metropolitan area during the dry season. On the other hand, the population of the city produces daily 2000 t of organic urban wastes, which are currently composted. Thus, we tested if either compost or biochar made out of urban organic waste can improve the salt affected soils of former lake Texcoco to grow grass and avoid wind erosion. We examined the physico-chemical properties of biochar produced from urban organic waste under pyrolysis conditions. We also set up a field experiment to evaluate the addition of these amendments into the saline soils of Texcoco. Our preliminary analyses show biochar yield was ca. 40%, it was mainly alkaline (pH: 8-10), with a moderate salt content (electrical conductivity: 0.5-3 mS/cm). We show also results of the initial phase of the field experiment in which we monitor the electrical conductivity, pH, water content, water tension and soil GHG fluxes on small plots amended with either biochar or compost in three different doses.

Changes in microbial community characteristics and soil organic matter with nitrogen additions in two tropical forests

Treesearch

Daniela F. Cusack; Whendee L. Silver; Margaret S. Torn; Sarah D. Burton; Mary K. Firestone

2011-01-01

Microbial communities and their associated enzyme activities affect the amount and chemical quality of carbon (C) in soils. Increasing nitrogen (N) deposition, particularly in N-rich tropical forests, is likely to change the composition and behavior of microbial communities and feed back on ecosystem structure and function. This study presents a novel assessment of...

Biogeochemical cycling and chemical fluxes in a managed northern forested wetland, Michigan, USA

Treesearch

James McLaughlin; Emily Calhoon; Margaret Gale; Martin Jurgensen; Carl Trettin

2011-01-01

Forest harvesting and subsequent regeneration treatments may cause changes in soil and solution chemistry that adversely affect forest productivity and environmental quality. The objective of this study was to assess soil carbon (C), nitrogen (N), and base cation pools and fluxes, and to construct a hydrogen ion (H+) mass balance to identify major processes controlling...

Water quality, sediment, and soil characteristics near Fargo-Moorhead urban areas as affected by major flooding of the Red River of the north

Treesearch

A.C. Guy; T.M. DeSutter; F.X.M. Casey; R. Kolka; H. Hakk

2012-01-01

Spring flooding of the Red River of the North (RR) is common, but little information exits on how these flood events affect water and overbank sediment quality within an urban area. With the threat of the spring 2009 flood in the RR predicted to be the largest in recorded history and the concerns about the flooding of farmsteads, outbuildings, garages, and basements,...

Improving quality of textile wastewater with organic materials as multi soil layering

NASA Astrophysics Data System (ADS)

Supriyadi; Widijanto, H.; Pranoto; Dewi, AK

2016-02-01

On agricultural land, fresh water is needed especially for irrigation. Alternative ways to fulfill needs of fresh water is by utilizing wastewater from industry. Wastewater that produced in the industry in Surakarta is over flowing especially textile wastewater. Wastewater that produced from industry has many pollutants that affected decreasing fresh water quality for irrigation. Multi Soil Layering (MSL) is one of method that utilize the soil ability as main media by increasing its function of soil structure to purify wastewater, so it does not contaminate the environment and reusable. This research was purposed to know affectivity of organic materials (such as rice straw, baggase, sawdust, coconut fibre, and corncob) and dosage (5%, 10% and 25%) in MSL, also get alternative purification ways with easy and cheaper price as natural adsorbent. This study using field and laboratory experiment. The result shows that MSL can be an alternative method of purification of wastewater. The appropriate composition of organic materials that can be used as adsorbent is MSL with wood sawdust 10% dosage because it can increase pH, decrease the number of Cr, ammonia, and phosphate but less effective to decrease BOD and COD.

High heterogeneity in soil composition and quality in different mangrove forests of Venezuela.

PubMed

Otero, X L; Méndez, A; Nóbrega, G N; Ferreira, T O; Meléndez, W; Macías, F

2017-09-18

Mangrove forests play an important role in biogeochemical cycles of metals, nutrients, and C in coastal ecosystems. However, these functions could be strongly affected by the mangrove soil degradation. In this study, we performed an intensive sampling characterizing mangrove soils under different types of environment (lagoon/gulf) and vegetation (Rhizophora/Avicennia/dead mangrove) in the Venezuelan coast. To better understand the spatial heterogeneity of the composition and characteristics of the soils, a wide range of the soil attributes were analyzed. In general, the soils were anoxic (Eh < 200 mV), with a neutral pH and low concentration in toxic metals; nevertheless, they varied widely in the soil and its quality-defining parameters (e.g., clay contents, total organic carbon, Fe, Al, toxic trace metals). It is noteworthy that the mangroves presented a low Fe Pyrite content due to a limitation in the Fe oxyhydroxide contents, especially in soils with higher organic C content (TOC > 15%). Finally, the dead mangrove showed significantly lower amounts of TOC and fibers (in comparison to the well-preserved mangrove forest), which indicates that the C pools in mangrove soils are highly sensitive also to natural impact, such as ENSO.

Soil Quality in Mining Areas Undergoing Ecological Restoration

NASA Astrophysics Data System (ADS)

Dinarowski, Marcela; Casagrande, José Carlos; Bizuti, Denise T. G.; Silva, Luiz Gabriel; Soares, Marcio Roberto; Brancalion, Pedro H. S.

2014-05-01

Mining is one of the anthropogenic activities most impactful to natural resources, and can profoundly affect the resilience of ecosystems depending on the level of soil degradation. Ecological restoration has generated promising results even in situations of degradation as intense as those of mining. The aim of this study was to evaluate the quality of the soil in areas explored by the bauxite extraction undergoing restoration: recently mined, seven years, 20 years and native forest. The studied areas are located in the municipality of Poços de Caldas-MG, belonging to ALCOA Alumínio. The mined-out areas for seven and twenty years were uncompressed and received topsoil, liming and fertilization with nitrogen, phosphorus and potassium. Samples for chemical analyses of soil fertility were carried out at depths of 0-5, 5-10, 10-20, 20-40 and 40-60 cm. Soil quality was evaluated by pondered additive model. The parameters were considered organic matter (0.6) and bases saturation (0.4) for soil fertility function (0.6) and calcium (0.5) and aluminum saturation (0.5) for the function root development (0.4) - (the numbers in parentheses represent the weights attributed). Despite the high content, only the organic matter was not a parameter enough to classify the soil quality, once the native forest has very low base saturation (7%). The soil quality index(SQI) obtained allowed to classify the areas, being the first restored 20 years ago with SQI equal to 0.7 followed of the restored 7 years ago, native forest and newly mined with SQIs equal to 0.6, 04 and 0.3, respectively. The native tropical forests have low soil fertility, keeping by the cycling of nutrients. This demonstrates the need for the degraded areas, especially the mined, are uncompressed to allow storage of water and root development, in addition to the replacement of nutrients and soil acidity correction, especially high levels of aluminum saturation (66%) and low calcium (3 mmolcdm-3).

Sugarcane trash levels in soil affects the fungi but not bacteria in a short-term field experiment.

PubMed

Rachid, C T C C; Pires, C A; Leite, D C A; Coutinho, H L C; Peixoto, R S; Rosado, A S; Salton, J; Zanatta, J A; Mercante, F M; Angelini, G A R; Balieiro, Fabiano de Carvalho

2016-01-01

The sugarcane in Brazil is passing through a management transition that is leading to the abolition of pre-harvest burning. Without burning, large amounts of sugarcane trash is generated, and there is a discussion regarding the utilization of this biomass in the industry versus keeping it in the field to improve soil quality. To study the effects of the trash removal on soil quality, we established an experimental sugarcane plantation with different levels of trash over the soil (0%, 50% and 100% of the original trash deposition) and analyzed the structure of the bacterial and fungal community as the bioindicators of impacts. The soil DNA was extracted, and the microbial community was screened by denaturing gradient gel electrophoresis in two different seasons. Our results suggest that there are no effects from the different levels of trash on the soil chemistry and soil bacterial community. However, the fungal community was significantly impacted, and after twelve months, the community presented different structures among the treatments. Copyright © 2016. Published by Elsevier Editora Ltda.

Short-term effect of nutrient availability and rainfall distribution on biomass production and leaf nutrient content of savanna tree species.

PubMed

Barbosa, Eduardo R M; Tomlinson, Kyle W; Carvalheiro, Luísa G; Kirkman, Kevin; de Bie, Steven; Prins, Herbert H T; van Langevelde, Frank

2014-01-01

Changes in land use may lead to increased soil nutrient levels in many ecosystems (e.g. due to intensification of agricultural fertilizer use). Plant species differ widely in their response to differences in soil nutrients, and for savannas it is uncertain how this nutrient enrichment will affect plant community dynamics. We set up a large controlled short-term experiment in a semi-arid savanna to test how water supply (even water supply vs. natural rainfall) and nutrient availability (no fertilisation vs. fertilisation) affects seedlings' above-ground biomass production and leaf-nutrient concentrations (N, P and K) of broad-leafed and fine-leafed tree species. Contrary to expectations, neither changes in water supply nor changes in soil nutrient level affected biomass production of the studied species. By contrast, leaf-nutrient concentration did change significantly. Under regular water supply, soil nutrient addition increased the leaf phosphorus concentration of both fine-leafed and broad-leafed species. However, under uneven water supply, leaf nitrogen and phosphorus concentration declined with soil nutrient supply, this effect being more accentuated in broad-leafed species. Leaf potassium concentration of broad-leafed species was lower when growing under constant water supply, especially when no NPK fertilizer was applied. We found that changes in environmental factors can affect leaf quality, indicating a potential interactive effect between land-use changes and environmental changes on savanna vegetation: under more uneven rainfall patterns within the growing season, leaf quality of tree seedlings for a number of species can change as a response to changes in nutrient levels, even if overall plant biomass does not change. Such changes might affect herbivore pressure on trees and thus savanna plant community dynamics. Although longer term experiments would be essential to test such potential effects of eutrophication via changes in leaf nutrient concentration, our findings provide important insights that can help guide management plans that aim to preserve savanna biodiversity.

Predicted Infiltration for Sodic/Saline Soils from Reclaimed Coastal Areas: Sensitivity to Model Parameters

PubMed Central

She, Dongli; Yu, Shuang'en; Shao, Guangcheng

2014-01-01

This study was conducted to assess the influences of soil surface conditions and initial soil water content on water movement in unsaturated sodic soils of reclaimed coastal areas. Data was collected from column experiments in which two soils from a Chinese coastal area reclaimed in 2007 (Soil A, saline) and 1960 (Soil B, nonsaline) were used, with bulk densities of 1.4 or 1.5 g/cm3. A 1D-infiltration model was created using a finite difference method and its sensitivity to hydraulic related parameters was tested. The model well simulated the measured data. The results revealed that soil compaction notably affected the water retention of both soils. Model simulations showed that increasing the ponded water depth had little effect on the infiltration process, since the increases in cumulative infiltration and wetting front advancement rate were small. However, the wetting front advancement rate increased and the cumulative infiltration decreased to a greater extent when θ 0 was increased. Soil physical quality was described better by the S parameter than by the saturated hydraulic conductivity since the latter was also affected by the physical chemical effects on clay swelling occurring in the presence of different levels of electrolytes in the soil solutions of the two soils. PMID:25197699

Predicted infiltration for sodic/saline soils from reclaimed coastal areas: sensitivity to model parameters.

PubMed

Liu, Dongdong; She, Dongli; Yu, Shuang'en; Shao, Guangcheng; Chen, Dan

2014-01-01

This study was conducted to assess the influences of soil surface conditions and initial soil water content on water movement in unsaturated sodic soils of reclaimed coastal areas. Data was collected from column experiments in which two soils from a Chinese coastal area reclaimed in 2007 (Soil A, saline) and 1960 (Soil B, nonsaline) were used, with bulk densities of 1.4 or 1.5 g/cm(3). A 1D-infiltration model was created using a finite difference method and its sensitivity to hydraulic related parameters was tested. The model well simulated the measured data. The results revealed that soil compaction notably affected the water retention of both soils. Model simulations showed that increasing the ponded water depth had little effect on the infiltration process, since the increases in cumulative infiltration and wetting front advancement rate were small. However, the wetting front advancement rate increased and the cumulative infiltration decreased to a greater extent when θ₀ was increased. Soil physical quality was described better by the S parameter than by the saturated hydraulic conductivity since the latter was also affected by the physical chemical effects on clay swelling occurring in the presence of different levels of electrolytes in the soil solutions of the two soils.

Do agricultural terraces and forest fires recurrence in Mediterranean afforested micro-catchments alter soil quality and soil nutrient content?

NASA Astrophysics Data System (ADS)

E Lucas-Borja, Manuel; Calsamiglia, Aleix; Fortesa, Josep; García-Comendador, Julián; Gago, Jorge; Estrany, Joan

2017-04-01

Bioclimatic characteristics and intense human pressure promote Mediterranean ecosystems to be fire-prone. Afforestation processes resulting from the progressive land abandonment during the last decades led to greater biomass availability increasing the risk of large forest fires. Likewise, the abandonment and lack of maintenance in the terraced lands constitute a risk of land degradation in terms of soil quantity and quality. Despite the effects of fire and the abandonment of terraced lands on soil loss and physico-chemical properties are identified, it is not clearly understood how wildfires and abandonment of terraces affect soil quality and nutrients content. Microbiological soil parameters and soil enzymes activities are biomarkers of the soil microbial communitýs functional ability, which potentially enables them as indicators of change, disturbance or stress within the soil community. The objective of this study was to investigate the effects of terracing (abandoned and non-abandoned) on the soil enzyme activities, microbiological soil parameters and soil nutrients dynamics in three Mediterranean afforested micro-catchments (i.e., < 2 ha) under different forest fire recurrence in the last 20 years; i.e., unburned areas, burned once and burned twice. The combination of the presence of terraces and the recurrence of forest fire, thirty-six plots of 25 m2 were sampled along the these three micro-catchments collecting four replicas at the corners of each plot. The results elucidated how non-terraced and unburned plots presented the highest values of soil respiration rate and extracellular soil enzymes. Differences between experimental plots with different forest fire recurrence or comparing terraced and unburned plots with burned plots were weaker in relation to biochemical and microbiological parameters. Soil nutrient content showed an opposite trend with higher values in terraced plots, although differences were weaker. We conclude that terraced landscapes present poorer soil quality parameters due to land abandonment and the lack of terraced management. In addition, forest fire recurrence exacerbates soil degradation processes due to the direct effects on vegetation and soil properties.

Microbial response to salinity stress in a tropical sandy soil amended with native shrub residues or inorganic fertilizer.

PubMed

Sall, Saïdou Nourou; Ndour, Ndèye Yacine Badiane; Diédhiou-Sall, Siré; Dick, Richard; Chotte, Jean-Luc

2015-09-15

Soil degradation and salinization caused by inappropriate cultivation practices and high levels of saltwater intrusion are having an adverse effect on agriculture in Central Senegal. The residues of Piliostigma reticulatum, a local shrub that coexists with crops, were recently shown to increase particulate organic matter and improve soil quality and may be a promising means of alleviating the effects of salinization. This study compared the effects of inorganic fertilizer and P. reticulatum residues on microbial properties and the ability of soil to withstand salinity stress. We hypothesized that soils amended with P. reticulatum would be less affected by salinity stress than soils amended with inorganic fertilizer and control soil. Salinity stress was applied to soil from a field site that had been cultivated for 5 years under a millet/peanut crop rotation when microbial biomass, phospholipid fatty acid (PLFA) community profile, catabolic diversity, microbial activities were determined. Microbial biomass, nitrification potential and dehydrogenase activity were higher by 20%, 56% and 69% respectively in soil with the organic amendment. With salinity stress, the structure and activities of the microbial community were significantly affected. Although the biomass of actinobacteria community increased with salinity stress, there was a substantial reduction in microbial activity in all soils. The soil organically amended was, however, less affected by salinity stress than the control or inorganic fertilizer treatment. This suggests that amendment using P. reticulatum residues may improve the ability of soils to respond to saline conditions. Copyright © 2015 Elsevier Ltd. All rights reserved.

Interrill Erodibility of P and C on conventially and organically farmed Devon soils

NASA Astrophysics Data System (ADS)

Kuhn, N. J.

2012-04-01

Soil erosion can have significant off-site effects on water quality and thus human and habitat health. Apart from sedimentation, the transfer of nutrients, both dissolved and particulate, is a major concern. The particulate transfer of nutrients from agricultural land can occur either by rill or interrill erosion. Rill erosion is non-selective and affects only a limited extent of agricultural land. Interrill processes such as crusting, splash and raindrop-impacted wash, on the other hand, act on all cropland and affect the quality of the water from all areas generating runoff. A significant amount of phosphorus (P) is contained in the surface soil layer transformed by interrill processes annually. In the EU, the P content of a crusted (2 mm) surface layer corresponds to 4 to 40 kg ha-1 of P on arable land (1.094 mil km2). Therefore, the role of interrill processes and erosion for regional nutrient cycling requires close attention. Interrill erosion is a complex phenomenon, involving the detachment, transport and deposition of soil particles by raindrop impacted flow. Resistance to interrill erosion varies between soils depending on their physical, chemical and mineralogical properties. In addition, significant changes in soil resistance to interrill erosion occur during storms as a result of changes in surface roughness, cohesion and particle size. As a consequence, erosion on interrill areas is selective, moving the most easily detached small and/or light soil particles which are often enriched in clay, P and organic C. Commonly, the risk of erosion associated with organically farmed soils is lower than those farmed in a conventional way. This is attributed to greater aggregate stability and thus greater infiltration and lower erodibility. Erosion of nutrients on organically farmed soils is therefore considered to be reduced by the same order of magnitude than the amount of eroded soil compared to conventionally farmed soils. However, the selective nature of interrill erosion potentially counteracts this effect by the preferential removal of fine particles enriched in nutrients and soil organic matter. In this study, an experiment comparing the erodibility of P and C on organically and conventially farmed soils from Devon is presented. The results show a disproportional increase of P in sediment from the organically farmed soil, reducing the perceived benefit of organic farming on nutrient erosion by 80%. The pronounced P enrichment in the organically farmed soil is attributed to the higher concentrations of C and P as well as lower densities of the small particle fraction. The results, while very preliminary, indicate that the impact of soil management on off-site effects of erosion such as water quality can only be fully assessed when we understand the relevant erosion processes. They also indicate that some less than expected positive effects of changing soil management to improve water quality might be caused by the preferential erosion of P-bearing soil particles.

Mining-Related Sediment and Soil Contamination in a Large Superfund Site: Characterization, Habitat Implications, and Remediation.

PubMed

Juracek, K E; Drake, K D

2016-10-01

Historical mining activity (1850-1970) in the now inactive Tri-State Mining District provided an ongoing source of lead and zinc to the environment including the US Environmental Protection Agency Superfund site located in Cherokee County, southeast Kansas, USA. The resultant contamination adversely affected biota and caused human health problems and risks. Remediation in the Superfund site requires an understanding of the magnitude and extent of contamination. To provide some of the required information, a series of sediment and soil investigations were conducted in and near the Superfund site to characterize lead and zinc contamination in the aquatic and floodplain environments along the main-stem Spring River and its major tributaries. In the Superfund site, the most pronounced lead and zinc contamination, with concentrations that far exceed sediment quality guidelines associated with potential adverse biological effects, was measured for streambed sediments and floodplain soils located within or downstream from the most intensive mining-affected areas. Tributary streambeds and floodplains in affected areas are heavily contaminated with some sites having lead and zinc concentrations that are an order of magnitude (or more) greater than the sediment quality guidelines. For the main-stem Spring River, the streambed is contaminated but the floodplain is mostly uncontaminated. Measured lead and zinc concentrations in streambed sediments, lakebed sediments, and floodplain soils documented a persistence of the post-mining contamination on a decadal timescale. These results provide a basis for the prioritization, development, and implementation of plans to remediate contamination in the affected aquatic and floodplain environments within the Superfund site.

Mining-Related Sediment and Soil Contamination in a Large Superfund Site: Characterization, Habitat Implications, and Remediation

NASA Astrophysics Data System (ADS)

Juracek, K. E.; Drake, K. D.

2016-10-01

Historical mining activity (1850-1970) in the now inactive Tri-State Mining District provided an ongoing source of lead and zinc to the environment including the US Environmental Protection Agency Superfund site located in Cherokee County, southeast Kansas, USA. The resultant contamination adversely affected biota and caused human health problems and risks. Remediation in the Superfund site requires an understanding of the magnitude and extent of contamination. To provide some of the required information, a series of sediment and soil investigations were conducted in and near the Superfund site to characterize lead and zinc contamination in the aquatic and floodplain environments along the main-stem Spring River and its major tributaries. In the Superfund site, the most pronounced lead and zinc contamination, with concentrations that far exceed sediment quality guidelines associated with potential adverse biological effects, was measured for streambed sediments and floodplain soils located within or downstream from the most intensive mining-affected areas. Tributary streambeds and floodplains in affected areas are heavily contaminated with some sites having lead and zinc concentrations that are an order of magnitude (or more) greater than the sediment quality guidelines. For the main-stem Spring River, the streambed is contaminated but the floodplain is mostly uncontaminated. Measured lead and zinc concentrations in streambed sediments, lakebed sediments, and floodplain soils documented a persistence of the post-mining contamination on a decadal timescale. These results provide a basis for the prioritization, development, and implementation of plans to remediate contamination in the affected aquatic and floodplain environments within the Superfund site.

Mining-related sediment and soil contamination in a large Superfund site: Characterization, habitat implications, and remediation

USGS Publications Warehouse

Juracek, Kyle E.; Drake, K. D.

2016-01-01

Historical mining activity (1850–1970) in the now inactive Tri-State Mining District provided an ongoing source of lead and zinc to the environment including the US Environmental Protection Agency Superfund site located in Cherokee County, southeast Kansas, USA. The resultant contamination adversely affected biota and caused human health problems and risks. Remediation in the Superfund site requires an understanding of the magnitude and extent of contamination. To provide some of the required information, a series of sediment and soil investigations were conducted in and near the Superfund site to characterize lead and zinc contamination in the aquatic and floodplain environments along the main-stem Spring River and its major tributaries. In the Superfund site, the most pronounced lead and zinc contamination, with concentrations that far exceed sediment quality guidelines associated with potential adverse biological effects, was measured for streambed sediments and floodplain soils located within or downstream from the most intensive mining-affected areas. Tributary streambeds and floodplains in affected areas are heavily contaminated with some sites having lead and zinc concentrations that are an order of magnitude (or more) greater than the sediment quality guidelines. For the main-stem Spring River, the streambed is contaminated but the floodplain is mostly uncontaminated. Measured lead and zinc concentrations in streambed sediments, lakebed sediments, and floodplain soils documented a persistence of the post-mining contamination on a decadal timescale. These results provide a basis for the prioritization, development, and implementation of plans to remediate contamination in the affected aquatic and floodplain environments within the Superfund site.

Stratification and Storage of Soil Organic Carbon and Nitrogen as Affected by Tillage Practices in the North China Plain

PubMed Central

Zhang, Xiang-Qian; Kong, Fan-Lei; Chen, Fu; Lal, Rattan; Zhang, Hai-Lin

2015-01-01

Tillage practices can redistribute the soil profiles, and thus affects soil organic carbon (SOC), and its storage. The stratification ratio (SR) can be an indicator of soil quality. This study was conducted to determine tillage effects on the profile distribution of certain soil properties in winter wheat (Triticum aestivum L.) and summer maize (Zea mays L.) systems in the North China Plain (NCP). Three tillage treatments, including no till (NT), rotary tillage (RT), and plow tillage (PT), were established in 2001 in Luancheng County, Hebei Province. The concentration, storage, and SR of SOC and soil total nitrogen (TN) were assessed in both the wheat and maize seasons. Compared with RT and PT, the mean SRs for all depth ratios of SOC under NT increased by 7.85% and 30.61% during the maize season, and by 14.67% and 30.91% during the wheat season, respectively. The SR of TN for 0–5:30–50 cm increased by 140%, 161%, and 161% in the maize season, and 266%, 154%, and 122% in the wheat season compared to the SR for 0–5:5–10 cm under NT, RT and PT, respectively. The data indicated that SOC and TN were both concentrated in the surface-soil layers (0–10 cm) under NT but were distributed relatively evenly through the soil profile under PT. Meanwhile, the storage of SOC and TN was higher under NT for the surface soil (0–10 cm) but was higher under PT for the deeper soil (30–50 cm). Furthermore, the storage of SOC and TN was significantly related to SR of SOC and TN along the whole soil profile (P<0.0001). Therefore, SR could be used to explain and indicate the changes in the storage of SOC and TN. Further, NT stratifies SOC and TN, enhances the topsoil SOC storage, and helps to improve SOC sequestration and soil quality. PMID:26075391

Compositon of sediments transported by the wind at different heights

NASA Astrophysics Data System (ADS)

Iturri, Antonela; Funk, Roger; Leue, Martin; Sommer, Michael; Buschiazzo, Daniel

2017-04-01

Wind erosion (WE) is one of the most important degradation process of soils in arid- and semiarid environments in the world, affecting soil properties and adjacent ecosystems, including human health. Estimations about the amount of eroded soil are available in Argentina and in the world, but the quality of the eroded sediments, particularly the sorting effects in agricultural soils, has been scarcely studied. The trend of the different mineral and organic soil compounds, which enrich in different size classes, can define height distribution profiles. Therefore, the uppermost 2.5 cm of four agricultural loess soils that differ in granulometric composition were used for WE simulations in a wind tunnel. Particles with a diameter smaller than 10 µm (PM10) were collected with a laboratory dust generator. The bulk soil and all the sediment samples were characterized by the granulometric composition, the soil organic carbon (SOC) content and the mineral and organic functional groups. Despite different texture, the soils were subjected to similar sorting processes in height, but differed depending on their granulometry. There was a separation between coarser and finer soil particles in coarser textured soils, while finer textured soils were more homogeneous in all heights. This correlated with the preferential transport of Si-O from quartz and C-H, C=O and C-C from soil organic matter (SOM), which were transported in larger and/or denser particles at lower heights. O-H from clay minerals and C-O-C and C-O from polysaccharides, carbohydrates and derivatives from SOM were transported in higher heights. Despite similar SOC content in the bulk soils, both the amount and composition in the PM10 fractions was different. The SOC transported at higher heights was mostly composed of polysaccharides, carbohydrates and derivatives associated with clay minerals. The SOC in PM10 fractions of coarser-textured soils was dominated by labile C-H groups. According to the determined height distribution profiles, it can be deduced that WE may affect both soil quality and the soil C balance due to the sorting effects during transport.

SF Box--a tool for evaluating the effects on soil functions in remediation projects.

PubMed

Volchko, Yevheniya; Norrman, Jenny; Rosén, Lars; Norberg, Tommy

2014-10-01

Although remediation is usually aimed at reducing the risks posed by contaminants to human health and the environment, it is also desirable that the remediated soil within future green spaces is capable of providing relevant ecological functions, e.g., basis for primary production. Yet while addressing a contamination problem by reducing contaminant concentration and/or amounts in the soil, the remedial action itself can lead to soil structure disturbances, decline in organic matter and nutrient deficiencies, and in turn affect a soil's capacity to carry out its ecological soil functions. This article presents the Soil Function Box (SF Box) tool that is aimed to facilitate integration of information from suggested soil quality indicators (SQIs) into a management process in remediation using a scoring method. The scored SQIs are integrated into a soil quality index corresponding to 1 of 5 classes. SF Box is applied to 2 cases from Sweden (Kvillebäcken and Hexion), explicitly taking into consideration uncertainties in the results by means of Monte Carlo simulations. At both sites the generated soil quality indices corresponded to a medium soil performance (soil class 3) with a high certainty. The main soil constraints at both Kvillebäcken and Hexion were associated with biological activity in the soil, as soil organisms were unable to supply plant-available N. At the Kvillebäcken site the top layer had a content of coarse fragment (ø > 2 mm) higher than 35%, indicating plant rooting limitations. At the Hexion site, the soil had limited amount of organic matter, thus poor aggregate stability and nutrient cycling potential. In contrast, the soil at Kvillebäcken was rich in organic matter. The soils at both sites were capable of storing a sufficient amount of water for soil organisms between precipitation events. © 2014 SETAC.

40 CFR 60.1125 - What must I include in my siting analysis?

Code of Federal Regulations, 2010 CFR

2010-07-01

... waste combustion unit affects four areas: (1) Ambient air quality. (2) Visibility. (3) Soils. (4) Vegetation. (b) Include an analysis of alternatives for controlling air pollution that minimize potential...

Assessment of physical and chemical indicators of sandy soil quality for sustainable crop production

NASA Astrophysics Data System (ADS)

Lipiec, Jerzy; Usowicz, Boguslaw

2017-04-01

Sandy soils are used in agriculture in many regions of the world. The share of sandy soils in Poland is about 55%. The aim of this study was to assess spatial variability of soil physical and chemical properties affecting soil quality and crop yields in the scale of field (40 x 600 m) during three years of different weather conditions. The experimental field was located on the post glacial and acidified sandy deposits of low productivity (Szaniawy, Podlasie Region, Poland). Physical soil quality indicators included: content of sand, silt, clay and water, bulk density and those chemical: organic carbon, cation exchange capacity, acidity (pH). Measurements of the most soil properties were done at spring and summer each year in topsoil and subsoil layer in 150 points. Crop yields were evaluated in places close to measuring points of the soil properties. Basic statistics including mean, standard deviation, skewness, kurtosis minimal, maximal and correlations between the soil properties and crop yields were calculated. Analysis of spatial dependence and distribution for each property was performed using geostatistical methods. Mathematical functions were fitted to the experimentally derived semivariograms that were used for mapping the soil properties and crop yield by kriging. The results showed that the largest variations had clay content (CV 67%) and the lowest: sand content (5%). The crop yield was most negatively correlated with sand content and most positively with soil water content and cation exchange capacity. In general the exponential semivariogram models fairly good matched to empirical data. The range of semivariogram models of the measured indicators varied from 14 m to 250 m indicate high and moderate spatial variability. The values of the nugget-to-sill+nugget ratios showed that most of the soil properties and crop yields exhibited strong and moderate spatial dependency. The kriging maps allowed identification of low yielding sub-field areas that correspond with low soil organic carbon and cation exchange capacity and high content of sand. These areas are considered as management zones to improve crop productivity and soil properties responsible for soil quality and functions. We conclude that soil organic carbon, cation exchange capacity and pH should be included as indicators of soil quality in sandy soils. The study was funded by HORIZON 2020, European Commission, Programme H2020-SFS-2015-2: Soil Care for profitable and sustainable crop production in Europe, project No. 677407 (SoilCare, 2016-2021).

Soil organic carbon and nitrogen pools drive soil C-CO2 emissions from selected soils in Maritime Antarctica.

PubMed

Pires, C V; Schaefer, C E R G; Hashigushi, A K; Thomazini, A; Filho, E I F; Mendonça, E S

2017-10-15

The ongoing trend of increasing air temperatures will potentially affect soil organic matter (SOM) turnover and soil C-CO 2 emissions in terrestrial ecosystems of Maritime Antarctica. The effects of SOM quality on this process remain little explored. We evaluated (i) the quantity and quality of soil organic matter and (ii) the potential of C release through CO 2 emissions in lab conditions in different soil types from Maritime Antarctica. Soil samples (0-10 and 10-20cm) were collected in Keller Peninsula and the vicinity of Arctowski station, to determine the quantity and quality of organic matter and the potential to emit CO 2 under different temperature scenarios (2, 5, 8 and 11°C) in lab. Soil organic matter mineralization is low, especially in soils with low organic C and N contents. Recalcitrant C form is predominant, especially in the passive pool, which is correlated with humic substances. Ornithogenic soils had greater C and N contents (reaching to 43.15gkg -1 and 5.22gkg -1 for total organic carbon and nitrogen, respectively). C and N were more present in the humic acid fraction. Lowest C mineralization was recorded from shallow soils on basaltic/andesites. C mineralization rates at 2°C were significant lower than at higher temperatures. Ornithogenic soils presented the lowest values of C-CO 2 mineralized by g of C. On the other hand, shallow soils on basaltic/andesites were the most sensitive sites to emit C-CO 2 by g of C. With permafrost degradation, soils on basaltic/andesites and sulfates are expected to release more C-CO 2 than ornithogenic soils. With greater clay contents, more protection was afforded to soil organic matter, with lower microbial activity and mineralization. The trend of soil temperature increases will favor C-CO 2 emissions, especially in the reduced pool of C stored and protected on permafrost, or in occasional Histosols. Copyright © 2016 Elsevier B.V. All rights reserved.

Effect of land management on soil properties in flood irrigated citrus orchards in Eastern Spain

NASA Astrophysics Data System (ADS)

Morugán-Coronado, A.; García-Orenes, F.; Cerdà, A.

2015-01-01

Agricultural land management greatly affects soil properties. Microbial soil communities are the most sensitive and rapid indicators of perturbations in land use and soil enzyme activities are sensitive biological indicators of the effects of soil management practices. Citrus orchards frequently have degraded soils and this paper evaluates how land management in citrus orchards can improve soil quality. A field experiment was performed in an orchard of orange trees (Citrus Sinensis) in the Alcoleja Experimental Station (Eastern Spain) with clay-loam agricultural soils to assess the long-term effects of herbicides with inorganic fertilizers (H), intensive ploughing and inorganic fertilizers (P) and organic farming (O) on the soil microbial properties, and to study the relationship between them. Nine soil samples were taken from each agricultural management plot. In all the samples the basal soil respiration, soil microbial biomass carbon, water holding capacity, electrical conductivity, soil organic matter, total nitrogen, available phosphorus, available potassium, aggregate stability, cation exchange capacity, pH, texture, macronutrients (Na, Ca and Mg), micronutrients (Fe, Mn, Zn and Cu), calcium carbonate equivalent, calcium carbonate content of limestone and enzimatic activities (urease, dehydrogenase, β-glucosidase and acid phosphatase) were determined. The results showed a substantial level of differentiation in the microbial properties, which were highly associated with soil organic matter content. The management practices including herbicides and intensive ploughing had similar results on microbial soil properties. O management contributed to an increase in the soil biology quality, aggregate stability and organic matter content.

Hydrogeology and chemical quality of water and soil at Carroll Island, Aberdeen Proving Ground, Maryland

USGS Publications Warehouse

Tenbus, F.J.; Phillips, S.W.

1996-01-01

Carroll Island was used for open-air testing of chemical warfare agents from the late 1940's until 1971. Testing and disposal activities weresuspected of causing environmental contamination at 16 sites on the island. The hydrogeology and chemical quality of ground water, surface water, and soil at these sites were investigated with borehole logs, environmental samples, water-level measurements, and hydrologic tests. A surficial aquifer, upper confining unit, and upper confined aquifer were defined. Ground water in the surficial aquifer generally flows from the east-central part of the island toward the surface-water bodies, butgradient reversals caused by evapotranspiration can occur during dry seasons. In the confined aquifer, hydraulic gradients are low, and hydraulic head is affected by tidal loading and by seasonal pumpage from the west. Inorganic chemistry in the aquifers is affected by brackish-water intrusion from gradient reversals and by dissolution ofcarboniferous shell material in the confining unit.The concentrations of most inorganic constituents probably resulted from natural processes, but some concentrations exceeded Federal water-quality regulations and criteria. Organic compounds were detected in water and soil samples at maximum concentrations of 138 micrograms per liter (thiodiglycol in surface water) and 12 micrograms per gram (octadecanoic acid in soil).Concentrations of organic compounds in ground water exceeded Federal drinking-water regulations at two sites. The organic compounds that weredetected in environmental samples were variously attributed to natural processes, laboratory or field- sampling contamination, fallout from industrial air pollution, and historical military activities.

Visual assessment of soil structure quality in an agroextractivist system in Southeastern Amazonia

NASA Astrophysics Data System (ADS)

Fernanda Simões da Silva, Laura; Stuchi Boschi, Raquel; Ortega Gomes, Matheus; Cooper, Miguel

2016-04-01

Soil structure is considered a key factor in the functioning of soil, affecting its ability to support plant and animal life, and moderate environmental quality. Numerous methods are available to evaluate soil structure based on physical, chemical and biological indicators. Among the physical indicators, the attributes most commonly used are soil bulk density, porosity, soil resistance to penetration, tensile strength of aggregates, soil water infiltration, and available water. However, these methods are expensive and generally time costly for sampling and laboratorial procedures. Recently, evaluations using qualitative and semi-quantitative indicators of soil structure quality have gained importance. Among these methods, the method known as Visual Evaluation of Soil Structure (VESS) (Ball et al., 2007; Guimarães et al., 2011) can supply this necessity in temperate and tropical regions. The study area is located in the Piranheira Praialta Agroextrativist Settlement Project in the county of Nova Ipixuna, Pará, Brazil. Two toposequences were chosen, one under native forest and the other under pasture. Pits were opened in different landscape positions (upslope, midslope and downslope) for soil morphological, micromorphological and physical characterization. The use of the soil visual evaluation method (SVE) consisted in collecting an undisturbed soil sample of approximately 25 cm in length, 20 cm in width and 10 cm in depth. 12 soil samples were taken for each land use. The samples were manually fragmented, respecting the fracture planes between the aggregates. The SVE was done comparing the fragmented sample with a visual chart and scores were given to the soil structure. The categories that define the soil structure quality (Qe) vary from 1 to 5. Lower scores mean better soil structure. The final score calculation was done using the classification key of Ball et al. (2007) adapted by Guimarães (2011). A change in soil structure was observed between forest and pasture. The presence of layers of different depths, and size and shape of aggregates resulted in a lower Qe in the forest soils (Qe= 2,04 ±0,4), followed by the pasture (Qe= 3,09 ± 1,3). These results indicate certain degradation in the soil structure in the pasture. The variability of the soil structure in the forest samples was lower. The pasture samples presented a worse soil structure when compared to the forest, although their Qe values can be considered good.

Enhanced Representation of Soil NO Emissions in the Community Multiscale Air Quality (CMAQ) Model Version 5.0.2

NASA Technical Reports Server (NTRS)

Rasool, Quazi Z.; Zhang, Rui; Lash, Benjamin; Cohan, Daniel S.; Cooter, Ellen J.; Bash, Jesse O.; Lamsal, Lok N.

2016-01-01

Modeling of soil nitric oxide (NO) emissions is highly uncertain and may misrepresent its spatial and temporal distribution. This study builds upon a recently introduced parameterization to improve the timing and spatial distribution of soil NO emission estimates in the Community Multiscale Air Quality (CMAQ) model. The parameterization considers soil parameters, meteorology, land use, and mineral nitrogen (N) availability to estimate NO emissions. We incorporate daily year-specific fertilizer data from the Environmental Policy Integrated Climate (EPIC) agricultural model to replace the annual generic data of the initial parameterization, and use a 12km resolution soil biome map over the continental USA. CMAQ modeling for July 2011 shows slight differences in model performance in simulating fine particulate matter and ozone from Interagency Monitoring of Protected Visual Environments (IMPROVE) and Clean Air Status and Trends Network (CASTNET) sites and NO2 columns from Ozone Monitoring Instrument (OMI) satellite retrievals. We also simulate how the change in soil NO emissions scheme affects the expected O3 response to projected emissions reductions.

Field Scale Spatial Modelling of Surface Soil Quality Attributes in Controlled Traffic Farming

NASA Astrophysics Data System (ADS)

Guenette, Kris; Hernandez-Ramirez, Guillermo

2017-04-01

The employment of controlled traffic farming (CTF) can yield improvements to soil quality attributes through the confinement of equipment traffic to tramlines with the field. There is a need to quantify and explain the spatial heterogeneity of soil quality attributes affected by CTF to further improve our understanding and modelling ability of field scale soil dynamics. Soil properties such as available nitrogen (AN), pH, soil total nitrogen (STN), soil organic carbon (SOC), bulk density, macroporosity, soil quality S-Index, plant available water capacity (PAWC) and unsaturated hydraulic conductivity (Km) were analysed and compared among trafficked and un-trafficked areas. We contrasted standard geostatistical methods such as ordinary kriging (OK) and covariate kriging (COK) as well as the hybrid method of regression kriging (ROK) to predict the spatial distribution of soil properties across two annual cropland sites actively employing CTF in Alberta, Canada. Field scale variability was quantified more accurately through the inclusion of covariates; however, the use of ROK was shown to improve model accuracy despite the regression model composition limiting the robustness of the ROK method. The exclusion of traffic from the un-trafficked areas displayed significant improvements to bulk density, macroporosity and Km while subsequently enhancing AN, STN and SOC. The ability of the regression models and the ROK method to account for spatial trends led to the highest goodness-of-fit and lowest error achieved for the soil physical properties, as the rigid traffic regime of CTF altered their spatial distribution at the field scale. Conversely, the COK method produced the most optimal predictions for the soil nutrient properties and Km. The use of terrain covariates derived from light ranging and detection (LiDAR), such as of elevation and topographic position index (TPI), yielded the best models in the COK method at the field scale.

Impact of understory vegetation on soil carbon and nitrogen dynamic in aerially seeded Pinus massoniana plantations.

PubMed

Pan, Ping; Zhao, Fang; Ning, Jinkui; Zhang, Ling; Ouyang, Xunzhi; Zang, Hao

2018-01-01

Understory vegetation plays a vital role in regulating soil carbon (C) and nitrogen (N) characteristics due to differences in plant functional traits. Different understory vegetation types have been reported following aerial seeding. While aerial seeding is common in areas with serious soil erosion, few studies have been conducted to investigate changes in soil C and N cycling as affected by understory vegetation in aerially seeded plantations. Here, we studied soil C and N characteristics under two naturally formed understory vegetation types (Dicranopteris and graminoid) in aerially seeded Pinus massoniana Lamb plantations. Across the two studied understory vegetation types, soil organic C was significantly correlated with all measured soil N variables, including total N, available N, microbial biomass N and water-soluble organic N, while microbial biomass C was correlated with all measured variables except soil organic C. Dicranopteris and graminoid differed in their effects on soil C and N process. Except water-soluble organic C, all the other C and N variables were higher in soils with graminoids. The higher levels of soil organic C, microbial biomass C, total N, available N, microbial biomass N and water-soluble organic N were consistent with the higher litter and root quality (C/N) of graminoid vegetation compared to Dicranopteris. Changes in soil C and N cycles might be impacted by understory vegetation types via differences in litter or root quality.

Impact of understory vegetation on soil carbon and nitrogen dynamic in aerially seeded Pinus massoniana plantations

PubMed Central

Pan, Ping; Zhao, Fang; Ning, Jinkui; Ouyang, Xunzhi; Zang, Hao

2018-01-01

Understory vegetation plays a vital role in regulating soil carbon (C) and nitrogen (N) characteristics due to differences in plant functional traits. Different understory vegetation types have been reported following aerial seeding. While aerial seeding is common in areas with serious soil erosion, few studies have been conducted to investigate changes in soil C and N cycling as affected by understory vegetation in aerially seeded plantations. Here, we studied soil C and N characteristics under two naturally formed understory vegetation types (Dicranopteris and graminoid) in aerially seeded Pinus massoniana Lamb plantations. Across the two studied understory vegetation types, soil organic C was significantly correlated with all measured soil N variables, including total N, available N, microbial biomass N and water-soluble organic N, while microbial biomass C was correlated with all measured variables except soil organic C. Dicranopteris and graminoid differed in their effects on soil C and N process. Except water-soluble organic C, all the other C and N variables were higher in soils with graminoids. The higher levels of soil organic C, microbial biomass C, total N, available N, microbial biomass N and water-soluble organic N were consistent with the higher litter and root quality (C/N) of graminoid vegetation compared to Dicranopteris. Changes in soil C and N cycles might be impacted by understory vegetation types via differences in litter or root quality. PMID:29377926

Ranking factors affecting emissions of GHG from incubated agricultural soils.

PubMed

García-Marco, S; Ravella, S R; Chadwick, D; Vallejo, A; Gregory, A S; Cárdenas, L M

2014-07-01

Agriculture significantly contributes to global greenhouse gas (GHG) emissions and there is a need to develop effective mitigation strategies. The efficacy of methods to reduce GHG fluxes from agricultural soils can be affected by a range of interacting management and environmental factors. Uniquely, we used the Taguchi experimental design methodology to rank the relative importance of six factors known to affect the emission of GHG from soil: nitrate (NO 3 - ) addition, carbon quality (labile and non-labile C), soil temperature, water-filled pore space (WFPS) and extent of soil compaction. Grassland soil was incubated in jars where selected factors, considered at two or three amounts within the experimental range, were combined in an orthogonal array to determine the importance and interactions between factors with a L 16 design, comprising 16 experimental units. Within this L 16 design, 216 combinations of the full factorial experimental design were represented. Headspace nitrous oxide (N 2 O), methane (CH 4 ) and carbon dioxide (CO 2 ) concentrations were measured and used to calculate fluxes. Results found for the relative influence of factors (WFPS and NO 3 - addition were the main factors affecting N 2 O fluxes, whilst glucose, NO 3 - and soil temperature were the main factors affecting CO 2 and CH 4 fluxes) were consistent with those already well documented. Interactions between factors were also studied and results showed that factors with little individual influence became more influential in combination. The proposed methodology offers new possibilities for GHG researchers to study interactions between influential factors and address the optimized sets of conditions to reduce GHG emissions in agro-ecosystems, while reducing the number of experimental units required compared with conventional experimental procedures that adjust one variable at a time.

Assessment of exposure to heavy metals and health risks among residents near Tonglushan mine in Hubei, China.

PubMed

Cai, Li-Mei; Xu, Zhen-Cheng; Qi, Jian-Ying; Feng, Zhi-Zhou; Xiang, Ting-Sheng

2015-05-01

Heavy metal contamination due to mining activity is a global major concern because of its potential health risks to local inhabitants. In the present study, we investigated the levels of Cd, Cu, Pb and As in soil, crop, well water and fish samples collected from the vicinity of the Tonglushan mine in Hubei, China, and evaluated potential health risks among local residents. Results indicate that soils near the mine were heavily contaminated with Cd (2.59 mg kg(-1)), Cu (386 mg kg(-1)), Pb (120 mg kg(-1)) and As (35.4 mg kg(-1)), and exceeded the soil quality standard values of Cd and Cu contamination. The concentrations of Cd, Cu, Pb and As in crop samples grown in mine-affected soils were significantly higher than those of the reference soils. The concentrations of Cd and As in most vegetables grown in mine-affected soils exceeded the maximum allowable level (MAL). The Cd, Pb and As concentration in rice grain collected from mine-affected soils were 2.95, 1.85 and 2.07-fold higher than the MAL, respectively. The concentrations of Cd and As in fish muscle from the mine-affected area were above national MAL in 61% and 34% of analyzed samples, respectively. All measured heavy metals except Pb were significantly greater in well water in the mine-affected area than those in the reference areas. The average estimated daily intakes of Cd and As were beyond the provisional tolerable daily intake, respectively. The intake of rice was identified as a major contributor (⩾72%) to the estimated daily intake among the residents. Copyright © 2015 Elsevier Ltd. All rights reserved.

Ranking factors affecting emissions of GHG from incubated agricultural soils

PubMed Central

García-Marco, S; Ravella, S R; Chadwick, D; Vallejo, A; Gregory, A S; Cárdenas, L M

2014-01-01

Agriculture significantly contributes to global greenhouse gas (GHG) emissions and there is a need to develop effective mitigation strategies. The efficacy of methods to reduce GHG fluxes from agricultural soils can be affected by a range of interacting management and environmental factors. Uniquely, we used the Taguchi experimental design methodology to rank the relative importance of six factors known to affect the emission of GHG from soil: nitrate (NO3−) addition, carbon quality (labile and non-labile C), soil temperature, water-filled pore space (WFPS) and extent of soil compaction. Grassland soil was incubated in jars where selected factors, considered at two or three amounts within the experimental range, were combined in an orthogonal array to determine the importance and interactions between factors with a L16 design, comprising 16 experimental units. Within this L16 design, 216 combinations of the full factorial experimental design were represented. Headspace nitrous oxide (N2O), methane (CH4) and carbon dioxide (CO2) concentrations were measured and used to calculate fluxes. Results found for the relative influence of factors (WFPS and NO3− addition were the main factors affecting N2O fluxes, whilst glucose, NO3− and soil temperature were the main factors affecting CO2 and CH4 fluxes) were consistent with those already well documented. Interactions between factors were also studied and results showed that factors with little individual influence became more influential in combination. The proposed methodology offers new possibilities for GHG researchers to study interactions between influential factors and address the optimized sets of conditions to reduce GHG emissions in agro-ecosystems, while reducing the number of experimental units required compared with conventional experimental procedures that adjust one variable at a time. PMID:25177207

A preliminary test of estimating forest site quality using species composition in a southern Appalachian watershed

Treesearch

W. Henry McNab; David L. Loftis

2013-01-01

Characteristic arborescent communities of mesophytic or xerophytic species have long been recognized as indicative of forest site quality in the Southern Appalachians, where soil moisture availability is the primary environmental variable affecting productivity. But, a workable quantitative system of site classification based on species composition is not available. We...

Land-use types and soil chemical properties influence soil microbial communities in the semiarid Loess Plateau region in China

PubMed Central

Tian, Qin; Taniguchi, Takeshi; Shi, Wei-Yu; Li, Guoqing; Yamanaka, Norikazu; Du, Sheng

2017-01-01

Similar land-use types usually have similar soil properties, and, most likely, similar microbial communities. Here, we assessed whether land-use types or soil chemical properties are the primary drivers of soil microbial community composition, and how changes in one part of the ecosystem affect another. We applied Ion Torrent sequencing to the bacterial and fungal communities of five different land-use (vegetation) types in the Loess Plateau of China. We found that the overall trend of soil quality was natural forest > plantation > bare land. Dominant bacterial phyla consisted of Proteobacteria (42.35%), Actinobacteria (15.61%), Acidobacteria (13.32%), Bacteroidetes (8.43%), and Gemmatimonadetes (6.0%). The dominant fungi phyla were Ascomycota (40.39%), Basidiomycota (38.01%), and Zygomycota (16.86%). The results of Canonical Correspondence Analysis (CCA) and Redundancy Analysis (RDA) based on land-use types displayed groups according to the land-use types. Furthermore, the bacterial communities were mainly organized by soil organic carbon (SOC). The fungal communities were mainly related to available phosphorus (P). The results suggested that the changes of land use type generated changes in soil chemical properties, controlling the composition of microbial community in the semiarid Loess Plateau region. The microbial community could be an indicator for soil quality with respect to ecological restoration. PMID:28349918

Land-use types and soil chemical properties influence soil microbial communities in the semiarid Loess Plateau region in China

NASA Astrophysics Data System (ADS)

Tian, Qin; Taniguchi, Takeshi; Shi, Wei-Yu; Li, Guoqing; Yamanaka, Norikazu; Du, Sheng

2017-03-01

Similar land-use types usually have similar soil properties, and, most likely, similar microbial communities. Here, we assessed whether land-use types or soil chemical properties are the primary drivers of soil microbial community composition, and how changes in one part of the ecosystem affect another. We applied Ion Torrent sequencing to the bacterial and fungal communities of five different land-use (vegetation) types in the Loess Plateau of China. We found that the overall trend of soil quality was natural forest > plantation > bare land. Dominant bacterial phyla consisted of Proteobacteria (42.35%), Actinobacteria (15.61%), Acidobacteria (13.32%), Bacteroidetes (8.43%), and Gemmatimonadetes (6.0%). The dominant fungi phyla were Ascomycota (40.39%), Basidiomycota (38.01%), and Zygomycota (16.86%). The results of Canonical Correspondence Analysis (CCA) and Redundancy Analysis (RDA) based on land-use types displayed groups according to the land-use types. Furthermore, the bacterial communities were mainly organized by soil organic carbon (SOC). The fungal communities were mainly related to available phosphorus (P). The results suggested that the changes of land use type generated changes in soil chemical properties, controlling the composition of microbial community in the semiarid Loess Plateau region. The microbial community could be an indicator for soil quality with respect to ecological restoration.

Planting richness affects the recovery of vegetation and soil processes in constructed wetlands following disturbance

USGS Publications Warehouse

Means, Mary M.; Ahn, Changwoo; Noe, Gregory

2017-01-01

The resilience of constructed wetland ecosystems to severe disturbance, such as a mass herbivory eat-out or soil disturbance, remains poorly understood. In this study, we use a controlled mesocosm experiment to examine how original planting diversity affects the ability of constructed freshwater wetlands to recover structurally and functionally after a disturbance (i.e., aboveground harvesting and soil coring). We assessed if the planting richness of macrophyte species influences recovery of constructed wetlands one year after a disturbance. Mesocosms were planted in richness groups with various combinations of either 1, 2, 3, or 4 species (RG 1–4) to create a gradient of richness. Structural wetland traits measured include morphological regrowth of macrophytes, soil bulk density, soil moisture, soil %C, and soil %N. Functional wetland traits measured include above ground biomass production, soil potential denitrification, and soil potential microbial respiration. Total mesocosm cover increased along the gradient of plant richness (43.5% in RG 1 to 84.5% in RG 4) in the growing season after the disturbance, although not all planted individuals recovered. This was largely attributed to the dominance of the obligate annual species. The morphology of each species was affected negatively by the disturbance, producing shorter, and fewer stems than in the years prior to the disturbance, suggesting that the communities had not fully recovered one year after the disturbance. Soil characteristics were almost uniform across the planting richness gradient, but for a few exceptions (%C, C:N, and non-growing season soil moisture were higher slightly in RG 2). Denitrification potential (DEA) increased with increasing planting richness and was influenced by the abundance and quality of soil C. Increased open space in unplanted mesocosms and mesocosms with lower species richness increased labile C, leading to higher C mineralization rates.

Differences in SOM decomposition and temperature sensitivity among soil aggregate size classes in a temperate grasslands.

PubMed

Wang, Qing; Wang, Dan; Wen, Xuefa; Yu, Guirui; He, Nianpeng; Wang, Rongfu

2015-01-01

The principle of enzyme kinetics suggests that the temperature sensitivity (Q10) of soil organic matter (SOM) decomposition is inversely related to organic carbon (C) quality, i.e., the C quality-temperature (CQT) hypothesis. We tested this hypothesis by performing laboratory incubation experiments with bulk soil, macroaggregates (MA, 250-2000 μm), microaggregates (MI, 53-250 μm), and mineral fractions (MF, <53 μm) collected from an Inner Mongolian temperate grassland. The results showed that temperature and aggregate size significantly affected on SOM decomposition, with notable interactive effects (P<0.0001). For 2 weeks, the decomposition rates of bulk soil and soil aggregates increased with increasing incubation temperature in the following order: MA>MF>bulk soil >MI(P <0.05). The Q10 values were highest for MA, followed (in decreasing order) by bulk soil, MF, and MI. Similarly, the activation energies (Ea) for MA, bulk soil, MF, and MI were 48.47, 33.26, 27.01, and 23.18 KJ mol-1, respectively. The observed significant negative correlations between Q10 and C quality index in bulk soil and soil aggregates (P<0.05) suggested that the CQT hypothesis is applicable to soil aggregates. Cumulative C emission differed significantly among aggregate size classes (P <0.0001), with the largest values occurring in MA (1101 μg g-1), followed by MF (976 μg g-1) and MI (879 μg g-1). These findings suggest that feedback from SOM decomposition in response to changing temperature is closely associated withsoil aggregation and highlights the complex responses of ecosystem C budgets to future warming scenarios.

Soil and solid poultry waste nutrient management and water quality.

PubMed

Chapman, S L

1996-07-01

Concerns about the impacts of nitrogen, phosphorus, and pathogens on surface and ground water quality has forced the poultry industry to implement voluntary waste management guidelines for use by growers. In some states, animal waste guidelines are being enforced by regulatory agencies. Strategies that growers may use to properly dispose of poultry waste include: 1) local land application as a fertilizer; 2) offsite marketing for use as a fertilizer or soil amendment, feed additive, or energy source; and 3) chemical additives that will immobilize nitrogen and phosphorus in the manure or litter. If properly followed, these and other innovative strategies should be adequate to protect surface and ground water quality without adversely affecting the economics of poultry production.

Soil erosion-runoff relationships: insights from laboratory studies

NASA Astrophysics Data System (ADS)

Mamedov, Amrakh; Warrington, David; Levy, Guy

2016-04-01

Understanding the processes and mechanisms affecting runoff generation and subsequent soil erosion in semi-arid regions is essential for the development of improved soil and water conservation management practices. Using a drip type laboratory rain simulator, we studied runoff and soil erosion, and the relationships between them, in 60 semi-arid region soils varying in their intrinsic properties (e.g., texture, organic matter) under differing extrinsic conditions (e.g., rain properties, and conditions prevailing in the field soil). Both runoff and soil erosion were significantly affected by the intrinsic soil and rain properties, and soil conditions within agricultural fields or watersheds. The relationship between soil erosion and runoff was stronger when the rain kinetic energy was higher rather than lower, and could be expressed either as a linear or exponential function. Linear functions applied to certain limited cases associated with conditions that enhanced soil structure stability, (e.g., slow wetting, amending with soil stabilizers, minimum tillage in clay soils, and short duration exposure to rain). Exponential functions applied to most of the cases under conditions that tended to harm soil stability (e.g., fast wetting of soils, a wide range of antecedent soil water contents and rain kinetic energies, conventional tillage, following biosolid applications, irrigation with water of poor quality, consecutive rain simulations). The established relationships between runoff and soil erosion contributed to a better understanding of the mechanisms governing overland flow and soil loss, and could assist in (i) further development of soil erosion models and research techniques, and (ii) the design of more suitable management practices for soil and water conservation.

Assessment of soil hydrology variability of a new weighing lysimeter facility

NASA Astrophysics Data System (ADS)

Brown, S. E.; Wagner-Riddle, C.; Berg, A. A.

2017-12-01

Diversifying annual crop rotations is a strategy that mimics natural ecosystems and is postulated to increase agricultural resilience to climate change, soil quality and provision of soil ecosystem services. However, diverse cropping systems could increase soil mineral N levels and lead to greater leaching and/or N2O emissions; which raises the questions: (i) are diverse cropping systems actually beneficial for air and water quality? (ii) what are the trade-offs between soil, water, and air quality upon implementing a diverse cropping rotation? It can be difficult to fully evaluate the interactions between the two N-pollution pathways simultaneously in traditional field studies as drainage is largely unconstrained. Weighing lysimeters solve this issue by providing a closed system to measure N outputs via drainage and soil gas fluxes. A set of 18 weighting lysimeters were installed in Elora, Ontario, Canada in May 2016, to establish a long-term study of N-leaching and greenhouse gas emission from traditional and diverse cropping rotations for two different soil types. Each lysimeter is equipped with an automated chamber for continuous measurement of soil N2O and CO2 fluxes. A full characterization of variations of physical properties that may affect GHG emissions and N-leaching (e.g., soil temperature, moisture, drainage and evapotranspiration rates) amongst the lysimeters is required prior to application and assessment of the management treatments. Novel techniques such as wavelet analysis is required as standard statistical analyses are not applicable to the time series data. A full description of the lysimeters will be presented along with results of the characterization.

What's in our soil?: how soil pollution affects earthworm movement patterns

NASA Astrophysics Data System (ADS)

Whitmore, T.

2017-12-01

Earthworms are an important member of many ecosystems because they contribute to soil quality and are a major food source for many organisms. In this project, we assessed the impacts soil pollution has on the burrowing patterns of earthworms. In each experiment, we introduced 10 earthworms to a unique pollutant and let them equilibrate for up to a week. The results indicated that earthworms migrate towards the introduced liquid regardless of its impact on them. The liquid pollutants introduced seemed to attract the earthworms. This can have harmful consequences, especially in the case of the motor oil, which killed multiple worms.

Mapping Erosion Risk in California's Rangelands Using the Universal Soil Loss Equation (USLE)

NASA Astrophysics Data System (ADS)

Salls, W. B.; O'Geen, T. T.

2015-12-01

Soil loss constitutes a multi-faceted problem for agriculture: in addition to reducing soil fertility and crop yield, it compromises downstream water quality. Sediment itself is a major issue for aquatic ecosystems, but also serves as a vector for transporting nutrients, pesticides, and pathogens. Rangelands are thought to be a contributor to water quality degradation in California, particularly in the northern Coast Range. Though total maximum daily loads (TMDLs) have been imposed in some watersheds, and countless rangeland water quality outreach activities have been conducted, the connection between grazing intensity recommendations and changes in water quality is poorly understood at the state level. This disconnect gives rise to poorly informed regulations and discourages adoption of best management practices by ranchers. By applying the Universal Soil Loss Equation (USLE) at a statewide scale, we highlighted areas most prone to erosion. We also investigated how two different grazing intensity scenarios affect modeled soil loss. Geospatial data layers representing the USLE parameters—rainfall erosivity, soil erodibility, slope length and steepness, and cover—were overlaid to model annual soil loss. Monitored suspended sediment data from a small North Coast watershed with grazing as the predominant land use was used to validate the model. Modeled soil loss values were nearly one order of magnitude higher than monitored values; average soil loss feeding the downstream-most site was modeled at 0.329 t ha-1 yr-1, whereas storm-derived sediment passing the site over two years was calculated to be 0.037 t ha-1 yr-1. This discrepancy may stem from the fact that the USLE models detached sediment, whereas stream monitoring reflects sediment detached and subsequently transported to the waterway. Preliminary findings from the statewide map support the concern that the North Coast is particularly at risk given its combination of intense rain, erodible soils, and relatively steep terrain, though there is a fair degree of variability statewide.

Heavy metals in soils and sediments from Dongting Lake in China: occurrence, sources, and spatial distribution by multivariate statistical analysis.

PubMed

Zhang, Yaxin; Tian, Ye; Shen, Maocai; Zeng, Guangming

2018-05-01

Heavy metal contamination in soils/sediments and its impact on human health and ecological environment have aroused wide concerns. Our study investigated 30 samples of soils and sediments around Dongting Lake to analyze the concentration of As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn in the samples and to distinguish the natural and anthropogenic sources. Also, the relationship between heavy metals and the physicochemical properties of samples was studied by multivariate statistical analysis. Concentration of Cd at most sampling sites were more than five times that of national environmental quality standard for soil in China (GB 15618-1995), and Pb and Zn levels exceeded one to two times. Moreover, Cr in the soil was higher than the national environmental quality standards for one to two times while in sediment was lower than the national standard. The investigation revealed that the accumulations of As, Cd, Mn, and Pb in the soils, and sediments were affected apparently by anthropogenic activities; however, Cr, Fe, and Ni levels were impacted by parent materials. Human activities around Dongting Lake mainly consisted of industrial activities, mining and smelting, sewage discharges, fossil fuel combustion, and agricultural chemicals. The spatial distribution of heavy metal in soil followed the rule of geographical gradient, whereas in sediments, it was significantly affected by the river basins and human activities. The result of principal component analysis (PCA) demonstrated that heavy metals in soils were associated with pH and total phosphorus (TP), while in sediments, As, Cr, Fe, and Ni were closely associated with cation exchange capacity (CEC) and pH, where Pb, Zn, and Cd were associated with total nitrogen (TN), TP, total carbon (TC), moisture content (MC), soil organic matter (SOM), and ignition lost (IL). Our research provides comprehensive approaches to better understand the potential sources and the fate of contaminants in lakeshore soils and sediments.

Tree specie effects on soil microbial community composition and greenhouse gases emissions in a Mediterranean ecotone forest

NASA Astrophysics Data System (ADS)

Fernandez, Maria Jose; Ortiz, Carlos; Kitzler, Barbara; Curiel, Jorge; Rubio, Agustin

2016-04-01

Over recent decades in the Iberian Peninsula, altitudinal shifts from Pinus sylvestris L. to Quercus pyrenaica Willd species has been observed as a consequence of Global Change, meaning changes in temperature, precipitation, land use and forestry. The forest conversion from pine to oak can alter the litter quality and quantity provided to the soil and thereby the soil microbial community composition and functioning. Since soil microbiota plays an important role in organic matter decomposition, and this in turn is key in biogeochemical cycles and forest ecosystems productivity, the rate in which forests produce and consume greenhouse gases can be also affected by changes in forest composition. In other words, changes in litter decomposition will ultimately affect downstream carbon and nitrogen dynamics although this impact is uncertain. In order to predict changes in carbon and nitrogen stocks in Global Change scenarios, it is necessary to deepen the impact of vegetation changes on soil microbial communities, litter decomposition dynamics (priming effect) and the underlying interactions between these factors. To test this, we conducted a full-factorial transplant microcosms experiment mixing both fresh soils and litter from Pyrenean oak, Scots pine and mixed stands collected inside their transitional area in Central Spain. The microcosms consisted in soil cylinders inside Kilner jars used as chambers inside an incubator. In this experiment, we investigated how and to what extent the addition of litter with different quality (needles, oak leaves and mixed needles-leaves) to soil inoculums with contrasting soil microbiota impact on (i) soil CO2, NO, N2O and CH4 efflux rates, (ii) total organic carbon and nitrogen and (iii) dissolved organic carbon and nitrogen. Furthermore, we assessed if these responses were controlled by changes in the microbial community structure using the PLFA analyses prior and after the incubation period of 54 days.

Cover crops and crop residue management under no-till systems improve soils and environmental quality

NASA Astrophysics Data System (ADS)

Kumar, Sandeep; Wegner, Brianna; Vahyala, Ibrahim; Osborne, Shannon; Schumacher, Thomas; Lehman, Michael

2015-04-01

Crop residue harvest is a common practice in the Midwestern USA for the ethanol production. However, excessive removal of crop residues from the soil surface contributes to the degradation of important soil quality indicators such as soil organic carbon (SOC). Addition of a cover crop may help to mitigate these negative effects. The present study was set up to assess the impacts of corn (Zea mays L.) residue removal and cover crops on various soil quality indicators and surface greenhouse gas (GHG) fluxes. The study was being conducted on plots located at the North Central Agricultural Research Laboratory (NCARL) in Brookings, South Dakota, USA. Three plots of a corn and soybean (Glycine max (L.) Merr.) rotation under a no-till (NT) system are being monitored for soils and surface gas fluxes. Each plot has three residue removal (high residue removal, HRR; medium residue removal, MRR; and low residue removal, LRR) treatments and two cover crops (cover crops and no cover crops) treatments. Both corn and soybean are represented every year. Gas flux measurements were taken weekly using a closed static chamber method. Data show that residue removal significantly impacted soil quality indicators while more time was needed for an affect from cover crop treatments to be noticed. The LRR treatment resulted in higher SOC concentrations, increased aggregate stability, and increased microbial activity. The LRR treatment also increased soil organic matter (SOM) and particulate organic matter (POM) concentrations. Cover crops used in HRR (high corn residue removal) improved SOC (27 g kg-1) by 6% compared to that without cover crops (25.4 g kg-1). Cover crops significantly impacted POM concentration directly after the residue removal treatments were applied in 2012. CO2 fluxes were observed to increase as temperature increased, while N2O fluxes increased as soil moisture increased. CH4 fluxes were responsive to both increases in temperature and moisture. On average, soils under cover crop management had lower N2O fluxes than soils that did not have a cover crop. Results from this study concluded that it is important to allow crop residues to return to the soil as they help to improve soil quality indicators. The presence of cover crops also will contribute to the improvement of these indicators once established and may help mitigate greenhouse gas emissions.

Engineering salt-tolerant Brassica plants: characterization of yield and seed oil quality in transgenic plants with increased vacuolar sodium accumulation.

PubMed

Zhang, H X; Hodson, J N; Williams, J P; Blumwald, E

2001-10-23

Transgenic Brassica napus plants overexpressing AtNHX1, a vacuolar Na(+)/H(+) antiport from Arabidopsis thaliana, were able to grow, flower, and produce seeds in the presence of 200 mM sodium chloride. Although the transgenic plants grown in high salinity accumulated sodium up to 6% of their dry weight, growth of the these plants was only marginally affected by the high salt concentration. Moreover, seed yields and the seed oil quality were not affected by the high salinity of the soil. Our results demonstrate the potential use of these transgenic plants for agricultural use in saline soils. Our findings, showing that the modification of a single trait significantly improved the salinity tolerance of this crop plant, suggest that with a combination of breeding and transgenic plants it could be possible to produce salt-tolerant crops with far fewer target traits than had been anticipated.

Sustainable remediation of mercury contaminated soils by thermal desorption.

PubMed

Sierra, María J; Millán, Rocio; López, Félix A; Alguacil, Francisco J; Cañadas, Inmaculada

2016-03-01

Mercury soil contamination is an important environmental problem that needs the development of sustainable and efficient decontamination strategies. This work is focused on the application of a remediation technique that maintains soil ecological and environmental services to the extent possible as well as search for alternative sustainable land uses. Controlled thermal desorption using a solar furnace at pilot scale was applied to different types of soils, stablishing the temperature necessary to assure the functionality of these soils and avoid the Hg exchange to the other environmental compartments. Soil mercury content evolution (total, soluble, and exchangeable) as temperature increases and induced changes in selected soil quality indicators are studied and assessed. On total Hg, the temperature at which it is reduced until acceptable levels depends on the intended soil use and on how restrictive are the regulations. For commercial, residential, or industrial uses, soil samples should be heated to temperatures higher than 280 °C, at which more than 80 % of the total Hg is released, reaching the established legal total Hg level and avoiding eventual risks derived from high available Hg concentrations. For agricultural use or soil natural preservation, conversely, maintenance of acceptable levels of soil quality limit heating temperatures, and additional treatments must be considered to reduce available Hg. Besides total Hg concentration in soils, available Hg should be considered to make final decisions on remediation treatments and potential future uses. Graphical Abstract Solar energy use for remediation of soils affected by mercury.

Main Parameters of Soil Quality and it's Management Under Changing Climate

NASA Astrophysics Data System (ADS)

László Phd, M., ,, Dr.

