The effects of multi-walled carbon nanotubes on soil microbial community functional and structural diversity

USDA-ARS?s Scientific Manuscript database

Applications of nanomaterials, including carbon nanotubes (CNTs), are increasing; however, their impact on the environment is still not well understood. A semi-arid soil was treated with multi-walled carbon nanotubes (MWCNTs) at four different concentrations (10-10000 mgMWCNTs kg-1soil), and incubat...

Kinetics of biotransformation of chlorpyrifos in aqueous and soil slurry environments.

PubMed

Tiwari, Manoj K; Guha, Saumyen

2014-03-15

The attenuation of chlorpyrifos (CPF) by the enriched indigenous soil microorganism was studied in 15 d aerobic and 60 d anaerobic batch experiments in aqueous and soil slurry (1:3 w/w) media. At the end of the batch experiments, 2.78 ± 0.11 μM of CPF was degraded by 82% in aerobic and 66% in anaerobic aqueous environments, while 12.4 ± 0.5 μM of CPF was degraded by 48% in aerobic and 31% in anaerobic soil slurries. The reduced degradation in the soil slurries was due to the significantly (2-10 times) slower rate of degradation of soil phase CPF compared with its degradation rate in water. The pathways of degradation of CPF were identified, including a partial anaerobic degradation pathway that is constructed for the first time. The simulation of the various conversions in the degradation pathways using first order kinetics was used to analyze relative persistence of metabolites. The common metabolite 3,5,6-trichloro-2-pyridinol (TCP) accumulated (increased monotonically during the period of experiments) in aerobic soil slurry and in anaerobic aqueous as well as soil slurry systems but did not accumulate in aerobic aqueous system. The most toxic compound in the pathway, chlorpyrifos oxon (CPFO) was not detected in anaerobic environment. In aerobic environment, CPFO was short lived in aqueous medium, but accumulated slowly in the soils. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effect of Metal Oxide Nanoparticles on Microbial Community Structure and Function in Two Different Soil Types

PubMed Central

Frenk, Sammy; Ben-Moshe, Tal; Dror, Ishai; Berkowitz, Brian; Minz, Dror

2013-01-01

Increased availability of nanoparticle-based products will, inevitably, expose the environment to these materials. Engineered nanoparticles (ENPs) may thus find their way into the soil environment via wastewater, dumpsters and other anthropogenic sources; metallic oxide nanoparticles comprise one group of ENPs that could potentially be hazardous for the environment. Because the soil bacterial community is a major service provider for the ecosystem and humankind, it is critical to study the effects of ENP exposure on soil bacteria. These effects were evaluated by measuring bacterial community activity, composition and size following exposure to copper oxide (CuO) and magnetite (Fe3O4) nanosized (<50 nm) particles. Two different soil types were examined: a sandy loam (Bet-Dagan) and a sandy clay loam (Yatir), under two ENP concentrations (1%, 0.1%). Results indicate that the bacterial community in Bet-Dagan soil was more susceptible to change due to exposure to these ENPs, relative to Yatir soil. More specifically, CuO had a strong effect on bacterial hydrolytic activity, oxidative potential, community composition and size in Bet-Dagan soil. Few effects were noted in the Yatir soil, although 1% CuO exposure did cause a significant decreased oxidative potential and changes to community composition. Fe3O4 changed the hydrolytic activity and bacterial community composition in Bet-Dagan soil but did not affect the Yatir soil bacterial community. Furthermore, in Bet-Dagan soil, abundance of bacteria annotated to OTUs from the Bacilli class decreased after addition of 0.1% CuO but increased with 1% CuO, while in Yatir soil their abundance was reduced with 1% CuO. Other important soil bacterial groups, including Rhizobiales and Sphingobacteriaceae, were negatively affected by CuO addition to soil. These results indicate that both ENPs are potentially harmful to soil environments. Furthermore, it is suggested that the clay fraction and organic matter in different soils interact with the ENPs and reduce their toxicity. PMID:24349575

Listeria monocytogenes, a down-to-earth pathogen

PubMed Central

Vivant, Anne-Laure; Garmyn, Dominique; Piveteau, Pascal

2013-01-01

Listeria monocytogenes is the causative agent of the food-borne life threatening disease listeriosis. This pathogenic bacterium received much attention in the endeavor of deciphering the cellular mechanisms that underlie the onset of infection and its ability to adapt to the food processing environment. Although information is available on the presence of L. monocytogenes in many environmental niches including soil, water, plants, foodstuff and animals, understanding the ecology of L. monocytogenes in outdoor environments has received less attention. Soil is an environmental niche of pivotal importance in the transmission of this bacterium to plants and animals. Soil composition, microbial communities and macrofauna are extrinsic edaphic factors that direct the fate of L. monocytogenes in the soil environment. Moreover, farming practices may further affect its incidence. The genome of L. monocytogenes presents an extensive repertoire of genes encoding transport proteins and regulators, a characteristic of the genome of ubiquitous bacteria. Postgenomic analyses bring new insights in the process of soil adaptation. In the present paper focussing on soil, we review these extrinsic and intrinsic factors that drive environmental adaptation of L. monocytogenes. PMID:24350062

Listeria monocytogenes, a down-to-earth pathogen.

PubMed

Vivant, Anne-Laure; Garmyn, Dominique; Piveteau, Pascal

2013-01-01

Listeria monocytogenes is the causative agent of the food-borne life threatening disease listeriosis. This pathogenic bacterium received much attention in the endeavor of deciphering the cellular mechanisms that underlie the onset of infection and its ability to adapt to the food processing environment. Although information is available on the presence of L. monocytogenes in many environmental niches including soil, water, plants, foodstuff and animals, understanding the ecology of L. monocytogenes in outdoor environments has received less attention. Soil is an environmental niche of pivotal importance in the transmission of this bacterium to plants and animals. Soil composition, microbial communities and macrofauna are extrinsic edaphic factors that direct the fate of L. monocytogenes in the soil environment. Moreover, farming practices may further affect its incidence. The genome of L. monocytogenes presents an extensive repertoire of genes encoding transport proteins and regulators, a characteristic of the genome of ubiquitous bacteria. Postgenomic analyses bring new insights in the process of soil adaptation. In the present paper focussing on soil, we review these extrinsic and intrinsic factors that drive environmental adaptation of L. monocytogenes.

[Study on a new prevention and control model on soil-borne parasitic diseases in rural areas of China].

PubMed

Li, Xue-Ming; Chen, Ying-Dan; Xu, Long-Qi; Zhou, Chang-Hai; Ou-Yang, Yi; Lin, Rui; Yang, Fang-Fang; Zhang, Xiao-Juan; Wang, Ge; Liu, Teng; Wang, Jing

2011-12-01

To explore a new prevention and control model on soil-borne parasitic diseases in rural areas of China. Eight provinces and autonomous regions were selected in China as demonstration areas implementing integrated control on soil-borne parasitic diseases. The integrated control measures included authority organization and harmonization, health education, deworming, and environment modification. After three years, the infection rates of soil-borne parasitic diseases were significantly decreased in these areas. There were three safe guard and organization modes, three health education modes, four mass worming medication modes, and two modes of water, toilet and environment changes. The work in the various demonstration areas was summarized which pointed out a new model with efficiency and local characteristics on soil-borne parasitic disease prevention and control.

Analysis of genotype by environment interaction in Louisiana sugarcane research plots by GGE biplots

USDA-ARS?s Scientific Manuscript database

Genotype by environment (G x E) interactions complicate genotype selection in breeding programs. In south Louisiana, sugarcane is cultivated under a wide range of environments including soil types and cultural management practices. To evaluate experimental genotypes in different environments, the va...

Aluminium Toxicity to Plants as Influenced by the Properties of the Root Growth Environment Affected by Other Co-Stressors: A Review.

PubMed

Siecińska, Joanna; Nosalewicz, Artur

Aluminium toxicity to crops depends on the acidity of the soil and specific plant resistance. However, it is also strongly affected by other environmental factors that have to be considered to properly evaluate the resultant effects on plants. Observed weather perturbations and predicted climate changes will increase the probability of co-occurrence of aluminium toxicity and other abiotic stresses.In this review the mechanisms of plant-aluminium interactions are shown to be influenced by soil mineral nutrients, heavy metals, organic matter, oxidative stress and drought. Described effects of aluminium toxicity include: root growth inhibition, reduction in the uptake of mineral nutrients resulting from the inhibition of transport processes through ion channels; epigenetic changes to DNA resulting in gene silencing. Complex processes occurring in the rhizosphere are highlighted, including the role of soil organic matter and aluminium detoxification by mucilage.There is a considerable research gap in the understanding of root growth in the soil environment in the presence of toxic aluminium concentrations as affected by interactions with abiotic stressors. This knowledge is important for the selection of feasible methods aimed at the reduction of negative consequences of crop production in acidic soils affected by adverse growth environment.

Phosphatase activity in Antarctica soil samples as a biosignature of extant life

NASA Astrophysics Data System (ADS)

Sato, Shuji; Itoh, Yuki; Takano, Yoshinori; Fukui, Manabu; Kaneko, Takeo; Kobayashi, Kensei

Microbial activities have been detected in such extreme terrestrial environments as deep lithosphere, a submarine hydrothermal systems, stratosphere, and Antarctica. Microorganisms have adapted to such harsh environments by evolving their biomolecules. Some of these biomolecules such as enzymes might have different characteristics from those of organisms in ordinary environments. Many biosignatures (or biomarkers) have been proposed to detect microbial activities in such extreme environments. A number of techniques are proposed to evaluate biological activities in extreme environments including cultivation methods, assay of metabolism, and analysis of bioorganic compounds like amino acids and DNA. Enzyme activities are useful signature of extant life in extreme environments. Among many enzymes, phosphatase could be a good indicator of biological activities, since phosphate esters are essential for all the living terrestrial organisms. In addition, alkaline phosphatase is known as a typical zinc-containing metalloenzyme and quite stable in environments. We analyzed phosphatase activities in Antarctica soil samples to see whether they can be used as biosignatures for extant life. In addition, we characterized phosphatases extracted from the Antarctica soil samples, and compared with those obtained from other types of environments. Antarctica surface environments are quite severe environments for life since it is extremely cold and dry and exposed to strong UV and cosmic rays. We tried to evaluate biological activities in Antarctica by measuring phosphatase activities. Surface soil samples are obtained at the Sites 1-8 near Showa Base in Antarctica during the 47th Japan Antarctic exploration mission in 2005-6. Activities of acid phosphatase (ACP) and alkaline phosphatase (ALP) are measured spectrophotometrically after mixing the powdered sample and p-nitrophenyl phosphate solution (pH 6.5 for ACP, pH 8.0 for ALP). ALP was characterized after extraction from soils with Tris-HCl buffer (pH 9.0), where the activity was measured fluorometrically with 4-methylumbelliferyl phosphate (pH 8.0) as a substance. The soil of Site 8 (near a penguin rookery) showed almost the same level of ACP and ALP activities as usual surface soil sampled in YNU campus, while the soil of Sites 1-7 showed much less activities. ALP in the extract from the soil of Site 8 was characterized. It showed the maximal at 338 K, while ALP from the campus soil showed the maximal at 358 K. Gel filtration chromatography showed that the ALP activity was found only in the fraction whose molecular weights were over 60000. The ALP activity was diminished with EDTA and was recovered with addition of zinc ion. The present results showed that zinc-containing metalloenzymes, which had lower optimum temperature than those in usual environments, are present in Antarctica soil. It was suggested that phosphatases are good bio-signatures for extant life in extreme environments.

Some aspects of remediation of contaminated soils

NASA Astrophysics Data System (ADS)

Bech, Jaume; Korobova, Elena; Abreu, Manuela; Bini, Claudio; Chon, Hyo-Taek; Pérez-Sirvent, Carmen; Roca, Núria

2014-05-01

Soils are essential components of the environment, a limited precious and fragile resource, the quality of which should be preserved. The concentration, chemical form and distribution of potential harmful elements in soils depends on parent rocks, weathering, soil type and soil use. However, their concentration can be altered by mismanagement of industrial and mining activities, energy generation, traffic increase, overuse of agrochemicals, sewage sludge and waste disposal, causing contamination, environmental problems and health concerns. Heavy metals, some metalloids and radionuclides are persistent in the environment. This persistence hampers the cost/efficiency of remediation technologies. The choice of the most appropriate soil remediation techniques depends of many factors and essentially of the specific site. This contribution aims to offer an overview of the main remediation methods in contaminated soils. There are two main groups of technologies: the first group dealing with containment and confinement, minimizing their toxicity, mobility and bioavailability. Containment measures include covering, sealing, encapsulation and immobilization and stabilization. The second group, remediation with decontamination, is based on the remotion, clean up and/or destruction of contaminants. This group includes mechanical procedures, physical separations, chemical technologies such as soil washing with leaching or precipitation of harmful elements, soil flushing, thermal treatments and electrokinetic technologies. There are also two approaches of biological nature: bioremediation and phytoremediation. Case studies from Chile, Ecuador, Italy, Korea, Peru, Portugal, Russia and Spain, will be discussed in accordance with the time available.

Site productivity and diversity of the Middle Mountain long-term soil productivity study, West Virginia: Pre-experimental site characterization

Treesearch

Mary Beth Adams

2018-01-01

To better understand the impacts of a changing environment and interactions with forest management options for forest resources, including soil, large long-term experiments are required. Such experiments require careful documentation of reference or pre-experimental conditions. This publication describes the Middle Mountain Long-term Soil Productivity (LTSP) Study,...

77 FR 74222 - Notice of Lodging of Consent Decree Under the Comprehensive Environmental Response, Compensation...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-13

... protection of public health and the environment. The cleanup goal for surface soil is PCBs of 25 ppm which is... and Highway 202. The selected remedy for OU-3 is soil capping and expanded groundwater extraction. The objectives of the remedial action for soils include: Reducing risks to area workers and trespassers from...

Hydrologic behavior of model slopes with synthetic water repellent soils

NASA Astrophysics Data System (ADS)

Zheng, Shuang; Lourenço, Sérgio D. N.; Cleall, Peter J.; Chui, Ting Fong May; Ng, Angel K. Y.; Millis, Stuart W.

2017-11-01

In the natural environment, soil water repellency decreases infiltration, increases runoff, and increases erosion in slopes. In the built environment, soil water repellency offers the opportunity to develop granular materials with controllable wettability for slope stabilization. In this paper, the influence of soil water repellency on the hydrological response of slopes is investigated. Twenty-four flume tests were carried out in model slopes under artificial rainfall; soils with various wettability levels were tested, including wettable (Contact Angle, CA < 90°), subcritical water repellent (CA ∼ 90°) and water repellent (CA > 90°). Various rainfall intensities (30 mm/h and 70 mm/h), slope angles (20° and 40°) and relative compactions (70% and 90%) were applied to model the response of natural and man-made slopes to rainfall. To quantitatively assess the hydrological response, a number of measurements were made: runoff rate, effective rainfall rate, time to ponding, time to steady state, runoff acceleration, total water storage and wetting front rate. Overall, an increase in soil water repellency reduces infiltration and shortens the time for runoff generation, with the effects amplified for high rainfall intensity. Comparatively, the slope angle and relative compaction had only a minor contribution to the slope hydrology. The subcritical water repellent soils sustained infiltration for longer than both the wettable and water repellent soils, which presents an added advantage if they are to be used in the built environment as barriers. This study revealed substantial impacts of man-made or synthetically induced soil water repellency on the hydrological behavior of model slopes in controlled conditions. The results shed light on our understanding of hydrological processes in environments where the occurrence of natural soil water repellency is likely, such as slopes subjected to wildfires and in agricultural and forested slopes.

Factors influencing the rates, processes and magnitude of accumulation of carbon in desert soils

NASA Technical Reports Server (NTRS)

Mcfadden, Leslie D.

1994-01-01

This report summarizes research funded through NASA's Soil Landscape Climate Program which includes studies of the systematics of carbon storage and flux in the terrestrial environment, specifically terrestrial soils. Efforts focussed on the nature of carbon behavior in arid environments, where the majority of the carbon is present as inorganic carbon stored as pedogenic carbonate in desert calcic soils. Studies were supported of soils in two areas of western North America's major deserts: the Mojave Desert and the Chihuahuan Desert. Part 1 of this report summarizes the results of research conducted in the area of the Providence Mountains, California in the eastern Mojave Desert. Part 2 of this report summarizes the results of research in the Sevilleta Wildlife Refuge in central New Mexico, one of the sites of the UMN Biology Department's Long Term Ecological Research.

Transfer of fallout radionuclides derived from Fukushima NPP accident: 1 year study on transfer of radionuclides through geomorphic processes

NASA Astrophysics Data System (ADS)

Onda, Y.; Kato, H.; Fukushima, T.; Wakahara, T.; Kita, K.; Takahashi, Y.; Sakaguchi, A.; Tanaka, K.; Yamashiki, Y.; Yoshida, N.

2012-12-01

After the Fukushima Daiichi Nuclear Power Plant acciden, fallout radionuclides on the ground surface will transfer through geomorphic processes. Therefore, in order to estimate future changes in radionuclide deposition, migration process of radionuclides in forests, soils, ground water, rivers, and entrainment from trees and soils should be confirmed. We (FMWSE group) was funded by MEXT, Japanese government, and 1 year following monitoring has been conducted about 1 year. 1 Migration study of radionuclides in natural environment including forests and rivers 1) Study on depth distribution of radiocaesium in soils within forests, fields, and grassland. 2) Confirmation of radionuclide distribution and investigation on migration in forests. 3) Study on radionuclide migration due to soil erosion under different land use. 4) Measurement of radionuclides entrained from natural environment including forests and soils. 2 Migration study of radionuclides through hydrological cycle such as soil water, rivers, lakes and ponds, ground water. 1) Investigation on radionuclide migration through soil water, ground water, stream water, spring water under different land use. 2) Study on paddy-to-river transfer of radionuclides through suspended sediment. 3) Study on river-to-ocean transfer of radionuclides via suspended sediment. 4) Confirmation of radionuclide deposition in ponds and reservoirs. We will present how and where the fallout radionulides transfter through geomorphic processes.

Soil Oxidation-Reduction in Wetlands and Its Impact on Plant Functioning

PubMed Central

Pezeshki, S. R.; DeLaune, R. D.

2012-01-01

Soil flooding in wetlands is accompanied by changes in soil physical and chemical characteristics. These changes include the lowering of soil redox potential (Eh) leading to increasing demand for oxygen within the soil profile as well as production of soil phytotoxins that are by-products of soil reduction and thus, imposing potentially severe stress on plant roots. Various methods are utilized for quantifying plant responses to reducing soil conditions that include measurement of radial oxygen transport, plant enzymatic responses, and assessment of anatomical/morphological changes. However, the chemical properties and reducing nature of soil environment in which plant roots are grown, including oxygen demand, and other associated processes that occur in wetland soils, pose a challenge to evaluation and comparison of plant responses that are reported in the literature. This review emphasizes soil-plant interactions in wetlands, drawing attention to the importance of quantifying the intensity and capacity of soil reduction for proper evaluation of wetland plant responses, particularly at the process and whole-plant levels. Furthermore, while root oxygen-deficiency may partially account for plant stress responses, the importance of soil phytotoxins, produced as by-products of low soil Eh conditions, is discussed and the need for development of methods to allow differentiation of plant responses to reduced or anaerobic soil conditions vs. soil phytotoxins is emphasized. PMID:24832223

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.