2009-04-01

Reviewing Paper Introduction: Malcolm summarised the topic of soil quality and it's management in a well synthetized form in 2000. So, the soils are fundamental to the well-being and productivity of agricultural and natural ecosystems. Soil quality is a concept being developed to characterize the usefulness and health of soils. Soil quality includes soil fertility, potential productivity, contaminant levels and their effects, resource sustainability and environmental quality. A general definition of soil quality is the degree of fitness of a soil for a specific use. The existence of multiple definitions suggests that the soil quality concept continues to evolve (Kádár, 1992; Várallyay, 1992, 1994, 2005; Németh, 1996; Malcolm, 2000; Márton, 2005; Márton et al. 2007). Recent attention has focused on the sustainability of human uses of soil, based on concerns that soil quality may be declining (Boehn and Anderson, 1997). We use sustainable to mean that a use or management of soil will sustain human well-being over time. Lal (1995) described the land resources of the world (of which soil is one component) as "finite, fragile, and nonrenewable," and reported that only about 22% (3.26 billion ha) of the total land area on the globe is suitable for cultivation and at present, only about 3% (450 million ha) has a high agricultural production capacity. Because soil is in large but finite supply, and some soil components cannot be renewed within a human time frame, the condition of soils in agriculture and the environment is an issue of global concern (Howard, 1993; FAO, 1997). Concerns include soil losses from erosion, maintaining agricultural productivity and system sustainability, protecting natural areas, and adverse effects of soil contamination on human health (Haberern, 1992; Howard, 1993; Sims et al., 1997). Parr et al. (1992) state, "...soil degradation is the single most destructive force diminishing the world's soil resource base." Soil quality guidelines are intended to protect the ability of ecosystems to function properly (Kádár, 1992; Várallyay, 1992, 1994, 2005; Cook and Hendershot, 1996; Németh, 1996; Malcolm, 2000; Márton, 2005; Márton et al. 2007). The Hungarian Ministry of Environment and Water (HMEW, 2004) suggests that the Hungarian Regions should adopt a national policy "...that seeks to conserve and enhance soil quality...". Useful evaluation of soil quality requires agreement about why soil quality is important, how it is defined, how it should be measured, and how to respond to measurements with management, restoration, or conservation practices. Because determining soil quality requires one or more value judgments and because we have much to learn about soil, these issues are not easily addressed (Várallyay, 1992, 1994, 2005; Cook and Hendershot, 1996; Németh, 1996; Malcolm, 2000). Definitions of soil quality have been based both on human uses of soil and on the functions of soil within natural and agricultural ecosystems. For purposes of this work, we are showing soil quality within the context of managed agricultural ecosystems. To many in agriculture and agricultural research, productivity is analogous to soil quality. Maintaining soil quality is also a human health concern because air, groundwater and surface water consumed by humans can be adversely affected by mismanaged and contaminated soils, and because humans may be exposed to contaminated soils in residential areas (Kádár, 1992; Várallyay, 2005; Cook and Hendershot, 1996; Németh, 1996; Malcolm, 2000; Márton et al. 2007). Contamination may include heavy metals, toxic elements, excess nutrients, volatile and nonvolatile organics, explosives, radioactive isotopes and inhalable fibers (Sheppard et al., 1992; Cook and Hendershot, 1996). Soil quality is not determined by any single conserving or degrading process or property, and soil has both dynamic and relatively static properties that also vary spatially (Carter et al., 1997). Gregorich et al. (1994) state that "soil quality is a composite measure of both a soil's ability to function and how well it functions, relative to a specific use." Increasingly, contemporary discussion of soil quality includes the environmental cost of production and the potential for reclamation of degraded soils (Várallyay, 2005). Reasons for assessing soil quality in an agricultural or managed system may be somewhat different than reasons for assessing soil quality in a natural ecosystem. In an agricultural context, soil quality may be managed, to maximize production without adverse environmental effect, while in a natural ecosystem, soil quality may be observed, as a baseline value or set of values against which future changes in the system may be compared (Várallyay, 1994; Cook and Hendershot, 1996; Németh, 1996; Malcolm, 2000; Márton et al. 2007). Soil quality has historically been equated with agricultural productivity, and thus is not a new idea. Soil conservation practices to maintain soil productivity are as old as agriculture itself, with documentation dating to the Roman Empire (Jenny, 1961). The Storie Index (Storie, 1932) and USDA Land Capability Classification (Klingebiel and Montgomery, 1973) were developed to separate soils into different quality classes. Soil quality is implied in many decisions farmers make about land purchases and management, and in the economic value rural assessors place on agricultural land for purposes of taxation. Beginning in the 1930s, soil productivity ratings were developed in the United States and elsewhere to help farmers select crops and management practices that would maximize production and minimize erosion or other adverse environmental effects (Huddleston, 1984). These rating systems are important predecessors of recent attempts to quantitatively assess soil quality. In the 1970s, attempts were made to identify and protect soils of the highest productive capacity by defining "prime agricultural lands" (Miller, 1979). An idea related to soil quality is "carrying capacity". Carrying capacity is the number of individuals that can be supported in a given area (Budd, 1992). Soils with high productivity have high carrying capacity, and are considered to be high quality. Sustainability implies that a system does not exceed its carrying capacity over time. Recent attempts to define soil quality and develop indices to measure it have many of the properties of the earlier soil productivity ratings (Doran and Jones, 1996; Snakin et al., 1996; Seybold et al., 1997). Cox (1995) calls for national goals for soil quality that "... recognize the inherent links between soil, water and air quality." Haberern (1992) suggests that the decade of the 1990s is the time to study the soil as we have recognized and studied air quality and water quality in the preceding two decades. Air and water quality standards are generally based on maximum allowable concentrations of materials hazardous to human health. They are specified and enforced by regulators according to public uses of these resources. The result is that changes in air and water quality are now monitored to protect human health. With few exceptions, soil quality standards have not been set, nor have regulations been created regarding maintenance of soil quality (Várallyay, 2005; Cook and Hendershot, 1996; Malcolm, 2000; Márton et al. 2007). To the extent that soil has been the disposal site of hazardous wastes, as well as a pathway by which contamination or other applied chemicals may present a human health risk, sporadic 40 regulations of soil quality (in terms of contamination) does exist in the 27 European Union (EU) countries for not just new ones but an estimated 30 000 existing chemicals, today. These regulations are in the form of laws regulating hazardous waste, toxic substances, and pesticides. However, these standards are often contradictory, inconsistent with each other and with current methods of assessing risk. For example, in the United States, federal regulations supporting CERCLA (40 CFR) is a list of "hazardous substances" and the levels in various media (e.g., soil, water) to which the Environmental Protection Agency (EPA) must respond with a cleanup effort. However, EPA has fielded considerable controversy about contaminant levels and chemical forms that legitimately constitute a human health risk. Target cleanup levels have also been subject to debate and legislation. Soil quality assessment requires definition of a "clean" soil (Sims et al., 1997). From this point of view, good quality soil has been defined as posing "...no harm to any normal use by humans, plants or animals; not adversely affecting natural cycles or functions; and not contaminating other components of the environment" (Moen, 1988). The parallel to air and water quality is easy to draw on a conceptual level, but designation of soil quality standards is significantly complicated by soil variability and heterogeneity (Smith et al., 1993). Among the authors (Merker, 1956; Odell et al. 1984; Johnston et al., 1986; Reganold et al., 1990; Granatstein and Bezdicek, 1992; Kádár, 1992; Beke et al., 1994; Jenkinson et al., 1994; Schjenning et al., 1994; Murata et al., 1995; Biederbeck et al., 1996; Lindert et al., 1996; Romig et al., 1995; Warkentin, 1995; Carter et al., 1997; Gerzabeck et al., 1997; Seybold et al., 1997; Malcolm, 2000; Várallyay, 2005) and organizations defining soil quality are Larson and Pierce (1991), Karlen et al. (1997). The next section reviews some of the definitions and soil characteristics used to define soil quality. The reader should understand that the definition of soil quality and selection of soil characteristics needed to quantify soil quality are continuing to evolve. For example, Bouma (1989) recognized that an essential problem with definitions that produce carefully limited suitability classes is that empirical decisions must be made to separate the classes along what is essentially a continuum. That is, if soil organic matter is part of a soil quality definition, where on the continuum of soil organic matter content does one draw the line between a high quality and low quality soil? Does high organic matter content always indicate high soil quality? These are non-trivial questions under discussion by the soil science community. Carter et al. (1997) suggest a framework for evaluating soil quality that includes: 1. describing each soil function on which quality is to be based, 2. selecting soil characteristics or properties that influence the capacity of the soil to provide each function, 3. choosing indicators of characteristics that can be measured, and 4. using methods that provide accurate measurement of those indicators. The following soil functions appear frequently in the soil science literature: 1. soil maintains biological activity/productivity (Karlen et al., 1997), serves as medium for plant/crop growth (Arshad and Coen, 1992), supports plant productivity/yield (Arshad and Coen, 1992), supports human/animal health (Karlen et al., 1997); 2. partitions and regulates water/ solute flow through environment (Larson and Pierce, 1991; Arshad and Coen, 1992); 3. serves as an environmental buffer/filter (Larson and Pierce, 1991), maintains environmental quality (Arshad and Ccen, 1992); 4. cycles nutrients, water, energy and other elements through the biosphere (Anderson and Gregorich, 1984). Clearly, these functions are interrelated. Later in this chapter, discussion focuses on the first and third functions (productivity and environmental buffering) as encompassing those aspects of soil quality most debated in the literature. Larson and Pierce (1991) defined soil quality as "the capacity of a soil to function within the ecosystem boundaries and interact positively with the environment external to that ecosystem." Three soil functions are considered essential: provide a medium for plant growth, regulate and partition waterllow through the environment, and serve as an effective environmental filter. Arshad and Coen (1992) define soil quality as "the sustaining capability of a soil to accept, store and recycle water, minerals and energy for production of crops at optimum levels while preserving a healthy environment." They discuss terrain, climate and hydrology as site factors that contribute to soil quality and suggest that socioeconomic factors such as land use, operator and management should be included in a soil quality analysis. This approach is consistent with the FAO approach to land quality analysis (FAO, 1997). Karlen et al. (1992) define soil quality as "the ability of the soil to serve as a natural medium for the growth of plants that sustain human and animal life." Their definition is based on the role of soil quality in the long-term productivity of soil and maintenance of environmental quality. Doran and Parkin (1994) defined soil quality as "the capacity of a soil to function within ecosystem boundaries to sustain biological productivity, maintain environmental quality, and promote plant and animal health." Gregorich et al. (1994) define soil quality as "a composite measure of both a soil's ability to function and how well it functions relative to a specific use" or "the degree of fitness of a soil for a specific use." The Soil Science Society of America Ad Hoc Committee on Soil Health proposed that soil quality is "the capacity of a specific kind of soil to function, within natural or managed ecosystem boundaries, to sustain plant and animal productivity, maintain or enhance water and air quality, and support human health and habitation" (Karlen et al., 1997). This definition requires that five functions must be evaluated to describe soil quality: 1. sustaining biological activity, diversity, and productivity; 2. regulating and partitioning water and solute flow; 3. filtering, buffering, degrading, immobilizing and detoxifying organic and inorganic materials, including industrial and municipal byproducts and atmospheric deposition; 4. storing and cycling nutrients and other elements within the earth's biosphere; and 5. providing support of socioeconomic structures and protection for archeological treasures associated with human habitation. No soil is likely to successfully provide all of these functions, some of which occur in natural ecosystems and some of which are the result of human modification. We can summarize by saying that soil quality depends on the extent to which soil functions to benefit humans. Thus, for food production or mediation of contamination, soil quality means the extent to which a soil fulfills the role we have defined for it. Within agriculture, high quality equates to maintenance of high productivity without significant soil or environmental degradation. The Glossary of Soil Science terms produced by the Soil Science Society of America (1996) states that soil quality is an inherent attribute of a soil that is inferred from soil characteristics or indirect observations. To proceed from a dictionary definition to a measure of soil quality, a minimum dataset (MDS) of soil characteristics that represents soil quality must be selected and quantified (Papendick et al., 1995). The MDS may include biological, chemical or physical soil characteristics [Organic matter (OM), Aggregation (A), Bulk density (BD), Depth to hardpan (DH), Electrical conductivity (EC), Fertility (F), Respiration (R), pH, Soil test (ST), Yield (Y), Infiltration (I), Mineralizable nitrogen potential (MNP), Water holding capacity (WHC)]. For agriculture, the measurement of properties should lead to a relatively simple and accurate way to rank soils based on potential plant production without soil degradation. Unfortunately, commonly identified soil quality parameters may not correlate well with yield (Reganold, 1988). In the next section, we consider these four points concerning the selection and quantification of soil characteristics: 1. soil characteristics may be desirable or undesirable, 2. soil renewability involves judgment of the extent to which soil characteristics can be controlled or managed, 3. rates of change in soil characteristics vary, and 4. there may be significant temporal or spatial variation in soil characteristics. Components of soil quality definitions may include desirable and undesirable characteristics. Desirable soil characteristics may either be the presence of a property that benefits soil productivity and/or other important soil functions, or the absence of a property that is detrimental to these functions. A soil characteristic may include a range of values that contributes positively to quality and a range that contributes negatively. Soil pH, for example, may be a positive or negative characteristic depending on its value. Larson and Pierce (1991) suggest that ranges of property values can be defined as optimal, suboptimal or superoptimal. A pH range of 6 to 7.5 is optimal for production of most crops. Outside of this range, pH is suboptimal and soil quality is lower than at the optimal pH range. The complexity of the soil quality concept is illustrated by the fact that the choice of optimal pH range is crop or use dependent. Letey (1985) suggested that identification of a range of water content that is nonlimiting to plant productivity might be a good way of assessing the collective effect of soil physical characteristics that contribute to crop productivity. For soils of decreasing quality, the width of the nonlimiting water range decreases. Undesirable soil characteristics may be either the presence of contaminants or a range of values of soil characteristics that contribute negatively to soil quality. The presence of chemicals that inhibit plant root growth or the absence of nutrients that result in low yields or poor crop quality are examples of undesirable soil characteristics that lower soil quality. The extent to which soil is viewed as a renewable resource shapes our approach to soil quality. "Soil" in this context is the natural, three-dimensional, horizonated individual, not something created by earth moving machinery. For the purpose of assessing human impact on sustainability of soil quality, it may be appropriate to use only those soil properties that are slowly or nonrenewable. Shorter term assessments may be based on those properties that change rapidly and are subject to easy management. Willis and Evans (1977) argued that soil is not renewable over the short term based on studies that suggest that 30 to more than 1,000 years are required to develop 25 mm of surface soil from parent material by natural processes. Jenny (1980) also argued that soil is not renewable over the time scale to which humans relate. Howard (1993) suggests defining soil quality based on undisturbed natural soils and to set quality standards based on changes in soils which cannot be reversed naturally or by ecological approaches. The renewability of soil depends on the soil property considered. For example, once soil depth is reduced by wind or water erosion so that it is too shallow to support crops, it is not renewable within a human or management time frame. Some important soil characteristics are slowly renewable. Organic matter, most nutrients and some physical properties may be renewed through careful long-term management. Certain chemical properties (pH, salinity, N, P, K content) may be altered to a more satisfactory range for agriculture within a growing season or two, while removal of unwanted chemicals may take much longer. No soil property is permanent, but rates and frequency of change vary widely among properties. Soil properties also vary with ecosystem, arguably depending most on climate. In rangelands, for example, temporal variability is high and relatively unpredictable due to the strong dependence of soil properties on soil wetness (Herrick and Whitford, 1995). Variability in soil wetness is not restricted to rangelands and may be an especially important determinant of microbial community structure and function in both irrigated and rainfed agricultural systems. Arnold et al. (1990) suggest that changes in soil properties can be nonsystematic, periodic, or trend. Nonsystematic changes are short term and unpredictable. Periodic are predictable and trend changes tend to be in one direction over time. Carter et al. (1997) distinguish between dynamic soil properties that are most subject to change through human use and are strongly influenced by agronomic practices, and intrinsic or static properties that are not subject to rapid change or management. Examples of dynamic soil characteristics are the size, membership, distribution, and activity of a soil's microbiological community; the soil solution composition, pH, and nutrient ion concentrations, and the exchangeable cation population. Soils respond quickly to changes in conditions such as water content. As a result, the optimal frequency and distribution of soil measurements vary with the property being measured. Soil mineralogy, particle size distribution and soil depth are static soil quality indicators. Although changes occur continuously, they are slow under natural conditions. Organic matter content may be a dynamic variable, but the chemical properties of organic matter may change only over periods on the order of 100 to 1,500 years depending on texture. Soil properties that change quickly present a problem because many measurements are needed to know the average value and to determine if changes in the average indicate improvement or degradation of soil quality. Conversely, properties that change very slowly are insensitive measures of short-term changes in soil quality. Papendick et al. (1995) argue that the MDS required for soil quality analysis includes a mix of "dynamic" and relatively "static" properties. A soil quality assessment must specify area. One could use the pedon (the three-dimensional soil individual) as the unit of measure, or a soil map unit, a landscape, a field or an entire watershed. The choice will depend to some degree on what property is of interest and the spatial variability of the property. Karlen et al. (1997) propose that soil quality can be evaluated at scales ranging from points to regional, national and international. They suggest that the more detailed scales provide an opportunity to "understand" soil quality while larger scale approaches provide interdisciplinary monitoring of soil quality and changes in soil quality. Pennock et al. (1994) discuss scaling up data from discrete sampling points to landscape and regional scales. Soil physical characteristics [Aeration (A), Aggregate stability (AS), Bulk density (BD), Clay mineralogy (CM), Color (C), Consistence (dry (CD), moist (CM), wet (CW)), Depth to root limiting layer (DRLL), Hydraulic conductivity (HC), Oxygen diffusion rate (ODR), Particle size distribution (PSD), Penetration resistence (PR), Pore connectivity (PC), Pore size distribution (PSD), Soil strength (SS), Soil tilth (ST), Structure type (STY), Temperature (T), Total porosity (TP), Water-holding capacity (WHC)] are a necessary part of soil quality assessment because they often cannot be easily improved (Wagenet and Hutson, 1997). Larson and Pierce (1991) summarize the physical indicators of soil quality as those properties that influence crop production by determining: 1. whether a soil can accommodate unobstructed root growth and provide pore space of sufficient size and continuity for root penetration and expansion, 2. the extent to which the soil matrix will resist deformation, and 3. the capacity of soil for water supply and aeration. Factors such as effective rooting depth, porosity or pore size distribution, bulk density, hydraulic conductivity, soil strength and particle size distribution capture these soil functions (Malcolm, 2000; Várallyay, 2005). Reganold and Palmer (1995) use texture, color, dry and moist consistence, structure type, a structure index, bulk density of the 0-5 cm zone, penetration resistance of 0 to 20 and 20 to 40 cm zones and topsoil thickness as physical determinants of soil quality. Letey (1994) suggests that structure, texture, bulk density, and profile characteristics affect management practices in agriculture but are not directly related to plant productivity. He proposes that water potential, oxygen diffusion rate, temperature, and mechanical resistance directly affect plant growth, and thus are the best indicators of the physical quality of a soil for production. Soil tilth, a poorly defined term that describes the physical condition of soil, also may be an indicator of a soil's ability to support crops. Farmers may assess soil tilth by kicking a soil clod. More formal measurements to describe soil ti]th include bulk density, porosity, structure, roughness and aggregate characteristics (Karlen et al., 1992). Many of the processes that contribute to soil structure, aggregate stability, bulk density and porosity are not well understood, making soil tilth a difficult parameter to quantify. Soil depth is an easily measured and independent property that provides direct information about a soil's ability to support plants. Effective soil depth is the depth available for roots to explore for water and nutrients. Layers that restrict root growth or water movement include hard rock, naturally dense soil layers such as fragipans, petrocalcic and, petroferric horizons, duripans, and human-induced layers of high bulk density such as plow pans and traffic pans. Effective soil depth is a problem for agricultural use of over 50% of soils in Africa (Eswaran et al., 1997). Soil depth requirements vary with crop or species. Many vegetable crops, for example, are notably shallow rooted while grain crops and some legumes like alfalfa are deep rooted. Variation will be even greater in unmanaged, natural systems. Wheat yield in Colorado was shown to decrease from 2,700 to 1,150 kg ha' over a 60-yr period of cultivation primarily due to decrease in soil depth (Bowman et al., 1990). Assessment of soil quality based on soil chemistry, whether the property is a contaminant or part of a healthy system, requires a sampling protocol, a method of chemical analysis, an understanding of how its chemistry affects biological systems and interacts with mineral forms, methods for location of possible contamination, and standards for soil characterization (Várallyay, 2005; Németh, 1996; Malcolm, 2000). Some soil chemical properties suggested as soil quality indicators are: Base saturation percentage (BSP), Cation exchange capacity (CEC), Contaminant availability (CA), Contaminant concentration (CC), Contaminant mobility (CM), Contaminant presence (CP), Electrical conductivity (EC), ESP, Nutrient cycling rates (NCR), Ph, Plant nutrient availability (PNA), Plant nutrient content (PNC) and SAR. Nutrient availability depends on soil physical and chemical processes, such as weathering and buffering, and properties such as organic matter content, CEC and pH (Kádár, 1992; Várallyay, 1992, 1994, 2005; Németh, 1996; Malcolm, 2000; Márton, 2005; Márton et al. 2007). At low and high pH, for example, some nutrients become unavailable to plants and some toxic elements become more available. Larson and Pierce (1991) chose those chemical properties that either inhibit root growth or that affect nutrient supply due to the quantity present or the availability. Reganold and Palmer (1995) used chemical parameters related to nutrient availability as measures of soil quality, including CEC, total N and P, pH and extractable P, S, Ca, Mg and K. Karlen et al. (1992) suggest that total and available plant nutrients, and nutrient cycling rates, should be included in soil quality assessments. Soil properties may be severely compromised by intended or unintended human additions of chemical compounds and soil productivity reduced if unwanted chemicals exceed safe thresholds. Data are required to determine whether or not a site is significantly polluted and if it requires clean-up (Sims et al., 1997). International standard methods have been created to maintain the quality of measurements (Hortensius and Welling, 1996). A difficult determination is the level of each chemical that is considered an ecological risk. Beck et al. (1995) provide a list of levels for organic chemicals adopted by The Netherlands and Canada. EPA uses similar lists for compounds considered hazardous (e.g., 40 CFR). Sims et al. (1997) argue that clean and unclean are two extremes of a continuum and that it is more appropriate to define the physical, chemical and biological state of the soil as acceptable or unacceptable. In The Netherlands, soil quality reference values have been created for heavy metals and organic chemicals based on a linear relationship with soil clay and organic matter content. The Dutch Ministry of Housing, Physical Planning and Environment has used the maximum of a range of reference values for a given substance as a provisional reference value for good soil quality (Howard, 1993). The focus of many soil quality definitions is soil biology [Organic carbon (OC), Microbial biomass (MB), C and N, Total bacterial biomass (TBB), Total fungal biomass (TFB), Potentially mineralizable N (PMN), Soil respiration (SR), Enzymes (Dehydrogenase, Phosphatase, Arlysulfatase), Biomass C/total organic carbon, Respiration/biomass, Microbial community fingerprinting (MCF), Substrate utilization (SU), Fatty acid analysis (FAA), Nucleic acid analysis (NAA)]. Soil supports a diverse population of organisms, ranging in size from viruses to large mammals, that usually interacts positively with plants and other system components (Paul and Clark, 1996). However, some soil organisms such as nematodes, bacterial and fungal pathogens reduce plant productivity. Many proposed soil quality definitions focus on the presence of beneficial rather than absence of detrimental organisms, although both are critically important. Various measures of microbial community viability have been suggested as measures or indices of soil quality. Community level studies consider species diversity and frequency of occurrence of species. Visser and Parkinson (1992) found that diverse soil microbiological criteria may be used to indicate deteriorating or improving soil quality. They suggested testing the biological criteria for soil quality at three levels: population, community and ecosystem. Microorganisms and microbial communities are dynamic and diverse, making them sensitive to changes in soil conditions (Kennedy and Papendick, 1995). Their populations include fungi, bacteria including actinomycetes, protozoa, and algae. Soil microorganisms form crucial symbiotic relationships with plants, including mycorrhizal infection for P and N acquisition and bacterial infection for fixation of atmospheric N. Authors emphasizing use of biological factors as indicators of soil quality often equate soil quality with relatively dynamic properties such as microbial biomass, microbial respiration, organic matter mineralization and denitrification, and organic matter content (Yakovchenko et al., 1996; Franzluebbers and Arshad, 1997), or soil microbial C, phospholipid analyses and soil enzymes (Gregorich et al., 1997), or total organic C and N (Franco-Vizcaino, 1997). Visser and Parkinson (1992) question the suitability of enzyme assays for microbial activity and soil quality assessments. Waksman (1927), who studied measurements of soil microorganisms that could indicate soil fertility, found that physical and chemical factors as well as soil biology were needed to predict soil fertility. Meso- and macrofauna populations have also been considered as part of soil quality definitions (Berry, 1994). One could choose to use presence or absence of a particular species or population of a particular species as a measure of soil quality. Stork and Eggleton (1992) discuss species richness as a powerful indicator of invertebrate community and soil quality, although determining the number of species is a problem. They suggest that keystone species, taxonomic diversity at the group level, and species richness of several dominant groups of invertebrates can be used as part of a soil quality definition. Measuring soil fauna populations involves decisions about which organisms to measure and how to measure them. An example is the earthworm population, the size of which is frequently mentioned as an important measure of soil quality. Measurement choices include numbers of organisms per volume or weight of soil, number of species, or a combination of numbers of organisms and species. Reganold and Palmer (1995) use total earthworms per square meter, total earthworm weight (g m-') and average individual earthworm weight as biological indicators of soil quality. Measurement of one or more components of the N cycle including ammonification, nitrification and nitrogen fixation, may be used to assess soil fertility and soil quality (Visser and Parkinson, 1992). Presumably, high rates of N turnover may infer a dynamic and healthy soil biological community. In contrast, low soil quality or poor soil health may be inferred from lack of N turnover. The interpretation of N turnover rates is highly dependent on the kinds of substrates added to soils and climate variables such as soil temperature and moisture. One needs to be careful when comparing N turnover rates within soils and among different soils to be sure that the cause of differences is a soil quality parameter and not natural variability. Presence of pesticide residues, for example, may reduce N turnover rate. In such an instance, both the presence of the pesticide and the N turnover rate would be needed to determine that the soil quality had been impaired. Production incorporates use of and need for functioning soil resources in agriculture, and environmental buffering incorporates the direct and indirect effects of human use on ecosystem function and human health (Kádár, 1992; Várallyay, 1992, 1994, 2005; Németh, 1996; Malcolm, 2000; Márton, 2005; Márton et al. 2007). Worldwide agriculture is the most extensive human land use, and soil characteristics are a critical determinant of agricultural productivity. Agriculture includes irrigated and rainfed cultivated cropland, permanent crops such as orchards and vineyards, irrigated pasture, range, and forestry. Each cropping system has distinct soil and soil management conditions for optimal production. It has been suggested that soil productivity is the net resultant of soil degradation processes and soil conservation practices (Parr et al., 1990). An appropriate definition of soil quality and the criteria necessary to evaluate and monitor soil quality is a step toward "the development of systematic criteria of sustainability". Issues to be considered when discussing soil quality for agriculture include: 1. How are productivity and sustainability related? 2. Is the cropping system in question cultivated or non-cultivated? 3. Is the cropping system in question an irrigated or dryland system? Sustainability of agricultural systems is critical to human welfare and is an a subject of research and debate (Letey, 1994). High productivity and sustainability must be converging goals if the growing human population is to be fed without destroying the resources necessary to produce food. Sustainability implies that a system is at a desirable steady state. Thermodynamically, soil is an open system through which matter and energy flow and a steady state is characterized by a minimum production of entropy (Andiscott, 1995). Ellert et al. (1997) review related literature on ways of assessing soil function on an ecosystem scale, commenting that the complexity and organization of living systems, which seem to defy the second law of thermodynamics (increasing disorder/entropy), may provide a means to broadly assess ecosystem function. The purpose of agriculture is to provide products for human sustenance and by definition is not sustainable unless the nutrients removed in the products are returned to the soil. Many of the arguments about the sustainability of agricultural systems relate to the form in which nutrients are most sustainably returned. No agricultural system will be sustainable in the long run without management that considers nutrient cycling and energy budgets. The more intense the agricultural system, the more energy and resources must be expended to maintain the system. The relative quality of a soil for agriculture can depend on the resources available to farmers. In the United States, resources may be readily available for management of dynamic soil properties such as nutrient or water status. In other countries, farmers may be resource poor, and agricultural systems are generally low input, meaning that large-scale irrigation is absent, use of fertilizers, pesticides, and herbicides is minimal, and high energy, mechanized equipment is not available (Eswaran et a1.,1997). This means, for example, that soil quality for agriculture will be more dependent on climate than if the same soils were part of a highly managed, irrigated system. Similarly, sustainability is more dependent on maintenance of dynamic soil properties because resources may not exist to remedy losses (Várallyay, 2005; Malcolm, 2000; Márton et al. 2007). It is difficult to overstate the importance of irrigation to food production. One-third of the total global harvest of food comes from the 17% (250 million ha) of the world's cropland that is irrigated (Hoffman et al., 1990); three-quarters of which are in developing countries (Tribe, 1994). India, China, the former Soviet Union, the United States and Pakistan have the greatest area of irrigated land. Should soil quality criteria be the same for irrigated and dryland agriculture? Sojka (1996) suggests that the arid and semi-arid soils that support most irrigated agriculture have thin erodible surfaces, characteristics that would classify such soils as having poor quality. Yet under irrigation, they feed much of the world. Without irrigation, for example, in many African soils, moisture stress becomes a significant factor limiting production, and the water-holding capacity of a soil becomes crucial (Eswaran et al., 1997). This suggests that a standard set of criteria based on potential productivity is not a sufficient definition of soil quality. Soils that are not cultivated are a much larger component of agriculture, broadly defined, than those that are cultivated. About 65% of the land in the United States is forest (284 million ha) or range land (312 million ha), with only about 284 million hacultivated (NRC,1994). Herrick and Whitford (1995) suggest that range land soils, which often serve multiple uses, present unique challenges and opportunities for assessing soil quality because spatial and temporal variability are higher than in cropped systems. On range lands and forest lands, food, fiber, timber production, biomass for fuel, wildlife, biodiversity, recreation, and water supply are all potential uses that may have diverse criteria for quality soils. Herrick and Whitford (1995) give the example of a thick O horizon that may be an indicator of good timber production but has no predictive value of soil quality for the rancher. The National Research Council (NRC, 1994) recommends that range land health be determined using three criteria: degree of soil stability and watershed function, integrity of nutrient cycles and energy flows, and presence of functioning recovery mechanisms. Soil erosion by wind and water and infiltration or capture of precipitation were selected as processes that could be used as indicators of soil stability and watershed function. Specific indicators or properties need to be related to these two broad processes. The amount of nutrients available, the speed with which nutrients cycle, and measures of the integrity of energy flow through the system were considered fundamental components of range land health. Finally, the capacity of range land ecosystems to react to change depends on recovery mechanisms that result in capture and cycling of nutrients, capture of energy, conservation of nutrients, energy and water, and resilience to change. Specific indicators include status of vegetation, age class and distribution (Kádár, 1992; Várallyay, 1992, 1994, 2005; Németh, 1996; Malcolm, 2000; Márton et al. 2007). The evaluation of land quality for forestry is a well-known practice. Indices range from quantitative through semi-quantitative to qualitative. Quantitative evaluations, such as site index, use regression equations to predict tree height at a predetermined tree age based on soil and climate data. Qualitative evaluations assign land to classes based on soil and climate properties. In soil science, the term "buffer" refers collectively to processes that constrain shifts in the dissolved concentration of any ion when it is added to or removed from the soil system (Singer and Munns, 1996). Soils "buffer" nutrients as well as contaminants and other solutes, via sorption to or incorporation into clay and organic materials. The extent to which a soil immobilizes or chemically alters substances that are toxic, thus effectively detoxifying them, reflects "quality" in the sense that humans or other biological components of the system are protected from harm. This is the basis for the European concept of soil quality (Moen, 1988; Siegrist, 1989; Denneman and Robberse, 1990). Lack of soil function in this category is reflected as direct toxicity or as contamination of air or water. Identifying substances that qualify as "contaminants" can be challenging because some, such as nitrates and phosphates, are important plant nutrients as well as potential water pollutants. An example is agricultural runoff containing N03 or soluble P (Yli-Halla et al., 1995). This chapter does not attempt a comprehensive review of research in this area, which is covered in an earlier chapter, but instead presents a few sample articles pertinent to this aspect of soil quality. Holden and Firestone (1997) define soil quality in this context as "the degree to which the physical, chemical, and biological characteristics of the soil serve to attenuate environmental pollution." Howard (1993) defines the ecological risk of a chemical in the environment as "the probability that a random species in a large community is exposed to a concentration of the chemical greater than its no-effect level." The extent to which a soil is capable of reducing the probability of exposure is a measure of its quality. A well-studied example of a common soil contaminant is Pb (McBride et al., 1997). Although legislated limits may be on a concentration basis in soil (e.g., 500 ftg kg-'), risk assessment techniques have attempted to account for the chemical form of Pb present, as well as the observed relative relationship between the amount of Pb present in soil and blood levels in local residents (Bowers and Gauthier, 1994). Critics have questioned analytical techniques used to determine bioavailable levels of Pb in soil, as well as the degree to which toxicity data account for its chemical fate and ecologically damaging properties (Cook and Hendershot, 1996). Natural variability of soils and variation within a soil series make average values or average background values inadequate for soil quality assessments. In addition, bioaccumulation and toxicity need to be considered when establishing levels of toxicants that may not be exceeded in a "high quality" soil for a given use (Traas et al. 1996). Another example is the effect of heavy metals such as Cr(VI) on soil biological properties. Based on a study of three New Zealand soils of contrasting texture, organic matter content, and CEC, Speir et al. (1995) propose an "ecological dose value" that represents the inhibitory effects of a heavy metal (in this case, Cr(VI)) on the kinetics of soil biological properties, and serves as a generic index for determination of permissible concentration levels for heavy metals in soils. A single soil characteristic is of limited use in evaluating differences in soil quality (Reganold and Palmer, 1995). Using more than one quantitative variable requires some system for combining the measurements into a useful index (Halvorson et al., 1996). The region, crop, or general soil use for which an index was created will likely limit its effectiveness outside the scope of its intended application. Even an index designed only to rate productivity is not likely to be useful for all crops and soils, leading Gersmehl and Brown (1990) to advocate regionally targeted systems. Rice is a good example of a crop requiring significantly different soil properties than other crops. It is a food staple for a large proportion of the world population. Approximately 146 million ha were in rice production in 1989 (FAO, 1989) mainly (90%) in Asia. High quality soils for paddy rice may be poor quality for most other irrigated and dryland crops because they may be saline or sodic, and high in clay with slow infiltration and permeability. These physical and chemical properties often constrain production of other crops. Although they are not reviewed here, various land suitability classifications specifically for rice have been developed since the turn of the century (Dent, 1978). Examples of several soil quality indexing systems are presented in the following sections. To some extent, recent attempts to enumerate the factors of soil quality resemble Jenny's (1941) introduction of the interrelated factors of soil formation. An index is categorized here as nonquantitative if it does not combine evaluated parameters into a numerical index that rates soils along a continuous scale. Examples are the USDA Land Capability Classification and the US Bureau of Reclamation (USBR) Irrigation Suitability. The purpose of the Land Capability Classification (LCC) was to place arable soils into groups based on their ability to sustain common cultivated crops that do not require specialized site conditioning or treatment (Klingebiel and Montgomery, 1973). Nonarable soils, unsuitable for long-term, sustained cultivation, are grouped according to their ability to support permanent vegetation, and according to the risk of soil damage if mismanaged. The LCC combines three rating values at different levels of abstraction: capability class, subclass, and unit. At the most general level, soils are placed in eight classes according to whether they (a) are capable of producing adapted plants under good management (classes I to N), (b) are capable of producing specialized crops under highly intensive management involving "elaborate practices for soil and water conservation" (classes V to VII), or (c) do not return on-site benefits as a result of management inputs for crops, grasses or trees without major reclamation (Klingebiel and Montgomery, 1973). The four possible limitations/hazards under the subclass rating are erosion hazard, wetness, rooting zone limitations and climate. The capability unit groups soils that have about the same responses to systems of management and have longtime estimated yields that do not vary by more than 25% under comparable management. The issue of critical limits is a difficult one in soils because of the range of potential uses and the interactions among variables (Arshad and Ccen, 1992). Several studies have shown that lands of higher LCC have higher productivity than lands of lower LCC (Patterson and Mackintosh, 1976; van Vliet et al., 1979; Reganold and Singer, 1984). In a study of 744 alfalfa, corn, cotton, sugar beet and wheat growing fields in the San Joaquin Valley of California, those with LCC ratings between 1 and 3 had significantly lower input/output ratios than fields with ratings between 3.01 and 6 (Reganold and Singer, 1984). This suggests that use of the LCC system provides an economically meaningful assessment of soil quality for agriculture. This was a frequently used system of land evaluation for irrigation in the Western US during the period of rapid expansion of water delivery systems (McRae and Burnham, 1981). It combines social and economic evaluations of the land with soil and other ecological variables to determine if the land has the productive capacity, once irrigated, to repay the investment necessary to bring water to an area. It recognizes the unique importance of irrigation to agriculture and the special qualities of soils that make them irrigable. Quantitative systems result in a numerical index, typically with the highest number being assigned to the best quality soils. Systems may be additive, multiplicative or more complex functions. They have two important advantages over nonquantitative systems: 1. they are easier to use with GIS and other automated data retrieval and display systems, and 2. they typically provide a continuous scale of assessment. No single national system is presently in use but several state or regional systems exist. Although he considered the productivity of the land to be dependent on 32 soil, climate and vegetative properties [Surface conditions: Physiographic position, Slope, Microrelief, Erosion deposition, External drainage, runoff. Soil physical conditions: Soil color, Soil depth, Soil density and porosity, Soil permeability, Soil texture, Stoniness, Soil structure, Soil workability-consistence, Internal drainage, Water-holding capacity, Plant-available water. Soil chemical conditions: Organic matter, Nitrogen, Reaction, Calcium carbonate, bases, Exchange capacity, Salts: Cl, SO Na, Toxicities, e.g., B, Available P, Available K, Minor elements, e.g., Zn, Fe, Fertility. Mineralogical conditions: Mineralogy. Climate: Precipitation Temperature Growing season Winds. Vegetativé cover: Natural vegetation], only nine properties were used in the SIR, because incorporating a greater number of factors made the system unwieldy. The nine factors are soil morphology (A), surface texture (B), slope (C), and six variables (X.) that rate drainage class, sodicity, acidity, erosion, microrelief and fertility; rated from 1% to 100%. These are converted to their decimal value and multiplied together (Storie, 1964). Values for each factor were derived from Storie's experience mapping and evaluating soils in California, and in soil productivity studies in cooperation with the California Agricultural Experiment Station cost-efficiency projects relating to orchard crops, grapes and cotton. In describing the SIR (SIR= [AxBxCxIIXi]x100), Storie (1932, 1964) explicitly mentioned "soil quality". Soils that were deep, had no restricting subsoil horizons, and held water well had the greatest potential for the widest range of crops. The usefulness of the SIR as a soil quality index would be greatest if there was a statistically significant relationship between SIR values and an economic indicator of land value. Reganold and Singer (1984) found that area-weighted average SIR values between 60 and 100 for 744 fields in the San Joaquin Valley of California had lower but statistically insignificant input/output ratios than fields with indices < 60. The lack of statistical significance does not mean that better quality lands could not be farmed at economically lower cost or at higher cost and higher output than the lower quality lands. We productivity index model (PI) was developed to evaluate soil productivity in the top 100 cm, especially with reference to potential productivity loss due to soil erosion (Neill, 1979; Kiniry et al., 1983). The PI model rates soils on the sufficiency for root growth based on potential available water storage capacity, bulk density, aeration, pH, and electrical conductivity. A value from zero to one is assigned to each property describing the importance of that parameter for root development. The product of these five index values is used to describe the fractional sufficiency of any soil layer for root development. Pierce et al. (1983) modified the PI to include the assumption that nutrients were not limiting and that climate, management and plant differences are constant. A number of authors found that it is useful to various degrees (Gantzer and McCarty, 1987; Lindstrom et al., 1992). Parr et al. (1992) suggest that a SQI could take the form of Equation: SQI = f (SP, P, E, H, ER, BD, FQ, MI) where SQI is a function of soil properties (SP), potential productivity (P), environmental factors (E), human and animal health (H), erodibility (ER), biological diversity (BD), food quality and safety (FQ) and management inputs (MI). Determination of the specific measurable indicators of each variable and the interactions among these diverse variables is a daunting task. Moreover, the mathematical method of combining these factors, as well as the resulting value that would indicate a high quality soil, is not specified. The inclusion of variables BD, FQ and MI make this a land quality index as suggested by FAO (1997). Larson and Pierce (1991) defined soil quality (Q) as the state of existence of soil relative to a standard or in terms of a degree of excellence. They argue that defining Q in terms of productivity is too limiting and does not serve us well. Rather, Q is defined as the sum of individual soil qualities q. and expressed as Equation: Q=f(qi ...qn). These authors do not identify the best subset of properties or their functional and quantitative relationship, but do suggest that a MDS should be selected from those soil characteristics in which changes are measurable and relatively rapid (i.e., "dynamic" properties), arguing that it is more important to know about changes in soil quality (dQ) than the magnitude of Q (Larson and Pierce, 1991). Changes in soil quality are a function of changes in soil characteristics (q) over time (t): dQ = f[(qi.t - qit0 )... (qn.t-qnt0)]. If dQ/dt is ≥0, the soil or ecosystem is improving relative to the standard at time to. If dQ/dt <0, soil degradation is occurring. Time zero can be selected to meet management needs or goals. If there is a drastic change in management, time zero can be defined as prior to the change. If a longer time period of comparison is considered more appropriate, properties of an uncultivated or pristine soil could be used. The MDS recommended by Larson and Pierce (1991) includes N mineralization potential or P buffering capacity, total organic C, labile organic C, texture, plant-available water capacity, structure (bulk density is recommended as a surrogate variable), strength, maximum rooting depth, pH and EC. In instances when data are unavailable, pedotransfer functions (Bouma, 1989) can be used to estimate values of soil characteristics. These estimates can then be used as part of the minimum dataset to estimate soil quality or changes in soil quality brought about by management. Although this is a quantitative system, some qualitative judgments are needed to make decisions about changes in soil quality. In particular, interpretation of the meaning of magnitude of changes in a characteristic or the number of characteristics to change from time zero to the time of the measurement is qualitative. The authors do not address how large a change in pH, soil depth, bulk density or organic C represents serious soil degradation, or the values that define soil as high or low quality. Karlen et al. (1994) developed QI based on a 10-year crop residue management study. QI is based on four soil functions: (1) accommodating water entry, (2) retaining and supplying water to plants, (3) resisting degradation, and (4) supporting plant growth. Numerous properties were measured and values normalized based on standard scoring functions. One function is based on the concept that more of a property is better, one that less is better and the third that an optimum is better. Lower threshold values receive a score of zero, upper threshold values receive a score of one, and baseline values receive a score of one-half. Priorities are then assigned to each value. For example, aggregate stability was given the highest weight among factors important in water entry. After normalizing, each value is then multiplied by its weighting factor (wt) and products are summed Equation: QI=qwe (wt) + qwt (wt)+qrd (wt) + qspg (wt). Subscripts refer to the four main functions described earlier. It should also be noted that resisting degradation (rd) and sustaining plant growth (spg) are assigned secondary and tertiary levels of properties that themselves are normalized and weighted before a final value is calculated and incorporated into Equation. The resulting index resulted in values between zero and one. Of the three systems in the study, the one with the highest rate of organic matter return to the soil had the highest index value, and the soil with the lowest had the lowest value. The authors suggest that this demonstrates the usefulness of the index for monitoring the status and change in status of a soil as a function of management. They also suggest that the index and the soil characteristics that go into the index may change as the index is refined (Karlen et al. 1994). Snakin et al. (1996) developed an index of soil degradation that assigns three separate values from one to five reflecting the degree to which a soil's physical, chemical, and biological properties are degraded, as well as the rate of degradation. The Canadian soil capability classification system is similar to the older US systems and is quantitative. In a study in southwestern Ontario, Patterson and Mackintosh (1976) found that high gross returns per ha were three times as likely if the productivity index of land, based on the soil capability classification, was between 90 and 100 than if it fell between 80 and 89. Smith et al. (1993) and Halvorson et al. (1996) propose a multiple-variable indicator transform procedure to combine values or ranges of values that represent the best estimate of soil quality. Their system converts measured data values into a single value according to specified criteria. They do not attempt to define soil quality or specify what soil characteristics are to be used. They combine this procedure with kriging to develop maps that indicate the probabilities of meeting a soil quality criterion on a landscape level. Critical threshold values must be known, assumed, or determined in order to separate different soil qualities. Numerous additive productivity rating systems have been developed for specific states, as reviewed by Huddleston (1984). In these systems, soil properties are assigned numerical values according to their expected impact on plant growth. The index is usually calculated as the sum of the values assigned to each property with 100 the maximum value. Huddleston (1984) notes advantages and disadvantages to such a system which are similar to those for many of the soil quality indices previously discussed. Additive systems become complex as the number of factors, cropping systems, and soil and climatic conditions increases. A unique problem of subtractive systems (one in which 100 is the starting point and values are deducted for problem conditions) is that negative values result when multiple factors are less than satisfactory. Soil quality is a concept being developed to characterize the usefulness and health of soils, because soils are fundamental to the well-being and productivity of agricultural and natural ecosystems. It is a compound characteristic that cannot be directly measured. Many definitions of soil quality can be found in the literature and no set of soil characteristics has been universally adopted to quantify definitions. Soil quality is often equated with agricultural productivity and sustainability. An approach toward developing soil quality definitions is one that assesses soil quality in the context of a soil's potential to perform given functions in a system; e.g., maintains productivity, partitions and regulates water and solute flow through an ecosystem, serves as an environmental buffer, and cycles nutrients, water, and energy through the biosphere. Air and water quality standards are usually based on maximum allowable concentrations of materials hazardous to human health. A definition of soil quality based on this concept would encompass only a fraction of the important roles soils play in agriculture and the environment but could be essential to soil remediation. To proceed from a definition to a measure of soil quality, a minimum dataset of soil characteristics that represent soil quality must be selected and quantified. Many soil physical, chemical and biological properties have been suggested to separate soils of different quality. These include desirable and undesirable properties. Desirable soil characteristics may either be the presence of a property that benefits crop productivity and environmental buffering and/or other important soil functions, or the absence of a property that is detrimental to these functions. In particular, absence of contaminants is an important soil quality characteristic. In selecting characteristics, it is necessary to recognize that some soil properties are static, in the sense that they change slowly over time and others are dynamic. In addition, spatial and temporal variability of soil properties must be considered when selecting the properties used to assess soil quality. A single soil property is of limited use in evaluating soil quality. Qualitative and quantitative soil quality indices have been suggested that combine quantitative values of soil properties. Quantitative systems may be additive, multiplicative or more complex functions. Regardless of the definition or suite of soil variables chosen to define and quantify soil quality, it is critical to human welfare that soils be managed to provide for human health and well-being while minimizing soil and environmental degradation. References Anderson, D.W., E.G. Gregorich. 1984. Effect of soil erosion on soil quality and productivity. p. 105-113. In Soil erosion and degradation. Proc. 2nd Ann. Western Prov. Conf. Rational. Water Soil Res. Manag. Sask., Saskatoon, Canada. Andiscott, T.M. 1995. Entropy and sustainability. Europ. J. Soil Sci. 46:161-168. Arnold, R.W., I. Zaboles., V.C. Targulian (ed.). 1990. Global soil change. Report of an IIASA-ISSS-UNEP task force on the role of soil in global change. International Institute for Applied Systems Analysis, Laxanberg, Austria. Arshad, M-A., G.M. Coen. 1992. Characterization of soil quality: Physical and chemical criteria. Am. J. Altern. Agr. 725-3 I . Beck, A.J., S.C. Wilson., R.E. Alcock., K.C. Jones. 1995. Kinetic constraints on the loss of organic chemicals from contaminated soils: Implications for soil-quality limits. Critical Rev. Environ. Sci. Technol. 25:1-43. Beke, G.J., H.H. Janzen., T. Entz. 1994. Salinity and nutrient distribution in soil profiles of long-term crop rota-tions. Can. J. Soil Sci. 74:229-234. Berry, E.C. 1994. Earthworms and other fauna in the soil, p. 61-90. In J.L. Hatfield and B A. Stewart (ed.) Soil biology: effects on soil quality. Lewis Publishers, Boca Raton, FL. Biederbeck, V.O., C.A. Campbell., H.U. Krainetz., D. Curtain., O.T Bouman. 1996. Soil microbial and biochemical properties after ten years of fertilization with urea and anhydrous ammonia. Can. J. Soil Sci. 76:7-14. Boehn, M.M., D.W. Anderson. 1997. A landscape-scale study of soil quality in three prairie farming systems. Soil Sci. Soc. Am. J. 61:1147-1159. Bouma, J. 1989. Land qualities in space and time. p. 3-13. In J. Bouma and A.K. Bregt (ed.) Land qualities in space and time. Pudoc, Wageningen, Netherlands. Bouma, J., A.K. Bregt (ed.). 1989. Land qualities in space and time. Pudoc, Wageningen, Netherlands. Bowers, T.S., T.D. Gauhier. 1994. Use of the output of a lead risk assessment model to establish soil lead cleanup levels. Environ. Geochem. Health 16:191-196. Bowman, R.A., J.D. Reeder., G.E. Schuman. 1990. Evaluation of selected soil physical, chemical and biological parameters as indicators of soil productivity. Proc. Int. Conf. on Soil Quality in Semi-arid Ag. 2:64-70. Univ. of Saskatchewan, Saskatoon, Canada. Budd, W.W. 1992. What capacity the land? J. Soil Water Conserv. 47:28-31. Carter, MR., E.G. Gregorich., D.W Anderson., J.W. Doran., H.H. Janzen., F.J. Pierce. 1997. Concepts of soil quality and their significance: /n E.G. Gregorich and M. Carter (ed.) Soil quality for crop production and ecosys-tem health. Elsevier Science Publishers, Amsterdam, Netherlands. Cook, N., W.H. Hendershot. 1996. The problem of establishing ecologically based soil quality criteria: The case of lead. Can J. Soil Sci. 76:335-342. Cox, C. 1995. Soil quality: Goals for national policy. J. Soil Water Conserv. 50:223. Denneman, C.A.J., J.G. Robberse. 1990. Ecotoxicological risk assessment as a base for development of soil quality criteria. p. 157-164. In F Arendt, M. Hinsenveld and W.J. van den Brink (ed.) Contaminated soil '90. Proc. Intl. KfK/I'NO Conf. on Contaminated Soil, Karlsruhe, Germany, Kluwer Academic Publishers, Dordrecht, Neth-erlands. Dent, F.J. 1978. Land suitability classification. p. 273-293. In Soils and rice. International Ri

Soil fertility shapes belowground food webs across a regional climate gradient.

PubMed

Laliberté, Etienne; Kardol, Paul; Didham, Raphael K; Teste, François P; Turner, Benjamin L; Wardle, David A

2017-10-01

Changes in soil fertility during pedogenesis affect the quantity and quality of resources entering the belowground subsystem. Climate governs pedogenesis, yet how climate modulates responses of soil food webs to soil ageing remains unexplored because of the paucity of appropriate model systems. We characterised soil food webs along each of four retrogressive soil chronosequences situated across a strong regional climate gradient to show that belowground communities are predominantly shaped by changes in fertility rather than climate. Basal consumers showed hump-shaped responses to soil ageing, which were propagated to higher-order consumers. There was a shift in dominance from bacterial to fungal energy channels with increasing soil age, while the root energy channel was most important in intermediate-aged soils. Our study highlights the overarching importance of soil fertility in regulating soil food webs, and indicates that belowground food webs will respond more strongly to shifts in soil resources than climate change. © 2017 John Wiley & Sons Ltd/CNRS.

Assessment of groundwater and soil quality degradation using multivariate and geostatistical analyses, Dakhla Oasis, Egypt

NASA Astrophysics Data System (ADS)

Masoud, Alaa A.; El-Horiny, Mohamed M.; Atwia, Mohamed G.; Gemail, Khaled S.; Koike, Katsuaki

2018-06-01

Salinization of groundwater and soil resources has long been a serious environmental hazard in arid regions. This study was conducted to investigate and document the factors controlling such salinization and their inter-relationships in the Dakhla Oasis (Egypt). To accomplish this, 60 groundwater samples and 31 soil samples were collected in February 2014. Factor analysis (FA) and hierarchical cluster analysis (HCA) were integrated with geostatistical analyses to characterize the chemical properties of groundwater and soil and their spatial patterns, identify the factors controlling the pattern variability, and clarify the salinization mechanism. Groundwater quality standards revealed emergence of salinization (av. 885.8 mg/L) and extreme occurrences of Fe2+ (av. 17.22 mg/L) and Mn2+ (av. 2.38 mg/L). Soils were highly salt-affected (av. 15.2 dS m-1) and slightly alkaline (av. pH = 7.7). Evaporation and ion-exchange processes governed the evolution of two main water types: Na-Cl (52%) and Ca-Mg-Cl (47%), respectively. Salinization leads the chemical variability of both resources. Distinctive patterns of slight salinization marked the northern part and intense salinization marked the middle and southern parts. Congruence in the resources clusters confirmed common geology, soil types, and urban and agricultural practices. Minimizing the environmental and socioeconomic impacts of the resources salinization urges the need for better understanding of the hydrochemical characteristics and prediction of quality changes.

Wetland biogeochemistry and ecological risk assessment

NASA Astrophysics Data System (ADS)

Bai, Junhong; Huang, Laibin; Gao, Haifeng; Zhang, Guangliang

2017-02-01

Wetlands are an important ecotone between terrestrial and aquatic ecosystems and can provide great ecological service functions. Soils/sediments are one of the important components of wetland ecosystems, which support wetland plants and microorganisms and influence wetland productivity. Moreover, wetland soils/sediments serve as sources, sinks and transfers of carbon, nitrogen, phosphorus and chemical contaminants such as heavy metals. In natural wetland ecosystems, wetland soils/sediments play a great role in improving water quality as these chemical elements can be retained in wetland soils/sediments for a long time. Moreover, the biogeochemical processes of the abovementioned elements in wetland soils/sediments can drive wetland evolution and development, and their changes will considerably affect wetland ecosystem health. Therefore, a better understanding of wetland soil biogeochemistry will contribute to improving wetland ecological service functions.

Managing soil microbial communities in grain production systems through cropping practices

NASA Astrophysics Data System (ADS)

Gupta, Vadakattu

2013-04-01

Cropping practices can significantly influence the composition and activity of soil microbial communities with consequences to plant growth and production. Plant type can affect functional capacity of different groups of biota in the soil surrounding their roots, rhizosphere, influencing plant nutrition, beneficial symbioses, pests and diseases and overall plant health and crop production. The interaction between different players in the rhizosphere is due to the plethora of carbon and nutritional compounds, root-specific chemical signals and growth regulators that originate from the plant and are modulated by the physico-chemical properties of soils. A number of plant and environmental factors and management practices can influence the quantity and quality of rhizodeposition and in turn affect the composition of rhizosphere biota communities, microbe-fauna interactions and biological processes. Some of the examples of rhizosphere interactions that are currently considered important are: proliferation of plant and variety specific genera or groups of microbiota, induction of genes involved in symbiosis and virulence, promoter activity in biocontrol agents and genes correlated with root adhesion and border cell quality and quantity. The observation of variety-based differences in rhizodeposition and associated changes in rhizosphere microbial diversity and function suggests the possibility for the development of varieties with specific root-microbe interactions targeted for soil type and environment i.e. designer rhizospheres. Spatial location of microorganisms in the heterogeneous field soil matrix can have significant impacts on biological processes. Therefore, for rhizosphere research to be effective in variable seasonal climate and soil conditions, it must be evaluated in the field and within a farming systems context. With the current focus on security of food to feed the growing global populations through sustainable agricultural production systems there is a need to develop innovative cropping systems that are both economically and environmentally sustainable.

Phosphogypsum capping depth affects revegetation and hydrology in Western Canada.

PubMed

Jackson, Mallory E; Naeth, M Anne; Chanasyk, David S; Nichol, Connie K

2011-01-01

Phosphogypsum (PG), a byproduct of phosphate fertilizer manufacturing, is commonly stacked and capped with soil at decommissioning. Shallow (0, 8, 15, and 30 cm) and thick (46 and 91 cm) sandy loam caps on a PG stack near Fort Saskatchewan, Alberta, Canada, were studied in relation to vegetation establishment and hydrologic properties. Plant response was evaluated over two growing seasons for redtop ( L.), slender wheatgrass ( (Link) Malte ex H.F. Lewis), tufted hairgrass ( (L.) P. Beauv.), and sheep fescue ( L.) and for a mix of these grasses with alsike clover ( L.). Water content below the soil-PG interface was monitored with time-domain reflectometry probes, and leachate water quantity and quality at a depth of 30 cm was measured using lysimeters. Vegetation responded positively to all cap depths relative to bare PG, with few significant differences among cap depths. Slender wheatgrass performed best, and tufted hairgrass performed poorly. Soil caps <1 m required by regulation were sufficient for early revegetation. Soil water fluctuated more in shallow than in thick caps, and water content was generally between field capacity and wilting point regardless of cap depth. Water quality was not affected by cap depths ≤30 cm. Leachate volumes at 30 cm from distinct rainfall events were independent of precipitation amount and cap depth. The study period had lower precipitation than normal, yet soil caps were hospitable for plant growth in the first 2 yr of establishment. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Microbial community composition explains soil respiration responses to changing carbon inputs along an Andes-to-Amazon elevation gradient

PubMed Central

Whitaker, Jeanette; Ostle, Nicholas; Nottingham, Andrew T; Ccahuana, Adan; Salinas, Norma; Bardgett, Richard D; Meir, Patrick; McNamara, Niall P; Austin, Amy

2014-01-01

1. The Andes are predicted to warm by 3–5 °C this century with the potential to alter the processes regulating carbon (C) cycling in these tropical forest soils. This rapid warming is expected to stimulate soil microbial respiration and change plant species distributions, thereby affecting the quantity and quality of C inputs to the soil and influencing the quantity of soil-derived CO2 released to the atmosphere. 2. We studied tropical lowland, premontane and montane forest soils taken from along a 3200-m elevation gradient located in south-east Andean Peru. We determined how soil microbial communities and abiotic soil properties differed with elevation. We then examined how these differences in microbial composition and soil abiotic properties affected soil C-cycling processes, by amending soils with C substrates varying in complexity and measuring soil heterotrophic respiration (RH). 3. Our results show that there were consistent patterns of change in soil biotic and abiotic properties with elevation. Microbial biomass and the abundance of fungi relative to bacteria increased significantly with elevation, and these differences in microbial community composition were strongly correlated with greater soil C content and C:N (nitrogen) ratios. We also found that RH increased with added C substrate quality and quantity and was positively related to microbial biomass and fungal abundance. 4. Statistical modelling revealed that RH responses to changing C inputs were best predicted by soil pH and microbial community composition, with the abundance of fungi relative to bacteria, and abundance of gram-positive relative to gram-negative bacteria explaining much of the model variance. 5. Synthesis. Our results show that the relative abundance of microbial functional groups is an important determinant of RH responses to changing C inputs along an extensive tropical elevation gradient in Andean Peru. Although we do not make an experimental test of the effects of climate change on soil, these results challenge the assumption that different soil microbial communities will be ‘functionally equivalent’ as climate change progresses, and they emphasize the need for better ecological metrics of soil microbial communities to help predict C cycle responses to climate change in tropical biomes. PMID:25520527

Building a strategy for soil protection at local and regional scale--the case of agricultural wastes landspreading.

PubMed

Doula, M K; Sarris, A; Hliaoutakis, A; Kydonakis, A; Papadopoulos, N S; Argyriou, L

2016-03-01

Agricultural wastes (AW) are produced in huge quantities worldwide and may cause detrimental effects on environmental quality, affecting soil, water, and air quality. Given the growing soil degradation worldwide, the need for more food of good quality and therefore the intensified agriculture, it is important to develop recycling plans even for those types of treated AW (e.g., composts) that are not considered hazardous. Two strategic approaches for safe and sustainable landspreading of organic wastes are proposed, depending on wastes properties and hazard potential, i.e., an approach appropriate for traditionally used wastes (manures and composts) and another approach for wastes that are potentially hazardous or hazardous and should only be reused under specific restrictions. Both approaches foresee concrete steps, require close cooperation between farmers and local/regional authorities, and are appropriate to ensure environmental sustainability at AW recycling or disposal areas. Desktop and web application tools are also presented that are anticipated to assist authorities in implementing their monitoring strategies.

Phytoremediation of Metal-Contaminated Soils

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shtangeeva, I.; Laiho, J.V-P.; Kahelin, H.

2004-03-31

Recent concerns regarding environmental contamination have necessitated the development of appropriate technologies to assess the presence and mobility of metals in soil and estimate possible ways to decrease the level of soil metal contamination. Phytoremediation is an emerging technology that may be used to cleanup contaminated soils. Successful application of phytoremediation, however, depends upon various factors that must be carefully investigated and properly considered for specific site conditions. To efficiently affect the metal removal from contaminated soils we used the ability of plants to accumulate different metals and agricultural practices to improve soil quality and enhance plant biomass. Pot experimentsmore » were conducted to study metal transport through bulk soil to the rhizosphere and stimulate transfer of the metals to be more available for plants' form. The aim of the experimental study was also to find fertilizers that could enhance uptake of metals and their removal from contaminated soil.« less

Soil physical and hydrological properties as affected by long-term addition of various organic amendments

NASA Astrophysics Data System (ADS)

Eden, Marie; Völkel, Jörg; Mercier, Vincent; Labat, Christophe; Houot, Sabine

2014-05-01

The use of organic residues as soil amendments in agriculture not only reduces the amount of waste needing to be disposed of; it may also lead to improvements in soil properties, including physical and hydrological ones. The present study examines a long-term experiment called "Qualiagro", run jointly by INRA and Veolia Environment in Feucherolles, France (near Paris). It was initiated in 1998 on a loess-derived silt loam (787 g/kg silt, 152 g/kg clay) and includes ten treatments: four types of organic amendments and a control (CNT) each at two levels of mineral nitrogen (N) addition: minimal (Nmin) and optimal (Nopt). The amendments include three types of compost and farmyard manure (FYM), which were applied every other year at a rate of ca. 4 t carbon ha-1. The composts include municipal solid waste compost (MSW), co-compost of green wastes and sewage sludge (GWS), and biowaste compost (BIO). The plots are arranged in a randomized block design and have a size of 450 m²; each treatment is replicated four times (total of 40 plots). Ca. 15 years after the start of the experiment soil organic carbon (OC) had continuously increased in the amended plots, while it remained stable or decreased in the control plots. This compost- or manure-induced increase in OC plays a key role, affecting numerous dependant soil properties like bulk density, porosity and water retention. The water holding capacity (WHC) of a soil is of particular interest to farmers in terms of water supply for plants, but also indicates soil quality and functionality. Addition of OC may affect WHC in different ways: carbon-induced aggregation may increase larger-pore volume and hence WHC at the wet end while increased surface areas may lead to an increased retention of water at the dry end. Consequently it is difficult to predict (e.g. with pedotransfer functions) the impact on the amount of water available for plants (PAW), which was experimentally determined for the soils, along with the entire range of the water retention curve. The impact of organic amendments on water retained at field capacity (FC) and wilting point (WP) as well as the retention curve in general differed compared to CNT but also depends on the definition of FC (the associated matric potential). Overall, within the first 15 years of the experiment, the organic treatments affected and generally improved various soil properties relevant in terms of quality, functionality and productivity. Acknowledgment: This work was granted by ADEME within the Pro-Extern project.

Pesticide interactions with soils affected by olive oil mill wastewater

NASA Astrophysics Data System (ADS)

Keren, Yonatan; Bukhanovsky, Nadezhda; Borisover, Mikhail

2013-04-01

Soil pesticide sorption is well known to affect the fate of pesticides, their bioavailability and the potential to contaminate air and water. Soil - pesticide interactions may be strongly influenced by soil organic matter (SOM) and organic matter (OM)-rich soil amendments. One special OM source in soils is related to olive oil production residues that may include both solid and liquid wastes. In the Mediterranean area, the olive oil production is considered as an important field in the agricultural sector. Due to the significant rise in olive oil production, the amount of wastes is growing respectively. Olive oil mill waste water (OMWW) is the liquid byproduct in the so-called "three phase" technological process. Features of OMWW include the high content of fatty aliphatic components and polyphenols and their often-considered toxicity. One way of OMWW disposal is the land spreading, e.g., in olive orchards. The land application of OMWW (either controlled or not) is supposed to affect the multiple soil properties, including hydrophobicity and the potential of soils to interact with pesticides. Therefore, there is both basic and applied interest in elucidating the interactions between organic compounds and soils affected by OMWW. However, little is known about the impact of OMWW - soil interactions on sorption of organic compounds, and specifically, on sorption of agrochemicals. This paper reports an experimental study of sorption interactions of a series of organic compounds including widely used herbicides such as diuron and simazine, in a range of soils that were affected by OMWW (i) historically or (ii) in the controlled land disposal experiments. It is demonstrated that there is a distinct increase in apparent sorption of organic chemicals in soils affected by OMWW. In selected systems, this increase may be explained by increase in SOM content. However, the SOM quality places a role: the rise in organic compound - soil interactions may both exceed the SOM content increase and be less than that. Sorption interactions of herbicides with soils demonstrate a strong hysteresis (which is not expected to be related to a biodegradation). The data suggests that the OMWW - soil interaction seems to change the shape of the apparent sorption isotherms of organic sorbates, and, possibly, their sorption mechanisms: from a Langmuir-like sorption isotherm (describing the adsorptive interactions with a saturation of sorption sites) in the native soils to the sigmoidal or linear isotherms (expected for a partitioning into the bulk OM phases and their swelling) in the OMWW-amended soils. These results may have a significant impact on multiple agricultural and hydrological aspects, e.g., such as the application rate of herbicides in the field, and their possible release and the long term effect on groundwater. The authors acknowledge the support from the OLIVEOIL project (SCHA849/13) funded by DFG.

Season mediates herbivore effects on litter and soil microbial abundance and activity in a semi-arid woodland

DOE Office of Scientific and Technical Information (OSTI.GOV)

Classen, Aimee T; Overby, Stephen; Hart, Stephen C

2007-01-01

Herbivores can directly impact ecosystem function by altering litter quality entering an ecosystem or indirectly by affecting a shift in the microbial community that mediate nutrient processes. We examine herbivore susceptibility and resistance effects on litter microarthropod and soil microbial communities to test the general hypothesis that herbivore driven changes in litter inputs will feedback to the microbial community. Our study population consisted of individual trees that are susceptible or resistant to the stem-boring moth (Dioryctria albovittella) and trees that herbivores have been manually removed since 1982. Moth herbivory increased pi on litter nitrogen concentrations (16%) and canopy precipitation infiltrationmore » (28%), both significant factors influencing litter and soil microbial populations. Our research resulted in three major conclusions: 1) In spite of an increase in litter quality, herbivory does not change litter microarthropod abundance or species richness. 2) Herbivore susceptibility alters bulk soil microbial communities, but not soil properties. 3) Season has a strong influence on microbial communities, and their response to herbivore inputs, in this semi-arid ecosystem.« less

Distribution of YLOID in soil-grapevine system (Vitis vinifera L.) as tool for geographical characterization of agro-food products. A two years case study on different grafting combinations.

PubMed

Pisciotta, Antonino; Tutone, Livia; Saiano, Filippo

2017-04-15

The knowledge of a chemistry relationship between the soil and the agricultural products is an important tool for the quality assessment of food. We studied YLOID (Y, La and lanthanoids), recognized as very useful tracers due their coherent and predictable behavior, to trace and evaluate their distribution from soil to the grape in Vitis vinifera L. Because much of the world's viticulture is based on grafting, and rootstocks have proved affect vine growth, yield, fruit and wine quality, we carried out experimental trials to analyse the YLOID distribution of two different red cultivars, grafted onto six different rootstocks, on the same soil. The YLOID amounts, the relationship Heavy vs Light YLOID and the pattern of YLOID were calculated. The results showed that the different grafting combinations were not able to induce significant differences in YLOID uptake from the soil maintaining the same fingerprint (with the exception of Eu). Copyright © 2016 Elsevier Ltd. All rights reserved.

Soil organic matter as sole indicator of soil degradation.

PubMed

Obalum, S E; Chibuike, G U; Peth, S; Ouyang, Y

2017-04-01

Soil organic matter (SOM) is known to play vital roles in the maintenance and improvement of many soil properties and processes. These roles, which largely influence soil functions, are a pool of specific contributions of different components of SOM. The soil functions, in turn, normally define the level of soil degradation, viewed as quantifiable temporal changes in a soil that impairs its quality. This paper aims at providing a generalized assessment of the current state of knowledge on the usefulness of SOM in monitoring soil degradation, based on its influence on the physical, chemical and biological properties and processes of soils. Emphasis is placed particularly on the effect of SOM on soil structure and availability of plant nutrients. Although these properties are discussed separately, the soil system is of dynamic and interactive nature, and changes in one property will likely affect other soil properties as well. Thus, functions of SOM almost always affect various soil properties and processes and engage in multiple reactions. In view of its role in soil aggregation and erosion control, in availability of plant nutrients and in ameliorating other forms of soil degradation than erosion, SOM has proven to be an important indicator of soil degradation. It has been suggested, however, that rather than the absolute amount, temporal change and potential amount of SOM be considered in its use as indicator of soil degradation, and that SOM may not be an all-purpose indicator. Whilst SOM remains a candidate without substitute as long as a one-parameter indicator of soil degradation is needed, narrowing down to the use of its labile and microbial components could be more appropriate, since early detection is important in the control and management of soil degradation.

Changes in growth, essential oil yield and composition of geranium (Pelargonium graveolens L.) as affected by growing media.

PubMed

Rezaei Nejad, Abdolhossein; Ismaili, Ahmad

2014-03-30

Using proper growing medium is known to be an effective way to improve crop growth and yield. However, the effects of growing media on geranium essential oil have scarcely ever been examined in detail. In this research, the effects of different growing media (soil, sand, pumice, perlite and perlite + cocopeat) on growth, oil yield and composition of geranium were studied. Growth was significantly improved in soilless-grown plants compared with soil-grown plants. Oil yield of soilless-grown plants (except for pumice) was about threefold higher than that of soil-grown plants. The increase in oil yield was correlated with higher leaf dry weight (r²  = 0.96), as oil content was not affected. The citronellol/geranium ratio of oil was clearly affected by growing media, ranging from 5:1 in soil culture to 3:1 in soilless culture. The latter is acceptable for perfumery. Compared with soil, soilless media could produce higher yields of high-quality geranium oil that fits market requirements. Growth, oil yield and composition of plants grown in sand (a cheap and abundant growing medium) were not significantly different from those of plants grown in perlite and perlite + cocopeat. © 2013 Society of Chemical Industry.

Does management intensity in inter rows effect soil physical properties in Austrian and Romanian vineyards?

NASA Astrophysics Data System (ADS)

Bauer, Thomas; Strauss, Peter; Stiper, Katrin; Klipa, Vladimir; Popescu, Daniela; Winter, Silvia; Zaller, Johann G.

2016-04-01

Successful viticulture is mainly influenced by soil and climate. The availability of water during the growing season highly influences wine quality and quantity. To protect soil from being eroded most of the winegrowers keep the inter row zones of the vineyards green. Greening also helps to provide water-stress to the grapes for harvesting high quality wines. However, these greening strategies concerning the intensity of inter row management differ from farm to farm and are mainly based on personal experience of the winegrowers. However to what extent different inter row management practices affect soil physical properties are not clearly understood yet. To measure possible effects of inter row management in vineyards on soil physical parameters we selected paired vineyards with different inter row management in Austria and Romania. In total more than 7000 soil analysis were conducted for saturated and unsaturated hydraulic conductivity, soil water retention, water stable aggregates, total organic carbon, cation exchange capacity, potassium, phosphorous, soil texture, bulk density and water infiltration. The comparison between high intensity management with at least one soil disturbance per year, medium intensity with one soil disturbance every second inter row per year and low intensity management with no soil disturbance since at least 5 years indicates that investigated soil physical properties did not improve for the upper soil layer (3-8cm). This is in contrast to general perceptions of improved soil physical properties due to low intensity of inter row management, i.e. permanent vegetated inter rows. This may be attributed to long term and high frequency mechanical stress by agricultural machinery in inter rows.

Topography effect on soil organic carbon pool in Mediterranean natural areas (Southern Spain)

NASA Astrophysics Data System (ADS)

Parras-Alcántara, Luis; Lozan-García, Beatriz; Galán-Espejo, Arantxa

2014-05-01

Soils are important reservoirs of carbon, in fact, the primary terrestrial pool of organic carbon (OC) that accounts more than 75% of the Earth's terrestrial OC are the soils. In addition, soils have the ability to store carbon for a long time, playing a crucial role in the overall carbon cycle. In Spanish soils, climate, use and management are very influential in the carbon variability, mainly in the soils in Mediterranean dry climate, characterized by its low OC content, weak structure and readily degradable. Generally, the capacity to soil carbon store depends on abiotic factors such as the climate and mineralogical composition, but also depends on soil use and management. The principal factors that affect to forest soils carbon concentration and stock are: climate, landscape, landscape position, slope, latitude, chemical properties, texture and aggregation, anthropogenic factors, natural disturbance - wind, fire, drought, insects and diseases…etc. The soil organic matter (SOM), given by the total organic carbon content (TOC) is one of the main indicators of soil quality. Several studies have been carried out to estimate differences in SOC in relation to soil properties, land uses and climate. Although the impact of topographic aspect on soil properties is widely recognized, relatively few studies have been conducted to examine the role of aspect on SOC content globally. Studies indicate some variations in soil properties related to topographic. Topographic aspect induces local variation in temperature and precipitation solar radiation and relative humidity, which along with chemical and physical composition of the substrate, are the main regulators of decomposition rates of SOM. The spatial variation of soil properties is significantly influenced by some environmental factors such as topographic aspect that induced microclimate differences, topographic (landscape) positions, parent materials, and vegetation communities. Many attempts have been made to quantify the relationships between topographical parameters and soil properties. Researchers suggested some promising indicators such as pH, organic matter, exchangeable cations, total exchangeable basis, ratio of primary to secondary minerals, free oxides, carbonates and physical properties such as, particle size distribution, moisture content, color, bulk density and depth to specific horizon. If we considered SOC and TN how indicators of soil quality it is necessary to explain the relationship between the soil properties and topographic position, furthermore, is necessary establish indicator of the soil quality. In this regard, the stratification ratio (SR) is the most used. Soil development in this region is genetically complicated by three important soil forming factors: relief, fragility of this environment and absence of good vegetation (erosion by water) and the use and management (CT). Very little literature is published on soil variability and its relationship with topographic positions within such fragile environment. There are few reports on stratification of the SOC, TN and C:N ratio as affected by topography in natural areas. In this context, the objectives of this study were; assess the SOC in the soils, its vertical distribution in the profile and analyze the accumulation and SR of SOC along a topographic gradient and their relationship to soil depth in arid Mediterranean climate in Spain.

Revegetation of the riparian zone of the Three Gorges Dam Reservoir leads to increased soil bacterial diversity.

PubMed

Ren, Qingshui; Li, Changxiao; Yang, Wenhang; Song, Hong; Ma, Peng; Wang, Chaoying; Schneider, Rebecca L; Morreale, Stephen J

2018-06-06

As one of the most active components in soil, bacteria can affect soil physicochemical properties, its biological characteristics, and even its quality and health. We characterized dynamics of the soil bacterial diversity in planted (with Taxodium distichum) and unplanted soil in the riparian zone of the Three Gorges Dam Reservoir (TGDR), in southwestern China, in order to accurately quantify the changes in long-term soil bacterial community structure after revegetation. Measurements were taken annually in situ in the TGDR over the course of 5 years, from 2012 to 2016. Soil chemical properties and bacterial diversity were analyzed in both the planted and unplanted soil. After revegetation, the soil chemical properties in planted soil were significantly different than in unplanted soil. The effects of treatment, time, and the interaction of both time and treatment had significant impacts on most diversity indices. Specifically, the bacterial community diversity indices in planted soil were significantly higher and more stable than that in unplanted soil. The correlation analyses indicated that the diversity indices correlated with the pH value, organic matter, and soil available nutrients. After revegetation in the riparian zone of the TGDR, the soil quality and health is closely related to the observed bacterial diversity, and a higher bacterial diversity avails the maintenance of soil functionality. Thus, more reforestation should be carried out in the riparian zone of the TGDR, so as to effectively mitigate the negative ecological impacts of the dam. Vegetating the reservoir banks with Taxodium distichum proved successful, but planting mixed stands of native tree species could promote even higher riparian soil biodiversity and improved levels of ecosystem functioning within the TGDR.

Effect of desertification on productivity in a desert steppe.

PubMed

Tang, Zhuangsheng; An, Hui; Deng, Lei; Wang, Yingying; Zhu, Guangyu; Shangguan, Zhouping

2016-06-14

Desertification, one of the most severe types of land degradation in the world, is of great importance because it is occurring, to some degree, on approximately 40% of the global land area and is affecting more than 1 billion people. In this study, we used a space-for-time method to quantify the impact of five different desertification regimes (potential (PD), light (LD), moderate (MD), severe (SD), and very severe (VSD)) on a desert steppe ecosystem in northern China to examine the relationship between the productivity of the vegetation and soil properties and to determine the mechanism underlying the effects of desertification on productivity. Our results showed that the effects of desertification on TP (total phosphorus) and AP (available phosphorus) were not significant, and desertification decreased productivity in the desert steppe as a result of direct changes to soil physical properties, which can directly affect soil chemical properties. Therefore, intensive grassland management to improve soil quality may result in the long-term preservation of ecosystem functions and services.

Effect of desertification on productivity in a desert steppe

PubMed Central

Tang, Zhuangsheng; An, Hui; Deng, Lei; Wang, Yingying; Zhu, Guangyu; Shangguan, Zhouping

2016-01-01

Desertification, one of the most severe types of land degradation in the world, is of great importance because it is occurring, to some degree, on approximately 40% of the global land area and is affecting more than 1 billion people. In this study, we used a space-for-time method to quantify the impact of five different desertification regimes (potential (PD), light (LD), moderate (MD), severe (SD), and very severe (VSD)) on a desert steppe ecosystem in northern China to examine the relationship between the productivity of the vegetation and soil properties and to determine the mechanism underlying the effects of desertification on productivity. Our results showed that the effects of desertification on TP (total phosphorus) and AP (available phosphorus) were not significant, and desertification decreased productivity in the desert steppe as a result of direct changes to soil physical properties, which can directly affect soil chemical properties. Therefore, intensive grassland management to improve soil quality may result in the long-term preservation of ecosystem functions and services. PMID:27297202

Phytostabilisation with Mediterranean shrubs and liming improved soil quality in a pot experiment with a pyrite mine soil.

PubMed

Moreno-Jiménez, Eduardo; Esteban, Elvira; Carpena-Ruiz, Ramón O; Lobo, María Carmen; Peñalosa, Jesús M

2012-01-30

Phytoremediation can be a suitable option to manage derelict mine soils. A pot experiment was carried out under semi-controlled conditions with a mine-impacted soil. A further contamination event was mimicked by applying 5% of pyritic sludge. Four species were planted in pots (Myrtus communis, Retama sphaerocarpa, Rosmarinus officinalis and Tamarix gallica), and some pots remained unplanted as a control. The substrates were moderately to highly contaminated, mainly with arsenic and zinc. The strong acidification induced by the pyritic sludge was buffered with lime and plants survived in all the pots. Liming provoked an effective immobilisation of metals and arsenic. Plant establishment decreased labile As in the substrate by 50%, mainly M. communis, although the levels of extractable metals were not affected by the plants. R. sphaerocarpa and M. communis increased the levels of C and N in the soil by 23% and 34% respectively, and also enhanced enzymatic activities and microbial respiration to the double in some cases. The low transfer of trace elements to shoots limited the phytoextraction rate. Our results support the use of phytostabilisation in Mediterranean mine soils and show how plants of R. sphaerocarpa and M. communis may increase soil health and quality during revegetation. Copyright © 2011 Elsevier B.V. All rights reserved.

Multivariate statistical analysis of heavy metal concentration in soils of Yelagiri Hills, Tamilnadu, India--spectroscopical approach.

PubMed

Chandrasekaran, A; Ravisankar, R; Harikrishnan, N; Satapathy, K K; Prasad, M V R; Kanagasabapathy, K V

2015-02-25

Anthropogenic activities increase the accumulation of heavy metals in the soil environment. Soil pollution significantly reduces environmental quality and affects the human health. In the present study soil samples were collected at different locations of Yelagiri Hills, Tamilnadu, India for heavy metal analysis. The samples were analyzed for twelve selected heavy metals (Mg, Al, K, Ca, Ti, Fe, V, Cr, Mn, Co, Ni and Zn) using energy dispersive X-ray fluorescence (EDXRF) spectroscopy. Heavy metals concentration in soil were investigated using enrichment factor (EF), geo-accumulation index (Igeo), contamination factor (CF) and pollution load index (PLI) to determine metal accumulation, distribution and its pollution status. Heavy metal toxicity risk was assessed using soil quality guidelines (SQGs) given by target and intervention values of Dutch soil standards. The concentration of Ni, Co, Zn, Cr, Mn, Fe, Ti, K, Al, Mg were mainly controlled by natural sources. Multivariate statistical methods such as correlation matrix, principal component analysis and cluster analysis were applied for the identification of heavy metal sources (anthropogenic/natural origin). Geo-statistical methods such as kirging identified hot spots of metal contamination in road areas influenced mainly by presence of natural rocks. Copyright © 2014 Elsevier B.V. All rights reserved.

Shrubs stimulate heterotrophic respiration in arctic soils

NASA Astrophysics Data System (ADS)

Phillips, C. A.; Wurzburger, N.

2016-12-01

The response of arctic ecosystems to global change will have critical effects on future climate. Climate warming has already triggered the expansion of shrubs across tundra, raising questions about how shrubs will affect ecosystem carbon balance. Shrub litter quality and mycorrhizal symbionts may accelerate the activity of soil microorganisms that facilitate the release of large stores of soil carbon. We investigated how shrubs affect the activity of soil microorganisms by creating soil mesocosms from areas with and without shrub species as dominants of the plant community in arctic Alaska. We hypothesized that relative to their non-shrub counterparts, heterotrophic respiration of shrub soils would: (1) be greater, (2) demonstrate greater response to additions of shrub litter, and (3) be less nutrient limited. We created mesocosms with root-free soils at constant moisture and temperature, and quantified basal heterotrophic soil respiration rates, and the response of respiration to litter and nutrient inputs in a series of laboratory experiments inputs. (1) We found that the presence of shrubs generally produced higher rates of basal soil respiration in both horizons, suggesting that shrubs stimulate microbial activity. (2) Litter addition increased respiration across both horizons with no differences in response between shrub and non-shrub soils. (3) N additions did not increase heterotrophic respiration, but P and N+P additions induced a short respiratory pulse in all soils, suggesting mild P limitation. Collectively, these findings provide evidence that shrubs stimulate heterotrophic microbial activity to enhance carbon loss, but generate new questions about the mechanisms driving these patterns.

Impact of Ca-amendments and soil management in physical properties linked to soil-water relationship in degraded Ultisols from South-Europe

NASA Astrophysics Data System (ADS)

Mariscal-Sancho, I.; Gonzalez-Fernandez, P.; León, P.; Gómez-Paccard, C.; Benito, M.; Espejo, R.

2012-04-01

Cañamerós raña formation in western Spain was cleared for cropping in 1940´s. Its highly weathered acidic soils (Ultisols) were deeply affected by tillage. The soil organic matter (SOM) content and specially the particulate organic matter (POM), a labile fraction, were drastically reduced, and most of their chemical and physical soil properties related to its quality were negatively affected. The extraction of Ca through the harvest and the release of Al retained in organic-Al complexes resulted in a lower Ca/Al ratio which increased the Al toxicity. These effects led to a drastic yield reduction and the abandon of many degraded fields after 20-70 years of unsustainable managements. On these degraded soils we studied the effect of different soil management strategies (no-till with wild pasture (WP) and no-till with an improved pasture (IP)), and amendment applications (sugar foam waste (SF), and SF + Phosphogypsum (PH) versus control (C)). One of the objectives of this work was to evaluate the efficiency of these practices to recover soil quality parameters, especially those related to soil-water relationship. A Split-plot experiment was established in a degraded field. We evaluated the changes in superficial infiltration, bulk density, and content of water-stable aggregates per 100 g of soil before the Ca-amendment applications and pasture establishments, and after 4.5 years. We also measured the changes in SOM and POM contents which are closely related with the previous parameters. The Ca applications reduced Al toxicity, improved the pasture yield and increased organic matter inputs to soil. The results showed a significant increase of POM in all treatment compared with the POM content at the beginning of this experiment. However the "SOM minus POM" which could be classified as recalcitrant organic matter did not show significant increments. The increase of POM had a positive effect on the content of water-stable aggregates per 100 g of soil and the water infiltration which increased, and the bulk density which decreased. We recommend the use of SF for these degraded acid soils, because it improved soil-water properties and because it is a clean and inexpensive by-product. The IP cropping also assisted the soil recovery and provided pastures with higher concentration of legumes species than the WP.

Invasion of Impatiens glandulifera affects terrestrial gastropods by altering microclimate

NASA Astrophysics Data System (ADS)

Ruckli, Regina; Rusterholz, Hans-Peter; Baur, Bruno

2013-02-01

Invasive species can have far-reaching impacts on ecosystems. Invasive plants may be able to change habitat structure and quality. We conducted a field experiment to examine whether the invasive plant Impatiens glandulifera affects native terrestrial gastropods. We also evaluated whether the invasive plant alters forest soil characteristics and microclimate which in turn may influence gastropod abundance. We sampled gastropods in plots installed in patches of I. glandulifera, in plots in which I. glandulifera was regularly removed by hand, and in control plots which were not yet colonized by the invasive plant. The three types of plots were equally distributed over three mixed deciduous forest areas that were slightly, moderately or heavily affected by a wind throw 11 years ago. A total of 33 gastropod species were recorded. Gastropod species richness was not affected by delayed effects of the wind throw, but it was significantly higher in invaded plots than in uninvaded plots. Similarly, gastropod abundance was higher in invaded plots than in the two types of control plots. Canonical correspondence analysis revealed marginally significant shifts of gastropod communities between the three types of plots and indicated that soil moisture, presence of I. glandulifera and cover of woody debris affected gastropod species composition. Field measurements showed that soil moisture was higher and daily soil temperature was more damped in patches of I. glandulifera than in the native ground vegetation. The changed microclimatic conditions may favour certain gastropod species. In particular, ubiquitous species and species with a high inundation tolerance increased in abundance in plots invaded by I. glandulifera. Our field experiment demonstrated that an invasive plant can indirectly affect native organisms by changing soil characteristics and microclimate.

Wildfire effects on C stocks in mountain soils

NASA Astrophysics Data System (ADS)

Menéndez-Duarte, R.; Fernández, S.; Santin, C.; Gaspar, L.; Navas, A.

2012-04-01

Wildfire is the main perturbation agent in mountain soils of the Cantabrian Range (NW of Spain). Fire affects soil organic carbon (SOC) quality and quantity, both directly (e.g. combustion of organic matter and pyrogenic carbon production) and indirectly (e.g. increase of soil erosion and change of the vegetation cover). After fire, the organic fraction of the soil is expected to be enriched with charred compounds (black carbon, biochar or pyrogenic carbon-PyC). PyC mainly contributes to the recalcitrant C pool and therefore to the medium- and long-term C sequestration in soils. Moreover, recurrent fires in these Atlantic mountain ecosystems cause the conversion of the vegetation cover from forest to heathland, altering C transfer from biomass to soil. On the other hand, in this steep terrain, fire enhances soil erosion by creeping and therefore soil loss and the consequent loss of SOC. Thus, a basic but fundamental question arises: which is the net variation of SOC stocks in these mountain soils due to wildfires? To answer this, soils were sampled in a typical quartzite steep mountain in the Somiedo Natural Park (NW of Spain): i) a transect in the South hillside, prone to fires and with an intense fire history, where the vegetation cover is mostly heather and gorse; and ii) a transect in the North hillside, less affected by fire and with a well preserved vegetation cover (beech and oak forest). Samples of the surface soil (0-5 cm) and the whole soil profile were taken and, bulk density and SOC content were determined. On average fire-affected soils in the South transect have a lower soil depth (12.0 cm) and lower bulk density (0.5 g/cm3) than the North transect soils (17.6 cm depth and 1.0 g/cm3 bulk density) but they have also SOC concentrations six times higher than their unburned counterparts (147.5 and 22.8 mg C/g soil, respectively). When considering SOC stocks, differences are not as pronounced but, even so, fire affected soils content twice as much SOC (7.4 kg /m2) than the unburned soils (3.2 kg SOC/m2). Characterisation of SOC is being carried out by thermogravimetry-differential scanning calorimetry to identify the qualitative differences of SOC in burned and unburned soils and to quantify the proportion of PyC, which may play a main role in the potential of these mountain soils as long-term C reservoirs.

Effects of non-native earthworms on on below- and aboveground processes in the Mid-Atlantic region

NASA Astrophysics Data System (ADS)

Szlavecz, K. A.; McCormick, M. K.; Xia, L.; Pitz, S.; O'Neill, J.; Bernard, M.; Chang, C.; Whigham, D. F.

2011-12-01

Many biotic and abiotic disturbances have shaped the structure of the deciduous forests in the Mid-Atlantic region. One major anthropogenic factor is land use history. Agricultural practices in the past undoubtedly facilitated non-native earthworm colonization and establishment. Today most secondary forests are dominated by European lumbricid earthworms, although native species also occur in some habitats. To investigate how earthworm community composition and abundance affect belowground processes and tree seedling growth we set up a field manipulation experiment at the Smithsonian Environmental Research Center in Edgewater, MD. A total of 66 experimental plots were set up in successional (70 yrs) and mature (150 yrs) Tulip-poplar-Oak associations. We manipulated earthworm abundance and leaf litter input, and planted seedlings of Tulip poplar, Red maple, Red oak, and American beech. The experiment lasted for two years during which we regularly monitored density, biomass and species composition of earthworm assemblages and measured soil respiration. Soil moisture, temperature and air temperature were also continuously monitored using a wireless sensor network. At harvest, soil bulk density, pH, N pools, C:N ratio, potential N-mineralization rates, and enzyme activity were determined. We used quantitative PCR to assess the community composition of soil fungi. We also determined the extent of mycorrhizal colonization and biomass of roots, shoots and leaves. We conducted likelihood ratio tests for random and fixed effects based on mixed model analyses of variance. Differences between soil depths and among sites and plots accounted for a large portion of the variation in many soil properties. Litter quality affected soil pH and N mineralization. Earthworm densities affected bulk density, inorganic N content, and N mineralization. Both mycorrhizal groups were more abundant in mature than in successional forests. Both ectomycorrhizal (ECM) and arbuscular (AM) fungi were less abundant in the earthworm removal plots. There was a significant positive earthworm effect on the rate and thermal sensitivity of soil respiration. Soil respiration was consistently higher in plots with tulip poplar litter than those with beech litter, indicating a strong influence of plant residue quality. However, the differences were smaller in the second year than in the first one indicating an adaptation of the soil system. Oak and beech seedlings were smaller in high density earthworm plots, while the reverse was true for maple and tulip poplar seedlings. Non-native earthworms affect below- and aboveground processes, however, these effects depend on forest type and land use history. The earthworm effects also appear to be dynamic, as witnessed by a recent invasion of an Asian earthworm species in one of our forest stands.

Identification of Soil Properties and Organophosphate Residues From Agricultural Land in Wanasari Sub-District, Brebes, Indonesia

NASA Astrophysics Data System (ADS)

Joko, Tri; Anggoro, Sutrisno; Sunoko, Henna Rya; Rachmawati, Savitri

2018-02-01

Organophosphates have been used to eradicate pests and prevent losses from harvest failures caused by pest attack. It is undeniable that the organophosphate persist in soil. This study aims to identify the organophosphate residue and soil properties include pH, soil texture, and permeability. The soil samples were taken from cropland in 10 villages, Wanasari sub-district, Brebes, Indonesia. Organophosphate residue determined by gas chromatography using Flame Photometric Detector. Soil texture was determined by soil texture triangle from NRCS USDA, and the permeability value was determined by falling head method. The mean value of chlorpyrifos, profenofos, diazinon were 0.0078; 0.0388; 0.2271 mg/l respectively. The soil texture varies from clay, silt clay, loam, silt loam, and silt clay loam with permeability value at 10-7 with the soil pH value between 6.4 - 8.1. The results showed that organophosphate residues found in the soil and its potential affect the soil fertility decline. We recommend to conduct routine soil quality analysis to prevent soil damage in the agricultural environment.

Reciprocal Effects of Litter from Exotic and Congeneric Native Plant Species via Soil Nutrients

PubMed Central

Meisner, Annelein; de Boer, Wietse; Cornelissen, Johannes H. C.; van der Putten, Wim H.

2012-01-01

Invasive exotic plant species are often expected to benefit exclusively from legacy effects of their litter inputs on soil processes and nutrient availability. However, there are relatively few experimental tests determining how litter of exotic plants affects their own growth conditions compared to congeneric native plant species. Here, we test how the legacy of litter from three exotic plant species affects their own performance in comparison to their congeneric natives that co-occur in the invaded habitat. We also analyzed litter effects on soil processes. In all three comparisons, soil with litter from exotic plant species had the highest respiration rates. In two out of the three exotic-native species comparisons, soil with litter from exotic plant species had higher inorganic nitrogen concentrations than their native congener, which was likely due to higher initial litter quality of the exotics. When litter from an exotic plant species had a positive effect on itself, it also had a positive effect on its native congener. We conclude that exotic plant species develop a legacy effect in soil from the invaded range through their litter inputs. This litter legacy effect results in altered soil processes that can promote both the exotic plant species and their native congener. PMID:22359604

The use of a hydrological physically based model to evaluate the vine adaptability to future climate: the case study of a Protected Designation of Origin area (DOC and DOCG) of Southern Italy

NASA Astrophysics Data System (ADS)

Bonfante, Antonello; Basile, Angelo; Menenti, Massimo; Monaco, Eugenia; Alfieri, Silvia Maria; Manna, Piero; Langella, Giuliano; De Lorenzi, Francesca

2013-04-01

The quality of grape and wine is variety-specific and depends significantly on the pedoclimatic conditions, thus from the terroir characteristics. In viticulture the concept of terroir is known to be very complex. At present some changes are occurring in the studies of terroir. Their spatial analysis is improving by means of studies that account for the spatial distribution of solar radiation and of bioclimatic indexes. Moreover, simulation models are used to study the water flow in the soil-plant-atmosphere system in order to determine the water balance of vines as a function of i) soil physical properties, ii) climatic regime and iii) agro-ecosystems characteristics. The future climate evolution may endanger not only yield production (IPCC, 2007), but also its quality. The effects on quality may be relevant for grape production, since they can affect the sustainability of the cultivation of grape varieties in the areas where they are currently grown. This study addresses this question by evaluating the adaptive capacity of grape's cultivars in a 20000 ha viticultural area in the "Valle Telesina" (Campania Region, Southern Italy). This area has a long tradition in the production of high quality wines (DOC and DOCG) and it is characterized by a complex geomorphology with a large variability of soils and micro-climate. Two climate scenarios were considered: "past" (1961-1990) and "future" (2021-2050), the latter constructed applying statistical downscaling to GCMs scenarios. For each climate scenario the moisture regime of the soils of the study area was calculated by means of a simulation model of the soil-water-atmosphere system (SWAP). The hydrological model SWAP was applied to the representative soils of the entire area (47 soil units); the soil hydraulic properties were estimated (by means of pedo-transfer function HYPRES) and measured. Upper boundary conditions were derived from the climate scenarios. Unit gradient in soil water potential was set as lower boundary condition. Crop-specific input data and model parameters were estimated on the basis of scientific literature and assumed to be generically representative of the species. Synthetic indicators of the regimes (e.g. crop evapotranspiration deficit - CWSI, available soil water content, soil temperature) were calculated and compared with thermal and water requirements of a set of grape varieties, including the ones currently cultivated in the area. As a result of the comparison, most varieties resulted adaptable to the future climate. For some cultivars (i.e. Catalanesca) a significant increase of suitable area is foreseen; in other cases (i.e. Aglianico and Falanghina) a slight reduction will occur. Moreover for the most important varieties actually cultivated (e.g. Aglianico, Falanghina, etc.) an analysis on the expected spatial migration due to the climate change was performed. Finally, an analysis of CWSI during different crop phenological stages was performed for both climate periods . The time course of the moisture regime in different soils was thus described; this analysis allowed to identify the soils where the water regime can positively affect grape (and wine) quality . The work was carried out within the Italian national project AGROSCENARI funded by the Ministry for Agricultural, Food and Forest Policies (MIPAAF, D.M. 8608/7303/2008)

Identification of vulnerable sites in salts affected agricultural soils from South-Eastern Spain

NASA Astrophysics Data System (ADS)

Acosta, Jose A.; Faz, Angel; Kalbitz, Karsten; Jansen, Boris; Silvia, Martinez-Martinez

2010-05-01

Soil salinization is one of the main problems in many soils under intensive agricultural practices, especially in arid and semiarid zones. Two important reasons for the occurrence of salinization are i) the use of low quality irrigation water and ii) climatic conditions reducing soil quality. The results of salinization can be quite serious. It limits the growing of crops, constrains agricultural productivity, and in severe cases, leads to the abandonment of agricultural soils. There are mainly two kinds of soil salinity: naturally occurring dry-land salinity and human-induced salinity caused by the low quality of irrigation water, excessive water and fertilizer applications. In both cases the development of plants and soil organisms is limited. Natural occurrence of salts in soils is very difficult to handle and requires higher investments than the reduction of human-induced salinity. For these reasons, identification of vulnerable sites is essential for sustainable agricultural management, especially in these semiarid and arid environments. The main aim of this study was to examine spatial and vertical distribution pattern of salts in a semi-arid study site in South-Eastern Spain in order to identify vulnerable sites. In order to achieve this objective, surface soil samples were collected in January and July 2009 at 48 sites located in a representative lemon production area close to City of Murcia, covering a surface area of 44 km2. The area was divided using a square grid of 1000 m and the samples were taken from these squares. The ionic concentrations were used as the input data for distribution maps. The software used for the spatial analysis was Arcview 3.1. An interpolation method called the Inverse Distanced Weighted (IDW) method was adopted for the interpolation of the data. The results indicated that the concentrations of most anions are higher in summer. The difference was particularly large for chloride, most likely because of its high mobility and little adsorption to soil colloidal particles. However, other ions such as sulfate, calcium, magnesium, and sodium also displayed significant increases in concentration in July. This can be explained by the movements of soluble salt to the surface due to evaporation and capillary rise and subsequent precipitation of the salts during high temperatures and low rainfall. Rainfall or irrigation events enhance the leaching of salts to deeper soil horizons. The most affected area is located in the west of the study area, at the lowest altitude within the study area. Depressions favour accumulation of salts, due to both runoffs from higher areas during rainfall periods and poor quality irrigation water. It is recommended to use a better quality of water, at least before the summer, in order to reduce the amount of salts in the surface layer, likely to cause stress to crops growing on the soil in question. In conclusion, the spatial distribution of anions in the soil solution is very useful for predicting where higher increases in salinity will be produced. This will allow for identification of vulnerable areas and subsequent implementation of the necessary measures to decrease the risk for sensitive crops. Acknowledgements: to "Fundación Séneca" of "Comunidad Autónoma de Murcia" for its financial support.

Flux rates of atmospheric lead pollution within soils of a small catchment in northern Sweden and their implications for future stream water quality.

PubMed

Klaminder, Jonatan; Bindler, Richard; Laudon, Hjalmar; Bishop, Kevin; Emteryd, Ove; Renberg, Ingemar

2006-08-01

It is not well-known how the accumulated pool of atmospheric lead pollution in the boreal forest soil will affect the groundwater and surface water chemistry in the future as this lead migrates through the soil profile. This study uses stable lead isotopes (206Pb/207Pb and 208Pb/ 207Pb ratios) to trace the transport of atmospheric lead pollution within the soil of a small catchment and predict future lead level changes in a stream draining the catchment. Low 206Pb/207Pb and 208Pb/207Pb ratios for the lead in the soil water (1.16 +/- 0.02; 2.43 +/- 0.03) and streamwater (1.18 +/- 0.03; 2.42 +/- 0.03) in comparison to that of the mineral soil (>1.4; >2.5) suggest that atmospheric pollution contributes by about 90% (65-100%) to the lead pool found in these matrixes. Calculated transport rates of atmospheric lead along a soil transect indicate that the mean residence time of lead in organic and mineral soil layers is at a centennial to millennial time scale. A maximum release of the present pool of lead pollution in the soil to the stream is predicted to occur within 200-800 years. Even though the uncertainty of the prediction is large, it emphasizes the magnitude of the time lag between the accumulation of atmospheric lead pollution in soils and the subsequent response in streamwater quality.

Changes in microbial community characteristics and soil organic matter with nitrogen additions in two tropical forests.

PubMed

Cusack, Daniela F; Silver, Whendee L; Torn, Margaret S; Burton, Sarah D; Firestone, Mary K

2011-03-01

Microbial communities and their associated enzyme activities affect the amount and chemical quality of carbon (C) in soils. Increasing nitrogen (N) deposition, particularly in N-rich tropical forests, is likely to change the composition and behavior of microbial communities and feed back on ecosystem structure and function. This study presents a novel assessment of mechanistic links between microbial responses to N deposition and shifts in soil organic matter (SOM) quality and quantity. We used phospholipid fatty acid (PLFA) analysis and microbial enzyme assays in soils to assess microbial community responses to long-term N additions in two distinct tropical rain forests. We used soil density fractionation and 13C nuclear magnetic resonance (NMR) spectroscopy to measure related changes in SOM pool sizes and chemical quality. Microbial biomass increased in response to N fertilization in both tropical forests and corresponded to declines in pools of low-density SOM. The chemical quality of this soil C pool reflected ecosystem-specific changes in microbial community composition. In the lower-elevation forest, there was an increase in gram-negative bacteria PLFA biomass, and there were significant losses of labile C chemical groups (O-alkyls). In contrast, the upper-elevation tropical forest had an increase in fungal PLFAs with N additions and declines in C groups associated with increased soil C storage (alkyls). The dynamics of microbial enzymatic activities with N addition provided a functional link between changes in microbial community structure and SOM chemistry. Ecosystem-specific changes in microbial community composition are likely to have far-reaching effects on soil carbon storage and cycling. This study indicates that microbial communities in N-rich tropical forests can be sensitive to added N, but we can expect significant variability in how ecosystem structure and function respond to N deposition among tropical forest types.

Soil Microarthropods and Their Relationship to Higher Trophic Levels in the Pedregal de San Angel Ecological Reserve, Mexico

PubMed Central

Callejas-Chavero, Alicia; Castaño-Meneses, Gabriela; Razo-González, María; Pérez-Velázquez, Daniela; Palacios-Vargas, José G.; Flores-Martínez, Arturo

2015-01-01

Soil fauna is essential for ecosystem dynamics as it is involved in biogeochemical processes, promotes nutrient availability, and affects the animal communities associated with plants. In this study, we examine the possible relationship between the soil microarthropod community on foliage production and quality of the shrub Pittocaulon praecox. We also examine the arthropods associated to its foliage, particularly the size of the main herbivores and of their natural enemies, at two sites with contrasting vegetation cover and productivity. The diversity of soil microarthropods was assessed from soil samples collected monthly under P. praecox individuals over 13 mo. Specimens collected were identified to species or morphospecies. Shrub foliage productivity was evaluated through the amount of litter produced. Resource quality was assessed by the mean content (percentage by weight) of N, C, S, and P of 30 leaves from each shrub. The mean size of herbivores and their natural enemies were determined by measuring 20 adult specimens of each of the most abundant species. We found a higher species richness of soil microarthropods and foliar arthropods in the open site, although the diversity of foliage arthropods was lower in the closed site. Shrubs growing in the closed site tend to produce more, larger, and nutritionally poorer (lower nitrogen content) leaves than open site. Herbivores and their natural enemies were also larger in the closed site. We found a significant positive relationship between the diversity and species richness of foliar arthropods and the nitrogen content of leaves. In general, species richness and diversity of both the foliar and soil fauna, as well as the size of organisms belonging to higher trophic levels, were affected by vegetation cover and primary productivity at each site. These findings highlight the need to simultaneously consider at least four trophic levels (soil organisms, plants, herbivores, and natural enemies) to better understand the functioning of these systems and their responses to environmental changes. PMID:25978999

Impact of Soil Heavy Metal Pollution on Food Safety in China.

PubMed

Zhang, Xiuying; Zhong, Taiyang; Liu, Lei; Ouyang, Xiaoying

2015-01-01

Food safety is a major concern for the Chinese public. This study collected 465 published papers on heavy metal pollution rates (the ratio of the samples exceeding the Grade II limits for Chinese soils, the Soil Environmental Quality Standard-1995) in farmland soil throughout China. The results showed that Cd had the highest pollution rate of 7.75%, followed by Hg, Cu, Ni and Zn, Pb and Cr had the lowest pollution rates at lower than 1%. The total pollution rate in Chinese farmland soil was 10.18%, mainly from Cd, Hg, Cu, and Ni. The human activities of mining and smelting, industry, irrigation by sewage, urban development, and fertilizer application released certain amounts of heavy metals into soil, which resulted in the farmland soil being polluted. Considering the spatial variations of grain production, about 13.86% of grain production was affected due to the heavy metal pollution in farmland soil. These results many provide valuable information for agricultural soil management and protection in China.

Impact of Soil Heavy Metal Pollution on Food Safety in China

PubMed Central

Zhang, Xiuying; Zhong, Taiyang; Liu, Lei; Ouyang, Xiaoying

2015-01-01

Food safety is a major concern for the Chinese public. This study collected 465 published papers on heavy metal pollution rates (the ratio of the samples exceeding the Grade II limits for Chinese soils, the Soil Environmental Quality Standard-1995) in farmland soil throughout China. The results showed that Cd had the highest pollution rate of 7.75%, followed by Hg, Cu, Ni and Zn, Pb and Cr had the lowest pollution rates at lower than 1%. The total pollution rate in Chinese farmland soil was 10.18%, mainly from Cd, Hg, Cu, and Ni. The human activities of mining and smelting, industry, irrigation by sewage, urban development, and fertilizer application released certain amounts of heavy metals into soil, which resulted in the farmland soil being polluted. Considering the spatial variations of grain production, about 13.86% of grain production was affected due to the heavy metal pollution in farmland soil. These results many provide valuable information for agricultural soil management and protection in China. PMID:26252956

Assessing different agricultural managements with the use of soil quality indices in a Mediteranean calcareous soil

NASA Astrophysics Data System (ADS)

Morugán-Coronado, Alicia; García-Orenes, Fuensanta; Mataix-Solera, Jorge; Arcenegui, Vicky; Cerdà, Artemi

2013-04-01

Soil erosion is a major problem in the Mediterranean region due to the arid conditions and torrential rainfalls, which contribute to the degradation of agricultural land. New strategies must be developed to reduce soil losses and recover or maintain soil functionality in order to achieve a sustainable agriculture. An experiment was designed to evaluate the effect of different agricultural management on soil properties and soil quality. Ten different treatments (contact herbicide, systemic herbicide, ploughing, Oat mulch non-plough, Oats mulch plough, leguminous plant, straw rice mulch, chipped pruned branches, residual-herbicide and agro geo-textile, and three control plots including no tillage or control and long agricultural abandonment (shrub on marls and shrub on limestone) were established in 'El Teularet experimental station' located in the Sierra de Enguera (Valencia, Spain). The soil is a Typic Xerorthent developed over Cretaceous marls in an old agricultural terrace. The agricultural management can modify the soil equilibrium and affect its quality. In this work two soil quality indices (models) developed by Zornoza et al. (2007) are used to evaluate the effects of the different agricultural management along 4 years. The models were developed studying different soil properties in undisturbed forest soils in SE Spain, and the relationships between soil parameters were established using multiple linear regressions. Model 1, that explained 92% of the variance in soil organic carbon (SOC) showed that the SOC can be calculated by the linear combination of 6 physical, chemical and biochemical properties (acid phosphatase, water holding capacity (WHC), electrical conductivity (EC), available phosphorus (P), cation exchange capacity (CEC) and aggregate stability (AS). Model 2 explains 89% of the SOC variance, which can be calculated by means of 7 chemical and biochemical properties (urease, phosphatase, and ß-glucosidase activities, pH, EC, P and CEC). We use the residual (difference between calculated SOC by models and real SOC, analyzed in laboratory) as soil quality indices. We consider higher soil quality when the residuals are closer to cero or inside confidence intervals of the models (95%). As expected, the application of the models indicates that in all the treatments and the control plots (shrub on marls and shrub on limestone), the residuals are out of the confidence intervals for the models, showing a disequilibrium among soil properties because these treatments have been submitted to a perturbation such as the agricultural use. However, it can be observed that the residuals in the last sampling in control plots and some of the treatments, the least aggressive with the soil, are lower and therefore the soil it seems to the soil properties is achieving to their equilibrium among them. These soils are: Shrub on limestone and shrub on marls, Chipped pruned branches and Oat mulch non-plough. These results are in agreement with García-Orenes et al. (2010), who showed that the addition of oat straw to soil can be considered an effective soil management, because it produced an important increase of the different fractions of organic carbon and microbial activity, that it will be translated into a rapid improvement of soil quality. The application of the herbicides studied produced a decrease in all the soil parameters; these practices are not recommendable for a sustainable agricultural system in semiarid Mediterranean agro-ecosystem. -García-Orenes, F., Guerrero, C., Roldán, A., Mataix-Solera, J., Cerdà, A. Campoy, M., Zornoza, R., Bárcenas, G., Caravaca, F., (2010). Soil microbial biomass and activity under different agricultural management systems in a semiarid Mediterranean agroecosystem. Soil & Tillage Research 109: 110-115. -Zornoza, R., Mataix-Solera, J., Guerrero, C., Arcenegui, V., Mayoral, A.M., Morales, J. Mataix-Beneyto, J., 2007. Soil properties under natural forest in the Alicante Province of Spain. Geoderma. 142, 334-341 Aknowledgements: The authors acknowledge the 'Teularet experimental station' staff for the collaboration.

Evaluation of the sources of contamination in the suburban area of Koropi-Markopoulo, Athens, Greece.

PubMed

Kaitantzian, Agavni; Kelepertzis, Efstratios; Kelepertsis, Akindynos

2013-07-01

Heavy metal concentrations were monitored in agricultural soils and irrigation groundwaters of Koropi-Markopoulo area, a representative agricultural suburb in Athens, Greece, aiming at the identification of the sources of contaminants. Multivariate analyses of geochemical data demonstrated that agricultural practices and industrial activities considerably affected the quality of both environmental compartments. The levels of Ni, Cr, Co, Mn and Fe in agricultural soils were associated with geological parent materials whereas Pb, Zn and Cu mainly originated from anthropic activities. Referring to groundwaters, individual major anions and cations (K⁺, Na⁺, Ca²⁺, Mg²⁺, NO₃⁻, SO₄²⁻, Cl⁻) were influenced by various natural and anthropogenic factors whereas Ni, Cr, Cu and Zn were controlled by industrial and agronomic activities. The identification of the sources of contaminants in soil and groundwater environments is a valuable basis for encouraging mitigation strategies preventing further quality degradation.

Influence of red mud on soil microbial communities: Application and comprehensive evaluation of the Biolog EcoPlate approach as a tool in soil microbiological studies.

PubMed

Feigl, Viktória; Ujaczki, Éva; Vaszita, Emese; Molnár, Mónika

2017-10-01

Red mud can be applied as soil ameliorant to acidic, sandy and micronutrient deficient soils. There are still knowledge gaps regarding the effects of red mud on the soil microbial community. The Biolog EcoPlate technique is a promising tool for community level physiological profiling. This study presents a detailed evaluation of Biolog EcoPlate data from two case studies. In experiment "A" red mud from Ajka (Hungary) was mixed into acidic sandy soil in soil microcosms at 5-50 w/w%. In experiement "B" red mud soil mixture was mixed into low quality subsoil in a field experiment at 5-50 w/w%. According to average well color development, substrate average well color development and substrate richness 5-20% red mud increased the microbial activity of the acidic sandy soil over the short term, but the effect did not last for 10months. Shannon diversity index showed that red mud at up to 20% did not change microbial diversity over the short term, but the diversity decreased by the 10th month. 30-50% red mud had deteriorating effect on the soil microflora. 5-20% red mud soil mixture in the low quality subsoil had a long lasting enhancing effect on the microbial community based on all Biolog EcoPlate parameters. However, 50% red mud soil mixture caused a decrease in diversity and substrate richness. With the Biolog EcoPlate we were able to monitor the changes of the microbial community in red mud affected soils and to assess the amount of red mud and red mud soil mixture applicable for soil treatment in these cases. Copyright © 2017 Elsevier B.V. All rights reserved.

Soil fungi colony growth and community dynamics

NASA Astrophysics Data System (ADS)

Falconer, Ruth E.; Kravchenko, Alexandra; Otten, Wilfred

2010-05-01

Fungi are a major player in soil functioning, they contribute to soil structure formation and shaping of plant communities through their role in nutrient cycling, pathogenesis and symbiosis. Theoretical approaches which have emerged over the years and improved considerably our understanding of above ground plant communities are still lacking below ground. A theoretical framework is needed, such that links soil physics, fungal biology and mathematical biology in order to understand fungal community dynamics and diversity in undisturbed soils. Such a framework is essential if we are to understand how environmental change or soil manipulation impacts biodiversity. Different land use and management practices significantly affect soil environmental characteristics crucial for fungal communities by contributing different quantities and qualities of biomass inputs, generating different levels of soil disturbance, influencing soil temperature and moisture regimes, and affecting structure and geometry of soil pore space. Differences in pore structures generated by long-term differences in land use and management are reflected in notable changes in soil physical and hydraulic properties, including soil porosity, hydraulic conductivity and water retention (Brye and Pirani, 2005). Changes in numbers, shapes, and distributions of soil macropores have been often observed (e.g., Pachepsky et al., 1996; Giménez et al., 1997; Udawatta et al., 2008). However, specific implications of these differences in pore structure and geometries for ability of pathogenic as well as non-pathogenic fungi to colonize soil have not yet been addressed. Recent advances in computed tomography and microscopy facilitate detailed examination of the inner pore structures of undisturbed soil samples as well as visualization of fungal mycelia. Such tools together with modelling generate a new level of understanding of the mechanisms governing fungal behaviour at microscopic scales, and for the first time allow us to examine species interactions in a 3D soil environment.

Study of microarthropod communities to assess soil quality in different managed vineyards

NASA Astrophysics Data System (ADS)

Gagnarli, Elena; Vignozzi, Nadia; Valboa, Giuseppe; Bouneb, Mabrouk; Corino, Lorenzo; Goggioli, Donatella; Guidi, Silvia; Lottero, Mariarosa; Tarchi, Franca; Simoni, Sauro

2014-05-01

Land use type influences the abundance and diversity of soil arthropods. The evaluation of the effects of different crop managements on soil quality is commonly requested; it can be pursued by means of the determination of communities' structure of edaphic fauna. The development and application of biological indices may represent an efficient mean to assess soil quality. We evaluated the effect of crop managements (organic and Integrated Pest Management-IPM) in some vineyards in Piedmont (Italy) on soil biota in relation to some physical and chemical characteristics of the soil. The study was performed in eleven sites, including seven organic and four IPM managed vineyards located in the Costigliole d'Asti area. Samplings were carried out during the winter 2011 and the spring 2012. Soil samples were collected using a cylindrical soil core sampler (3cm diameter x 30cm height): each sample was a cylindrical soil core which was equally subdivided to study arthropod communities at different depth ranges. Additional samples were collected and analyzed for the following soil physical and chemical properties: texture (sedigraph method), pH (1:2.5 soil/water), total organic carbon (TOC), total nitrogen (NT) and calcium carbonate (dry combustion by CN analyzer). The extraction of microarthropods was performed using the selector Berlese-Tullgren. All specimens were counted and determined up to the order level. The influence of soil properties and of agronomic practices on the abundance of mesofauna was evaluated by multivariate analysis (MANOVA). The biological soil quality was also defined through the determination of biotic indices such as the qualitative and quantitative QBSar (Quality Biological Soil - arthropods), and biodiversity indices such as species richness and indices of Shannon-Wiener (H') and Simpson (D). Overall, more than four thousands arthropods were collected and the highest abundance was in biological management with about 2:1 ratio (biological vs conventional/IPM management). The mites represented about 50% of the arthropodofauna recorded, collembolans 30%, and 20% other microarthropods (Blattaria, Chilopoda, Coleoptera, Diplopoda, Diplura, Diptera, Hemiptera, Hymenoptera, Isopoda, Homoptera, Pauropoda, Protura, Pseudoscopionida, Psocoptera, Symphyla, Thysanoptera). The mesofauna abundance was affected by the type of management (P=0.015) and soil texture (P=0.029). At the identification level considered, the biological indices calculated showed no substantial differences between different crop managements (H'=1.26, D=0.97 in organic vineyard, H'=1.30, D=0.89 in IPM vineyard). The analysis of microarthropod communities by QBSar, however, showed higher values in organic compared to IPM managed vineyards (QBSar 199 vs 98 in 2011 and 205 vs 188 in 2012, respectively) which are close to figures characteristic of preserved soils.

Productivity of Rice Grown on Arsenic Contaminated Soil under a Changing Climate

NASA Astrophysics Data System (ADS)

Wang, T.; Plaganas, M.; Muehe, E. M.; Fendorf, S. E.

2016-12-01

Rice is the staple food for more than 50% of the global population. In South and Southeast Asia, native soil arsenic coupled with arsenic-laden irrigation water result in paddy soils having arsenic levels that decrease the quality and productivity of rice and thus compromise food security worldwide. However, it remains unknown how climate change will affect the accumulation of arsenic in rice plants, specifically grain, grown in arsenic-bearing paddy soils. We hypothesize that the bioavailability of arsenic in the paddy soil will increase with climate change leading to an even sharper decrease of rice productivity and quality than presently estimated. In order to shed light on this question, we performed greenhouse studies to simulate today's climate condition in Asian paddy soils and compare it to the conditions projected for the year 2100. We investigated climate conditions estimated in the 5th assessment report of the IPCC1, indicating up to a 5°C increase in temperature and doubled atmospheric CO2 concentrations. Under these current and future climate conditions, we examined rice physiology including plant height and biomass, leaf chlorophyll content, grain number and weight as well as contents of accumulated arsenic, and its species in the different rice tissues. We further correlate different geochemical parameters of the soil, including arsenic and other relevant metal dynamics in the soil, to plant response. In sum, our analyses will allow us to better predict the productivity of rice and its grain quality in a future climate condition, and may help to take precautions to avoid a global food crisis, particularly for South and Southeast Asia where rice is a daily staple. 1IPCC - Intergovernmental Panel on Climate Change, Climate Change 2013, The Physical Science Basis.

Metagenomic analysis of soil and freshwater from zoo agricultural area with organic fertilization

PubMed Central

Meneghine, Aylan K.; Nielsen, Shaun; Thomas, Torsten; Carareto Alves, Lucia Maria

2017-01-01

Microbial communities drive biogeochemical cycles in agricultural areas by decomposing organic materials and converting essential nutrients. Organic amendments improve soil quality by increasing the load of essential nutrients and enhancing the productivity. Additionally, fresh water used for irrigation can affect soil quality of agricultural soils, mainly due to the presence of microbial contaminants and pathogens. In this study, we investigated how microbial communities in irrigation water might contribute to the microbial diversity and function of soil. Whole-metagenomic sequencing approaches were used to investigate the taxonomic and the functional profiles of microbial communities present in fresh water used for irrigation, and in soil from a vegetable crop, which received fertilization with organic compost made from animal carcasses. The taxonomic analysis revealed that the most abundant genera were Polynucleobacter (~8% relative abundance) and Bacillus (~10%) in fresh water and soil from the vegetable crop, respectively. Low abundance (0.38%) of cyanobacterial groups were identified. Based on functional gene prediction, denitrification appears to be an important process in the soil community analysed here. Conversely, genes for nitrogen fixation were abundant in freshwater, indicating that the N-fixation plays a crucial role in this particular ecosystem. Moreover, pathogenicity islands, antibiotic resistance and potential virulence related genes were identified in both samples, but no toxigenic genes were detected. This study provides a better understanding of the community structure of an area under strong agricultural activity with regular irrigation and fertilization with an organic compost made from animal carcasses. Additionally, the use of a metagenomic approach to investigate fresh water quality proved to be a relevant method to evaluate its use in an agricultural ecosystem. PMID:29267397

The Profile Quality of Pond In Kendal Regency to Diversification Aquaculture

NASA Astrophysics Data System (ADS)

Ayuniar, Ligar Novi; Hidayat, Jafron Wasiq

2018-02-01

Water quality, particularly coastal areas, is systematically tropogenic. The decline in water quality is caused by industrial waste pollution, soil erosion carried by the river, and the depletion of mangrove areas. The decrease of water quality can affect the fishery cultivation activities that exist in the region. It also affects the quality of the cultivated fish. Fish cultivated in ponds with poor water quality can be harmful to the health of the people who consume the fish. One effort to manage the feasibility of pond waters is by identifying the quality. The purpose of this research is to know the profile of pond water quality and to know the diversity potential of aquaculture. Based on the nature of the problem this research is a field research, while the purpose of this study is descriptive and explanatory research. The method used in this research is research by using survey method. Aquatic profile results are essential to improve the quality and quantity of Fisheries, especially in diversifying fisheries.

Climate-change effects on soils: Accelerated weathering, soil carbon and elemental cycling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qafoku, Nikolla

2015-04-01

Climate change [i.e., high atmospheric carbon dioxide (CO2) concentrations (≥400 ppm); increasing air temperatures (2-4°C or greater); significant and/or abrupt changes in daily, seasonal, and inter-annual temperature; changes in the wet/dry cycles; intensive rainfall and/or heavy storms; extended periods of drought; extreme frost; heat waves and increased fire frequency] is and will significantly affect soil properties and fertility, water resources, food quantity and quality, and environmental quality. Biotic processes that consume atmospheric CO2, and create organic carbon (C) that is either reprocessed to CO2 or stored in soils are the subject of active current investigations, with great concern over themore » influence of climate change. In addition, abiotic C cycling and its influence on the inorganic C pool in soils is a fundamental global process in which acidic atmospheric CO2 participates in the weathering of carbonate and silicate minerals, ultimately delivering bicarbonate and Ca2+ or other cations that precipitate in the form of carbonates in soils or are transported to the rivers, lakes, and oceans. Soil responses to climate change will be complex, and there are many uncertainties and unresolved issues. The objective of the review is to initiate and further stimulate a discussion about some important and challenging aspects of climate-change effects on soils, such as accelerated weathering of soil minerals and resulting C and elemental fluxes in and out of soils, soil/geo-engineering methods used to increase C sequestration in soils, soil organic matter (SOM) protection, transformation and mineralization, and SOM temperature sensitivity. This review reports recent discoveries, identifies key research needs, and highlights opportunities offered by the climate-change effects on soils.« less

Enzyme activities by indicator of quality in organic soil

NASA Astrophysics Data System (ADS)

Raigon Jiménez, Mo; Fita, Ana Delores; Rodriguez Burruezo, Adrián

2016-04-01

The analytical determination of biochemical parameters, as soil enzyme activities and those related to the microbial biomass is growing importance by biological indicator in soil science studies. The metabolic activity in soil is responsible of important processes such as mineralization and humification of organic matter. These biological reactions will affect other key processes involved with elements like carbon, nitrogen and phosphorus , and all transformations related in soil microbial biomass. The determination of biochemical parameters is useful in studies carried out on organic soil where microbial processes that are key to their conservation can be analyzed through parameters of the metabolic activity of these soils. The main objective of this work is to apply analytical methodologies of enzyme activities in soil collections of different physicochemical characteristics. There have been selective sampling of natural soils, organic farming soils, conventional farming soils and urban soils. The soils have been properly identified conserved at 4 ° C until analysis. The enzyme activities determinations have been: catalase, urease, cellulase, dehydrogenase and alkaline phosphatase, which bring together a representative group of biological transformations that occur in the soil environment. The results indicate that for natural and agronomic soil collections, the values of the enzymatic activities are within the ranges established for forestry and agricultural soils. Organic soils are generally higher level of enzymatic, regardless activity of the enzyme involved. Soil near an urban area, levels of activities have been significantly reduced. The vegetation cover applied to organic soils, results in greater enzymatic activity. So the quality of these soils, defined as the ability to maintain their biological productivity is increased with the use of cover crops, whether or spontaneous species. The practice of cover based on legumes could be used as an ideal choice for the recovery of degraded soils, because these soils have the highest levels of enzymatic activities.

Soil Eukaryotic Microorganism Succession as Affected by Continuous Cropping of Peanut - Pathogenic and Beneficial Fungi were Selected

PubMed Central

Chen, Mingna; Li, Xiao; Yang, Qingli; Chi, Xiaoyuan; Pan, Lijuan; Chen, Na; Yang, Zhen; Wang, Tong; Wang, Mian; Yu, Shanlin

2012-01-01

Peanut is an important oil crop worldwide and shows considerable adaptability but growth and yield are negatively affected by continuous cropping. Soil micro-organisms are efficient bio-indicators of soil quality and plant health and are critical to the sustainability of soil-based ecosystem function and to successful plant growth. In this study, 18S rRNA gene clone library analyses were employed to study the succession progress of soil eukaryotic micro-organisms under continuous peanut cultivation. Eight libraries were constructed for peanut over three continuous cropping cycles and its representative growth stages. Cluster analyses indicated that soil micro-eukaryotic assemblages obtained from the same peanut cropping cycle were similar, regardless of growth period. Six eukaryotic groups were found and fungi predominated in all libraries. The fungal populations showed significant dynamic change and overall diversity increased over time under continuous peanut cropping. The abundance and/or diversity of clones affiliated with Eurotiales, Hypocreales, Glomerales, Orbiliales, Mucorales and Tremellales showed an increasing trend with continuous cropping but clones affiliated with Agaricales, Cantharellales, Pezizales and Pyxidiophorales decreased in abundance and/or diversity over time. The current data, along with data from previous studies, demonstrated that the soil microbial community was affected by continuous cropping, in particular, the pathogenic and beneficial fungi that were positively selected over time, which is commonplace in agro-ecosystems. The trend towards an increase in fungal pathogens and simplification of the beneficial fungal community could be important factors contributing to the decline in peanut growth and yield over many years of continuous cropping. PMID:22808226

Assessment of Soil Environmental Quality in Huangguoshu Waterfalls Scenic Area

NASA Astrophysics Data System (ADS)

Luo, Rongbin; Feng, Kaiyu; Gu, Bo; Xu, Chengcheng

2018-03-01

This paper concentrates on five major heavy metal pollutants as soil environmental quality evaluation factors, respectively Lead (Pb), Cadmium (Cd), Mercury (Hg), Arsenic (As), Chromium (Cr), based on the National Soil Environmental Quality Standards (GB15618 - 1995), we used single factor index evaluation model of soil environmental quality and comprehensive index evaluation model to analyze surface soil environmental quality in the Huangguoshu Waterfalls scenic area. Based on surface soil analysis, our results showed that the individual contamination index, Pb, Hg, As and Cr in the Huangguoshu Waterfalls scenic area met class I according to requirements of National Soil Environmental Quality Standards, which indicated that Pb, Hg, As and Cr were not main heavy metal pollutants in this area, but the individual contamination index of Cd in soil was seriously exceeded National Soil Environmental Quality Standards’ requirement. Soil environmental quality in Shitouzhai, Luoshitan, Langgong Hongyan Power Plant have exceeded the requirement of National Soil Environmental Quality Standards “0.7< Pc≤ 1.0” (Alert Level), these soils had been slightly polluted; the classification of soil environmental quality assessment in Longgong downstream area was above “Alert Level”, it indicated that soil in this area was not polluted. Above all, relevant measures for soil remediation are put forward.

40 CFR 60.1115 - What is a siting analysis?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 6 2010-07-01 2010-07-01 false What is a siting analysis? 60.1115 Section 60.1115 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... unit affects ambient air quality, visibility, soils, vegetation, and other relevant factors. The...

The resistance of the active microbiome as a fundamental compartment of soil quality in the face of climate change

NASA Astrophysics Data System (ADS)

Bastida, Felipe; Andrés, Manuela; Torres, Irene; García, Carlos; Ruiz Navarro, Antonio; Moreno, Francisco R.; López Serrano, Francisco R.

2017-04-01

Arid and semiarid ecosystems will be severely affected by drought derived from climate change. Forest management can promote the adaptations of plant and microbial communities to drought. For instance, thinning reduces competition for resources through a decrease in tree density and the promotion of plant survival. The resistance of soil microbial communities must be strongly related to the soil quality. However, in order to evaluate these properties, the active (and not only the total) microbial community should be carefully assessed. Here, we studied the functional and phylogenetic responses of the microbial community to six years of drought induced by rainfall exclusion and how thinning shapes its resistance to drought, in a semiarid ecosystem dominated by Pinus halepensis Mill. A multiOMIC approach was applied to reveal novel strategies against drought. The diversity and the composition of the total and active soil microbial communities were evaluated by 16S rRNA gene (bacteria) and ITS (fungal) sequencing, and by metaproteomics. The microbial biomass was analyzed by phospholipid fatty acids (PLFAs), and the microbially-mediated ecosystem multifunctionality was studied by the evaluation of enzyme activities related to C, N, and P dynamics. The microbial biomass and ecosystem multifunctionality decreased in plots subjected to drought, but this decrease was greater in unthinned plots. The diversity of the total bacterial and fungal communities were resistant to drought but were shaped by seasonal dynamics. However, the active community was more sensitive to drought and related to multifunctionality. Thinning in plots without drought increased the active diversity while the total diversity was not affected. Thinning promoted the resistance of multifunctionality to drought by changes in the active microbiome. Protein-based phylogeny was a better predictor of the impacts of drought and the adaptations of microbial communities. We highlight that the resistance of the microbial community and the active microbial community are ecological concepts strongly related to the concept of soil quality in the face of climate change.

Environmental indicators for sustainable production of algal biofuels

DOE PAGES

Efroymson, Rebecca A.; Dale, Virginia H.

2014-10-01

For analyzing sustainability of algal biofuels, we identify 16 environmental indicators that fall into six categories: soil quality, water quality and quantity, air quality, greenhouse gas emissions, biodiversity, and productivity. Indicators are selected to be practical, widely applicable, predictable in response, anticipatory of future changes, independent of scale, and responsive to management. Major differences between algae and terrestrial plant feedstocks, as well as their supply chains for biofuel, are highlighted, for they influence the choice of appropriate sustainability indicators. Algae strain selection characteristics do not generally affect which indicators are selected. The use of water instead of soil as themore » growth medium for algae determines the higher priority of water- over soil-related indicators. The proposed set of environmental indicators provides an initial checklist for measures of biofuel sustainability but may need to be modified for particular contexts depending on data availability, goals of the stakeholders, and financial constraints. Ultimately, use of these indicators entails defining sustainability goals and targets in relation to stakeholder values in a particular context and can lead to improved management practices.« less

[Relationships between soil and rocky desertification in typical karst mountain area based on redundancy analysis].

PubMed

Long, Jian; Liao, Hong-Kai; Li, Juan; Chen, Cai-Yun

2012-06-01

Redundancy analysis (RDA) was employed to reveal the relationships between soil and rocky desertification through vegetation investigation and analysis of soil samples collected in typical karst mountain area of southwest Guizhou Province. The results showed that except TP, TK and ACa, all other variables including SOC, TN, MBC, ROC, DOC, available nutrients and basal respiration showed significant downward trends during the rocky desertification process. RDA results showed significant correlations between different types of desertification and soil variables, described as non-degraded > potential desertification > light desertification > moderate desertification > severe desertification. Moreover, RDA showed that using SOC, TN, AN, and BD as soil indicators, 74.4% of the variance information on soil and rocky desertification could be explained. Furthermore, the results of correlation analysis showed that soil variables were significantly affected by surface vegetation. Considering the ecological function of the aboveground vegetation and the soil quality, Zanthoxylum would be a good choice for restoration of local vegetation in karst mountain area.

The past, present, and future of soils and human health studies

NASA Astrophysics Data System (ADS)

Brevik, E. C.; Sauer, T. J.

2015-01-01

The idea that human health is tied to the soil is not a new one. As far back as circa 1400 BC the Bible depicts Moses as understanding that fertile soil was essential to the well-being of his people. In 400 BC the Greek philosopher Hippocrates provided a list of things that should be considered in a proper medical evaluation, including the properties of the local ground. By the late 1700s and early 1800s, American farmers had recognized that soil properties had some connection to human health. In the modern world, we recognize that soils have a distinct influence on human health. We recognize that soils influence (1) food availability and quality (food security), (2) human contact with various chemicals, and (3) human contact with various pathogens. Soils and human health studies include investigations into nutrient supply through the food chain and routes of exposure to chemicals and pathogens. However, making strong, scientific connections between soils and human health can be difficult. There are multiple variables to consider in the soil environment, meaning traditional scientific studies that seek to isolate and manipulate a single variable often do not provide meaningful data. The complete study of soils and human health also involves many different specialties such as soil scientists, toxicologists, medical professionals, anthropologists, etc. These groups do not traditionally work together on research projects, and do not always effectively communicate with one another. Climate change and how it will affect the soil environment/ecosystem going into the future is another variable affecting the relationship between soils and health. Future successes in soils and human health research will require effectively addressing difficult issues such as these.

Overview of different aspects of climate change effects on soils

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qafoku, Nikolla P.

2014-08-01

Climate change [i.e., high atmospheric carbon dioxide (CO 2) concentrations (≥400 ppm); increasing air temperatures (2-4°C or greater); significant and/or abrupt changes in daily, seasonal, and inter-annual temperature; changes in the wet/dry cycles; intensive rainfall and/or heavy storms; extended periods of drought; extreme frost; heat waves and increased fire frequency] is and will significantly affect soil properties and fertility, water resources, food quantity and quality, and environmental quality. Biotic processes that consume atmospheric CO 2 and create organic carbon (C) that is either reprocessed to CO 2 or stored in soils, are the subject of active current investigations with greatmore » concern over the influence of climate change. In addition, abiotic C cycling and its influence on the inorganic C pool in soils is a fundamental global process in which acidic atmospheric CO 2 participates in the weathering of carbonate and silicate minerals, ultimately delivering bicarbonate and Ca 2+ or other cations that precipitate in the form of carbonates in soils or are transported to the rivers, lakes, and oceans. Soil responses to climate change will be complex, and there are many uncertainties and unresolved issues. The objective of the review is to initiate and further stimulate a discussion about some important and challenging aspects of climate-change effects on soils, such as accelerated weathering of soil minerals and resulting C and elemental fluxes in and out of soils, soil/geo-engineering methods used to increase C sequestration in soils, soil organic matter (SOM) protection, transformation and mineralization, and SOM temperature sensitivity. This review reports recent discoveries and identifies key research needs required to understand the effects of climate change on soils.« less

Landscape scale assessment of soil and water salinization processes in agricultural coastal area.

NASA Astrophysics Data System (ADS)

Elen Bless, Aplena; Follain, Stéphane; Coiln, François; Crabit, Armand

2017-04-01

Soil salinization is among main land degradation process around the globe. It reduces soil quality, disturbs soil function, and has harmful impacts on plant growth that would threaten agricultural sustainability, particularly in coastal areas where mostly susceptible on land degradation because of pressure from anthropogenic activities and at the same time need to preserve soil quality for supporting food production. In this presentation, we present a landscape scale analysis aiming to assess salinization process affecting wine production. This study was carried out at Serignan estuary delta in South of France (Languadoc Roussillon Region, 43˚ 28'N and 3˚ 31'E). It is a sedimentary basin near coastline of Mediterranean Sea. Field survey was design to characterize both space and time variability of soil and water salinity through water electrical conductivity (ECw) and soil 1/5 electrical conductivity (EC1/5). For water measurements, Orb River and groundwater salinity (piezometers) were determined and for soil 1737 samples were randomly collected from different soil depths (20, 50, 80, and 120 cm) between year 2012 and 2016 and measured. In order to connect with agricultural practices observations and interviews with farmers were conducted. We found that some areas combining specific criteria presents higher electrical conductivity: positions with lower elevation (a.s.l), Cambisols (Calcaric) / Fluvisols soil type (WRB) and dominated clay textures. These observations combined with geochemical determination and spatial analysis confirm our first hypothesis of sea salt intrusion as the main driven factor of soil salinity in this region. In this context, identification of salinization process, fine determination of pedological specificities and fine understanding of agricultural practices allowed us to proposed adaptation strategies to restore soil production function. Please fill in your abstract text. Key Words: Salinity, Coastal Agriculture, Landscape, Soil, Water

Particulate Organic Matter Affects Soil Nitrogen Mineralization under Two Crop Rotation Systems

PubMed Central

Bu, Rongyan; Lu, Jianwei; Ren, Tao; Liu, Bo; Li, Xiaokun; Cong, Rihuan

2015-01-01

Changes in the quantity and/or quality of soil labile organic matter between and after different types of cultivation system could play a dominant role in soil nitrogen (N) mineralization. The quantity and quality of particulate organic matter (POM) and potentially mineralizable-N (PMN) contents were measured in soils from 16 paired rice-rapeseed (RR)/cotton-rapeseed (CR) rotations sites in Hubei province, central China. Then four paired soils encompassing low (10th percentile), intermediate (25th and 75th percentiles), and high (90th percentile) levels of soil PMN were selected to further study the effects of POM on soil N mineralization by quantifying the net N mineralization in original soils and soils from which POM was removed. Both soil POM carbon (POM-C) and N (POM-N) contents were 45.8% and 55.8% higher under the RR rotation compared to the CR rotation, respectively. The PMN contents were highly correlated with the POM contents. The PMN and microbial biomass N (MBN) contents concurrently and significantly decreased when POM was removed. The reduction rate of PMN was positively correlated with changes in MBN after the removal of POM. The reduction rates of PMN and MBN after POM removal are lower under RR rotations (38.0% and 16.3%, respectively) than CR rotations (45.6% and 19.5%, respectively). Furthermore, infrared spectroscopy indicated that compounds with low-bioavailability accumulated (e.g., aromatic recalcitrant materials) in the soil POM fraction under the RR rotation but not under the CR rotation. The results of the present study demonstrated that POM plays a vital role in soil N mineralization under different rotation systems. The discrepancy between POM content and composition resulting from different crop rotation systems caused differences in N mineralization in soils. PMID:26647157

Particulate Organic Matter Affects Soil Nitrogen Mineralization under Two Crop Rotation Systems.

PubMed

Bu, Rongyan; Lu, Jianwei; Ren, Tao; Liu, Bo; Li, Xiaokun; Cong, Rihuan

2015-01-01

Changes in the quantity and/or quality of soil labile organic matter between and after different types of cultivation system could play a dominant role in soil nitrogen (N) mineralization. The quantity and quality of particulate organic matter (POM) and potentially mineralizable-N (PMN) contents were measured in soils from 16 paired rice-rapeseed (RR)/cotton-rapeseed (CR) rotations sites in Hubei province, central China. Then four paired soils encompassing low (10th percentile), intermediate (25th and 75th percentiles), and high (90th percentile) levels of soil PMN were selected to further study the effects of POM on soil N mineralization by quantifying the net N mineralization in original soils and soils from which POM was removed. Both soil POM carbon (POM-C) and N (POM-N) contents were 45.8% and 55.8% higher under the RR rotation compared to the CR rotation, respectively. The PMN contents were highly correlated with the POM contents. The PMN and microbial biomass N (MBN) contents concurrently and significantly decreased when POM was removed. The reduction rate of PMN was positively correlated with changes in MBN after the removal of POM. The reduction rates of PMN and MBN after POM removal are lower under RR rotations (38.0% and 16.3%, respectively) than CR rotations (45.6% and 19.5%, respectively). Furthermore, infrared spectroscopy indicated that compounds with low-bioavailability accumulated (e.g., aromatic recalcitrant materials) in the soil POM fraction under the RR rotation but not under the CR rotation. The results of the present study demonstrated that POM plays a vital role in soil N mineralization under different rotation systems. The discrepancy between POM content and composition resulting from different crop rotation systems caused differences in N mineralization in soils.

Influence of Precipitation Regime on Microbial Decomposition Patterns in Semi-Arid Ecosystems

NASA Astrophysics Data System (ADS)

Feris, K. P.; Jilek, C.; Huber, D. P.; Reinhardt, K.; deGraaff, M.; Lohse, K.; Germino, M.

2011-12-01

In water-limited semi-arid sagebrush steppe ecosystems predicted changes in climate may manifest as a shift from historically winter/snow-dominated precipitation regimes to one dominated by spring rains. In these ecosystems soil microorganisms play a vital role in linking the effects of water availability and plant productivity to biogeochemical cycling. Patterns of soil microbial catalyzed organic matter decomposition patters (i.e. patterns of extracellular enzyme activity (EEA)) are thought to depend upon the quantity and quality of soil organic matter (SOM), pH, and mean annual precipitation (Sinsabaugh, 2008), and less on the timing and magnitude of precipitation. However, sagebrush-steppe plant communities respond strongly to changes in the timing and magnitude of precipitation, and preliminary findings by our group suggest that corresponding changes in SOM quantity, quality, N-cycle dynamics, and soil structure are occurring. Therefore, we hypothesized: 1) Shifts in the timing and magnitude of precipitation would indirectly affect soil microbial decomposition patterns via responses in the plant community structure; and 2) Changes in precipitation patterns can directly affect soil microbial community structure and function, in effect uncoupling the interaction between plant community structure and soil community structure. We tested our hypotheses by determining the influence of experimentally manipulated timing and magnitude of precipitation on soil microbial EEA using standard flourometric assays in soils sampled under plant canopies and plant interspaces. We assessed this response in a mature (18 + years) ecohydrologic field experiment in eastern Idaho that annually imitates three possible post climatic-shift precipitation regimes (Ambient (AMB): no additional precipitation, ~200mm annually; Summer (SUMM): 200mm provisioned at 50mm bi-weekly starting in June; and Fall/Spring (F/S): 200mm provisioned over 1-2 weeks in October or April) (n=3). Within plant interspaces Beta glucosaminide activity increased by 18% in treatments receiving additional F/S precipitation, whereas alpha glucopyranoside activity was lower in the F/S and SUMM plots. Conversely, underplant canopies alpha glucopyranoside activity increased by 15% in the SUMM and F/S precipitation treatments. Across treatments and sampling types (i.e. plant canopy vs. interspace), cellobioside activity levels are consistently elevated in response to additional precipitation compared to those of the control plots. When coupled with recent preliminary findings by our group regarding changes in plant and microbial community structure and SOM, C-storage, and soil structural responses, these preliminary findings suggest that 1) microbial community structure and function respond both directly and indirectly to changes in climate, and 2) thus provide a mechanism for changes in plant community structure to feed-forward to affect soil carbon decomposition patterns and ultimately soil carbon storage potential.

Use of compost to restore a contaminated site in Southern Italy: preliminary study to assess compost efficiency in remediating a heavily polluted soil in Taranto city.

NASA Astrophysics Data System (ADS)

Ancona, Valeria; Campanale, Claudia; Calabrese, Angelantonio; Vito Felice, Uricchio; Simona, Regano

2014-05-01

Soil pollution is one of the most soil relevant threats recognized in the world. Contamination affects soil quality and soil capacity to react against several land degradation processes (erosion, organic depletion, desertification, etc.). The identification of opportune strategies to hinder pollution is a fundamental requirement to restore soil quality. In particular, large attentions have got the techniques, which promote the decontamination, and at the same time, improve fertility allowing a new use of a soil restored. In this work we present a preliminary study to assess the use of compost (an organic fertilizer produced through a process of transformation and controlled stabilization of selected organic waste at the source) in remediating a heavily polluted soil in southern Italy. The study site is located in Taranto city (Apulia Region) and is contaminated predominantly by heavy metals and lightly by organic toxic compounds such us polychlorinated biphenyls (PCBs). An exhaustive chemical characterization has been carried out on soil samples and then, a treatment with compost was applied on the study site. Successively, two data acquisition campaigns have been realized (after 4 and 7 months by compost treatment, respectively). Soil chemical analyses of texture, electrical conductivity, pH, organic carbon content, total nitrogen, available phosphorous, carbonate and water content have been carried out to investigate soil properties. In the polluted site chemical analyses of characterization showed low content of nutrients (nitrogen and phosphorous) and high level of carbonate. Heavy metals screenings, carried out through ICP-MS equipment, evidenced a massive contamination by Be, Se, Sn, Pb, Cr, Zn, while GC-MS investigations revealed a lower pollution by PCBs. The results of the monitoring campaigns showed a consistent reduction of the heavy metals concentrations: a higher decrease is observed after 7 months by compost treatment. At the same time, a considerable increase of organic carbon, nitrogen and phosphorus is also registered. The overall results suggest that the use of compost contributed to improve soil physico-chemical properties and promote a relevant decrease of pollution suggesting that a process of soil quality restoration is performing.

40 CFR 60.1125 - What must I include in my siting analysis?

Code of Federal Regulations, 2014 CFR

2014-07-01

... waste combustion unit affects four areas: (1) Ambient air quality. (2) Visibility. (3) Soils. (4) Vegetation. (b) Include an analysis of alternatives for controlling air pollution that minimize potential... analysis? 60.1125 Section 60.1125 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR...

40 CFR 60.1125 - What must I include in my siting analysis?

Code of Federal Regulations, 2011 CFR

2011-07-01

... waste combustion unit affects four areas: (1) Ambient air quality. (2) Visibility. (3) Soils. (4) Vegetation. (b) Include an analysis of alternatives for controlling air pollution that minimize potential... analysis? 60.1125 Section 60.1125 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR...

40 CFR 60.1125 - What must I include in my siting analysis?

Code of Federal Regulations, 2013 CFR

2013-07-01

... waste combustion unit affects four areas: (1) Ambient air quality. (2) Visibility. (3) Soils. (4) Vegetation. (b) Include an analysis of alternatives for controlling air pollution that minimize potential... analysis? 60.1125 Section 60.1125 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR...

40 CFR 60.1125 - What must I include in my siting analysis?

Code of Federal Regulations, 2012 CFR

2012-07-01

... waste combustion unit affects four areas: (1) Ambient air quality. (2) Visibility. (3) Soils. (4) Vegetation. (b) Include an analysis of alternatives for controlling air pollution that minimize potential... analysis? 60.1125 Section 60.1125 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR...

Responses of soil and water chemistry to mountain pine beetle induced tree mortality in Grand County, Colorado, USA

USGS Publications Warehouse

Clow, David W.; Rhoades, Charles; Briggs, Jenny S.; Caldwell, Megan K.; Lewis, William M.

2011-01-01

Pine forest in northern Colorado and southern Wyoming, USA, are experiencing the most severe mountain pine beetle epidemic in recorded history, and possible degradation of drinking-water quality is a major concern. The objective of this study was to investigate possible changes in soil and water chemistry in Grand County, Colorado in response to the epidemic, and to identify major controlling influences on stream-water nutrients and C in areas affected by the mountain pine beetle. Soil moisture and soil N increased in soils beneath trees killed by the mountain pine beetle, reflecting reduced evapotranspiration and litter accumulation and decay. No significant changes in stream-water NO3-">NO3- or dissolved organic C were observed; however, total N and total P increased, possibly due to litter breakdown or increased productivity related to warming air temperatures. Multiple-regression analyses indicated that % of basin affected by mountain pine beetles had minimal influence on stream-water NO3-">NO3- and dissolved organic C; instead, other basin characteristics, such as percent of the basin classified as forest, were much more important.

Using (137)Cs to quantify the redistribution of soil organic carbon and total N affected by intensive soil erosion in the headwaters of the Yangtze River, China.