Accelerated biodegradation of a herbicide applied to the roadside environment using adapted soil microorganisms : final report.

DOT National Transportation Integrated Search

1994-06-01

The extent and duration of pollution from herbicide spills and deliberate applications is related to properties of the herbicide and soil. Objectives of this study included the development of experimental procedures and mathematical models to determi...

Meteorological measurements. Chapter 3

Treesearch

David Y. Hollinger

2008-01-01

Environmental measurements are useful for detecting climatic trends, understanding how the environment influences biological processes, and as input to ecosystem models. Landscape-scale monitoring requires a suite of environmental measures for all of these purposes, including air and soil temperature, humidity, wind speed, precipitation and soil moisture, and different...

Complete Genome Sequence of the Diesel-Degrading Acinetobacter sp. Strain DR1 ▿

PubMed Central

Jung, Jaejoon; Baek, Jeong-Hun; Park, Woojun

2010-01-01

The genus Acinetobacter is ubiquitous in soil, aquatic, and sediment environments and includes pathogenic strains, such as A. baumannii. Many Acinetobacter species isolated from various environments have biotechnological potential since they are capable of degrading a variety of pollutants. Acinetobacter sp. strain DR1 has been identified as a diesel degrader. Here we report the complete genome sequence of Acinetobacter sp. DR1 isolated from the soil of a rice paddy. PMID:20639327

Benchmark Data Set for Wheat Growth Models: Field Experiments and AgMIP Multi-Model Simulations.

NASA Technical Reports Server (NTRS)

Asseng, S.; Ewert, F.; Martre, P.; Rosenzweig, C.; Jones, J. W.; Hatfield, J. L.; Ruane, A. C.; Boote, K. J.; Thorburn, P.J.; Rotter, R. P.

2015-01-01

The data set includes a current representative management treatment from detailed, quality-tested sentinel field experiments with wheat from four contrasting environments including Australia, The Netherlands, India and Argentina. Measurements include local daily climate data (solar radiation, maximum and minimum temperature, precipitation, surface wind, dew point temperature, relative humidity, and vapor pressure), soil characteristics, frequent growth, nitrogen in crop and soil, crop and soil water and yield components. Simulations include results from 27 wheat models and a sensitivity analysis with 26 models and 30 years (1981-2010) for each location, for elevated atmospheric CO2 and temperature changes, a heat stress sensitivity analysis at anthesis, and a sensitivity analysis with soil and crop management variations and a Global Climate Model end-century scenario.

Discharge of swine wastes risks water quality and food safety: Antibiotics and antibiotic resistance genes from swine sources to the receiving environments.

PubMed

He, Liang-Ying; Ying, Guang-Guo; Liu, You-Sheng; Su, Hao-Chang; Chen, Jun; Liu, Shuang-Shuang; Zhao, Jian-Liang

2016-01-01

Swine feedlots are widely considered as a potential hotspot for promoting the dissemination of antibiotic resistance genes (ARGs) in the environment. ARGs could enter the environment via discharge of animal wastes, thus resulting in contamination of soil, water, and food. We investigated the dissemination and diversification of 22 ARGs conferring resistance to sulfonamides, tetracyclines, chloramphenicols, and macrolides as well as the occurrence of 18 corresponding antibiotics from three swine feedlots to the receiving water, soil environments and vegetables. Most ARGs and antibiotics survived the on-farm waste treatment processes in the three swine farms. Elevated diversity of ARGs was observed in the receiving environments including river water and vegetable field soils when compared with respective controls. The variation of ARGs along the vertical soil profiles of vegetable fields indicated enrichment and migration of ARGs. Detection of various ARGs and antibiotic residues in vegetables fertilized by swine wastes could be of great concern to the general public. This research demonstrated the contribution of swine wastes to the occurrence and development of antibiotic resistance determinants in the receiving environments and potential risks to food safety and human health. Copyright © 2016 Elsevier Ltd. All rights reserved.

Transcriptomic Analysis of the Adaptation of Listeria monocytogenes to Lagoon and Soil Matrices Associated with a Piggery Environment: Comparison of Expression Profiles

PubMed Central

Vivant, Anne-Laure; Desneux, Jeremy; Pourcher, Anne-Marie; Piveteau, Pascal

2017-01-01

Understanding how Listeria monocytogenes, the causative agent of listeriosis, adapts to the environment is crucial. Adaptation to new matrices requires regulation of gene expression. To determine how the pathogen adapts to lagoon effluent and soil, two matrices where L. monocytogenes has been isolated, we compared the transcriptomes of L. monocytogenes CIP 110868 20 min and 24 h after its transfer to effluent and soil extract. Results showed major variations in the transcriptome of L. monocytogenes in the lagoon effluent but only minor modifications in the soil. In both the lagoon effluent and in the soil, genes involved in mobility and chemotaxis and in the transport of carbohydrates were the most frequently represented in the set of genes with higher transcript levels, and genes with phage-related functions were the most represented in the set of genes with lower transcript levels. A modification of the cell envelop was only found in the lagoon environment. Finally, the differential analysis included a large proportion of regulators, regulons, and ncRNAs. PMID:29018416

Transcriptomic Analysis of the Adaptation of Listeria monocytogenes to Lagoon and Soil Matrices Associated with a Piggery Environment: Comparison of Expression Profiles.

PubMed

Vivant, Anne-Laure; Desneux, Jeremy; Pourcher, Anne-Marie; Piveteau, Pascal

2017-01-01

Understanding how Listeria monocytogenes , the causative agent of listeriosis, adapts to the environment is crucial. Adaptation to new matrices requires regulation of gene expression. To determine how the pathogen adapts to lagoon effluent and soil, two matrices where L. monocytogenes has been isolated, we compared the transcriptomes of L. monocytogenes CIP 110868 20 min and 24 h after its transfer to effluent and soil extract. Results showed major variations in the transcriptome of L. monocytogenes in the lagoon effluent but only minor modifications in the soil. In both the lagoon effluent and in the soil, genes involved in mobility and chemotaxis and in the transport of carbohydrates were the most frequently represented in the set of genes with higher transcript levels, and genes with phage-related functions were the most represented in the set of genes with lower transcript levels. A modification of the cell envelop was only found in the lagoon environment. Finally, the differential analysis included a large proportion of regulators, regulons, and ncRNAs.

Plant diversity and root traits benefit physical properties key to soil function in grasslands.

PubMed

Gould, Iain J; Quinton, John N; Weigelt, Alexandra; De Deyn, Gerlinde B; Bardgett, Richard D

2016-09-01

Plant diversity loss impairs ecosystem functioning, including important effects on soil. Most studies that have explored plant diversity effects belowground, however, have largely focused on biological processes. As such, our understanding of how plant diversity impacts the soil physical environment remains limited, despite the fundamental role soil physical structure plays in ensuring soil function and ecosystem service provision. Here, in both a glasshouse and a long-term field study, we show that high plant diversity in grassland systems increases soil aggregate stability, a vital structural property of soil, and that root traits play a major role in determining diversity effects. We also reveal that the presence of particular plant species within mixed communities affects an even wider range of soil physical processes, including hydrology and soil strength regimes. Our results indicate that alongside well-documented effects on ecosystem functioning, plant diversity and root traits also benefit essential soil physical properties. © 2016 The Authors Ecology Letters published by CNRS and John Wiley & Sons Ltd.

Responses of Roadside Soil Cation Pools to Vehicular Emission Deposition in Southern California

NASA Astrophysics Data System (ADS)

Rossi, R.; Bain, D. J.; Jenerette, D.; Clarke, L. W.; Wilson, K.

2013-12-01

Roadside soils are heavily loaded with NO3- due to vehicular emissions. This deposition likely acidifies these soils, potentially mobilizing cationic species from soil exchange sites. Acidification driven mobilization is well documented in forest soils, but poorly understood in roadside soils. Metal concentrations in park and garden soils collected from Southern California were examined across gradients of soil chemistry, road network density, climate, and geology to examine cation mobilization effects. In our samples, soil pH is not clearly related to distance from the roadside or underlying geology. However, the depletion of several elements (Al, K) is clearly observed in near-road environments. These depletion trends occur despite contrary trends, including increased soil surface areas and soil organic matter in near-road environments. Additionally, inputs from the weathering of road building materials appear to affect soil chemistry. For example, soil Ca patterns remain relatively consistent relative to roads, suggesting Ca bearing weathering products replenish soil Ca pools in near-road areas. Simple mixing models constructed using elemental ratios are consistent with road material Ca source contributions. Observed near-road patterns in soil chemistry likely influence local ecological function, shifting plant communities and soil functions. Clear understanding of these shifts is essential to the effective use of green infrastructure and other strategies utilized to control road-sourced nutrients. This analytical framework can be applied globally as road networks continue to expand and affect larger ecosystems.

Survival and persistence of non-pathogenic Escherichia coli and attenuated Escherichia coli O157:H7 in soils amended with animal manure in a greenhouse environment

USDA-ARS?s Scientific Manuscript database

Biological soil amendments (BSA's), including dairy cattle, poultry litter, and horse manure, play an important role in agriculture but may contain pathogens that can contaminate raw or ready-to-eat fruit and vegetable crops that are consumed raw. Proposed FDA standards include a 90- or 120-day inte...

Weaving Common Threads: Reaching out to American Indians and Native Peoples of Alaska and the Pacific Islands

NASA Technical Reports Server (NTRS)

2002-01-01

This report outlines the activities of the GLOBE (Global Learning and Observations to Benefit the Environment) Train-the-Trainer Workshop. Educators were introduced to the GLOBE protocols for Atmosphere, Hydrology, Soil and Land Cover. These protocols included measurement of pH, temperature, precipitation, salinity, and soil moisture content. Each topic included implementation plans and learning activities.

Teaching Global Perspectives in a Rural Environment.

ERIC Educational Resources Information Center

Lind, Mary Ann

1980-01-01

Rural students can understand global perspectives by developing pride as food providers who share "kinship of the soil" with the developing world. Important lessons include man's dependence on the land; philosophy of environmental protection; agricultural technology; political influence over soil use; and five factors controlling crop production.…

Plant-Associated Bacterial Degradation of Toxic Organic Compounds in Soil

PubMed Central

McGuinness, Martina; Dowling, David

2009-01-01

A number of toxic synthetic organic compounds can contaminate environmental soil through either local (e.g., industrial) or diffuse (e.g., agricultural) contamination. Increased levels of these toxic organic compounds in the environment have been associated with human health risks including cancer. Plant-associated bacteria, such as endophytic bacteria (non-pathogenic bacteria that occur naturally in plants) and rhizospheric bacteria (bacteria that live on and near the roots of plants), have been shown to contribute to biodegradation of toxic organic compounds in contaminated soil and could have potential for improving phytoremediation. Endophytic and rhizospheric bacterial degradation of toxic organic compounds (either naturally occurring or genetically enhanced) in contaminated soil in the environment could have positive implications for human health worldwide and is the subject of this review. PMID:19742157

Archaeal Diversity in Waters from Deep South African Gold Mines

PubMed Central

Takai, Ken; Moser, Duane P.; DeFlaun, Mary; Onstott, Tullis C.; Fredrickson, James K.

2001-01-01

A culture-independent molecular analysis of archaeal communities in waters collected from deep South African gold mines was performed by performing a PCR-mediated terminal restriction fragment length polymorphism (T-RFLP) analysis of rRNA genes (rDNA) in conjunction with a sequencing analysis of archaeal rDNA clone libraries. The water samples used represented various environments, including deep fissure water, mine service water, and water from an overlying dolomite aquifer. T-RFLP analysis revealed that the ribotype distribution of archaea varied with the source of water. The archaeal communities in the deep gold mine environments exhibited great phylogenetic diversity; the majority of the members were most closely related to uncultivated species. Some archaeal rDNA clones obtained from mine service water and dolomite aquifer water samples were most closely related to environmental rDNA clones from surface soil (soil clones) and marine environments (marine group I [MGI]). Other clones exhibited intermediate phylogenetic affiliation between soil clones and MGI in the Crenarchaeota. Fissure water samples, derived from active or dormant geothermal environments, yielded archaeal sequences that exhibited novel phylogeny, including a novel lineage of Euryarchaeota. These results suggest that deep South African gold mines harbor novel archaeal communities distinct from those observed in other environments. Based on the phylogenetic analysis of archaeal strains and rDNA clones, including the newly discovered archaeal rDNA clones, the evolutionary relationship and the phylogenetic organization of the domain Archaea are reevaluated. PMID:11722932

Assessing the potential for rhizoremediation of PCB contaminated soils in northern regions using native species

PubMed Central

Slater, Heather; Gouin, Todd; Leigh, Mary Beth

2011-01-01

Rhizosphere bioremediation of polychlorinated biphenyls (PCBs) offers a potentially inexpensive approach to remediating contaminated soils that is particularly attractive in remote regions including the Arctic. We assessed the abilities of two tree species native to Alaska, Salix alaxensis (felt-leaf willow) and Picea glauca (white spruce), to promote microbial biodegradation of PCBs via the release of phytochemicals upon fine root death. Crushed fine roots, biphenyl (PCB analogue) or salicylate (willow secondary compound) were added to microcosms containing soil spiked with PCBs and resultant PCB disappearance, soil toxicity and microbial community changes were examined. After 180 d, soil treated with willow root crushates showed a significantly greater PCB loss than untreated soils for some PCB congeners, including the toxic congeners, PCB 77, 105 and 169, and showed a similar PCB loss pattern (in both extent of degradation and congeners degraded) to biphenyl-treated microcosms. Neither P. glauca (white spruce) roots nor salicylate enhanced PCB loss, indicating that biostimulation is plant species specific and was not mediated by salicylate. Soil toxicity assessed using the Microtox bioassay indicated that the willow treatment resulted in a less toxic soil environment. Molecular microbial community analyses indicated that biphenyl and salicylate promoted shifts in microbial community structure and composition that differed distinctly from each other and from the crushed root treatments. The biphenyl utilizing bacterium, Cupriavidus spp. was isolated from the soil. The findings suggest that S. alaxensis may be an effective plant for rhizoremediation by altering microbial community structure, enhancing the loss of some PCB congeners and reducing the toxicity of the soil environment. PMID:21596420

USING CONONICAL CORRELATION TO DETECT ASSOCIATION OF LANDSCAPE METRICS WITH WATER BIOLOGICAL AND CHEMICAL PROPERTIES IN SAVANNAH RIVER BASIN

EPA Science Inventory

Surface water quality is related to conditions in the surrounding geophysical environment, including soils, landcover, and anthropogenic activities. For example, clearing vegetation exposes soil to increased water/wind erosion, resulting in increased sediment loads to surface wat...

Soil - A necessary resource for our future

USDA-ARS?s Scientific Manuscript database

Fertile or degraded soils have been the basis of the rise or fall of civilizations throughout history. They have been the engine that powered the rise of many countries including our own and the fall of those who were not good stewards of their environment or suffered insurmountable setbacks, such a...

Test Operations Procedure (TOP) 1-1-062 Environmental Effects Data Collection

DTIC Science & Technology

2008-09-12

this procedure. 11. ESTIMATION DESCRIPTION The prime example of an empirically based model is the Universal Soil Loss Equation ( USLE ) developed...impacts to human health and welfare and to the natural environment. The type of data collected might include noise levels, soil erosion, and...uptake relevant to flora/fauna and the soil erosion effects of proposed testing. c. Plan to identify any modifications/alternatives implemented

Modelling of deformation of underground tunnel lining, interacting with water-saturated soil

NASA Astrophysics Data System (ADS)

Berezhnoi, D. V.; Balafendieva, I. S.; Sachenkov, A. A.; Sekaeva, L. R.

2016-11-01

Built finite element method of calculating the deformation of underground tunnel lining, interacting with dry and water-saturated soils. To simulate the interaction between the lining and soils environments, including physical and non-linear, a special "contact" finite element, which allows to consider all cases of interaction between the contacting surfaces. It solved a number of problems of deformation with the ground subway tunnel lining rings.

Spatial and temporal variability of soil moisture on the field with and without plants*

NASA Astrophysics Data System (ADS)

Usowicz, B.; Marczewski, W.; Usowicz, J. B.

2012-04-01

Spatial and temporal variability of the natural environment is its inherent and unavoidable feature. Every element of the environment is characterized by its own variability. One of the kinds of variability in the natural environment is the variability of the soil environment. To acquire better and deeper knowledge and understanding of the temporal and spatial variability of the physical, chemical and biological features of the soil environment, we should determine the causes that induce a given variability. Relatively stable features of soil include its texture and mineral composition; examples of those variables in time are the soil pH or organic matter content; an example of a feature with strong dynamics is the soil temperature and moisture content. The aim of this study was to identify the variability of soil moisture on the field with and without plants using geostatistical methods. The soil moisture measurements were taken on the object with plant canopy and without plants (as reference). The measurements of soil moisture and meteorological components were taken within the period of April-July. The TDR moisture sensors covered 5 cm soil layers and were installed in the plots in the soil layers of 0-0.05, 0.05-0.1, 0.1-0.15, 0.2-0.25, 0.3-0.35, 0.4-0.45, 0.5-0.55, 0.8-0.85 m. Measurements of soil moisture were taken once a day, in the afternoon hours. For the determination of reciprocal correlation, precipitation data and data from soil moisture measurements with the TDR meter were used. Calculations of reciprocal correlation of precipitation and soil moisture at various depths were made for three objects - spring barley, rye, and bare soil, at the level of significance of p<0.05. No significant reciprocal correlation was found between the precipitation and soil moisture in the soil profile for any of the objects studied. Although the correlation analysis indicates a lack of correlation between the variables under consideration, observation of the soil moisture runs in particular objects and of precipitation distribution shows clearly that rainfall has an effect on the soil moisture. The amount of precipitation water that increased the soil moisture depended on the strength of the rainfall, on the hydrological properties of the soil (primarily the soil density), the status of the plant cover, and surface runoff. Basing on the precipitation distribution and on the soil moisture runs, an attempt was made at finding a temporal and spatial relationship between those variables, employing for the purpose the geostatistical methods which permit time and space to be included in the analysis. The geostatistical parameters determined showed the temporal dependence of moisture distribution in the soil profile, with the autocorrelation radius increasing with increasing depth in the profile. The highest values of the radius were observed in the plots with plant cover below the arable horizon, and the lowest in the arable horizon on the barley and fallow plots. The fractal dimensions showed a clear decrease in values with increasing depth in the plots with plant cover, while in the bare plots they were relatively constant within the soil profile under study. Therefore, they indicated that the temporal distribution of soil moisture within the soil profile in the bare field was more random in character than in the plots with plants. The results obtained and the analyses indicate that the moisture in the soil profile, its variability and determination, are significantly affected by the type and condition of plant canopy. The differentiation in moisture content between the plots studied resulted from different precipitation interception and different intensity of water uptake by the roots. * The work was financially supported in part by the ESA Programme for European Cooperating States (PECS), No.98084 "SWEX-R, Soil Water and Energy Exchange/Research", AO-3275.