PubMed

Guoxiao, Wei; Yibo, Wang; Yan Lin, Wang

2008-12-01

Characteristics of soil organic carbon (SOC) and total nitrogen (total N) are important for determining the overall quality of soils. Studies on spatial and temporal variation in SOC and total N are of great importance because of global environmental concerns. Soil erosion is one of the major processes affecting the redistribution of SOC and total N in the test fields. To characterize the distribution and dynamics of SOC and N in the intensively eroded soil of the headwaters of the Yangtze River, China, we measured profiles of soil organic C, total N stocks, and (137)Cs in a control plot and a treatment plot. The amounts of SOC, (137)Cs of sampling soil profiles increased in the following order, lower>middle>upper portions on the control plot, and the amounts of total N of sampling soil profile increase in the following order: upper>middle>lower on the control plot. Intensive soil erosion resulted in a significant decrease of SOC amounts by 34.9%, 28.3% and 52.6% for 0-30cm soil layer at upper, middle and lower portions and (137)Cs inventory decreased by 68%, 11% and 85% at upper, middle and lower portions, respectively. On the treatment plot total N decreased by 50.2% and 14.6% at the upper and middle portions and increased by 48.9% at the lower portion. Coefficients of variation (CVs) of SOC decreased by 31%, 37% and 30% in the upper, middle and lower slope portions, respectively. Similar to the variational trend of SOC, CVs of (137)Cs decreased by 19.2%, 0.5% and 36.5%; and total N decreased by 45.7%, 65.1% and 19% in the upper, middle and lower slope portions, respectively. The results showed that (137)Cs, SOC and total N moved on the sloping land almost in the same physical mechanism during the soil erosion procedure, indicating that fallout of (137)Cs could be used directly for quantifying dynamic SOC and total N redistribution as the soil was affected by intensive soil erosion.

Metal Distribution in Urban Agricultural Soils in the Inland Empire, California

NASA Astrophysics Data System (ADS)

Marin, C. C. E.

2015-12-01

Urban environments exhibit unique biogeochemistry due to the presence of a myriad of anthropogenic sources of contaminants. One potential route through which humans have been exposed to metal contaminants is the ingestion of food produced on urban soils. The Inland Empire is a metropolitan located in semi-arid region of Southern California with greater than 4 million residents, where the growing population is demonstrating an increase in citizen participation in contributing to expanding local food systems. In response to the demand for locally grown produce, the Inland Empire is undergoing rapid land use change, where large tracts of land on the periphery of cities, including Riverside, are being converted or set aside for urban agriculture, though the quality of the soil for food production is unknown. At the same time, smaller gardens and farms are growing in number within the more densely populated areas. Assessing the quality of urban soil currently used for food production in this region can aid in projecting how land use change will affect the quality of crops produced as urban agriculture continues to expand in arid regions. Soil samples were taken from a variety of land use types, including areas currently producing crops and areas set aside for future large scale food production. Samples were collected at the surface (0-2 cm) and below till depth (20-22 cm). These soils were analyzed for total carbon including organic and inorganic carbon fractions, total nitrogen, bulk metal and trace metal concentrations (including As, Mn, Cr, Pb, Cd, Zn, and Cu). To approximate the mobility of the trace elements under various conditions, extraction tests were also performed, including EPA Pb bioavailability analysis. Finally, we utilize statistical tools and spatial analysis to illustrate the relationship between previous land use, current land use, and soil quality for urban crop production.

Effects of changes in soil properties derived from land levelling on grape quality and yield in the Priorat (Spain)

NASA Astrophysics Data System (ADS)

Concepción Ramos, Maria

2017-04-01

Soil characteristics together with topography and climate influence on the suitability of the environment for grapevine growing and wine production grapevine growth and fruit qualities. Thus, changes in soil properties derived from field works and agricultural activities may influence grape production and quality. This work focuses on the effects of land terracing on soil properties, and the changes in grape quality and production. The study was conducted in the Priorat region, where old vineyards planted in steep slopes have been adapted for the labour mechanization with the construction of terraces. Changes in soil properties, such as organic matter, infiltration, water retention capacity were analysed in both old and transformed vineyards. Grape yield, pH, acidity and the likely alcohol content were evaluated in a sample of 80 plots planted with Grenache and Carignan. The soil surface alterations produced by the terrace construction affected some hydrological properties, such as texture and bulk density, and they also gave rise to lower soil organic matter content (up to 40%), lower available water capacity (up to 25%)and hydraulic (up to 55%). For the evaluated varieties, there were differences in yield between both new and old vineyards: 2.18 vs 0.68 kg/vine for Carignan and 2.34 vs 1.64 kg/vine for Grenache. For Carignan, pH was on average lower in the new than in the old vineyards (3.46 vs. and 3.51) and higher differences were observed in the acidity (5.29 vs. 4.22). Similarly for Grenache, pH values were 3.3 vs 3.24 and acidity 5.18 vs 4.69. Smaller differences were found in the likely alcohol content although it was always higher in the old vineyards (14.5 and 14.9 for Carignan and Grenache, respectively) than in the new vineyards (13.7 and 14.5 for Carignan and Grenache, respectively).

How Fencing Affects the Soil Quality and Plant Biomass in the Grassland of the Loess Plateau

PubMed Central

Liu, Yang; Xiao, Li; Huang, Yimei

2017-01-01

Overgrazing is a severe problem in several regions in Northwestern China and has caused serious land degradation. Secondary natural succession plays an important role in the accumulation of soil carbon and nitrogen contents. Estimating the effects of grazing exclusion on soil quality and plant diversity will improve our understanding of the succession process after overgrazing and promote judicious management of degraded pastures. This experiment was designed to measure soil properties and plant diversity following an age chronosequence of grasslands (ages ranged from one year, 12 years, 20 years, and 30 years) in Northwestern China. The results showed that continuous fencing resulted in a considerable increase in plant coverage, plant biomass (above- and below-ground biomass), and plant diversity, which can directly or indirectly improve the accumulation of soil organic carbon and total nitrogen content. The plant coverage and the above- and below-ground biomass linearly increased along the succession time, whereas soil organic C and N contents showed a significant decline in the first 12 years and, subsequently, a significant increase. The increased plant biomass caused an increase in soil organic carbon and soil total nitrogen. These results suggested that soil restoration and plant cover were an incongruous process. Generally, soil restoration is a slow process and falls behind vegetation recovery after grazing exclusion. Although the accumulation of soil C and N stocks needed a long term, vegetation restoration was a considerable option for the degraded grassland due to the significant increase of plant biomass, diversity, and soil C and N stocks. Therefore, fencing with natural succession should be considered in the design of future degraded pastures. PMID:28946681

Impact of treated wastewater on growth, respiration and hydraulic conductivity of citrus root systems in light and heavy soils.

PubMed

Paudel, Indira; Cohen, Shabtai; Shaviv, Avi; Bar-Tal, Asher; Bernstein, Nirit; Heuer, Bruria; Ephrath, Jhonathan

2016-06-01

Roots interact with soil properties and irrigation water quality leading to changes in root growth, structure and function. We studied these interactions in an orchard and in lysimeters with clay and sandy loam soils. Minirhizotron imaging and manual sampling showed that root growth was three times lower in the clay relative to sandy loam soil. Treated wastewater (TWW) led to a large reduction in root growth with clay (45-55%) but not with sandy loam soil (<20%). Treated wastewater increased salt uptake, membrane leakage and proline content, and decreased root viability, carbohydrate content and osmotic potentials in the fine roots, especially in clay. These results provide evidence that TWW challenges and damages the root system. The phenology and physiology of root orders were studied in lysimeters. Soil type influenced diameter, specific root area, tissue density and cortex area similarly in all root orders, while TWW influenced these only in clay soil. Respiration rates were similar in both soils, and root hydraulic conductivity was severely reduced in clay soil. Treated wastewater increased respiration rate and reduced hydraulic conductivity of all root orders in clay but only of the lower root orders in sandy loam soil. Loss of hydraulic conductivity increased with root order in clay and clay irrigated with TWW. Respiration and hydraulic properties of all root orders were significantly affected by sodium-amended TWW in sandy loam soil. These changes in root order morphology, anatomy, physiology and hydraulic properties indicate rapid and major modifications of root systems in response to differences in soil type and water quality. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

How Fencing Affects the Soil Quality and Plant Biomass in the Grassland of the Loess Plateau.

PubMed

Zeng, Quanchao; Liu, Yang; Xiao, Li; Huang, Yimei

2017-09-25

Overgrazing is a severe problem in several regions in Northwestern China and has caused serious land degradation. Secondary natural succession plays an important role in the accumulation of soil carbon and nitrogen contents. Estimating the effects of grazing exclusion on soil quality and plant diversity will improve our understanding of the succession process after overgrazing and promote judicious management of degraded pastures. This experiment was designed to measure soil properties and plant diversity following an age chronosequence of grasslands (ages ranged from one year, 12 years, 20 years, and 30 years) in Northwestern China. The results showed that continuous fencing resulted in a considerable increase in plant coverage, plant biomass (above- and below-ground biomass), and plant diversity, which can directly or indirectly improve the accumulation of soil organic carbon and total nitrogen content. The plant coverage and the above- and below-ground biomass linearly increased along the succession time, whereas soil organic C and N contents showed a significant decline in the first 12 years and, subsequently, a significant increase. The increased plant biomass caused an increase in soil organic carbon and soil total nitrogen. These results suggested that soil restoration and plant cover were an incongruous process. Generally, soil restoration is a slow process and falls behind vegetation recovery after grazing exclusion. Although the accumulation of soil C and N stocks needed a long term, vegetation restoration was a considerable option for the degraded grassland due to the significant increase of plant biomass, diversity, and soil C and N stocks. Therefore, fencing with natural succession should be considered in the design of future degraded pastures.

The influence of long-term copper contaminated agricultural soil at different pH levels on microbial communities and springtail transcriptional regulation.

PubMed

de Boer, Tjalf E; Taş, Neslihan; Braster, Martin; Temminghoff, Erwin J M; Röling, Wilfred F M; Roelofs, Dick

2012-01-03

Copper has long been applied for agricultural practises. Like other metals, copper is highly persistent in the environment and biologically active long after its use has ceased. Here we present a unique study on the long-term effects (27 years) of copper and pH on soil microbial communities and on the springtail Folsomia candida an important representative of the soil macrofauna, in an experiment with a full factorial, random block design. Bacterial communities were mostly affected by pH. These effects were prominent in Acidobacteria, while Actinobacteria and Gammaroteobacteria communities were affected by original and bioavailable copper. Reproduction and survival of the collembolan F. candida was not affected by the studied copper concentrations. However, the transcriptomic responses to copper reflected a mechanism of copper transport and detoxification, while pH exerted effects on nucleotide and protein metabolism and (acute) inflammatory response. We conclude that microbial community structure reflected the history of copper contamination, while gene expression analysis of F. candida is associated with the current level of bioavailable copper. The study is a first step in the development of a molecular strategy aiming at a more comprehensive assessment of various aspects of soil quality and ecotoxicology.

High-resolution soil moisture mapping in Afghanistan

NASA Astrophysics Data System (ADS)

Hendrickx, Jan M. H.; Harrison, J. Bruce J.; Borchers, Brian; Kelley, Julie R.; Howington, Stacy; Ballard, Jerry

2011-06-01

Soil moisture conditions have an impact upon virtually all aspects of Army activities and are increasingly affecting its systems and operations. Soil moisture conditions affect operational mobility, detection of landmines and unexploded ordinance, natural material penetration/excavation, military engineering activities, blowing dust and sand, watershed responses, and flooding. This study further explores a method for high-resolution (2.7 m) soil moisture mapping using remote satellite optical imagery that is readily available from Landsat and QuickBird. The soil moisture estimations are needed for the evaluation of IED sensors using the Countermine Simulation Testbed in regions where access is difficult or impossible. The method has been tested in Helmand Province, Afghanistan, using a Landsat7 image and a QuickBird image of April 23 and 24, 2009, respectively. In previous work it was found that Landsat soil moisture can be predicted from the visual and near infra-red Landsat bands1-4. Since QuickBird bands 1-4 are almost identical to Landsat bands 1- 4, a Landsat soil moisture map can be downscaled using QuickBird bands 1-4. However, using this global approach for downscaling from Landsat to QuickBird scale yielded a small number of pixels with erroneous soil moisture values. Therefore, the objective of this study is to examine how the quality of the downscaled soil moisture maps can be improved by using a data stratification approach for the development of downscaling regression equations for each landscape class. It was found that stratification results in a reliable downscaled soil moisture map with a spatial resolution of 2.7 m.

Environmental aspects of produced-water salt releases in onshore and coastal petroleum-producing areas of the conterminous U.S. - a bibliography

USGS Publications Warehouse

Otton, James K.

2006-01-01

Environmental effects associated with the production of oil and gas have been reported since the first oil wells were drilled in the Appalachian Basin in Pennsylvania and Kentucky in the early to mid-1800s. The most significant of these effects are the degradation of soils, ground water, surface water, and ecosystems they support by releases of suspended and dissolved hydrocarbons and co-produced saline water. Produced water salts are less likely than hydrocarbons to be adsorbed by mineral phases in the soil and sediment and are not subject to degradation by biologic processes. Sodium is a major dissolved constituent in most produced waters and it causes substantial degradation of soils through altering of clays and soil textures and subsequent erosion. Produced water salts seem to have the most wide-ranging effects on soils, water quality, and ecosystems. Trace elements, including boron, lithium, bromine, fluorine, and radium, also occur in elevated concentrations in some produced waters. Many trace elements are phytotoxic and are adsorbed and may remain in soils after the saline water has been flushed away. Radium-bearing scale and sludge found in oilfield equipment and discarded on soils pose additional hazards to human health and ecosystems. This bibliography includes studies from across the oil- and natural-gas-producing areas of the conterminous United States that were published in the last 80 yrs. The studies describe the effects of produced water salts on soils, water quality, and ecosystems. Also included are reports that describe (1) the inorganic chemistry of produced waters included in studies of formation waters for various purposes, (2) other sources of salt affecting water quality that may be mistaken for produced water effects, (3) geochemical and geophysical techniques that allow discrimination of salt sources, (4) remediation technologies designed to repair damage caused to soils and ground water by produced water salts, and (5) contamination by naturally occurring radioactive materials (NORM)at oilfield sites.

Comparison of commercial DNA extraction kits for isolation and purification of bacterial and eukaryotic DNA from PAH-contaminated soils.

PubMed

Mahmoudi, Nagissa; Slater, Greg F; Fulthorpe, Roberta R

2011-08-01

Molecular characterization of the microbial populations of soils and sediments contaminated with polycyclic aromatic hydrocarbons (PAHs) is often a first step in assessing intrinsic biodegradation potential. However, soils are problematic for molecular analysis owing to the presence of organic matter, such as humic acids. Furthermore, the presence of contaminants, such as PAHs, can cause further challenges to DNA extraction, quantification, and amplification. The goal of our study was to compare the effectiveness of four commercial soil DNA extraction kits (UltraClean Soil DNA Isolation kit, PowerSoil DNA Isolation kit, PowerMax Soil DNA Isolation kit, and FastDNA SPIN kit) to extract pure, high-quality bacterial and eukaryotic DNA from PAH-contaminated soils. Six different contaminated soils were used to determine if there were any biases among the kits due to soil properties or level of contamination. Extracted DNA was used as a template for bacterial 16S rDNA and eukaryotic 18S rDNA amplifications, and PCR products were subsequently analyzed using denaturing gel gradient electrophoresis (DGGE). We found that the FastDNA SPIN kit provided significantly higher DNA yields for all soils; however, it also resulted in the highest levels of humic acid contamination. Soil texture and organic carbon content of the soil did not affect the DNA yield of any kit. Moreover, a liquid-liquid extraction of the DNA extracts found no residual PAHs, indicating that all kits were effective at removing contaminants in the extraction process. Although the PowerSoil DNA Isolation kit gave relatively low DNA yields, it provided the highest quality DNA based on successful amplification of both bacterial and eukaryotic DNA for all six soils. DGGE fingerprints among the kits were dramatically different for both bacterial and eukaryotic DNA. The PowerSoil DNA Isolation kit revealed multiple bands for each soil and provided the most consistent DGGE profiles among replicates for both bacterial and eukaryotic DNA.

Data analysis protocol for using resistivity array as an early-warning wastewater pond leak detector

USDA-ARS?s Scientific Manuscript database

Typically, holding ponds are used to control runoff from concentrated animal feeding operations. The integrity of these holding ponds has come under increased scrutiny since subsurface leakage has the potential to affect soil and groundwater quality. Traditionally, ponds are monitored by installin...

Groundwater and stream response times to fertility management changes in pastures

USDA-ARS?s Scientific Manuscript database

To assess the effectiveness of best-management practices (BMPs), measurements need to be made to determine how the implementation of BMPs affect water quality and soil loss from the areas receiving the practices. For large watersheds (multiple square miles in area) this is a difficult, expensive, a...

Fertilizer placement to maximize nitrogen use by fescue

USDA-ARS?s Scientific Manuscript database

The method of fertilizer nitrogen(N) application can affect N uptake in tall fescue and therefore its yield and quality. Subsurface-banding (knife) of fertilizer maximizes fescue N uptake in the poorly-drained clay–pan soils of southeastern Kansas. This study was conducted to determine if knifed N r...

Can surface-applied zeolite reduce ammonia losses from feedyard manure? A laboratory study

USDA-ARS?s Scientific Manuscript database

Ammonia emission from beef cattle feedyard manure results in losses of nitrogen (N), which may negatively affect air, soil, and water quality. The magnitude and rate of ammonia volatilization from feedyards partially depends on the amount of urinary urea excreted and dissociation of ionic ammonium ...

Application of the WEPS and SWEEP models to non-agricultural disturbed lands

USDA-ARS?s Scientific Manuscript database

Wind erosion not only affects agricultural productivity but also soil, air, and water quality. Dust and specifically particulate matter = 10 µm (PM-10) has adverse effects on respiratory health and also reduces visibility along roadways, resulting in auto accidents. The Wind Erosion Prediction Syste...

Effects of Soil Salinity on the Expression of Bt Toxin (Cry1Ac) and the Control Efficiency of Helicoverpa armigera in Field-Grown Transgenic Bt Cotton.

PubMed

Luo, Jun-Yu; Zhang, Shuai; Peng, Jun; Zhu, Xiang-Zhen; Lv, Li-Min; Wang, Chun-Yi; Li, Chun-Hua; Zhou, Zhi-Guo; Cui, Jin-Jie

2017-01-01

An increasing area of transgenic Bacillus thuringiensis (Bt) cotton is being planted in saline-alkaline soil in China. The Bt protein level in transgenic cotton plants and its control efficiency can be affected by abiotic stress, including high temperature, water deficiency and other factors. However, how soil salinity affects the expression of Bt protein, thus influencing the control efficiency of Bt cotton against the cotton bollworm (CBW) Helicoverpa armigera (Hübner) in the field, is poorly understood. Our objective in the present study was to investigate the effects of soil salinity on the expression of Bt toxin (Cry1Ac) and the control efficiency of Helicoverpa armigera in field-grown transgenic Bt cotton using three natural saline levels (1.15 dS m-1 [low soil-salinity], 6.00 dS m-1 [medium soil-salinity] and 11.46 dS m-1 [high soil-salinity]). We found that the Bt protein content in the transgenic Bt cotton leaves and the insecticidal activity of Bt cotton against CBW decreased with the increasing soil salinity in laboratory experiments during the growing season. The Bt protein content of Bt cotton leaves in the laboratory were negatively correlated with the salinity level. The CBW populations were highest on the Bt cotton grown in medium-salinity soil instead of the high-salinity soil in field conditions. A possible mechanism may be that the relatively high-salinity soil changed the plant nutritional quality or other plant defensive traits. The results from this study may help to identify more appropriate practices to control CBW in Bt cotton fields with different soil salinity levels.

Effects of Soil Salinity on the Expression of Bt Toxin (Cry1Ac) and the Control Efficiency of Helicoverpa armigera in Field-Grown Transgenic Bt Cotton

PubMed Central

Luo, Jun-Yu; Zhang, Shuai; Peng, Jun; Zhu, Xiang-Zhen; Lv, Li-Min; Wang, Chun-Yi; Li, Chun-Hua; Zhou, Zhi-Guo; Cui, Jin-Jie

2017-01-01

An increasing area of transgenic Bacillus thuringiensis (Bt) cotton is being planted in saline-alkaline soil in China. The Bt protein level in transgenic cotton plants and its control efficiency can be affected by abiotic stress, including high temperature, water deficiency and other factors. However, how soil salinity affects the expression of Bt protein, thus influencing the control efficiency of Bt cotton against the cotton bollworm (CBW) Helicoverpa armigera (Hübner) in the field, is poorly understood. Our objective in the present study was to investigate the effects of soil salinity on the expression of Bt toxin (Cry1Ac) and the control efficiency of Helicoverpa armigera in field-grown transgenic Bt cotton using three natural saline levels (1.15 dS m-1 [low soil-salinity], 6.00 dS m-1 [medium soil-salinity] and 11.46 dS m-1 [high soil-salinity]). We found that the Bt protein content in the transgenic Bt cotton leaves and the insecticidal activity of Bt cotton against CBW decreased with the increasing soil salinity in laboratory experiments during the growing season. The Bt protein content of Bt cotton leaves in the laboratory were negatively correlated with the salinity level. The CBW populations were highest on the Bt cotton grown in medium-salinity soil instead of the high-salinity soil in field conditions. A possible mechanism may be that the relatively high-salinity soil changed the plant nutritional quality or other plant defensive traits. The results from this study may help to identify more appropriate practices to control CBW in Bt cotton fields with different soil salinity levels. PMID:28099508

Use of geophysical methods in man-made hazard management strategies. Case study from Ploiesti city, Romania

NASA Astrophysics Data System (ADS)

Chitea, F.; Anghelache, M. A.; Ioane, D.

2010-05-01

Identification of damages/changes that are affecting the underground water quality due to the effect of anthropogenic activities is often done after environmental problems have become evident, water potability being strongly affected. In this paper we will discuss the necessity of implementing non-invasive and non-destructive investigation tools in different parts of the management plan for urban areas affected or with high risk of being affected by man-made hazards. Geophysical investigations represent nowadays a useful tool in environmental problems that affect soil and underground water in urban areas, as useful information can be obtained regarding the following aspects: - detection of affected areas, especially when the effect or hazard sources are not visible at the surface - zonation of the area (severely affected zone or less affected) - investigation of the area (details on affected surface and affected soil depth) - location of "hidden" sources (illegal waste dump sites, petroleum transport or transfer pipes, etc) - estimation of soil and underground damages by monitoring petrophysical markers - risk evaluation (estimations on the direction and speed of environmental problems development, estimations of amplifying negative effects) - recovery from the man-made hazard of a certain area (monitoring information can give information about natural attenuation of the environmental problems or efficacy of resilience program) - preparedness for man-made hazards (prediction). Functionality of the above mentioned plans of geophysical applicability in identifying and characterizing the effect of anthropogenic hazards which affect soil and underground water quality has been tested in Ploiesti city, Romania. In this urban area, as well as in surrounding villages, water potability is severely affected because of the oil-products contamination caused by the refinery facilities developed in the area. Oil-contamination is a major problem environmental problem, due to the fact that affected area is continuously expanding as a consequence of contaminant transport by the underground water. Hydrogeologically the research area is located in the alluvium of one of the main hydrostructures of Romania, which holds important water resources. Preliminary investigations made in the Ploiesti city area, has shown the high vulnerability of the aquifer to pollution and it was detected a highly contaminated area. By detailed investigations made using geophysical investigations in the test-zone, it was possible the detection of the presence of the particular type of pollutants and a map with area zonation has been produced. Appliance of geophysical investigations in environmental strategies concerning underground water pollution should be added to the ones obtained by direct investigations for risk evaluation and remediation strategies in cases of man made hazards. Acknowledgements: The research was performed with financial support from MENER (project nr. 725/ 2006) and CNCSIS-UEFISCU (project nr. 244/2007)

Soil Quality Indicator: a new concept

NASA Astrophysics Data System (ADS)

Barão, Lúcia; Basch, Gottlieb

2017-04-01

During the last century, cultivated soils have been intensively exploited for food and feed production. This exploitation has compromised the soils' natural functions and many of the soil-mediated ecosystems services, including its production potential for agriculture. Also, soils became increasingly vulnerable and less resilient to a wide range of threats. To overcome this situation, new and better management practices are needed to prevent soil from degradation. However, to adopt the best management practices in a specific location, it is necessary to evaluate the soil quality status first. Different soil quality indicators have been suggested over the last decades in order to evaluate the soil status, and those are often based on the performance of soil chemical, physical and biological properties. However, the direct link between these properties and the associated soil functions or soil vulnerability to threats appears more difficult to be established. This present work is part of the iSQAPER project- Interactive Soil Quality Assessment in Europe and China for Agricultural Productivity and Environmental Resilience, where new soil quality concepts are explored to provide better information regarding the effects of the most promising agricultural management practices on soil quality. We have developed a new conceptual soil quality indicator which determines the soil quality status, regarding its vulnerability towards different threats. First, different indicators were specifically developed for each of the eight threats considered - Erosion, SOM decline, Poor Structure, Poor water holding capacity, Compaction, N-Leaching, Soil-borne pests and diseases and Salinization. As an example for the case of Erosion, the RUSLE equation for the estimate of the soil annual loss was used. Secondly, a reference classification was established for each indicator to integrate all possible results into a Good, Intermediate or Bad classification. Finally, all indicators were combined to return a single evaluation of the soil status, using different techniques that are dependent on the final use of the soil quality indicator. Some of the advantages of this new concept include the evaluation of soil quality based on its vulnerability to threats, together with the evaluation of soil properties in a given context while also suggesting soil management practices that are directly capable to mitigate soil vulnerability towards specific threats. Keywords: Soil Quality, Agriculture, Sustainability, Soil threats

Relationships among plants, soils and microbial communities along a hydrological gradient in the New Jersey Pinelands, USA

PubMed Central

Yu, Shen; Ehrenfeld, Joan G.

2010-01-01

Background and Aims Understanding the role of different components of hydrology in structuring wetland communities is not well developed. A sequence of adjacent wetlands located on a catenary sequence of soils and receiving the same sources and qualities of water is used to examine specifically the role of water-table median position and variability in affecting plant and microbial community composition and soil properties. Methods Two replicates of three types of wetland found adjacent to each other along a hydrological gradient in the New Jersey Pinelands (USA) were studied. Plant-community and water-table data were obtained within a 100-m2 plot in each community (pine swamp, maple swamp and Atlantic-white-cedar swamp). Monthly soil samples from each plot were analysed for soil moisture, organic matter, extractable nitrogen fractions, N mineralization rate and microbial community composition. Multivariate ordination methods were used to compare patterns among sites within and between data sets. Key Results The maple and pine wetlands were more similar to each other in plant community composition, soil properties and microbial community composition than either was to the cedar swamps. However, maple and pine wetlands differed from each other in water-table descriptors as much as they differed from the cedar swamps. All microbial communities were dominated by Gram-positive bacteria despite hydrologic differences among the sites. Water-table variability was as important as water-table level in affecting microbial communities. Conclusions Water tables affect wetland communities through both median level and variability. Differentiation of both plant and microbial communities are not simple transforms of differences in water-table position, even when other hydrologic factors are kept constant. Rather, soil genesis, a result of both water-table position and geologic history, appears to be the main factor affecting plant and microbial community similarities. PMID:19643908

The effects of grazing intensity on soil processes in a Mediterranean protected area.

PubMed

Panayiotou, Evaggelia; Dimou, Maria; Monokrousos, Nikolaos

2017-08-08

We investigated the temporal and among-site differentiation of soil functionality properties in fields under different grazing intensities (heavy and light) and compared them to those found in their adjacent hedgerows, consisting either of wooden shrubs (Rubus canescens) or of high trees (Populus sp.), during the cold and humid seasons of the year. We hypothesized that greater intensity of grazing would result in higher degradation of the soil system. The grazing factor had a significant effect on soil organic C and N, microbial biomass C, microbial biomass N, microbial activity, and β-glucosidase, while acid phosphatase and urease activity were not found to differ significantly among the management systems. The intensity of grazing affected mostly the chemical properties of soil (organic C and N) and altered significantly the composition of the soil microbial community, as lower C:N ratio of the microbial biomass indicates the dominance of bacteria over fungi in the heavily grazed fields. All estimated biological variables presented higher values in the humid period, although the pattern of differentiation was similar at both sampling times, revealing that site-specific variations were more pronounced than the time-specific ones. Our results indicate that not all C, N, and P dynamics were equally affected by grazing. Management plans applied to pastures, in order to improve soil quality properties and accelerate passive reforestation, should aim at the improvement of soil parameters related primarily to C and secondly to N cycle.

Plant effects on soil denitrification - a review of potential mechanisms

NASA Astrophysics Data System (ADS)

Malique, Francois; Butterbach-Bahl, Klaus; Dannenmann, Michael

2017-04-01

Denitrification is a microbial process occurring in soils, both producing and consuming the potent greenhouse gas nitrous oxide (NO), competing for nitrate with plants and hydrological leaching pathways, removing nutrients and reactive nitrogen from the biosphere, and closing the global nitrogen cycle. Despite its obvious importance, denitrification remained among the least well quantified biogeochemical processes in soils. This is due to enormous methodological difficulties involved in the direct quantification of soil microbial denitrification rates (mainly with regard to the terminal product N2) and the denitrification nitrogen gas product ratios (NO:N2O:N2), Plants may affect denitrification through a myriad of mechanisms such as e.g., competition for nitrate and water, through oxygen consumption, by regulating litter quality and changing soil pH, and via the exudation of labile carbon or secondary plant compounds involved in shaping the rhizospheric microbial community. However, plant effects on denitrification so far hardly were quantified so that the actual extent of plant control on denitrification is largely unknown. Here, we summarize the current knowledge on mechanisms how plants can affect denitrification rates and N gas product ratios in soils at temporal scales from hours to days and years. We review earlier research to quantify plant effects on denitrification as well as critically discuss the limited methods currently available to quantify plant-soil-denitrifier interactions. Finally, we provide pointers to use plants as tools to manage denitrification, e.g. to improve N use efficiency in agricultural ecosystems and to minimize soil nitrous oxide emissions.

How will climate change affect vine behaviour in different soils?

NASA Astrophysics Data System (ADS)

Leibar, Urtzi; Aizpurua, Ana; Morales, Fermin; Pascual, Inmaculada; Unamunzaga, Olatz

2014-05-01

Various agricultural sectors are sensitive to projected climate change. In this sense, the strong link between climate and grapevine phenology and berry quality suggests a relevant impact. Within the concept of terroir, climate is a factor that influences ripening of a specific variety and resulting wine style. Furthermore, the effect of soil on grape potential is complex, because the soil acts on grapevine water and nutrient supply, and influences root zone temperature. The aim of this work was to evaluate the effect of climate change (increased CO2, higher temperature and lower relative humidity), soil texture and irrigation on the physiology, yield and berry quality of grapevine (Vitis vinifera L.) cv. Tempranillo. A greenhouse experiment was carried out with potted, own-rooted fruit-bearing cuttings. Three factors were studied: a) climate change (700 μmol CO2 mol-1 air, 28/18°C and 45/65% day/night relative humidity) vs. current conditions (375 μmol CO2 mol-1 air, 24/14ºC and 33/53% day/night relative humidity), b) soil texture (9, 18 and 36% soil clay content) and c) irrigation; well-irrigated (20-35% of soil water content) vs. water deficit (60% of the water applied to the irrigated plants). Berries were harvested at ripeness (21-23 ºBrix). Climate change shortened the time between veraison and full maturity up to 9 days and reduced the number of berries per bunch. Grapes grown under climate change conditions had higher pH and lower acidity (due to malic and tartaric acids), anthocyanins content and colour intensity. Water-deficit delayed ripening up to 10 days and reduced final leaf area and root weight. Berries from water stressed plants had an increased skin/pulp ratio and pH, and lower acidity (malic acid) and polyphenol content. Regarding soil texture, plants grown in the soil with lower clay content increased root fresh weight and had higher total anthocyanins content. There were no interactions between factors. In conclusion, both climate change and water-deficit had a clear influence on the grape phenological development and composition, whilst soil affected root configuration and anthocyanins concentration. Effects of climate change and water availability on different soil conditions should be considered to take full advantage or mitigate the consequences of the future climate conditions.

Predicting soil quality indices with near infrared analysis in a wildfire chronosequence.

PubMed

Cécillon, Lauric; Cassagne, Nathalie; Czarnes, Sonia; Gros, Raphaël; Vennetier, Michel; Brun, Jean-Jacques

2009-01-15

We investigated the power of near infrared (NIR) analysis for the quantitative assessment of soil quality in a wildfire chronosequence. The effect of wildfire disturbance and soil engineering activity of earthworms on soil organic matter quality was first assessed with principal component analysis of NIR spectra. Three soil quality indices were further calculated using an adaptation of the method proposed by Velasquez et al. [Velasquez, E., Lavelle, P., Andrade, M. GISQ, a multifunctional indicator of soil quality. Soil Biol Biochem 2007; 39: 3066-3080.], each one addressing an ecosystem service provided by soils: organic matter storage, nutrient supply and biological activity. Partial least squares regression models were developed to test the predicting ability of NIR analysis for these soil quality indices. All models reached coefficients of determination above 0.90 and ratios of performance to deviation above 2.8. This finding provides new opportunities for the monitoring of soil quality, using NIR scanning of soil samples.

Primary factors affecting water quality and quantity in four watersheds in Eastern Puerto Rico

USGS Publications Warehouse

Murphy, Sheila F.; Stallard, Robert F.

2009-01-01

As part of the U.S. Geological Survey (USGS) Water, Energy, and Biogeochemical Budgets (WEBB) program, four small watersheds in eastern Puerto Rico were monitored to identify and evaluate the effects of geology, landcover, atmospheric deposition, and other factors on stream water quality and quantity. Two catchments are located on coarse-grained granitic plutonic rocks, which weather to quartz- and clay-rich, sandy soils, and two are located on fine-grained volcanic rocks and volcaniclastic sediments, which weather to quartz-poor, fine-grained soils. These differing soil materials result in different hydrologic regimes. Soils on the granitic rocks have greater permeability than those developed on the volcaniclastic rocks, allowing more water infiltration and potentially greater landslide erosion rates. For each bedrock type, one catchment was covered with mature rainforest, and the other catchment was affected by agricultural practices typical of eastern Puerto Rico. These practices led to the erosion of much of the original surface soil in the agricultural watersheds, which introduced large quantities of sediment to stream channels. The agricultural watersheds are undergoing natural reforestation, like much of Puerto Rico. Eastern Puerto Rico receives large atmospheric inputs of marine salts, pollutants from the Northern Hemisphere, and Saharan Desert dust. Marine salts contribute over 80 percent of the ionic charge in precipitation, with peak inputs in January. Intense storms, mostly hurricanes, are associated with exceptionally high chloride concentrations in stream waters. Temperate pollution contributes nitrate, ammonia, and sulfate, with maximum inputs during northern cold fronts in January, April, and May. Pollution inputs have increased through time. Desert dust peaks in June and July, during times of maximum dust transport from the Saharan Desert across the Atlantic Ocean.

An invisible soil acidification: Critical role of soil carbonate and its impact on heavy metal bioavailability

PubMed Central

Wang, Cheng; Li, Wei; Yang, Zhongfang; Chen, Yang; Shao, Wenjing; Ji, Junfeng

2015-01-01

It is well known that carbonates inhibit heavy metals transferring from soil to plants, yet the mechanism is poorly understood. Based on the Yangtze River delta area, we investigated bioaccumulation of Ni and Cd in winter wheat as affected by the presence of carbonates in soil. This study aimed to determine the mechanism through which soil carbonates restrict transport and plant uptake of heavy metals in the wheat cropping system. The results indicate that soil carbonates critically influenced heavy metal transfer from soil to plants and presented a tipping point. Wheat grains harvested from carbonates-depleted (due to severe leaching) soils showed Ni and Cd concentrations 2–3 times higher than those of the wheat grains from carbonates-containing soils. Correspondingly, the incidence of Ni or Cd contamination in the wheat grain samples increased by about three times. With the carbonate concentration >1% in soil, uptake and bioaccumulation of Ni and Cd by winter wheat was independent with the soil pH and carbonate content. The findings suggest that soil carbonates play a critical role in heavy metal transfer from soil to plants, implying that monitoring soil carbonate may be necessary in addition to soil pH for the evaluating soil quality and food safety. PMID:26227091

Evaluation of soil quality indicators in paddy soils under different crop rotation systems

NASA Astrophysics Data System (ADS)

Nadimi-Goki, Mandana; Bini, Claudio; Haefele, Stephan; Abooei, Monireh

2013-04-01

Evaluation of soil quality indicators in paddy soils under different crop rotation systems Soil quality, by definition, reflects the capacity to sustain plant and animal productivity, maintain or enhance water and air quality, and promote plant and animal health. Soil quality assessment is an essential issue in soil management for agriculture and natural resource protection. This study was conducted to detect the effects of four crop rotation systems (rice-rice-rice, soya-rice-rice, fallow-rice and pea-soya-rice) on soil quality indicators (soil moisture, porosity, bulk density, water-filled pore space, pH, extractable P, CEC, OC, OM, microbial respiration, active carbon) in paddy soils of Verona area, Northern Italy. Four adjacent plots which managed almost similarly, over five years were selected. Surface soil samples were collected from each four rotation systems in four times, during growing season. Each soil sample was a composite of sub-samples taken from 3 points within 350 m2 of agricultural land. A total of 48 samples were air-dried and passed through 2mm sieve, for some chemical, biological, and physical measurements. Statistical analysis was done using SPSS. Statistical results revealed that frequency distribution of most data was normal. The lowest CV% was related to pH. Analysis of variance (ANOVA) and comparison test showed that there are significant differences in soil quality indicators among crop rotation systems and sampling times. Results of multivariable regression analysis revealed that soil respiration had positively correlation coefficient with soil organic matter, soil moisture and cation exchange capacity. Overall results indicated that the rice rotation with legumes such as bean and soybean improved soil quality over a long time in comparison to rice-fallow rotation, and this is reflected in rice yield. Keywords: Soil quality, Crop Rotation System, Paddy Soils, Italy

Improvements to measuring water flux in the vadose zone.

PubMed

Masarik, Kevin C; Norman, John M; Brye, Kristofor R; Baker, John M

2004-01-01

Evaluating the impact of land use practices on ground water quality has been difficult because few techniques are capable of monitoring the quality and quantity of soil water flow below the root zone without disturbing the soil profile and affecting natural flow processes. A recently introduced method, known as equilibrium tension lysimetry, was a major improvement but it was not a true equilibrium since it still required manual intervention to maintain proper lysimeter suction. We addressed this issue by developing an automated equilibrium tension lysimeter (AETL) system that continuously matches lysimeter tension to soil-water matric potential of the surrounding soil. The soil-water matric potential of the bulk soil is measured with a heat-dissipation sensor, and a small DC pump is used to apply suction to a lysimeter. The improved automated approach reported here was tested in the field for a 12-mo period. Powered by a small 12-V rechargeable battery, the AETLs were able to continuously match lysimeter suction to soil-water matric potential for 2-wk periods with minimal human attention, along with the added benefit of collecting continuous soil-water matric potential data. We also demonstrated, in the laboratory, methods for continuous measurement of water depth in the AETL, a capability that quantifies drainage on a 10-min interval, making it a true water-flux meter. Equilibrium tension lysimeters have already been demonstrated to be a reliable method of measuring drainage flux, and the further improvements have created a more effective device for studying water drainage and chemical leaching through the soil matrix.

Aggregate stability as an indicator of soil erodibility and soil physical quality: review and perspectives

NASA Astrophysics Data System (ADS)

Le Bissonnais, Yves; Chenu, Claire; Darboux, Frédéric; Duval, Odile; Legout, Cédric; Leguédois, Sophie; Gumiere, Silvio

2010-05-01

Aggregate breakdown due to water and rain action may cause surface crusting, slumping, a reduction of infiltration and interrill erosion. Aggregate stability determines the capacity of aggregates to resist the effects of water and rainfall. In this paper, we evaluated and reviewed the relevance of an aggregate stability measurement to characterize soil physical properties as well as to analyse the processes involved in these properties. Stability measurement assesses the sensitivity of soil aggregates to various basic disaggregation mechanisms such as slaking, differential swelling, dispersion and mechanical breakdown. It has been showed that aggregate size distributions of structural stability tests matched the size distributions of eroded aggregates under rainfall simulations and that erosion amount was well predicted using aggregate stability indexes. It means stability tests could be used to estimate both the erodibility and the size fractions that are available for crust formation and erosion processes. Several studies showed that organic matter was one of the main soil properties affecting soil stability. However, it has also been showed that aggregate stability of a given soil could vary within a year or between years. The factors controlling such changes have still to be specified. Aggregate stability appears therefore as a complex property, depending both on permanent soil characteristics and on dynamic factors such as the crusting stage, the climate and the biological activity. Despite, and may be, because of this complexity, aggregate stability seems an integrative and powerful indicator of soil physical quality. Future research efforts should look at the causes of short-term changes of structural stability, in order to fully understand all its aspects.

Organic amendments derived from a pharmaceutical by-product: benefits and risks

NASA Astrophysics Data System (ADS)

Gigliotti, Giovanni; Cucina, Mirko; Zadra, Claudia; Pezzolla, Daniela; Sordi, Simone; Carla Marcotullio, Maria; Curini, Massimo

2015-04-01

The application of organic amendments to soils, such as sewage sludge, anaerobic digestate and compost is considered a tool for improving soil fertility and enhancing C stocks. The addition of these different organic materials allows a good supply of nutrients for plants but also contributes to C sequestration, affects the microbial activity and the transformation of soil organic matter (SOM). Moreover, the addition of organic amendment has gained importance as a source of CO2 emissions and then as a cause of the "Global Warming". Therefore, it is important to investigate the factors controlling the SOM mineralization in order to improve the soil C sequestration and decreasing at the same time CO2 emissions. Moreover, the quality of organic matter added to the soil will play an important role in these dynamics. Based on these considerations, the aim of the present work was to investigate the effect of the application to an arable soil of different organic materials derived from a pharmaceutical by-product which results from the fermentative biomass after the separation of the lipopolypeptidic antibiotic produced. A microcosm soil experiment was carried out using three different materials: a sewage sludge derived from the stabilization process of the by-product, a digestate obtained from the anaerobic treatment of the by-product and a compost produced by the aerobic treatment of the same digestate. To achieve this aim, the short-term variations of CO2 emissions, enzymatic soil activities (Dehydrogenase total activity and Fluoresceine diacetate hydrolysis), SOM quantity and quality were studied. In addition, process-related residues of antibiotic and decanoic acid (a precursor added during the fermentation) were analyzed on the organic materials to assess their possible presence. Through these analyses it was possible to state that the application to the soil of sewage sludge and anaerobic digestate may have a strong influence on the short-term variations of the parameters evaluated, particularly on enzymatic soil activities and on CO2 emissions. Whereas, results obtained from compost amended soils showed that its addition to the soil affects lower the enzymatic soil activities and CO2 emissions than the other materials. Determinations of antibiotic and decanoic acid residues showed that only small traces of them were recognizable in the sewage sludge and in the anaerobic digestate. Compost showed concentrations of these compounds lower than the method sensibility and then, based on these results, further analysis on the amended soil were considered negligible.

Preliminary analytical results for ash and burned soils from the October 2007 southern California wildfires

USGS Publications Warehouse

Plumlee, Geoffrey S.; Martin, Deborah A.; Hoefen, Todd; Kokaly, Raymond F.; Hageman, Philip; Eckberg, Alison; Meeker, Gregory P.; Adams, Monique; Anthony, Michael; Lamothe, Paul J.

2007-01-01

The U.S. Geological Survey (USGS) collected ash and burned soils from about 28 sites in southern California wildfire areas (Harris, Witch, Ammo, Santiago, Canyon and Grass Valley) from Nov. 2 through 9, 2007 (table 1). USGS researchers are applying a wide variety of analytical methods to these samples, with the goal of helping identify characteristics of the ash and soils from wildland and suburban burned areas that may be of concern for their potential to adversely affect water quality, human health, endangered species, and debris-flow or flooding hazards. These studies are part of the Southern California Multi-Hazards Demonstration Project, and preliminary findings are presented here.

Impacts of Land use and Cover Change on Soil Hydraulic Properties, Rondonia, Brazil

NASA Astrophysics Data System (ADS)

Schultz, K. J.; McGlynn, B. L.; Elsenbeer, H.

2004-05-01

There is a great deal of concern in the scientific community and the popular media about the global impacts of tropical rainforest deforestation. Soil quality does not receive that same media coverage but is greatly affected by deforestation and is a major concern in the tropics, especially in areas undergoing rapid land use and land cover change. Deforestation can lead to changes in the hydrologic regime, loss of topsoil, increased sediment and nutrient loads in waterways, and decreased soil fertility. These impacts are often related to a soil's infiltration capacity and hydraulic conductivity (Ksat). Our research site, Rancho Grande, Rondonia, Brazil, lies in the heart of the most rapid tropical rainforest deforestation in the world. Two watersheds of similar size, comparable topographic relief, and same soil type, were tested for differences in hydraulic conductivity. The two watersheds are differentiated by land use and land cover; one in a primary forest and the other in an actively grazed pasture. We measured infiltration capacity at 13 locations in the primary forest watershed and at 24 locations in the actively grazed pasture. Approximately 150 measurements of Ksat were made at regular depth intervals in both watersheds. Our research focuses on assessing the impact of land use and land cover change (primary rainforest to pasture/grazing) on soil infiltration capacity and subsurface saturated hydraulic conductivity. Statistically significant differences in infiltration capacity and hydraulic conductivity were detected between the pasture and forest sites at depths of 0, 12.5, and 20 cm. Differences between the two sites at depths of 50 and 90cm were not significant. These results demonstrate that the affect of land cover and land use change on soil hydraulic conductivity was confined to shallower depths in the soil profile. Coupled with ongoing watershed runoff studies at Rancho Grande, this research will help clarify how land cover change affects soil hydraulic properties and resulting runoff dynamics.

Identification of regional soil quality factors and indicators: a case study on an alluvial plain (central Turkey)

NASA Astrophysics Data System (ADS)

Şeker, Cevdet; Hüseyin Özaytekin, Hasan; Negiş, Hamza; Gümüş, İlknur; Dedeoğlu, Mert; Atmaca, Emel; Karaca, Ümmühan

2017-05-01

Sustainable agriculture largely depends on soil quality. The evaluation of agricultural soil quality is essential for economic success and environmental stability in rapidly developing regions. In this context, a wide variety of methods using vastly different indicators are currently used to evaluate soil quality. This study was conducted in one of the most important irrigated agriculture areas of Konya in central Anatolia, Turkey, to analyze the soil quality indicators of Çumra County in combination with an indicator selection method, with the minimum data set using a total of 38 soil parameters. We therefore determined a minimum data set with principle component analysis to assess soil quality in the study area and soil quality was evaluated on the basis of a scoring function. From the broad range of soil properties analyzed, the following parameters were chosen: field capacity, bulk density, aggregate stability, and permanent wilting point (from physical soil properties); electrical conductivity, Mn, total nitrogen, available phosphorus, pH, and NO3-N (from chemical soil properties); and urease enzyme activity, root health value, organic carbon, respiration, and potentially mineralized nitrogen (from biological properties). According to the results, the chosen properties were found as the most sensitive indicators of soil quality and they can be used as indicators for evaluating and monitoring soil quality at a regional scale.

Effects of long-term poultry litter application on phosphorus soil chemistry and runoff water quality.

PubMed

Reiter, Mark S; Daniel, Tommy C; DeLaune, Paul B; Sharpley, Andrew N; Lory, John A

2013-11-01

Continuous application of poultry litter (PL) significantly changes many soil properties, including soil test P (STP); Al, Fe, and Ca concentrations; and pH, which can affect the potential for P transport in surface runoff water. We conducted rainfall simulations on three historically acidic silt loam soils in Arkansas, Missouri, and Virginia to establish if long-term PL applications would affect soil inorganic P fractions and the resulting dissolved reactive P (DRP) in runoff water. Soil samples (0-5 cm depth) were taken to find sites ranging in Mehlich-3 STP from 20 to 1154 mg P kg. Simulated rainfall events were conducted on 3-m plots at 6.7 cm h, and runoff was collected for 30 min. Correlation between Mehlich-3 and runoff DRP indicated a linear relationship to 833 mg Mehlich-3 P kg. As Mehlich-3 STP increased, a concomitant increase in soil pH and Ca occurred on all soils. Soil P fractionation demonstrated that, as Mehlich-3 STP generally increased above 450 mg P kg (from high to very high), the easily soluble and loosely bound P fractions decreased by 3 to 10%. Water-insoluble complexes of P bound to Al and Ca were the main drivers in the reduction of DRP in runoff, accounting for up to 43 and 38% of total P, respectively. Basing runoff DRP concentration projections solely on Mehlich-3 STP may overestimate runoff P losses from soils receiving long-term PL applications due to dissolution of water-insoluble Ca-P compounds. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Moisture drives surface decomposition in thawing tundra

NASA Astrophysics Data System (ADS)

Hicks Pries, Caitlin E.; Schuur, E. A. G.; Vogel, Jason G.; Natali, Susan M.

2013-07-01

Permafrost thaw can affect decomposition rates by changing environmental conditions and litter quality. As permafrost thaws, soils warm and thermokarst (ground subsidence) features form, causing some areas to become wetter while other areas become drier. We used a common substrate to measure how permafrost thaw affects decomposition rates in the surface soil in a natural permafrost thaw gradient and a warming experiment in Healy, Alaska. Permafrost thaw also changes plant community composition. We decomposed 12 plant litters in a common garden to test how changing plant litter inputs would affect decomposition. We combined species' tissue-specific decomposition rates with species and tissue-level estimates of aboveground net primary productivity to calculate community-weighted decomposition constants at both the thaw gradient and warming experiment. Moisture, specifically growing season precipitation and water table depth, was the most significant driver of decomposition. At the gradient, an increase in growing season precipitation from 200 to 300 mm increased mass loss of the common substrate by 100%. At the warming experiment, a decrease in the depth to the water table from 30 to 15 cm increased mass loss by 100%. At the gradient, community-weighted decomposition was 21% faster in extensive than in minimal thaw, but was similar when moss production was included. Overall, the effect of climate change and permafrost thaw on surface soil decomposition are driven more by precipitation and soil environment than by changes to plant communities. Increasing soil moisture is thereby another mechanism by which permafrost thaw can become a positive feedback to climate change.

Visual soil evaluation - future research requirements

NASA Astrophysics Data System (ADS)

Emmet-Booth, Jeremy; Forristal, Dermot; Fenton, Owen; Ball, Bruce; Holden, Nick

2017-04-01

A review of Visual Soil Evaluation (VSE) techniques (Emmet-Booth et al., 2016) highlighted their established utility for soil quality assessment, though some limitations were identified; (1) The examination of aggregate size, visible intra-porosity and shape forms a key assessment criterion in almost all methods, thus limiting evaluation to structural form. The addition of criteria that holistically examine structure may be desirable. For example, structural stability can be indicated using dispersion tests or examining soil surface crusting, while the assessment of soil colour may indirectly indicate soil organic matter content, a contributor to stability. Organic matter assessment may also indicate structural resilience, along with rooting, earthworm numbers or shrinkage cracking. (2) Soil texture may influence results or impeded method deployment. Modification of procedures to account for extreme texture variation is desirable. For example, evidence of compaction in sandy or single grain soils greatly differs to that in clayey soils. Some procedures incorporate separate classification systems or adjust deployment based on texture. (3) Research into impacts of soil moisture content on VSE evaluation criteria is required. Criteria such as rupture resistance and shape may be affected by moisture content. It is generally recommended that methods are deployed on moist soils and quantification of influences of moisture variation on results is necessary. (4) Robust sampling strategies for method deployment are required. Dealing with spatial variation differs between methods, but where methods can be deployed over large areas, clear instruction on sampling is required. Additionally, as emphasis has been placed on the agricultural production of soil, so the ability of VSE for exploring structural quality in terms of carbon storage, water purification and biodiversity support also requires research. References Emmet-Booth, J.P., Forristal. P.D., Fenton, O., Ball, B.C. & Holden, N.M. 2016. A review of visual soil evaluation techniques for soil structure. Soil Use and Management, 32, 623-634.

Soil microarthropods and their relationship to higher trophic levels in the Pedregal de San Angel Ecological Reserve, Mexico.

PubMed

Callejas-Chavero, Alicia; Castaño-Meneses, Gabriela; Razo-González, María; Pérez-Velázquez, Daniela; Palacios-Vargas, José G; Flores-Martínez, Arturo

2015-01-01

Soil fauna is essential for ecosystem dynamics as it is involved in biogeochemical processes, promotes nutrient availability, and affects the animal communities associated with plants. In this study, we examine the possible relationship between the soil microarthropod community on foliage production and quality of the shrub Pittocaulon praecox. We also examine the arthropods associated to its foliage, particularly the size of the main herbivores and of their natural enemies, at two sites with contrasting vegetation cover and productivity. The diversity of soil microarthropods was assessed from soil samples collected monthly under P. praecox individuals over 13 mo. Specimens collected were identified to species or morphospecies. Shrub foliage productivity was evaluated through the amount of litter produced. Resource quality was assessed by the mean content (percentage by weight) of N, C, S, and P of 30 leaves from each shrub. The mean size of herbivores and their natural enemies were determined by measuring 20 adult specimens of each of the most abundant species. We found a higher species richness of soil microarthropods and foliar arthropods in the open site, although the diversity of foliage arthropods was lower in the closed site. Shrubs growing in the closed site tend to produce more, larger, and nutritionally poorer (lower nitrogen content) leaves than open site. Herbivores and their natural enemies were also larger in the closed site. We found a significant positive relationship between the diversity and species richness of foliar arthropods and the nitrogen content of leaves. In general, species richness and diversity of both the foliar and soil fauna, as well as the size of organisms belonging to higher trophic levels, were affected by vegetation cover and primary productivity at each site. These findings highlight the need to simultaneously consider at least four trophic levels (soil organisms, plants, herbivores, and natural enemies) to better understand the functioning of these systems and their responses to environmental changes. © The Author 2015. Published by Oxford University Press on behalf of the Entomological Society of America.

Impact of edaphic factors and nutrient management on the hepatoprotective efficiency of Carlinoside purified from pigeon pea leaves: An evaluation of UGT1A1 activity in hepatitis induced organelles.

PubMed

Das, Subhasish; Teja, K Charan; Mukherjee, Sandip; Seal, Soma; Sah, Rajesh Kumar; Duary, Buddhadeb; Kim, Ki-Hyun; Bhattacharya, Satya Sundar

2018-02-01

Carlinoside is a unique compound well-known for its excellent curative potential in hepatitis. There is a substantial research gap regarding the medicinal use of carlinoside, as its concentrations are greatly variable (depending on locality). We cultivated Cajanus cajan using vermicompost as a major organic amendment at two locations (Sonitpur and Birbhum) with different soil types, but identical climate conditions. Sonitpur soils were richer in soil organic C (SOC), enzyme activation, and N/P content than Birbhum. However, vermi-treatment improved many soil properties (bulk density, water retention, pH, N/P/K, and enzyme activity) to narrow the locational gap in soil quality by 15-28%. We also recorded a many-fold increment in SOC storage capacities in both locations, which was significantly correlated with carlinoside, total phenol, and flavonoid contents in Cajanus leaves. This significantly up-regulated the carlinoside induced expression of the bilirubin-solubilizing UGT1A1enzyme in HepG2 cell and rat liver. Leaf extracts of vermicompost-aided plants could cure hepatitis in affected rat livers and in the HepG2 cell line. Accordingly, vermi-treatment is an effective route for the growth of Cajanus as a cash crop for biomedical applications and can produce a concurrent improvement in soil quality. Copyright © 2017 Elsevier Inc. All rights reserved.

A biological quality index for volcanic Andisols and Aridisols (Canary Islands, Spain): variations related to the ecosystem degradation.

PubMed

Armas, Cecilia María; Santana, Bayanor; Mora, Juan Luis; Notario, Jesús Santiago; Arbelo, Carmen Dolores; Rodríguez-Rodríguez, Antonio

2007-05-25

The aim of this work is to identify indicators of biological activity in soils from the Canary Islands, by studying the variation of selected biological parameters related to the processes of deforestation and accelerated soil degradation affecting the Canarian natural ecosystems. Ten plots with different degrees of maturity/degradation have been selected in three typical habitats in the Canary Islands: laurel forest, pine forest and xerophytic scrub with Andisols and Aridisols as the most common soils. The studied characteristics in each case include total organic carbon, field soil respiration, mineralized carbon after laboratory incubation, microbial biomass carbon, hot water-extractable carbon and carboxymethylcellulase, beta-d-glucosidase and dehydrogenase activities. A Biological Quality Index (BQI) has been designed on the basis of a regression model using these variables, assuming that the total soil organic carbon content is quite stable in nearly mature ecosystems. Total carbon in mature ecosystems has been related to significant biological variables (hot water-extractable carbon, soil respiration and carboxymethylcellulase, beta-d-glucosidase and dehydrogenase activities), accounting for nearly 100% of the total variance by a multiple regression analysis. The index has been calculated as the ratio of the value calculated from the regression model and the actual measured value. The obtained results show that soils in nearly mature ecosystems have BQI values close to unit, whereas those in degraded ecosystems range between 0.24 and 0.97, depending on the degradation degree.

Carrot, Corn, Lettuce and Soybean Nutrient Contents are ...

EPA Pesticide Factsheets

Biochar, the carbon-rich material remaining after pyrolysis of cellulosic and manure feedstocks, has the potential as a soil amendment to sequester carbon and to improve soil water-holding and nutrient properties- thereby enhancing plant growth. However, biochar produced from some feedstocks also could adversely affect crop quality by changing soil pH and reducing nutrients (e.g., Ca, K, Mg, N, Na, and P) in plant tissues. To evaluate effects of biochar on the nutrient quality of four crops, we conducted a greenhouse study using pots with: carrot (Daucus carota cv. Tendersweet), corn (Zea mays, cv. Golden Bantam), lettuce (Lactuca sativa, cv. Black-Seeded Simpson) and soybean (Glycine max cv. Viking 2265). Plants were grown in one of two South Carolina sandy Coastal Plain soils (Norfolk and Coxville Soil Series), along with biochar (1% by weight) produced from pine chips (PC), poultry litter (PL), swine solids (SS), switchgrass (SG), and two blends of pine chips plus poultry litter (PC/PL, 50/50% and 80/20%). Each of the feedstocks and feedstock blends was pyrolyzed at 350, 500, and 700 ̊ C to produce the biochar used to amend the Norfolk and Coxville soils. Effects of biochar on leaf nutrients (% dry weight) statistically varied with species, soil, feedstock and temperature and nutrient. For carrot and lettuce, the PL, PL/PC, and SS biochars generally decreased leaf N, Ca, Mg, and P; while PL and PL/PC increased K and Na. Biochars had little effect on lea

soil organic matter pools and quality are sensitive to global climate change in tropical forests from India

NASA Astrophysics Data System (ADS)

Mani, Shanmugam; Merino, Agustín; García-Oliva, Felipe; Riotte, Jean; Sukumar, Raman

2016-04-01

Soil organic carbon (SOC) storage and quality are some of the most important factors determining ecological process in tropical forests, which are especially sensitive to global climate change (GCC). In India, the GCC scenarios expect increasing of drought period and wildfire, which may affect the SOC, and therefore the capacity of forest for C sequestration. The aim of the study was to evaluate the amount of soil C and its quality in the mineral soil across precipitation gradient with different factors (vegetation, pH, soil texture and bedrock composition) for generate SOC predictions under GCC. Six soil samples were collected (top 10 cm depth) from 19 1-ha permanent plots in the Mudumalai Wildlife Sanctuary of southern India, which are characterised by four types of forest vegetation (i.e. dry thorn, dry deciduous, moist deciduous and semi-evergreen forest) distributed along to rainfall gradient. The driest sites are dominated by sandy soils, while the soil clay proportion increased in the wet sites. Total organic C (Leco CN analyser), and the SOM quality was assessed by Differential Scanning Calorimetry (DSC) and Solid-state 13CCP-MAS NMR analyses. Soil organic C was positively correlated with precipitation (R2 = 0.502, p<0.01) and with soil clay content (R2 =0.15, p<0.05), and negatively with soil sand content (R2=0.308, p<0.001) and with pH (R2=0.529, p<0.01); while the C/N was only found positive correlation with clay (R2= 0.350, p<0.01). The driest sites (dry thorn forest) has the lowest proportion of thermal combustion of recalcitrant organic matter (Q2,375-475 °C) than the other sites (p<0.05) and this SOC fraction correlated positively with rainfall (R2=0.27, p=0.01). The Q2 model with best fit included rainfall, pH, sand, clay, C and C/N (R2=0.52, p=0.01). Principal component analysis explains 77% of total variance. The sites on the fist component are distributed along the rainfall gradient. These results suggest that the 50% of variance was explained by precipitation and therefore vegetation type. Consequently, the drier sites has a lower C pools with a higher proportion of labile SOC fraction. As a consequence, we expect if the rainfall decreased by GCC could increase SOC mineralization, and therefore reducing the capacity of C sequestration within soil profile.

Soil vital signs: A new Soil Quality Index (SQI) for assessing forest soil health

Treesearch

Michael C. Amacher; Katherine P. O' Neil; Charles H. Perry

2007-01-01

The Forest Inventory and Analysis (FIA) program measures a number of chemical and physical properties of soils to address specific questions about forest soil quality or health. We developed a new index of forest soil health, the soil quality index (SQI), that integrates 19 measured physical and chemical properties of forest soils into a single number that serves as...

Regime Shift by an Exotic Nitrogen-Fixing Shrub Mediates Plant Facilitation in Primary Succession

PubMed Central

Stinca, Adriano; Chirico, Giovanni Battista; Incerti, Guido; Bonanomi, Giuliano

2015-01-01

Ecosystem invasion by non-native, nitrogen-fixing species is a global phenomenon with serious ecological consequences. However, in the Mediterranean basin few studies addressed the impact of invasion by nitrogen-fixing shrubs on soil quality and hydrological properties at local scale, and the possible effects on succession dynamics and ecosystem invasibility by further species. In this multidisciplinary study we investigated the impact of Genista aetnensis (Biv.) DC., an exotic nitrogen-fixing shrub, on the Vesuvius Grand Cone (Southern Italy). Specifically, we tested the hypotheses that the invasion of G. aetnensis has a significant impact on soil quality, soil hydrological regime, local microclimate and plant community structure, and that its impact increases during the plant ontogenetic cycle. We showed that G. aetnensis, in a relatively short time-span (i.e. ~ 40 years), has been able to build-up an island of fertility under its canopy, by accumulating considerable stocks of C, N, and P in the soil, and by also improving the soil hydrological properties. Moreover, G. aetnensis mitigates the daily range of soil temperature, reducing the exposure of coexisting plants to extremely high temperatures and water loss by soil evaporation, particularly during the growing season. Such amelioration of soil quality, coupled with the mitigation of below-canopy microclimatic conditions, has enhanced plant colonization of the barren Grand Cone slopes, by both herbaceous and woody species. These results suggest that the invasion of G. aetnensis could eventually drive to the spread of other, more resource-demanding exotic species, promoting alternative successional trajectories that may dramatically affect the local landscape. Our study is the first record of the invasion of G. aetnensis, an additional example of the regime shifts driven by N-fixing shrubs in Mediterranean region. Further studies are needed to identity specific management practices that can limit the spread and impacts of this species. PMID:25835015

Quinoa Seed Quality Response to Sodium Chloride and Sodium Sulfate Salinity

PubMed Central

Wu, Geyang; Peterson, Adam J.; Morris, Craig F.; Murphy, Kevin M.

2016-01-01

Quinoa (Chenopodium quinoa Willd.) is an Andean crop with an edible seed that both contains high protein content and provides high quality protein with a balanced amino acid profile in embryonic tissues. Quinoa is a halophyte adapted to harsh environments with highly saline soil. In this study, four quinoa varieties were grown under six salinity treatments and two levels of fertilization, and then evaluated for quinoa seed quality characteristics, including protein content, seed hardness, and seed density. Concentrations of 8, 16, and 32 dS m-1 of NaCl and Na2SO4, were applied to the soil medium across low (1 g N, 0.29 g P, 0.29 g K per pot) and high (3 g N, 0.85 g P, 0.86 g K per pot) fertilizer treatments. Seed protein content differed across soil salinity treatments, varieties, and fertilization levels. Protein content of quinoa grown under salinized soil ranged from 13.0 to 16.7%, comparable to that from non-saline conditions. NaCl and Na2SO4 exhibited different impacts on protein content. Whereas the different concentrations of NaCl did not show differential effects on protein content, the seed from 32 dS m-1 Na2SO4 contained the highest protein content. Seed hardness differed among varieties, and was moderately influenced by salinity level (P = 0.09). Seed density was affected significantly by variety and Na2SO4 concentration, but was unaffected by NaCl concentration. The samples from 8 dS m-1 Na2SO4 soil had lower density (0.66 g/cm3) than those from 16 dS m-1 and 32 dS m-1 Na2SO4, 0.74 and 0.72g/cm3, respectively. This paper identifies changes in critical seed quality traits of quinoa as influenced by soil salinity and fertility, and offers insights into variety response and choice across different abiotic stresses in the field environment. PMID:27375648

Decomposition of Phragmites australis rhizomes in artificial land-water transitional zones (ALWTZs) and management implications

NASA Astrophysics Data System (ADS)

Han, Zhen; Cui, Baoshan; Zhang, Yongtao

2015-09-01

Rhizomes are essential organs for growth and expansion of Phragmites australis. They function as an important source of organic matter and as a nutrient source, especially in the artificial land-water transitional zones (ALWTZs) of shallow lakes. In this study, decomposition experiments on 1- to 6-year-old P. australis rhizomes were conducted in the ALWTZ of Lake Baiyangdian to evaluate the contribution of the rhizomes to organic matter accumulation and nutrient release. Mass loss and changes in nutrient content were measured after 3, 7, 15, 30, 60, 90, 120, and 180 days. The decomposition process was modeled with a composite exponential model. The Pearson correlation analysis was used to analyze the relationships between mass loss and litter quality factors. A multiple stepwise regression model was utilized to determine the dominant factors that affect mass loss. Results showed that the decomposition rates in water were significantly higher than those in soil for 1- to 6-year-old rhizomes. However, the sequence of decomposition rates was identical in both water and soil. Significant relationships between mass loss and litter quality factors were observed at a later stage, and P-related factors proved to have a more significant impact than N-related factors on mass loss. According to multiple stepwise models, the C/P ratio was found to be the dominant factor affecting the mass loss in water, and the C/N and C/P ratios were the main factors affecting the mass loss in soil. The combined effects of harvesting, ditch broadening, and control of water depth should be considered for lake administrators.

Microbial communities may modify how litter quality affects potential decomposition rates as tree species migrate

Treesearch

Ashley D. Keiser; Jennifer D. Knoepp; Mark A. Bradford

2013-01-01

Background and aims Climate change alters regional plant species distributions, creating new combinations of litter species and soil communities. Biogeographic patterns in microbial communities relate to dissimilarity in microbial community function, meaning novel litters to communities may decompose differently than predicted from their chemical composition. Therefore...

Evaluation of the halophyte Salsola soda as an alternative crop for saline soils high in selenium and boron

USDA-ARS?s Scientific Manuscript database

Salinization is one important factor contributing to land degradation, which affects agricultural production and environmental quality, especially in the West side of central California. When salinization is combined with a natural contamination of trace elements (i.e., Se and B) in arid and semi-ar...

Cover crops and tillage in a mature Merlot vineyard affect yields and cluster weight but not nutrition

USDA-ARS?s Scientific Manuscript database

Permanent cover crops are commonly used in vineyard floor management because of their beneficial effects to soil and vine health, but studies evaluating their competitive effects on vines have been conducted primarily in non-irrigated vineyards. Future air quality regulations could mandate the use o...

Diet influences rates of carbon and nitrogen mineralization from decomposing grasshopper frass and cadavers

USDA-ARS?s Scientific Manuscript database

Insect herbivory can produce a pulse of mineral nitrogen (N) in soil from the decomposition of frass and cadavers. In this study we examined how diet quality affects rates of N and carbon (C) mineralization from grasshopper frass and cadavers. Frass was collected from grasshoppers fed natural or mer...

Dynamics of organic matter and microbial populations in amended soil: a multidisciplinary approach

NASA Astrophysics Data System (ADS)

Gigliotti, Giovanni; Pezzolla, Daniela; Zadra, Claudia; Albertini, Emidio; Marconi, Gianpiero; Turchetti, Benedetta; Buzzini, Pietro

2013-04-01

The application of organic amendments to soils, such as pig slurry, sewage sludge and compost is considered a tool for improving soil fertility and enhancing C stock. The addition of these different organic materials allows a good supply of nutrients for plants but also contributes to C sequestration, affects the microbial activity and the transformation of soil organic matter (SOM). Moreover, the addition of organic amendment has gained importance as a source of greenhouse gas (GHG) emissions and then as a cause of the "Global Warming". Therefore, it is important to investigate the factors controlling the SOM mineralization in order to improve soil C sequestration and decreasing at the same time the GHG emissions. The quality of organic matter added to the soil will play an important role in these dynamics, affecting the microbial activity and the changes in microbial community structure. A laboratory, multidisciplinary experiment was carried out to test the effect of the amendment by anaerobic digested livestock-derived organic materials on labile organic matter evolution and on dynamics of microbial population, this latter both in terms of consistence of microbial biomass, as well as in terms of microbial biodiversity. Different approaches were used to study the microbial community structure: chemical (CO2 fluxes, WEOC, C-biomass, PLFA), microbiological (microbial enumeration) and molecular (DNA extraction and Roche 454, Next Generation Sequencing, NGS). The application of fresh digestate, derived from the anaerobic treatment of animal wastes, affected the short-term dynamics of microbial community, as reflected by the increase of CO2 emissions immediately after the amendment compared to the control soil. This is probably due to the addition of easily available C added with the digestate, demonstrating that this organic material was only partially stabilized by the anaerobic process. In fact, the digestate contained a high amounts of available C, which led to increase WEOC concentration in digestate treated soil compared to the control soil. The depletion of C, likely due to the microbial activity, was confirmed by the gradual decrease of WEOC concentration in soils amended with digestate. The SUVA254 measurement showed an influence of digestate on the quality of soil WEOM, with higher values in the control rather than in the digestate amended soil, indicating a great amount of aromatic compounds in native SOM. The results of the PLFAs showed that the addition of digestate did not lead overall changes in the microbial community structure compared to the control, except for a shallow decrease of fungi. This probably suggests that the slow rate of mineralization of the organic matter added with digestate does not induce to a rapid shift of microbial community structure. The NGS showed the most important bacterial phyla and fungi species that were involved in the SOM turnover. Furthermore, this approach might be useful to trace the residence time of microbial pathogens supplied with digestates.

Geochemical characterization of elements in Vitis vinifera cv. Negroamaro grape berries grown under different soil managements.

PubMed

Pepi, Salvatore; Coletta, Antonio; Crupi, Pasquale; Leis, Marilena; Russo, Sabrina; Sansone, Luigi; Tassinari, Renzo; Chicca, Milvia; Vaccaro, Carmela

2016-04-01

The present geochemical study concerns the impact of viticultural practices in the chemical composition of the grape cultivar "Negroamaro" in Apulia, a southern Italian region renowned for its quality wine. Three types of soil management (SM), two cover cropping with different mixtures, and a soil tillage were considered. For each SM, the vines were irrigated according to two irrigation levels. Chemical composition of soil and of berries of Vitis vinifera cultivar "Negroamaro" were analyzed by X-ray fluorescence, inductively coupled plasma-mass spectrometry and multivariate statistics (linear discrimination analysis). In detail, we investigated major and trace elements behavior in the soil according to irrigation levels, the related index of bioaccumulation (BA) and the relationship between trace element concentration and soil management in "Negroamaro" grapes. The results indicate that soil management affects the mobility of major and trace elements. A specific assimilation of these elements in grapes from vines grown under different soil management was confirmed by BA. Multivariate statistics allowed to associate the vines to the type of soil management. This geochemical characterization of elements could be useful to develop fingerprints of vines of the cultivar "Negroamaro" according to soil management and geographical origin.

In situ assessment of phytotechnologies for multicontaminated soil management.

PubMed

Ouvrard, S; Barnier, C; Bauda, P; Beguiristain, T; Biache, C; Bonnard, M; Caupert, C; Cébron, A; Cortet, J; Cotelle, S; Dazy, M; Faure, P; Masfaraud, J F; Nahmani, J; Palais, F; Poupin, P; Raoult, N; Vasseur, P; Morel, J L; Leyval, C

2011-01-01

Due to human activities, large volumes of soils are contaminated with organic pollutants such as polycyclic aromatic hydrocarbons, and very often by metallic pollutants as well. Multipolluted soils are therefore a key concern for remediation. This work presents a long-term evaluation of the fate and environmental impact of the organic and metallic contaminants of an industrially polluted soil under natural and plant-assisted conditions. A field trial was followed for four years according to six treatments in four replicates: unplanted, planted with alfalfa with or without mycorrhizal inoculation, planted with Noccaea caerulescens, naturally colonized by indigenous plants, and thermally treated soil planted with alfalfa. Leaching water volumes and composition, PAH concentrations in soil and solutions, soil fauna and microbial diversity, soil and solution toxicity using standardized bioassays, plant biomass, mycorrhizal colonization, were monitored. Results showed that plant cover alone did not affect total contaminant concentrations in soil. However, it was most efficient in improving the contamination impact on the environment and in increasing the biological diversity. Leaching water quality remained an issue because of its high toxicity shown by micro-algae testing. In this matter, prior treatment of the soil by thermal desorption proved to be the only effective treatment.

Impacts of agricultural management practices on soil quality in Europe and China - an assessment within the framework of the EU iSQAPER project

NASA Astrophysics Data System (ADS)

Alaoui, Abdallah; Schwilch, Gudrun; Barão, Lúcia; Basch, Gottlieb; Sukkel, Wijnand; Lemesle, Julie; Ferreira, Carla; Garcia-Orenes, Fuensanta; Morugan, Alicia; Mataix, Jorge; Kosmas, Costas; Glavan, Matjaž; Tóth, Brigitta; Petrutza Gate, Olga; Lipiec, Jerzy; Reintam, Endla; Xu, Minggang; Di, Jiaying; Fan, Hongzhu; Geissen, Violette

2017-04-01

Agricultural soils are under a wide variety of pressures, including from increasing global demand for food associated with population growth, changing diets, land degradation, and associated productivity reductions potentially exacerbated by climate change. To manage the use of agricultural soils well, decision-makers need science-based, easily applicable, and cost-effective tools for assessing soil quality and soil functions. Since a practical assessment of soil quality requires the integrated consideration of key soil properties and their variations in space and time, providing such tools remains a challenging task. This study aims to assess the impact of innovative agricultural management practices on soil quality in 14 study sites across Europe (10) and China (4), covering the major pedo-climatic zones. The study is part of the European H2020 project iSQAPER, which involves 25 partners across Europe and China and is coordinated by Wageningen University, The Netherlands. iSQAPER is aimed at interactive soil quality assessment in Europe and China for agricultural productivity and environmental resilience. The study began with a thorough literature analysis to inform the selection of indicators for the assessment of soil structure and soil functions. A manual was then developed in order to standardize and facilitate the task of inventorying soil quality and management practices at the case study sites. The manual provides clear and precise instructions on how to assess the 11 selected soil quality indicators based on a visual soil assessment methodology. A newly developed infiltrometer was used to easily assess the soil infiltration capacity in the field and investigate hydrodynamic flow processes. Based on consistent calibration, the infiltrometer enables reliable prediction of key soil hydraulic properties. The main aim of this inventory is to link agricultural management practices to the soil quality status at the case study sites, and to identify innovative practices that have improved soil quality. The inventory and the scoring of soil quality are done together with land users at each study site. The idea is to compare the soil quality on a farm where management practices have changed 3 or more years ago with that on a control farm where practices have not changed, with both farms located in the same pedo-climatic zone and having comparable soil conditions. The case study partners were requested to identify at least 3 newly adopted management practices (or combinations thereof) and 3 related control farms. First results show that among 88 sets of paired plots, 60 pairs (68 %) show a positive impact of innovative agricultural management practices on soil quality. 18 pairs (21 %) do not show any difference in soil quality between soils under innovative practices and soils in the control plots, and the remaining 10 plots (11 %) show an inverse effect. The non-detectable effect of the innovative practices on soil quality are due to type of tillage management, soil type and fertility that mask the effect of management practices on soil and also due to time of the assessment. This assessment will be repeated in the coming years, with the aim of providing sound data on soil quality and its improvement through innovative management practices across Europe and China.

Changes in soil nitrogen cycling under Norway spruce logging residues on a clear-cut

NASA Astrophysics Data System (ADS)

Smolander, Aino; Lindroos, Antti-Jussi; Kitunen, Veikko

2016-04-01

In Europe, forest biomass is increasingly being used as a source of energy to replace fossil fuels. In practice, this means that logging residues, consisting of green branches and stem tops, are more commonly harvested. In 2012 logging residues were harvested from about one third of clear-cuts in Finland. Our aim was to study how logging residues affect soil organic matter quality, in particular soil N cycling processes and composition of certain groups of plant secondary compounds, tannins and terpenes. Compounds in these groups were of interest because they are abundant in logging residues, and they have been shown to control soil N cycling. In connection with clear-cutting a Norway spruce stand in southern Finland, we established a controlled field experiment by building logging residue piles (40 kg/m2) on study plots. The piles consisted of fresh spruce branches and tops with green foliage. Control plots with no residues were included (0 kg/m2). Changes in soil organic matter properties have now been monitored for three growing seasons. Logging residues affected organic layer properties strongly. For example, they increased net nitrification and nitrate concentrations. There were also increases in the concentrations of certain terpenes and condensed tannins due to the residues. The significance of logging residues on soil processes and properties will be shown.

Effect of soil cadmium on growth, photosynthesis and quality of Raphanus sativus and Lactuca sativa.

PubMed

Kaur, Navjyot; Jhanji, Shalini

2016-09-01

Cadmium (Cd) raises serious concerns as its accumulation in the plant not only affect the growth and quality of plant but also threaten the health of consumers. In this research, two vegetables, i.e., radish (Raphanus sativus L.) and lettuce (Lactuca sativa L), were planted in pots having soil treated with Cd as Cd (NO3)2 at different doses (25, 50, 100 and 200 mg Cd kg-1 soil ) to investigate the influence of cadmium on their growth, photosynthetic attributes and quality. Cadmium retarded plant growth as dry weight of radish roots decline by 87% and leaves by 83% following 200 mg Cd kg-1 soil application and the corresponding values for lettuce were 64 and 69% respectively. Significant reductions in various photosynthetic parameters viz., leaf area per plant, total chlorophyll, Chl a and Chl b content were also recorded with Cd applications. The Cd treatments resulted in loss of membrane integrity as revealed by significant increase in electrolyte leakage in leaves of both vegetables. There was significant increase in Cd accumulation in radish and lettuce with all applications but no visual symptoms of Cd toxicity were noticed with 25 and 50 mg Cd kg-1 soil application except for yield differences, illustrating that Cd accumulate in this crop without visual evidence of its presence. However, toxicity symptoms in the form of interveinal chlorosis of the leaf lamina, followed by necrosis and leaf rolling, were clearly evident with 100 and 200 mg Cd kg-1 soil application. Apparently, Cd causes harm due to its phytotoxic effects and high accumulation in edible parts of radish and lettuce without any visible symptoms that constitutes a substantial hazard to human health.

Unravel biophysical factors on river water quality response in Chilean Central-Southern watersheds.

PubMed

Yevenes, Mariela A; Arumí, José L; Farías, Laura

2016-05-01

Identifying the key anthropogenic (land uses) and natural (topography and climate) biophysical drivers affecting river water quality is essential for efficient management of water resources. We tested the hypothesis that water quality can be predicted by different biophysical factors. Multivariate statistics based on a geographical information system (GIS) were used to explore the influence of factors (i.e., precipitation, topography, and land uses) on water quality (i.e., nitrate (NO 3 (-)), phosphate (PO 4 (3-)), silicate (Si(OH)4), dissolved oxygen (DO), suspended solids (TSS), biological oxygen demand (DO), temperature (T), conductivity (EC), and pH) for two consecutive years in the Itata and Biobío river watersheds, Central Chile (36° 00' and 38° 30'). The results showed that (NO 3 (-)), (PO 4 (3-)), Si(OH)4, TSS, EC, and DO were higher during rainy season (austral fall, winter, and spring), whereas BOD and temperature were higher during dry season. The spatial variation of these parameters in both watersheds was related to land use, topography (e.g., soil moisture, soil hydrological group, and erodability), and precipitation. Soil hydrological group and soil moisture were the strongest explanatory predictors for PO 4 (3-) , Si(OH)4 and EC in the river, followed by land use such as agriculture for NO 3 (-) and DO and silviculture for TSS and Si(OH)4. High-resolution water leaching and runoff maps allowed us to identify agriculture areas with major probability of water leaching and higher probability of runoff in silviculture areas. Moreover, redundancy analysis (RDA) revealed that land uses (agriculture and silviculture) explained in 60 % the river water quality variation. Our finding highlights the vulnerability of Chilean river waters to different biophysical drivers, rather than climate conditions alone, which is amplified by human-induced degradation.

Application of soil quality indices to assess the status of agricultural soils irrigated with treated wastewaters

NASA Astrophysics Data System (ADS)

Morugán-Coronado, A.; Arcenegui, V.; García-Orenes, F.; Mataix-Solera, J.; Mataix-Beneyto, J.

2012-12-01

The supply of water is limited in some parts of the Mediterranean region, such as southeastern Spain. The use of treated wastewater for the irrigation of agricultural soils is an alternative to using better-quality water, especially in semi-arid regions. On the other hand, this practice can modify some soil properties, change their relationships, the equilibrium reached and influence soil quality. In this work two soil quality indices were used to evaluate the effects of irrigation with treated wastewater in soils. The indices were developed studying different soil properties in undisturbed soils in SE Spain, and the relationships between soil parameters were established using multiple linear regressions. This study was carried out in three areas of Alicante Province (SE Spain) irrigated with wastewater, including four study sites. The results showed slight changes in some soil properties as a consequence of irrigation with wastewater, the obtained levels not being dangerous for agricultural soils, and in some cases they could be considered as positive from an agronomical point of view. In one of the study sites, and as a consequence of the low quality wastewater used, a relevant increase in soil organic matter content was observed, as well as modifications in most of the soil properties. The application of soil quality indices indicated that all the soils of study sites are in a state of disequilibrium regarding the relationships between properties independent of the type of water used. However, there were no relevant differences in the soil quality indices between soils irrigated with wastewater with respect to their control sites for all except one of the sites, which corresponds to the site where low quality wastewater was used.

Effects of Pb Smelting on the Soil Bacterial Community near a Secondary Lead Plant.

PubMed

Luo, Zhanbin; Ma, Jing; Chen, Fu; Li, Xiaoxiao; Zhang, Shaoliang

2018-05-20

Secondary lead smelting is a widespread industrial activity which has exacerbated Pb or Cd contamination of soil and water across the world. Soil physicochemical properties, soil enzyme activities, heavy metal concentrations, and bacterial diversity near a secondary lead plant in Xuzhou, China were examined in this study. The results showed that secondary lead smelting activities influenced nearby soils. Soil acidification decreased one order of magnitude, with a mean value of 7.3. Soil organic matter also showed a downward trend, while potassium and nitrogen appeared to accumulate. Soil urease and protease activity increased in samples with greater heavy metal pollution, but overall the soil microbial biodiversity decreased. Soil heavy metal concentration-especially Pb and Cd-greatly exceeded the concentrations of Chinese Environmental Quality Standard for Soils (GB 15618-1995). Some environmental factors-such as pH, organic matter, enzyme activity, and the concentration of heavy metals-significantly affected bacterial diversity: compared with the control site, the Chao1 estimator decreased about 50%, while the Shannon diversity index dropped approximately 20%. Moreover, some genera have significant relationships with heavy metal concentration-such as Ramlibacter with Zn and Steroidobacter with Cd-which might act as bio-indicators for soil remediation. These results will provide a new insight in the future for reclaiming soil contaminants caused by secondary lead smelting.

Study on a pattern classification method of soil quality based on simplified learning sample dataset

USGS Publications Warehouse

Zhang, Jiahua; Liu, S.; Hu, Y.; Tian, Y.

2011-01-01

Based on the massive soil information in current soil quality grade evaluation, this paper constructed an intelligent classification approach of soil quality grade depending on classical sampling techniques and disordered multiclassification Logistic regression model. As a case study to determine the learning sample capacity under certain confidence level and estimation accuracy, and use c-means algorithm to automatically extract the simplified learning sample dataset from the cultivated soil quality grade evaluation database for the study area, Long chuan county in Guangdong province, a disordered Logistic classifier model was then built and the calculation analysis steps of soil quality grade intelligent classification were given. The result indicated that the soil quality grade can be effectively learned and predicted by the extracted simplified dataset through this method, which changed the traditional method for soil quality grade evaluation. ?? 2011 IEEE.

Root endophytic fungus Piriformospora indica affected growth, cadmium partitioning and chlorophyll fluorescence of sunflower under cadmium toxicity.

PubMed

Shahabivand, Saleh; Parvaneh, Azar; Aliloo, Ali Asghar

2017-11-01

Cadmium (Cd) pollution in the soil threatens the quality of environmental health, and deleteriously affects physiological activities of crops. Symbiosis of endophytic fungi with various plants is a promising manner to improving numerous plant characteristics and remediating heavy metal-polluted soils. In this pot experiment, the influence of root endophyte fungus Piriformospora indica on growth, physiological parameters and organs Cd accumulation in sunflower cv. Zaria plants under the toxic levels of Cd (0, 40, 80 and 120mg/kg soil) were studied. Increasing Cd concentration in the soil reduced growth parameters, chlorophyll (Chl) a and Chl b contents, and Fv/Fm and ETR (electron transport rate) values, but increased root, stem and leaf Cd accumulation, and proline content. The presence of P. indica significantly enhanced growth, Chl a, Chl b and proline contents, and Fv/Fm and ETR values. Compared to non-inoculated ones, P. indica-inoculated plants had higher Cd accumulation in root, whereas lower Cd accumulation in stem and leaf. The present study strongly supports the established ability of P. indica to alleviate Cd toxicity by improving the physiological status in sunflower. Furthermore, this endophyte fungus can be useful for Cd phyto-stabilization in sunflower roots in contaminated soils. Copyright © 2017 Elsevier Inc. All rights reserved.

Depth Effects on the Decomposition Dynamics of Plant-derived C at Diverse Sites

NASA Astrophysics Data System (ADS)

Gregorich, E.; Ellert, B.; Janzen, H.; Beare, M.; Helgason, B. L.; Curtin, D.

2017-12-01

Decay of plant residues is tied to many ecosystem functions and affects atmospheric CO2, plant-available nutrients, microbial diversity, soil organic matter quality, among others. The rate of decay, in turn, is governed by soil type and management, location in the soil profile, and environmental variables, some of which may be changing in coming decades. Our objective in this study was to elucidate the decomposition dynamics of plant-derived C and N at different soil depths. To characterize the importance of these variables across a broad scale, we established a long-term study at two sites in Canada and one site in New Zealand. At each site, labelled barley straw (13C = 10.2 atom%,C = 37.9%; N = 0.95%; C:N = 40) was installed at 3 depths (5-10, 20-25 and 40-45 cm). Soil temperature was logged at each depth. Samples were collected at different times over 5-6 years after application of the residues. Results showed that substantial decay occurred at all depths within a relatively short time (< 1 year). Decay was greatest at the warmest site and depth affected the concentration of viable microbes. However, depth had no effect on residue decay after about 5 years.

Risk assessment and source analysis of soil heavy metal pollution from lower reaches of Yellow River irrigation in China.

PubMed

Zhang, Pengyan; Qin, Chengzhe; Hong, Xin; Kang, Guohua; Qin, Mingzhou; Yang, Dan; Pang, Bo; Li, Yanyan; He, Jianjian; Dick, Richard P

2018-08-15

The level of concentration of heavy metal in soil is detrimental to soil quality. The Heigangkou-Liuyuankou irrigation area in the lower-reach of Yellow River irrigation, as home to a large population and a major site to agricultural production, is vulnerable to heavy metal pollution. This study examined soil quality in Heigangkou-Liuyuankou irrigation areas of Kaifeng, China. Pollution in soil and potential risks introduced by heavy metal accumulation were assessed using Nemerow, Geoaccumulation, and Hakanson's ecological risk indices. Statistics and Geographic Information Systems (GIS) were used to model and present the spatiotemporal changes of the pollution sources and factors affecting the levels of pollution. The heavy metals found in the sampled soil are Cr, Ni, Cu, Zn, Cd, Pb, As, and Hg. Among them, Cd is more concentrated than the others. The southwestern region of the studied area confronts the most serious heavy metal pollution. There exist spatial disparities of low concentrations of different heavy metals in the study area. Hg and Cd are found to pose the highest potential ecological risks. However, their risk levels are not the same across the study area. Levels concentration of Ni, Cu, Zn, Cd, Pb, As, and Hg in soil are highly correlated. In combination, they post an additional threat to the ecological environment. Transportation, rural settlements, and water bodies are found to be the major sources of Cr, Ni, Cu, Zn, Cd, Pb, and Hg pollution in the soil; among the major sources, transportation is the most significant factor. Copyright © 2018 Elsevier B.V. All rights reserved.

A conceptual framework for effectively anticipating water-quality changes resulting from changes in agricultural activities

USGS Publications Warehouse

Capel, Paul D.; Wolock, David M.; Coupe, Richard H.; Roth, Jason L.

2018-01-10

Agricultural activities can affect water quality and the health of aquatic ecosystems; many water-quality issues originate with the movement of water, agricultural chemicals, and eroded soil from agricultural areas to streams and groundwater. Most agricultural activities are designed to sustain or increase crop production, while some are designed to protect soil and water resources. Numerous soil- and water-protection practices are designed to reduce the volume and velocity of runoff and increase infiltration. This report presents a conceptual framework that combines generalized concepts on the movement of water, the environmental behavior of chemicals and eroded soil, and the designed functions of various agricultural activities, as they relate to hydrology, to create attainable expectations for the protection of—with the goal of improving—water quality through changes in an agricultural activity.The framework presented uses two types of decision trees to guide decision making toward attainable expectations regarding the effectiveness of changing agricultural activities to protect and improve water quality in streams. One decision tree organizes decision making by considering the hydrologic setting and chemical behaviors, largely at the field scale. This decision tree can help determine which agricultural activities could effectively protect and improve water quality in a stream from the movement of chemicals, or sediment, from a field. The second decision tree is a chemical fate accounting tree. This decision tree helps set attainable expectations for the permanent removal of sediment, elements, and organic chemicals—such as herbicides and insecticides—through trapping or conservation tillage practices. Collectively, this conceptual framework consolidates diverse hydrologic settings, chemicals, and agricultural activities into a single, broad context that can be used to set attainable expectations for agricultural activities. This framework also enables better decision making for future agricultural activities as a means to reduce current, and prevent new, water-quality issues.

Ecological evaluation of rangeland quality in dry subtropics of Azerbaijan

NASA Astrophysics Data System (ADS)

Gasanova, A. F.

2014-12-01

The results of ecological evaluation of soil-landscape complexes of winter rangelands of Gobustan with the use of energy criteria are discussed. The diagnostic characteristics of soil fertility and correction coefficients for the thickness of texture of soil horizons, soil salinization, soil erosion, and microelemental composition of soils have been used to separate the soils of winter rangelands into several quality groups. A larger part of the soils belongs to the medium quality group with the mean weighted quality factor (bonitet) of 52. Special assessment scales have been suggested for the differential ecological assessment and monitoring of the rangelands. In the past 40 years, the area of steppe landscapes has decreased from 22.7 to 12%, whereas the area of semideserts has increased up to 64%. The area of best-quality soils within the studied rangelands had decreased by three times, and their average quality factor has decreased from 92 to 86.

Monitoring of Urban Soil Contamination under Various Technogenic Impact: Comparison of the Two Seaside Cities

NASA Astrophysics Data System (ADS)

Miroshnychenko, Mykola; Krivitska, Ivetta; Hladkikh, Yevgenia

2017-04-01

The aim of the research was to show how the environmental policy of city can affect the quality of soils. Studies were carried out simultaneously in the two cities of Ukrainian coast of the Azov Sea, which are significantly different in terms of technogenic impact. Berdyansk is a well known resort and wellness center, but until recently around 30 petrochemical, machine-building and other enterprises were located there. The largest industrial center Mariupol, where emissions from enterprises to the atmosphere exceed 300 thousand tons per year, is located about 60 km from Berdyansk in similar natural conditions. Observations of soil contamination was performed on 60 monitoring sites not less than 2500 m2, located in industrial, administrative, cultural, residential and recreational zones of each city. The time series of observations: the first stage in 2002-2003, the second in 2007-2008, third in 2012-2014. The available forms of heavy metals in the soils were determined by atomic-absorption method after extraction of buffer solution with pH 4.8 as well as 1 N HCl. The content of mineral salts in a water extract was measured titrimetrically. The content of heavy metals in grass vegetation and phytotoxicity of soil was determined in 50% of monitoring sites. Since 2002-2003, the level of soil contamination in the industrial zones of Berdyansk gradually decreased, but heavy metals began accumulate in soils of residential, cultural and administrative areas, and especially, in recreation objects. Probably, this is related to the reduction of the industrial sector and the increase of resort and tourist business. Consequently, the content of cadmium, chromium, and nickel in soils is reduced, but the content of micronutrients (Zn, Cu, Mn) increases. Currently the contamination of plants becomes less so the quality of local agricultural products is improved. In contrast to this, due to the intensive activity of the enterprises of iron and steel industry in Mariupol the level of soil contamination in industrial, residential areas and parks has increased by 8-18%. This is caused by the accumulation of zinc, manganese, lead and mineral salts, sometimes in excess of the permitted rate. The contamination of plants in Mariupol is higher than soil contamination due to deposition of heavy metals directly from the atmosphere. Phytotoxicity effect has been discovered on the most of monitoring sites. Conclusions. Due to extremely high heterogeneity and combination of pollution from multiple sources, the changes of urban soil quality can be objectively assessed using observations which are systematic in space and time. The quality of urban soils is improving over five-ten years after reducing the amount of industrial pollution, but heavy metals are continuing to dissipate from the industrial zone to the surrounding land. Soil quality is deteriorating significantly in case of a constant dominance of the steel industry over other activities.

Saltwater intrusion into tidal freshwater marshes alters the biogeochemical processing of organic carbon

NASA Astrophysics Data System (ADS)

Neubauer, S. C.; Franklin, R. B.; Berrier, D. J.

2013-07-01

Environmental perturbations in wetlands affect the integrated plant-microbial-soil system, causing biogeochemical responses that can manifest at local to global scales. The objective of this study was to determine how saltwater intrusion affects carbon mineralization and greenhouse gas production in coastal wetlands. Working with tidal freshwater marsh soils that had experienced roughly 3.5 yr of in situ saltwater additions, we quantified changes in soil properties, measured extracellular enzyme activity associated with organic matter breakdown, and determined potential rates of anaerobic carbon dioxide (CO2) and methane (CH4) production. Soils from the field plots treated with brackish water had lower carbon content and higher C : N ratios than soils from freshwater plots, indicating that saltwater intrusion reduced carbon availability and increased organic matter recalcitrance. This was reflected in reduced activities of enzymes associated with the hydrolysis of cellulose and the oxidation of lignin, leading to reduced rates of soil CO2 and CH4 production. The effects of long-term saltwater additions contrasted with the effects of short-term exposure to brackish water during three-day laboratory incubations, which increased rates of CO2 production but lowered rates of CH4 production. Collectively, our data suggest that the long-term effect of saltwater intrusion on soil CO2 production is indirect, mediated through the effects of elevated salinity on the quantity and quality of autochthonous organic matter inputs to the soil. In contrast, salinity, organic matter content, and enzyme activities directly influence CH4 production. Our analyses demonstrate that saltwater intrusion into tidal freshwater marshes affects the entire process of carbon mineralization, from the availability of organic carbon through its terminal metabolism to CO2 and/or CH4, and illustrate that long-term shifts in biogeochemical functioning are not necessarily consistent with short-term disturbance-type responses.

Saltwater intrusion into tidal freshwater marshes alters the biogeochemical processing of organic carbon

NASA Astrophysics Data System (ADS)

Neubauer, S. C.; Franklin, R. B.; Berrier, D. J.

2013-12-01

Environmental perturbations in wetlands affect the integrated plant-microbial-soil system, causing biogeochemical responses that can manifest at local to global scales. The objective of this study was to determine how saltwater intrusion affects carbon mineralization and greenhouse gas production in coastal wetlands. Working with tidal freshwater marsh soils that had experienced ~ 3.5 yr of in situ saltwater additions, we quantified changes in soil properties, measured extracellular enzyme activity associated with organic matter breakdown, and determined potential rates of anaerobic carbon dioxide (CO2) and methane (CH4) production. Soils from the field plots treated with brackish water had lower carbon content and higher C : N ratios than soils from freshwater plots, indicating that saltwater intrusion reduced carbon availability and increased organic matter recalcitrance. This was reflected in reduced activities of enzymes associated with the hydrolysis of cellulose and the oxidation of lignin, leading to reduced rates of soil CO2 and CH4 production. The effects of long-term saltwater additions contrasted with the effects of short-term exposure to brackish water during three-day laboratory incubations, which increased rates of CO2 production but lowered rates of CH4 production. Collectively, our data suggest that the long-term effect of saltwater intrusion on soil CO2 production is indirect, mediated through the effects of elevated salinity on the quantity and quality of autochthonous organic matter inputs to the soil. In contrast, salinity, organic matter content, and enzyme activities directly influence CH4 production. Our analyses demonstrate that saltwater intrusion into tidal freshwater marshes affects the entire process of carbon mineralization, from the availability of organic carbon through its terminal metabolism to CO2 and/or CH4, and illustrate that long-term shifts in biogeochemical functioning are not necessarily consistent with short-term disturbance-type responses.

Effects of Manure Compost Application on Soil Microbial Community Diversity and Soil Microenvironments in a Temperate Cropland in China

PubMed Central

Zhen, Zhen; Liu, Haitao; Wang, Na; Guo, Liyue; Meng, Jie; Ding, Na; Wu, Guanglei; Jiang, Gaoming

2014-01-01

The long-term application of excessive chemical fertilizers has resulted in the degeneration of soil quality parameters such as soil microbial biomass, communities, and nutrient content, which in turn affects crop health, productivity, and soil sustainable productivity. The objective of this study was to develop a rapid and efficient solution for rehabilitating degraded cropland soils by precisely quantifying soil quality parameters through the application of manure compost and bacteria fertilizers or its combination during maize growth. We investigated dynamic impacts on soil microbial count, biomass, basal respiration, community structure diversity, and enzyme activity using six different treatments [no fertilizer (CK), N fertilizer (N), N fertilizer + bacterial fertilizer (NB), manure compost (M), manure compost + bacterial fertilizer (MB), and bacterial fertilizer (B)] in the plowed layer (0–20 cm) of potted soil during various maize growth stages in a temperate cropland of eastern China. Denaturing gradient electrophoresis (DGGE) fingerprinting analysis showed that the structure and composition of bacterial and fungi communities in the six fertilizer treatments varied at different levels. The Shannon index of bacterial and fungi communities displayed the highest value in the MB treatments and the lowest in the N treatment at the maize mature stage. Changes in soil microorganism community structure and diversity after different fertilizer treatments resulted in different microbial properties. Adding manure compost significantly increased the amount of cultivable microorganisms and microbial biomass, thus enhancing soil respiration and enzyme activities (p<0.01), whereas N treatment showed the opposite results (p<0.01). However, B and NB treatments minimally increased the amount of cultivable microorganisms and microbial biomass, with no obvious influence on community structure and soil enzymes. Our findings indicate that the application of manure compost plus bacterial fertilizers can immediately improve the microbial community structure and diversity of degraded cropland soils. PMID:25302996

Soil Science and Global Issues

NASA Astrophysics Data System (ADS)

Lal, Rattan

2015-04-01

Sustainable management of soil is integral to any rational approach to addressing global issues of the 21st century. A high quality soil is essential to: i) advancing food and nutritional security, ii) mitigating and adapting to climate change, iii) improving quality and renewability of water, iv) enriching biodiversity, v) producing biofuel feedstocks for reducing dependence on fossil fuel, and vi) providing cultural, aesthetical and recreational opportunities. Being the essence of all terrestrial life, soil functions and ecosystem services are essential to wellbeing of all species of plants and animals. Yet, soil resources are finite, unequally distributed geographically, and vulnerable to degradation by natural and anthropogenic perturbations. Nonetheless, soil has inherent resilience, and its ecosystem functions and services can be restored over time. However, soil resilience depends on several key soil properties including soil organic carbon (SOC) concentration and pool, plant-available water capacity (PWAC), nutrient reserves, effective rooting depth, texture and clay mineralogy, pH, cation exchange capacity (CEC) etc. There is a close inter-dependence among these properties. For example, SOC concentration strongly affects, PWAC, nutrient reserve, activity and species diversity of soil flora and fauna, CEC etc. Thus, judicious management of SOC concentration to maintain it above the threshold level (~1.5-2%) in the root zone is critical to sustaining essential functions and ecosystem services. Yet, soils of some agroecosystems (e.g., those managed by resources-poor farmers and small landholders in the tropics and sub-tropics) are severely depleted of their SOC reserves. Consequently. Agronomic productivity and wellbeing of people dependent on degraded soils is jeopardized. The ecosystem C pool of the terrestrial biosphere has been mined by extractive practices, the nature demands recarbonization of its biosphere for maintenance of its functions and resilience. Commemorating 2015 IYS is timely to create awareness among policy makers and general public that soil should never be taken for granted.

Do soil organisms affect aboveground litter decomposition in the semiarid Patagonian steppe, Argentina?

PubMed

Araujo, Patricia I; Yahdjian, Laura; Austin, Amy T

2012-01-01

Surface litter decomposition in arid and semiarid ecosystems is often faster than predicted by climatic parameters such as annual precipitation or evapotranspiration, or based on standard indices of litter quality such as lignin or nitrogen concentrations. Abiotic photodegradation has been demonstrated to be an important factor controlling aboveground litter decomposition in aridland ecosystems, but soil fauna, particularly macrofauna such as termites and ants, have also been identified as key players affecting litter mass loss in warm deserts. Our objective was to quantify the importance of soil organisms on surface litter decomposition in the Patagonian steppe in the absence of photodegradative effects, to establish the relative importance of soil organisms on rates of mass loss and nitrogen release. We estimated the relative contribution of soil fauna and microbes to litter decomposition of a dominant grass using litterboxes with variable mesh sizes that excluded groups of soil fauna based on size class (10, 2, and 0.01 mm), which were placed beneath shrub canopies. We also employed chemical repellents (naphthalene and fungicide). The exclusion of macro- and mesofauna had no effect on litter mass loss over 3 years (P = 0.36), as litter decomposition was similar in all soil fauna exclusions and naphthalene-treated litter. In contrast, reduction of fungal activity significantly inhibited litter decomposition (P < 0.001). Although soil fauna have been mentioned as a key control of litter decomposition in warm deserts, biogeographic legacies and temperature limitation may constrain the importance of these organisms in temperate aridlands, particularly in the southern hemisphere.

[Impact of land-use type changes on soil nitrification and ammonia-oxidizing bacterial community composition].

PubMed

Yang, Li-Lin; Mao, Ren-Zhao; Liu, Jun-Jie; Liu, Xiao-Jing

2011-11-01

A comparative study was conducted to determine nitrification potentials and ammonia-oxidizing bacterial (AOB) community composition in 0-20 cm soil depth in adjacent native forest,natural grassland, and cropland soils on the Tibetan Plateau, by incubation experiment and by denaturing gradient gel electrophoresis (DGGE) of 16S rDNA, respectively. Cropland has the highest nitrification potential and nitrate concentration among the three land-use types (LUT), approximately 9 folds and more than 11 folds than that of the forests and grasslands, respectively. NO3(-) -N accounted for 70%-90% of inorganic N in cropland soil, while NH4(+) -N was the main form of inorganic N in forest and grassland soils. Nitrification potentials and nitrate concentrations showed no significant difference between native forest and grassland soils. The native forest showed the lowest nitrification potentials and the lowest AOB diversity and community composition among the three LUT. Conversions from natural grasslands to croplands remarkably decreased the AOB diversity and composition, but croplands remain high similarity in AOB community composition compared with grasslands. The minimal and the lowest diversity of AOB in native forests directly resulted to the lowest nitrification potentials compared to natural grasslands and croplands. From the fact of the highest nitrification potentials and nitrate concentrations in croplands indicated that there were the most substantial AOB with higher activity and priority. The results provide evidence that changes of land-use type can affect both soil nitrogen internal cycling process, the diversity, community and activity of AOB, which further affect soil environment quality and the long-term sustainability of ecosystems.

Tree species, tree genotypes and tree genotypic diversity levels affect microbe-mediated soil ecosystem functions in a subtropical forest.

PubMed

Purahong, Witoon; Durka, Walter; Fischer, Markus; Dommert, Sven; Schöps, Ricardo; Buscot, François; Wubet, Tesfaye

2016-11-18

Tree species identity and tree genotypes contribute to the shaping of soil microbial communities. However, knowledge about how these two factors influence soil ecosystem functions is still lacking. Furthermore, in forest ecosystems tree genotypes co-occur and interact with each other, thus the effects of tree genotypic diversity on soil ecosystem functions merit attention. Here we investigated the effects of tree species, tree genotypes and genotypic diversity levels, alongside soil physicochemical properties, on the overall and specific soil enzyme activity patterns. Our results indicate that tree species identity, tree genotypes and genotypic diversity level have significant influences on overall and specific soil enzyme activity patterns. These three factors influence soil enzyme patterns partly through effects on soil physicochemical properties and substrate quality. Variance partitioning showed that tree species identity, genotypic diversity level, pH and water content all together explained ~30% variations in the overall patterns of soil enzymes. However, we also found that the responses of soil ecosystem functions to tree genotypes and genotypic diversity are complex, being dependent on tree species identity and controlled by multiple factors. Our study highlights the important of inter- and intra-specific variations in tree species in shaping soil ecosystem functions in a subtropical forest.

Tree species, tree genotypes and tree genotypic diversity levels affect microbe-mediated soil ecosystem functions in a subtropical forest

PubMed Central

Purahong, Witoon; Durka, Walter; Fischer, Markus; Dommert, Sven; Schöps, Ricardo; Buscot, François; Wubet, Tesfaye

2016-01-01

Tree species identity and tree genotypes contribute to the shaping of soil microbial communities. However, knowledge about how these two factors influence soil ecosystem functions is still lacking. Furthermore, in forest ecosystems tree genotypes co-occur and interact with each other, thus the effects of tree genotypic diversity on soil ecosystem functions merit attention. Here we investigated the effects of tree species, tree genotypes and genotypic diversity levels, alongside soil physicochemical properties, on the overall and specific soil enzyme activity patterns. Our results indicate that tree species identity, tree genotypes and genotypic diversity level have significant influences on overall and specific soil enzyme activity patterns. These three factors influence soil enzyme patterns partly through effects on soil physicochemical properties and substrate quality. Variance partitioning showed that tree species identity, genotypic diversity level, pH and water content all together explained ~30% variations in the overall patterns of soil enzymes. However, we also found that the responses of soil ecosystem functions to tree genotypes and genotypic diversity are complex, being dependent on tree species identity and controlled by multiple factors. Our study highlights the important of inter- and intra-specific variations in tree species in shaping soil ecosystem functions in a subtropical forest. PMID:27857198

Effect of long-term industrial waste effluent pollution on soil enzyme activities and bacterial community composition.

PubMed

Subrahmanyam, Gangavarapu; Shen, Ju-Pei; Liu, Yu-Rong; Archana, Gattupalli; Zhang, Li-Mei

2016-02-01

Although numerous studies have addressed the influence of exogenous pollutants on microorganisms, the effect of long-term industrial waste effluent (IWE) pollution on the activity and diversity of soil bacteria was still unclear. Three soil samples characterized as uncontaminated (R1), moderately contaminated (R2), and highly contaminated (R3) receiving mixed organic and heavy metal pollutants for more than 20 years through IWE were collected along the Mahi River basin, Gujarat, western India. Basal soil respiration and in situ enzyme activities indicated an apparent deleterious effect of IWE on microbial activity and soil function. Community composition profiling of soil bacteria using 16S rRNA gene amplification and denaturing gradient gel electrophoresis (DGGE) method indicated an apparent bacterial community shift in the IWE-affected soils. Cloning and sequencing of DGGE bands revealed that the dominated bacterial phyla in polluted soil were affiliated with Firmicutes, Acidobacteria, and Actinobacteria, indicating that these bacterial phyla may have a high tolerance to pollutants. We suggested that specific bacterial phyla along with soil enzyme activities could be used as relevant biological indicators for long-term pollution assessment on soil quality. Graphical Abstract Bacterial community profiling and soil enzyme activities in long-term industrial waste effluent polluted soils.

Yield and Water Quality Impacts of Field-Scale Integration of Willow into a Continuous Corn Rotation System.

PubMed

Zumpf, Colleen; Ssegane, Herbert; Negri, Maria Cristina; Campbell, Patty; Cacho, Julian

2017-07-01

Agricultural landscape design has gained recognition by the international environmental and development community as a strategy to address multiple goals in land, water, and ecosystem service management; however, field research is needed to quantify impacts on specific local environments. The production of bioenergy crops in specific landscape positions within a grain-crop field can serve the dual purpose of producing cellulosic biomass (nutrient recovery) while also providing regulating ecosystem services to improve water quality (nutrient reduction). The effectiveness of such a landscape design was evaluated by the strategic placement of a 0.8-ha short-rotation shrub willow ( Seemen) bioenergy buffer along marginal soils in a 6.5-ha corn ( L.) field in a 6-yr field study in central Illinois. The impact of willow integration on water quality (soil water, shallow groundwater leaching, and crop nutrient uptake) and quantity (soil moisture and transpiration) was monitored in comparison with corn in the willow's first cycle of growth. Willows significantly reduced nitrate leachate in shallow subsurface water by 88% while maintaining adequate nutrient and water usage. Results suggest that willows offer an efficient nutrient-reduction strategy and may provide additional ecosystem services and benefits, including enhanced soil health. However, low values for calculated willow biomass will need to be readdressed in the future as harvest data become available to understand contributing factors that affected productivity beyond nutrient availability. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Biological indices of soil quality: an ecosystem case study of their use

Treesearch

Jennifer D. Knoepp; David C. Coleman; D.A. Crossley; James S. Clark

2000-01-01

Soil quality indices can help ensure that site productivity and soil function are maintained. Biological indices yield evidence of how a soil functions and interacts with the plants, animals, and climate that comprise an ecosystem. Soil scientists can identify and quantify both chemical and biological soil-quality indicators for ecosystems with a single main function,...

Human brains found in a fire-affected 4000-years old Bronze Age tumulus layer rich in soil alkalines and boron in Kutahya, Western Anatolia.

PubMed

Altinoz, M A; Ince, B; Sav, A; Dincer, A; Cengiz, S; Mercan, S; Yazici, Z; Bilgen, M N

2014-02-01

Undecomposed human bodies and organs always attracted interest in terms of understanding biological tissue stability and immortality. Amongst these, cases of natural mummification found in glaciers, bog sediments and deserts caused even more attention. In 2010, an archeological excavation of a Bronze Age layer in a tumulus near the Western Anatolia city Kütahya revealed fire affected regions with burnt human skeletons and charred wooden objects. Inside of the cracked skulls, undecomposed brains were discernible. To analyze the burial taphonomy of the rare phenomenon of brain preservation, we analyzed brains, bone, teeth and surrounding soils elements using Inductively Coupled Plasma-Mass Spectrometer (ICP-MS). Adipocere formation or saponification of postmortem tissue fat requires high levels of alkalinity and especially potassium. Indeed, ICP-MS analysis of the brain, teeth and bone and also of the surrounding soil revealed high levels of potassium, magnesium, aluminum and boron, which are compatible with the famous role of Kütahya in tile production with its soil containing high level of alkalines and tile-glazing boron. Fatty acid chromatography revealed simultaneous saturation of fats and protection of fragile unsaturated fatty acids consistent with soil-presence of both pro-oxidant and anti-oxidant trace metals. Computerized tomography revealed protection of diencephalic, metencephalic and occipital tissue in one of the best-preserved specimens. Boron was previously found as an intentional preservative of Tutankhamen and Deir el Bahari mummies. Here, in natural soil with its insect-repellant, anti-bacterial and fire-resistance qualities it may be a factor to preserve heat-affected brains as almost bioporcellain specimens. Copyright © 2013 Elsevier GmbH. All rights reserved.

[Evolvement of soil quality in salt marshes and reclaimed farmlands in Yancheng coastal wetland].

PubMed

Mao, Zhi-Gang; Gu, Xiao-Hong; Liu, Jin-E; Ren, Li-Juan; Wang, Guo-Xiang

2010-08-01

Through vegetation investigation and soil analysis, this paper studied the evolvement of soil quality during natural vegetation succession and after farmland reclamation in the Yancheng coastal wetland of Jiangsu Province. Along with the process of vegetation succession, the soil physical, chemical, and biological properties in the wetland improved, which was manifested in the improvement of soil physical properties and the increase of soil nutrient contents, microbial biomass, and enzyme activities. Different vegetation type induced the differences in soil properties. Comparing with those in salt marshes, the soil salt content in reclaimed farmlands decreased to 0.01 - 0.04%, the soil microbial biomass and enzyme activities increased, and the soil quality improved obviously. The soil quality index (SQI) in the wetland was in the order of mudflat (0.194) < Suaeda salsa flat (0.233) < Imperata cylindrica flat (0.278) < Spartina alterniflora flat (0.446) < maize field (0.532) < cotton field (0.674) < soybean field (0.826), suggesting that positive vegetation succession would be an effective approach in improving soil quality.

Soil quality indicator responses to row crop, grazed pasture, and agroforestry buffer management

USDA-ARS?s Scientific Manuscript database

Incorporation of trees and establishment of grass buffers within agroecosystems are management practices shown to enhance soil quality. Soil enzyme activities and water stable aggregates (WSA) have been identified as sensitive soil quality indicators to evaluate early responses to soil management. ...

Modification of pomological characteristics and flavour components of fruits and virgin olive oil following wastewater irrigation and soil tillage.

PubMed

Tekaya, Meriem; Chehab, Hechmi; Flamini, Guido; Gharbi, Ines; Mahjoub, Zoubeir; Laamari, Salwa; Chihaoui, Badreddine; Boujnah, Dalenda; Hammami, Mohamed; Mechri, Beligh

2018-06-01

The experiment was carried out on olive trees cv. Chemlali, during two successive years (2013/2014). Two irrigation treatments (IT: Trees irrigated with wastewater; TRC: Trees grown under rainfed condition) were combined with two tillage practices (TTS: Trees grown in tilled soil; TNTS: Trees grown in non-tilled soil). The results of the study showed that wastewater irrigation combined with soil tillage improved the pomological characteristics of olive fruits. The tree yield increase was substantial for IT and TTS. However, most of the identified phenolic compounds, especially oleuropein, mainly accumulated in olive fruits of the TC block (TNTS + TRC), suggesting a marked improvement in the nutritional value of these fruits. Moreover, fruits of TNTS had high contents of sugar compounds, required for the synthesis of the fruit storage material. The study also showed that the agronomic practices affected the amounts of some aromatic compounds responsible for the distinctive flavour notes of olive oil. Agronomic practices may affect considerably the commercial and nutritional values and the sensorial quality of the commodities. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Soil indigenous knowledge in North Central Namibia

NASA Astrophysics Data System (ADS)

Prudat, Brice; Bloemertz, Lena; Kuhn, Nikolaus J.

2016-04-01

Mapping and classifying soils is part of an important learning process to improve soil management practices, soil quality and increase productivity. In order to assess soil quality improvement related to an ongoing land reform in North-Central Namibia, the characteristics that determine soil quality in the local land use context were determined in this study. To do so, we collated the indigenous soil knowledge in North-Central Namibia where the Ovakwanyama cultivate pearl millet for centuries. Local soil groups are defined mostly based on their productivity potential, which varies depending on the rainfall pattern. The morphological criteria used by the farmers to differentiate the soil groups (colour, consistence) were supported by a conventional analysis of soil physical and chemical properties. Now, they can be used to develop a soil quality assessment toolbox adapted to the regional use. The characteristics of the tool box do not directly indicate soil quality, but refer to local soils groups. The quality of these groups is relatively homogenous at the local scale. Our results show that understanding of indigenous soil knowledge has great potential to improve soil quality assessment with regards to land use. The integration of this knowledge with the conventional soil analysis improves the local meaning of such a "scientific" assessment and thus facilitates dialog between farmers and agronomists, but also scientists working in different regions of the world, but in similar conditions. Overall, the integration of indigenous knowledge in international classification systems (e.g. WRB) as attempted in this study has thus a major potential to improve soil mapping in the local context.

The dissolved organic matter as a potential soil quality indicator in arable soils of Hungary.

PubMed

Filep, Tibor; Draskovits, Eszter; Szabó, József; Koós, Sándor; László, Péter; Szalai, Zoltán

2015-07-01

Although several authors have suggested that the labile fraction of soils could be a potential soil quality indicator, the possibilities and limitations of using the dissolved organic matter (DOM) fraction for this purpose have not yet been investigated. The objective of this study was to evaluate the hypothesis that DOM is an adequate indicator of soil quality. To test this, the soil quality indices (SQI) of 190 arable soils from a Hungarian dataset were estimated, and these values were compared to DOM parameters (DOC and SUVA254). A clear difference in soil quality was found between the soil types, with low soil quality for arenosols (average SQI 0.5) and significantly higher values for gleysols, vertisols, regosols, solonetzes and chernozems. The SQI-DOC relationship could be described by non-linear regression, while a linear connection was observed between SQI and SUVA. The regression equations obtained for the dataset showed only one relatively weak significant correlation between the variables, for DOC (R (2) = 0.157(***); n = 190), while non-significant relationships were found for the DOC and SUVA254 values. However, an envelope curve operated with the datasets showed the robust potential of DOC to indicate soil quality changes, with a high R (2) value for the envelope curve regression equation. The limitations to using the DOM fraction of soils as a quality indicator are due to the contradictory processes which take place in soils in many cases.

The Influence of Hydrophobicity, Inorganic Amendments and Surfactants on Turfgrass Establishment, Growth and Quality in Constructed Root Zone Mixes

NASA Astrophysics Data System (ADS)

McMillan, Mica Franklin

Soil water repellency (SWR) negatively affects turfgrass growth and quality and impedes uniform distribution of water, particularly in sand-based rootzones. Surfactants and soil amendments such as calcined clay are two approaches to improving soil hydrological properties affected by SWR. However, studying SWR in the field is difficult due to the extreme spatial variability in the soil profile. An objective of this dissertation was to assess two methods to impart SWR on sand and examine SWR amelioration strategies using these procedures under a plant environment and deficit irrigation. To determine effectiveness of artificial hydrophobicity, two methods produced severely hydrophobic substrates: stearic acid sand (HSS) and sand:peat (90:10 sand:peat v/v)(HSP). Greenhouse studies compared the effects of substrates HSS, HSP, 100% sand (SAND), sand:peat (90:10 v/v) (SP), sand:calcined clay (90:10 v/v) (CC) and naturally water repellent sand (NWRS) on bermudagrass [Cynodon dactylon (L.) Pers. x C. transvaalensis Burtt Davy] establishment and growth. Results indicate that HSS and HSP were not toxic to turfgrass but initially, hindered bermudagrass growth. At trials end, SWR had declined in both soils. A second greenhouse study assessed surfactant chemistry on substrates. After three dry downs, surfactants generally improved turfgrass quality in SAND and CC but had no significant effect in HSP and SP. Water drop penetration tests deemed CC and SAND wettable and HSP and SP nonwettable. Contact angle analysis found CC and SAND to be subcritically water repellent while HSP and SP were water repellent. Both HSP and HSS could be used to evaluate the influence of SWR on plant growth. However, both methods have disadvantages. CC remained wettable after several dry downs. In another greenhouse study, perennial ryegrass (Lolium perenne) seeds coated with 10% w/w alkyl-terminated block copolymer surfactant seed coating (SC) were evaluated as an amelioration strategy. Seed treated with surfactant yielded similar or greater percent coverage, shoot growth, root weight and increased volumetric water in the majority of substrates when compared to substrates sown with untreated seed. Coating seeds with surfactant may be used as a method to improve seed germination, establishment and enhance soil moisture, particularly under deficit irrigation.

Soil quality parameters for row-crop and grazed pasture systems with agroforestry buffers

USDA-ARS?s Scientific Manuscript database

Incorporation of trees and establishment of buffers are practices that can improve soil quality. Soil enzyme activities and water stable aggregates are sensitive indices for assessing soil quality by detecting early changes in soil management. However, studies comparing grazed pasture and row crop...

Flocculation of organic carbon from headwaters to estuary - the impact of soil erosion, water quality and land use on carbon transformation processes in eight streams draining Exmoor, UK

NASA Astrophysics Data System (ADS)

Snoalv, J.; Groeneveld, M.; Quine, T. A.; Tranvik, L.

2017-12-01

Flocculation of dissolved organic carbon (DOC) in streams and rivers is a process that contributes to the pool of particulate organic carbon (POC) in the aquatic system. In low-energy waters the increased sedimentation rates of this higher-density fraction of organic carbon (OC) makes POC important in allocating organic carbon into limnic storage, which subsequently influences emissions of greenhouse gases from the continental environment to the atmosphere. Allochthonous OC, derived from the terrestrial environment by soil erosion and litterfall, import both mineral aggregate-bound and free OC into freshwaters, which comprise carbon species of different quality and recalcitrance than autochthonous in-stream produced OC, such as from biofilms, aquatic plants and algae. Increased soil erosion due to land use change (e.g. agriculture, deforestation etc.) influences the input of allochthonous OC, which can lead to increased POC formation and sedimentation of terrestrial OC at flocculation boundaries in the landscape, i.e. where coagulation and flocculation processes are prone to occur in the water column. This study investigates the seasonal variation in POC content and flocculation capacity with respect to water quality (elemental composition) in eight river systems (four agricultural and four wooded streams) with headwaters in Exmoor, UK, that drain managed and non-managed land into Bristol Channel. Through flocculation experiments the samples were allowed to flocculate by treatments with added clay and salt standards that simulate the flocculation processes by 1) increased input of sediment into streams, and 2) saline mixing at the estuarine boundary, in order to quantify floc production and investigate POC quality by each process respectively. The results show how floc production, carbon quality and incorporation (e.g. complexation) of metals and rare earth elements (REE) in produced POC and remaining DOC in solution vary in water samples over the season and how these are related to different flocculation processes and affected by land use. This study improves our understanding on OC flocculation dynamics on a local catchment scale and how POC fate is affected by changed water quality in streams perturbed by land use change.

Carbon and nitrogen mineralization and enzyme activities in soil aggregate-size classes: Effects of biochar, oyster shells, and polymers.

PubMed

Awad, Yasser Mahmoud; Lee, Sang Soo; Kim, Ki-Hyun; Ok, Yong Sik; Kuzyakov, Yakov

2018-05-01

Biochar (BC) and polymers are cost-effective additives for soil quality improvement and long-term sustainability. The additional use of the oyster shells (OS) powder in BC- or polymer-treated soils is recommended as a nutrient source, to enhance aggregation and to increase enzyme activities. The effects of soil treatments (i.e., BC (5 Mg ha -1 ) and polymers (biopolymer at 0.4 Mg ha -1 or polyacrylamide at 0.4 Mg ha -1 ) with or without the OS (1%)) on the short-term changes were evaluated based on a 30-day incubation experiment with respect to several variables (e.g., CO 2 release, NH 4 + and NO 3 - concentrations, aggregate-size classes, and enzyme activities in an agricultural Luvisol). The BC and BP with the addition of OS increased the portion of microaggregates (<0.25 mm) relative to the control soil without any additions, while PAM alone increased the portion of large macroaggregates (1-2 mm). Concentrations of NO 3 - also increased in soils treated with OS, OS + BC, and OS + BP as result of the increased chitinase and leucine aminopeptidase activities. The BC and BP when treated with the additional OS had significant short-term impacts on N mineralization without affecting C mineralization in soil. Consequently, the combination of BC or BP with OS was seen to accelerate N turnover without affecting C turnover (and related C losses) from soil. As such, the addition of these additives contributed considerably to the improvement of soil fertility and C sequestration. Copyright © 2018 Elsevier Ltd. All rights reserved.

Dynamics of Soil Bacterial Communities in Response to Repeated Application of Manure Containing Sulfadiazine

PubMed Central

Ding, Guo-Chun; Radl, Viviane; Schloter-Hai, Brigitte; Jechalke, Sven; Heuer, Holger; Smalla, Kornelia; Schloter, Michael

2014-01-01

Large amounts of manure have been applied to arable soils as fertilizer worldwide. Manure is often contaminated with veterinary antibiotics which enter the soil together with antibiotic resistant bacteria. However, little information is available regarding the main responders of bacterial communities in soil affected by repeated inputs of antibiotics via manure. In this study, a microcosm experiment was performed with two concentrations of the antibiotic sulfadiazine (SDZ) which were applied together with manure at three different time points over a period of 133 days. Samples were taken 3 and 60 days after each manure application. The effects of SDZ on soil bacterial communities were explored by barcoded pyrosequencing of 16S rRNA gene fragments amplified from total community DNA. Samples with high concentration of SDZ were analyzed on day 193 only. Repeated inputs of SDZ, especially at a high concentration, caused pronounced changes in bacterial community compositions. By comparison with the initial soil, we could observe an increase of the disturbance and a decrease of the stability of soil bacterial communities as a result of SDZ manure application compared to the manure treatment without SDZ. The number of taxa significantly affected by the presence of SDZ increased with the times of manure application and was highest during the treatment with high SDZ-concentration. Numerous taxa, known to harbor also human pathogens, such as Devosia, Shinella, Stenotrophomonas, Clostridium, Peptostreptococcus, Leifsonia, Gemmatimonas, were enriched in the soil when SDZ was present while the abundance of bacteria which typically contribute to high soil quality belonging to the genera Pseudomonas and Lysobacter, Hydrogenophaga, and Adhaeribacter decreased in response to the repeated application of manure and SDZ. PMID:24671113

Dynamics of soil bacterial communities in response to repeated application of manure containing sulfadiazine.

PubMed

Ding, Guo-Chun; Radl, Viviane; Schloter-Hai, Brigitte; Jechalke, Sven; Heuer, Holger; Smalla, Kornelia; Schloter, Michael

2014-01-01

Large amounts of manure have been applied to arable soils as fertilizer worldwide. Manure is often contaminated with veterinary antibiotics which enter the soil together with antibiotic resistant bacteria. However, little information is available regarding the main responders of bacterial communities in soil affected by repeated inputs of antibiotics via manure. In this study, a microcosm experiment was performed with two concentrations of the antibiotic sulfadiazine (SDZ) which were applied together with manure at three different time points over a period of 133 days. Samples were taken 3 and 60 days after each manure application. The effects of SDZ on soil bacterial communities were explored by barcoded pyrosequencing of 16S rRNA gene fragments amplified from total community DNA. Samples with high concentration of SDZ were analyzed on day 193 only. Repeated inputs of SDZ, especially at a high concentration, caused pronounced changes in bacterial community compositions. By comparison with the initial soil, we could observe an increase of the disturbance and a decrease of the stability of soil bacterial communities as a result of SDZ manure application compared to the manure treatment without SDZ. The number of taxa significantly affected by the presence of SDZ increased with the times of manure application and was highest during the treatment with high SDZ-concentration. Numerous taxa, known to harbor also human pathogens, such as Devosia, Shinella, Stenotrophomonas, Clostridium, Peptostreptococcus, Leifsonia, Gemmatimonas, were enriched in the soil when SDZ was present while the abundance of bacteria which typically contribute to high soil quality belonging to the genera Pseudomonas and Lysobacter, Hydrogenophaga, and Adhaeribacter decreased in response to the repeated application of manure and SDZ.

Effects of Combined Application of Biogas Slurry and Chemical Fertilizer on Soil Aggregation and C/N Distribution in an Ultisol.

PubMed

Zheng, Xuebo; Fan, Jianbo; Xu, Lei; Zhou, Jing

2017-01-01

Unreasonable use of chemical fertilizer (CF) on agricultural soil leads to massive losses of soil organic carbon (SOC) and total nitrogen (TN) in tropical and subtropical areas, where soil conditions are unfavorable for aggregate formation. This study evaluated the effects of combined application of biogas slurry (BS) plus CF on soil aggregation and aggregate-associated C/N concentration and storage in an Ultisol. Six treatments included: no fertilizer (T1), CF only (T2), partial (15% (T3), 30% (T4) and 45% (T5)) substitution of TN with BS and BS only (T6). Soil mechanical-stable aggregates (MSAs) formation and stability as well as MSAs-associated C/N concentration and storage were observed in different aggregate sizes (>5, 5-2, 2-1, 1.0-0.5, 0.50-0.25 and <0.25 mm). The proportion of MSAs >5 mm significantly increased with BS substitution (T5), while the proportions of MSAs 1.0-0.5 mm, MSAs 0.50-0.25 mm and MSAs <0.25 mm significantly decreased. Both mean weight diameter and geometric mean diameter were highest in T5, which improved soil aggregation stability as well as resulted in significantly higher SOC and TN concentrations and storage in MSAs >0.5 mm that constituted 72-82% of MSAs. Stepwise regression analysis showed that MSAs >5 mm, SOC in MSAs >5 mm and TN in MSAs >5 mm were the dominant variables affecting aggregate stability. Meanwhile SOC in MSAs <0.25 mm and TN in MSAs 2-1 mm were independent variables affecting SOC and TN concentrations in bulk soils. Therefore, certain rate of combined application of BS plus CF is an effective, eco-friendly way to improve soil quality in an Ultisol.

Plant Diversity Surpasses Plant Functional Groups and Plant Productivity as Driver of Soil Biota in the Long Term

PubMed Central

Eisenhauer, Nico; Milcu, Alexandru; Sabais, Alexander C. W.; Bessler, Holger; Brenner, Johanna; Engels, Christof; Klarner, Bernhard; Maraun, Mark; Partsch, Stephan; Roscher, Christiane; Schonert, Felix; Temperton, Vicky M.; Thomisch, Karolin; Weigelt, Alexandra; Weisser, Wolfgang W.; Scheu, Stefan

2011-01-01

Background One of the most significant consequences of contemporary global change is the rapid decline of biodiversity in many ecosystems. Knowledge of the consequences of biodiversity loss in terrestrial ecosystems is largely restricted to single ecosystem functions. Impacts of key plant functional groups on soil biota are considered to be more important than those of plant diversity; however, current knowledge mainly relies on short-term experiments. Methodology/Principal Findings We studied changes in the impacts of plant diversity and presence of key functional groups on soil biota by investigating the performance of soil microorganisms and soil fauna two, four and six years after the establishment of model grasslands. The results indicate that temporal changes of plant community effects depend on the trophic affiliation of soil animals: plant diversity effects on decomposers only occurred after six years, changed little in herbivores, but occurred in predators after two years. The results suggest that plant diversity, in terms of species and functional group richness, is the most important plant community property affecting soil biota, exceeding the relevance of plant above- and belowground productivity and the presence of key plant functional groups, i.e. grasses and legumes, with the relevance of the latter decreasing in time. Conclusions/Significance Plant diversity effects on biota are not only due to the presence of key plant functional groups or plant productivity highlighting the importance of diverse and high-quality plant derived resources, and supporting the validity of the singular hypothesis for soil biota. Our results demonstrate that in the long term plant diversity essentially drives the performance of soil biota questioning the paradigm that belowground communities are not affected by plant diversity and reinforcing the importance of biodiversity for ecosystem functioning. PMID:21249208

BiodivERsA project VineDivers: Analysing interlinkages between soil biota and biodiversity-based ecosystem services in vineyards across Europe

NASA Astrophysics Data System (ADS)

Zaller, Johann G.; Winter, Silvia; Strauss, Peter; Querner, Pascal; Kriechbaum, Monika; Pachinger, Bärbel; Gómez, José A.; Campos, Mercedes; Landa, Blanca; Popescu, Daniela; Comsa, Maria; Iliescu, Maria; Tomoiaga, Liliana; Bunea, Claudiu-Ioan; Hoble, Adela; Marghitas, Liviu; Rusu, Teodor; Lora, Ángel; Guzmán, Gema; Bergmann, Holger

2015-04-01

Essential ecosystem services provided by viticultural landscapes result from diverse communities of above- and belowground organisms and their interactions. For centuries traditional viticulture was part of a multifunctional agricultural system including low-input grasslands and fruit trees resulting in a high functional biodiversity. However, in the last decades intensification and mechanisation of vineyard management caused a separation of production and conservation areas. As a result of management intensification including frequent tilling and/or use of pesticides several ecosystem services are affected leading to high rates of soil erosion, degradation of soil structure and fertility, contamination of groundwater and high levels of agricultural inputs. In this transdisciplinary BiodivERsA project we will examine to what extent differently intensive managed vineyards affect the activity and diversity of soil biota (e.g. earthworms, collembola, soil microorganisms) and how this feed back on aboveground biodiversity (e.g. weeds, pollinators). We will also investigate ecosystem services associated with soil faunal activity and biodiversity such as soil structure, the formation of stable soil aggregates, water infiltration, soil erosion as well as grape quality. These effects will become increasingly important as more extreme precipitation events are predicted with climate change. The socio-economic part of the project will investigate the role of diversely structured, species-rich viticultural landscapes as a cultural heritage providing aesthetic values for human well-being and recreation. The project objectives will be analysed at plot, field (vineyard) and landscape scales in vineyards located in Spain, France, Romania and Austria. A detailed engagement and dissemination plan for stakeholder at the different governance levels will accompany scientific research and will contribute to the implementation of best-practice recommendations for policy and farmers.

Degradation and resilience of soils

PubMed Central

Lal, R.

1997-01-01

Debate on global soil degradation, its extent and agronomic impact, can only be resolved through understanding of the processes and factors leading to establishment of the cause-effect relationships for major soils, ecoregions, and land uses. Systematic evaluation through long-term experimentation is needed for establishing quantitative criteria of (i) soil quality in relation to specific functions; (ii) soil degradation in relation to critical limits of key soil properties and processes; and (iii) soil resilience in relation to the ease of restoration through judicious management and discriminate use of essential input. Quantitative assessment of soil degradation can be obtained by evaluating its impact on productivity for different land uses and management systems. Interdisciplinary research is needed to quantify soil degradation effects on decrease in productivity, reduction in biomass, and decline in environment quality throught pollution and eutrophication of natural waters and emission of radiatively-active gases from terrestrial ecosystems to the atmosphere. Data from long-term field experiments in principal ecoregions are specifically needed to (i) establish relationships between soil quality versus soil degradation and soil quality versus soil resilience; (ii) identify indicators of soil quality and soil resilience; and (iii) establish critical limits of important properties for soil degradation and soil resilience. There is a need to develop and standardize techniques for measuring soil resilience.

Manure-amended soil characteristics affecting the survival of E. coli O157:H7 in 36 Dutch soils.

PubMed

Franz, Eelco; Semenov, Alexander V; Termorshuizen, Aad J; de Vos, O J; Bokhorst, Jan G; van Bruggen, Ariena H C

2008-02-01

The recent increase in foodborne disease associated with the consumption of fresh vegetables stresses the importance of the development of intervention strategies that minimize the risk of preharvest contamination. To identify risk factors for Escherichia coli O157:H7 persistence in soil, we studied the survival of a Shiga-toxin-deficient mutant in a set of 36 Dutch arable manure-amended soils (organic/conventional, sand/loam) and measured an array of biotic and abiotic manure-amended soil characteristics. The Weibull model, which is the cumulative form of the underlying distribution of individual inactivation kinetics, proved to be a suitable model for describing the decline of E. coli O157:H7. The survival curves generally showed a concave curvature, indicating changes in biological stress over time. The calculated time to reach the detection limit ttd ranged from 54 to 105 days, and the variability followed a logistic distribution. Due to large variation among soils of each management type, no differences were observed between organic and conventional soils. Although the initial decline was faster in sandy soils, no significant differences were observed in ttd between both sandy and loamy soils. With sandy, loamy and conventional soils, the variation in ttd was best explained by the level of dissolved organic carbon per unit biomass carbon DOC/biomC, with prolonged survival at increasing DOC/biomC. With organic soils, the variation in ttd was best explained by the level of dissolved organic nitrogen (positive relation) and the microbial species diversity as determined by denaturing gradient gel electrophoresis (negative relation). Survival increased with a field history of low-quality manure (artificial fertilizer and slurry) compared with high-quality manure application (farmyard manure and compost). We conclude that E. coli O157:H7 populations decline faster under more oligotrophic soil conditions, which can be achieved by the use of organic fertilizer with a relatively high C/N ratio and consequently a relatively low rate of nutrient release.

Can homogeneous harvest zones magnify the terroir effect of every vintage? The three year project VignaCRU in Chianti D.O.C.G. (Tuscany, Italy)

NASA Astrophysics Data System (ADS)

Priori, Simone; Bianconi, Nadia; Valboa, Giuseppe; Mocali, Stefano; Pellegrini, Sergio; Leprini, Marco; Perria, Rita; Storchi, Paolo; Ciambotti, Aldo; Dell'Oro, Valentina; Costantini, Edoardo A. C.

2015-04-01

Grape composition, which affects the wine sensory qualities, depends on vine features (rootstock, scion, vine health) and vineyard management as much as environmental factors. Mapping soil at the vineyard scale, in particular, helps in optimizing the terroir expression of the wine. The terroir effect however varies year by year, depending on the interaction of several factors, such as climate and soil. Aim of this research work was to set up a methodology to delineate homogeneous harvest zones (HZ) in the vineyard and to evaluate the vintage effect in them. Four terroir macro-units suitable for premium Sangiovese wine, which is the main cultivar of Chianti D.O.C.G., were selected within a wide farm of Chianti Classico district (Siena, Central Italy). The selected macro-units are representative of the most common and suitable viticultural environments of the Chianti Classico D.O.C.G. and include: 1) hills of high altitude (450-500 m a.s.l.) on feldspathic sandstones, with shallow sandy soils; 2) hills of high altitude (400-500 m a.s.l.) on calcareous flysches, with stony, clayey and calcareous soils; 3) hills of moderate altitude (250-350 m a.s.l.) on Pliocene sandy marine deposits; 4) hills and fluvial terraces of moderate altitude (200-300 m a.s.l., 50-100 m above the present river valley) on ancient fluvial deposits. Each terroir macro-unit was surveyed by soil proximal sensing, to define two homogeneous zones (HZs) in terms of soil physics and hydrology. The proximal sensors used to map the HZs were: i) γ-ray spectrometer, to map the variability of soil surface in terms of parent material, texture and stoniness; ii) electromagnetic induction sensor (EMI) to determine the spatial variability of texture and soil moisture in the sub-surface horizons. Thus, the soil moisture of each HZ was monitored during spring shoot growth (beginning of April), berries veraison (end of July-beginning of August) and final ripening phase before harvest (September). Three representative plots of 10 grapevines each were selected within each HZs to monitor: i) grapevine root development; ii) vine physiology and water stress; iii) grape yield and quality. Moreover, the grapes of each HZs were harvested and vinified separately. After three vintages ('12, '13, and '14) the main results are: i) terroir macro-units differentiated the grape and wine peculiarities every vintage; ii) The delineation of HZs within each macro-units, intensified the effect of terroir on wine quality only in the warmest and driest summer '12, whereas the effects under more humid summers, like in '13 and '14, were smaller; iii) the sandy soils on feldspathic sandstones and marine sands increased the quality of the wines only in the warm-dry vintage ('12), whereas the wine quality decreased in humid summers ('13-'14), because of lacking of suitable water stress; iv) the grapevines in the terroir characterized by stony and clayey soils, showed light water stress also in wetter summers ('13-'14) and the wines produced in this terroir showed the highest quality and the greatest stability in typicality during the years. Concluding, the results of our work seem to indicate that the differentiation of HZs within a suitable macro-terroir can be fruitful only in specific vintages, when the soil hydrology plays a major role on the wine quality and typicality.

The influence of farmland pollution on the quality and safety of agricultural products

NASA Astrophysics Data System (ADS)

Ma, Z. L.; Li, L. Y.; Ye, C.; Lin, X. Y.; B, C.; Wei

2018-02-01

The quality and safety of agricultural products is not only a major livelihood issues for people’s health, but also the main barriers to international trade of agricultural products nowadays. The soil is the foundation to the production of agricultural products and the guarantee of agricultural development. The farmland soil quality is directly related to the quality and safety of agricultural products. Our country’s soil has been polluted by a series of pollution, Such as the excessive discharge of industrial wastes, the encroachment of household waste, and the unreasonable use of pesticides and fertilizers. Soil degradation is a serious threat to the quality and safety of agricultural products, so eliminating soil degradation is the fundamental way out for quality and safety of agricultural products. By analyzing problems of the quality and safety of agricultural products in our country, and exploring the farmland soil influence on the quality and safety of agricultural products. This article provides a reference for improving the control level of quality and safety of agricultural products and the farmland soil quality.

Crop, tillage, and landscape effects on near-surface soil quality indices in Indiana

USDA-ARS?s Scientific Manuscript database

Soil quality is considered a link between land management and the quality of adjacent water bodies. We conducted a soil quality assessment within the Cedar Creek Watershed, a part of the larger St. Joseph River Watershed that drains into the Western Lake Erie Basin in northwestern Indiana. The Soil ...

Impact of diverse soil microbial communities on crop residues decomposition

NASA Astrophysics Data System (ADS)

Mrad, Fida; Bennegadi-Laurent, Nadia; Ailhas, Jérôme; Leblanc, Nathalie; Trinsoutrot-Gattin, Isabelle; Laval, Karine; Gattin, Richard

2017-04-01

Soils provide many basic ecosystem services for our society and most of these services are carried out by the soil communities, thus influencing soils quality. Soil organic matter (SOM) can be considered as one of the most important soil quality indices for it plays a determinant role in many physical, chemical and biological processes, such as soil structure and erosion resistance, cation exchange capacity, nutrient cycling and biological activity (Andrews et al., 2004). Since a long time, exogenous organic inputs are largely used for improving agricultural soils, affecting highly soil fertility and productivity. The use of organic amendments such as crop residues influences the soil microbial populations' diversity and abundance. In the meantime, soil microbial communities play a major role in the organic matter degradation, and the effect of different microbial communities on the decomposition of crop residues is not well documented. In this context, studying the impact of crop residues on soil microbial ecology and the processes controlling the fate of plant residues in different management practices is essential for understanding the long-term environmental and agronomic effects on soil and organic matters. Our purpose in the present work was to investigate the decomposition by two contrasting microbial communities of three crop residues, and compare the effect of different residues amendments on the abundance and function of each soil microbial communities. Among the main crops which produce large amounts of residues, we focused on three different plants: wheat (Triticum aestivum L.), rape (Brassica napus) and sunflower (Helianthus annuus). The residues degradation in two soils of different management practices and the microbial activity were evaluated by: microbial abundance (microbial carbon, culturable bacteria, total DNA, qPCR), in combination with functional indicators (enzymatic assays and Biolog substrate utilization), kinetics of C and N mineralization, and chemical measures. Physicochemical composition of crop residues was assessed by Fourier transform infrared spectroscopy FTIR technique at 0 and 83 days. The experiment was conducted in microcosms over 83 days for the biological measurements and 175 days for the C mineralization. The first results showed variations in the C & N rates, and the microbial abundances and functions over time, with a peak at 5 days and a decrease at 83 days for most of the measurements. The soil microbial communities' composition (different management practices) highly impacted the crop residues decomposition. The biochemical composition of crop residues influenced less the microbial communities of each soil. Further studies on the valorization of these residues into agro materials will be carried out. References: Andrews SS., Karlen DL., and Cambardella CA. (2004) The soil management assessment framework: a quantitative soil quality evaluation method. Soil Science Society of America, 68: 1945-1962

12 CFR Appendix A to Part 1010 - Standard and Model Forms and Clauses

Code of Federal Regulations, 2013 CFR

2013-01-01

....114 Subdivision Characteristics and Climate 1010.115 (a) General Topography (b) Water Coverage (c) Drainage and Fill (d) Flood Plain (e) Flooding and Soil Erosion (f) Nuisances (g) Hazards (h) Climate (i... of the land. Changes in plant and animal life, air and water quality and noise levels may affect your...

12 CFR Appendix A to Part 1010 - Standard and Model Forms and Clauses

Code of Federal Regulations, 2012 CFR

2012-01-01

....114 Subdivision Characteristics and Climate 1010.115 (a) General Topography (b) Water Coverage (c) Drainage and Fill (d) Flood Plain (e) Flooding and Soil Erosion (f) Nuisances (g) Hazards (h) Climate (i... of the land. Changes in plant and animal life, air and water quality and noise levels may affect your...

12 CFR Appendix A to Part 1010 - Standard and Model Forms and Clauses

Code of Federal Regulations, 2014 CFR

2014-01-01

....114 Subdivision Characteristics and Climate 1010.115 (a) General Topography (b) Water Coverage (c) Drainage and Fill (d) Flood Plain (e) Flooding and Soil Erosion (f) Nuisances (g) Hazards (h) Climate (i... of the land. Changes in plant and animal life, air and water quality and noise levels may affect your...