Weathering profiles in soils and rocks on Earth and Mars

NASA Astrophysics Data System (ADS)

Hausrath, E.; Adcock, C. T.; Bamisile, T.; Baumeister, J. L.; Gainey, S.; Ralston, S. J.; Steiner, M.; Tu, V.

2017-12-01

Interactions of liquid water with rock, soil, or sediments can result in significant chemical and mineralogical changes with depth. These changes can include transformation from one phase to another as well as translocation, addition, and loss of material. The resulting chemical and mineralogical depth profiles can record characteristics of the interacting liquid water such as pH, temperature, duration, and abundance. We use a combined field, laboratory, and modeling approach to interpret the environmental conditions preserved in soils and rocks. We study depth profiles in terrestrial field environments; perform dissolution experiments of primary and secondary phases important in soil environments; and perform numerical modeling to quantitatively interpret weathering environments. In our field studies we have measured time-integrated basaltic mineral dissolution rates, and interpreted the impact of pH and temperature on weathering in basaltic and serpentine-containing rocks and soils. These results help us interpret fundamental processes occurring in soils on Earth and on Mars, and can also be used to inform numerical modeling and laboratory experiments. Our laboratory experiments provide fundamental kinetic data to interpret processes occurring in soils. We have measured dissolution rates of Mars-relevant phosphate minerals, clay minerals, and amorphous phases, as well as dissolution rates under specific Mars-relevant conditions such as in concentrated brines. Finally, reactive transport modeling allows a quantitative interpretation of the kinetic, thermodynamic, and transport processes occurring in soil environments. Such modeling allows the testing of conditions under longer time frames and under different conditions than might be possible under either terrestrial field or laboratory conditions. We have used modeling to examine the weathering of basalt, olivine, carbonate, phosphate, and clay minerals, and placed constraints on the duration, pH, and solution chemistry of past aqueous alteration occurring on Mars.

Non-human C. difficile Reservoirs and Sources: Animals, Food, Environment.

PubMed

Rodriguez Diaz, Cristina; Seyboldt, Christian; Rupnik, Maja

2018-01-01

Clostridium difficile is ubiquitous and is found in humans, animals and in variety of environments. The substantial overlap of ribotypes between all three main reservoirs suggests the extensive transmissions. Here we give the overview of European studies investigating farm, companion and wild animals, food and environments including water, soil, sediment, waste water treatment plants, biogas plants, air and households. Studies in Europe are more numerous especially in last couple of years, but are still fragmented in terms of countries, animal species or type of environment covered. Soil seem to be the habitat of divergent unusual lineages of C. difficile. But the most important aspect of animals and environment is their role in C. difficile transmissions and their potential as a source for human infection is discussed.

77 FR 70155 - Notice of Intent To Prepare an Environmental Impact Statement for the Disposal and Reuse of the...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-23

... human and natural environments, including potential impacts on topography, geology and soils, water... by mail or email by November 30, 2012, to Mr. Matt Butwin, Ecology and Environment, Inc., 348...

77 FR 64110 - Notice of Intent To Prepare an Environmental Impact Statement for the Disposal and Reuse of the...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-18

... human and natural environments, including potential impacts on topography, geology and soils, water... or email by October 24, 2012, to Mr. Matt Butwin, Ecology and Environment, Inc., 348 Southport Circle...

Animating the biodynamics of soil thickness using process vector analysis: A dynamic denudation approach to soil formation

USGS Publications Warehouse

Johnson, D.L.; Domier, J.E.J.; Johnson, D.N.

2005-01-01

This paper expands the dynamic denudation framework of landscape evolution by providing new process insights and details on how soil and its signature morphological feature, the biomantle, form and function in the environment. We examine soils and their biomantles from disparate parts of the world, from the tropics through midlatitudes and hyperarid through perhumid, a range that exhibits varying environments for, and of, life. We then explicate the process pathways that cause soils to thicken and thin, and to even disappear, then reform. We do this by examining thickness relationships, where soil thickness stand biomantle thickness bt are functions of upbuilding u and deepening d minus removal r processes, hence st/bt=f(u+d-r). Upbuilding has two subsets, u1, which includes all exogenous (allochthonous-outside) mineral and/or organic inputs to the soil system, and u2, which includes all endogenous (autochthonous-in situ) processes and productions, including weathering. Exogenous u1 inputs include eolian and slopewash inputs (sedimentations) of mineral and organic materials, mass wasting accumulations and the like. Endogenous u2 processes and productions include the sum of in situ bioturbations, biosynthetic productions, organic accumulations, biovoid productions, weathering and volume increases caused by their sum. Endogenous upbuildings, which dominantly occur in the biomantle, are basically biodynamic bd processes and productions, hence u2=bd. Therefore, if exogenous upbuildings u1 are minimal or zero, then biomantle thickness bt is expressed by bt=f(u2-r) or bt=f(bd-r). Drawing on these relationships, we employ a graphic-conceptual device called process vector analysis in a digital animation (see supplementary materials or cf. https://netfiles.uiuc.edu/jdomier/www/temp/ biomantle.html) that illustrates the main pathways that form both Earth's soil and its unique epidermis, the biomantle. We then discuss the main elements of the animation using still frames that represent thickness turning points. We end by encouraging researchers, instructors and students to view Earth's landforms and soils as integrated dynamic entities that are constantly coevolving elements of a global subaerial-subaqueous continuum. ?? 2004 Elsevier B.V. All rights reserved.

Soil-pipe interaction modeling for pipe behavior prediction with super learning based methods

NASA Astrophysics Data System (ADS)

Shi, Fang; Peng, Xiang; Liu, Huan; Hu, Yafei; Liu, Zheng; Li, Eric

2018-03-01

Underground pipelines are subject to severe distress from the surrounding expansive soil. To investigate the structural response of water mains to varying soil movements, field data, including pipe wall strains in situ soil water content, soil pressure and temperature, was collected. The research on monitoring data analysis has been reported, but the relationship between soil properties and pipe deformation has not been well-interpreted. To characterize the relationship between soil property and pipe deformation, this paper presents a super learning based approach combining feature selection algorithms to predict the water mains structural behavior in different soil environments. Furthermore, automatic variable selection method, e.i. recursive feature elimination algorithm, were used to identify the critical predictors contributing to the pipe deformations. To investigate the adaptability of super learning to different predictive models, this research employed super learning based methods to three different datasets. The predictive performance was evaluated by R-squared, root-mean-square error and mean absolute error. Based on the prediction performance evaluation, the superiority of super learning was validated and demonstrated by predicting three types of pipe deformations accurately. In addition, a comprehensive understand of the water mains working environments becomes possible.

1100 years of human impact on woodland and soils in Kjarardalur, West Iceland

NASA Astrophysics Data System (ADS)

Gísladóttir, Guðrún; Erlendsson, Egill; Lal, Rattan

2013-04-01

Prior to the Norse settlement of Iceland around AD 874 climate was the principal control of ecosystem variability. Since then, drastic changes have been imposed on the island's ecosystem through human activities. Unsustainable land use has reduced vegetation coverage, altered floral composition and accelerated soil erosion, especially in conjunction with harsh climate. Healthy ecosystem, soil and vegetation, is not only an important resource to meet human demands but also a prominent sink of atmospheric CO2. In contrast, soil erosion and land degradation are major sources of atmospheric CO2. This study discusses the impact of human activities and climate change on vegetation, soil erosion, and soil organic carbon (SOC) in West Iceland. Analyses conducted include pollen in Histosols, soil properties, soil accumulation rates and SOC in Histosols and Andosols. Our data demonstrate a pre-settlement landscape that was not entirely stable, where relatively small differences in climate may have caused subtle changes to the terrestrial environment. However, the early colonists and subsequent occupants altered the environment significantly. The magnitude of alteration was spatially variable depending on land management. The vegetation and soil data demonstrate a swift transformation of environmental conditions across AD 874. The most profound impacts include reduction in birch woodland and concurrent decline of important habitat for fragile understory, which facilitated soil exposure and reduced soil quality. After about 300 years, land degradation-anticipated management towards enhanced sustainability was probably adopted at one of the farming properties in the study area, allowing for soil recovery after a period of drastic decline. At other properties unsustainable land use continued to degrade the terrestrial ecosystem. The late-Medieval climatic change and introduction of the Little-Ice age exerted added strain on the environments over the entire area, resulting in further soil degradation. The property where sustainable land use had been adopted preserved woodland cover and maintained greater soil quality than elsewhere in the valley, where thresholds of ecosystem resilience were crossed. Unsustainable land use over 1100 years caused vegetation denudation that accelerated soil erosion, with attendant redistribution of soil over the landscape, and decline in its quality. Vegetated areas became important sinks for wind-transported soils, as evidenced by increase in deposition rate and higher bulk density. This led to an increase in susceptibility to soil erosion, and decline in SOC content. Despite decrease in SOC content, the high sedimentation rate and elevated bulk weight resulted in higher SOC sequestration at these sites, even though soil quality declined. The potential soil C sequestration in adjacent sparsely or devegetated soils were highly impaired and along with soil mass losses these areas became sources of anthropogenic CO2.

Veterinary medicines in the environment.

PubMed

Boxall, A B A; Fogg, L A; Blackwell, P A; Kay, P; Pemberton, E J; Croxford, A

2004-01-01

The impact of veterinary medicines on the environment will depend on a number of factors including physicochemical properties, amount used and method of administration, treatment type and dose, animal husbandry practices, manure storage and handling practices, metabolism within the animal, and degradation rates in manure and slurry. Once released to the environment, other factors such as soil type, climate, and ecotoxicity also determine the environmental impact of the compound. The importance of individual routes into the environment for different types of veterinary medicines varies according to the type of treatment and livestock category. Treatments used in aquaculture have a high potential to reach the aquatic environment. The main routes of entry to the terrestrial environment are from the use of veterinary medicines in intensively reared livestock, via the application of slurry and manure to land, and by the use of veterinary medicines in pasture-reared animals where pharmaceutical residues are excreted directly into the environment. Veterinary medicines applied to land via spreading of slurry may also enter the aquatic environment indirectly via surface runoff or leaching to groundwater. It is likely that topical treatments have greater potential to be released to the environment than treatments administered orally or by injection. Inputs from the manufacturing process, companion animal treatments, and disposal are likely to be minimal in comparison. Monitoring studies demonstrate that veterinary medicines do enter the environment, with sheep dip chemicals, antibiotics, sealice treatments, and anthelmintics being measured in soils, groundwater, surface waters, sediment, or biota. Maximum concentrations vary across chemical classes, with very high concentrations being reported for the sheep dip chemicals. The degree to which veterinary medicines may adsorb to particulates varies widely. Partition coefficients (K(d)) range from low (0.61 L kg(-1)) to high (6000 L kg(-1)). The variation in partitioning for many of the compounds in different soils was significant (up to a factor of 30), but these differences could be not be explained by normalization to the organic carbon content of the soils. Thus, to arrive at a realistic assessment of the availability of veterinary medicines for transport through the soil and uptake into soil organisms, the K(oc) (which is used in many of the exposure models) may not be an appropriate measure. Transport of particle-associated substances from soil to surface waters has also been demonstrated. Veterinary medicines can persist in soils for days to years, and half-lives are influenced by a range of factors including temperature, pH, and the presence of manure. The persistence of major groups of veterinary medicines in soil, manure, slurry, and water varies across and within classes. Ecotoxicity data were available for a wide range of veterinary medicines. The acute and chronic effects of avermectins and sheep dip chemicals on aquatic organisms are well documented, and these substances are known to be toxic to many organisms at low concentrations (ng L(-1) to microg L(-1)). Concerns have also been raised about the possibility of indirect effects of these substances on predatory species (e.g., birds and bats). Data for other groups indicate that toxicity values are generally in the mg L(-1) range. For the antibiotics, toxicity is greater for certain species of algae and marine bacteria. Generally, toxicity values for antibacterial agents were significantly higher than reported environmental concentrations. However, because of a lack of appropriate toxicity data, it is difficult to assess the environmental significance of these observations with regard to subtle long-term effects.

49 CFR 192.455 - External corrosion control: Buried or submerged pipelines installed after July 31, 1971.

Code of Federal Regulations, 2010 CFR

2010-10-01

... minimum, soil resistivity measurements and tests for corrosion accelerating bacteria, that a corrosive environment does not exist. However, within 6 months after an installation made pursuant to the preceding sentence, the operator shall conduct tests, including pipe-to-soil potential measurements with respect to...

Contamination of environment in the road surroudings - impact of road salting on Norway spruce (Picea abies) and Scots pine (Pinus sylvestris)

NASA Astrophysics Data System (ADS)

Hegrová, Jitka; Steiner, Oliver; Goessler, Walter; Tanda, Stefan; Anděl, Petr

2017-09-01

A comprehensive overview of the influence of transport on the environment is presented in this study. The complex analysis of soil and needle samples provides an extensive set of data, which presents elemental contamination of the environment near roads. Traffic pollution (including winter road treatment) has a significant negative influence on our environment. Besides sodium and chlorine from winter maintenance many other elements are emitted into the environment. Three possible sources of contamination are assumed for environmental contamination evaluation: car emission, winter maintenance and abrasion from breaks and clutches. The chemical analysis focused on the description of samples from inorganic point of view. The influence of the contamination potential on the sodium and chlorine content in the samples of 1st year-old and 2nd year-old needles of Norway spruce (Picea abies) and Scots pine (Pinus sylvestris) is discussed. Additional soil samples were taken from each sampling site and analyzed to get insight in the sodium and chlorine distribution. Statistical evaluation was used for interpretation of complex interaction patterns between element concentrations in different aged needles based on localities character including distance from the road and element concentration in soils. This species of needles were chosen because of its heightened sensitivity towards salinization. The study was conducted in different parts of the Czech Republic. The resulting database is a source of valuable information about the influence of transport on the environment.

Soil formation: Chapter 6

USGS Publications Warehouse

Goldhaber, Martin B.; Banwart, Steven A.

2015-01-01

Soil formation reflects the complex interaction of many factors, among the most important of which are (i) the nature of the soil parent material, (ii) regional climate, (iii) organisms, including humans, (iv) topography and (v) time. These processes operate in Earth's critical zone; the thin veneer of our planet where rock meets life. Understanding the operation of these soil-forming factors requires an interdisciplinary approach and is a necessary predicate to charactering soil processes and functions, mitigating soil degradation and adapting soil management to environmental change. In this chapter, we discuss how these soil-forming factors operate both singly and in concert in natural and human modified environments. We emphasize the role that soil organic matter plays in these processes to provide context for understanding the benefits that it bestows on humanity.

Assessing the potential for rhizoremediation of PCB contaminated soils in northern regions using native tree species.

PubMed

Slater, Heather; Gouin, Todd; Leigh, Mary Beth

2011-06-01

Rhizosphere bioremediation of polychlorinated biphenyls (PCBs) offers a potentially inexpensive approach to remediating contaminated soils that is particularly attractive in remote regions including the Arctic. We assessed the abilities of two tree species native to Alaska, Salix alaxensis (felt-leaf willow) and Picea glauca (white spruce), to promote microbial biodegradation of PCBs via the release of phytochemicals upon fine root death. Crushed fine roots, biphenyl (PCB analogue) or salicylate (willow secondary compound) were added to microcosms containing soil spiked with PCBs and resultant PCB disappearance, soil toxicity and microbial community changes were examined. After 180d, soil treated with willow root crushates showed a significantly greater PCB loss than untreated soils for some PCB congeners, including the toxic congeners, PCB 77, 105 and 169, and showed a similar PCB loss pattern (in both extent of degradation and congeners degraded) to biphenyl-treated microcosms. Neither P. glauca (white spruce) roots nor salicylate enhanced PCB loss, indicating that biostimulation is plant species specific and was not mediated by salicylate. Soil toxicity assessed using the Microtox bioassay indicated that the willow treatment resulted in a less toxic soil environment. Molecular microbial community analyses indicated that biphenyl and salicylate promoted shifts in microbial community structure and composition that differed distinctly from each other and from the crushed root treatments. The biphenyl utilizing bacterium, Cupriavidus spp. was isolated from the soil. The findings suggest that S. alaxensis may be an effective plant for rhizoremediation by altering microbial community structure, enhancing the loss of some PCB congeners and reducing the toxicity of the soil environment. Copyright © 2011 Elsevier Ltd. All rights reserved.

Neurotoxicity of brominated flame retardants

EPA Science Inventory

Polybrominated diphenyl ethers (PBDEs) have been commonly used as commercial flame retardants in a variety of products including plastics and textiles. Despite their decreasing usage worldwide, congeners continue to accumulate in the environment, including soil, dust, food, anima...

USGS microbiome research

USGS Publications Warehouse

Kellogg, Christina A.; Hopkins, M. Camille

2017-09-26

Microbiomes are the communities of microorganisms (for example, bacteria, viruses, and fungi) that live on, in, and around people, plants, animals, soil, water, and the atmosphere. Microbiomes are active in the functioning of diverse ecosystems, for instance, by influencing water quality, nutrient acquisition 
and stress tolerance in plants, and stability of soil and aquatic environments. Microbiome research conducted by the U.S. Geological Survey spans many of our mission areas. Key research areas include water quality, understanding climate effects on soil and permafrost, ecosystem and wildlife health, invasive species, contaminated environments to improve bioremediation, and enhancing energy production. Microbiome research will fundamentally strengthen the ability to address the global challenges of maintaining clean water, ensuring adequate food supply, meeting energy needs, and preserving human and ecosystem health.

Microbial ecology and biogeochemistry of continental Antarctic soils.

PubMed

Cowan, Don A; Makhalanyane, Thulani P; Dennis, Paul G; Hopkins, David W

2014-01-01

The Antarctica Dry Valleys are regarded as the coldest hyperarid desert system on Earth. While a wide variety of environmental stressors including very low minimum temperatures, frequent freeze-thaw cycles and low water availability impose severe limitations to life, suitable niches for abundant microbial colonization exist. Antarctic desert soils contain much higher levels of microbial diversity than previously thought. Edaphic niches, including cryptic and refuge habitats, microbial mats and permafrost soils all harbor microbial communities which drive key biogeochemical cycling processes. For example, lithobionts (hypoliths and endoliths) possess a genetic capacity for nitrogen and carbon cycling, polymer degradation, and other system processes. Nitrogen fixation rates of hypoliths, as assessed through acetylene reduction assays, suggest that these communities are a significant input source for nitrogen into these oligotrophic soils. Here we review aspects of microbial diversity in Antarctic soils with an emphasis on functionality and capacity. We assess current knowledge regarding adaptations to Antarctic soil environments and highlight the current threats to Antarctic desert soil communities.

Silvics of North America: 1. Conifers; 2. Hardwoods

Treesearch

Russell M. Burns; Barbara H. (tech. Coords.) Honkala

1990-01-01

The total environment of a tree is a complex integration of physical and biological elements. The physical elements are related to climate and soil and include radiation, precipitation, and the movement and composition of air; as well as the texture of the soil and its structure, depth, moisture capacity, drainage, nutrient content, and topographic position. Biological...

Azerbaijan: environmental conditions and outlook.