Positive effects of afforestation efforts on the health of urban soils

Treesearch

Emily E. Oldfield; Alexander J. Felson; Stephen A. Wood; Richard A. Hallett; Michael S. Strickland; Mark A. Bradford

2014-01-01

Large-scale tree planting projects in cities are increasingly implemented as a strategy to improve the urban environment. Trees provide multiple benefits in cities, including reduction of urban temperatures, improved air quality, mitigation of storm-water run-off, and provision of wildlife habitat. How urban afforestation affects the properties and functions of urban...

Effects of fire and fuels management on water quality in eastern North America

Treesearch

R. K. Kolka

2012-01-01

Fuels management, especially prescribed fire, can have direct impacts on aquatic resources through deposition of ash to surface waters. On the terrestrial side, fuels management leads to changes in vegetative structure and potentially soil properties that affect ecosystem cycling of water and inorganic and organic constituents. Because surface water systems (streams,...

The combustion of sound and rotten coarse woody debris: a review

Treesearch

Joshua C. Hyde; Alistair M.S. Smith; Roger D. Ottmar; Ernesto C. Alvarado; Penelope Morgan

2011-01-01

Coarse woody debris serves many functions in forest ecosystem processes and has important implications for fire management as it affects air quality, soil heating and carbon budgets when it combusts. There is relatively little research evaluating the physical properties relating to the combustion of this coarse woody debris with even less specifically addressing...

Impacts of all terrain vehicles (ATV) on National Forest lands and grasslands [Abstract

Treesearch

Randy B. Foltz; Kristina A. Yanosek

2005-01-01

The US Forest Service has identified unmanaged all terrain vehicle (ATV) use as a threat to forested lands and grasslands. Some undesirable impacts include severely eroded soils, usercreated unplanned roads, disrupted wetland ecosystems, as well as general habitat destruction and degraded water quality throughout forested lands. More insight on how ATV use affects...

[Accumulation Characteristics and Evaluation of Heavy Metals in Soil-Crop System Affected by Wastewater Irrigation Around a Chemical Factory in Shenmu County].

PubMed

Qi, Yan-bing; Chu, Wan-lin; Pu, Jie; Liu, Meng-yun; Chang, Qing-rui

2015-04-01

Soil heavy metals Cu, Pb, Zn, and Cd, are regarded as "chemical time bombs" because of their propensity for accumulation in the soil and uptake by crops. This ultimately causes human toxicity in both the short and long-term, making farmland ecosystems dangerous to health. In this paper, accumulation and spatial variability of Cu, Zn, Pb and Cd in soil-crop system affected by wastewater irrigation around a chemical factor in northern Shaanxi province were analyzed. Results showed that wastewater irrigation around the chemical factory induced significant accumulation in soils compared with control areas. The average concentrations of available Cu and total Cu were 4.32 mg x kg(-1) and 38.4 mg x kg(-1), which were twice and 1.35 times higher than those of the control area, respectively. Soil Zn and Pb were slightly accumulated. Whereas soil Cd was significantly accumulated and was higher than the critical level of soil environmental quality (II), the available and total Cd concentrations were 0.248 mg x kg(-1) and 1.21 mg x kg(-1), which were 10 and 6.1 times higher than those of the control areas. No significant correlations were found between available and total heavy metals except between available Cd and total Cd. All the heavy metals were mainly accumulated in the top layer (0-10 cm). Spatially, soils and plants high in heavy metal concentration were distributed within the radius of about 100 m from the waste water outlet for Cu, Zn and Cd and about 200 m for Pb, and decreased exponentially with the distance from the factory. Affected by wastewater irrigation, contents of Cu, Pb and Cd in maize were 4.74, 0.129 and 0.036 mg x kg(-1) which were slightly higher than those in the control area. The content of Zn was similar to that in the control area. Affected by the vehicle exhaust, the over standard rate of Pb was 5.7% in maize. All the heavy metals did not show significant correlation between soil and crop, except Cd. The square correlation coefficients were 0.83 and 0.75 between soil available and total Cd with maize. Therefore, the chemical factory contributed to the accumulation of heavy metals in the soil around it, but the contribution to the crop was limited, and thus temporarily caused no threat to human health. The reason for the lower accumulation was the high soil pH and low soil organic matter content. But more attentions should be paid to the higher accumulation of Pb in the maize caused by the vehicle and dust.

Does Aggregation Affect the Redistribution and Quality of Eroded SOC?

NASA Astrophysics Data System (ADS)

Hu, Yaxian; Kuhn, Nikolaus

2015-04-01

A substantial amount of literature has discussed the impacts of soil erosion on global carbon cycling. However, numerous gaps in our knowledge remain unaddressed, for instance, the biogeochemical fate of displaced SOC during transport being one of them. The transport distance and the quality of eroded SOC are the two major factors that determine its fate. Previous laboratory-based research had demonstrated that the effects of aggregation can potentially shorten the transport distance of eroded SOC. The mineralization potential of SOC also differs in sediment fractions of different likely transport distances. It is therefore essential to examine the transport distance and quality of eroded SOC under field conditions with natural rainfall as the agent of erosion. Soil samples from a silty clay soil from Switzerland and a sandy soil from Denmark, were collected in the field this summer after natural rainfall events. The soil from Switzerland was sampled from a field of maize in St. Ursanne (47°20' N 7°09' E) on August 6th, 2014 after a natural rainfall event. A depositional fan consisting of aggregated sediment was formed outside the lower edge of the field. The sandy soil from Denmark was sampled from a farm in Foulum (56°30' N, 9°35' W) on September 4, 2014, after a series of natural rainfall events. Soil samples were collected at different topographic positions along the two slopes. All the soil samples from the two farms were fractionated by a settling tube. Bulk soil from Switzerland and Denmark was also dispersed by ultrasound. The SOC contents of all bulk soils and associated fractions were determined using a carbon analyzer Leco 612 at 1000°C. The quality of SOC in different settling fractions collected from various topographic positions were also determined by stable isotopes of C and N (13C and 15N). Our results show that 1) the aggregate specific SOC distribution evidently differs from the mineral particle specific SOC distribution, indicating that re-distribution of eroded SOC is determined by actual aggregate size distribution rather than mineral particle size distribution. 2) The aggregate specific distributions of SOC content from different positions along hillslopes demonstrate that preferential deposition of SOC-enrich sediment along hillslopes is much more pronounced than the mineral particle specific SOC would suggest. 3) The quality of SOC differs significantly in various settling fractions. The fast settling fractions consist of more of labile SOC, and thus is very likely to be mineralized during transport across landscapes, thereby likely contributing as a source of atmospheric CO2. Overall, effects of aggregation can potentially change the transport distance of eroded SOC and thus skew its redistribution towards the terrestrial deposition.

Black Nitrogen or Plant-Derived Organic Nitrogen - which Form is More Efficiently Sequestered in Soils?

NASA Astrophysics Data System (ADS)

López-Martín, María; Velasco-Molina, Marta; Knicker, Heike

2014-05-01

Input of charcoal after forest fires can lead to considerable changes of the quality and quantity of organic matter in soils (SOM). This affects not only its organic C pool but also shifts its organic N composition from peptideous to N-heterocyclic structures (Knicker et al., 1996). In the present study we sought to understand how this alteration is affecting the N availability in fire affected soils. Therefore, we performed a medium-term pot experiment in which grass material (Lolium perenne) was grown on soil material (Cambisols) of a fire-affected and a fire-unaffected forest. The soils were topped with mixtures of ground fresh grass residues and KNO3 or charred grass material (pyrogenic organic matter; PyOM) with KNO3. Here, either the organic N or the inorganic N was isotopically enriched with 15N. Following the 15N concentration in the soil matrix and the growing plants as a function of incubation time (up to 16 months) by isotopic ratio mass spectrometry allowed us to indentify which N-source is most efficiently stabilized and how PyOM is affecting this process. Preliminary data indicated that only after the germination of the seeds, the concentration of the added inorganic 15N in the soil decreased considerably most likely due to its uptake by the growing plants but also due to N-losses by leaching and volatilization. Additional addition of plant residues or PyOM had no major effect on this behavior. Covering the soil with 15N-grass residues which simulates a litter layer led to a slow increase of the 15N concentration in the mineral soil during the first month. This is best explained by the ongoing incorporation of the litter into the soil matrix. After that a small decrease was observed, showing that the organic N was only slowly mobilized. Addition of 15N-PyOM showed a comparable behavior but with 15N concentration in the soil corresponding to twice of those of the pots amended with 15N-grass residues. After that the 15N concentrations decrease quickly and approached those of the pots with fresh grass litter supporting the mobilization of black nitrogen and its uptake by plants. Our results point to the suggestion that N in PyOM and humified SOM have comparable biochemical stability. In order to test this hypothesis, a further experiment was set up mixtures of soil and humified 15N grass residues or aged 15N grass char to which fresh PyOM or fresh grass residues, respectively, were added. In addition solid-state 15N NMR spectroscopy was applied to disclose the nature of the sequestered N. REFERENCES Knicker, H., Almendros, G., González-Vila, F.J., Martín, F., Lüdemann, H.-D., 1996. 13C- and 15N-NMR spectroscopic examination of the transformation of organic nitrogen in plant biomass during thermal treatment. Soil Biology and Biochemistry, 28, 1053-1060.

Study on nitrification process in two calcareous and non-calcareous contaminated soils

NASA Astrophysics Data System (ADS)

Yazdanpanah, Najme

2010-05-01

Heavy metals are well known to be toxic to most microorganisms when present in high concentration in the soil. They are a serious threat to soil quality due to their persistence after entering the soil. It has been demonstrated repeatedly that heavy metals adversely affect biological functions in soil. While calcareous soils are widespread in Iran, there is lack of information on the behavior of microbial activity in the presence of heavy metals in these soils. Therefore, the aim of this study was to investigate the effect of Cd and Zn as pollutant on nitrification process in two calcareous and non-calcareous soils. After additions of 0, 10 and 100 µg Cd g-1 and 0, 100 and 500 µg Zn g-1 to the soils, nitrification in the presence and absence of ammonium was measured after 45 days incubation. Nitrification results showed that nitrate decreased in both treated soils. Toxic effect of Cd and Zn intensified with increase of metal concentration. The difference of nitrate in samples without ammonium was more pronounced than ammonium treated ones. Nitrification led to decrease in soil pH which was intensified especially in non-calcareous soil. The results of this study indicated that toxic effect of Cd and Zn on measured nitrification was more evident in non- calcareous soil. Keywords: Nitrification, Cadmium, Zinc, Calcareous and non-calcareous soil.

Burning transformations: Fire history effects on organic matter processing from hillslopes to streams

NASA Astrophysics Data System (ADS)

Barnes, R. T.; Gilbertson, A.; Maxwell, K.

2017-12-01

Disturbance strongly regulates material and energy flows, changing ecosystem pattern and process. An increase in the size and severity of fire, particularly in the Intermountain West, over the last several decades is expected to continue due to a warming climate. Predicting how fire will alter the net ecosystem carbon balance requires us to understand how carbon is stored, processed, and transferred. Here we present results from paired watersheds focused on five 2002 severe fires in Colorado to examine how organic matter is processed along the hillslope and within the stream. Comparing soil samples and water extractable organic matter (WEOM) between burned and unburned sites illustrates the impact of fire: burned soils have 50% organic matter (OM) content as unburned soils, regardless of geomorphic position. While a smaller pool, soil OM (SOM) in burned sites is more susceptible to microbial degradation (p<0.001 for 4 of 6 sites), especially in systems with slower vegetative recovery. This is explained, in part, to the water extractable organic matter (WEOM) from unburned soils having a higher C:N than burned sites (p<0.02). This shift in SOM quality is likely due to differing OM inputs (e.g. grasses and forbes vs. trees in burned vs. unburned sites). Comparing results from intact soil column experiments to soil extractions and stream samples, suggests that the majority of this soil derived WEOM does not make it to the stream, potentially getting sorbed deeper in the mineral rich, organic poor, portion of the soil. Interestingly, the systematic shifts in OM amounts and quality (as measured by SUVA, E2:E3, and fluorescence) within the terrestrial system in response to fire, are not seen in stream exports. As such, while there are significant relationships (p<0.05) between stream DOM quality, DOM bioavailability, and stream metabolism, burned watersheds are not exporting DOM that is more bioavailable. In addition, despite different terrestrial OM pools, burned and unburned watersheds export statistically similar amounts of DOM per unit area, suggesting that a larger fraction of OM is transferred from the terrestrial to aquatic ecosystem within fire affected landscapes.

Soil structural quality assessment for soil protection regulation

NASA Astrophysics Data System (ADS)

Johannes, Alice; Boivin, Pascal

2017-04-01

Soil quality assessment is rapidly developing worldwide, though mostly focused on the monitoring of arable land and soil fertility. Soil protection regulations assess soil quality differently, focusing on priority pollutants and threshold values. The soil physical properties are weakly considered, due to lack of consensus and experimental difficulties faced with characterization. Non-disputable, easy to perform and inexpensive methods should be available for environmental regulation to be applied, which is unfortunately not the case. As a consequence, quantitative soil physical protection regulation is not applied, and inexpensive soil physical quality indicators for arable soil management are not available. Overcoming these limitations was the objective of a research project funded by the Swiss federal office for environment (FOEN). The main results and the perspectives of application are given in this presentation. A first step of the research was to characterize soils in a good structural state (reference soils) under different land use. The structural quality was assessed with field expertise and Visual Evaluation of the Soil Structure (VESS), and the physical properties were assessed with Shrinkage analysis. The relationships between the physical properties and the soil constituents were linear and highly determined. They represent the reference properties of the corresponding soils. In a second step, the properties of physically degraded soils were analysed and compared to the reference properties. This allowed defining the most discriminant parameters departing the different structure qualities and their threshold limits. Equivalent properties corresponding to these parameters but inexpensive and easy to determine were defined and tested. More than 90% of the samples were correctly classed with this method, which meets, therefore, the requirements for practical application in regulation. Moreover, result-oriented agri-environmental schemes for soil quality are now proposed to farmers based on these indicators.

Impact of a thermokarst lake on the soil hydrological properties in permafrost regions of the Qinghai-Tibet Plateau, China.

PubMed

Gao, Zeyong; Niu, Fujun; Wang, Yibo; Luo, Jing; Lin, Zhanju

2017-01-01

The formation of thermokarst lakes can degrade alpine meadow ecosystems through changes in soil water and heat properties, which might have an effect on the regional surface water and groundwater processes. In this study, a typical thermokarst lake was selected in the Qinghai-Tibet Plateau (QTP), and the ecological index (S L ) was used to divide the affected areas into extremely affected, severely affected, medium-affected, lightly affected, and non-affected areas, and soil hydrological properties, including saturated hydraulic conductivity and soil water-holding capacity, were investigated. The results showed that the formation of a thermokarst lake can lead to the degradation of alpine meadows, accompanied by a change in the soil physiochemical and hydrological properties. Specifically, the soil structure turned towards loose soil and the soil nutrients decreased from non-affected areas to severely affected areas, but the soil organic matter and available potassium increased slightly in the extremely affected areas. Soil saturated hydraulic conductivity showed a 1.7- to 4.1-fold increase in the lake-surrounding areas, and the highest value (401.9cmd -1 ) was detected in the severely affected area. Soil water-holding capacity decreased gradually during the transition from the non-affected areas to the severely affected areas, but it increased slightly in the extremely affected areas. The principal component analysis showed that the plant biomass was vital to the changes in soil hydrological properties. Thus, the vegetation might serve as a link between the thermokarst lake and soil hydrological properties. In this particular case, it was concluded that the thermokarst lake adversely affected the regional hydrological services in the alpine ecosystem. These results would be useful for describing appropriate hydraulic parameters with the purpose of modeling soil water transportation more accurately in the Qinghai-Tibet Plateau. Copyright © 2016 Elsevier B.V. All rights reserved.

Modeling relationships between catchment attributes and river water quality in southern catchments of the Caspian Sea.

PubMed

Hasani Sangani, Mohammad; Jabbarian Amiri, Bahman; Alizadeh Shabani, Afshin; Sakieh, Yousef; Ashrafi, Sohrab

2015-04-01

Increasing land utilization through diverse forms of human activities, such as agriculture, forestry, urban growth, and industrial development, has led to negative impacts on the water quality of rivers. To find out how catchment attributes, such as land use, hydrologic soil groups, and lithology, can affect water quality variables (Ca(2+), Mg(2+), Na(+), Cl(-), HCO 3 (-) , pH, TDS, EC, SAR), a spatio-statistical approach was applied to 23 catchments in southern basins of the Caspian Sea. All input data layers (digital maps of land use, soil, and lithology) were prepared using geographic information system (GIS) and spatial analysis. Relationships between water quality variables and catchment attributes were then examined by Spearman rank correlation tests and multiple linear regression. Stepwise approach-based multiple linear regressions were developed to examine the relationship between catchment attributes and water quality variables. The areas (%) of marl, tuff, or diorite, as well as those of good-quality rangeland and bare land had negative effects on all water quality variables, while those of basalt, forest land cover were found to contribute to improved river water quality. Moreover, lithological variables showed the greatest most potential for predicting the mean concentration values of water quality variables, and noting that measure of EC and TDS have inversely associated with area (%) of urban land use.

Pasture Management Strategies for Sequestering Soil Carbon - Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Franzluebbers, Alan J.

Pasturelands account for 51 of the 212 Mha of privately held grazing land in the USA. Tall fescue is the most important cool-season perennial forage for many beef cattle producers in the humid region of the USA. A fungal endophyte, Neotyphodium coenophialum, infects the majority of tall fescue stands with a mutualistic association. Ergot alkaloids produced by the endophyte have negative impacts on cattle performance. However, there are indications that endophyte infection of tall fescue is a necessary component of productive and persistent pasture ecology. The objectives of this research were to characterize and quantify changes in soil organic carbonmore » and associated soil properties under tall fescue pastures with and without endophyte infection of grass. Pastures with high endophyte infection had greater concentration of soil organic carbon, but lower concentration of biologically active soil carbon than pastures with low endophyte infection. A controlled experiment suggested that endophyte-infected leaf tissue may directly inhibit the activity of soil microorganisms. Carbon forms of soil organic matter were negatively affected and nitrogen forms were positively affected by endophyte addition to soil. The chemical compounds in endophyte-infected tall fescue (ergot alkaloids) that are responsible for animal health disorders were found in soil, suggesting that these chemicals might be persistent in the environment. Future research is needed to determine whether ergot alkaloids or some other chemicals are responsible for increases in soil organic matter. Scientists will be able to use this information to better understand the ecological impacts of animals grazing tall fescue, and possibly to identify and cultivate other similar associations for improving soil organic matter storage. Another experiment suggested that both dry matter production and soil microbial activity could be affected by the endophyte. Sampling of the cumulative effects of 20 years of tall fescue management indicated that soil organic carbon and nitrogen storage were greater with than without endophyte only under high soil fertility. This extra carbon and nitrogen in soil due to the presence of the endophyte was further found to be located in intermediately sized soil aggregates, which are important for reducing water runoff and improving water quality. These results suggest that well-fertilized tall fescue pastures with a high percentage of plants infected with the endophyte have the potential to help offset the rising carbon dioxide in the atmosphere. This research has also shown positive ecological implications of tall fescue-endophyte association.« less

Improving the mining soil quality for a vegetation cover after addition of sewage sludges: inorganic ions and low-molecular-weight organic acids in the soil solution.

PubMed

Peña, Aránzazu; Mingorance, Mª Dolores; Guzmán-Carrizosa, Ignacio; Fernández-Espinosa, Antonio J

2015-03-01

We assessed the effects of applying stabilized sewage sludge (SSL) and composted sewage sludge (CLV), at 5 and 10% to an acid mining soil. Limed soil (NCL) amended or not with SSL and CLV was incubated for 47 days. We studied the cations and organic and inorganic anions in the soil solution by means of ion chromatography. Liming led to big increases in Ca(2+) and SO4(2-) and to significant decreases in K(+), Mg(2+), NH4(+) and NO3(-). Addition of both organic amendments increased some cations (NH4(+), K(+), Mg(2+), Na(+)) and anions (Cl(-), NO3(-) only with CLV and PO4(3-) only with SSL) and provided a greater amount of low-molecular-weight organic acids (LMWOAs) (SSL more than CLV). Incubation led to decreases in all cations, particularly remarkable for Ca(2+) and Mg(2+) in SSL-10. A decrease in NH4(+) was associated with variations in NO2(-) and NO3(-) resulting from nitrification reactions. During incubation the LMWOAs content tended to decrease similarly to the cations, especially in SSL-10. Chemometric tools revealed a clear discrimination between SSL, CLV and NCL. Furthermore, treatment effects depended upon dose, mainly in SSL. Amendment nature and dose affect the quality of a mining soil and improve conditions for plant establishment. Copyright © 2014 Elsevier Ltd. All rights reserved.

Climate Change, Soils, and Human Health

NASA Astrophysics Data System (ADS)

Brevik, Eric C.

2013-04-01

According to the Intergovernmental Panel on Climate Change, global temperatures are expected to increase 1.1 to 6.4 degrees C during the 21st century and precipitation patterns will be altered by climate change (IPCC, 2007). Soils are intricately linked to the atmospheric/climate system through the carbon, nitrogen, and hydrologic cycles. Altered climate will, therefore, have an effect on soil processes and properties. Studies into the effects of climate change on soil processes and properties are still incomplete, but have revealed that climate change will impact soil organic matter dynamics including soil organisms and the multiple soil properties that are tied to organic matter, soil water, and soil erosion. The exact direction and magnitude of those impacts will be dependent on the amount of change in atmospheric gases, temperature, and precipitation amounts and patterns. Recent studies give reason to believe at least some soils may become net sources of atmospheric carbon as temperatures rise; this is particularly true of high latitude regions with permanently frozen soils. Soil erosion by both wind and water is also likely to increase. These soil changes will lead to both direct and indirect impacts on human health. Possible indirect impacts include temperature extremes, food safety and air quality issues, increased and/or expanded disease incidences, and occupational health issues. Potential direct impacts include decreased food security and increased atmospheric dust levels. However, there are still many things we need to know more about. How climate change will affect the nitrogen cycle and, in turn, how the nitrogen cycle will affect carbon sequestration in soils is a major research need, as is a better understanding of soil water-CO2 level-temperature relationships. Knowledge of the response of plants to elevated atmospheric CO2 given limitations in nutrients like nitrogen and phosphorus and how that affects soil organic matter dynamics is a critical need. There is also a great need for a better understanding of how soil organisms will respond to climate change because those organisms are incredibly important in a number of soil processes, including the carbon and nitrogen cycles. All of these questions are important in trying to understand human health impacts. More information on climate change, soils, and human health issues can be found in Brevik (2012). References Brevik, E.C. 2012. Climate change, soils, and human health. In: E.C. Brevik and L. Burgess (Eds). Soils and human health. CRC Press, Boca Raton, FL. in press. IPCC. 2007. Summary for policymakers. pp. 1-18. In S. Solomon, D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M.Tignor and H.L. Miller (eds). Climate change 2007: the physical science basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, UK.

Effects of golf course management on subsurface soil properties in Iowa

NASA Astrophysics Data System (ADS)

Streeter, Matthew T.; Schilling, Keith E.

2018-05-01

Currently, in the USA and especially in the Midwest region, urban expansion is developing turfgrass landscapes surrounding commercial sites, homes, and recreational areas on soils that have been agriculturally managed for decades. Often, golf courses are at the forefront of conversations concerning anthropogenic environmental impacts as they account for some of the most intensively managed soils in the world. Iowa golf courses provide an ideal location to evaluate whether golf course management is affecting the quality of soils at depth. Our study evaluated how soil properties relating to soil health and resiliency varied with depth at golf courses across Iowa and interpreted relationships of these properties to current golf course management, previous land use, and inherent soil properties. Systematic variation in soil properties including sand content, NO3, and soil organic matter (SOM) were observed with depth at six Iowa golf courses among three landform regions. Variability in sand content was identified between the 20 and 50 cm depth classes at all courses, where sand content decreased by as much as 37 %. Highest concentrations of SOM and NO3 were found in the shallowest soils, whereas total C and P variability was not related to golf course management. Sand content and NO3 were found to be directly related to golf course management, particularly at shallow depths. The effects of golf course management dissipated with depth and deeper soil variations were primarily due to natural geologic conditions. The two abovementioned soil properties were very noticeably altered by golf course management and may directly impact crop productivity, soil health, and water quality, and while NO3 may be altered relatively quickly in soil through natural processes, particle size of the soil may not be altered without extensive mitigation. Iowa golf courses continue to be developed in areas of land use change from historically native prairies and more recently agriculture to urban landscapes. As soils are continually altered by human impacts, it is imperative that we monitor the changes, both physical and chemical, in order to establish management practices that maintain environmental sustainability and productivity.

Indirect Short- and Long-Term Effects of Aboveground Invertebrate and Vertebrate Herbivores on Soil Microarthropod Communities

PubMed Central

Vandegehuchte, Martijn L.; Raschein, Ursina; Schütz, Martin; Gwiazdowicz, Dariusz J.; Risch, Anita C.

2015-01-01

Recognition is growing that besides ungulates, small vertebrate and invertebrate herbivores are important drivers of grassland functioning. Even though soil microarthropods play key roles in several soil processes, effects of herbivores—especially those of smaller body size—on their communities are not well understood. Therefore, we progressively excluded large, medium and small vertebrate and invertebrate herbivores for three growing seasons using size-selective fences in two vegetation types in subalpine grasslands; short-grass and tall-grass vegetation generated by high and low historical levels of ungulate grazing. Herbivore exclusions generally had few effects on microarthropod communities, but exclusion of all herbivore groups resulted in decreased total springtail and Poduromorpha richness compared with exclusion of only ungulates and medium-sized mammals, regardless of vegetation type. The tall-grass vegetation had a higher total springtail richness and mesostigmatid mite abundance than the short-grass vegetation and a different oribatid mite community composition. Although several biotic and abiotic variables differed between the exclusion treatments and vegetation types, effects on soil microarthropods were best explained by differences in nutrient and fibre content of the previous year’s vegetation, a proxy for litter quality, and to a lesser extent soil temperature. After three growing seasons, smaller herbivores had a stronger impact on these functionally important soil microarthropod communities than large herbivores. Over longer time-scales, however, large grazers created two different vegetation types and thereby influenced microarthropod communities bottom-up, e.g. by altering resource quality. Hence, both short- and long-term consequences of herbivory affected the structure of the soil microarthropod community. PMID:25738942

Automated Quality Control of in Situ Soil Moisture from the North American Soil Moisture Database Using NLDAS-2 Products

NASA Astrophysics Data System (ADS)

Ek, M. B.; Xia, Y.; Ford, T.; Wu, Y.; Quiring, S. M.

2015-12-01

The North American Soil Moisture Database (NASMD) was initiated in 2011 to provide support for developing climate forecasting tools, calibrating land surface models and validating satellite-derived soil moisture algorithms. The NASMD has collected data from over 30 soil moisture observation networks providing millions of in situ soil moisture observations in all 50 states as well as Canada and Mexico. It is recognized that the quality of measured soil moisture in NASMD is highly variable due to the diversity of climatological conditions, land cover, soil texture, and topographies of the stations and differences in measurement devices (e.g., sensors) and installation. It is also recognized that error, inaccuracy and imprecision in the data set can have significant impacts on practical operations and scientific studies. Therefore, developing an appropriate quality control procedure is essential to ensure the data is of the best quality. In this study, an automated quality control approach is developed using the North American Land Data Assimilation System phase 2 (NLDAS-2) Noah soil porosity, soil temperature, and fraction of liquid and total soil moisture to flag erroneous and/or spurious measurements. Overall results show that this approach is able to flag unreasonable values when the soil is partially frozen. A validation example using NLDAS-2 multiple model soil moisture products at the 20 cm soil layer showed that the quality control procedure had a significant positive impact in Alabama, North Carolina, and West Texas. It had a greater impact in colder regions, particularly during spring and autumn. Over 433 NASMD stations have been quality controlled using the methodology proposed in this study, and the algorithm will be implemented to control data quality from the other ~1,200 NASMD stations in the near future.

Use of Nitrogen-15 Isotope Method in Soils and Ground Water to Determine Potential Nitrogen Sources Affecting a Municipal Water Supply in Kansas, USA

NASA Astrophysics Data System (ADS)

Townsend, M. A.; Macko, S. A.

2004-12-01

Nitrate-N concentrations have increased to greater than 10 mg/L in a municipal water supply in western Kansas from 1995 to 2002. A study was done by the Kansas Geological Survey using the nitrogen-15 natural abundance isotope method to determine potential sources for the increasing nitrate concentrations. Preliminary results of the isotope analyses on water samples suggest that animal waste and/or denitrification enrichment has affected the water supply. Soil samples from areas near the wells that were not treated with manure show a general increase of nitrogen-15 signature (+9 to +15 \\permil) to a depth of 5 m. Soils are silt loams with measurable carbonate (0.8 to 2 % by weight) in the profile, which may permit volatilization enrichment to occur in the soil profile. Wells in the area range from 11 to 20 m in alluvial deposits with depth to water at approximately 9 m). Nitrate-N values range from 8 to 26 mg/L. Nitrogen-15 values range from (+17 to +28 \\permil) with no obvious source of animal waste near the well sites. There are potential nearby long-term sources of animal waste - an abandoned sewage treatment plant and an agricultural testing farm. One well has a reducing chemistry with a nitrate value of 0.9 mg/L and a nitrogen-15 value of +17 \\permil suggesting that alluvial sediment variation also has an impact on the water quality in the study area. The other wells show values of nitrate and nitrogen-15 that are much greater than the associated soils. The use of nitrogen-15 alone permited limited evaluation of sources of nitrate to ground water particularly in areas with carbonate in the soils. Use of oxygen-18 on nitrate will permit the delineation of the processes affecting the nitrogen in the soil profile and determination of the probable sources and the processes that have affected the nitrogen in the ground water. Final results of the nitrogen-15 and oxygen-18 analyses will be presented.

Phytoremediation of heavy metal polluted soils and water: Progresses and perspectives*

PubMed Central

Lone, Mohammad Iqbal; He, Zhen-li; Stoffella, Peter J.; Yang, Xiao-e

2008-01-01

Environmental pollution affects the quality of pedosphere, hydrosphere, atmosphere, lithosphere and biosphere. Great efforts have been made in the last two decades to reduce pollution sources and remedy the polluted soil and water resources. Phytoremediation, being more cost-effective and fewer side effects than physical and chemical approaches, has gained increasing popularity in both academic and practical circles. More than 400 plant species have been identified to have potential for soil and water remediation. Among them, Thlaspi, Brassica, Sedum alfredii H., and Arabidopsis species have been mostly studied. It is also expected that recent advances in biotechnology will play a promising role in the development of new hyperaccumulators by transferring metal hyperaccumulating genes from low biomass wild species to the higher biomass producing cultivated species in the times to come. This paper attempted to provide a brief review on recent progresses in research and practical applications of phytoremediation for soil and water resources. PMID:18357623

Pollution status of Pakistan: a retrospective review on heavy metal contamination of water, soil, and vegetables.

PubMed

Waseem, Amir; Arshad, Jahanzaib; Iqbal, Farhat; Sajjad, Ashif; Mehmood, Zahid; Murtaza, Ghulam

2014-01-01

Trace heavy metals, such as arsenic, cadmium, lead, chromium, nickel, and mercury, are important environmental pollutants, particularly in areas with high anthropogenic pressure. In addition to these metals, copper, manganese, iron, and zinc are also important trace micronutrients. The presence of trace heavy metals in the atmosphere, soil, and water can cause serious problems to all organisms, and the ubiquitous bioavailability of these heavy metal can result in bioaccumulation in the food chain which especially can be highly dangerous to human health. This study reviews the heavy metal contamination in several areas of Pakistan over the past few years, particularly to assess the heavy metal contamination in water (ground water, surface water, and waste water), soil, sediments, particulate matter, and vegetables. The listed contaminations affect the drinking water quality, ecological environment, and food chain. Moreover, the toxicity induced by contaminated water, soil, and vegetables poses serious threat to human health.

Use of major ion and stable isotope geochemistry to delineate natural and anthropogenic sources of nitrate and sulfate in the Kettle River Basin, British Columbia, Canada

NASA Astrophysics Data System (ADS)

Harker, Leslie; Hutcheon, Ian; Mayer, Bernhard

2015-11-01

The Kettle River Basin in South central British Columbia (Canada) is under increasing anthropogenic pressures affecting both water quantity and quality of surface waters and aquifers. We investigated water quality and sources and processes influencing NO3- and SO42- in the Kettle River Basin using a combination of chemical and isotopic techniques. The dominant water type in the Kettle River Basin is Ca-HCO3 with surface waters having total dissolved solids (TDS) concentrations of < 115 mg/L and groundwaters having TDS values of up to 572 mg/L. Based on δ15NNO3andδ18ONO3 values and concentration data, NO3- in surface waters originates primarily from natural soil nitrification processes, with additional influences from anthropogenic activities, such as waste water effluents at sampling locations downstream from population centres. The source of NO3- in groundwater was predominantly nitrification of soil organic matter, although nitrate in a few groundwater samples originated from anthropogenic sources, including manure or septic systems. The dominant source of SO42- in surface water and groundwater samples was the natural oxidation of sulfide minerals. With increasing distance downstream, surface water δ18OSO4 values increase beyond the range of oxidation of sulfide minerals and into the range of soil and atmospheric-derived SO42- that is in part derived from anthropogenic emissions. Hence, we conclude that recent anthropogenic impacts have affected water quality only marginally at only few sites in the Kettle River Basin. The presented data will serve as an excellent baseline against which future impacts can be assessed.

Land use intensification effects in soil arthropod community of an entisol in Pernambuco State, Brazil.

PubMed

Siqueira, G M; Silva, E F F; Paz-Ferreiro, J

2014-01-01

The interactions between soil invertebrates and land use and management are fundamental for soil quality assessment but remain largely unaddressed. The aim of this study was to evaluate the changes in soil arthropod community of an entisol brought about by different land use systems under semiarid climate in Pernambuco State, Brazil. The soil invertebrate community was sampled using pitfall traps from areas with eight vegetation types by the end of the austral winter. The land uses studied were native thorn forest plus seven agricultural fields planted with elephant grass, apple guava, passion fruit, carrot, maize, tomato, and green pepper. Native vegetation was considered as a reference, whereas the agricultural fields showed a range of soil use intensities. The abundance of organisms, the total and average richness, Shannon's diversity index, and the Pielou uniformity index were determined, and all of these were affected by several crop and soil management practices such as residue cover, weed control, and pesticide application. Our study found differences in community assemblages and composition under different land use systems, but no single taxa could be used as indicator of soil use intensity.

Land Use Intensification Effects in Soil Arthropod Community of an Entisol in Pernambuco State, Brazil

PubMed Central

Siqueira, G. M.; Silva, E. F. F.; Paz-Ferreiro, J.

2014-01-01

The interactions between soil invertebrates and land use and management are fundamental for soil quality assessment but remain largely unaddressed. The aim of this study was to evaluate the changes in soil arthropod community of an entisol brought about by different land use systems under semiarid climate in Pernambuco State, Brazil. The soil invertebrate community was sampled using pitfall traps from areas with eight vegetation types by the end of the austral winter. The land uses studied were native thorn forest plus seven agricultural fields planted with elephant grass, apple guava, passion fruit, carrot, maize, tomato, and green pepper. Native vegetation was considered as a reference, whereas the agricultural fields showed a range of soil use intensities. The abundance of organisms, the total and average richness, Shannon's diversity index, and the Pielou uniformity index were determined, and all of these were affected by several crop and soil management practices such as residue cover, weed control, and pesticide application. Our study found differences in community assemblages and composition under different land use systems, but no single taxa could be used as indicator of soil use intensity. PMID:25431792

[Effect of afforestation modes on soil microbial community and nitrogen functional genes in Hippophae rhamnoides plantation].

PubMed

Yang, Dan; Yu, Xuan; Liu, Xu; Liu, Jin-liana; Zhang, Shun-xiang; Yu, Ze-qun

2015-12-01

The study aimed to assess the effect of different afforestation modes on microbial composition and nitrogen functional genes in soil. Soil samples from a pure Hippophae rhamnoides stand (SS) and three mixed stands, namely, H. rhamnoides and Pinus tabuliformis (SY), H. rhamnoides and Platycladus orientalis (SB), H. rhamnoides and Robinia pseucdoacacia (SC) were selected. The results showed that the total PLFA (TPLFA), bacterial PLFA, gram positive bacterial PLFA (G⁺PLFA) were significantly higher in soil samples from other three stands than those of the pure one. However, no significant difference was found for fungal PLFA among them. The abundance of nifH, amoA, nirK and narG genes were higher in SY and SC than in SS. The TPLFA, G⁺PLFA, gram negative bacterial PLFA (G⁻PLFA), and all of the detected gene abundance were significantly and positively correlated with soil pH, total organic carbon, total nitrogen, ammonium nitrogen and available potassium. Afforestation modes affected indirectly soil microbial composition and functional genes through soil properties. Mixing P. tabuliformis or P. orientalis with H. rhamnoides might be suitable afforestation modes, which might improve soil quality.

A soil-landscape framework for understanding spatial and temporal variability in biogeochemical processes in catchments

NASA Astrophysics Data System (ADS)

McGuire, K. J.; Bailey, S. W.; Ross, D. S.

2017-12-01

Heterogeneity in biophysical properties within catchments challenges how we quantify and characterize biogeochemical processes and interpret catchment outputs. Interactions between the spatiotemporal variability of hydrological states and fluxes and soil development can spatially structure catchments, leading to a framework for understanding patterns in biogeochemical processes. In an upland, glaciated landscape at the Hubbard Brook Experimental Forest (HBEF) in New Hampshire, USA, we are embracing the structure and organization of soils to understand the spatial relations between runoff production zones, distinct soil-biogeochemical environments, and solute retention and release. This presentation will use observations from the HBEF to demonstrate that a soil-landscape framework is essential in understanding the spatial and temporal variability of biogeochemical processes in this catchment. Specific examples will include how laterally developed soils reveal the location of active runoff production zones and lead to gradients in primary mineral dissolution and the distribution of weathering products along hillslopes. Soil development patterns also highlight potential carbon and nitrogen cycling hotspots, differentiate acidic conditions, and affect the regulation of surface water quality. Overall, this work demonstrates the importance of understanding the landscape-level structural organization of soils in characterizing the variation and extent of biogeochemical processes that occur in catchments.

Coal mining activities change plant community structure due to air pollution and soil degradation.

PubMed

Pandey, Bhanu; Agrawal, Madhoolika; Singh, Siddharth

2014-10-01

The aim of this study was to investigate the effects of coal mining activities on the community structures of woody and herbaceous plants. The response of individual plants of community to defilement caused by coal mining was also assessed. Air monitoring, soil physico-chemical and phytosociological analyses were carried around Jharia coalfield (JCF) and Raniganj coalfield. The importance value index of sensitive species minified and those of tolerant species enhanced with increasing pollution load and altered soil quality around coal mining areas. Although the species richness of woody and herbaceous plants decreased with higher pollution load, a large number of species acclimatized to the stress caused by the coal mining activities. Woody plant community at JCF was more affected by coal mining than herbaceous community. Canonical correspondence analysis revealed that structure of herbaceous community was mainly driven by soil total organic carbon, soil nitrogen, whereas woody layer community was influenced by sulphur dioxide in ambient air, soil sulphate and soil phosphorus. The changes in species diversity observed at mining areas indicated an increase in the proportion of resistant herbs and grasses showing a tendency towards a definite selection strategy of ecosystem in response to air pollution and altered soil characteristics.

Viewpoints on impacts of climate change on soil quality

NASA Astrophysics Data System (ADS)

Dilly, Oliver; Pfeiffer, Eva-Maria; Trasar-Cepeda, Carmen; Nannipieri, Paolo

2010-05-01

Climate projections indicate a critical increase in temperature and modification of the precipitation pattern for the next century worldwide (IPCC 2007). Higher temperature increase are expected in polar than in temperate and tropical regions. In addition, studies on the response of microbial metabolism to temperature changes showed lower sensitivity at higher temperature level as analyzed by Q10 values (Kirschbaum 1995). The temperature response as indicated by the Q10 value refers to physiological response including enzyme configuration and substrate availability. For soils from an undisturbed forest site in eastern Amazonia, Knorr et al. (2005) observed even that the apparent pool turnover times are insensitive to temperature and received evidence that non-labile soil organic carbon was more sensitive to temperature than labile soil organic carbon. Linking the climate projections and the findings related to Q10 values suggests that the microbial activity may be stimulated to a higher degree at northern latitudes than at lower latitudes. But few studies address the role of temperature changes on soil organic matter pool and microbial biomass and activities although temperature changes may be important (Dilly et al. 2003). On top, the thawing of permafrost soil (24 % of exposed land in the Northern Hemisphere) represents a further threat since erosion processes will occur and captured gases may evolve to the atmosphere. Finally, dryness and drying-rewetting cycling that are affected by climate change are regulating soil organic carbon turnover (Mamilov and Dilly 2001). The lecture will summarize basic findings and positive feedback on our climate system and also address the concept of ‘soil energ-omics' including the interaction between respiration and microbial colonization and the respective metabolic quotient (Dilly 2006). Key words: Q10, Nitrogen deposition, Permafrost, Carbon turnover, Microbial biomass, adjustment References Dilly, O., 2006. Evaluating soil quality in ecosystems based on modern respiratory approaches. In: Cenci R., Sena F. (eds.) Biodiversity-bioindication to evaluate soil health. European Commission EUR 22245EN, p. 59-64 Dilly O., Blume H.-P., Munch J.C., 2003. Soil microbial activities in Luvisols and Anthrosols during 9 years of region-typical tillage and fertilisation practices in northern Germany. Biogeochemistry 65, 319-339 IPPC 2007. The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (eds Solomon, S. et al.) (Cambridge University Press, 2007). Kirschbaum, M.U.F., 1995. The temperature dependence of soil organic matter decomposition, and the effect of global warming on soil organic C storage. Soil Biology and Biochemistry 27, 753-760 Knorr W., Prentice I.C., House J.I., Holland E.A. 2005. Long-term sensitivity of soil carbon to warming. Nature 433, 298-301 Mamilov, A. Sh., Dilly, O., 2002. Soil microbial eco-physiology as affected by short-term variations in environmental conditions. Soil Biology and Biochemistry 34, 1283-1290

Response of nutrients, minerals, antioxidant leaf pigments, vitamins, polyphenol, flavonoid and antioxidant activity in selected vegetable amaranth under four soil water content.

PubMed

Sarker, Umakanta; Oba, Shinya

2018-06-30

Four selected vegetable amaranths were grown under four soil water content to evaluate their response in nutrients, minerals, antioxidant leaf pigments, vitamins, polyphenol, flavonoid and total antioxidant activity (TAC). Vegetable amaranth was significantly affected by variety, soil water content and variety × soil water content interactions for all the traits studied. Increase in water stress, resulted in significant changes in proximate compositions, minerals (macro and micro), leaf pigments, vitamin, total polyphenol content (TPC), and total flavonoid content (TFC) of vegetable amaranth. Accessions VA14 and VA16 performed better for all the traits studied. Correlation study revealed a strong antioxidant scavenging activity of leaf pigments, ascorbic acid, TPC and TFC. Vegetable amaranth can tolerate soil water stress without compromising the high quality of the final product in terms of nutrients and antioxidant profiles. Therefore, it could be a promising alternative crop in semi-arid and dry areas and also during dry seasons. Copyright © 2018. Published by Elsevier Ltd.

Carbon and geochemical properties of cryosols on the North Slope of Alaska

USGS Publications Warehouse

Mu, Cuicui; Zhang, Tingjun; Schuster, Paul F.; Schaefer, Kevin; Wickland, Kimberly P.; Repert, Deborah A.; Liu, Lin; Schaefer, Tim; Cheng, Guodong

2014-01-01

Cryosols contain roughly 1700 Gt of Soil organic carbon (SOC) roughly double the carbon content of the atmosphere. As global temperature rises and permafrost thaws, this carbon reservoir becomes vulnerable to microbial decomposition, resulting in greenhouse gas emissions that will amplify anthropogenic warming. Improving our understanding of carbon dynamics in thawing permafrost requires more data on carbon and nitrogen content, soil physical and chemical properties and substrate quality in cryosols. We analyzed five permafrost cores obtained from the North Slope of Alaska during the summer of 2009. The relationship between SOC and soil bulk density can be adequately represented by a logarithmic function. Gas fluxes at − 5 °C and 5 °C were measured to calculate the temperature response quotient (Q10). Q10 and the respiration per unit soil C were higher in permafrost-affected soils than that in the active layer, suggesting that decomposition and heterotrophic respiration in cryosols may contribute more to global warming.

Vermicompost Improves Tomato Yield and Quality and the Biochemical Properties of Soils with Different Tomato Planting History in a Greenhouse Study

PubMed Central

Wang, Xin-Xin; Zhao, Fengyan; Zhang, Guoxian; Zhang, Yongyong; Yang, Lijuan

2017-01-01

A greenhouse pot test was conducted to study the impacts of replacing mineral fertilizer with organic fertilizers for one full growing period on soil fertility, tomato yield and quality using soils with different tomato planting history. Four types of fertilization regimes were compared: (1) conventional fertilizer with urea, (2) chicken manure compost, (3) vermicompost, and (4) no fertilizer. The effects on plant growth, yield and fruit quality and soil properties (including microbial biomass carbon and nitrogen, NH4+-N, NO3--N, soil water-soluble organic carbon, soil pH and electrical conductivity) were investigated in samples collected from the experimental soils at different tomato growth stages. The main results showed that: (1) vermicompost and chicken manure compost more effectively promoted plant growth, including stem diameter and plant height compared with other fertilizer treatments, in all three types of soil; (2) vermicompost improved fruit quality in each type of soil, and increased the sugar/acid ratio, and decreased nitrate concentration in fresh fruit compared with the CK treatment; (3) vermicompost led to greater improvements in fruit yield (74%), vitamin C (47%), and soluble sugar (71%) in soils with no tomato planting history compared with those in soils with long tomato planting history; and (4) vermicompost led to greater improvements in soil quality than chicken manure compost, including higher pH (averaged 7.37 vs. averaged 7.23) and lower soil electrical conductivity (averaged 204.1 vs. averaged 234.6 μS/cm) at the end of experiment in each type of soil. We conclude that vermicompost can be recommended as a fertilizer to improve tomato fruit quality and yield and soil quality, particularly for soils with no tomato planting history. PMID:29209343

Vermicompost Improves Tomato Yield and Quality and the Biochemical Properties of Soils with Different Tomato Planting History in a Greenhouse Study.

PubMed

Wang, Xin-Xin; Zhao, Fengyan; Zhang, Guoxian; Zhang, Yongyong; Yang, Lijuan

2017-01-01

A greenhouse pot test was conducted to study the impacts of replacing mineral fertilizer with organic fertilizers for one full growing period on soil fertility, tomato yield and quality using soils with different tomato planting history. Four types of fertilization regimes were compared: (1) conventional fertilizer with urea, (2) chicken manure compost, (3) vermicompost, and (4) no fertilizer. The effects on plant growth, yield and fruit quality and soil properties (including microbial biomass carbon and nitrogen, [Formula: see text]-N, [Formula: see text]-N, soil water-soluble organic carbon, soil pH and electrical conductivity) were investigated in samples collected from the experimental soils at different tomato growth stages. The main results showed that: (1) vermicompost and chicken manure compost more effectively promoted plant growth, including stem diameter and plant height compared with other fertilizer treatments, in all three types of soil; (2) vermicompost improved fruit quality in each type of soil, and increased the sugar/acid ratio, and decreased nitrate concentration in fresh fruit compared with the CK treatment; (3) vermicompost led to greater improvements in fruit yield (74%), vitamin C (47%), and soluble sugar (71%) in soils with no tomato planting history compared with those in soils with long tomato planting history; and (4) vermicompost led to greater improvements in soil quality than chicken manure compost, including higher pH (averaged 7.37 vs. averaged 7.23) and lower soil electrical conductivity (averaged 204.1 vs. averaged 234.6 μS/cm) at the end of experiment in each type of soil. We conclude that vermicompost can be recommended as a fertilizer to improve tomato fruit quality and yield and soil quality, particularly for soils with no tomato planting history.

A simple evaluation of soil quality of waterlogged purple paddy soils with different productivities.

PubMed

Liu, Zhanjun; Zhou, Wei; Lv, Jialong; He, Ping; Liang, Guoqing; Jin, Hui

2015-01-01

Evaluation of soil quality can be crucial for designing efficient farming systems and ensuring sustainable agriculture. The present study aimed at evaluating the quality of waterlogged purple paddy soils with different productivities in Sichuan Basin. The approach involved comprehensive analyses of soil physical and chemical properties, as well as enzyme activities and microbial community structure measured by phospholipid fatty acid analysis (PLFA). A total of 36 soil samples were collected from four typical locations, with 12 samples representing high productivity purple paddy soil (HPPS), medium productivity purple paddy soil (MPPS) and low productivity purple paddy soil (LPPS), respectively. Most measured soil properties showed significant differences (P ≤ 0.05) among HPPS, MPPS and LPPS. Pearson correlation analysis and principal component analysis were used to identify appropriate soil quality indicators. A minimum data set (MDS) including total nitrogen (TN), available phosphorus (AP), acid phosphatase (ACP), total bacteria (TB) and arbuscular mycorrhizal fungi was established and accounted for 82.1% of the quality variation among soils. A soil quality index (SQI) was developed based on the MDS method, whilst HPPS, MPPS and LPPS received mean SQI scores of 0.725, 0.536 and 0.425, respectively, with a ranking of HPPS > MPPS > LPPS. HPPS showed relatively good soil quality characterized by optimal nutrient availability, enzymatic and microbial activities, but the opposite was true of LPPS. Low levels of TN, AP and soil microbial activities were considered to be the major constraints limiting the productivity in LPPS. All soil samples collected were rich in available N, K, Si and Zn, but deficient in available P, which may be the major constraint for the studied regions. Managers in our study area should employ more appropriate management in the LPPS to improve its rice productivity, and particularly to any potential limiting factor.

Sensing technologies to measure metabolic activities in soil and assess its health conditions

NASA Astrophysics Data System (ADS)

De Cesare, Fabrizio; Macagnano, Antonella

2013-04-01

Soil is a complex ecosystem comprised of several and mutually interacting components, both abiotic (organo-mineral associations) and biotic (microbial and pedofaunal populations and plants), where a single parameter depends on other factors and affects the same and other factors, so that a network of influences among organisms coexists with the reciprocal actions between organisms and their environment. Therefore, it is difficult to undoubtedly determine what is the cause and what the effect within relationships between factors and processes. Soil is commonly studied through the evaluation and measurement of single parameters (e.g. the content of soil organic matter (SOM), microbial biomass, enzyme activities, pH, etc.), events (e.g. soil erosion, compaction, etc.) and processes (e.g. soil respiration, carbon fluxes, nitrification/denitrification, etc.), often carried out in laboratory conditions in order to limit the number of factors acting within the ecosystem under study, but missing the information about the global soil environment that way. In the last decade, several scientists have proposed and suggested the need for a holistic approach to soil ecosystems in different contexts. Recently, we have applied a sensing system developed in the last decades and capable of analysing complex mixtures of gases and volatiles (odours or aromas) in atmospheres, namely called electronic nose (EN). Typically, ENs are devices consisting of an array of differentially and partially specific, despite selective, sensors upon diverse coatings of sensitive films, i.e. interacting with single analytes of the same chemical class, despite not highly specific for a single substance, only, but showing also lower extent of cross-selectivity towards compounds of other chemical classes. ENs can be used in the classifications of odours by processing the collected responses of all sensors in the array through pattern recognition analyses, in order to obtain a chemical fingerprint (olfactory fingerprint) typical of the analysed air sample. Due to these features, we decided to apply such a sensing technology to the analyses of soil atmospheres, because several processes in soil, both abiotic and biotic, result in gas and/or volatile production and the dynamics of such releases may also be affected by several additional environmental factors, such as soil moisture, temperature, gas exchange rates with outer atmosphere, adsorption/desorption processes, etc. Then, the analysis of soil atmosphere may provide information about global soil conditions (e.g. soil quality and health), according to a holistic approach, where several factors are contemporarily taken into account. At the same time, the use of such a technology, if adequately trained on purpose, can supply information about a single or a pool of processes sharing similar features, which occur in soil over a certain period of time and mostly affecting soil atmosphere. According to these premises and hypotheses, we demonstrated that EN is an useful technology to measure soil microbial activity, through its correlation to specific metabolic activities occurring in soil (i.e. global and specific respiration and some enzyme activities), but also soil microbial biomass. On the basis of such evidences, we also were able to use this technology to assess the quality and health conditions of soil ecosystems in terms of metabolic indices previously identified, according to some metabolic parameters and biomass quantification of microbial populations. In other studies, we also applied EN technology, despite using a different set of sensors in the array, to analyse the atmosphere of soil ecosystems in order to assess their environmental conditions after contamination with polycyclic aromatic hydrocarbons (PAHs) (i.e. semivolatile - SVOCs - organic pollutants). In this case, EN technology resulted capable of distinguishing between contaminated and uncontaminated soils, according to the differences in a list of substances, occurring in the atmospheres of differently treated soils, which were identified through SPME-GC/MS analyses and then suggested to be responsible for the different classification. Analysing the EN responses, it was also possible to follow the degradation process of pollutants by resident microbial populations over time, on the basis of the contemporary decrease of contaminant and the increased release of CO2. Then, we suggest that EN technology may be usefully employed in the analyses of soil ecosystems in order to both supply information about global soil environment, according to the holistic approach, and about specific processes occurring therein. Furthermore, since EN technology resulted to be effective and successful in detecting processes in soil, in both natural and perturbed conditions, involving microbial populations, which are commonly considered as the most sensitive and responsive to soil environmental modifications, we suggest it might be reasonably employed in analyses concerning the assessment of soil quality and health. Consequently, such a technology may also be used to study several processes involving soil ecosystems, such as soil management practices, soil restoration, soil contamination and remediation, soil fertility, etc.

Response of organic matter quality in permafrost soils to warming

NASA Astrophysics Data System (ADS)

Plaza, C.; Pegoraro, E.; Schuur, E.

2016-12-01

Global warming is predicted to thaw large quantities of the perennially frozen organic matter stored in northern permafrost soils. Upon thaw, this organic matter will be exposed to lateral export to water bodies and to microbial decomposition, which may exacerbate climate change by releasing significant amounts of greenhouse gases. To gain an insight into these processes, we investigated how the quality of permafrost soil organic matter responded to five years of warming. In particular, we sampled control and experimentally warmed soils in 2009 and 2013 from an experiment established in 2008 in a moist acidic tundra ecosystem in Healy, Alaska. We examined surface organic (0 to 15 cm), deep organic (15 to 35 cm), and mineral soil layers (35 to 55 cm) separately by means of stable isotope analysis (δ13C and δ15N) and solid-state 13C nuclear magnetic resonance. Compared to the control, the experimental warming did not affect the isotopic and molecular composition of soil organic matter across the depth profile. However, we did find significant changes with time. In particular, in the surface organic layer, δ13C decreased and alkyl/O-alkyl ratio increased from 2009 to 2013, which indicated variations in soil organic sources (e.g., changes in vegetation) and accelerated decomposition. In the deep organic layer, we found a slight increase in δ15N with time. In the mineral layer, δ13C values decreased slightly, whereas alkyl C/O-alkyl ratio increased, suggesting a preferential loss of relatively more degraded organic matter fractions probably by lateral transport by water flowing through the soil. Acknowledgements: This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 654132. Web site: http://vulcan.comule.com

Soil magnetic susceptibility mapping as a pollution and provenance tool: an example from southern New Zealand

NASA Astrophysics Data System (ADS)

Martin, A. P.; Ohneiser, C.; Turnbull, R. E.; Strong, D. T.; Demler, S.

2018-02-01

The presence or absence, degree and variation of heavy metal contamination in New Zealand soils is a matter of ongoing debate as it affects soil quality, agriculture and human health. In many instances, however, the soil heavy metal concentration data do not exist to answer these questions and the debate is ongoing. To address this, magnetic susceptibility (a common proxy for heavy metal contamination) values were measured in topsoil (0-30 cm) and subsoil (50-70 cm) at grid sites spaced at 8 km intervals across ca. 20 000 km2 of southern New Zealand. Samples were measured for both mass- and volume-specific magnetic susceptibility, with results being strongly, positively correlated. Three different methods of determining anomalies were applied to the data including the topsoil-subsoil difference method, Tukey boxplot method and geoaccumulation index method, with each method filtering out progressively more anomalies. Additional soil magnetic (hysteresis, isothermal remanence and thermomagnetic) measurements were made on a select subset of samples from anomalous sites. Magnetite is the dominant remanence carrying mineral, and magnetic susceptibility is governed by that minerals concentration in soils, rather than mineral type. All except two anomalous sites have a dominant geogenic source (cf. anthropogenic). By proxy, heavy metal contamination in southern New Zealand soils is minimal, making them relatively pristine. The provenance of the magnetic minerals in the anomalous sites can be traced back to likely sources in outcrops of igneous rocks within the same catchment, terrane or rock type: a distance of <100 km but frequently <1 km. Soil provenance is a key step when mapping element or isotopic distribution, vectoring to mineralization or studying soil for agricultural suitability, water quality or environmental regulation. Measuring soil magnetic susceptibility is a useful, quick and inexpensive tool that usefully supplements soil geochemical data.

[Analysis of soil humus and components after 26 years' fertilization by infrared spectroscopy method].

PubMed

Zhang, Yu-Lan; Sun, Cai-Xia; Chen, Zhen-Hua; Li, Dong-Po; Liu, Xing-Bin; Chen, Li-Jun; Wu, Zhi-Jie; Du, Jian-Xiong

2010-05-01

The infrared spectrum was used to discuss structure change of soil humus and components of chemical groups in soil humic acids (HA) and fulvic acids (FA) isolated from soils in different fertilization treatment after 26 year's fertilization. The result indicated that using the infrared spectroscopy method for the determination of humus, humus fractions (HA and FA) and their structure is feasible. Fertilization affected the structure and content of soil humus and aromatization degree. After 26 years' fertilization, the infrared spectrum shapes with different treatments are similar, but the characteristic peak intensity is obviously different, which reflects the effects of different fertilization treatments on the structure and amounts of soil humus or functional groups. Compared with no fertilization, little molecule saccharides decreased and aryl-groups increased under application of inorganic fertilizer or combined application of organic and chemical fertilizer. The effect was greater in Treatment NPK and M+NPK than in Treatment M1 N and M2 N. Organic and NPK fertilizer increased the development of soil and increased soil quality to a certain extent. Results showed that organic fertilization increased aromatization degree of soil humus and humus fractions distinctly. The authors could estimate soil humus evolvement of different fertilization with infrared spectroscopy.

The Multi-Scale Response of Water Quality, Biodiversity and Carbon Sequestration to Coupled Macronutrient Cycling from Source to Sea: TURF2SURF

NASA Astrophysics Data System (ADS)

Cosby, B. J., Jr.; Wade, A. J.; Reinsch, S.; Robins, P. E.; Emmett, B.; Jago, C. F.

2015-12-01

Turf2Surf is a large, multi-disciplinary project that aims to test the hypothesis that the spatial and temporal patterns of water quality, C sequestration and biodiversity are better explained through the large-scale coupling of C, N and P cycles than by single cycle, single system approaches. To achieve this, a catchment-scale study of the River Conwy (349 km2) in Wales is being done with emphasis on determining when, where and how coupled macronutrient (C, N, P) cycling occurs in the biogeochemical hot-spots of the soils, the riparian zone, instream and in the river-estuarine transition zone. A major integrated measurement programme is now largely complete. New data are being analysed to understand which soil properties have greatest influence on above and below-ground productivity including plant traits and how microbial processing is controlled by stoichiometry and nutrient priming. Within the stream network, new understanding is being produced on the in-river algal and whole ecosystem (metabolic) response to CNP additions and the factors affecting the fate and cycling of organic matter. In the estuary, initial results indicate a subsurface jet is causing stratification and a velocity anomaly has been observed. Both are important in terms of suspended matter transport and floc break-up. An integrated model is being built to describe the soil-atmosphere-vegetation processes which is linked, firstly, to flow and water quality models that describe the CNP flux transport and transformations from the headwaters to the estuary and, secondly, to biodiversity models. The purpose of the integrated model is to quantify how coupled CNP cycles may respond to environmental change and thereby affect C sequestration, water quality and biodiversity in the future. The team are now in the major phase of data synthesis and model development and are interested in linking with similar studies involving coupled CNP cycles across the atmospheric-terrestrial-freshwater-coastal continuum.

The Multi-Scale Response of Water Quality, Biodiversity and Carbon Sequestration to Coupled Macronutrient Cycling from Source to Sea: TURF2SURF

NASA Astrophysics Data System (ADS)

Wade, Andrew; Emmett, Bridget; Jago, Colin; Stutter, Marc; Biggs, Jeremy

2016-04-01

Turf2Surf is a large, multi-disciplinary project that aims to test the hypothesis that the spatial and temporal patterns of water quality, C sequestration and biodiversity are better explained through the large-scale coupling of C, N and P cycles than by single cycle, single system approaches. To achieve this, a catchment-scale study of the River Conwy (349 km2) in Wales is being done with emphasis on determining when, where and how coupled macronutrient (C, N, P) cycling occurs in the biogeochemical hot-spots of the soils, the riparian zone, instream and in the river-estuarine transition zone. A major integrated measurement programme is now largely complete. New data are being analysed to understand which soil properties have greatest influence on above and below-ground productivity including plant traits and how microbial processing is controlled by stoichiometry and nutrient priming. Within the stream network, new understanding is being produced on the in-river algal and whole ecosystem (metabolic) response to CNP additions and the factors affecting the fate and cycling of organic matter. In the estuary, initial results indicate a subsurface jet is causing stratification and a velocity anomaly has been observed. Both are important in terms of suspended matter transport and floc break-up. An integrated model is being built to describe the soil-atmosphere-vegetation processes which is linked, firstly, to flow and water quality models that describe the CNP flux transport and transformations from the headwaters to the estuary and, secondly, to biodiversity models. The purpose of the integrated model is to quantify how coupled CNP cycles may respond to environmental change and thereby affect C sequestration, water quality and biodiversity in the future. The team are now in the major phase of data synthesis and model development and are interested in linking with similar studies involving coupled CNP cycles across the atmospheric-terrestrial-freshwater-coastal continuum.

Spatial distributions and seasonal variations of organochlorine pesticides in water and soil samples in Bolu, Turkey.

PubMed

Karadeniz, Hatice; Yenisoy-Karakaş, Serpil

2015-03-01

In this study, a total of 75 water samples (38 groundwater and 37 surface water samples) and 54 surface soil samples were collected from the five districts of Bolu, which is located in the Western Black Sea Region of Turkey in the summer season of 2009. In the autumn season, 17 water samples (surface water and groundwater samples) and 17 soil samples were collected within the city center to observe the seasonal changes of organochlorine pesticides (OCPs). Groundwater and surface water samples were extracted using solid phase extraction. Soil samples were extracted ultrasonically. Sixteen OCP compounds in the standard solution were detected by a gas chromatography-electron capture detector (GC-ECD). Therefore, the method validation was performed for those 16 OCP compounds. However, 13 OCP compounds could be observed in the samples. The concentrations of most OCPs were higher in samples collected in the summer than those in the autumn. The most frequently observed pesticides were endosulfan sulfate and 4,4'-dichlorodiphenyltrichloroethane (DDT) in groundwater samples, α-HCH in surface water samples, and endosulfan sulfate in soil samples. The average concentration of endosulfan sulfate was the highest in water and soil samples. Compared to the literature values, the average concentrations in this study were lower values. Spatial distribution of OCPs was evaluated with the aid of contour maps for the five districts of Bolu. Generally, agricultural processes affected the water and soil quality in the region. However, non-agricultural areas were also affected by pesticides. The concentrations of pesticides were below the legal limits of European directives for each pesticide.

Temporal characterisation of soil-plant natural recovery related to fire severity in burned Pinus halepensis Mill. forests.

PubMed

Moya, D; González-De Vega, S; García-Orenes, F; Morugán-Coronado, A; Arcenegui, V; Mataix-Solera, J; Lucas-Borja, M E; De Las Heras, J

2018-05-28

Despite Mediterranean ecosystems' high resilience to fire, both climate and land use change, and alterations in fire regimes increase their vulnerability to fire by affecting the long-term natural recovery of ecosystem services. The objective of this work is to study the effects of fire severity on biochemical soil indicators, such as chemical composition or enzymatic activity, related to time after fire and natural vegetation recovery (soil-plant interphase). Soil samples from three wildfires occurring 3, 15 and 21 years ago were taken in the south-eastern Iberian Peninsula (semiarid climate). Sampling included three fire severity levels in naturally regenerated (and changing to shrublands) Pinus halepensis Mill. forests. In the short-term post-fire period, phosphorus concentration, electrical conductivity and urease activity were positively linked to fire severity, and also influenced β-glucosidade activity in a negative relationship. During the 15-21-year post-fire period, the effects related to medium-high fire severity were negligible and soil quality indicators were linked to natural regeneration success. The results showed that most soil properties recovered in the long term after fire (21 years). These outcomes will help managers and stakeholders to implement management tools to stabilise soils and to restore burned ecosystems affected by medium-high fire severity. Such knowledge can be considered in adaptive forest management to reduce the negative effects of wildfires and desertification, and to improve the resilience of vulnerable ecosystems in a global change scenario. Copyright © 2018 Elsevier B.V. All rights reserved.

Hell and High Water: Diminished Septic System Performance in Coastal Regions Due to Climate Change

PubMed Central

Cooper, Jennifer A.; Loomis, George W.; Amador, Jose A.

2016-01-01

Climate change may affect the ability of soil-based onsite wastewater treatment systems (OWTS) to treat wastewater in coastal regions of the Northeastern United States. Higher temperatures and water tables can affect treatment by reducing the volume of unsaturated soil and oxygen available for treatment, which may result in greater transport of pathogens, nutrients, and biochemical oxygen demand (BOD5) to groundwater, jeopardizing public and aquatic ecosystem health. The soil treatment area (STA) of an OWTS removes contaminants as wastewater percolates through the soil. Conventional STAs receive wastewater from the septic tank, with infiltration occurring deeper in the soil profile. In contrast, shallow narrow STAs receive pre-treated wastewater that infiltrates higher in the soil profile, which may make them more resilient to climate change. We used intact soil mesocosms to quantify the water quality functions of a conventional and two types of shallow narrow STAs under present climate (PC; 20°C) and climate change (CC; 25°C, 30 cm elevation in water table). Significantly greater removal of BOD5 was observed under CC for all STA types. Phosphorus removal decreased significantly from 75% (PC) to 66% (CC) in the conventional STA, and from 100% to 71–72% in shallow narrow STAs. No fecal coliform bacteria (FCB) were released under PC, whereas up to 17 and 20 CFU 100 mL-1 were released in conventional and shallow narrow STAs, respectively, under CC. Total N removal increased from 14% (PC) to 19% (CC) in the conventional STA, but decreased in shallow narrow STAs, from 6–7% to less than 3.0%. Differences in removal of FCB and total N were not significant. Leaching of N in excess of inputs was also observed in shallow narrow STAs under CC. Our results indicate that climate change can affect contaminant removal from wastewater, with effects dependent on the contaminant and STA type. PMID:27583363

Hell and High Water: Diminished Septic System Performance in Coastal Regions Due to Climate Change.

PubMed

Cooper, Jennifer A; Loomis, George W; Amador, Jose A

2016-01-01

Climate change may affect the ability of soil-based onsite wastewater treatment systems (OWTS) to treat wastewater in coastal regions of the Northeastern United States. Higher temperatures and water tables can affect treatment by reducing the volume of unsaturated soil and oxygen available for treatment, which may result in greater transport of pathogens, nutrients, and biochemical oxygen demand (BOD5) to groundwater, jeopardizing public and aquatic ecosystem health. The soil treatment area (STA) of an OWTS removes contaminants as wastewater percolates through the soil. Conventional STAs receive wastewater from the septic tank, with infiltration occurring deeper in the soil profile. In contrast, shallow narrow STAs receive pre-treated wastewater that infiltrates higher in the soil profile, which may make them more resilient to climate change. We used intact soil mesocosms to quantify the water quality functions of a conventional and two types of shallow narrow STAs under present climate (PC; 20°C) and climate change (CC; 25°C, 30 cm elevation in water table). Significantly greater removal of BOD5 was observed under CC for all STA types. Phosphorus removal decreased significantly from 75% (PC) to 66% (CC) in the conventional STA, and from 100% to 71-72% in shallow narrow STAs. No fecal coliform bacteria (FCB) were released under PC, whereas up to 17 and 20 CFU 100 mL-1 were released in conventional and shallow narrow STAs, respectively, under CC. Total N removal increased from 14% (PC) to 19% (CC) in the conventional STA, but decreased in shallow narrow STAs, from 6-7% to less than 3.0%. Differences in removal of FCB and total N were not significant. Leaching of N in excess of inputs was also observed in shallow narrow STAs under CC. Our results indicate that climate change can affect contaminant removal from wastewater, with effects dependent on the contaminant and STA type.

Identification of the origin of salts in an agricultural area of SE Spain

NASA Astrophysics Data System (ADS)

Acosta, Jose A.; Faz, Angel; Kalbitz, Karsten; Jansen, Boris; Silvia, Martinez-Martinez

2010-05-01

In spite of soil salinity having been widely studied in many part of the world, origin of salinity has not been addresses in detail in some of the most productive agricultural areas of Europe (e.g. southeast of Spain). According to the European Commission, salinization affects about 1 to 3 million ha of the area of the European Union and Candidate Countries. In Europe, most of the salt-affected land surfaces are concentrated in the Mediterranean basin. In Spain, about 3% of the 3.5 million hectares of irrigated land are severely affected by salts and another 15% is at serious risk of imminent salinization. Due to the limited water resources in southeast of Spain, water with marginal quality is used for irrigation. The use of this water has led to degradation, reduction of the land's production capacity and soil salinization. The main aim of the present study was to identify the origin of the salts involved in such salinization, using classical and multivariable statistical techniques. In order to achieve this objective, surface soil samples were collected in January and July 2009 at 48 sites located in a representative lemon production area close to City of Murcia, covering a surface area of 44 km2. Soil pH, electrical conductivity, ionic composition, total organic matter, equivalent calcium carbonate, cation exchange capacity and particle size distribution were determined. The Pearson correlation coefficient, r, was used to measure the relationship between two quantitative variables and principal components analysis was used to study the correlations among anions and cations and their grouping into several factors. Results indicated that the high electrical conductivity found in the study area indeed comes from poor quality irrigation water used for agriculture. Anions and cations responsible of the salinity were chlorides, sulphates, calcium, magnesium and sodium. Mismanagement of water and traditional irrigation system resulted in salt build-up in the soil system. Therefore, there is an urgent need to manage irrigation considering the soil type, climatic factors, and crop requirements. A change to drip irrigation system is desirable in this respect. Phosphate, ammonium, nitrate and potassium found in the soils under study were found to be associated with fertilization. They have been applied to the soil mainly as ammonium nitrate, potassium nitrate, and monoammonium phosphate. The previous indicated that these ions are not involved in secondary salinization of the soils. Finally, SEM-EDX analysis suggested that calcium sulphate found in the agricultural soil of Murcia originated from two sources: i) irrigation water and ii) pedogenic sources. This was confirmed by different crystal morphology and occurrence. In conclusion, multivariable analyses combined with advanced laboratory analysis (e.g. SEM-EDX) are very useful to identify the possible sources of salts. Acknowledgements: to "Fundación Séneca" of "Comunidad Autónoma de Murcia" for its financial support.

Does temperature of charcoal creation affect subsequent mineralization of soil carbon and nitrogen?

NASA Astrophysics Data System (ADS)

Pelletier-Bergeron, S.; Bradley, R.; Munson, A. D.

2012-04-01

Forest fire is the most common form of natural disturbance of boreal forest ecosystems and has primordial influence on successional processes. This may be due in part to the pre-disturbance vegetation development stage and species composition, but these successional pathways could also vary with differences in fire behavior and consequently in fire intensity, defined as the energy released during various phases of a fire. Fire intensity may also affect soil C and N cycling by affecting the quality of the charcoal that is produced. For example, the porosity of coal tends to increase with increasing temperature at which it is produced Higher porosity would logically increase the surface area to which dissolved soil molecules, such as tannins and other phenolics, may be adsorbed. We report on a microcosm study in which mineral and organic soils were jointly incubated for eight weeks with a full factorial array of treatments that included the addition of Kalmia tannins, protein, and wood charcoal produced at five different temperatures. A fourth experimental factor comprised the physical arrangement of the material (stratified vs. mixed), designed to simulate the effect of soil scarification after fire and salvage harvest. We examined the effects of these treatments on soil C and N mineralisation and soil microbial biomass. The furnace temperature at which the charcoal was produced had a significant effect on its physico-chemical properties; increasing furnace temperatures corresponded to a significant increase in % C (P<0.001), and a significant decrease in %O (P<0.001) and %H (P<0.001). Temperature also had significant impacts on microporosity (surface area and volume). Temperature of production had no effect (P=0.1355) on soil microbial biomass. We observed a linear decreasing trend (P<0.001) in qCO2 with increasing temperature of production, which was mainly reflected in a decline in basal respiration. Finally, we found a significant interaction (P=0.010) between temperature of charcoal production x soil mixing in controlling post incubation NH4+ concentrations. We discuss the results in relation to potential implications for changing fire regime and C and N cycles.