PubMed

Shelton, Napier

2003-06-01

The author describes present environmental conditions in Azerbaijan in relation to the Soviet legacy and measures taken since independence. Environmental projects have been financed largely by international organizations and foreign companies. The most serious problems are contaminants in the Caspian Sea; air, water, and soil pollution in Sumgait; illegal fishing; poor quality of drinking water; cutting of forests for fuel and pasture; overgrazing; and soil erosion and salinization. Progress in developing an environmental conscience, necessary for sustained protection of the environment, will depend most importantly on environmental education, growth of democratic institutions and attitudes that encourage both governmental and citizen responsibility for the environment, and economic development that produces a substantial middle class. Positive advances include a Constitution and laws that require protection of the environment, and individuals who speak out for environmental care. Negative factors include poverty and the present government's low priority for environmental protection.

Transfer of heavy metals through terrestrial food webs: a review.

PubMed

Gall, Jillian E; Boyd, Robert S; Rajakaruna, Nishanta

2015-04-01

Heavy metals are released into the environment by both anthropogenic and natural sources. Highly reactive and often toxic at low concentrations, they may enter soils and groundwater, bioaccumulate in food webs, and adversely affect biota. Heavy metals also may remain in the environment for years, posing long-term risks to life well after point sources of heavy metal pollution have been removed. In this review, we compile studies of the community-level effects of heavy metal pollution, including heavy metal transfer from soils to plants, microbes, invertebrates, and to both small and large mammals (including humans). Many factors contribute to heavy metal accumulation in animals including behavior, physiology, and diet. Biotic effects of heavy metals are often quite different for essential and non-essential heavy metals, and vary depending on the specific metal involved. They also differ for adapted organisms, including metallophyte plants and heavy metal-tolerant insects, which occur in naturally high-metal habitats (such as serpentine soils) and have adaptations that allow them to tolerate exposure to relatively high concentrations of some heavy metals. Some metallophyte plants are hyperaccumulators of certain heavy metals and new technologies using them to clean metal-contaminated soil (phytoextraction) may offer economically attractive solutions to some metal pollution challenges. These new technologies provide incentive to catalog and protect the unique biodiversity of habitats that have naturally high levels of heavy metals.

Soil Bacterial Diversity Is Associated with Human Population Density in Urban Greenspaces.

PubMed

Wang, Haitao; Cheng, Minying; Dsouza, Melissa; Weisenhorn, Pamela; Zheng, Tianling; Gilbert, Jack A

2018-05-01

Urban greenspaces provide extensive ecosystem services, including pollutant remediation, water management, carbon maintenance, and nutrient cycling. However, while the urban soil microbiota underpin these services, we still have limited understanding of the factors that influence their distribution. We characterized soil bacterial communities from turf-grasses associated with urban parks, streets, and residential sites across a major urban environment, including a gradient of human population density. Bacterial diversity was significantly positively correlated with the population density; and species diversity was greater in park and street soils, compared to residential soils. Population density and greenspace type also led to significant differences in the microbial community composition that was also significantly correlated with soil pH, moisture, and texture. Co-occurrence network analysis revealed that microbial guilds in urban soils were well correlated. Abundant soil microbes in high density population areas had fewer interactions, while abundant bacteria in high moisture soils had more interactions. These results indicate the significant influence of changes in urban demographics and land-use on soil microbial communities. As urbanization is rapidly growing across the planet, it is important to improve our understanding of the consequences of urban zoning on the soil microbiota.

Bioaugmentation of Soil Contaminated with Azoxystrobin.

PubMed

Baćmaga, Małgorzata; Wyszkowska, Jadwiga; Kucharski, Jan

2017-01-01

The presence of fungicides in the natural environment, either resulting from deliberate actions or not, has become a serious threat to many ecosystems, including soil. This can be prevented by taking appropriate measures to clear the environment of organic contamination, including fungicides. Therefore, a study was conducted aimed at determining the effect of bioaugmentation of soil exposed to azoxystrobin on its degradation and activity of selected enzymes (dehydrogenases, catalase, urease, acidic phosphatase, alkaline phosphatase). A model experiment was conducted for 90 days on two types of soil: loamy sand (pH KCl -5.6) and sandy loam (pH KCl -7.0), which were contaminated by azoxystrobin at 22.50 mg kg -1 DM of soil and inoculated with a specific consortium of microorganisms. Four strains of bacteria were used in the experiment ( Bacillus sp. LM655314.1, B. cereus KC848897.1, B. weihenstephanensis KF831381.1, B. megaterium KJ843149.1) and two strains of mould fungi ( Aphanoascus terreus AB861677.1, A. fulvescens JN943451.1). Inoculation of soil with the consortium of microorganisms accelerated the degradation of azoxystrobin. The isolated microorganisms were more active in loamy sand because within 90 days azoxystrobin was degraded by 24% ( Bacillus sp., B. cereus , B. weihenstephanensis , B. megaterium ) to 78% ( Aphanoascus terreus , A. fulvescens ). In sandy loam, azoxystrobin was degraded by 9% ( Aphanoascus terreus , A. fulvescens ) to 29% ( Bacillus sp., B. cereus , B. weihenstephanensis , B. megaterium and Aphanoascus terreus , A. fulvescens ). The activity of soil enzymes was also changed as a result of inoculation of soil with microorganisms. The activity of all of the enzymes under study was found to have increased when soil augmentation was performed.

Explanation of pole blight from responses of seedlings grown in modified environments

Treesearch

Charles D. Leaphart; Ed F. Wicker

1966-01-01

Seedlings of Douglas fir, grand fir, western larch, western red cedar, and western white pine were grown in modified environments for four growing seasons to see whether characteristic growth responses of roots and shoots might suggest a cause for pole blight of white pine. Environments included three soil profiles (topsoil, hardpan, and rock) and two moisture regimes...

Optimization of a Sample Processing Protocol for Recovery of ...

EPA Pesticide Factsheets

Journal Article Following a release of Bacillus anthracis spores into the environment, there is a potential for lasting environmental contamination in soils. There is a need for detection protocols for B. anthracis in environmental matrices. However, identification of B. anthracis within a soil is a difficult task. Processing soil samples helps to remove debris, chemical components, and biological impurities that can interfere with microbiological detection. This study aimed to optimize a previously used indirect processing protocol, which included a series of washing and centrifugation steps.

Effect of soil properties on the toxicity of Pb: assessment of the appropriateness of guideline values.

PubMed

Romero-Freire, A; Martin Peinado, F J; van Gestel, C A M

2015-05-30

Soil contamination with lead is a worldwide problem. Pb can cause adverse effects, but its mobility and availability in the terrestrial environment are strongly controlled by soil properties. The present study investigated the influence of different soil properties on the solubility of lead in laboratory spiked soils, and its toxicity in three bioassays, including Lactuca sativa root elongation and Vibrio fischeri illumination tests applied to aqueous extracts and basal soil respiration assays. Final aim was to compare soil-dependent toxicity with guideline values. The L. sativa bioassay proved to be more sensitive to Pb toxicity than the V. fischeri and soil respiration tests. Toxicity was significantly correlated with soil properties, with soil pH, carbonate and organic carbon content being the most important factors. Therefore, these variables should be considered when defining guideline values. Copyright © 2015 Elsevier B.V. All rights reserved.

Life on Guam: Geology. 1977 Edition.

ERIC Educational Resources Information Center

Elkins, Gail; And Others

As part of an updated series of activity oriented educational materials dealing with aspects of the Guam environment, this publication focuses on the physical environment of Guam through an introduction to the geology of Guam. Contents include the formation of Guam, weathering and erosion, earthquakes, soil, and water. Activities investigate…

Science Action Labs Part 2: Environment.

ERIC Educational Resources Information Center

Shevick, Ed; Shevick, Florence, Ed.

This book contains innovative hands-on science laboratory activities designed to teach 4th- through 9th-graders about the environment. The background materials and instructions included in each activity are written for students to work together in teams. Activities cover subjects such as smog, symbiosis, soil, trees, ecosystems, recycling,…

Construction of a Rye BAC Library for Utilization in Physical Mapping of an Aluminum Tolerance Gene Complex

USDA-ARS?s Scientific Manuscript database

Aluminium, the most abundant metal on earth, is highly toxic to plant growth and is found in about 2.5 billion hectares of acid soils, including more than 130 million hectares in the United States. Many of the world’s farmers are living on marginal soils that offer a stressful environment for plant ...

Enhancing Readiness Through Environmental Quality Technology

DTIC Science & Technology

1996-05-01

mercury . Up coming technologies for heavy metal soil contamination include phytoremediation and electrokinetics. Plants have also been shown to uptake... phytoremediation could be that process. Many plants have been found that have a nitroreductase enzyme. These plants can degrade explosive contaminants. This... phytoremediation in a wetland environment for explosive contaminated groundwater. But, this could be transferred directly to soils if proven successful

Degradation and adsorption of selected pharmaceuticals and personal care products (PPCPs) in agricultural soils.

PubMed

Xu, Jian; Wu, Laosheng; Chang, Andrew C

2009-11-01

Pharmaceuticals and personal care products (PPCPs) are emerging contaminants in the environment, which have drawn popular concerns recently. Most studies on the environmental fate of PPCPs have focused on their behaviors during wastewater treatment processes, in aquatic environments, and in the sludge, however, little is known about their behavior in agricultural soils. In this study, adsorption and degradation of six selected PPCPs, including clofibric acid, ibuprofen, naproxen, triclosan, diclofenac and bisphenol A have been investigated in the laboratory using four US agricultural soils associated with reclaimed wastewater reuse. Adsorption test using a batch equilibrium method demonstrated that adsorption of all tested chemicals in soils could be well described with Freundlich equation, and their adsorption affinity on soil followed the order of triclosan>bisphenol A>clofibric acid>naproxen>diclofenac>ibuprofen. Retardation factor (R(F)) suggested that ibuprofen had potential to move downward with percolating water, while triclosan and bisphenol A were readily retarded in soils. Degradation of selected PPCPs in soils generally followed first-order exponential decay kinetics, with half-lives ranging from 0.81 to 20.44 d. Degradation of PPCPs in soils appeared to be influenced by the soil organic matter and clay contents. Sterilization generally decreased the degradation rates, indicating microbial activity played a significant role in the degradation in soils. The degradation rate constant decreased with increasing initial chemical concentrations in soil, implying that the microbial activity was inhibited with high chemical loading levels.

Relationships between soil and leaf mineral composition are element-specific, environment-dependent and geographically structured in the emerging model Arabidopsis halleri.

PubMed

Stein, Ricardo J; Höreth, Stephan; de Melo, J Romário F; Syllwasschy, Lara; Lee, Gwonjin; Garbin, Mário L; Clemens, Stephan; Krämer, Ute

2017-02-01

Leaf mineral composition, the leaf ionome, reflects the complex interaction between a plant and its environment including local soil composition, an influential factor that can limit species distribution and plant productivity. Here we addressed within-species variation in plant-soil interactions and edaphic adaptation using Arabidopsis halleri, a well-suited model species as a facultative metallophyte and metal hyperaccumulator. We conducted multi-element analysis of 1972 paired leaf and soil samples from 165 European populations of A. halleri, at individual resolution to accommodate soil heterogeneity. Results were further confirmed under standardized conditions upon cultivation of 105 field-collected genotypes on an artificially metal-contaminated soil in growth chamber experiments. Soil-independent between- and within-population variation set apart leaf accumulation of zinc, cadmium and lead from all other nutrient and nonessential elements, concurring with differential hypothesized ecological roles in either biotic interaction or nutrition. For these metals, soil-leaf relationships were element-specific, differed between metalliferous and nonmetalliferous soils and were geographically structured both in the field and under standardized growth conditions, implicating complex scenarios of recent ecological adaptation. Our study provides an example and a reference for future related work and will serve as a basis for the molecular-genetic dissection and ecological analysis of the observed phenotypic variation. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

Combined Flux Chamber and Genomics Approach Links Nitrous Acid Emissions to Ammonia Oxidizing Bacteria and Archaea in Urban and Agricultural Soil.

PubMed

Scharko, Nicole K; Schütte, Ursel M E; Berke, Andrew E; Banina, Lauren; Peel, Hannah R; Donaldson, Melissa A; Hemmerich, Chris; White, Jeffrey R; Raff, Jonathan D

2015-12-01

Nitrous acid (HONO) is a photochemical source of hydroxyl radical and nitric oxide in the atmosphere that stems from abiotic and biogenic processes, including the activity of ammonia-oxidizing soil microbes. HONO fluxes were measured from agricultural and urban soil in mesocosm studies aimed at characterizing biogenic sources and linking them to indigenous microbial consortia. Fluxes of HONO from agricultural and urban soil were suppressed by addition of a nitrification inhibitor and enhanced by amendment with ammonium (NH4(+)), with peaks at 19 and 8 ng m(-2) s(-1), respectively. In addition, both agricultural and urban soils were observed to convert (15)NH4(+) to HO(15)NO. Genomic surveys of soil samples revealed that 1.5-6% of total expressed 16S rRNA sequences detected belonged to known ammonia oxidizing bacteria and archaea. Peak fluxes of HONO were directly related to the abundance of ammonia-oxidizer sequences, which in turn depended on soil pH. Peak HONO fluxes under fertilized conditions are comparable in magnitude to fluxes reported during field campaigns. The results suggest that biogenic HONO emissions will be important in soil environments that exhibit high nitrification rates (e.g., agricultural soil) although the widespread occurrence of ammonia oxidizers implies that biogenic HONO emissions are also possible in the urban and remote environment.

Bioremediation of petroleum-contaminated soil: A Review

NASA Astrophysics Data System (ADS)

Yuniati, M. D.

2018-02-01

Petroleum is the major source of energy for various industries and daily life. Releasing petroleum into the environment whether accidentally or due to human activities is a main cause of soil pollution. Soil contaminated with petroleum has a serious hazard to human health and causes environmental problems as well. Petroleum pollutants, mainly hydrocarbon, are classified as priority pollutants. The application of microorganisms or microbial processes to remove or degrade contaminants from soil is called bioremediation. This microbiological decontamination is claimed to be an efficient, economic and versatile alternative to physicochemical treatment. This article presents an overview about bioremediation of petroleum-contaminated soil. It also includes an explanation about the types of bioremediation technologies as well as the processes.

Microbiological and Geochemical Evidence of Fe(III) Reduction in the Rhizosphere (Root-Zone) of Wetland Plants

NASA Astrophysics Data System (ADS)

Weiss, J. V.; Megonigal, J. P.; Emerson, D.

2002-05-01

We have found that the Fe-oxide deposits (Fe-plaque) on wetland plant roots contain abundant microbes including Fe(II)-oxidizing bacteria (FeOB) (Appl. Environ. Microbiol. 1999, 65:2758-2761). In the current study, we investigated the potential for root Fe-plaque to serve as a substrate for Fe(III)-reducing bacteria (FeRB) and compared rates of Fe reduction between plaque and bulk soil. In a study at six wetland habitats located in the Mid-Atlantic region, abundances of FeRB in the rhizosphere of Typha spp. and the bulk soil were enumerated using the most probable number technique. In the rhizosphere, FeRB accounted for an average of 12% of the total cell number while in the soil they accounted for <1% of the total bacteria. We subsequently performed a sequential chemical extraction on both roots and soil to determine if FeRB abundances were driven by differences in the reducibility of Fe(III) in each environment. The roots contained a significantly higher percentage of amorphous Fe (77.4%; p<0.05 n=5 wetlands) than the bulk soil (33.8%); conversely, the soil also had significantly higher amounts of crystalline Fe (41.1%, p<0.05, n=5 wetlands) than the roots (8.1%). A significant correlation was observed between the percentage of amorphous Fe and the percentage of FeRB (r2=0.583; p<0.05). Since amorphous Fe is more readily reduced by microbes than crystalline Fe, these results suggested that the roots provide a good substrate for iron-reducing bacteria. To determine how differences in reducible Fe(III) might limit Fe reduction potential, we performed 12-day anaerobic incubations of roots and soil with Geobacter metallireducans, a common FeRB isolated from aquatic environments. Although Fe(III) reduction rates peaked at between 48 and 72 hours in both the roots and soils, the total amount of Fe(II) production in the root samples was significantly higher than that in the soil samples (350 μ moles g dry weight-1 vs. 153 μ moles g dry weight-1; p<0.05). All of these findings, including higher percentages of FeRB and amorphous Fe in the rhizosphere than in the bulk soil, support the hypothesis that the wetland plant rhizosphere is an active zone of Fe(III) reduction.

Including spatial data in nutrient balance modelling on dairy farms

NASA Astrophysics Data System (ADS)

van Leeuwen, Maricke; van Middelaar, Corina; Stoof, Cathelijne; Oenema, Jouke; Stoorvogel, Jetse; de Boer, Imke

2017-04-01

The Annual Nutrient Cycle Assessment (ANCA) calculates the nitrogen (N) and phosphorus (P) balance at a dairy farm, while taking into account the subsequent nutrient cycles of the herd, manure, soil and crop components. Since January 2016, Dutch dairy farmers are required to use ANCA in order to increase understanding of nutrient flows and to minimize nutrient losses to the environment. A nutrient balance calculates the difference between nutrient inputs and outputs. Nutrients enter the farm via purchased feed, fertilizers, deposition and fixation by legumes (nitrogen), and leave the farm via milk, livestock, manure, and roughages. A positive balance indicates to which extent N and/or P are lost to the environment via gaseous emissions (N), leaching, run-off and accumulation in soil. A negative balance indicates that N and/or P are depleted from soil. ANCA was designed to calculate average nutrient flows on farm level (for the herd, manure, soil and crop components). ANCA was not designed to perform calculations of nutrient flows at the field level, as it uses averaged nutrient inputs and outputs across all fields, and it does not include field specific soil characteristics. Land management decisions, however, such as the level of N and P application, are typically taken at the field level given the specific crop and soil characteristics. Therefore the information that ANCA provides is likely not sufficient to support farmers' decisions on land management to minimize nutrient losses to the environment. This is particularly a problem when land management and soils vary between fields. For an accurate estimate of nutrient flows in a given farming system that can be used to optimize land management, the spatial scale of nutrient inputs and outputs (and thus the effect of land management and soil variation) could be essential. Our aim was to determine the effect of the spatial scale of nutrient inputs and outputs on modelled nutrient flows and nutrient use efficiencies at Dutch dairy farms. We selected two dairy farms located on cover sands in the Netherlands. One farm was located on relatively homogeneous soil type, and one on many different soil types within the sandy soils. A full year of data of N and P inputs and outputs on farm and field level were provided by the farmers, including field level yields, yield composition, manure composition, degree of grazing and degree of mowing. Soil heterogeneity was defined as the number of soil units within the farm corrected for surface area, and quantified from the Dutch 1:50.000 soil map. N and P balances at farm and field level were determined, as well as differences in nutrient use efficiency, leaching, and N emission. We will present the effect of the spatial scale on nutrient balance analysis and discuss to which degree any differences are caused by within-farm land management and soil variation. This study highlights to which extent within-farm land management and soil variation should be taken into account when modelling nutrient flows and nutrient use efficiencies at farm level, to contribute to field-based decision making for improved land management.

Identification of traffic-related metals and the effects of different environments on their enrichment in roadside soils along the Qinghai-Tibet highway.