The effects of the mineral phase on C stabilization mechanisms and the microbial community along an eroding slope transect

NASA Astrophysics Data System (ADS)

Doetterl, S.; Opfergelt, S.; Cornelis, J.; Boeckx, P. F.; van oost, K.; Six, J.

2013-12-01

An increasing number of studies show the importance of including soil redistribution processes in understanding carbon (C) dynamics in eroding landscapes. The quality and quantity of soil organic carbon in sloping cropland differs with topographic position. These differences are commonly more visible in the subsoil, while the size and composition of topsoil C pools are similar along the hillslope. The type (plant- or microbial-derived) and quality (level of degradation) of C found in a specific soil fraction depends on the interplay between the temporal dynamic of the specific mechanism and it's strength to protect C from decomposition. Here, we present an analysis that aims to clarify the bio/geo-chemical and mineralogical components involved in stabilizing C at various depths and slope positions and how they affect the microbial community and the degradation of C. For this we analyzed soil samples from different soil depths along a slope transect applying (i) a sequential extraction of the reactive soil phase using pyrophosphate, oxalate and dithionite-citrate-bicarbonate, (ii) a semi-quantitative and qualitative analysis of the clay mineralogy, (iii) an analysis of the microbial community using amino sugars and (iv) an analysis of the level of degradation of C in different soil fractions focusing on the soil Lignin signature. The results show that the pattern of minerals and their relative importance in stabilizing C varies greatly along the transect. In the investigated soils, pyrophosphate extractable Manganese, and not Iron or Aluminum as often observed, is strongly correlated to C in the bulk soil and in the non-aggregated silt and clay fractions. This suggests a certain role of Manganese for C stabilization where physical protection is absent. In contrast, pyrophosphate extractable Iron and Aluminum components are largely abundant in water-stable soil aggregates but not correlated to C, suggesting importance of these extracts to stabilize aggregates and, hence, providing physical protection of C. Oxalate extractable amorphous and poorly crystalline minerals are correlated to C, especially for the more recalcitrant C fractions, but only at the depositional site. However, decreasing contents of oxalate extractable elements with depth indicate a temporal limitation of this stabilization mechanism and this is also supported by the results of our lignin extraction. Non-expandable clay minerals experience a relative enrichment at the depositional site while expandable clay minerals experience the same at the eroding site. These changes in clay mineralogy along the slope are partly responsible for the abundance of silt and clay associated C. The changes in soil mineralogy and micro-scale environmental conditions led to an adaptation of the microbial community in comparison to sites not affected by soil redistribution.

Assessing the quality of soil carbon using mid-infrared spectroscopy

EPA Science Inventory

With an increasing focus on carbon sequestration in soils to help offset anthropogenic greenhouse gas emissions, there is a growing need for standardized methods of assessing the quality (i.e., residence time) of soil organic carbon. Information on soil carbon quality is critica...

Nitrate losses, nutrients and heavy metal accumulation from substrates assembled for urban soils reconstruction.

PubMed

Civeira, G; Lavado, R S

2008-09-01

Urban soils may suffer mild to severe degradation as a result of physical and chemical alterations. To reconstruct these soils, a new upper horizon must be created, usually through the application of organic matter, one source of which is biosolids. Different soil mixtures were evaluated with regard to loss of nitrates in percolates and the uptake and incorporation of nutrients and heavy metals into plant tissues. The experiment was conducted in trays; treatments were mixtures of biosolids and a coarse material (e.g., sand or pine wood sawdust), combined in different proportions. Randomized trays were seeded with a mix of tall fescue (Festuca arundinacea L.) and perennial ryegrass (Lolium perenne L.). Plant biomass was quantified. Nitrates in percolates were measured, as were nutrients and heavy metals in mixtures and plant tissues. Plants accumulated substantially more N, and biomass was 40% higher, in the treatments with higher levels of biosolids. The same treatments released more nitrogen and resulted in higher percolate nitrate levels. Plants had normal concentrations of all nutrients, except nitrogen, which was low. Heavy metal concentrations were not significantly different among treatments. Based on the analysis of these data, the proportion of biosolids appears to be the most important factor affecting the quality of reconstructed soil and the rate of improvement. The type of coarse material used did not significantly affect the outcome.

Three Soil Quality Demonstrations for Educating Extension Clientele

ERIC Educational Resources Information Center

Hoorman, James J.

2014-01-01

There is a renewed interest in educating youth, Master Gardeners, and agricultural producers about soil quality. Three soil demonstrations show how soil organic matter increases water holding capacity, improves soil structure, and increases nutrient retention. Exercise one uses clay bricks and sponges to represent mineral soils and soil organic…

40 CFR 264.278 - Unsaturated zone monitoring.

Code of Federal Regulations, 2011 CFR

2011-07-01

... or operator must monitor the soil and soil-pore liquid to determine whether hazardous constituents... unsaturated zone monitoring system that includes soil monitoring using soil cores and soil-pore liquid... the quality of background soil-pore liquid quality and the chemical make-up of soil that has not been...

40 CFR 264.278 - Unsaturated zone monitoring.

Code of Federal Regulations, 2014 CFR

2014-07-01

... or operator must monitor the soil and soil-pore liquid to determine whether hazardous constituents... unsaturated zone monitoring system that includes soil monitoring using soil cores and soil-pore liquid... the quality of background soil-pore liquid quality and the chemical make-up of soil that has not been...

40 CFR 264.278 - Unsaturated zone monitoring.

Code of Federal Regulations, 2012 CFR

2012-07-01

... or operator must monitor the soil and soil-pore liquid to determine whether hazardous constituents... unsaturated zone monitoring system that includes soil monitoring using soil cores and soil-pore liquid... the quality of background soil-pore liquid quality and the chemical make-up of soil that has not been...

40 CFR 264.278 - Unsaturated zone monitoring.

Code of Federal Regulations, 2013 CFR

2013-07-01

... or operator must monitor the soil and soil-pore liquid to determine whether hazardous constituents... unsaturated zone monitoring system that includes soil monitoring using soil cores and soil-pore liquid... the quality of background soil-pore liquid quality and the chemical make-up of soil that has not been...

40 CFR 264.278 - Unsaturated zone monitoring.

Code of Federal Regulations, 2010 CFR

2010-07-01

... or operator must monitor the soil and soil-pore liquid to determine whether hazardous constituents... unsaturated zone monitoring system that includes soil monitoring using soil cores and soil-pore liquid... the quality of background soil-pore liquid quality and the chemical make-up of soil that has not been...

[Assessment of farmland soil quality under different utilization intensity in arid area].

PubMed

Gui, Dong-Wei; Mu, Gui-Jin; Lei, Jia-Qiang; Zeng, Fan-Jiang; Wang, Hui

2009-04-01

Based on the 2005-2007 experimental data in Cele oasis in the southern margin of Tarim Basin of Xinjiang, the soil quality of four typical types of farmland with different utilization intensity, i.e., farmland with high input, farmland with normal input, newly reclaimed farmland, and farmland in oasis' interior, was analyzed and assessed by using sustainable yield index, soil improvement index, and soil quality synthesis index. Among the farmlands, there were significant differences in the contents of soil organic matter, available nitrogen, and available phosphorus. Newly reclaimed farmland had the lowest level of soil quality, while the farmland in oasis' interior had relatively higher soil quality. This study could help the reasonable exploitation and utilization of farmlands in Cele oasis, and the protection of local farmland eco-environment.

Geospatial Modeling of Watershed Quality as an Indicator for Environmental Health

NASA Astrophysics Data System (ADS)

Archer, R.

2016-12-01

The impact of urbanization of rural Tennessee counties on environmental quality and human health and wellbeing has not been well studied, especially in the context of water quality. Between 2015 and 2025, Williamson County, TN is projected to see the strongest rate of population growth in the region, expanding by 33.7 percent. Water quality directly affects the condition of soils, vegetation, and other life forms that depend on water for survival, and therefore is a valid indicator of environmental health. Current reliable data is available on less than half (47%) of waterways in Tennessee. GIS is applied to model the impact of urbanization on rural communities within the Mill Creek watershed in Williamson County, Tennessee. Water quality measurements are integrated with data identifying urbanization and other land development influences assessed over a previous decades in order to identify influences of environmental change impacts on the watershed. The study examines the threat of urbanization to soils, vegetation and other related natural resources as well as the distance of farm areas, pasture grazing, cattle access and manure runoff, construction and landscaping to collection systems leading into the watershed. Combining spatial analysis with water quality interpretation helped to identify and display potential causes and sources of Mill Creek Watershed pollution as well as vulnerable locations susceptible to risk of declining environmental health.

Forest soil carbon oxidation state and oxidative ratio responses to elevated CO 2

DOE PAGES

Hockaday, William C.; Gallagher, Morgan E.; Masiello, Caroline A.; ...

2015-09-21

The oxidative ratio (OR) of the biosphere is the stoichiometric ratio (O 2/CO 2) of gas exchange by photosynthesis and respiration a key parameter in budgeting calculations of the land and ocean carbon sinks. Carbon cycle-climate feedbacks could alter the OR of the biosphere by affecting the quantity and quality of organic matter in plant biomass and soil carbon pools. Here, this study considers the effect of elevated atmospheric carbon dioxide concentrations ([CO 2]) on the OR of a hardwood forest after nine growing seasons of Free-Air CO 2 Enrichment. We measured changes in the carbon oxidation state (C ox)more » of biomass and soil carbon pools as a proxy for the ecosystem OR. The OR of net primary production, 1.039, was not affected by elevated [CO 2]. However, the C ox of the soil carbon pool was 40% higher at elevated [CO 2], and the estimated OR values for soil respiration increased from 1.006 at ambient [CO 2] to 1.054 at elevated [CO 2]. A biochemical inventory of the soil organic matter ascribed the increases in C ox and OR to faster turnover of reduced substrates, lignin and lipids, at elevated [CO 2]. This implicates the heterotrophic soil community response to elevated [CO 2] as a driver of disequilibrium in the ecosystem OR. The oxidation of soil carbon pool constitutes an unexpected terrestrial O 2 sink. Carbon budgets constructed under the assumption of OR equilibrium would equate such a terrestrial O 2 sink to CO 2 uptake by the ocean. We find that the potential for climate-driven disequilibriua in the cycling of O 2 and CO 2 warrants further investigation.« less

Participatory assessment of soil erosion severity and performance of mitigation measured using stakeholders' workshops in Koga catchment, Ethiopia

NASA Astrophysics Data System (ADS)

Lakew, Walle; Baartman, Jantiene; Ritsema, Coen

2016-04-01

There has been little effort to systematically document the experiences and perceptions of farmers on soil erosion and soil and water conservation (SWC) even though a wealth of SWC knowledge and information exists, and there is a great demand to access it. Sustainable Land Management (SLM) has largely evolved through local traditional practices than being adopted on basis of scientific evidence. This research aimed to document the experiences of farmers on soil erosion and conservation, and to increase awareness and participation of the local community in SWC. Participatory stakeholders' workshops were undertaken at local level focused on experiences and perceptions of farmers. The workshops included group discussion and field monitoring of sheet erosion indicators, profiles of rills and gullies and impacts of SWC strategies. Systematic descriptions of the status of soil erosion, soil fertility and yield were used to assess the performances of SWC strategies. Results show that farmers were aware of the harmful effects of ongoing soil erosion and impacts of mitigation strategies on their farms. Sheet erosion was found to be the most damaging form of erosion while rill damage was critical on cereal cultivated farms on steep slopes. Farmers perceived that the desired impacts of SWC practices were attained in general: runoff and soil loss rates decreased, while soil fertility and production increased. The performance of SWC measures were found to be highly affected by the design quality and management strategies on the farm. Comparatively graded stone-faced soil bunds revealed maximum desired impacts and were liked by farmers whereas all level bunds caused water logging and traditional ditches begun incising and affected production of cereals. Bund maintenance practices were low and also distracted the stability of bunds. This calls for further improvement of design of SWC technologies and their maintenance. Further research should integrate the local knowledge for assessment of soil erosion and SWC strategies.

Scale-specific correlations between habitat heterogeneity and soil fauna diversity along a landscape structure gradient.

PubMed

Vanbergen, Adam J; Watt, Allan D; Mitchell, Ruth; Truscott, Anne-Marie; Palmer, Stephen C F; Ivits, Eva; Eggleton, Paul; Jones, T Hefin; Sousa, José Paulo

2007-09-01

Habitat heterogeneity contributes to the maintenance of diversity, but the extent that landscape-scale rather than local-scale heterogeneity influences the diversity of soil invertebrates-species with small range sizes-is less clear. Using a Scottish habitat heterogeneity gradient we correlated Collembola and lumbricid worm species richness and abundance with different elements (forest cover, habitat richness and patchiness) and qualities (plant species richness, soil variables) of habitat heterogeneity, at landscape (1 km(2)) and local (up to 200 m(2)) scales. Soil fauna assemblages showed considerable turnover in species composition along this habitat heterogeneity gradient. Soil fauna species richness and turnover was greatest in landscapes that were a mosaic of habitats. Soil fauna diversity was hump-shaped along a gradient of forest cover, peaking where there was a mixture of forest and open habitats in the landscape. Landscape-scale habitat richness was positively correlated with lumbricid diversity, while Collembola and lumbricid abundances were negatively and positively related to landscape spatial patchiness. Furthermore, soil fauna diversity was positively correlated with plant diversity, which in turn peaked in the sites that were a mosaic of forest and open habitat patches. There was less evidence that local-scale habitat variables (habitat richness, tree cover, plant species richness, litter cover, soil pH, depth of organic horizon) affected soil fauna diversity: Collembola diversity was independent of all these measures, while lumbricid diversity positively and negatively correlated with vascular plant species richness and tree canopy density. Landscape-scale habitat heterogeneity affects soil diversity regardless of taxon, while the influence of habitat heterogeneity at local scales is dependent on taxon identity, and hence ecological traits, e.g. body size. Landscape-scale habitat heterogeneity by providing different niches and refuges, together with passive dispersal and population patch dynamics, positively contributes to soil faunal diversity.

Physical soil quality indicators for monitoring British soils

NASA Astrophysics Data System (ADS)

Corstanje, Ron; Mercer, Theresa G.; Rickson, Jane R.; Deeks, Lynda K.; Newell-Price, Paul; Holman, Ian; Kechavarsi, Cedric; Waine, Toby W.

2017-09-01

Soil condition or quality determines its ability to deliver a range of functions that support ecosystem services, human health and wellbeing. The increasing policy imperative to implement successful soil monitoring programmes has resulted in the demand for reliable soil quality indicators (SQIs) for physical, biological and chemical soil properties. The selection of these indicators needs to ensure that they are sensitive and responsive to pressure and change, e.g. they change across space and time in relation to natural perturbations and land management practices. Using a logical sieve approach based on key policy-related soil functions, this research assessed whether physical soil properties can be used to indicate the quality of British soils in terms of their capacity to deliver ecosystem goods and services. The resultant prioritised list of physical SQIs was tested for robustness, spatial and temporal variability, and expected rate of change using statistical analysis and modelling. Seven SQIs were prioritised: soil packing density, soil water retention characteristics, aggregate stability, rate of soil erosion, depth of soil, soil structure (assessed by visual soil evaluation) and soil sealing. These all have direct relevance to current and likely future soil and environmental policy and are appropriate for implementation in soil monitoring programmes.

Effects of temperature-dependent NOx emissions on continental ozone production

NASA Astrophysics Data System (ADS)

Romer, Paul S.; Duffey, Kaitlin C.; Wooldridge, Paul J.; Edgerton, Eric; Baumann, Karsten; Feiner, Philip A.; Miller, David O.; Brune, William H.; Koss, Abigail R.; de Gouw, Joost A.; Misztal, Pawel K.; Goldstein, Allen H.; Cohen, Ronald C.

2018-02-01

Surface ozone concentrations are observed to increase with rising temperatures, but the mechanisms responsible for this effect in rural and remote continental regions remain uncertain. Better understanding of the effects of temperature on ozone is crucial to understanding global air quality and how it may be affected by climate change. We combine measurements from a focused ground campaign in summer 2013 with a long-term record from a forested site in the rural southeastern United States, to examine how daily average temperature affects ozone production. We find that changes to local chemistry are key drivers of increased ozone concentrations on hotter days, with integrated daily ozone production increasing by 2.3 ppb °C-1. Nearly half of this increase is attributable to temperature-driven increases in emissions of nitrogen oxides (NOx), most likely by soil microbes. The increase of soil NOx emissions with temperature suggests that ozone will continue to increase with temperature in the future, even as direct anthropogenic NOx emissions decrease dramatically. The links between temperature, soil NOx, and ozone form a positive climate feedback.

Conservation tillage versus conventional tillage on carbon stock in a Mediterranean dehesa (southern Spain)

NASA Astrophysics Data System (ADS)

Parras-Alcántara, Luis; Lozano-García, Beatriz

2014-05-01

Understanding soil dynamics is essential for making appropriate land management decisions, as soils can affect the carbon content from the atmosphere, emitting large quantities of CO2 or storing carbon. This property is essential for climate change mitigation strategies as agriculture and forestry soil management can affect the carbon cycle. The dehesa is a Mediterranean silvopastoral system formed by grasslands with scattered oaks (Quercus ilex or Q. suber). The dehesa is a pasture where the herbaceous layer is comprised of either cultivated cereals such as oat, barley and wheat or native vegetation dominated by annual species, which are used as grazing resources. In addition, the dehesa is a practice dedicated to the combined production of Iberian swine, sheep, fuel wood, coal and cork, as well as hunting. The dehesa is characterized by the preservation of forest oaks. In this work, we compared two management practices such as organic farming (OF) and conventional tillage (CT) on soil organic carbon stocks (SOC-S) in Cambisols (CM) and Leptosols (LP), and we analyzed the quality of these soils based on stratification ratio (SR) in a Mediterranean dehesa. MATERIAL AND METHODS An analysis of 85 soil profiles was performed in 2009 in Los Pedroches Valley (Cordoba, southern Spain). Two soil management practices were selected: OF (isolated trees of variable densities —15-25— trees ha-1, mostly holm and cork oaks, and patches of shrubs — cistaceae, fabaceae and lamiaceae— with a herbaceous pasture layer mostly composed of therophytic species and livestock are introduced to provide organic fertilizer to the soil, without ploughing and animal manure from the farms may be incorporated) for 20 years and CT (similar to OF, with ploughing —annual passes with a disc harrow and/or cultivator— is aimed at growing grain for livestock or at clearing the encroaching shrubs) in CM and LP. The dehesas studied were silvopastoral systems without cropping. Soil properties determined were: soil particle size, bulk density, SOC, TN, C:N ratio, stocks and SR. The statistical significance of the differences in the variables between management practices was tested using the Anderson-Darling test at each horizon or a combination of horizons for each soil type. RESULTS The SOC-S was greater in CM (75.64 Mg ha-1) than in LP (44.01 Mg ha-1). SOC-S was very similar in OF and CT (CM [74.90 Mg ha-1-CT; 76.39 Mg ha-1-OF] and LP [44.77 Mg ha-1-CT; 43.25 Mg ha-1-OF]). Data analysis showed that management practices had little effect on SOC storage. Significant differences between soil types and management practices were found in SOC content for different horizons. The SR index was >2 in both soils types (CM and LP) and management systems (OF and CT). These results indicate that the soil is of high quality and that management practices have little influence on SOC-S (Parras-Alcántara et al., 2014) and do not affect SOC storage. REFERENCES Parras-Alcántara, L., Díaz-Jaimes, L., Lozano-García, B., Fernández Rebollo, P., Moreno Elcure, F., Carbonero Muñoz, M.D. 2014. Organic farming has little effect on carbon stock in a Mediterranean dehesa (southern Spain). Catena, 113: 9-17.

Acid sulfate soils are an environmental hazard in Finland

NASA Astrophysics Data System (ADS)

Pihlaja, Jouni

2016-04-01

Acid sulfate soils (ASS) create significant threats to the environment on coastal regions of the Baltic Sea in Finland. The sediments were deposited during the ancient Litorina Sea phase of the Baltic Sea about 7500-4500 years ago. Finland has larger spatial extent of the ASS than any other European country. Mostly based on anthropogenic reasons (cultivation, trenching etc.) ASS deposits are currently being exposed to oxygen which leads to chemical reaction creating sulfuric acid. The acidic waters then dissolve metals form the soil. Acidic surface run off including the metals are then leached into the water bodies weakening the water quality and killing fish or vegetation. In constructed areas acidic waters may corrode building materials. Geological Survey of Finland (GTK) is mapping ASS deposits in Finland. The goal is to map a total of 5 million hectares of the potentially ASS affected region. It has been estimated that the problematic Litorina Sea deposits, which are situated 0-100 m above the recent Baltic Sea shoreline, cover 500 000 hectares area. There are several phases in mapping. The work begins at the office with gathering the existing data, interpreting airborne geophysical data and compiling a field working plan. In the field, quality of the soil is studied and in uncertain cases samples are taken to laboratory analyses. Also electrical conductivity and pH of soil and water are measured in the field. Laboratory methods include multielemental determinations with ICP-OES, analyses of grain size and humus content (LOI), and incubation. So far, approximately 60 % of the potential ASS affected regions in Finland are mapped. Over 15 000 sites have been studied in the field and 4000 laboratory analyses are done. The spatial database presented in the scale of 1: 250 000 can be viewed at the GTK's web pages (http://gtkdata.gtk.fi/hasu/index.html).

Spatial and Temporal Variation of Water Quality in the Bertam Catchment, Cameron Highlands, Malaysia.

PubMed

Rasul, M G; Islam, Mir Sujaul; Yunus, Rosli Bin Mohd; Mokhtar, Mazlin Bin; Alam, Lubna; Yahaya, F M

2017-12-01

  The spatio-temporal variability of water quality associated with anthropogenic activities was studied for the Bertam River and its main tributaries within the Bertam Catchment, Cameron Highlands, Malaysia. A number of physico-chemical parameters of collected samples were analyzed to evaluate their spatio-temporal variability. Nonparametric statistical analysis showed significant temporal and spatial differences (p < 0.05) in most of the parameters across the catchment. Parameters except dissolved oxygen and chemical oxygen demand displayed higher values in rainy season. The higher concentration of total suspended solids was caused by massive soil erosion and sedimentation. Seasonal variations in contaminant concentrations are largely affected by precipitation and anthropogenic influences. Untreated domestic wastewater discharge as well as agricultural runoff significantly influenced the water quality. Poor agricultural practices and development activities at slope areas also affected the water quality within the catchment. The analytical results provided a basis for protection of river environments and ecological restoration in mountainous Bertam Catchment.

Influence of forest and rangeland management on anadromous fish habitat in Western North America: impacts of natural events.

Treesearch

Douglas N. Swanston

1980-01-01

Natural events affecting vegetative cover and the hydrology and stability of a stream and its parent watershed are key factors influencing the quality of anadromous fish habitat. High intensity storms, drought, soil mass movement, and fire have the greatest impacts. Wind, stream icing, and the influence of insects and disease are important locally...

Oak Forest Composition, Site Quality, and Dynamics in Relation to Site Factors in the Southeastern Missouri Ozarks

Treesearch

John M. Kabrick; Stephen R. Shifley; Randy G. Jensen; David R. Larsen; Jennifer K. Grabner

2004-01-01

Physical site factors are known to affect forest species composition but the pattern and variation across forest landscapes has not been well quantified. We discuss relationships between site factors including soil parent materials, depth to dolomite bedrock, aspect, and landform position and the distribution of vegetation, site index, and short-term succession in oak...

Slow-cycle effects of foliar herbivory alter the nitrogen acquisition and population size of Collembola

Treesearch

Mark A. Bradford; Tara Gancos; Christopher J. Frost

2008-01-01

In terrestrial systems there is a close relationship between litter quality and the activity and abundance of decomposers. Therefore, the potential exists for aboveground, herbivore-induced changes in foliar chemistry to affect soil decomposer fauna. These herbivore-induced changes in chemistry may persist across growing seasons. While the impacts of such slow-cycle...

Almond tree and organic fertilization for soil quality improvement in southern Italy.

PubMed

Macci, Cristina; Doni, Serena; Peruzzi, Eleonora; Masciandaro, Grazia; Mennone, Carmelo; Ceccanti, Brunello

2012-03-01

The semi-arid Mediterranean region, characterized by long dry periods followed by heavy bursts of rainfall, is particularly prone to soil erosion. The main goal of this study is to evaluate the soil quality under different practices of bio-physical amelioration which involve the soil-plant system (almond trees) and microorganism-manure. This study, carried out in the South of Italy (Basilicata Region- Pantanello farm), considered two types of fertilization (mineral and organic) and three slope gradients (0, 2 and 6%), in order to evaluate the effects of management practices in resisting soil erosion. Chemical (organic carbon and nitrogen), physical (soil shrinkage and bulk density) and biochemical (dehydrogenase activity and hydrolytic enzyme activities) parameters were selected as markers to follow agro-ecological changes with time. The organic treatment affected soil microbiological and physico-chemical properties by increasing soil nutrient availability, microbial activity, and improving soil structure. The consistently higher values of the hydrolytic enzyme activities (β-glucosidase, phosphatase, urease and protease) often observed in the presence of plants and on the 0 and 2% slopes, suggested the stimulation of nutrient cycles by tree roots, which improve the conditions for soil microorganisms in carrying out their metabolic activity. In the 6% slope and, in particular, in the mineral fertilizer treatment, soil metabolism was lower as suggested by the dehydrogenase activity which was 50% lower than that found in the 0 and 2% slopes, this seemed to be related to a slowdown in the nutrient cycling and organic carbon metabolism. However, on this slope, in both mineral and organic treatments, a significant stimulation of hydrolytic enzyme activities and an improvement of soil structure (reduction of bulk density of about 10% and increase in total shrinkage from 20 to 60%) were observed with plants compared to the control soil. The combination of organic fertilization and almond trees resulted effective, also in the highest slope, in mitigating the degradation processes through the improvement of chemico-nutritional, biochemical and physical soil properties. Copyright © 2010 Elsevier Ltd. All rights reserved.

Soil quality changes after topsoil addition to eroded land

USDA-ARS?s Scientific Manuscript database

Soil-landscape rehabilitation within eroded fields can be accomplished by moving topsoil from depositional to eroded landscape positions. The purpose is to improve soil quality and productivity of the upper root zone in eroded areas of the field. Changes in soil quality may be estimated through chan...

Lignin decomposition and microbial community in paddy soils: effects of alternating redox conditions

NASA Astrophysics Data System (ADS)

Cerli, Chiara; Liu, Qin; Hanke, Alexander; Kaiser, Klaus; Kalbitz, Karsten

2013-04-01

Paddy soils are characterised by interchanging cycles of anaerobic and aerobic conditions. Such fluctuations cause continuous changes in soil solution chemistry as well as in the composition and physiological responses of the microbial community. Temporary deficiency in oxygen creates conditions favourable to facultative or obligates anaerobic bacteria, while aerobic communities can thrive in the period of water absence. These alterations can strongly affect soil processes, in particular organic matter (OM) accumulation and mineralization. In submerged soils, lignin generally constitutes a major portion of the total OM because of hampered degradation under anoxic conditions. The alternating redox cycles resulting from paddy soil management might promote both degradation and preservation of lignin, affecting the overall composition and reactivity of total and dissolved OM. We sampled soils subjected to cycles of anoxic (rice growing period) and oxic (harvest and growth of other crops) conditions since 700 and 2000 years. We incubated suspended Ap material, sampled from the two paddy plus two corresponding non-paddy control soils under oxic and anoxic condition, for 3 months, interrupted by a short period of three weeks (from day 21 to day 43) with reversed redox conditions. At each sampling time (day 2, 21, 42, 63, 84), we determined lignin-derived phenols (by CuO oxidation) as well as phospholipids fatty acids contents and composition. We aimed to highlight changes in lignin decomposition as related to the potential rapid changes in microbial community composition. Since the studied paddy soils had a long history of wet rice cultivation, the microbial community should be well adapted to interchanging oxic and anoxic cycles, therefore fully expressing its activity at both conditions. In non-paddy soil changes in redox conditions caused modification of quantity and composition of the microbial community. On the contrary, in well-established paddy soils the microbial community appeared to be affected by alternating redox conditions more in quantity that in quality. Bacteria represented the largest portion of the living microorganisms, responding promptly to changes in soil redox status. However we did not detect any sign of lignin biodegradation. Relative short (3 weeks) changes in redox conditions had no effect on lignin decomposition or oxidation state. Also, lignin was not altered during oxic incubation. Since fungi represented only small portion of the microbial biomass in the studied soils, they were obviously not capable to cause much degradation, even under favourable conditions. On the contrary, changes in redox conditions strongly affected lignin extractability, regardless of the initial content and direction of change in both paddy and non-paddy soils. This was likely a result of (partial) dissolution and/or pH-induced changes of the surface properties of Fe and Mn hydrous oxides causing the release of mineral-associated lignin-derived phenols. Thus, we speculate that oxidised lignin fragments produced during the (oxic) dry period do not remain in the soils but percolate with water drainage during the flooding period.

Comparison of Portable and Bench-Top Spectrometers for Mid-Infrared Diffuse Reflectance Measurements of Soils.

PubMed

Hutengs, Christopher; Ludwig, Bernard; Jung, András; Eisele, Andreas; Vohland, Michael

2018-03-27

Mid-infrared (MIR) spectroscopy has received widespread interest as a method to complement traditional soil analysis. Recently available portable MIR spectrometers additionally offer potential for on-site applications, given sufficient spectral data quality. We therefore tested the performance of the Agilent 4300 Handheld FTIR (DRIFT spectra) in comparison to a Bruker Tensor 27 bench-top instrument in terms of (i) spectral quality and measurement noise quantified by wavelet analysis; (ii) accuracy of partial least squares (PLS) calibrations for soil organic carbon (SOC), total nitrogen (N), pH, clay and sand content with a repeated cross-validation analysis; and (iii) key spectral regions for these soil properties identified with a Monte Carlo spectral variable selection approach. Measurements and multivariate calibrations with the handheld device were as good as or slightly better than Bruker equipped with a DRIFT accessory, but not as accurate as with directional hemispherical reflectance (DHR) data collected with an integrating sphere. Variations in noise did not markedly affect the accuracy of multivariate PLS calibrations. Identified key spectral regions for PLS calibrations provided a good match between Agilent and Bruker DHR data, especially for SOC and N. Our findings suggest that portable FTIR instruments are a viable alternative for MIR measurements in the laboratory and offer great potential for on-site applications.

Soil organic carbon quality in forested mineral wetlands at different mean annual temperature.

Treesearch

Cinzia Fissore; Christian P. Giardina; Randall K. Kolka; Carl C. Trettin

2009-01-01

Forested mineral soil wetlands (FMSW) store large stocks of soil organic carbon (SOC), but little is known on: (i) whether the quality of SOC stored in these soils (proportion of active versus more resistant SOC compounds) differs from SOC in upland soils; (ii) how the quality of SOC in FMSW varies with mean annual temperature (MAT); and (iii) whether SOC decomposition...

Is the current increase in fire recurrence causing a shift in the soil fertility of Iberian ecosystems?

NASA Astrophysics Data System (ADS)

Mayor, Ángeles G.; Keizer, Jan Jacob; González-Pelayo, Óscar; Valdecantos, Alejandro; Vallejo, Ramón; de Ruiter, Peter

2015-04-01

Since the mid of the last century fire recurrence has increased in the Iberian peninsula and the overall Mediterranean basin due to changes in land use and climate. The warmer and drier climate projected for this region will further increase the risk of wildfire occurrence and of increasing fire recurrence. Although the impact of wildfires on soil nutrient content in this region has been extensively studied, still few works have assessed this impact on the basis of fire recurrence. This study assesses the changes in soil nutrient status of two Iberian ecosystems, Várzea (N Portugal) and Valencia (E Spain), affected by different levels of fire recurrence and where short inter-fire periods have promoted a transition from pine woodlands to shrublands. Trends towards soil fertility loss with increasing fire recurrence (one, two, three or four fires in 37 years) were observed in the two study sites. The sites differed when soil fertility of areas burned several times were compared with long unburned references. In Valencia, overall soil fertility of the surface mineral soil was lower in areas burned two or three times than in long unburned areas, twenty and eight years after the last fire, respectively. On the contrary, total organic matter in Várzea was higher in burned than in unburned soils one year after the occurrence of one or four fires. However, a negative impact of fire was observed for integrated indicators of soil quality, such as hot-water carbon and potentially mineralizable nitrogen, suggesting that fire also had an adverse effect on substrate quality in Várzea. Our results suggest that the current trend of increasing fire recurrence in Southern Europe may result in losses or alterations of soil organic matter, particularly when fire promotes a transition from pine woodland to shrubland.

The Influence of Ecological and Conventional Plant Production Systems on Soil Microbial Quality under Hops (Humulus lupulus)

PubMed Central

Oszust, Karolina; Frąc, Magdalena; Gryta, Agata; Bilińska, Nina

2014-01-01

The knowledge about microorganisms—activity and diversity under hop production is still limited. We assumed that, different systems of hop production (within the same soil and climatic conditions) significantly influence on the composition of soil microbial populations and its functional activity (metabolic potential). Therefore, we compared a set of soil microbial properties in the field experiment of two hop production systems (a) ecological based on the use of probiotic preparations and organic fertilization (b) conventional—with the use of chemical pesticides and mineral fertilizers. Soil analyses included following microbial properties: The total number microorganisms, a bunch of soil enzyme activities, the catabolic potential was also assessed following Biolog EcoPlates®. Moreover, the abundance of ammonia-oxidizing archaea (AOA) was characterized by terminal restriction fragment length polymorphism analysis (T-RFLP) of PCR ammonia monooxygenase α-subunit (amoA) gene products. Conventional and ecological systems of hop production were able to affect soil microbial state in different seasonal manner. Favorable effect on soil microbial activity met under ecological, was more probably due to livestock-based manure and fermented plant extracts application. No negative influence on conventional hopyard soil was revealed. Both type of production fulfilled fertilizing demands. Under ecological production it was due to livestock-based manure fertilizers and fermented plant extracts application. PMID:24897025

Organic matter dynamics along a salinity gradient in Siberian steppe soils

NASA Astrophysics Data System (ADS)

Bischoff, Norbert; Mikutta, Robert; Shibistova, Olga; Dohrmann, Reiner; Herdtle, Daniel; Gerhard, Lukas; Fritzsche, Franziska; Puzanov, Alexander; Silanteva, Marina; Grebennikova, Anna; Guggenberger, Georg

2018-01-01

Salt-affected soils will become more frequent in the next decades as arid and semiarid ecosystems are predicted to expand as a result of climate change. Nevertheless, little is known about organic matter (OM) dynamics in these soils, though OM is crucial for soil fertility and represents an important carbon sink. We aimed at investigating OM dynamics along a salinity and sodicity gradient in the soils of the southwestern Siberian Kulunda steppe (Kastanozem, non-sodic Solonchak, Sodic Solonchak) by assessing the organic carbon (OC) stocks, the quantity and quality of particulate and mineral-associated OM in terms of non-cellulosic neutral sugar contents and carbon isotopes (δ13C, 14C activity), and the microbial community composition based on phospholipid fatty acid (PLFA) patterns. Aboveground biomass was measured as a proxy for plant growth and soil OC inputs. Our hypotheses were that (i) soil OC stocks decrease along the salinity gradient, (ii) the proportion and stability of particulate OM is larger in salt-affected Solonchaks compared to non-salt-affected Kastanozems, (iii) sodicity reduces the proportion and stability of mineral-associated OM, and (iv) the fungi : bacteria ratio is negatively correlated with salinity. Against our first hypothesis, OC stocks increased along the salinity gradient with the most pronounced differences between topsoils. In contrast to our second hypothesis, the proportion of particulate OM was unaffected by salinity, thereby accounting for only < 10 % in all three soil types, while mineral-associated OM contributed > 90 %. Isotopic data (δ13C, 14C activity) and neutral sugars in the OM fractions indicated a comparable degree of OM transformation along the salinity gradient and that particulate OM was not more persistent under saline conditions. Our third hypothesis was also rejected, as Sodic Solonchaks contained more than twice as much mineral-bound OC than the Kastanozems, which we ascribe to the flocculation of OM and mineral components under higher ionic strength conditions. Contrary to the fourth hypothesis, the fungi : bacteria ratio in the topsoils remained fairly constant along the salinity gradient. A possible explanation for why our hypotheses were not affirmed is that soil moisture covaried with salinity along the transect, i.e., the Solonchaks were generally wetter than the Kastanozems. This might cause comparable water stress conditions for plants and microorganisms, either due to a low osmotic or a low matric potential and resulting in (i) similar plant growth and hence soil OC inputs along the transect, (ii) a comparable persistence of particulate OM, and (iii) unaffected fungi : bacteria ratios. We conclude that salt-affected soils contribute significantly to the OC storage in the semiarid soils of the Kulunda steppe, while most of the OC is associated with minerals and is therefore effectively sequestered in the long term.

Land quality evaluation based on sustainable development for gully erosion control and land consolidation project of Yan’ an, China

NASA Astrophysics Data System (ADS)

Wang, Jing; Han, Jichang; Zhang, Yang; Du, Yichun; Bai, Qingjun

2018-01-01

Based on the three land consolidation projects in Yan’an region, the differentiation of the soil capacity, texture, available nutrients, pH etc before and after land consolidation were analyzed, and a comprehensive evaluation of soil quality before and after consolidation was done in this study. The results show that: (1) After the gully-land consolidation, the soil capacity, nitrogen, available P, available K and conductivity are increased, while the organic matter and pH are decreased. With one-year’s cultivation, the soil capacity decreased and the organic matter increased. After the slope-land consolidation, the soil physical and chemical properties have similar trends with the gullies, but the change is more significant. (2)No matter for gully or slope, the soil quality declines where the land just get consolidated, and the slope has more significant declining. With one-year’s cultivation, the soil quality of the gully has more rapid recovery with one grade uplift. (3) The correlation coefficient method was used to give a comprehensive evaluation of the soil quality, to considerate of the changes of the coefficients of the factors and the evaluation object. The evaluation can well reflect the actual situation of the soil quality, give reference to the soil quality evaluation for consolidated land, and the results may provide basis for the performance evaluation of the Yan’an land consolidation projects.

The Rhizosphere Bacterial Microbiota of Vitis vinifera cv. Pinot Noir in an Integrated Pest Management Vineyard.

PubMed

Novello, Giorgia; Gamalero, Elisa; Bona, Elisa; Boatti, Lara; Mignone, Flavio; Massa, Nadia; Cesaro, Patrizia; Lingua, Guido; Berta, Graziella

2017-01-01

Microorganisms associated with Vitis vinifera (grapevine) can affect its growth, health and grape quality. The aim of this study was to unravel the biodiversity of the bacterial rhizosphere microbiota of grapevine in an integrated pest management vineyard located in Piedmont, Italy. Comparison between the microbial community structure in the bulk and rhizosphere soil (variable: space) were performed. Moreover, the possible shifts of the bulk and rhizosphere soil microbiota according to two phenological stages such as flowering and early fruit development (variable: time) were characterized. The grapevine microbiota was identified using metagenomics and next-generation sequencing. Biodiversity was higher in the rhizosphere than in the bulk soil, independent of the phenological stage. Actinobacteria were the dominant class with frequencies ≥ 50% in all the soil samples, followed by Proteobacteria, Gemmatimonadetes, and Bacteroidetes. While Actinobacteria and Proteobacteria are well-known as being dominant in soil, this is the first time the presence of Gemmatimonadetes has been observed in vineyard soils. Gaiella was the dominant genus of Actinobacteria in all the samples. Finally, the microbiota associated with grapevine differed from the bulk soil microbiota and these variations were independent of the phenological stage of the plant.

Soil properties and enzyme activities as affected by biogas slurry irrigation in the Three Gorges Reservoir areas of China.

PubMed

Chen, Shiling; Yu, Weiwei; Zhang, Zhi; Luo, Surong

2015-03-01

Biogas slurry, as a quality organic fertilizer, is widely used on large scale livestock farmland in Southwest China. In the present study, slurry collected from anaerobic tank of dairy farm was used to irrigate farmland having typical purple soil in Chongquing, China. The study revealed that irrigation with biogasslurry increased soil ammonium nitrogen and soil nitrate by 47.8 and 19% respectively as compared to control check. The average soil available phosphorus and soil phosphorus absorption co-efficient changed slightly. Relative enzyme activities of N and P transformation were indicated by catalase, urease, invertase and phosphatase activity. Irrigation period and irrigation quantity were selected as variable factor Catalase, invertase and urease activity was highest when irrigation period and irrigation quantitiy was 4 days and 500 ml; whereas highest phosphatase activity increased significantly in purple irrigated by biogas slurry. The result of the present study is helpful in finding optimum irrigation conditions required for enzyme activity within defined range. It further reveals that biogas slurry enriches soil with various nutrients by enhancing N, P content and enzyme activities as well as it also deals with large number of biogas slurry for protecting the environment.

Soil quality assessment using weighted fuzzy association rules

USGS Publications Warehouse

Xue, Yue-Ju; Liu, Shu-Guang; Hu, Yue-Ming; Yang, Jing-Feng

2010-01-01

Fuzzy association rules (FARs) can be powerful in assessing regional soil quality, a critical step prior to land planning and utilization; however, traditional FARs mined from soil quality database, ignoring the importance variability of the rules, can be redundant and far from optimal. In this study, we developed a method applying different weights to traditional FARs to improve accuracy of soil quality assessment. After the FARs for soil quality assessment were mined, redundant rules were eliminated according to whether the rules were significant or not in reducing the complexity of the soil quality assessment models and in improving the comprehensibility of FARs. The global weights, each representing the importance of a FAR in soil quality assessment, were then introduced and refined using a gradient descent optimization method. This method was applied to the assessment of soil resources conditions in Guangdong Province, China. The new approach had an accuracy of 87%, when 15 rules were mined, as compared with 76% from the traditional approach. The accuracy increased to 96% when 32 rules were mined, in contrast to 88% from the traditional approach. These results demonstrated an improved comprehensibility of FARs and a high accuracy of the proposed method.

On quantifying active soil carbon using mid-infrared ...

EPA Pesticide Factsheets

Soil organic matter (SOM) is derived from plant or animal residues deposited to soil and is in various stages of decomposition and mineralization. Total SOM is a common measure of soil quality, although due to its heterogeneous composition SOM can vary dramatically in terms of its biochemical properties and residence times, which ultimately affect soil heath and function. One operationally defined SOM fraction is “active soil carbon” (ASC) which is thought to consist of readily oxidizable SOM that is responsive to management practices and may provide one measure of “soil health” closely associated with soil biological activity. ASC can be a useful indicator to assist farmers and land managers in their selection of soil management practices to maintain ASC or to build total SOM. ASC has generally been measured using permanganate oxidation, a costly and time-intensive procedure. Chemometric modeling using mid-infrared spectroscopy (MIR) has been successfully used to estimate a range of soil properties, including total organic carbon (TOC) and particulate organic carbon (POC). Consequently, we hypothesized that we could use MIR to estimate ASC. Here we report on a method that uses MIR and chemometric signal processing to quantify TOC and ASC on a variety of soils collected serially and seasonally from a maximum of 76 locations across the United States. TOC was measured using high temperature oxidation and ASC was measured as permanganate-oxidizabl

Drylands soil bacterial community is affected by land use change and different irrigation practices in the Mezquital Valley, Mexico.

PubMed

Lüneberg, Kathia; Schneider, Dominik; Siebe, Christina; Daniel, Rolf

2018-01-23

Dryland agriculture nourishes one third of global population, although crop irrigation is often mandatory. As freshwater sources are scarce, treated and untreated wastewater is increasingly used for irrigation. Here, we investigated how the transformation of semiarid shrubland into rainfed farming or irrigated agriculture with freshwater, dam-stored or untreated wastewater affects the total (DNA-based) and active (RNA-based) soil bacterial community composition, diversity, and functionality. To do this we collected soil samples during the dry and rainy seasons and isolated DNA and RNA. Soil moisture, sodium content and pH were the strongest drivers of the bacterial community composition. We found lineage-specific adaptations to drought and sodium content in specific land use systems. Predicted functionality profiles revealed gene abundances involved in nitrogen, carbon and phosphorous cycles differed among land use systems and season. Freshwater irrigated bacterial community is taxonomically and functionally susceptible to seasonal environmental changes, while wastewater irrigated ones are taxonomically susceptible but functionally resistant to them. Additionally, we identified potentially harmful human and phytopathogens. The analyses of 16 S rRNA genes, its transcripts and deduced functional profiles provided extensive understanding of the short-term and long-term responses of bacterial communities associated to land use, seasonality, and water quality used for irrigation in drylands.

Biochar affects soil organic matter cycling and microbial functions but does not alter microbial community structure in a paddy soil.

PubMed

Tian, Jing; Wang, Jingyuan; Dippold, Michaela; Gao, Yang; Blagodatskaya, Evgenia; Kuzyakov, Yakov

2016-06-15

The application of biochar (BC) in conjunction with mineral fertilizers is one of the most promising management practices recommended to improve soil quality. However, the interactive mechanisms of BC and mineral fertilizer addition affecting microbial communities and functions associated with soil organic matter (SOM) cycling are poorly understood. We investigated the SOM in physical and chemical fractions, microbial community structure (using phospholipid fatty acid analysis, PLFA) and functions (by analyzing enzymes involved in C and N cycling and Biolog) in a 6-year field experiment with BC and NPK amendment. BC application increased total soil C and particulate organic C for 47.4-50.4% and 63.7-74.6%, respectively. The effects of BC on the microbial community and C-cycling enzymes were dependent on fertilization. Addition of BC alone did not change the microbial community compared with the control, but altered the microbial community structure in conjunction with NPK fertilization. SOM fractions accounted for 55% of the variance in the PLFA-related microbial community structure. The particulate organic N explained the largest variation in the microbial community structure. Microbial metabolic activity strongly increased after BC addition, particularly the utilization of amino acids and amines due to an increase in the activity of proteolytic (l-leucine aminopeptidase) enzymes. These results indicate that microorganisms start to mine N from the SOM to compensate for high C:N ratios after BC application, which consequently accelerate cycling of stable N. Concluding, BC in combination with NPK fertilizer application strongly affected microbial community composition and functions, which consequently influenced SOM cycling. Copyright © 2016 Elsevier B.V. All rights reserved.

Urban and industrial land uses have a higher soil biological quality than expected from physicochemical quality.

PubMed

Joimel, Sophie; Schwartz, Christophe; Hedde, Mickaël; Kiyota, Sayuri; Krogh, Paul Henning; Nahmani, Johanne; Pérès, Guénola; Vergnes, Alan; Cortet, Jérôme

2017-04-15

Despite their importance both in soil functioning and as soil indicators, the response of microarthropods to various land uses is still unclear. The aim of this study is to assess the effect of land use on microarthropod diversity and determine whether a soil's biological quality follows the same physicochemical quality-based gradient from forest, agriculture-grassland, agriculture-arable land, vineyards, urban vegetable gardens to urban, industrial, traffic, mining and military areas. A database compiling the characteristics of 758 communities has been established. We calculated Collembola community indices including: species richness, Pielou's evenness index, collembolan life forms, the abundance of Collembola and of Acari, the Acari/Collembola abundance ratio, and the Collembolan ecomorphological index. Results show that agricultural land use was the most harmful for soil microarthropod biodiversity, whilst urban and industrial land uses give the same level of soil biological quality as forests do. Furthermore, differences between the proportions of Acari and ecomorphological groups were observed between land uses. This study, defining soil microarthropod diversity baselines for current land uses, should therefore help in managing and preserving soil microarthropod biodiversity, especially by supporting the preservation of soil quality. Copyright © 2017 Elsevier B.V. All rights reserved.

Manipulative lowering of the water table during summer does not affect CO2 emissions and uptake in a fen in Germany.

PubMed

Muhr, Jan; Höhle, Juliane; Otieno, Dennis O; Borken, Werner

2011-03-01

We simulated the effect of prolonged dry summer periods by lowering the water table on three manipulation plots (D(1-3)) in a minerotrophic fen in southeastern Germany in three years (2006-2008). The water table at this site was lowered by drainage and by excluding precipitation; three nonmanipulated control plots (C(1-3)) served as a reference. We found no significant differences in soil respiration (R(Soil)), gross primary production (GPP), or aboveground respiration (R(AG)) between the C(1-3) and D(1-3) plots in any of the measurement years. The water table on the control plots was naturally low, with a median water table (2006-2008) of 8 cm below the surface, and even lower during summer when respiratory activity was highest, with median values (C(1-3)) between 11 and 19 cm below the surface. If it is assumed that oxygen availability in the uppermost 10 cm was not limited by the location of the water table, manipulative lowering of the water table most likely increased oxygen availability only in deeper peat layers where we expect R(Soil) to be limited by poor substrate quality rather than anoxia. This could explain the lack of a manipulation effect. In a second approach, we estimated the influence of the water table on R(Soil) irrespective of treatment. The results showed a significant correlation between R(Soil) and water table, but with R(Soil) decreasing at lower water tables rather than increasing. We thus conclude that decomposition in the litter layer is not limited by waterlogging in summer, and deeper peat layers bear no significant decomposition potential due to poor substrate quality. Consequently, we do not expect enhanced C losses from this site due to increasing frequency of dry summers. Assimilation and respiration of aboveground vegetation were not affected by water table fluctuations between 10 and >60 cm depth, indicating the lack of stress resulting from either anoxia (high water table) or drought (low water table).

Understanding soil health by capitalizing on long-term field studies

NASA Astrophysics Data System (ADS)

Tavakkoli, Ehsan; Wang, Zhe; VanZweieten, Lukas; Rose, Michael

2017-04-01

Microbial biodiversity in Australian agricultural soils is of paramount importance as it plays a critical role in regulating soil health, plant productivity, and the cycling of carbon, nitrogen, and other nutrients. Agricultural practices strongly affect soil microbial communities by changing the physical and chemical characteristics of the soil in which microorganisms live, thereby affecting their abundance, diversity, and activity. Despite its importance, the specific responses of various microbial groups to changing environmental conditions (e.g. increased/decreased carbon in response to land management) in agricultural soils are not well understood. This knowledge gap is largely due to previous methodological limitations that, until recently, did not allow microbial diversity and functioning to be meaningfully investigated on large numbers of samples. We sampled soils from a field trial on the effect of strategic tillage in no-till systems to examine the potential impact of tillage and stubble management on soil microbial composition. To determine the relative abundance of bacteria and fungi, we used quantitative PCR (qPCR), and to analyze the composition and diversity of the bacterial and fungal communities, we used bar-coded high-throughput sequencing. Bioinformatics of the sequencing generated data was performed using a previously scripted and tested pipeline, and involved allocation of the relevant sequences to their samples of origin according to the bar-code. In parallel, changes in soil quality and microbial functionality were determined using multi-enzyme activity assay and multiple substrate-induced respiration. The extracellular enzyme activities that were measured include: β-1,4-glucosidase, β-D-cellobiohydrolase, β-Xylosidase, and α-1,4-glucosidase which are all relevant to the C cycle; β-1,4-N-acetylglucosaminidase and L-leucine aminopeptidase which are both relevant to the N cycle associated and associated with protein catabolism. In this presentation, analyses of soil health and functionality in relation to its response to various agronomic practices and implications for C sequestration and nutrient cycling will be discussed.

Global dust cycle

NASA Astrophysics Data System (ADS)

Ridgwell, Andy

Dust, micron to submicron particles and mostly comprising soil mineral fragments, affects a multitude of climatic and biogeochemical processes during its journey from its sources on land to sinks on land and in the ocean. Suspended in the atmosphere, the presence of dust can alter both shortwave and longwave radiation balances, enhance cloud nucleation, and affect photochemical reaction rates. Deposited to the land surface, dust has beneficial impacts on soil quality but detrimental implications for human health. At the interface of surface ocean and lower atmosphere, dust deposited to seawater supplies plankton with the essential micronutrient iron and hence provides an important control on marine ecosystems. This chapter reviews these various roles of dust in the Earth system; summarizes the factors controlling the production, transport, and deposition of dust; and, because the causes and consequences of dust are interlinked via climate and atmospheric CO2, discusses the potential importance of dusty feedback in past and future climate change.

Does wastewater from olive mills induce toxicity and water repellency in soil?

NASA Astrophysics Data System (ADS)

Peikert, B.; Bandow, N.; Schaumann, G. E.

2012-04-01

Olive oil mill wastewater is the effluent generated by the olive oil extraction process. It is the main waste product of this industry mainly being produced in the Mediterranean Basin. Because proper treatment options are rare it is often disposed into the environment, e.g. fields or wadies. Due to its high concentration of fatty acids and phytotoxic phenolic compounds and its high chemical and biological oxygen demand, olive oil mill wastewater becomes a serious environmental problem. In this screening study we investigated long-term effects of olive oil mill wastewater application on soil properties in several locations in the West Bank and Israel. We determined wettability via water drop penetration time and the contact angle as well as general soil properties including pH, EC, carbon content, and we conducted thermogravimetrical analyses in order to characterize the impact of the waste water on the quality of soil organic matter. Our results show that application of olive oil mill wastewater has various effects. We determined contact angles between 110 and 120° and water drop penetration times up to 1367 s indicating significant reduction in wettability. Furthermore, soil carbon and nitrogen content and water extractable organic matter increased as well as electric conductivity, which could be pointed out as a fertilizing effect. In contrast soil pH was significantly reduced. Conducting thermal analyses we observed an increase in the labile and refractory carbon fraction. Probably first one is responsible for induced water repellency. As a consequence the reduced wettability negatively affects soil quality. It would therefore be promising to minimize the hydrophobizing impacts without losing fertilizing effects of the olive oil mill wastewater.

Interactive effects of MnO2, organic matter and pH on abiotic formation of N2O from hydroxylamine in artificial soil mixtures.

PubMed

Liu, Shurong; Berns, Anne E; Vereecken, Harry; Wu, Di; Brüggemann, Nicolas

2017-02-01

Abiotic conversion of the reactive nitrification intermediate hydroxylamine (NH 2 OH) to nitrous oxide (N 2 O) is a possible mechanism of N 2 O formation during nitrification. Previous research has demonstrated that manganese dioxide (MnO 2 ) and organic matter (OM) content of soil as well as soil pH are important control variables of N 2 O formation in the soil. But until now, their combined effect on abiotic N 2 O formation from NH 2 OH has not been quantified. Here, we present results from a full-factorial experiment with artificial soil mixtures at five different levels of pH, MnO 2 and OM, respectively, and quantified the interactive effects of the three variables on the NH 2 OH-to-N 2 O conversion ratio (R NH2OH-to-N2O ). Furthermore, the effect of OM quality on R NH2OH-to-N2O was determined by the addition of four different organic materials with different C/N ratios to the artificial soil mixtures. The experiments revealed a strong interactive effect of soil pH, MnO 2 and OM on R NH2OH-to-N2O . In general, increasing MnO 2 and decreasing pH increased R NH2OH-to-N2O , while increasing OM content was associated with a decrease in R NH2OH-to-N2O . Organic matter quality also affected R NH2OH-to-N2O . However, this effect was not a function of C/N ratio, but was rather related to differences in the dominating functional groups between the different organic materials.

Interactive effects of MnO2, organic matter and pH on abiotic formation of N2O from hydroxylamine in artificial soil mixtures

NASA Astrophysics Data System (ADS)

Liu, Shurong; Berns, Anne E.; Vereecken, Harry; Wu, Di; Brüggemann, Nicolas

2017-02-01

Abiotic conversion of the reactive nitrification intermediate hydroxylamine (NH2OH) to nitrous oxide (N2O) is a possible mechanism of N2O formation during nitrification. Previous research has demonstrated that manganese dioxide (MnO2) and organic matter (OM) content of soil as well as soil pH are important control variables of N2O formation in the soil. But until now, their combined effect on abiotic N2O formation from NH2OH has not been quantified. Here, we present results from a full-factorial experiment with artificial soil mixtures at five different levels of pH, MnO2 and OM, respectively, and quantified the interactive effects of the three variables on the NH2OH-to-N2O conversion ratio (RNH2OH-to-N2O). Furthermore, the effect of OM quality on RNH2OH-to-N2O was determined by the addition of four different organic materials with different C/N ratios to the artificial soil mixtures. The experiments revealed a strong interactive effect of soil pH, MnO2 and OM on RNH2OH-to-N2O. In general, increasing MnO2 and decreasing pH increased RNH2OH-to-N2O, while increasing OM content was associated with a decrease in RNH2OH-to-N2O. Organic matter quality also affected RNH2OH-to-N2O. However, this effect was not a function of C/N ratio, but was rather related to differences in the dominating functional groups between the different organic materials.

Denitrification in Agricultural Soils: Integrated control and Modelling at various scales (DASIM)

NASA Astrophysics Data System (ADS)

Müller, Christoph; Well, Reinhard; Böttcher, Jürgen; Butterbach-Bahl, Klaus; Dannenmann, Michael; Deppe, Marianna; Dittert, Klaus; Dörsch, Peter; Horn, Marcus; Ippisch, Olaf; Mikutta, Robert; Senbayram, Mehmet; Vogel, Hans-Jörg; Wrage-Mönnig, Nicole; Müller, Carsten

2016-04-01

The new research unit DASIM brings together the expertise of 11 working groups to study the process of denitrification at unprecedented spatial and temporal resolution. Based on state-of-the art analytical techniques our aim is to develop improved denitrification models ranging from the microscale to the field/plot scale. Denitrification, the process of nitrate reduction allowing microbes to sustain respiration under anaerobic conditions, is the key process returning reactive nitrogen as N2to the atmosphere. Actively denitrifying communities in soil show distinct regulatory phenotypes (DRP) with characteristic controls on the single reaction steps and end-products. It is unresolved whether DRPs are anchored in the taxonomic composition of denitrifier communities and how environmental conditions shape them. Despite being intensively studied for more than 100 years, denitrification rates and emissions of its gaseous products can still not be satisfactorily predicted. While the impact of single environmental parameters is well understood, the complexity of the process itself with its intricate cellular regulation in response to highly variable factors in the soil matrix prevents robust prediction of gaseous emissions. Key parameters in soil are pO2, organic matter content and quality, pH and the microbial community structure, which in turn are affected by the soil structure, chemistry and soil-plant interactions. In the DASIM research unit, we aim at the quantitative prediction of denitrification rates as a function of microscale soil structure, organic matter quality, DRPs and atmospheric boundary conditions via a combination of state-of-the-art experimental and analytical tools (X-ray μCT, 15N tracing, NanoSIMS, microsensors, advanced flux detection, NMR spectroscopy, and molecular methods including next generation sequencing of functional gene transcripts). We actively seek collaboration with researchers working in the field of denitrification.

Differences in Plant Traits among N-fixing Trees in Hawaii Affect Understory Nitrogen Cycling

NASA Astrophysics Data System (ADS)

August-Schmidt, E.; D'Antonio, C. M.

2016-12-01

Nitrogen (N) fixing trees are frequently used to restore soil functions to degraded ecosystems because they can increase soil organic matter and N availability. Although N-fixers are lumped into a single functional group, the quality and quantity of the plant material they produce and the rate at which they accrete and add N to the cycling pool likely vary. This talk will focus on the questions: (1) How does N-cycling differ among N-fixing tree species? And (2) Which plant traits are most important in distinguishing the soil N environment? To address these questions, we investigated planted stands of two Hawaiian native N-fixing trees (Acacia koa and Sophora chrysophylla) and `natural' stands of an invasive N-fixing tree (Morella faya) in burned seasonal submontane woodlands in Hawaii Volcanoes National Park. We measured the relative availability of nitrogen in the soil pool and understory plant community as well as characterizing the rate and amount of N cycling in these stands both in the field and using long term soil incubations in the laboratory. We found that N is cycled very differently under these three N-fixers and that this correlates with differences in their leaf traits. S. chrysophylla had the highest foliar %N and highest specific leaf area, and stands of these trees are associated with faster N-cycling, resulting in greater N availability compared to all other site types. Incubated S. chrysophylla soils mineralized almost twice as much N as any other soil type over the course of the experiment. The comparatively high-N environment under S. chrysophylla suggests that litter quality may be more important than litter quantity in determining nitrogen availability to the understory community.

Testing the Visual Soil Assessment tool on Estonian farm fields

NASA Astrophysics Data System (ADS)

Reintam, Endla; Are, Mihkel; Selge, Are

2017-04-01

Soil quality estimation plays important role in decision making on farm as well on policy level. Sustaining the production ability and good health of the soil the chemical, physical and biological indicators should be taken into account. The system to use soil chemical parameters is usually quite well established in most European counties, including Estonia. However, measuring soil physical properties, such bulk density, porosity, penetration resistance, structural stability ect is time consuming, needs special tools and is highly weather dependent. In that reason these parameters are excluded from controllable quality parameters in policy in Estonia. Within the project "Interactive Soil Quality Assessment in Europe and China for Agricultural Productivity and Environmental Resilience" (iSQAPER) the visual soil assessment (VSA) tool was developed for easy detection of soil quality as well the different soil friendly agricultural management practices (AMP) were detected. The aim of current study was to test the VSA tool on Estonian farm fields under different management practices and compare the results with laboratory measurements. The main focus was set on soil physical parameters. Next to the VSA, the undisturbed soil samples were collected from the depth of 5-10 cm and 25-30 cm. The study revealed that results of a visually assessed soil physical parameters, such a soil structure, soil structural stability, soil porosity, presence of tillage pan, were confirmed by laboratory measurements in most cases. Soil water stable structure measurement on field (on 1 cm2 net in one 1 l box with 4-6 cm air dry clods for 5-10 min) underestimated very well structured soil on grassland and overestimated the structure aggregates stability of compacted soil. The slightly better soil quality was detected under no-tillage compared to ploughed soils. However, the ploughed soil got higher quality points compared with minimum tillage. The slurry application (organic manuring) had controversial impact - it increased the number of earthworms but decreased soil structural stability. Even the manuring with slurry increases organic matter amount in the soil, the compaction due to the use of heavy machinery during the application, especially on wet soil, reduces the positive effect of slurry.

Biochar application for the remediation of salt-affected soils: Challenges and opportunities.

PubMed

Saifullah; Dahlawi, Saad; Naeem, Asif; Rengel, Zed; Naidu, Ravi

2018-06-01

Soil salinization and sodification are two commonly occurring major threats to soil productivity in arable croplands. Salt-affected soils are found in >100 countries, and their distribution is extensive and widespread in arid and semi-arid regions of the world. In order to meet the challenges of global food security, it is imperative to bring barren salt-affected soils under cultivation. Various inorganic and organic amendments are used to reclaim the salt-affected lands. The selection of a sustainable ameliorant is largely determined by the site-specific geographical and soil physicochemical parameters. Recently, biochar (solid carbonaceous residue, produced under oxygen-free or oxygen-limited conditions at temperatures ranging from 300 to 1000°C) has attracted considerable attention as a soil amendment. An emerging pool of knowledge shows that biochar addition is effective in improving physical, chemical and biological properties of salt-affected soils. However, some studies have also found an increase in soil salinity and sodicity with biochar application at high rates. Further, the high cost associated with production of biochar and high application rates remains a significant challenge to its widespread use in areas affected by salinity and sodicity. Moreover, there is relatively limited information on the long-term behavior of salt-affected soils subjected to biochar applications. The main objective of the present paper was to review, analyze and discuss the recent studies investigating a role of biochar in improving soil properties and plant growth in salt-affected soils. This review emphasizes that using biochar as an organic amendment for sustainable and profitable use of salt-affected soils would not be practicable as long as low-cost methods for the production of biochar are not devised. Copyright © 2017 Elsevier B.V. All rights reserved.

Palmarosa [Cymbopogon martinii (Roxb.) Wats.] as a putative crop for phytoremediation, in tannery sludge polluted soil.

PubMed

Pandey, Janhvi; Chand, Sukhmal; Pandey, Shipra; Rajkumari; Patra, D D

2015-12-01

A field experiment using tannery sludge as a soil amendment material and palmarosa (Cymbopogon martinii) as a potential phytostabilizer was conducted to investigate their synergistic effect in relation to the improvement in soil quality/property. Three consecutive harvests of two cultivars of palmarosa-PRC-1 and Trishna, were examined to find out the influence of different tannery sludge doses on their herb, dry matter, essential oil yield and heavy metal accumulation. Soil fertility parameters (N, P, K, Organic carbon) were markedly affected by different doses of sludge. Enhanced soil nitrogen was positively correlated with herb yield (0.719*) and plant height (0.797*). The highest dose of tannery sludge (100 t ha(-1)) exhibited best performance than other treatments with respect to herb, dry matter and oil yield in all three harvests. Trishna was found to be superior to PRC-1 in relation to same studied traits. Quality of oil varied, but was insignificant statistically. Uptake of heavy metals followed same order (Cr>Ni>Pb>Cd) in roots and shoots. Translocation factor <1 for all trace elements and Bioconcentration factor >1 was observed in case of all heavy metals. Overall, tannery sludge enhanced the productivity of crop and metal accumulation occurred in roots with a meager translocation to shoots, hence it can be used as a phytostabiliser. The major advantage of taking palmarosa in metal polluted soil is that unlike food and agricultural crops, the product (essential oil) is extracted by hydro-distillation and there is no chance of oil contamination, thus is commercially acceptable. Copyright © 2015 Elsevier Inc. All rights reserved.

Climate and litter quality differently modulate the effects of soil fauna on litter decomposition across biomes

PubMed Central

García-Palacios, Pablo; Maestre, Fernando T.; Kattge, Jens; Wall, Diana H.

2015-01-01

Climate and litter quality have been identified as major drivers of litter decomposition at large spatial scales. However, the role played by soil fauna remains largely unknown, despite its importance for litter fragmentation and microbial activity. We synthesized litterbag studies to quantify the effect sizes of soil fauna on litter decomposition rates at the global and biome scales, and to assess how climate, litter quality and soil fauna interact to determine such rates. Soil fauna consistently enhanced litter decomposition at both global and biome scales (average increment ~27%). However, climate and litter quality differently modulated the effects of soil fauna on decomposition rates between biomes, from climate-driven biomes to those where climate effects were mediated by changes in litter quality. Our results advocate for the inclusion of biome-specific soil fauna effects on litter decomposition as a mean to reduce the unexplained variation in large-scale decomposition models. PMID:23763716

Is the soil quality monitoring an effective tool in consumers' protection of agricultural crops from cadmium soil contamination?-a case of the Silesia region (Poland).

PubMed

Piekut, Agata; Baranowska, Renata; Marchwińska-Wyrwał, Ewa; Ćwieląg-Drabek, Małgorzata; Hajok, Ilona; Dziubanek, Grzegorz; Grochowska-Niedworok, Elżbieta

2017-12-16

The monitoring of soil quality should be a control tool used to reduce the adverse health effects arising from exposure to toxic chemicals in soil through cultivated crop absorption. The aim of the study was to evaluate the effectiveness of the monitoring and control system of soil quality in Poland, in terms of consumer safety, for agricultural plants cultivated in areas with known serious cadmium contamination, such as Silesia Province. To achieve the objective, the contents of cadmium in soils and vegetables in the Silesia administrative area were examined. The obtained results were compared with the results of soil contamination from the quality monitoring of arable soil in Poland. The studies show a significant exceedance of the permissible values of cadmium in soil samples and the vegetables cultivated on that soil. The threat to consumer health is a valid concern, although this threat was not indicated by the results of the national monitoring of soil quality. The results indicated an unequal distribution of risk to consumers resulting from contaminated soil. Moreover, the monitoring systems should be designed at the local or regional scale to guarantee the safety of consumers of edible plants cultivated in the areas contaminated with cadmium.

Current status, uncertainty and future needs in soil organic carbon monitoring.

PubMed

Jandl, Robert; Rodeghiero, Mirco; Martinez, Cristina; Cotrufo, M Francesca; Bampa, Francesca; van Wesemael, Bas; Harrison, Robert B; Guerrini, Iraê Amaral; Richter, Daniel Deb; Rustad, Lindsey; Lorenz, Klaus; Chabbi, Abad; Miglietta, Franco

2014-01-15

Increasing human demands on soil-derived ecosystem services requires reliable data on global soil resources for sustainable development. The soil organic carbon (SOC) pool is a key indicator of soil quality as it affects essential biological, chemical and physical soil functions such as nutrient cycling, pesticide and water retention, and soil structure maintenance. However, information on the SOC pool, and its temporal and spatial dynamics is unbalanced. Even in well-studied regions with a pronounced interest in environmental issues information on soil carbon (C) is inconsistent. Several activities for the compilation of global soil C data are under way. However, different approaches for soil sampling and chemical analyses make even regional comparisons highly uncertain. Often, the procedures used so far have not allowed the reliable estimation of the total SOC pool, partly because the available knowledge is focused on not clearly defined upper soil horizons and the contribution of subsoil to SOC stocks has been less considered. Even more difficult is quantifying SOC pool changes over time. SOC consists of variable amounts of labile and recalcitrant molecules of plant, and microbial and animal origin that are often operationally defined. A comprehensively active soil expert community needs to agree on protocols of soil surveying and lab procedures towards reliable SOC pool estimates. Already established long-term ecological research sites, where SOC changes are quantified and the underlying mechanisms are investigated, are potentially the backbones for regional, national, and international SOC monitoring programs. © 2013.

In Field Monitoring of Potential Detrimental Effects of Biofuels Production on Soil Quality

USDA-ARS?s Scientific Manuscript database

Soil organic carbon (SOC) content is recognized as a soil quality indicator that is susceptible to degradation with tillage and with biomass removal from the soil surface. In addition to reported benefits of leaving crop residue on the soil surface in preventing soil erosion, providing plant nutrien...

Soil microbial diversity and activity linked to crop yield and quality in a dryland organic wheat production system

USDA-ARS?s Scientific Manuscript database

One of the primary goals of organic agriculture is increasing soil quality through the enhancement of soil biological diversity and activity. Greater soil microbial activity and diversity increase soil organic matter turnover and contribute to soil fertility, one of the main challenges associated wi...

Impacts of biofuel expansion on soil quality and carbon dynamics in a central Iowa watershed

USDA-ARS?s Scientific Manuscript database

Crop residues (plant litter) on the soil surface helps decrease soil erosion, increase water infiltration, increase soil organic matter, and improve soil quality. Thus, management of crop residues is an integral part of most conservation tillage systems. Crop residue cover is used to classify soil t...

Effects of land disposal of municipal sewage sludge on fate of nitrates in soil, streambed sediment, and water quality

USGS Publications Warehouse

Tindall, James A.; Lull, Kenneth J.; Gaggiani, Neville G.

1994-01-01

This study was undertaken to determine the effects of sewage-sludge disposal at the Lowry sewage-sludge-disposal area, near Denver, Colorado, on ground- and surface-water quality, to determine the fate of nitrates from sludge leachate, and to determine the source areas of leachate and the potential for additional leaching from the disposal area.Sewage-sludge disposal began in 1969. Two methods were used to apply the sludge: burial and plowing. Also, the sludge was applied both in liquid and cake forms. Data in this report represent the chemical composition of soil and streambed sediment from seven soil- and four streambed-sampling sites in 1986, chemical and bacterial composition of ground water from 28 wells from 1981 to 1987, and surface-water runoff from seven water-sampling sites from 1984 to 1987. Ground water samples were obtained from alluvial and bedrock aquifers. Samples of soil, streambed sediment, ground water and surface water were obtained for onsite measurement and chemical analysis. Measurements included determination of nitrogen compounds and major cations and anions, fecal-coliform and -streptococcus bacteria, specific conductance, and pH.Thirteen wells in the alluvial aquifer in Region 3 of the study area contain water that was probably affected by sewage-sludge leachate. The plots of concentration of nitrate with time show seasonal trends and trends caused by precipitation. In addition to yearly fluctuation, there were noticeable increases in ground-water concentrations of nitrate that coincided with increased precipitation. After 3 years of annual ground-water-quality monitoring and 4 years of a quarterly sampling program, it has been determined that leachate from the sewage-sludge-disposal area caused increased nitrite plus nitrate (as nitrogen) concentration in the alluvial ground water at the site. Soil analyses from the disposal area indicate that organic nitrogen was the dominant form of nitrogen in the soil.As a result of investigations at the research site, it has been determined that a potentially large source of contamination exists in the soils of the study area owing to increased concentrations of nitrogen, sodium, calcium, magnesium, sulfate, bicarbonate, and chloride because of sewage disposal. Continued monitoring of surface and ground water for nitrogen and the other ions previously mentioned is required to assess long-term effects of municipal sludge disposal on water quality.