PubMed

Zhang, Hua; Wang, Zhaofeng; Zhang, Yili; Ding, Mingjun; Li, Lanhui

2015-07-15

The road transportation could affect roadside soils environment detrimentally, including heavy metal enrichment. In order to identify and evaluate the enrichment of heavy metals resulted from road transportation on the Tibetan Plateau, the 11 heavy metals (V, Cr, Co, Ni, Cu, Zn, As, Cd, Rb, Pb and Tl) in the topsoil (0-10 cm depth) from four sites along the Qinghai-Tibet highway were discussed in this study. Our results indicate that heavy metals such as Cr, Cu, Zn, As, Cd and Pb are related to road transportation. The content of most of these heavy metals in roadside soils decreased exponentially with the distance from the road, as did some of the Nemero Synthesis Indexes (PN values). The contamination factor for the traffic-related metals ranged from 0.56 (no pollution) to 5.67 (considerable pollution) and the Nemero Synthesis Indexes of these heavy metals ranged from 0.80 (no pollution) to 4.49 (severe pollution). Cd was of priority concern as it had the highest contamination factor. The highest PN value for these traffic-related heavy metals was found in soils at site TTH (alpine steppe). Although transportation contributed to the high contents of these traffic-related metals in roadside environments, regional differences such as wind and the terrain also had significant relationship with their enrichment in these roadside soils. The roadside distance at which there is a potential risk to livestock and wildlife from the contamination of soils by heavy metals should be determined scientifically along the Qinghai-Tibet highway, based on the different natural environments found in the region. Copyright © 2015 Elsevier B.V. All rights reserved.

Effects of soil and topographic factors on vegetation restoration in opencast coal mine dumps located in a loess area

NASA Astrophysics Data System (ADS)

Wang, Jinman; Wang, Hongdan; Cao, Yingui; Bai, Zhongke; Qin, Qian

2016-02-01

Vegetation plays an important role in improving and restoring fragile ecological environments. In the Antaibao opencast coal mine, located in a loess area, the eco-environment has been substantially disturbed by mining activities, and the relationship between the vegetation and environmental factors is not very clear. Therefore, it is crucial to understand the effects of soil and topographic factors on vegetation restoration to improve the fragile ecosystems of damaged land. An investigation of the soil, topography and vegetation in 50 reclamation sample plots in Shanxi Pingshuo Antaibao opencast coal mine dumps was performed. Statistical analyses in this study included one-way ANOVA and significance testing using SPSS 20.0, and multivariate techniques of detrended correspondence analysis (DCA) and redundancy analysis (RDA) using CANOCO 4.5. The RDA revealed the environmental factors that affected vegetation restoration. Various vegetation and soil variables were significantly correlated. The available K and rock content were good explanatory variables, and they were positively correlated with tree volume. The effects of the soil factors on vegetation restoration were higher than those of the topographic factors.

Effects of soil and topographic factors on vegetation restoration in opencast coal mine dumps located in a loess area

PubMed Central

Wang, Jinman; Wang, Hongdan; Cao, Yingui; Bai, Zhongke; Qin, Qian

2016-01-01

Vegetation plays an important role in improving and restoring fragile ecological environments. In the Antaibao opencast coal mine, located in a loess area, the eco-environment has been substantially disturbed by mining activities, and the relationship between the vegetation and environmental factors is not very clear. Therefore, it is crucial to understand the effects of soil and topographic factors on vegetation restoration to improve the fragile ecosystems of damaged land. An investigation of the soil, topography and vegetation in 50 reclamation sample plots in Shanxi Pingshuo Antaibao opencast coal mine dumps was performed. Statistical analyses in this study included one-way ANOVA and significance testing using SPSS 20.0, and multivariate techniques of detrended correspondence analysis (DCA) and redundancy analysis (RDA) using CANOCO 4.5. The RDA revealed the environmental factors that affected vegetation restoration. Various vegetation and soil variables were significantly correlated. The available K and rock content were good explanatory variables, and they were positively correlated with tree volume. The effects of the soil factors on vegetation restoration were higher than those of the topographic factors. PMID:26916152

Effects of soil and topographic factors on vegetation restoration in opencast coal mine dumps located in a loess area.

PubMed

Wang, Jinman; Wang, Hongdan; Cao, Yingui; Bai, Zhongke; Qin, Qian

2016-02-26

Vegetation plays an important role in improving and restoring fragile ecological environments. In the Antaibao opencast coal mine, located in a loess area, the eco-environment has been substantially disturbed by mining activities, and the relationship between the vegetation and environmental factors is not very clear. Therefore, it is crucial to understand the effects of soil and topographic factors on vegetation restoration to improve the fragile ecosystems of damaged land. An investigation of the soil, topography and vegetation in 50 reclamation sample plots in Shanxi Pingshuo Antaibao opencast coal mine dumps was performed. Statistical analyses in this study included one-way ANOVA and significance testing using SPSS 20.0, and multivariate techniques of detrended correspondence analysis (DCA) and redundancy analysis (RDA) using CANOCO 4.5. The RDA revealed the environmental factors that affected vegetation restoration. Various vegetation and soil variables were significantly correlated. The available K and rock content were good explanatory variables, and they were positively correlated with tree volume. The effects of the soil factors on vegetation restoration were higher than those of the topographic factors.

Spatial Distribution of Fungal Communities in an Arable Soil

PubMed Central

Moll, Julia; Hoppe, Björn; König, Stephan; Wubet, Tesfaye; Buscot, François; Krüger, Dirk

2016-01-01

Fungi are prominent drivers of ecological processes in soils, so that fungal communities across different soil ecosystems have been well investigated. However, for arable soils taxonomically resolved fine-scale studies including vertical itemization of fungal communities are still missing. Here, we combined a cloning/Sanger sequencing approach of the ITS/LSU region as marker for general fungi and of the partial SSU region for arbuscular mycorrhizal fungi (AMF) to characterize the microbiome in different maize soil habitats. Four compartments were analyzed over two annual cycles 2009 and 2010: a) ploughed soil in 0–10 cm, b) rooted soil in 40–50 cm, c) root-free soil in 60–70 cm soil depth and d) maize roots. Ascomycota was the most dominant phylum across all compartments. Fungal communities including yeasts and AMF differed strongly between compartments. Inter alia, Tetracladium, the overall largest MOTU (molecular operational taxonomic unit), occurred in all compartments, whereas Trichosporon dominated all soil compartments. Sequences belonging to unclassified Helotiales were forming the most abundant MOTUs exclusively present in roots. This study gives new insights on spatial distribution of fungi and helps to link fungal communities to specific ecological properties such as varying resources, which characterize particular niches of the heterogeneous soil environment. PMID:26840453

Quantification of spatial distribution and spread of bacteria in soil at microscale

NASA Astrophysics Data System (ADS)

Juyal, Archana; Eickhorst, Thilo; Falconer, Ruth; Baveye, Philippe; Otten, Wilfred

2015-04-01

Soil bacteria play an essential role in functioning of ecosystems and maintaining of biogeochemical cycles. Soil is a complex heterogeneous environment comprising of highly variable and dynamic micro-habitats that have significant impacts on the growth and activity of resident microbiota including bacteria and fungi. Bacteria occupy a very small portion of available pore space in soil which demonstrates that their spatial arrangement in soil has a huge impact on the contact to their target and on the way they interact to carry out their functions. Due to limitation of techniques, there is scant information on spatial distribution of indigenous or introduced bacteria at microhabitat scale. There is a need to understand the interaction between soil structure and microorganisms including fungi for ecosystem-level processes such as carbon sequestration and improving the predictive models for soil management. In this work, a combination of techniques was used including X-ray CT to characterize the soil structure and in-situ detection via fluorescence microscopy to visualize and quantify bacteria in soil thin sections. Pseudomonas fluorescens bacteria were introduced in sterilized soil of aggregate size 1-2 mm and packed at bulk-densities 1.3 g cm-3 and 1.5 g cm-3. A subset of samples was fixed with paraformaldehyde and subsequently impregnated with resin. DAPI and fluorescence in situ hybridization (FISH) were used to visualize bacteria in thin sections of soil cores by epifluorescence microscopy to enumerate spatial distribution of bacteria in soil. The pore geometry of soil was quantified after X-ray microtomography scanning. The distribution of bacteria introduced locally reduced significantly (P

Assessment of tomato and wine processing solid wastes as soil amendments for biosolarization.

PubMed

Achmon, Yigal; Harrold, Duff R; Claypool, Joshua T; Stapleton, James J; VanderGheynst, Jean S; Simmons, Christopher W

2016-02-01

Pomaces from tomato paste and wine production are the most abundant fruit processing residues in California. These residues were examined as soil amendments for solarization to promote conditions conducive to soil disinfestation (biosolarization). Simulated biosolarization studies were performed in both aerobic and anaerobic soil environments and soil temperature elevation, pH, and evolution of CO2, H2 and CH4 gases were measured as metrics of soil microbial activity. Tomato pomace amendment induced conditions associated with soil pest inactivation, including elevation of soil temperature by up to 2°C for a duration of 4days under aerobic conditions and a reduction of soil pH from 6.5 to 4.68 under anaerobic conditions. White wine grape pomace amendment showed similar trends but to a lesser extent. Red wine grape pomace was generally less suitable for biosolarization due to significantly lower soil temperature elevations, reduced acidification relative to the other pomaces and induction of methanogenesis in the soil. Copyright © 2015 Elsevier Ltd. All rights reserved.

The distribution of Listeria in pasture-raised broiler farm soils is potentially related to University of Vermont medium enrichment bias toward Listeria innocua over Listeria monocytogenes.

USDA-ARS?s Scientific Manuscript database

The occurrence of Listeria monocytogenes (LM) has been widely investigated in the poultry production chain from the processing plant to the final product. However, limited data are available on Listeria spp., including LM, in the poultry farm environment. Therefore, fecal and soil samples from 37 pa...

Biogeochemistry of vertebrate decomposition in a forest ecosystem

USDA-ARS?s Scientific Manuscript database

Decomposing plants and animals provide critical nutrients for ecosystems, including forests. During vertebrate decay, the rapid release of limiting nutrients, including N, P, C, and S fundamentally transforms the soil environment by stimulating endogenous organisms. The goal of this study was t...

Development of an extraction method for perchlorate in soils.

PubMed

Cañas, Jaclyn E; Patel, Rashila; Tian, Kang; Anderson, Todd A

2006-03-01

Perchlorate originates as a contaminant in the environment from its use in solid rocket fuels and munitions. The current US EPA methods for perchlorate determination via ion chromatography using conductivity detection do not include recommendations for the extraction of perchlorate from soil. This study evaluated and identified appropriate conditions for the extraction of perchlorate from clay loam, loamy sand, and sandy soils. Based on the results of this evaluation, soils should be extracted in a dry, ground (mortar and pestle) state with Milli-Q water in a 1 ratio 1 soil ratio water ratio and diluted no more than 5-fold before analysis. When sandy soils were extracted in this manner, the calculated method detection limit was 3.5 microg kg(-1). The findings of this study have aided in the establishment of a standardized extraction method for perchlorate in soil.

Automated image processing of Landsat II digital data for watershed runoff prediction

NASA Technical Reports Server (NTRS)

Sasso, R. R.; Jensen, J. R.; Estes, J. E.

1977-01-01

Digital image processing of Landsat data from a 230 sq km area was examined as a possible means of generating soil cover information for use in the watershed runoff prediction of Kern County, California. The soil cover information included data on brush, grass, pasture lands and forests. A classification accuracy of 94% for the Landsat-based soil cover survey suggested that the technique could be applied to the watershed runoff estimate. However, problems involving the survey of complex mountainous environments may require further attention

Diversity of Leptospira spp. in Rats and Environment from Urban Areas of Sarawak, Malaysia

PubMed Central

Pui, Chai Fung; Apun, Kasing; Su'ut, Lela

2017-01-01

Various prevalence studies on Leptospira in animals and humans, as well as environmental samples, had been conducted worldwide, including Malaysia. However, limited studies have been documented on the presence of pathogenic, intermediate, and saprophytic Leptospira in selected animals and environments. This study was therefore conducted to detect Leptospira spp. in rats, soil, and water from urban areas of Sarawak using the polymerase chain reaction (PCR) method. A total of 107 rats, 292 soil samples, and 324 water samples were collected from April 2014 to February 2015. Pathogenic Leptospira was present in 5.6% (6/107) of rats, 11.6% (34/292) of soil samples, and 1.9% (6/324) of water samples. Intermediate Leptospira was present in 2.7% (8/292) of soil samples and 1.9% (6/324) of water samples. Saprophytic Leptospira was present in 10.3% (11/107) of rats, 1.4% (4/292) of soil samples, and 0.3% (1/324) of water samples. From this study, 76 Leptospira spp. were isolated. Based on DNA sequencing, the dominant Leptospira spp. circulating in urban areas of Sarawak are pathogenic Leptospira noguchii, intermediate Leptospira wolffii serovar Khorat, and saprophytic Leptospira meyeri, respectively. Overall, this study provided important surveillance data on the prevalence of Leptospira spp. from rats and the environment, with dominant local serovars in urban areas of Sarawak. PMID:28348601

Diversity of Leptospira spp. in Rats and Environment from Urban Areas of Sarawak, Malaysia.

PubMed

Pui, Chai Fung; Bilung, Lesley Maurice; Apun, Kasing; Su'ut, Lela

2017-01-01

Various prevalence studies on Leptospira in animals and humans, as well as environmental samples, had been conducted worldwide, including Malaysia. However, limited studies have been documented on the presence of pathogenic, intermediate, and saprophytic Leptospira in selected animals and environments. This study was therefore conducted to detect Leptospira spp. in rats, soil, and water from urban areas of Sarawak using the polymerase chain reaction (PCR) method. A total of 107 rats, 292 soil samples, and 324 water samples were collected from April 2014 to February 2015. Pathogenic Leptospira was present in 5.6% (6/107) of rats, 11.6% (34/292) of soil samples, and 1.9% (6/324) of water samples. Intermediate Leptospira was present in 2.7% (8/292) of soil samples and 1.9% (6/324) of water samples. Saprophytic Leptospira was present in 10.3% (11/107) of rats, 1.4% (4/292) of soil samples, and 0.3% (1/324) of water samples. From this study, 76 Leptospira spp. were isolated. Based on DNA sequencing, the dominant Leptospira spp. circulating in urban areas of Sarawak are pathogenic Leptospira noguchii , intermediate Leptospira wolffii serovar Khorat, and saprophytic Leptospira meyeri , respectively. Overall, this study provided important surveillance data on the prevalence of Leptospira spp. from rats and the environment, with dominant local serovars in urban areas of Sarawak.

Current advancements and challenges in soil-root interactions modelling

NASA Astrophysics Data System (ADS)

Schnepf, Andrea; Huber, Katrin; Abesha, Betiglu; Meunier, Felicien; Leitner, Daniel; Roose, Tiina; Javaux, Mathieu; Vanderborght, Jan; Vereecken, Harry

2015-04-01

Roots change their surrounding soil chemically, physically and biologically. This includes changes in soil moisture and solute concentration, the exudation of organic substances into the rhizosphere, increased growth of soil microorganisms, or changes in soil structure. The fate of water and solutes in the root zone is highly determined by these root-soil interactions. Mathematical models of soil-root systems in combination with non-invasive techniques able to characterize root systems are a promising tool to understand and predict the behaviour of water and solutes in the root zone. With respect to different fields of applications, predictive mathematical models can contribute to the solution of optimal control problems in plant recourse efficiency. This may result in significant gains in productivity, efficiency and environmental sustainability in various land use activities. Major challenges include the coupling of model parameters of the relevant processes with the surrounding environment such as temperature, nutrient concentration or soil water content. A further challenge is the mathematical description of the different spatial and temporal scales involved. This includes in particular the branched structures formed by root systems or the external mycelium of mycorrhizal fungi. Here, reducing complexity as well as bridging between spatial scales is required. Furthermore, the combination of experimental and mathematical techniques may advance the field enormously. Here, the use of root system, soil and rhizosphere models is presented through a number of modelling case studies, including image based modelling of phosphate uptake by a root with hairs, model-based optimization of root architecture for phosphate uptake from soil, upscaling of rhizosphere models, modelling root growth in structured soil, and the effect of root hydraulic architecture on plant water uptake efficiency and drought resistance.

Current Advancements and Challenges in Soil-Root Interactions Modelling

NASA Astrophysics Data System (ADS)

Schnepf, A.; Huber, K.; Abesha, B.; Meunier, F.; Leitner, D.; Roose, T.; Javaux, M.; Vanderborght, J.; Vereecken, H.

2014-12-01

Roots change their surrounding soil chemically, physically and biologically. This includes changes in soil moisture and solute concentration, the exudation of organic substances into the rhizosphere, increased growth of soil microorganisms, or changes in soil structure. The fate of water and solutes in the root zone is highly determined by these root-soil interactions. Mathematical models of soil-root systems in combination with non-invasive techniques able to characterize root systems are a promising tool to understand and predict the behaviour of water and solutes in the root zone. With respect to different fields of applications, predictive mathematical models can contribute to the solution of optimal control problems in plant recourse efficiency. This may result in significant gains in productivity, efficiency and environmental sustainability in various land use activities. Major challenges include the coupling of model parameters of the relevant processes with the surrounding environment such as temperature, nutrient concentration or soil water content. A further challenge is the mathematical description of the different spatial and temporal scales involved. This includes in particular the branched structures formed by root systems or the external mycelium of mycorrhizal fungi. Here, reducing complexity as well as bridging between spatial scales is required. Furthermore, the combination of experimental and mathematical techniques may advance the field enormously. Here, the use of root system, soil and rhizosphere models is presented through a number of modelling case studies, including image based modelling of phosphate uptake by a root with hairs, model-based optimization of root architecture for phosphate uptake from soil, upscaling of rhizosphere models, modelling root growth in structured soil, and the effect of root hydraulic architecture on plant water uptake efficiency and drought resistance.

Manipulative experiments demonstrate how long-term soil moisture changes alter controls of plant water use

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

Grossiord, Charlotte; Sevanto, Sanna Annika; Limousin, Jean -Marc

Tree transpiration depends on biotic and abiotic factors that might change in the future, including precipitation and soil moisture status. Although short-term sap flux responses to soil moisture and evaporative demand have been the subject of attention before, the relative sensitivity of sap flux to these two factors under long-term changes in soil moisture conditions has rarely been determined experimentally. We tested how long-term artificial change in soil moisture affects the sensitivity of tree-level sap flux to daily atmospheric vapor pressure deficit ( VPD) and soil moisture variations, and the generality of these effects across forest types and environments usingmore » four manipulative sites in mature forests. Exposure to relatively long-term (two to six years) soil moisture reduction decreases tree sap flux sensitivity to daily VPD and relative extractable water ( REW) variations, leading to lower sap flux even under high soil moisture and optimal VPD. Inversely, trees subjected to long-term irrigation showed a significant increase in their sensitivity to daily VPD and REW, but only at the most water-limited site. The ratio between the relative change in soil moisture manipulation and the relative change in sap flux sensitivity to VPD and REW variations was similar across sites suggesting common adjustment mechanisms to long-term soil moisture status across environments for evergreen tree species. Altogether, our results show that long-term changes in soil water availability, and subsequent adjustments to these novel conditions, could play a critical and increasingly important role in controlling forest water use in the future.« less

Manipulative experiments demonstrate how long-term soil moisture changes alter controls of plant water use

DOE PAGES

Grossiord, Charlotte; Sevanto, Sanna Annika; Limousin, Jean -Marc; ...