Effects of land disposal of municipal sewage sludge on fate of nitrates in soil, streambed sediment, and water quality

NASA Astrophysics Data System (ADS)

Tindall, James A.; Lull, Kenneth J.; Gaggiani, Neville G.

1994-12-01

This study was undertaken to determine the effects of sewage-sludge disposal at the Lowry sewage-sludge-disposal area, near Denver, Colorado, on ground- and surface-water quality, to determine the fate of nitrates from sludge leachate, and to determine the source areas of leachate and the potential for additional leaching from the disposal area. Sewage-sludge disposal began in 1969. Two methods were used to apply the sludge: burial and plowing. Also, the sludge was applied both in liquid and cake forms. Data in this report represent the chemical composition of soil and streambed sediment from seven soil- and four streambed-sampling sites in 1986, chemical and bacterial composition of ground water from 28 wells from 1981 to 1987, and surface-water runoff from seven water-sampling sites from 1984 to 1987. Ground water samples were obtained from alluvial and bedrock aquifers. Samples of soil, streambed sediment, ground water and surface water were obtained for onsite measurement and chemical analysis. Measurements included determination of nitrogen compounds and major cations and anions, fecal-coliform and -streptococcus bacteria, specific conductance, and pH. Thirteen wells in the alluvial aquifer in Region 3 of the study area contain water that was probably affected by sewage-sludge leachate. The plots of concentration of nitrate with time show seasonal trends and trends caused by precipitation. In addition to yearly fluctuation, there were noticeable increases in ground-water concentrations of nitrate that coincided with increased precipitation. After 3 years of annual ground-water-quality monitoring and 4 years of a quarterly sampling program, it has been determined that leachate from the sewage-sludge-disposal area caused increased nitrite plus nitrate (as nitrogen) concentration in the alluvial ground water at the site. Soil analyses from the disposal area indicate that organic nitrogen was the dominant form of nitrogen in the soil. As a result of investigations at the research site, it has been determined that a potentially large source of contamination exists in the soils of the study area owing to increased concentrations of nitrogen, sodium, calcium, magnesium, sulfate, bicarbonate, and chloride because of sewage disposal. Continued monitoring of surface and ground water for nitrogen and the other ions previously mentioned is required to assess long-term effects of municipal sludge disposal on water quality.

Soil quality: Some basic considerations and case studies

Treesearch

Dale W. Johnson

2010-01-01

Some fundamental properties of soils that pertain to the concept of soil quality are discussed including a discussion of what can and cannot be changed with management.Case studies showing the effects of N-fixing vegetation and N-enrichment effects on invasive species are provided to illustrate the complications that may arise from applying one soil quality standard to...

Effects of Grazing and Fire Frequency on Floristic Quality and its Relationship to Indicators of Soil Quality in Tallgrass Prairie

NASA Astrophysics Data System (ADS)

Manning, George C.; Baer, Sara G.; Blair, John M.

2017-12-01

Fire and grazing are widely used to manage grasslands for conservation purposes, but few studies have evaluated the effects of these drivers on the conservation value of plant communities measured by the floristic quality index (FQI). Further, the influence of fire and grazing on soil properties and functions are difficult for land managers and restoration practitioners to assess. The objectives of this study were to: (1) quantify the independent and interactive effects of grazing and fire frequency on floristic quality in native tallgrass prairie to provide potential benchmarks for community assessment, and (2) to explore whether floristic quality can serve as an indicator of soil structure and function for more holistic ecosystem assessments. A factorial combination of fire frequencies (1-2, 4, and 20 years return intervals) and grazing (by bison or ungrazed) treatments were sampled for plant species composition, and for several indicators of soil quality in lowland tallgrass prairie. Floristic quality, diversity, and richness were higher in grazed than ungrazed prairie over all fire frequencies ( P < 0.05). Available inorganic N, microbial biomass N, total N, and soil bulk density were also higher in grazed prairie soil over all fire frequencies ( P < 0.05). Microbial biomass C, total organic C, and total soil N were positively correlated with FQI ( P < 0.05). This study shows that floristic quality and soil N pools are more strongly influenced by grazing than fire and that floristic quality can be an indicator of total soil C and N stocks in never cultivated lowland prairie.

Effects of Grazing and Fire Frequency on Floristic Quality and its Relationship to Indicators of Soil Quality in Tallgrass Prairie.

PubMed

Manning, George C; Baer, Sara G; Blair, John M

2017-12-01

Fire and grazing are widely used to manage grasslands for conservation purposes, but few studies have evaluated the effects of these drivers on the conservation value of plant communities measured by the floristic quality index (FQI). Further, the influence of fire and grazing on soil properties and functions are difficult for land managers and restoration practitioners to assess. The objectives of this study were to: (1) quantify the independent and interactive effects of grazing and fire frequency on floristic quality in native tallgrass prairie to provide potential benchmarks for community assessment, and (2) to explore whether floristic quality can serve as an indicator of soil structure and function for more holistic ecosystem assessments. A factorial combination of fire frequencies (1-2, 4, and 20 years return intervals) and grazing (by bison or ungrazed) treatments were sampled for plant species composition, and for several indicators of soil quality in lowland tallgrass prairie. Floristic quality, diversity, and richness were higher in grazed than ungrazed prairie over all fire frequencies (P < 0.05). Available inorganic N, microbial biomass N, total N, and soil bulk density were also higher in grazed prairie soil over all fire frequencies (P < 0.05). Microbial biomass C, total organic C, and total soil N were positively correlated with FQI (P < 0.05). This study shows that floristic quality and soil N pools are more strongly influenced by grazing than fire and that floristic quality can be an indicator of total soil C and N stocks in never cultivated lowland prairie.

Habitat management affects soil chemistry and allochthonous organic inputs mediating microbial structure and exo-enzyme activity in Wadden Sea salt-marsh soils

NASA Astrophysics Data System (ADS)

Mueller, Peter; Granse, Dirk; Thi Do, Hai; Weingartner, Magdalena; Nolte, Stefanie; Hoth, Stefan; Jensen, Kai

2016-04-01

The Wadden Sea (WS) region is Europe's largest wetland and home to approximately 20% of its salt marsh area. Mainland salt marshes of the WS are anthropogenically influenced systems and have traditionally been used for livestock grazing in wide parts. After foundation of WS National Parks in the late 1980s and early 1990s, artificial drainage has been abandoned; however, livestock grazing is still common in many areas of the National Parks and is under ongoing discussion as a habitat-management practice. While studies so far focused on effects of livestock grazing on biodiversity, little is known about how biogeochemical processes, element cycling, and particularly carbon sequestration are affected. Here, we present data from a recent field study focusing on grazing effects on soil properties, microbial exo-enzyme activity, microbial abundance and structure. Exo-enzyme activity was studied conducting digestive enzyme assays for various enzymes involved in C- and N cycling. Microbial abundance and structure was assessed measuring specific gene abundance of fungi and bacteria using quantitative PCR. Soil compaction induced by grazing led to higher bulk density and decreases in soil redox (Δ >100 mV). Soil pH was significantly lower in grazed parts. Further, the proportion of allochthonous organic matter (marine input) was significantly smaller in grazed vs. ungrazed sites, likely caused by a higher sediment trapping capacity of the taller vegetation in the ungrazed sites. Grazing induced changes in bulk density, pH and redox resulted in reduced activity of enzymes involved in microbial C acquisition; however, there was no grazing effect on enzymes involved in N acquisition. While changes in pH, bulk density or redox did not affect microbial abundance and structure, the relative amount of marine organic matter significantly reduced the relative abundance of fungi (F:B ratio). We conclude that livestock grazing directly affects microbial exo-enzyme activity, thus slowing down C turnover, and indirectly changes microbial structure, namely relative fungal abundance, by reducing high-quality marine organic matter inputs.

Long-term Effect of Pig Slurry Application on Soil Carbon Storage, Quality and Yield Sustainability in Murcia Region, Spain

NASA Astrophysics Data System (ADS)

Büyükkılıç Yanardaǧ, Asuman

2013-04-01

Sustainability of agriculture is now a major global concern, especially since the 1980s. Soil organic matter is very important in the proper functions of the soil, which is also a good indicator of soil quality. This is due to its influence on many of the chemical, physical, and biological processes that control the capacity of a soil to perform properly. Understanding of nutrient supply through organic matter mineralization in agricultural systems is essential for maintaining long-term quality and productivity. The composition of pig manure will have a profound impact on soil properties, quality and crop yield when used in agriculture. We studied the effects of pig slurry (PS) application as an organic fertilizer, trying to determine the optimum amount that can be added to the soil, and the effect on soil properties, quality, and productivity. We applied 3 different doses on silty loam soils: Single (D1), Double (D2), Triple (D3) and unfertilized plots (C) served as controls. Samples were collected at two different levels, surface (0-30 cm) and subsurface (30-60 cm). D1 application dose, which is the agronomic rate of N-requirement (170 kg N/ha/yr) (European Directive 91/676/CEE), is very appropriate in term of sustainable agriculture and also can improve physical, chemical and biological soil properties. Therefore that the long-term use of PS with low dose may necessarily enhance soil quality in the long term. There are many factors to be considered when attempting to assess the overall net impact of a management practice on productivity. Additions of pig manure to soils at agronomic rates (170 kg N ha-1 yr-1) to match crop nutrient requirements are expected to have a positive impact on soil productivity. Therefore, the benefits from the use of application depend on the management of PS, carbon and environmental quality. However, PS have high micronutrient contents, and for this reason the application of high doses can pollute soils and damage human, animal and plant health, which is not suitable in term of sustainable agriculture. Keywords: Management, Pig slurry, Productivity, Quality, Soil.

Does drought alter hydrological functions in forest soils? An infiltration experiment

NASA Astrophysics Data System (ADS)

Gimbel, K. F.; Puhlmann, H.; Weiler, M.

2015-08-01

The water cycle is expected to change in future and severely affect precipitation patterns across central Europe and in other parts of the world, leading to more frequent and severe droughts. Usually, it is assumed that system properties, like soil properties, remain stable and will not be affected by drought events. To study if this assumption is appropriate, we address the effects of drought on the infiltration behavior of forest soils using dye tracer experiments on six sites in three regions across Germany, which were forced into drought conditions. The sites cover clayey, loamy and sandy textured soils. In each region, we compared a deciduous and a coniferous forest stand to address differences between the main tree species. The results of the dye tracer experiments show clear evidence for changes in infiltration behavior at the sites. The infiltration changed at the clayey plots from regular and homogeneous flow to fast preferential flow. Similar behavior was observed at the loamy plots, where large areas in the upper layers remained dry, displaying signs of strong water repellency. This was confirmed by WDPT tests, which revealed, in all except one plot, moderate to severe water repellency. Water repellency was also accountable for the change of regular infiltration to fingered flow in the sandy soils. The results of this study suggest that the "drought-history" or generally the climatic conditions in the past of a soil are more important than the actual antecedent soil moisture status regarding hydrophobicity and infiltration behavior; and also, that drought effects on infiltration need to be considered in hydrological models to obtain realistic predictions concerning water quality and quantity in runoff and groundwater recharge.

Does drought alter hydrological functions in forest soils?

NASA Astrophysics Data System (ADS)

Gimbel, Katharina F.; Puhlmann, Heike; Weiler, Markus

2016-04-01

Climate change is expected to impact the water cycle and severely affect precipitation patterns across central Europe and in other parts of the world, leading to more frequent and severe droughts. Usually when projecting drought impacts on hydrological systems, it is assumed that system properties, like soil properties, remain stable and will not be affected by drought events. To study if this assumption is appropriate, we address the effects of drought on the infiltration behavior of forest soils using dye tracer experiments on six sites in three regions across Germany, which were forced into drought conditions. The sites cover clayey-, loamy- and sandy-textured soils. In each region, we compared a deciduous and a coniferous forest stand to address differences between the main tree species. The results of the dye tracer experiments show clear evidence for changes in infiltration behavior at the sites. The infiltration changed at the clayey plots from regular and homogeneous flow to fast preferential flow. Similar behavior was observed at the loamy plots, where large areas in the upper layers remained dry, displaying signs of strong water repellency. This was confirmed by water drop penetration time (WDPT) tests, which revealed, in all except one plot, moderate to severe water repellency. Water repellency was also accountable for the change of regular infiltration to fingered flow in the sandy soils. The results of this study suggest that the drought history or, more generally, the climatic conditions of a soil in the past are more important than the actual antecedent soil moisture status regarding hydrophobicity and infiltration behavior; furthermore, drought effects on infiltration need to be considered in hydrological models to obtain realistic predictions concerning water quality and quantity in runoff and groundwater recharge.

Effects of organic and conventional management of sugar cane crop on soil physicochemical characteristics and phosphomonoesterase activity.

PubMed

Purcena, Luiza L A; Di Medeiros, Maria Carolina B; Leandro, Wilson M; Fernandes, Kátia F

2014-02-19

Soil enzymes play an important role in agriculture and particularly in nutrient cycling. They are also involved in the degradation, transformation, and mineralization of organic matter and availability of nutrients in soil. It is believed that organic agriculture causes fewer losses to soil quality and is less aggressive to the environment than conventional management. In this study, the effects of conventional (CM) and organic management (OM) on phosphomonoesterases, an important enzyme for soil fertility, were evaluated and compared to those results from native Cerrado (Brazilian Savanna) soil (NS), because they are the most common phosphatases in soils. The results showed that there were both acid (AcP) and alkaline (AkP) phosphatases in all soils tested and that AcP activity was higher than that of AkP. In contrast to AkP, AcP had its activity affected by land use. In the cultivated areas there was a reduction of almost 50% of AcP activity respect to native unexploited soils and there was no significant difference between organic and CM, demonstrating that independent of the management chosen, there was an impact of land use on AcP activity. Principal component analysis indicated that characteristics related to pH such as alkali saturation (V%), aluminum saturation (M%), Al(3+), soil total acidity (H+Al), and Ca(2+) are the main factors that permit distinguishing NS from OM and CM.

Can Tomato Inoculation with Trichoderma Compensate Yield and Soil Health Deficiency due to Soil Salinity?

NASA Astrophysics Data System (ADS)

Wagner, Karl; Apostolakis, Antonios; Daliakopoulos, Ioannis; Tsanis, Ioannis

2016-04-01

Soil salinity is a major soil degradation threat, especially for arid coastal environments where it hinders agricultural production and soil health. Protected horticultural crops in the Mediterranean region, typically under deficit irrigation and intensive cultivation practices, have to cope with increasing irrigation water and soil salinization. This study quantifies the beneficial effects of the Trichoderma harzianum (TH) on the sustainable production of Solanum lycopersicum (tomato), a major greenhouse crop of the RECARE project Case Study in Greece, the semi-arid coastal Timpaki basin in south-central Crete. 20 vigorous 20-day-old Solanum lycopersicum L. cv Elpida seedlings are treated with TH fungi (T) or without (N) and transplanted into 35 L pots under greenhouse conditions. Use of local planting soil with initial Electrical Conductivity (ECe) 1.8 dS m-1 and local cultivation practices aim to simulate the prevailing conditions at the Case Study. In order to simulate seawater intrusion affected irrigation, plants are drip irrigated with two NaCl treatments: slightly (S) saline (ECw = 1.1 dS m-1) and moderately (M) saline water (ECw = 3.5 dS m-1), resulting to very high and excessively high ECe, respectively. Preliminary analysis of below and aboveground biomass, soil quality, salinity, and biodiversity indicators, suggest that TH pre-inoculation of tomato plants at both S and M treatments improve yield, soil biodiversity and overall soil health.

Rapid in situ assessment for predicting soil quality using an algae-soaked disc seeding assay.

PubMed

Nam, Sun-Hwa; Moon, Jongmin; Kim, Shin Woong; Kim, Hakyeong; Jeong, Seung-Woo; An, Youn-Joo

2017-11-16

The soil quality of remediated land is altered and this land consequently exerts unexpected biological effects on terrestrial organisms. Therefore, field evaluation of such land should be conducted using biological indicators. Algae are a promising new biological indicator since they are a food source for organisms in higher soil trophic levels and easily sampled from the soil. Field evaluation of soil characteristics is preferred to be testing in laboratory conditions because many biological effects cannot be duplicated during laboratory evaluations. Herein, we describe a convenient and rapid algae-soaked disc seeding assay for assessing soil quality in the field based on soil algae. The collection of algae is easy and rapid and the method predicts the short-term quality of contaminated, remediated, and amended farm and paddy soils. The algae-soaked disc seeding assay is yet to be extensively evaluated, and the method cannot be applied to loamy sand soil in in situ evaluations. The algae-soaked disc seeding assay is recommended for prediction of soil quality in in situ evaluations because it reflects all variations in the environment. The algae-soaked disc seeding assay will help to develop management strategies for in situ evaluation.

Impact of ecosystem management on microbial community level physiological profiles of postmining forest rehabilitation.

PubMed

Cookson, W R; O'Donnell, A J; Grant, C D; Grierson, P F; Murphy, D V

2008-02-01

We investigated the impacts of forest thinning, prescribed fire, and contour ripping on community level physiological profiles (CLPP) of the soil microbial population in postmining forest rehabilitation. We hypothesized that these management practices would affect CLPP via an influence on the quality and quantity of soil organic matter. The study site was an area of Jarrah (Eucalyptus marginata Donn ex Sm.) forest rehabilitation that had been mined for bauxite 12 years previously. Three replicate plots (20 x 20 m) were established in nontreated forest and in forest thinned from 3,000-8,000 stems ha(-1) to 600-800 stems ha(-1) in April (autumn) of 2003, followed either by a prescribed fire in September (spring) of 2003 or left nonburned. Soil samples were collected in August 2004 from two soil depths (0-5 cm and 5-10 cm) and from within mounds and furrows caused by postmining contour ripping. CLPP were not affected by prescribed fire, although the soil pH and organic carbon (C), total C and total nitrogen (N) contents were greater in burned compared with nonburned plots, and the coarse and fine litter mass lower. However, CLPP were affected by forest thinning, as were fine litter mass, soil C/N ratio, and soil pH, which were all higher in thinned than nonthinned plots. Furrow soil had greater coarse and fine litter mass, and inorganic phosphorous (P), organic P, organic C, total C, total N, ammonium, microbial biomass C contents, but lower soil pH and soil C/N ratio than mound soil. Soil pH, inorganic P, organic P, organic C, total C and N, ammonium, and microbial biomass C contents also decreased with depth, whereas soil C/N ratio increased. Differences in CLPP were largely (94%) associated with the relative utilization of gluconic, malic (greater in nonthinned than thinned soil and mound than furrow soil), L-tartaric, succinic, and uric acids (greater in thinned than nonthinned, mound than furrow, and 5-10 cm than 0-5 cm soil). The relative utilization of amino acids also tended to increase with increasing soil total C and organic C contents but decreased with increasing nitrate content, whereas the opposite was true for carboxylic acids. Only 45% of the variance in CLPP was explained using a multivariate multiple regression model, but soil C and N pools and litter mass were significant predictors of CLPP. Differences in soil textural components between treatments were also correlated with CLPP; likely causes of these differences are discussed. Our results suggest that 1 year after treatment, CLPP from this mined forest ecosystem are resilient to a spring prescribed fire but not forest thinning. We conclude that differences in CLPP are likely to result from complex interactions among soil properties that mediate substrate availability, microbial nutrient demand, and microbial community composition.

Impact of naturally leaking carbon dioxide on soil properties and ecosystems in the Qinghai-Tibet plateau.

PubMed

Zhao, Xiaohong; Deng, Hongzhang; Wang, Wenke; Han, Feng; Li, Chunrong; Zhang, Hui; Dai, Zhenxue

2017-06-07

One of the major concerns for CO 2 capture and storage (CCS) is the potential risk of CO 2 leakage from storage reservoirs on the shallow soil property and vegetation. This study utilizes a naturally occurring CO 2 leaking site in the Qinghai-Tibet Plateau to analog a "leaking CCS site". Our observations from this site indicates that long-term CO 2 invasion in the vadose zone results in variations of soil properties, such as pH fluctuation, slight drop of total organic carbon, reduction of nitrogen and phosphorus, and concentration changes of soluble ions. Simultaneously, XRD patterns of the soil suggest that crystallization of soil is enhanced and mineral contents of calcite and anorthite in soil are increased substantially. Parts of the whole ecosystem such as natural wild plants, soil dwelling animals and microorganisms in shallow soil are affected as well. Under a moderate CO 2 concentration (less than 110000 ppm), wild plant growth and development are improved, while an intensive CO 2 flux over 112000 ppm causes adverse effects on the plant growth, physiological and biochemical system of plants, and crop quality of wheat. Results of this study provide valuable insight for understanding the possible environmental impacts associated with potential CO 2 leakage into shallow sediments at carbon sequestration sites.

Root chemistry and soil fauna, but not soil abiotic conditions explain the effects of plant diversity on root decomposition.

PubMed

Chen, Hongmei; Oram, Natalie J; Barry, Kathryn E; Mommer, Liesje; van Ruijven, Jasper; de Kroon, Hans; Ebeling, Anne; Eisenhauer, Nico; Fischer, Christine; Gleixner, Gerd; Gessler, Arthur; González Macé, Odette; Hacker, Nina; Hildebrandt, Anke; Lange, Markus; Scherer-Lorenzen, Michael; Scheu, Stefan; Oelmann, Yvonne; Wagg, Cameron; Wilcke, Wolfgang; Wirth, Christian; Weigelt, Alexandra

2017-11-01

Plant diversity influences many ecosystem functions including root decomposition. However, due to the presence of multiple pathways via which plant diversity may affect root decomposition, our mechanistic understanding of their relationships is limited. In a grassland biodiversity experiment, we simultaneously assessed the effects of three pathways-root litter quality, soil biota, and soil abiotic conditions-on the relationships between plant diversity (in terms of species richness and the presence/absence of grasses and legumes) and root decomposition using structural equation modeling. Our final structural equation model explained 70% of the variation in root mass loss. However, different measures of plant diversity included in our model operated via different pathways to alter root mass loss. Plant species richness had a negative effect on root mass loss. This was partially due to increased Oribatida abundance, but was weakened by enhanced root potassium (K) concentration in more diverse mixtures. Equally, grass presence negatively affected root mass loss. This effect of grasses was mostly mediated via increased root lignin concentration and supported via increased Oribatida abundance and decreased root K concentration. In contrast, legume presence showed a net positive effect on root mass loss via decreased root lignin concentration and increased root magnesium concentration, both of which led to enhanced root mass loss. Overall, the different measures of plant diversity had contrasting effects on root decomposition. Furthermore, we found that root chemistry and soil biota but not root morphology or soil abiotic conditions mediated these effects of plant diversity on root decomposition.

Consequences of varied soil hydraulic and meteorological complexity on unsaturated zone time lag estimates.

PubMed

Vero, S E; Ibrahim, T G; Creamer, R E; Grant, J; Healy, M G; Henry, T; Kramers, G; Richards, K G; Fenton, O

2014-12-01

The true efficacy of a programme of agricultural mitigation measures within a catchment to improve water quality can be determined only after a certain hydrologic time lag period (subsequent to implementation) has elapsed. As the biophysical response to policy is not synchronous, accurate estimates of total time lag (unsaturated and saturated) become critical to manage the expectations of policy makers. The estimation of the vertical unsaturated zone component of time lag is vital as it indicates early trends (initial breakthrough), bulk (centre of mass) and total (Exit) travel times. Typically, estimation of time lag through the unsaturated zone is poor, due to the lack of site specific soil physical data, or by assuming saturated conditions. Numerical models (e.g. Hydrus 1D) enable estimates of time lag with varied levels of input data. The current study examines the consequences of varied soil hydraulic and meteorological complexity on unsaturated zone time lag estimates using simulated and actual soil profiles. Results indicated that: greater temporal resolution (from daily to hourly) of meteorological data was more critical as the saturated hydraulic conductivity of the soil decreased; high clay content soils failed to converge reflecting prevalence of lateral component as a contaminant pathway; elucidation of soil hydraulic properties was influenced by the complexity of soil physical data employed (textural menu, ROSETTA, full and partial soil water characteristic curves), which consequently affected time lag ranges; as the importance of the unsaturated zone increases with respect to total travel times the requirements for high complexity/resolution input data become greater. The methodology presented herein demonstrates that decisions made regarding input data and landscape position will have consequences for the estimated range of vertical travel times. Insufficiencies or inaccuracies regarding such input data can therefore mislead policy makers regarding the achievability of water quality targets. Copyright © 2014 Elsevier B.V. All rights reserved.

Urbanization and nutrient retention in freshwater riparian wetlands

USGS Publications Warehouse

Hogan, D.M.; Walbridge, M.R.

2007-01-01

Urbanization can degrade water quality and alter watershed hydrology, with profound effects on the structure and function of both riparian wetlands (RWs) and aquatic ecosystems downstream. We used freshwater RWs in Fairfax County, Virginia, USA, as a model system to examine: (1) the effects of increasing urbanization (indexed by the percentage of impervious surface cover [%ISC] in the surrounding watershed) on nitrogen (N) and phosphorus (P) concentrations in surface soils and plant tissues, soil P saturation, and soil iron (Fe) chemistry; and (2) relationships between RW soil and plant nutrient chemistries vs. the physical and biotic integrity of adjacent streams. Soil total P and NaOH-extractable P (representing P bound to aluminum [Al] and Fe hydrous oxides) varied significantly but nonlinearly with %ISC (r2 = 0.69 and 0.57, respectively); a similar pattern was found for soil P saturation but not for soil total N. Relationships were best described by second-order polynomial equations. Riparian wetlands appear to receive greater P loads in moderately (8.6-13.3% ISC) than in highly (25.1-29.1% ISC) urbanized watersheds. These observations are consistent with alterations in watershed hydrology that occur with increasing urbanization, directing water and nutrient flows away from natural RWs. Significant increases in total and crystalline soil Fe (r 2 = 0.57 and 0.53, respectively) and decreases in relative soil Fe crystallinity with increasing %ISC suggest the mobilization and deposition of terrestrial sediments in RWs, likely due to construction activities in the surrounding watershed. Increases in RW plant tissue nutrient concentrations and %ISC in the surrounding watershed were negatively correlated with standard indices of the physical and biotic integrity of adjacent streams. In combination, these data suggest that nutrient and sediment inputs associated with urbanization and storm-water management are important variables that affect wetland ecosystem services, such as water quality improvement, in urbanizing landscapes. ?? 2007 by the Ecological Society of America.

Blackbird Creek Monitoring Program to Study the impact of Climate Change and Land Use

NASA Astrophysics Data System (ADS)

Ozbay, G.; Chintapenta, L. K.; Roeske, K. P.; Stone, M.; Phalen, L.

2014-12-01

The Blackbird Creek Monitoring Program at Delaware State University continues to utilize various perspectives to study the dynamics of one of Delaware's most pristine ecosystems. The water quality of Blackbird Creek has been constantly monitored for 3 years and correlated with the rain and storm events. Soil nutrients composition has been studied by extracting the water associated with soil aggregates and analyzing the levels of different nutrients. Soil quality is also assessed for heavy metals to identify potential human impact that may affect the health of ecosystem. Within the Blackbird Creek there is a threat to native plant communities from invasive plant species as they alter the ecosystem dynamics. Saltmarsh cord grass (Spartina alterniflora) and common reed (Phragmites australius) are the common wetland plants. Aerial mapping of the creek has been conducted to determine the area covered by invasive plant species. The microbial community structure plays a key role in soil carbon and nitrogen cycles in the ecosystem. Molecular analysis has been performed to study the microbial diversity with respect to the type of marsh grasses. This program has also incorporated the use of diatoms as biological indicators to assess the health of ecosystem and correlate that data with physical and chemical water quality data. The abundance and diversity of macro fauna such as blue crabs, fish and other significant species has also been studied. Stable isotopic analysis of these macro fauna has also been performed to study the food web. The results from this program will be helpful in addressing environmental challenges and designing management strategies.

An image analysis of TLC patterns for quality control of saffron based on soil salinity effect: A strategy for data (pre)-processing.

PubMed

Sereshti, Hassan; Poursorkh, Zahra; Aliakbarzadeh, Ghazaleh; Zarre, Shahin; Ataolahi, Sahar

2018-01-15

Quality of saffron, a valuable food additive, could considerably affect the consumers' health. In this work, a novel preprocessing strategy for image analysis of saffron thin layer chromatographic (TLC) patterns was introduced. This includes performing a series of image pre-processing techniques on TLC images such as compression, inversion, elimination of general baseline (using asymmetric least squares (AsLS)), removing spots shift and concavity (by correlation optimization warping (COW)), and finally conversion to RGB chromatograms. Subsequently, an unsupervised multivariate data analysis including principal component analysis (PCA) and k-means clustering was utilized to investigate the soil salinity effect, as a cultivation parameter, on saffron TLC patterns. This method was used as a rapid and simple technique to obtain the chemical fingerprints of saffron TLC images. Finally, the separated TLC spots were chemically identified using high-performance liquid chromatography-diode array detection (HPLC-DAD). Accordingly, the saffron quality from different areas of Iran was evaluated and classified. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of Forest Harvesting on Ecosystem Health in the Headwaters of the New York City Water Supply, Catskill Mountains, New York

USGS Publications Warehouse

McHale, Michael R.; Murdoch, Peter S.; Burns, Douglas A.; Baldigo, Barry P.

2008-01-01

The effects of forest clearcutting and selective harvesting on forest soils, soil and stream water chemistry, forest regrowth, and aquatic communities were studied in four small headwater catchments. This research was conducted to identify the sensitivity of forested ecosystems to forest disturbance in the northeastern United States. The study area was in the headwaters of the Neversink Reservoir watershed, part of the New York City water supply system, in the Catskill Mountains of southeastern New York. Two sub-catchments of the Shelter Creek watershed were selectively harvested, one in its northern half and one more heavily in its southern half in 1995?96, the Dry Creek watershed was clearcut in the winter of 1996?97, and the Clear Creek watershed was left undisturbed and monitored as a control site. Monitoring was conducted from 4 years before the harvests until 4 years after the harvests. Clearcutting caused a large release of nitrate (NO3-) from watershed soils and a concurrent release of inorganic monomeric aluminum (Alim), which is toxic to some aquatic biota. The increased soil NO3- concentrations measured after the harvest could be completely accounted for by the decrease in nitrogen (N) uptake by watershed trees, rather than an increase in N mineralization and nitrification. The large increase in stream water NO3- and Alim concentrations caused 100-percent mortality of caged brook trout (Salvelinus fontinalis) during the first year after the clearcut and adversely affected macroinvertebrate communities for 2 years after the harvest. Nutrient uptake and biomass accumulation increased in uncut mature trees after the two selective harvests. There was no increase in stream-water NO3- or Alim concentrations, and so there were no adverse affects on macroinvertebrate or trout communities. The amount of tree biomass that can be removed without causing a sharp increase in stream-water NO3- and Alim stream-water concentrations is unknown, but probably depends on the history of forest-disturbance and acid deposition and the level of soil acidification. Results of this study indicate that macroinvertebrate and brook trout communities were sensitive to clearcutting and that deer browsing may affect water quality by suppressing forest regeneration and nutrient uptake. Further studies of selective harvests could identify the harvesting threshold below which changes in water quality and soil chemistry are minimized, and nutrient retention is maximized, thus reducing the damage that logging can inflict on stream and aquatic communities.

Land use impact on soil quality in eastern Himalayan region of India.

PubMed

Singh, A K; Bordoloi, L J; Kumar, Manoj; Hazarika, S; Parmar, Brajendra

2014-04-01

Quantitative assessment of soil quality is required to determine the sustainability of land uses in terms of environmental quality and plant productivity. Our objective was to identify the most appropriate soil quality indicators and to evaluate the impact of six most prevalent land use types (natural forestland, cultivated lowland, cultivated upland terrace, shifting cultivation, plantation land, and grassland) on soil quality in eastern Himalayan region of India. We collected 120 soil samples (20 cm depth) and analyzed them for 29 physical, chemical, and biological soil attributes. For selection of soil quality indicators, principal component analysis (PCA) was performed on the measured attributes, which provided four principal components (PC) with eigenvalues >1 and explaining at least 5% of the variance in dataset. The four PCs together explained 92.6% of the total variance. Based on rotated factor loadings of soil attributes, selected indicators were: soil organic carbon (SOC) from PC-1, exchangeable Al from PC-2, silt content from PC-3, and available P and Mn from PC-4. Indicators were transformed into scores (linear scoring method) and soil quality index (SQI) was determined, on a scale of 0-1, using the weighting factors obtained from PCA. SQI rating was the highest for the least-disturbed sites, i.e., natural forestland (0.93) and grassland (0.87), and the lowest for the most intensively cultivated site, i.e., cultivated upland terrace (0.44). Ratings for the other land uses were shifting cultivation (0.60) > cultivated low land (0.57) > plantation land (0.54). Overall contribution (in percent) of the indicators in determination of SQI was in the order: SOC (58%) > exch. Al (17.1%) > available P (8.9%) > available Mn (8.2%) > silt content (7.8%). Results of this study suggest SOC and exch. Al as the two most powerful indicators of soil quality in study area. Thus, organic C and soil acidity management holds the key to improve soil quality under many exploitatively cultivated land use systems in eastern Himalayan region of India.

Woodland clearance alters geomorphic, hydrologic, and pedogenic drivers of ecosystem services: examples from the southern Blue Ridge (USA) and the French western Pyrenees Mountains

NASA Astrophysics Data System (ADS)

Leigh, David

2016-04-01

The southern Blue Ridge (USA) and French western Pyrenees both are humid-temperate mountains where native woodlands have been cleared on soils formed in residuum and colluvium on hillslopes. Forest removal increased rates of erosion and sediment yield that drove both negative and positive ecosystem services. For example, the supportive ecosystem service of soil formation was diminished on eroded hillslopes, but may have been enhanced by accumulation of sediment on bottomlands far downstream from the highland source areas. Negative effects on provisional ecosystem services (e.g. water supply) resulted in aggraded bottomlands by increasing the depth to the water table. Legacy effects linger on hillslopes that reforested (diminished soil properties), and ongoing alteration of pedogenic and hydrologic processes affect pastures that persisted from cleared woodlands. Beyond those general similarities, pastures of the two regions exhibit very different pedogenic pathways and ecosystem service outcomes. Soils of the Blue Ridge pastures adhere to a typical degradation scenario of erosion, compaction, and reduced infiltration capacities, whereas Pyrenees pastures exhibit soil qualities trending in the opposite direction and arguably now are better quality soils than their forested predecessors. Major differences in temporal duration and management styles apparently have led to such contrasts in soil quality. The Blue Ridge pastures are only tens to hundreds of years old, whereas Pyrenees pastures are thousands of years old. Blue Ridge pastures are maintained by mowing with tractors and year-round grazing primarily with beef cattle, whereas Pyrenees pastures (outfields) lack tractors and are only grazed seasonally (summer), primarily with sheep. Fire is rarely used as a management tool in the Blue Ridge, while Pyrenees pastures frequently are burned. Such management practices, and their influence on pedogenic and hydrologic processes, generally have resulted in negative ecosystem services in the Blue Ridge (degraded soils and water holding capacity) versus some positive ecosystem services in the Pyrenees. That is, the soils of the Pyrenees pastures store more carbon and provide equal or better water infiltration and storage capacity than their native forested predecessors, while that is not the case in the Blue Ridge. Stratigraphic proxies from colluvial deposits in the Pyrenees attest to a past when the management practices were erosional and degradational, (within the Bronze Age through Roman times), but more recent management practices appear to be sustainable and have resulted in improved soil quality. Both mountain ranges share some negative impacts, but the Pyrenees offer an example of anthropic landscape conversion where certain pedogenic and hydrologic processes have been enhanced and result in some positive ecosystem services and sustainable outcomes.

Mobilization of dissolved organic matter from soils and sediments impacted by thermal processes

NASA Astrophysics Data System (ADS)

Rosario-Ortiz, F.; Webster, J.; Retuta, A.; Borch, T.; Young, R. B.

2016-12-01

The frequency and intensity of wildfires has increased in recent decades and this trend is expected to continue for the foreseeable future. Global climate change is predicted to result in the persistence of warmer and drier conditions, leading to an increase in fire frequency, fire season duration, and fire-impacted area. This trend has specifically been observable in the Western United States. The impacts on forested watersheds and the high quality drinking water these forests provide are still relatively uncharacterized and elucidation is needed to adapt treatment strategies as wildfire frequency increases. One main concern is an increase in the mobilization of dissolved organic matter (DOM). Furthermore, there is paucity of information regarding how an altered landscape from wildland fires affects the physical and chemical properties of the DOM, which may adjust the mechanisms that control DOM release and ultimately lead to changes in treatment efficacy. Investigating these parameters may help to explain why this concentration has been observed to increase. Because DOM supplies the precursors for disinfection byproduct formation during drinking water treatment, such differences could affect drinking water quality and public health. In this work, we studied the effect of heating soils and litter on the mobilization of DOM. To do this, soils and litter from two geographical areas, a conifer forest the western U.S. and a deciduous forest collected from the eastern U.S., were collected and heated to 225 and 350 °C for 2 hours. The material was then suspended in water for 24 hours prior to filtration. Leachate water quality was assessed by testing for two parameters including dissolved organic carbon (DOC) concentration and optical properties (absorbance and fluorescence). The water samples were also extracted with C18 solid-phase extraction cartridges, eluted, and analyzed using Fourier transform ion cyclotron resonance mass spectrometry, a high resolution mass spectrometry technique that can simultaneously resolve and uniquely identify tens of thousands of molecular formulas in complex mixtures like DOM. The results indicated that chemical changes to the soil and litter organic matter account for the differences in DOM mobilization from forest materials after thermal alteration.

Effect of soil in nutrient cycle assessment at dairy farms

NASA Astrophysics Data System (ADS)

van Leeuwen, Maricke; de Boer, Imke; van Dam, Jos; van Middelaar, Corina; Stoof, Cathelijne

2016-04-01

Annual farm nutrient cycle assessments give valuable insight in the nutrient cycles and nutrient losses at dairy farms. It describes nutrient use efficiencies for the entire farm and for the underlying components cattle, manure, crops and soil. In many modelling studies, soil is kept as a constant factor, while soil quality is vital for soil functioning of the ecosystem. Improving soil quality will improve the nutrient cycle, and will also have positive effect on the soil functions crop production, water cycling and greenhouse gas mitigation. Spatial variation of soil properties within a farm, however, are not included in annual nutrient cycle assessments. Therefore it is impossible to identify fields where most profit can be gained by improving farm management at field level, and it is not possible to identify and to quantify nutrient flow path ways. The aim of this study is to develop a framework to improve the annual nutrient cycle assessment at Dutch dairy farms, by including soil properties and their spatial variation within farms. Soil type and soil quality will be described by visual soil assessment of soil quality characteristics. The visual observations will be linked to the nutrient cycle assessment, using soil-hydrological model SWAP. We will demonstrate how soil quality at field level can impact on crop production, eutrophication potential and greenhouse gas potential at farm level. Also, we will show how this framework can be used by farmers to improve their farm management. This new approach is focusing on annual nutrient cycle assessment, but could also be used in life cycle assessment. It will improve understanding of soil functioning and dairy farm management.

[Soil quality assessment of forest stand in different plantation esosystems].

PubMed

Huang, Yu; Wang, Silong; Feng, Zongwei; Gao, Hong; Wang, Qingkui; Hu, Yalin; Yan, Shaokui

2004-12-01

After a clear-cutting of the first generation Cunninghamia lanceolata plantation in 1982, three plantation ecosystems, pure Michelia macclurei stand (PMS), pure Chinese-fir stand (PCS) and their mixed stand, were established in spring 1983, and their effects on soil characteristics were evaluated by measuring some soil physical, chemical, microbiological and biochemical parameters. After 20 years' plantation, all test indices showed differences among different forest management models. Both PMS and MCM had a favorable effect on soil fertility maintenance. Soil quality assessment showed that some soil functions, e.g., water availability, nutrient availability, root suitability and soil quality index were all in a moderate level under the mixed and pure PMS stands, whereas in a relatively lower level under successive PCS stand. The results also showed that there existed close correlations between soil total organic C (TOC), cation exchange capacity (CEC), microbial biomass-C (Cmic) and other soil physical, chemical and biological indices. Therefore, TOC, CEC and Cmic could be used as the indicators in assessing soil quality in this study area. In addition, there were also positive correlations between soil microbial biomass-C and TOC, soil microbial biomass-N and total N, and soil microbial biomass-P and total P in the present study.

Integrating plant litter quality, soil organic matter stabilization, and the carbon saturation concept.

PubMed

Castellano, Michael J; Mueller, Kevin E; Olk, Daniel C; Sawyer, John E; Six, Johan

2015-09-01

Labile, 'high-quality', plant litters are hypothesized to promote soil organic matter (SOM) stabilization in mineral soil fractions that are physicochemically protected from rapid mineralization. However, the effect of litter quality on SOM stabilization is inconsistent. High-quality litters, characterized by high N concentrations, low C/N ratios, and low phenol/lignin concentrations, are not consistently stabilized in SOM with greater efficiency than 'low-quality' litters characterized by low N concentrations, high C/N ratios, and high phenol/lignin concentrations. Here, we attempt to resolve these inconsistent results by developing a new conceptual model that links litter quality to the soil C saturation concept. Our model builds on the Microbial Efficiency-Matrix Stabilization framework (Cotrufo et al., 2013) by suggesting the effect of litter quality on SOM stabilization is modulated by the extent of soil C saturation such that high-quality litters are not always stabilized in SOM with greater efficiency than low-quality litters. © 2015 John Wiley & Sons Ltd.

Excessive application of pig manure increases the risk of P loss in calcic cinnamon soil in China.

PubMed

Yang, Yanju; Zhang, Haipeng; Qian, Xiaoqing; Duan, Jiannan; Wang, Gailan

2017-12-31

Soil phosphorus (P) is a critical factor affecting crop yields and water environmental quality. To investigate the degree of loss risk and forms of soil P in calcic cinnamon soil, the P fraction activities in soils were analysed using chemical methods, combined with an in situ field experiment. Seven treatments were set in this study, including control (unfertilized), no P fertilizer (No-P), mineral P fertilizer (Min-P), low (L-Man) and high (H-Man) quantities of pig manure, Min-P+L-Man, and Min-P+H-Man. The results showed that manure fertilizer could not only significantly increase maize yield but could also enhance the accumulation of soil P in organic and inorganic forms. After 23years of repeated fertilization, the soil Olsen-P contents respectively showed 64.7-, 43.7- and 31.9-fold increases in the Min-P+H-Man, Min-P+L-Man and H-Man treatments, while the soil Olsen-P in Min-P treatment only increased 23.7-fold. The soil Olsen-P thresholds ranged from 22.59 to 32.48mgkg -1 in calcic cinnamon soil to maintain a higher maize yield as well as a lower risk of P loss. Therefore, long-term excessive manure application could obviously raise the content of soil Olsen-P and increase the risk of P loss in calcic cinnamon soil. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of land use on surface-water quality in the East Everglades, Dade County, Florida

USGS Publications Warehouse

Waller, Bradley G.

1982-01-01

Water-quality characteristics were determined at five developed areas in the East Everglades, Dade County, Florida, during the 1978 wet season (June through October). These areas are designated as: Coopertown; Chekika Hammock State Park; residential area; rock-plowed tomato field; and Cracker Jack Slough agricultural area. Data from the developed areas were compared with data from four baseline sites in undeveloped areas to determine the effects of land use on the surface-water quality. The rock-plowed tomato field was the only area where surface-water quality was affected. Water quality at this field is affected by agricultural activities and chemical applications as indicated by increased concentrations of orthophosphate, organic nitrogen, organic carbon, copper, manganese, mercury, and potassium. The remaining four areas of land use had water-quality characteristics typical of baseline sites in nearby Northeast Shark River Slough or Taylor Slough. Chemical analyses of soil indicated chlorinated-hydrocarbon insecticide residues at Coopertown and the two agricultural areas, Cracker Jack Slough and the rock-plowed tomato field. Trace elements in concentrations greater than base level occurred at both agricultural areas (manganese), Chekika Hammock State Park (manganese), and at Coopertown (lead and zinc). (USGS)

Effects of of habitats and pesticides on aerobic capacity and survival of soil fauna.

PubMed

Tripathi, G; Sharma, B M

2005-06-01

Faunal health is largely dependent on their soil environment and available litter quality. So the effects of different soil habitats and pesticides on citrate synthase (CS) activity of soil fauna and its population were studied. The soil animals were collected from different pedoecosystems for habitat study. Whereas Vigna radiata based system was selected for pesticidal observations. The field was divided into five equal plots for control and treatment of gamma-BHC, quinalphos, carbaryl and cypermethrin. Soil fauna was collected by quadrat method and extracted by Tullgren funnel. Individuals of a species having similar sizes were collected for the estimation of CS activity. They were homogenized and fractions were obtained by differential centrifugation. The activity of CS was assayed spectrophotometrically. Citrate synthase (CS) activity of beetle (Rasphytus fregi), woodlouse (Porcellio laevis) and centipede (Scolopendra morsitans) varied significantly with respect to changes in different soil habitats. Though the CS activity of R. fregi, P. laevis, and S. morsitans differed among themselves but the highest activity of CS in these animals was in V. radiata and lowest in A. nilotica based pedoecosystem. The aerobic capacity of centipede was maximum followed by woodlouse and beetle. The treatment of gamma-BHC, quinalphos, carbaryl and cypermethrin significantly reduced the CS activity of these animals. Gamma-BHC showed maximum reduction in CS activity indicating highly toxic effect of organochlorine on aerobic metabolism of soil fauna. However, minimum reduction was observed in response to carbaryl (in beetle) or cypermethrin (in woodlouse/centipede) leading to impairment of aerobic capacity. The differences in pesticide effects might be assigned to the differences in chemical nature of pesticides and their interactions with below-ground fauna. Treatment of gamma-BHC and quinalphos reduced the population of Acari, Coleoptera, Collembola, other arthropods as well as total soil fauna. Acari was least affected by gamma-BHC and maximally affected (72%) in response to quinalphos. The effect of gamma-BHC was fairly similar on Coleoptera, Collembola, other arthropod and total soil fauna suggesting almost similar sensitivity to this pesticide. Likewise, quinalphos was similarly effective on Collemobola and other soil arthropods. Application of carbaryl decreased Acari and Coleoptera population but increased Collembola, other arthropods and total faunal populations. However, application of cypermethrin significantly reduced the population of Acari, Coleoptera, Collembola and total soil fauna and increased the population of other soil arthropods. In both the cases, acarine population was least affected. The observations show the habitat-specific variation in aerobic capacity of soil fauna. However, pesticide-dependent loss in population might be due to impairment of aerobic capacity of soil inhabiting animals in desert.

Winter climate change effects on soil C and N cycles in urban grasslands.

PubMed

Durán, Jorge; Rodríguez, Alexandra; Morse, Jennifer L; Groffman, Peter M

2013-09-01

Despite growing recognition of the role that cities have in global biogeochemical cycles, urban systems are among the least understood of all ecosystems. Urban grasslands are expanding rapidly along with urbanization, which is expected to increase at unprecedented rates in upcoming decades. The large and increasing area of urban grasslands and their impact on water and air quality justify the need for a better understanding of their biogeochemical cycles. There is also great uncertainty about the effect that climate change, especially changes in winter snow cover, will have on nutrient cycles in urban grasslands. We aimed to evaluate how reduced snow accumulation directly affects winter soil frost dynamics, and indirectly greenhouse gas fluxes and the processing of carbon (C) and nitrogen (N) during the subsequent growing season in northern urban grasslands. Both artificial and natural snow reduction increased winter soil frost, affecting winter microbial C and N processing, accelerating C and N cycles and increasing soil : atmosphere greenhouse gas exchange during the subsequent growing season. With lower snow accumulations that are predicted with climate change, we found decreases in N retention in these ecosystems, and increases in N2 O and CO2 flux to the atmosphere, significantly increasing the global warming potential of urban grasslands. Our results suggest that the environmental impacts of these rapidly expanding ecosystems are likely to increase as climate change brings milder winters and more extensive soil frost. © 2013 John Wiley & Sons Ltd.

Soil aggregation and glomalin in a soil quality management study in a cold, semi-arid region

USDA-ARS?s Scientific Manuscript database

Global food insecurity and rapidly diminishing water, soil, and energy resources are putting pressure on agroecosystems to efficiently produce more food while maintaining or enhancing soil quality, particularly soil aggregation. A field study established in 1993 near Mandan, ND sought to evaluate im...

Effects of Combined Application of Biogas Slurry and Chemical Fertilizer on Soil Aggregation and C/N Distribution in an Ultisol

PubMed Central

Zheng, Xuebo; Fan, Jianbo; Xu, Lei; Zhou, Jing

2017-01-01

Unreasonable use of chemical fertilizer (CF) on agricultural soil leads to massive losses of soil organic carbon (SOC) and total nitrogen (TN) in tropical and subtropical areas, where soil conditions are unfavorable for aggregate formation. This study evaluated the effects of combined application of biogas slurry (BS) plus CF on soil aggregation and aggregate—associated C/N concentration and storage in an Ultisol. Six treatments included: no fertilizer (T1), CF only (T2), partial (15% (T3), 30% (T4) and 45% (T5)) substitution of TN with BS and BS only (T6). Soil mechanical—stable aggregates (MSAs) formation and stability as well as MSAs—associated C/N concentration and storage were observed in different aggregate sizes (>5, 5–2, 2–1, 1.0–0.5, 0.50–0.25 and <0.25 mm). The proportion of MSAs >5 mm significantly increased with BS substitution (T5), while the proportions of MSAs 1.0–0.5 mm, MSAs 0.50–0.25 mm and MSAs <0.25 mm significantly decreased. Both mean weight diameter and geometric mean diameter were highest in T5, which improved soil aggregation stability as well as resulted in significantly higher SOC and TN concentrations and storage in MSAs >0.5 mm that constituted 72–82% of MSAs. Stepwise regression analysis showed that MSAs >5 mm, SOC in MSAs >5 mm and TN in MSAs >5 mm were the dominant variables affecting aggregate stability. Meanwhile SOC in MSAs <0.25 mm and TN in MSAs 2–1 mm were independent variables affecting SOC and TN concentrations in bulk soils. Therefore, certain rate of combined application of BS plus CF is an effective, eco—friendly way to improve soil quality in an Ultisol. PMID:28125647

Nitrogen additions affect litter quality and soil biochemical properties in a peatland of Northeast China

USGS Publications Warehouse

Song, Yanyu; Song, Changchun; Meng, Henan; Swarzenski, Christopher M.; Wang, Xianwei; Tan, Wenwen

2017-01-01

Nitrogen (N) is a limiting nutrient in many peatland ecosystems. Enhanced N deposition, a major component of global climate change, affects ecosystem carbon (C) balance and alters soil C storage by changing plant and soil properties. However, the effects of enhanced N deposition on peatland ecosystems are poorly understood. We conducted a two-year N additions field experiment in a peatland dominated by Eriophorum vaginatum in the Da Xing’an Mountains, Northeast China. Four levels of N treatments were applied: (1) CK (no N added), (2) N1 (6 g N m−2 yr−1), (3) N2 (12 g N m−2 yr−1), and (4) N3 (24 g N m−2  yr−1). Plant and soil material was harvested at the end of the second growing season. N additions increased litter N and phosphorus (P) content, as well as β-glucosidase, invertase, and acid-phosphatase activity, but decreased litter C:N and C:P ratios. Litter carbon content remained unchanged. N additions increased available NH4+–N and NO3−–N as well as total Gram-positive (Gram+), Gram-negative (Gram−), and total bacterial phospholipid fatty acids (PLFA) in shallow soil (0–15 cm depth). An increase in these PLFAs was accompanied by a decrease in soil labile organic C (microbial biomass carbon and dissolved organic carbon), and appeared to accelerate decomposition and reduce the stability of the soil C pool. Invertase and urease activity in shallow soils and acid-phosphatase activity in deep soils (15–30 cm depth) was inhibited by N additions. Together, these findings suggest that an increase in N deposition in peatlands could accelerate litter decomposition and the loss of labile C, as well as alter microbial biomass and function.

Seasonal induced changes in spinach rhizosphere microbial community structure with varying salinity and drought.

PubMed

Mark Ibekwe, A; Ors, Selda; Ferreira, Jorge F S; Liu, Xuan; Suarez, Donald L

2017-02-01

Salinity is a common problem under irrigated agriculture, especially in low rainfall and high evaporative demand areas of southwestern United States and other semi-arid regions around the world. However, studies on salinity effects on soil microbial communities are relatively few while the effects of irrigation-induced salinity on soil chemical and physical properties and plant growth are well documented. In this study, we examined the effects of salinity, temperature, and temporal variability on soil and rhizosphere microbial communities in sand tanks irrigated with prepared solutions designed to simulate saline wastewater. Three sets of experiments with spinach (Spinacia oleracea L., cv. Racoon) were conducted under saline water during different time periods (early winter, late spring, and early summer). Bacterial 16S V4 rDNA region was amplified utilizing fusion primers designed against the surrounding conserved regions using MiSeq® Illumina sequencing platform. Across the two sample types, bacteria were relatively dominant among three phyla-the Proteobacteria, Cyanobacteria, and Bacteroidetes-accounted for 77.1% of taxa detected in the rhizosphere, while Proteobacteria, Bacteroidetes, and Actinobacteria accounted for 55.1% of taxa detected in soil. The results were analyzed using UniFrac coupled with principal coordinate analysis (PCoA) to compare diversity, abundance, community structure, and specific bacterial groups in soil and rhizosphere samples. Permutational analysis of variance (PERMANOVA) analysis showed that soil temperature (P=0.001), rhizosphere temperature (P=0.001), rhizosphere salinity (P=0.032), and evapotranspiration (P=0.002) significantly affected beta diversity of soil and rhizosphere microbial communities. Furthermore, salinity had marginal effects (P=0.078) on soil beta diversity. However, temporal variability differentially affected rhizosphere microbial communities irrigated with saline wastewater. Therefore, microbial communities in soils impacted by saline irrigation water respond differently to irrigation water quality and season of application due to temporal effects associated with temperature. Published by Elsevier B.V.

Analysis of physical parameters related with water infiltration in tropical soils located in edges forest in urban areas

NASA Astrophysics Data System (ADS)

Márcia Longo, Regina; Cunha, Jessica C. M.; Lammoglia, Rafaella; Mendes, Deborah R.; Mungilioli, Sarah S.; Damame, Desiree B.; Demamboro, Antônio C.; Bettine, Sueli C.; Ribeiro, Admilson I.; Fengler, Felipe H.

2015-04-01

A very important factor for water infiltration into the soil in urban forest systems and suffering constant anthropogenic pressures is the analysis of soil compaction where these forests are or will be established. In this context, this work aimed to promote studies on physical parameters related to distribution of pores, compaction and soil biological activity in forest remnants border areas located in urban watersheds in Campinas / SP - Brazil. The Forest of Santa Genebra (22°49'45 "S and 47°06'33" W) has an average altitude of 680m and tropical climate of altitude, has an area of 251 ha and a nine kilometer perimeter. It constitutes 85% of Semideciduos forests and 15% swamp forest. Due to its location close to urban centers, roads and agricultural areas under direct influence of the anthropic means. For the present study analyzes were performed: particle size, soil density, porosity, matters organic, of biopores, and root distribution (primary, secondary and tertiary) and seedlings in 40 points on the perimeter of the forest equidistant 200m remaining edge. The analysis of the results allowed us to observe that areas suffer direct influence of human activities surrounding. With the results set correlations between the different parameters in order to allow a better understanding of the dynamics of water infiltration into the soil under these conditions and the quantity of tertiary roots, biopores and soil density were the best indicator of environmental quality as suffer direct influence of the surrounding areas, especially those near the most urbanized regions. In general, it can be observed that human activities such as deforestation and vehicle traffic, animals and people, promoted soil compaction and consequent changes in water infiltration into the soil in areas of edges of this remnant of these consequences affect direct numerous parameters that directly influence the dynamics of an ecosystem restoration that is now significantly affected by the occupation of their surroundings.

Introducing litter quality to the ecosystem model LPJ-GUESS: Effects on short- and long-term soil carbon dynamics

NASA Astrophysics Data System (ADS)

Portner, Hanspeter; Wolf, Annett; Rühr, Nadine; Bugmann, Harald

2010-05-01

Many biogeochemical models have been applied to study the response of the carbon cycle to changes in climate, whereby the process of carbon uptake (photosynthesis) has usually gained more attention than the equally important process of carbon release by respiration. The decomposition of soil organic matter is driven by a combination of factors like soil temperature, soil moisture and litter quality. We have introduced dependence on litter substrate quality to heterotrophic soil respiration in the ecosystem model LPJ-GUESS [Smith et al.(2001)]. We were interested in differences in model projections before and after the inclusion of the dependency both in respect to short- and long-term soil carbon dynamics. The standard implementation of heterotrophic soil respiration in LPJ-GUESS is a simple carbon three-pool model whose decay rates are dependent on soil temperature and soil moisture. We have added dependence on litter quality by coupling LPJ-GUESS to the soil carbon model Yasso07 [Tuomi et al.(2008)]. The Yasso07 model is based on an extensive number of measurements of litter decomposition of forest soils. Apart from the dependence on soil temperature and soil moisture, the Yasso07 model uses carbon soil pools representing different substrate qualities: acid hydrolyzable, water soluble, ethanol soluble, lignin compounds and humus. Additionally Yasso07 differentiates between woody and non-woody litter. In contrary to the reference implementation of LPJ-GUESS, in the new model implementation, the litter now is divided according to its specific quality and added to the corresponding soil carbon pool. The litter quality thereby differs between litter source (leaves, roots, stems) and plant functional type (broadleaved, needleleaved, grass). The two contrasting model implementations were compared and validated at one specific CarboEuropeIP site (Lägern, Switzerland) and on a broader scale all over Switzerland. Our focus lay on the soil respiration for the years 2006 and 2007 [Rühr(2009)] and present soil carbon stocks [Heim et al.(2009)]. Our Results show, that for short-term soil carbon dynamics, e.g. estimates of heterotrophic soil respiration on an annual basis, the inclusion of the dependency on litter quality is not necessary, as the differences are minor only. However, when considering long-term soil carbon dynamics, e.g. simulated estimates of present soil carbon content, the dependency on litter quality shows effect, as there are correlations with specific site factors such as site location and forest type. The inclusion of the dependence on litter quality therefore may be of importance for the projection of future soil carbon dynamics, as forest types may well be altered due to climatic change. References [Heim et al.(2009)] A. Heim, L. Wehrli, W. Eugster, and M.W.I. Schmidt. Effects of sampling design on the probability to detect soil carbon stock changes at the swiss CarboEurope site Lägeren. Geoderma, 149(3-4):347-354, 2009. [Rühr(2009)] Nadine Katrin Rühr. Soil respiration in a mixed mountain forest : environmental drivers and partitioning of component fluxes. PhD thesis, ETH, 2009. [Smith et al.(2001)] Benjamin Smith, I. Colin Prentice, and Martin T. Sykes. Representation of vegetation dynamics in the modelling of terrestrial ecosystems: comparing two contrasting approaches within european climate space. Global Ecology and Biogeography, 10(6):621-637, 2001. [Tuomi et al.(2008)] Mikko Tuomi, Pekka Vanhala, Kristiina Karhu, Hannu Fritze, and Jari Liski. Heterotrophic soil respiration-Comparison of different models describing its temperature dependence. Ecological Modelling, 211(1-2): 182-190, 2008.

Use of Energy Crop (Ricinus communis L.) for Phytoextraction of Heavy Metals Assisted with Citric Acid.

PubMed

Zhang, Hui; Chen, Xueping; He, Chiquan; Liang, Xia; Oh, Kokyo; Liu, Xiaoyan; Lei, Yanru

2015-01-01

Ricinus communis L. is a bioenergetic crop with high-biomass production and tolerance to cadmium (Cd) and lead (Pb), thus, the plant is a candidate crop for phytoremediation. Pot experiments were performed to study the effects of citric acid in enhancing phytoextraction of Cd/Pb by Ricinus communis L. Citric acid increased Cd and Pb contents in plant shoots in all treatments by about 78% and 18-45%, respectively, at the dosage of 10 mM kg(-1) soil without affecting aboveground biomass production. Addition of citric acid reduced CEC, weakened soil adsorption of heavy metals and activated Cd and Pb in soil solutions. The acid-exchangeable fraction (BCR-1) of Pb remained lower than 7% and significantly increased with citric acid amendment. Respective increases in soil evaluation index induces by 14% and 19% under the Cd1Pb50 and Cd1Pb250 treatments upon addition of citric acid resulted in soil quality improvement. Ricinus communis L. has great potential in citric acid-assisted phytoextraction for Cd and Pb remediation.

Simulating soil phosphorus dynamics for a phosphorus loss quantification tool.

PubMed

Vadas, Peter A; Joern, Brad C; Moore, Philip A

2012-01-01

Pollution of fresh waters by agricultural phosphorus (P) is a water quality concern. Because soils can contribute significantly to P loss in runoff, it is important to assess how management affects soil P status over time, which is often done with models. Our objective was to describe and validate soil P dynamics in the Annual P Loss Estimator (APLE) model. APLE is a user-friendly spreadsheet model that simulates P loss in runoff and soil P dynamics over 10 yr for a given set of runoff, erosion, and management conditions. For soil P dynamics, APLE simulates two layers in the topsoil, each with three inorganic P pools and one organic P pool. It simulates P additions to soil from manure and fertilizer, distribution among pools, mixing between layers due to tillage and bioturbation, leaching between and out of layers, crop P removal, and loss by surface runoff and erosion. We used soil P data from 25 published studies to validate APLE's soil P processes. Our results show that APLE reliably simulated soil P dynamics for a wide range of soil properties, soil depths, P application sources and rates, durations, soil P contents, and management practices. We validated APLE specifically for situations where soil P was increasing from excessive P inputs, where soil P was decreasing due to greater outputs than inputs, and where soil P stratification occurred in no-till and pasture soils. Successful simulations demonstrate APLE's potential to be applied to major management scenarios related to soil P loss in runoff and erosion. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Polymer tensiometers in a saline environment.

NASA Astrophysics Data System (ADS)

van der Ploeg, Martine; Gooren, H. P. A.; Bakker, G.; Russell, W.; Hoogendam, C. W.; Huiskes, C.; Shouse, P.; de Rooij, G. H.

2010-05-01

It is estimated that 20% of all cultivated land and nearly half of the irrigated land is salt-affected, which pose major economic and environmental problems. Salinity may be the result of two processes; dryland and irrigation salinity. Dryland salinity is caused by a rise in the groundwater table, which occurs as a result of the replacement of deep-rooted, perennial native vegetation by shallow-rooted annual species meant for production. Irrigation salinity may occur as a result of poor water quality, poor drainage, or inefficient use of water. Consequently, new strategies to enhance crop yield stability on saline soils represent a major research priority (Botella et al. 2005). At the same time, native vegetation is capable of thriving under saline and/or dry conditions. The plant physiology of such vegetation has been investigated thoroughly, but the relation with in situ soil properties (soil moisture and salinity) may be more difficult to unravel as soil moisture sensors are less sensitive in dry soil, and the signal of most soil moisture content sensors is strongly attenuated by soil salinity. Recently, polymer tensiometer were developed that are able to measure matric potentials (closely related to a soil's moisture status) in dry soils. Polymer tensiometers consist of a solid ceramic, a stainless steel cup and a pressure transducer. The ceramic consist of a support layer and a membrane with 2 nm pore-size to prevent polymer leakage. Between the ceramic membrane and the pressure transducer a tiny chamber is located, which contains the polymer solution. The polymer's osmotic potential strongly reduces the total water potential inside the polymer tensiometer, which causes build-up of osmotic pressure. Polymer tensiometers would thus be an ideal instrument to measure in dry soil, if the polymer inside the tensiometer is not affected by the salts in the soil solution. We will address some key issues regarding the use of POTs in saline environments by showing results from a field experiment conducted in a very saline soil. This research was funded by the Dutch Technology Foundation (STW).

Short-term effects of different organic amendments on soil chemical, biochemical and biological indicators

NASA Astrophysics Data System (ADS)

Mondelli, Donato; Aly, Adel; Yirga Dagnachew, Ababu; Piscitelli, Lea; Dumontet, Stefano; Miano, Teodoro

2014-05-01

The limited availability of animal manure and the high cost of good quality compost lead to difficult soil quality management under organic agriculture. Therefore, it is important to find out alternative organic soil amendments and more flexible strategies that are able to sustain crop productivity and maintain and enhance soil quality. A three years study was carried out in the experimental fields of the Mediterranean Agronomic Institute of Bari located in Valenzano, Italy. The main objective of this research is to investigate the effects of different fertility management strategies on soil quality in order to estimate the role of innovative matrices for their use in organic farming. The experiment consists of seven treatments applied to a common crop rotation. The treatments include alternative organic amendments (1- olive mill wastewater OMW, 2- residues of mushroom cultivation MUS, 3- coffee chaff COF), common soil amendments (4- compost COM, 5- faba bean intercropping LEG, 6- cow manure - MAN) and as a reference treatment (7- mineral fertilizer COV). The soil quality was assessed before and after the application of the treatments, through biological (microbial biomass carbon and nitrogen, soil respiration and metabolic quotient), biochemical (soil enzymatic activities: β-glucosidase, alkaline phospatase, urease, fluorescein diacetate (FDA) hydrolysis), and chemical (pH, soil organic carbon, soil organic matter, total nitrogen, available phosphorous, exchangeable potassium, dissolved organic carbon and total dissolved nitrogen) indicators. Based on the results obtained after the second year, all treatments were able to improve various soil chemical parameters as compared to mineral fertilizer. The incorporation of COF and OMW seemed to be more effective in improving soil total N and exchangeable K, while MAN significantly increased available P. All the amendments enhance dissolved organic C, soil respiration, microbial biomass and metabolic quotient as compared to control soil. Results concerning biochemical indicators revealed that phosphatase and β-glycosidase were significantly reduced, while activities of urease and FDA were improved in all amended plots in comparison to the control, regardless of amendment type. Data demonstrated the efficiency, the high sensitivity and a quick response of the biochemical indicators in assessing soil quality changes. As a conclusion, it is possible to emphasize that alternative and common soil organic amendments behave similarly in enhancing the chemical, biochemical and biological properties. The alternative soil organic amendments could, then, be candidates for substituting some commonly used one which are currently showing shortage in their supply and a lowering in their quality. Keywords: Organic agriculture, Soil quality, Enzymatic activities, Olive mill wastewater, Residues of mushroom cultivation, Coffee chaff.

Fire Effects on Soil and Dissolved Organic Matter in a Southern Appalachian Hardwood Forest: Movement of Fire-Altered Organic Matter Across the Terrestrial-Aquatic Interface Following the Great Smoky Mountains National Park Fire of 2016

NASA Astrophysics Data System (ADS)

Matosziuk, L.; Gallo, A.; Hatten, J. A.; Heckman, K. A.; Nave, L. E.; Sanclements, M.; Strahm, B. D.; Weiglein, T.

2017-12-01

Wildfire can dramatically affect the quantity and quality of soil organic matter (SOM), producing thermally altered organic material such as pyrogenic carbon (PyC) and polyaromatic hydrocarbons (PAHs). The movement of this thermally altered material through terrestrial and aquatic ecosystems can differ from that of unburned SOM, with far-reaching consequences for soil carbon cycling and water quality. Unfortunately, due to the rapid ecological changes following fire and the lack of robust pre-fire controls, the cycling of fire-altered carbon is still poorly understood. In December 2016, the Chimney Tops 2 fire in Great Smoky Mountains National Park burned over co-located terrestrial and aquatic NEON sites. We have leveraged the wealth of pre-fire data at these sites (chemical, physical, and microbial characterization of soils, continuous measurements of both soil and stream samples, and five soil cores up to 110 cm in depth) to conduct a thorough study of the movement of fire-altered organic matter through terrestrial and aquatic ecosystems. Stream samples have been collected weekly beginning 5 weeks post-fire. Grab samples of soil were taken at discrete time points in the first two months after the fire. Eight weeks post-fire, a second set of cores was taken and resin lysimeters installed at three different depths. A third set of cores and grab samples will be taken 8-12 months after the fire. In addition to routine soil characterization techniques, solid samples from cores and grab samples at all time points will be analyzed for PyC and PAHs. To determine the effect of fire on dissolved organic matter (DOM), hot water extracts of these soil samples, as well as the stream samples and lysimeter samples, will also be analyzed for PyC and PAHs. Selected samples will be analyzed by 1D- and 2D-NMR to further characterize the chemical composition of DOM. This extensive investigation of the quantity and quality of fire-altered organic material at discrete time points will provide insight into the production and cycling of thermally-altered SOM and DOM. We hypothesize that PyC will be an important source of SOM to surface mineral soil horizons, and that the quantity of DOM will increase after fire, providing a rapid pulse of C to deep soils and aquatic systems.

Soil degradation in farmlands of California's San Joaquin Valley resulting from drought-induced land-use changes

NASA Astrophysics Data System (ADS)

Scudiero, Elia; Skaggs, Todd; Anderson, Ray; Corwin, Dennis

2016-04-01

Irrigation in California's Central Valley (USA) has decreased significantly due to water shortages resulting from the current drought, which began in 2010. In particular, fallow fields in the west side of the San Joaquin Valley (WSJV), which is the southwest portion of the Central Valley, increased from around 12% in the years before the drought (2007-2010) to 20-25% in the following years (2011-2015). We monitored and mapped drought-induced edaphic changes in salinity at two scales: (i) field scale (32.4-ha field in Kings County) and (ii) water district scale (2400 ha at -former- Broadview Water District in Fresno County). At both scales drought-induced land-use changes (i.e., shift from irrigated agriculture to fallow) drastically decreased soil quality by increasing salinity (and sodicity), especially in the root-zone (top 1.2 m). The field study monitors the spatial (three dimensions) changes of soil salinity (and sodicity) in the root-zone during 10 years of irrigation with drainage water followed by 4 years of no applied irrigation water (only rainfall) due to drought conditions. Changes of salinity (and other edaphic properties), through the soil profile (down to 1.2 m, at 0.3-m increments), were monitored and modeled using geospatial apparent electrical conductivity measurements and extensive soil sampling in 1999, 2002, 2004, 2009, 2011, and 2013. Results indicate that when irrigation was applied, salts were leached from the root-zone causing a remarkable improvement in soil quality. However, in less than two years after termination of irrigation, salinity in the soil profile returned to original levels or higher across the field. At larger spatial scales the effect of drought-induced land-use change on root-zone salinity is also evident. Up to spring 2006, lands in Broadview Water District (BWD) were used for irrigated agriculture. Water rights were then sold and the farmland was retired. Soil quality decreased since land retirement, especially during the drought years. Root-zone soil salinity was mapped in 1991 using geospatial apparent electrical conductivity measurements and extensive soil sampling and in 2013 using recent root-zone remote sensing salinity map for the WSJV (developed and published by the U.S. Salinity Laboratory, USDA-ARS), which was calibrated and (independently) validated, including fields from the BWD. Results reveal dramatic increases in soil salinity for all the fields that were originally non-saline and slightly-saline in 1991. Additionally, time-series analysis of very-high resolution ortho-imagery (from Google Earth and USGS) suggests that surface soil quality drastically decreased especially during the drought years. Our research shows how terminating irrigation in California's Central Valley can lead to substantial soil salinization in a very short time. Salinization in WSJV due to the termination of irrigation is a consequence of the complex multi-scale interaction of geomorphologic, topographic, and anthropogenic factors requiring yearly monitoring to adequately assess the impacts of drought for use in field- and basin-scale water management decisions. Among other concerns, increased salinity and sodicity affect vegetation growth and may lead to increased soil erosion and very-fine dust formation creating health and environmental hazards.

Pollution Status of Pakistan: A Retrospective Review on Heavy Metal Contamination of Water, Soil, and Vegetables

PubMed Central

Arshad, Jahanzaib; Iqbal, Farhat; Sajjad, Ashif; Mehmood, Zahid

2014-01-01

Trace heavy metals, such as arsenic, cadmium, lead, chromium, nickel, and mercury, are important environmental pollutants, particularly in areas with high anthropogenic pressure. In addition to these metals, copper, manganese, iron, and zinc are also important trace micronutrients. The presence of trace heavy metals in the atmosphere, soil, and water can cause serious problems to all organisms, and the ubiquitous bioavailability of these heavy metal can result in bioaccumulation in the food chain which especially can be highly dangerous to human health. This study reviews the heavy metal contamination in several areas of Pakistan over the past few years, particularly to assess the heavy metal contamination in water (ground water, surface water, and waste water), soil, sediments, particulate matter, and vegetables. The listed contaminations affect the drinking water quality, ecological environment, and food chain. Moreover, the toxicity induced by contaminated water, soil, and vegetables poses serious threat to human health. PMID:25276818