2017-12-14

Tree transpiration depends on biotic and abiotic factors that might change in the future, including precipitation and soil moisture status. Although short-term sap flux responses to soil moisture and evaporative demand have been the subject of attention before, the relative sensitivity of sap flux to these two factors under long-term changes in soil moisture conditions has rarely been determined experimentally. We tested how long-term artificial change in soil moisture affects the sensitivity of tree-level sap flux to daily atmospheric vapor pressure deficit ( VPD) and soil moisture variations, and the generality of these effects across forest types and environments usingmore » four manipulative sites in mature forests. Exposure to relatively long-term (two to six years) soil moisture reduction decreases tree sap flux sensitivity to daily VPD and relative extractable water ( REW) variations, leading to lower sap flux even under high soil moisture and optimal VPD. Inversely, trees subjected to long-term irrigation showed a significant increase in their sensitivity to daily VPD and REW, but only at the most water-limited site. The ratio between the relative change in soil moisture manipulation and the relative change in sap flux sensitivity to VPD and REW variations was similar across sites suggesting common adjustment mechanisms to long-term soil moisture status across environments for evergreen tree species. Altogether, our results show that long-term changes in soil water availability, and subsequent adjustments to these novel conditions, could play a critical and increasingly important role in controlling forest water use in the future.« less

Archaeal dominated ammonia-oxidizing communities in Icelandic grassland soils are moderately affected by long-term N fertilization and geothermal heating

PubMed Central

Daebeler, Anne; Abell, Guy C. J.; Bodelier, Paul L. E.; Bodrossy, Levente; Frampton, Dion M. F.; Hefting, Mariet M.; Laanbroek, Hendrikus J.

2012-01-01

The contribution of ammonia-oxidizing bacteria and archaea (AOB and AOA, respectively) to the net oxidation of ammonia varies greatly between terrestrial environments. To better understand, predict and possibly manage terrestrial nitrogen turnover, we need to develop a conceptual understanding of ammonia oxidation as a function of environmental conditions including the ecophysiology of associated organisms. We examined the discrete and combined effects of mineral nitrogen deposition and geothermal heating on ammonia-oxidizing communities by sampling soils from a long-term fertilization site along a temperature gradient in Icelandic grasslands. Microarray, clone library and quantitative PCR analyses of the ammonia monooxygenase subunit A (amoA) gene accompanied by physico-chemical measurements of the soil properties were conducted. In contrast to most other terrestrial environments, the ammonia-oxidizing communities consisted almost exclusively of archaea. Their bacterial counterparts proved to be undetectable by quantitative polymerase chain reaction suggesting AOB are only of minor relevance for ammonia oxidation in these soils. Our results show that fertilization and local, geothermal warming affected detectable ammonia-oxidizing communities, but not soil chemistry: only a subset of the detected AOA phylotypes was present in higher temperature soils and AOA abundance was increased in the fertilized soils, while soil physio-chemical properties remained unchanged. Differences in distribution and structure of AOA communities were best explained by soil pH and clay content irrespective of temperature or fertilizer treatment in these grassland soils, suggesting that these factors have a greater potential for ecological niche-differentiation of AOA in soil than temperature and N fertilization. PMID:23060870

Archaeal dominated ammonia-oxidizing communities in Icelandic grassland soils are moderately affected by long-term N fertilization and geothermal heating.

PubMed

Daebeler, Anne; Abell, Guy C J; Bodelier, Paul L E; Bodrossy, Levente; Frampton, Dion M F; Hefting, Mariet M; Laanbroek, Hendrikus J

2012-01-01

The contribution of ammonia-oxidizing bacteria and archaea (AOB and AOA, respectively) to the net oxidation of ammonia varies greatly between terrestrial environments. To better understand, predict and possibly manage terrestrial nitrogen turnover, we need to develop a conceptual understanding of ammonia oxidation as a function of environmental conditions including the ecophysiology of associated organisms. We examined the discrete and combined effects of mineral nitrogen deposition and geothermal heating on ammonia-oxidizing communities by sampling soils from a long-term fertilization site along a temperature gradient in Icelandic grasslands. Microarray, clone library and quantitative PCR analyses of the ammonia monooxygenase subunit A (amoA) gene accompanied by physico-chemical measurements of the soil properties were conducted. In contrast to most other terrestrial environments, the ammonia-oxidizing communities consisted almost exclusively of archaea. Their bacterial counterparts proved to be undetectable by quantitative polymerase chain reaction suggesting AOB are only of minor relevance for ammonia oxidation in these soils. Our results show that fertilization and local, geothermal warming affected detectable ammonia-oxidizing communities, but not soil chemistry: only a subset of the detected AOA phylotypes was present in higher temperature soils and AOA abundance was increased in the fertilized soils, while soil physio-chemical properties remained unchanged. Differences in distribution and structure of AOA communities were best explained by soil pH and clay content irrespective of temperature or fertilizer treatment in these grassland soils, suggesting that these factors have a greater potential for ecological niche-differentiation of AOA in soil than temperature and N fertilization.

Manipulative experiments demonstrate how long-term soil moisture changes alter controls of plant water use

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

Grossiord, Charlotte; Sevanto, Sanna; Limousin, Jean-Marc

Tree transpiration depends on biotic and abiotic factors that might change in the future, including precipitation and soil moisture status. Although short-term sap flux responses to soil moisture and evaporative demand have been the subject of attention before, the relative sensitivity of sap flux to these two factors under long-term changes in soil moisture conditions has rarely been determined experimentally. We tested how long-term artificial change in soil moisture affects the sensitivity of tree-level sap flux to daily atmospheric vapor pressure deficit (VPD) and soil moisture variations, and the generality of these effects across forest types and environments using fourmore » manipulative sites in mature forests. Exposure to relatively long-term (two to six years) soil moisture reduction decreases tree sap flux sensitivity to daily VPD and relative extractable water (REW) variations, leading to lower sap flux even under high soil moisture and optimal VPD. Inversely, trees subjected to long-term irrigation showed a significant increase in their sensitivity to daily VPD and REW, but only at the most water-limited site. The ratio between the relative change in soil moisture manipulation and the relative change in sap flux sensitivity to VPD and REW variations was similar across sites suggesting common adjustment mechanisms to long-term soil moisture status across environments for evergreen tree species. Overall, our results show that long-term changes in soil water availability, and subsequent adjustments to these novel conditions, could play a critical and increasingly important role in controlling forest water use in the future.« less

Optimization of a sample processing protocol for recovery of Bacillus anthracis spores from soil

USGS Publications Warehouse

Silvestri, Erin E.; Feldhake, David; Griffin, Dale; Lisle, John T.; Nichols, Tonya L.; Shah, Sanjiv; Pemberton, A; Schaefer III, Frank W

2016-01-01

Following a release of Bacillus anthracis spores into the environment, there is a potential for lasting environmental contamination in soils. There is a need for detection protocols for B. anthracis in environmental matrices. However, identification of B. anthracis within a soil is a difficult task. Processing soil samples helps to remove debris, chemical components, and biological impurities that can interfere with microbiological detection. This study aimed to optimize a previously used indirect processing protocol, which included a series of washing and centrifugation steps. Optimization of the protocol included: identifying an ideal extraction diluent, variation in the number of wash steps, variation in the initial centrifugation speed, sonication and shaking mechanisms. The optimized protocol was demonstrated at two laboratories in order to evaluate the recovery of spores from loamy and sandy soils. The new protocol demonstrated an improved limit of detection for loamy and sandy soils over the non-optimized protocol with an approximate matrix limit of detection at 14 spores/g of soil. There were no significant differences overall between the two laboratories for either soil type, suggesting that the processing protocol will be robust enough to use at multiple laboratories while achieving comparable recoveries.

Effects of the chemical environment on the spectroscopic properties of clays: Applications for Mars

NASA Technical Reports Server (NTRS)

Bishop, Janice L.; Pieters, Carle M.

1992-01-01

Laboratory studies of Mars soil analogs pose unique problems, since soils interact readily with their environment and exhibit variable characteristics depending on the environment. We have performed a series of experiments focusing on the spectral properties of clays and how they vary as a function of composition and environment, including examination of fundamental as well as overtone absorptions, that occur in the mid- and near-IR, respectively. Smectite clays have been selected in our laboratory experiments as a primary surface analog for Mars because of their compatibility with results of the Viking biology experiments, their stability under current martian conditions, and their compatibility with reflectance spectra of Mars. We prepared a number of monoionic montmorillonites in order to examine the influence of cations on the water molecules in the clay interlayer region. Moessbauer spectra of several montmorillonites with variable amounts of interlayer iron confirm the presence of ferrihydrite.

Response of microbial community composition and function to soil climate change

USGS Publications Warehouse

Waldrop, M.P.; Firestone, M.K.

2006-01-01

Soil microbial communities mediate critical ecosystem carbon and nutrient cycles. How microbial communities will respond to changes in vegetation and climate, however, are not well understood. We reciprocally transplanted soil cores from under oak canopies and adjacent open grasslands in a California oak-grassland ecosystem to determine how microbial communities respond to changes in the soil environment and the potential consequences for the cycling of carbon. Every 3 months for up to 2 years, we monitored microbial community composition using phospholipid fatty acid analysis (PLFA), microbial biomass, respiration rates, microbial enzyme activities, and the activity of microbial groups by quantifying 13C uptake from a universal substrate (pyruvate) into PLFA biomarkers. Soil in the open grassland experienced higher maximum temperatures and lower soil water content than soil under the oak canopies. Soil microbial communities in soil under oak canopies were more sensitive to environmental change than those in adjacent soil from the open grassland. Oak canopy soil communities changed rapidly when cores were transplanted into the open grassland soil environment, but grassland soil communities did not change when transplanted into the oak canopy environment. Similarly, microbial biomass, enzyme activities, and microbial respiration decreased when microbial communities were transplanted from the oak canopy soils to the grassland environment, but not when the grassland communities were transplanted to the oak canopy environment. These data support the hypothesis that microbial community composition and function is altered when microbes are exposed to new extremes in environmental conditions; that is, environmental conditions outside of their "life history" envelopes. ?? 2006 Springer Science+Business Media, Inc.

40 CFR 158.33 - Confidential data.

Code of Federal Regulations, 2012 CFR

2012-07-01

... organism or the behavior of such pesticide in the environment, including, but not limited to, data on safety to fish and wildlife, humans and other mammals, plants, animals, and soil, and studies on...

40 CFR 158.33 - Confidential data.

Code of Federal Regulations, 2014 CFR

2014-07-01

... organism or the behavior of such pesticide in the environment, including, but not limited to, data on safety to fish and wildlife, humans and other mammals, plants, animals, and soil, and studies on...

A strategy for the survey of urban garden soils

NASA Astrophysics Data System (ADS)

Schwartz, C.; Chenot, E. D.; Cortet, J.; Douay, F.; Dumat, C.; Pernin, C.; Pourrut, B.

2012-04-01

In France and all over the world, there is no systematic data available on the quality (fertility and contamination) of garden soils. Nevertheless, there is a growing need for a typology and for a method dedicated to national and international garden soil survey. This inventory is much needed in the context of environmental risk assessment, to predict the potential impact on human health of the direct contact with garden soils and of the consumption of vegetables from gardens. The state of the art on the international knowledge on garden soils, gardening practices and food production, shows that gardens remain poorly known and very complex ecological, economical and social systems. Their global quality is the result of a wide number of factors including environment, history, specific characteristics of the gardens, gardeners and their practices, plant and/or animal productions and socio-economic context. The aim is then to better know the determinism of the agronomic, environmental and sanitary properties of gardens as a function of gardening practices and their impact on the quality of soils and plants. We propose a definition of "garden" and more generally of all the field "garden". The system "garden" is represented by attributes (soil and plant characteristics) and factors with various impacts (e.g. environment > soil parent material > former land uses > age and sex of gardener > gardening practices > socio-professional group > type and proportion of productions > climate > age of the garden > size of the garden > education, information > cultural origin > functions of the garden > regulations). A typology of gardens including 7 selected factors and associated categories and a method for describing, sampling and characterizing a population of gardens representative (for a country) are proposed. Based on the statistical analysis on regional databases, we have determined and proposed an optimum size for the collected population of garden soils. The discussion of the results highlights the main indicators of soil quality and the method for a survey of garden soils is proposed. These results and the resulting approach might be validated and used on a worldwide scale to collect garden soil samples with the objective of agronomic, environmental and sanitary studies adapted to this type of urban agriculture.

Selenium distribution in the Chinese environment and its relationship with human health: A review.

PubMed

Dinh, Quang Toan; Cui, Zewei; Huang, Jie; Tran, Thi Anh Thu; Wang, Dan; Yang, Wenxiao; Zhou, Fei; Wang, Mengke; Yu, Dasong; Liang, Dongli

2018-03-01

This paper reviewed the Se in the environment (including total Se in soil, water, plants, and food), the daily Se intake and Se content in human hair were also examined to elucidate Se distribution in the environment and its effects on human health in China. Approximately 51% of China is Se deficiency in soil, compared with 72% in the survey conducted in 1989. Low Se concentrations in soil, water, plants, human diet and thus human hair were found in most areas of China. The only significant difference was observed between Se-rich and Se-excessive areas for Se contents in water, staple cereal, vegetables, fruits, and animal-based food, no remarkable contrast was found among other areas (p>0.05). This study also demonstrated that 39-61% of Chinese residents have lower daily Se intakes according to WHO/FAO recommended value (26-34μg/day). Further studies should focus on thoroughly understanding the concentration, speciation, and distribution of Se in the environment and food chain to successfully utilize Se resources, remediate Se deficiency, and assess the Se states and eco-effects on human health. Copyright © 2017 Elsevier Ltd. All rights reserved.

Genetic by environment interactions affect plant–soil linkages

PubMed Central

Pregitzer, Clara C; Bailey, Joseph K; Schweitzer, Jennifer A

2013-01-01

The role of plant intraspecific variation in plant–soil linkages is poorly understood, especially in the context of natural environmental variation, but has important implications in evolutionary ecology. We utilized three 18- to 21-year-old common gardens across an elevational gradient, planted with replicates of five Populus angustifolia genotypes each, to address the hypothesis that tree genotype (G), environment (E), and G × E interactions would affect soil carbon and nitrogen dynamics beneath individual trees. We found that soil nitrogen and carbon varied by over 50% and 62%, respectively, across all common garden environments. We found that plant leaf litter (but not root) traits vary by genotype and environment while soil nutrient pools demonstrated genotype, environment, and sometimes G × E interactions, while process rates (net N mineralization and net nitrification) demonstrated G × E interactions. Plasticity in tree growth and litter chemistry was significantly related to the variation in soil nutrient pools and processes across environments, reflecting tight plant–soil linkages. These data overall suggest that plant genetic variation can have differential affects on carbon storage and nitrogen cycling, with implications for understanding the role of genetic variation in plant–soil feedback as well as management plans for conservation and restoration of forest habitats with a changing climate. PMID:23919173

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.

[Estimation on value of water and soil conservation of agricultural ecosystems in Xi' an metropolitan, Northwest China].

PubMed

Yang, Wen-yan; Zhou, Zhong-xue

2014-12-01

With the urban eco-environment increasingly deteriorating, the ecosystem services provided by modern urban agriculture are exceedingly significant to maintain and build more suitable environment in a city. Taking Xi' an metropolitan as the study area, based on remote sensing data, DEM data and the economic and social statistics data, the water and soil conservation service of the agricultural ecosystems was valued employing the remote sensing and geographic information system method, covering the reduction values on land waste, soil fertility loss and sediment loss from 2000 to 2011, and analyzed its changes in time and space. The results showed that during the study period, the total value of water and soil conservation service provided by agricultural systems in Xi' an metropolitan was increased by 46,086 and 33.008 billion yuan respectively from period of 2000 to 2005 and from 2005 to 2011. The cultivated land (including grains, vegetables and other farming land), forest (including orchard) and grassland provided higher value on the water and soil conservation service than waters and other land use. Ecosystem service value of water and soil conserva- tion provided by agriculture was gradually decreasing from the southern to the northern in Xi' an metropolitan. There were significantly positive relationship between the ecosystem service value and the vegetation coverage. Forest, orchard and grassland distributed intensively in the southern which had higher vegetation coverage than in northern where covered by more cultivated land, sparse forest and scattered orchard. There were significantly negative correlation between the urbanization level and the value of water and soil conservation. The higher level of urbanization, the lower value there was from built-up area to suburban and to countryside within Xi' an metropolitan.

Theoretical Relationships between Luminescence and Hillslope Soil Vertical Diffusivity: a Numerical Modeling Approach

NASA Astrophysics Data System (ADS)

Gray, H. J.; Tucker, G. E.; Mahan, S.

2017-12-01

Luminescence is a property of matter that can be used to obtain depositional ages from fine sand. Luminescence generates due to exposure to background ionizing radiation and is removed by sunlight exposure in a process known as bleaching. There is evidence to suggest that luminescence can also serve as a sediment tracer in fluvial and hillslope environments. For hillslope environments, it has been suggested that the magnitude of luminescence as a function of soil depth is related to the strength of soil mixing. Hillslope soils with a greater extent of mixing will have previously surficial sand grains moved to greater depths in a soil column. These previously surface-exposed grains will contain a lower luminescence than those which have never seen the surface. To attempt to connect luminescence profiles with soil mixing rate, here defined as the soil vertical diffusivity, I conduct numerical modelling of particles in hillslope soils coupled with equations describing the physics of luminescence. I use recently published equations describing the trajectories of particles under both exponential and uniform soil velocity soils profiles and modify them to include soil diffusivity. Results from the model demonstrates a strong connection between soil diffusivity and luminescence. Both the depth profiles of luminescence and the total percent of surface exposed grains will change drastically based on the magnitude of the diffusivity. This suggests that luminescence could potentially be used to infer the magnitude of soil diffusivity. However, I test other variables such as the soil production rate, e-folding length of soil velocity, background dose rate, and soil thickness, and I find these other variables can also affect the relationship between luminescence and diffusivity. This suggests that these other variables may need to be constrained prior to any inferences of soil diffusivity from luminescence measurements. Further field testing of the model in areas where the soil vertical diffusivity and other parameters are independently known will provide a test of this potential new method.

Adaptation of ammonia-oxidizing microorganisms to environment shift of paddy field soil.

PubMed

Ke, Xiubin; Lu, Yahai

2012-04-01

Adaptation of microorganisms to the environment is a central theme in microbial ecology. The objective of this study was to investigate the response of ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) to a soil medium shift. We employed two rice field soils collected from Beijing and Hangzhou, China. These soils contained distinct AOB communities dominated by Nitrosomonas in Beijing rice soil and Nitrosospira in Hangzhou rice soil. Three mixtures were generated by mixing equal quantities of Beijing soil and Hangzhou soil (BH), Beijing soil with sterilized Hangzhou soil (BSH), and Hangzhou soil with sterilized Beijing soil (HSB). Pure and mixed soils were permanently flooded, and the surface-layer soil where ammonia oxidation occurred was collected to determine the response of AOB and AOA to the soil medium shift. AOB populations increased during the incubation, and the rates were initially faster in Beijing soil than in Hangzhou soil. Nitrosospira (cluster 3a) and Nitrosomonas (communis cluster) increased with time in correspondence with ammonia oxidation in the Hangzhou and Beijing soils, respectively. The 'BH' mixture exhibited a shift from Nitrosomonas at day 0 to Nitrosospira at days 21 and 60 when ammonia oxidation became most active. In 'HSB' and 'BSH' mixtures, Nitrosospira showed greater stimulation than Nitrosomonas, both with and without N amendment. These results suggest that Nitrosospira spp. were better adapted to soil environment shifts than Nitrosomonas. Analysis of the AOA community revealed that the composition of AOA community was not responsive to the soil environment shifts or to nitrogen amendment. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Influence of contrast morphogenetic features of urban constructed soils on the functioning of Moscow green lawn urban ecosystems: analysis based on the field model experiment

NASA Astrophysics Data System (ADS)

Epikhina, Anna; Vizirskaya, Mariya; Mazirov, Ilya; Vasenev, Vyacheslav; Vasenev, Ivan; Valentini, Riccardo

2014-05-01

Green lawns are the key element of the urban environment. They occupy a considerable part of the city area and locate in different urban functional zones. Urban constructed soils under green lawns have a unique spatial variability in chemical and morphogenetic features. So far, there is lack of information on the influence of morphogenetic features of urban soils on the functioning of the green lawn ecosystems especially in Moscow - the biggest megalopolis in Europe. Urban lawns perform a number of principal functions including both aesthetic and environmental. The role of the green lawn ecosystems in global carbon cycle is one of their main environmental functions. It is traditionally assessed through carbon stocks and fluxes in the basic ecosystem components. So far, such a data for the urban lawn ecosystems of the Moscow megapolis is lacking. In addition to environmental functions, green lawns perform an important ornamental role, which is also a critical criterion of their optimal functioning. Considering the variability of driving factors, influencing green lawns in urban environment, we carry out the model experiment in order to analyze "pure" effect of soil morphogenetic features. The current study aimed to analyze the influence of contrast morphogenetic features of urban constructed soils on the environmental and aesthetic functions of lawn ecosystems in Moscow megapolis basing in the model experiment. We carry out the model experiment located at the experimental field of the Russian State Agrarian University. Special transparent containers developed for the experiment, provided an option to observe soil morphogenetic features dynamics, including the depth and material of the organic transformation. At the same soil body inside the containers was united with the outside environment through the system of holes in the bottom and walls. The set of urban constructed soils includ four contrast types of the top soil (turf (T), turf-sand (TSa), turf-soil (TSo) and sand-soil (SS)) with three version of the depths (5, 10 and 20 cm). Soil construction with 10 cm organic horizon from TS top soil was taken as a reference. Grass mixture used for the green lawn including: Lolium perenne, Poa pratensis and Festuca rubra. For all the containers we measured soil CO2 emission by Li-820, soil temperature and moisture and the grass ornamental quality based on the 30-score scale (Laptev; 1988). All the measurements have been done in June-October 2013 with two-week time steps. We also observed the dynamic in soil chemical features (Corg, Ntot and pHKCl) monthly. We found high seasonal dynamics for all the observed functioning parameters. The highest CO2 emission was obtained in the beginning of July, whereas the lowest one - at the end of August. Maximal averaged CO2 emission was shown for the TSa and TSo substrates with the 20 cm depth. The lowest flux has been fixed for the more mineralized substrat. Soil moisture was shown as the main driving factor influencing CO2 emission both for the seasonal dynamics and for the averaged values for different substrates and depths (r=0.5, p<0.05). As for the aesthetic function the highest grass ornamental quality was shown for 20 cm TS and 5 cm T substrate (30 scores), whereas the lowest one was obtained for SS substrate with 5 and 20 cm depths (5 scores). We also obtained high positive correlation between the grass ornamental quality and the CO2 emissions (r=0.84, p>0.05). This outcome highlights that the standards of urban constructed soils' optimal features should be the compromise between the beauty of the green lawn and climate mitigation demands. Supported by the RF governmental grant 11.G34.31.0079

Chemical equilibria model of strontium-90 adsorption and transport in soil in response to dynamic alkaline conditions.

PubMed

Spalding, B P; Spalding, I R

2001-01-15

Strontium-90 is a major hazardous contaminant of radioactive wastewater and its processing sludges at many Department of Energy (DOE) facilities. In the past, such contaminated wastewater and sludge have been disposed in soil seepage pits, lagoons, or cribs often under highly perturbed alkaline conditions (pH > 12) where 90Sr solubility is low and its adsorption to surrounding soil is high. As natural weathering returns these soils to near-neutral or slightly acidic conditions, the adsorbed and precipitated calcium and magnesium phases, in which 90Sr is carried, change significantly in both nature and amounts. No comprehensive computational method has been formulated previously to quantitatively simulate the dynamics of 90Sr in the soil-groundwater environment under such dynamic and wide-ranging conditions. A computational code, the Hydrologic Utility Model for Demonstrating Integrated Nuclear Geochemical Environmental Responses (HUMDINGER), was composed to describe the changing equilibria of 90Sr in soil based on its causative chemical reactions including soil buffering, pH-dependent cation-exchange capacity, cation selectivity, and the precipitation/dissolution of calcium carbonate, calcium hydroxide, and magnesium hydroxide in response to leaching groundwater characteristics including pH, acid-neutralizing capacity, dissolved cations, and inorganic carbonate species. The code includes a simulation of one-dimensional transport of 90Sr through a soil column as a series of soil mixing cells where the equilibrium soluble output from one cell is applied to the next cell. Unamended soil leaching and highly alkaline soil treatments, including potassium hydroxide, sodium silicate, and sodium aluminate, were simulated and compared with experimental findings using large (10 kg) soil columns that were leached with 90Sr-contaminated groundwater after treatment. HUMDINGER's simulations were in good agreement with dynamic experimental observations of soil exchange capacity, exchangeable cations, total 90Sr, and pH values of layers within the soil columns and of column effluents.

Relative influence of wildfire on soil properties and erosion processes in different Mediterranean environments in NE Spain.

PubMed

Pardini, Giovanni; Gispert, Maria; Dunjó, Gemma

2004-07-26

Abandonment of terraced soils and increased brushland cover has increased wildfire occurrence to almost an annual rate in the Cap de Creus Peninsula, NE Pyrenees Range, Province of Girona, Spain. A wildfire occurred in August 2000 and affected an area of 6760 ha of shrubs and cork trees, whereas still cultivated plots were only slightly affected. Five stations of erosion measurements, corresponding to five different environments (from present cultivation to late abandonment) were destroyed by the passage of fire, and were promptly replaced to allow to monitoring post-fire effects on soil erosion. Selected soil properties were determined monthly before the fire and during 6 months after the fire at a monthly rate. Runoff and sediment yield together with dissolved organic carbon (DOC) in runoff water and organic carbon losses in eroded sediments (EOC) were evaluated throughout 2000. The last stage of abandonment, stands of cork trees, had the highest soil stability. Nevertheless, evidence of unfavourable soil conditions was detected at the shrub stage, when Cistus monspeliensis cover was the dominant opportunistic plant. This stage was considered to be a critical threshold leading either to degradation or regeneration processes according to fire frequency. A drastic change in soil properties, erosion and nutrient depletion occurred after the fire in all the environments. Statistics enabled to state that environments differed significantly in main soil properties. By statistically comparing the measured variables between the environments before and after the fire, DOC was found to be the soil parameter showing the highest significance between environments. Absolute values of erosion were low with respect to other Mediterranean environments although the shallow nature of these soils might deserve special attention because of a comparatively higher risk of degradation. Copyright 2004 Elsevier B.V.

Phosphorus nutrition of phosphorus-sensitive Australian native plants: threats to plant communities in a global biodiversity hotspot

PubMed Central

Lambers, Hans; Ahmedi, Idriss; Berkowitz, Oliver; Dunne, Chris; Finnegan, Patrick M.; Hardy, Giles E. St J.; Jost, Ricarda; Laliberté, Etienne; Pearse, Stuart J.; Teste, François P.

2013-01-01

South-western Australia harbours a global biodiversity hotspot on the world's most phosphorus (P)-impoverished soils. The greatest biodiversity occurs on the most severely nutrient-impoverished soils, where non-mycorrhizal species are a prominent component of the flora. Mycorrhizal species dominate where soils contain slightly more phosphorus. In addition to habitat loss and dryland salinity, a major threat to plant biodiversity in this region is eutrophication due to enrichment with P. Many plant species in the south-western Australian biodiversity hotspot are extremely sensitive to P, due to a low capability to down-regulate their phosphate-uptake capacity. Species from the most P-impoverished soils are also very poor competitors at higher P availability, giving way to more competitive species when soil P concentrations are increased. Sources of increased soil P concentrations include increased fire frequency, run-off from agricultural land, and urban activities. Another P source is the P-fertilizing effect of spraying natural environments on a landscape scale with phosphite to reduce the impacts of the introduced plant pathogen Phytophthora cinnamomi, which itself is a serious threat to biodiversity. We argue that alternatives to phosphite for P. cinnamomi management are needed urgently, and propose a strategy to work towards such alternatives, based on a sound understanding of the physiological and molecular mechanisms of the action of phosphite in plants that are susceptible to P. cinnamomi. The threats we describe for the south-western Australian biodiversity hotspot are likely to be very similar for other P-impoverished environments, including the fynbos in South Africa and the cerrado in Brazil. PMID:27293594

Potentially toxic elements in soil of the Khyber Pakhtunkhwa province and Tribal areas, Pakistan: evaluation for human and ecological risk assessment.

PubMed

Saddique, Umar; Muhammad, Said; Tariq, Mohsin; Zhang, Hua; Arif, Mohammad; Jadoon, Ishtiaq A K; Khattak, Nimat Ullah

2018-03-22

Potentially toxic elements (PTEs) contaminations in the soil ecosystem are considered as extremely hazardous due to toxicity, persistence and bioaccumulative nature. Therefore, this study was aimed to summarize the results of published PTEs in soil of Khyber Pakhtunkhwa and Tribal areas, Pakistan. Results were evaluated for the pollution quantification factors, including contamination factor (CF), pollution load index (PLI), ecological risk index (ERI) and human health risk assessment. The highest CF (797) and PLI (7.35) values were observed for Fe and ERI (857) values for Cd. Soil PTEs concentrations were used to calculate the human exposure for the risk assessment, including chronic or non-carcinogenic risks such as the hazard quotient (HQ) and carcinogenic or cancer risk (CR). The values of HQ were > 1 for the Cd, Co and Cr in Khyber Pakhtunkhwa and Tribal areas. Tribal areas showed higher values of ERI, HQ, and CR as compared to the Khyber Pakhtunkhwa that were attributed to the mining activities, weathering and erosion of mafic and ultramafic bedrocks hosting ophiolites. This study strongly recommends that best control measures need to be taken for soil PTEs with the intent to alleviate any continuing potential threat to the human health, property and environment, which otherwise could enter ecosystem and ultimately the living beings. Further studies are recommended to combat the soil PTEs concentrations and toxicity in the Tribal areas for a best picture of understanding the element effects on human, and environment can be achieved that will lead to a sustainable ecological harmony.

Phosphorus nutrition of phosphorus-sensitive Australian native plants: threats to plant communities in a global biodiversity hotspot.

PubMed

Lambers, Hans; Ahmedi, Idriss; Berkowitz, Oliver; Dunne, Chris; Finnegan, Patrick M; Hardy, Giles E St J; Jost, Ricarda; Laliberté, Etienne; Pearse, Stuart J; Teste, François P

2013-01-01

South-western Australia harbours a global biodiversity hotspot on the world's most phosphorus (P)-impoverished soils. The greatest biodiversity occurs on the most severely nutrient-impoverished soils, where non-mycorrhizal species are a prominent component of the flora. Mycorrhizal species dominate where soils contain slightly more phosphorus. In addition to habitat loss and dryland salinity, a major threat to plant biodiversity in this region is eutrophication due to enrichment with P. Many plant species in the south-western Australian biodiversity hotspot are extremely sensitive to P, due to a low capability to down-regulate their phosphate-uptake capacity. Species from the most P-impoverished soils are also very poor competitors at higher P availability, giving way to more competitive species when soil P concentrations are increased. Sources of increased soil P concentrations include increased fire frequency, run-off from agricultural land, and urban activities. Another P source is the P-fertilizing effect of spraying natural environments on a landscape scale with phosphite to reduce the impacts of the introduced plant pathogen Phytophthora cinnamomi, which itself is a serious threat to biodiversity. We argue that alternatives to phosphite for P. cinnamomi management are needed urgently, and propose a strategy to work towards such alternatives, based on a sound understanding of the physiological and molecular mechanisms of the action of phosphite in plants that are susceptible to P. cinnamomi. The threats we describe for the south-western Australian biodiversity hotspot are likely to be very similar for other P-impoverished environments, including the fynbos in South Africa and the cerrado in Brazil.

PFAM 2.0 - Documentations

EPA Pesticide Factsheets

The advanced capabilities of PFAM include accounting for water and pest management practices and for degradation in soil and aquatic environments, as well as for post processing of discharged paddy waters to a user-defined receiving water.

Clay mineral type effect on bacterial enteropathogen survival in soil.

PubMed

Brennan, Fiona P; Moynihan, Emma; Griffiths, Bryan S; Hillier, Stephen; Owen, Jason; Pendlowski, Helen; Avery, Lisa M

2014-01-15

Enteropathogens released into the environment can represent a serious risk to public health. Soil clay content has long been known to have an important effect on enteropathogen survival in soil, generally enhancing survival. However, clay mineral composition in soils varies, and different clay minerals have specific physiochemical properties that would be expected to impact differentially on survival. This work investigated the effect of clay materials, with a predominance of a particular mineral type (montmorillonite, kaolinite, or illite), on the survival in soil microcosms over 96 days of Listeria monocytogenes, Salmonella Dublin, and Escherichia coli O157. Clay mineral addition was found to alter a number of physicochemical parameters in soil, including cation exchange capacity and surface area, and this was specific to the mineral type. Clay mineral addition enhanced enteropathogen survival in soil. The type of clay mineral was found to differentially affect enteropathogen survival and the effect was enteropathogen-specific. © 2013.

In vitro experimental environments lacking or containing soil disparately affect competition experiments of Aspergillus flavus and co-occurring fungi in maize grains.

PubMed

Falade, Titilayo D O; Syed Mohdhamdan, Sharifah H; Sultanbawa, Yasmina; Fletcher, Mary T; Harvey, Jagger J W; Chaliha, Mridusmita; Fox, Glen P

2016-07-01

In vitro experimental environments are used to study interactions between microorganisms, and to predict dynamics in natural ecosystems. This study highlights that experimental in vitro environments should be selected to match closely the natural environment of interest during in vitro studies to strengthen extrapolations about aflatoxin production by Aspergillus and competing organisms. Fungal competition and aflatoxin accumulation were studied in soil, cotton wool or tube (water-only) environments, for Aspergillus flavus competition with Penicillium purpurogenum, Fusarium oxysporum or Sarocladium zeae within maize grains. Inoculated grains were incubated in each environment at two temperature regimes (25 and 30°C). Competition experiments showed interaction between the main effects of aflatoxin accumulation and the environment at 25°C, but not so at 30°C. However, competition experiments showed fungal populations were always interacting with their environments. Fungal survival differed after the 72-h incubation in different experimental environments. Whereas all fungi incubated within the soil environment survived, in the cotton wool environment none of the competitors of A. flavus survived at 30°C. With aflatoxin accumulation, F. oxysporum was the only fungus able to interdict aflatoxin production at both temperatures. This occurred only in the soil environment and fumonisins accumulated instead. Smallholder farmers in developing countries face serious mycotoxin contamination of their grains, and soil is a natural reservoir for the associated fungal propagules, and a drying and storage surface for grains on these farms. Studying fungal dynamics in the soil environment and other environments in vitro can provide insights into aflatoxin accumulation post-harvest.

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...

Similar soil microbial community structure across different environments after long-term succession: evidence from volcanoes of different ages.

PubMed

Xu, Shangqi; Zhang, Jianfeng; Luo, Shasha; Zhou, Xue; Shi, Shaohua; Tian, Chunjie

2018-06-08

Soil microbes play critical roles in global biogeochemical cycles, but their succession patterns across long temporal scales have rarely been studied. In this study, soil samples were collected from three volcanoes in Wudalianchi, northeastern China: Laoheishan (LH, approximately 240 years old), Dongjiaodebushan (DJ, 0.45-0.6 million years old), and Nangelaqiushan (NG, 0.8-1.3 million years old). For each volcano, both southern (S) and northern (N) slope aspects were sampled. Soil microbial communities were analyzed using phospholipid fatty acid analysis (PLFA). The results showed that soil properties and microbial biomass changed perceptibly among different volcanoes and different slope aspects. Almost all of the detected soil nutrient contents of LH were lowest, and total microbial biomass of LH was 40 and 36% lower than those of NG and DJ, respectively. LH was significantly different from NG and DJ in soil microbial community structure with a higher relative abundance of fungi and a lower relative abundance of actinomycetes and bacteria. However, for the two ancient volcanoes (NG and DJ), soil microbial community structures were highly similar among different ages and different slope aspects. No difference was detected in any of the measured microbial indices, including richness, evenness, Shannon's diversity, Simpson's diversity and the relative abundance of different microbial groups. The results indicated that while soil microbial biomass may change across different soil environments after long-term succession, soil microbial community structure can remain relatively stable. The results further indicated that soil microbes may show different successional patterns in different stages of succession. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Review of progress in soil inorganic carbon research

NASA Astrophysics Data System (ADS)

Bai, S. G.; Jiao, Y.; Yang, W. Z.; Gu, P.; Yang, J.; Liu, L. J.

2017-12-01

Soil inorganic carbon is one of the main carbon banks in the near-surface environment, and is the main form of soil carbon library in arid and semi-arid regions, which plays an important role in the global carbon cycle. This paper mainly focuses on the inorganic dynamic process of soil inorganic carbon in soil environment in arid and semi-arid regions, and summarized the composition and source of soil inorganic carbon, influence factors and soil carbon sequestration.

Landscape Disturbance History and Belowground Carbon Dynamics.

NASA Astrophysics Data System (ADS)

Marin-Spiotta, E.; Smith, A. P.; Atkinson, E. E.; Chaopricha, N. T.

2014-12-01

Earth system models vary in their predictions of carbon (C) uptake and release by the terrestrial biosphere, partly due to great uncertainties in the response of soils, one of the largest C reservoirs. The world's soils play a major role in the exchange of greenhouse gases with the atmosphere, in sustaining primary production, and in providing food security. Despite this, the sensitivity of soils to disturbance is highly uncertain. One reason for this is geographic variability in the importance of different mechanisms regulating soil C turnover. Most of our understanding of factors influencing soil organic C dynamics comes from research in temperate soils, despite the major role of tropical soils in the global C cycle. Even in the tropics, the diversity of soil environments is grossly underrepresented in the literature. This has important implications for predictions of soil C change across latitudes. We discuss results from the response of soil C pools and microbial communities to land use legacies on two contrasting tropical soil environments. Uncertainties in the response of soil C to disturbance also stem from a historic focus on shallow depths and the assumption that deep soil C is unreactive to landscape change. Growing evidence indicates that soil C pools in deep mineral horizons can be sensitive to changes in land cover and climate. This realization highlights the need to reassess the source of soil C at depth and the processes contributing to its stabilization. We discuss results from the interaction between multiple disturbances: drought, fire and erosion, on the accumulation of soil C at depths beyond those typically included in regional or global inventories. Our data show that deep soil C can be reactive and be a potential source of C if reconnected to the atmosphere. A deeper, mechanistic appreciation for a landscape's history of disturbance is critical for predicting feedbacks between the terrestrial biosphere and the climate system.

Arctic mosses govern below-ground environment and ecosystem processes.

PubMed

Gornall, J L; Jónsdóttir, I S; Woodin, S J; Van der Wal, R

2007-10-01

Mosses dominate many northern ecosystems and their presence is integral to soil thermal and hydrological regimes which, in turn, dictate important ecological processes. Drivers, such as climate change and increasing herbivore pressure, affect the moss layer thus, assessment of the functional role of mosses in determining soil characteristics is essential. Field manipulations conducted in high arctic Spitsbergen (78 degrees N), creating shallow (3 cm), intermediate (6 cm) and deep (12 cm) moss layers over the soil surface, had an immediate impact on soil temperature in terms of both average temperatures and amplitude of fluctuations. In soil under deep moss, temperature was substantially lower and organic layer thaw occurred 4 weeks later than in other treatment plots; the growing season for vascular plants was thereby reduced by 40%. Soil moisture was also reduced under deep moss, reflecting the influence of local heterogeneity in moss depth, over and above the landscape-scale topographic control of soil moisture. Data from field and laboratory experiments show that moss-mediated effects on the soil environment influenced microbial biomass and activity, resulting in warmer and wetter soil under thinner moss layers containing more plant-available nitrogen. In arctic ecosystems, which are limited by soil temperature, growing season length and nutrient availability, spatial and temporal variation in the depth of the moss layer has significant repercussions for ecosystem function. Evidence from our mesic tundra site shows that any disturbance causing reduction in the depth of the moss layer will alleviate temperature and moisture constraints and therefore profoundly influence a wide range of ecosystem processes, including nutrient cycling and energy transfer.

A comprehensive guide of remediation technologies for oil contaminated soil - Present works and future directions.

PubMed

Lim, Mee Wei; Lau, Ee Von; Poh, Phaik Eong

2016-08-15

Oil spills result in negative impacts on the environment, economy and society. Due to tidal and waves actions, the oil spillage affects the shorelines by adhering to the soil, making it difficult for immediate cleaning of the soil. As shoreline clean-up is the most costly component of a response operation, there is a need for effective oil remediation technologies. This paper provides a review on the remediation technologies for soil contaminated with various types of oil, including diesel, crude oil, petroleum, lubricating oil, bitumen and bunker oil. The methods discussed include solvent extraction, bioremediation, phytoremediation, chemical oxidation, electrokinetic remediation, thermal technologies, ultrasonication, flotation and integrated remediation technologies. Each of these technologies was discussed, and associated with their advantages, disadvantages, advancements and future work in detail. Nonetheless, it is important to note that no single remediation technology is considered the best solution for the remediation of oil contaminated soil. This review provides a comprehensive literature on the various remediation technologies studied in the removal of different oil types from soil. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Interrelationships between soil fauna and soil environmental factors in China: research advance].

PubMed

Wang, Yi; Wei, Wei; Yang, Xing-zhong; Chen, Li-ding; Yang, Lei

2010-09-01

Soil fauna has close relations with various environmental factors in soil ecosystem. To explore the interrelationships between soil fauna and soil environmental factors is of vital importance to deep understand the dynamics of soil ecosystem and to assess the functioning of the ecosystem. The environmental factors affecting soil fauna can be classified as soil properties and soil external environment. The former contains soil basic physical and chemical properties, soil moisture, and soil pollution. The latter includes vegetation, land use type, landform, and climate, etc. From these aspects, this paper summarized the published literatures in China on the interrelationships between soil fauna and soil environmental factors. It was considered that several problems were existed in related studies, e.g., fewer researches were made in integrating soil fauna's bio-indicator function, research methods were needed to be improved, and the studies on the multi-environmental factors and their large scale spatial-temporal variability were in deficiency. Corresponding suggestions were proposed, i.e., more work should be done according to the practical needs, advanced experiences from abroad should be referenced, and comprehensive studies on multi-environmental factors and long-term monitoring should be conducted on large scale areas.

Geochemical cartography as a tool for assessing the degree of soil contamination with heavy metals in Poland

NASA Astrophysics Data System (ADS)

Szymon Borkowski, Andrzej; Kwiatkowska-Malina, Jolanta

2016-04-01

Spatial disposition of chemical elements including heavy metals in the soil environment is a very important information during preparation of the thematic maps for the environmental protection and/or spatial planning. This knowledge is also essential for the earth's surface and soil's monitoring, designation of areas requiring improvement including remediation. The main source of anthropogenic pollution of soil with heavy metals are industry related to the mining coal and liquid fuels, mining and metallurgy, chemical industry, energy production, waste management, agriculture and transport. The geochemical maps as a kind of specific thematic maps made on the basis of datasets obtained from the Polish Geological Institute's resources allow to get to know the spatial distribution of different chemical elements including heavy metals in soil. The results of the research carried out by the Polish Geological Institute showed strong contamination in some regions in Poland mainly with arsenic, cadmium, lead and nickel. For this reason it was the point to prepare geochemical maps showing contamination of soil with heavy metals, and determine main sources of contamination and zones where heavy metals concentration was higher than acceptable contents. It was also presented a summary map of soil contamination with heavy metals. Additionally, location of highly contaminated zones was compiled with predominant in those areas types of arable soils and then results were thoroughly analyzed. This information can provide a base for further detailed studies on the soil contamination with heavy metals.

Fractionation and analysis of veterinary antibiotics and their related degradation products in agricultural soils and drainage waters following swine manure amendment.

PubMed

Solliec, Morgan; Roy-Lachapelle, Audrey; Gasser, Marc-Olivier; Coté, Caroline; Généreux, Mylène; Sauvé, Sébastien

2016-02-01

The fate of antimicrobial active compound residues in the environment, and especially antibiotics used in swine husbandry are of particular interest for their potential toxicity and contribution to antibiotic resistance. The presence of relatively high concentrations of bioactive compounds has been reported in agricultural areas but few information is available on their degradation products. Veterinary antibiotics reach terrestrial environments through many routes, including application of swine manure to soils. The objectives of this project were first, to develop an analytical method able to quantify and identify veterinary antibiotics and their degradation products in manure, soil and water samples; and second, to study the distribution of these target compounds in soils and drainage waters. A brief evaluation of their potential toxicity in the environment was also made. In order to achieve these objectives, liquid chromatography coupled to high-resolution mass spectrometry was used for its ability to quantify contaminants with sensitivity and selectivity, and its capacity to identify degradation products. Samples of manure, soil and water came from a long-term experimental site where swine manure containing veterinary antibiotics has been applied for many years. In this study, tetracycline antibiotics were found at several hundred μg L(-1) in the swine manure slurry used for fertilization, several hundred of ng L(-1) in drainage waters and several ng g(-1) in soils, while degradation products were sometimes found at concentrations higher than the parent compounds. Copyright © 2015 Elsevier B.V. All rights reserved.

Methanogenic archaea are globally ubiquitous in aerated soils and become active under wet anoxic conditions

PubMed Central

Angel, Roey; Claus, Peter; Conrad, Ralf

2012-01-01

The prototypical representatives of the Euryarchaeota—the methanogens—are oxygen sensitive and are thought to occur only in highly reduced, anoxic environments. However, we found methanogens of the genera Methanosarcina and Methanocella to be present in many types of upland soils (including dryland soils) sampled globally. These methanogens could be readily activated by incubating the soils as slurry under anoxic conditions, as seen by rapid methane production within a few weeks, without any additional carbon source. Analysis of the archaeal 16S ribosomal RNA gene community profile in the incubated samples through terminal restriction fragment length polymorphism and quantification through quantitative PCR indicated dominance of Methanosarcina, whose gene copy numbers also correlated with methane production rates. Analysis of the δ13C of the methane further supported this, as the dominant methanogenic pathway was in most cases aceticlastic, which Methanocella cannot perform. Sequences of the key methanogenic enzyme methyl coenzyme M reductase retrieved from the soil samples before incubation confirmed that Methanosarcina and Methanocella are the dominant methanogens, though some sequences of Methanobrevibacter and Methanobacterium were also detected. The global occurrence of only two active methanogenic archaea supports the hypothesis that these are autochthonous members of the upland soil biome and are well adapted to their environment. PMID:22071343

Prairies Water Management on Corps Lands

DTIC Science & Technology

2009-02-01

less influence (Whisenant 1999). The soil organic matter content reaches equilibrium between humus formation (favored by high inputs of residues...and humus loss (favored by moist soil and high temperatures). Waterlogged soils with anaerobic conditions have a slow decomposition rate that...wet environment, soils tend to have low humus content, while in a cold environment soils have higher humus content. This equilibrium remains

Dissipation and enantioselective degradation of plant growth retardants paclobutrazol and uniconazole in open field, greenhouse, and laboratory soils.

PubMed

Wu, Chengwang; Sun, Jianqiang; Zhang, Anping; Liu, Weiping

2013-01-15

Greenhouses are increasingly important in human food supply. Pesticides used in greenhouses play important roles in horticulture; however, little is known about their behavior in greenhouse environments. This work investigates the dissipation and enantioselctive degradation of plant growth retardants including paclobutrazol and uniconazole in soils under three conditions (i.e., open field, greenhouse, and laboratory). The dissipation and enantioselective degradation of paclobutrazol and uniconazole in greenhouse were different from those in open field; they were more persistent in greenhouse than in open field soil. Leaching produced by rainfall is responsible for the difference in dissipation. Thus, local environmental impacts may occur more easily inside greenhouses, while groundwater may be more contaminated in open field. Spike concentrations of 5, 10, and 20 times the concentrations of native residues were tested for the enantioselective dissipation of the two pesticides; the most potent enantioselective degradation of paclobutrazol and uniconazole occurred at the 10 times that of the native residues in the greenhouse environments and at 20 times native residues in open field environments. The higher soil activity in greenhouses than in open fields was thought to be responsible for such a difference. The environmental risk and regulation of paclobutrazol and uniconazole should be considered at the enantiomeric level.

Variations in the Fe mineralogy of bright Martian soil

NASA Technical Reports Server (NTRS)

Murchie, Scott; Mustard, John; Erard, Stephane; Geissler, Paul; Singer, Robert

1993-01-01

Bright regions on Mars are interpreted as 'soil' derived by chemical alteration of crustal rocks, whose main pigmentary component is ferric oxide or oxyhydroxide. The mineralogy and mineralogic variability of ferric iron are important evidence for the evolution of Martian soil: mineralogy of ferric phases is sensitive to chemical conditions in their genetic environments, and the spatial distributions of different ferric phases would record a history of both chemical environments and physical mixing. Reflectance spectroscopic studies provide several types of evidence that discriminate possible pigmentary phases, including the position of a crystal field absorption near 0.9 microns and position and strengths of absorptions in the UV-visible wavelength region. Recent telescopic spectra and laboratory measurements of Mars soil analogs suggest that spectral features of bright soil can be explained based on a single pigmentary phase, hematite (alpha-Fe2O3), occurring in both 'nanophase' and more crystalline forms. Here we report on a systematic investigation of Martian bright regions using ISM imaging spectrometer data, in which we examined spatial variations in the position and shape of the approximately 0.9 microns absorption. We found both local and regional heterogeneities that indicate differences in Fe mineralogy. These results demonstrate that bright soils do not represent a single lithology that has been homogenized by eolian mixing, and suggest that weathering of soils in different geologic settings has followed different physical and chemical pathways.

Methanogens at the top of the world: occurrence and potential activity of methanogens in newly deglaciated soils in high-altitude cold deserts in the Western Himalayas

PubMed Central

Aschenbach, Katrin; Conrad, Ralf; Řeháková, Klára; Doležal, Jiří; Janatková, Kateřina; Angel, Roey

2013-01-01

Methanogens typically occur in reduced anoxic environments. However, in recent studies it has been shown that many aerated upland soils, including desert soils also host active methanogens. Here we show that soil samples from high-altitude cold deserts in the western Himalayas (Ladakh, India) produce CH4 after incubation as slurry under anoxic conditions at rates comparable to those of hot desert soils. Samples of matured soil from three different vegetation belts (arid, steppe, and subnival) were compared with younger soils originating from frontal and lateral moraines of receding glaciers. While methanogenic rates were higher in the samples from matured soils, CH4 was also produced in the samples from the recently deglaciated moraines. In both young and matured soils, those covered by a biological soil crust (biocrust) were more active than their bare counterparts. Isotopic analysis showed that in both cases CH4 was initially produced from H2/CO2 but later mostly from acetate. Analysis of the archaeal community in the in situ soil samples revealed a clear dominance of sequences related to Thaumarchaeota, while the methanogenic community comprised only a minor fraction of the archaeal community. Similar to other aerated soils, the methanogenic community was comprised almost solely of the genera Methanosarcina and Methanocella, and possibly also Methanobacterium in some cases. Nevertheless, ~103 gdw−1 soil methanogens were already present in the young moraine soil together with cyanobacteria. Our results demonstrate that Methanosarcina and Methanocella not only tolerate atmospheric oxygen but are also able to survive in these harsh cold environments. Their occurrence in newly deglaciated soils shows that they are early colonizers of desert soils, similar to cyanobacteria, and may play a role in the development of desert biocrusts. PMID:24348469

Improved exposure estimation in soil screening and cleanup criteria for volatile organic chemicals.

PubMed

DeVaull, George E

2017-09-01

Soil cleanup criteria define acceptable concentrations of organic chemical constituents for exposed humans. These criteria sum the estimated soil exposure over multiple pathways. Assumptions for ingestion, dermal contact, and dust exposure generally presume a chemical persists in surface soils at a constant concentration level for the entire exposure duration. For volatile chemicals, this is an unrealistic assumption. A calculation method is presented for surficial soil criteria that include volatile depletion of chemical for these uptake pathways. The depletion estimates compare favorably with measured concentration profiles and with field measurements of soil concentration. Corresponding volatilization estimates compare favorably with measured data for a wide range of volatile and semivolatile chemicals, including instances with and without the presence of a mixed-chemical residual phase. Selected examples show application of the revised factors in estimating screening levels for benzene in surficial soils. Integr Environ Assess Manag 2017;13:861-869. © 2017 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC). © 2017 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

75 FR 82005 - Agency Information Collection Activities; Proposed Collection; Comment Request; Hazardous Waste...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-29

... hazardous waste or hazardous constituents to air, soil, or surface water. This information is also needed to... environment from hazardous waste accumulation practices, including contamination from equipment leaks and...

Unravelling Linkages between Plant Community Composition and the Pathogen-Suppressive Potential of Soils

PubMed Central

Latz, Ellen; Eisenhauer, Nico; Rall, Björn Christian; Scheu, Stefan; Jousset, Alexandre

2016-01-01

Plant diseases cause dramatic yield losses worldwide. Current disease control practices can be deleterious for the environment and human health, calling for alternative and sustainable management regimes. Soils harbour microorganisms that can efficiently suppress pathogens. Uncovering mediators driving their functioning in the field still remains challenging, but represents an essential step in order to develop strategies for increased soil health. We set up plant communities of varying richness to experimentally test the potential of soils differing in plant community history to suppress the pathogen Rhizoctonia solani. The results indicate that plant communities shape soil-disease suppression via changes in abiotic soil properties and the abundance of bacterial groups including species of the genera Actinomyces, Bacillus and Pseudomonas. Further, the results suggest that pairwise interactions between specific plant species strongly affect soil suppressiveness. Using structural equation modelling, we provide a pathway orientated framework showing how the complex interactions between plants, soil and microorganisms jointly shape soil suppressiveness. Our results stress the importance of plant community composition as a determinant of soil functioning, such as the disease suppressive potential of soils. PMID:27021053

Feasibility analysis of EDXRF method to detect heavy metal pollution in ecological environment

NASA Astrophysics Data System (ADS)

Hao, Zhixu; Qin, Xulei

2018-02-01

The change of heavy metal content in water environment, soil and plant can reflect the change of heavy metal pollution in ecological environment, and it is important to monitor the trend of heavy metal pollution in eco-environment by using water environment, soil and heavy metal content in plant. However, the content of heavy metals in nature is very low, the background elements of water environment, soil and plant samples are complex, and there are many interfering factors in the EDXRF system that will affect the spectral analysis results and reduce the detection accuracy. Through the contrastive analysis of several heavy metal elements detection methods, it is concluded that the EDXRF method is superior to other chemical methods in testing accuracy and method feasibility when the heavy metal pollution in soil is tested in ecological environment.

Arsenic and Heavy Metal Contamination in Soils under Different Land Use in an Estuary in Northern Vietnam

PubMed Central

Nguyen Van, Thinh; Ozaki, Akinori; Nguyen Tho, Hoang; Nguyen Duc, Anh; Tran Thi, Yen; Kurosawa, Kiyoshi

2016-01-01

Heavy metal contamination of soil and sediment in estuaries warrants study because a healthy estuarine environment, including healthy soil, is important in order to achieve ecological balance and good aquaculture production. The Ba Lat estuary of the Red River is the largest estuary in northern Vietnam and is employed in various land uses. However, the heavy metal contamination of its soil has not yet been reported. The following research was conducted to clarify contamination levels, supply sources, and the effect of land use on heavy metal concentrations in the estuary. Soil samples were collected from the top soil layer of the estuary, and their arsenic (As), chromium (Cr), cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) concentrations were analyzed, as were other soil properties. Most soils in the estuary were loam, silt loam, or sandy loam. The pH was neutral, and the cation exchange capacity ranged from 3.8 to 20 cmol·kg−1. Manganese and iron concentrations averaged 811 µg·g−1 and 1.79%, respectively. The magnitude of the soil heavy metal concentrations decreased in the order of Zn > Pb > Cr > Cu > As > Cd. The concentrations were higher in the riverbed and mangrove forest than in other land-use areas. Except for As, the mean heavy metal concentrations were lower than the permissible levels for agricultural soils in Vietnam. The principal component analyses suggested that soil As, Pb, Zn, Cd, and Cu were of anthropogenic origin, whereas Cr was of non-anthropogenic origin. The spatial distribution of concentration with land use indicated that mangrove forests play an important role in preventing the spread of heavy metals to other land uses and in maintaining the estuarine environment. PMID:27827965

Arsenic and Heavy Metal Contamination in Soils under Different Land Use in an Estuary in Northern Vietnam.

PubMed

Nguyen Van, Thinh; Ozaki, Akinori; Nguyen Tho, Hoang; Nguyen Duc, Anh; Tran Thi, Yen; Kurosawa, Kiyoshi

2016-11-05

Heavy metal contamination of soil and sediment in estuaries warrants study because a healthy estuarine environment, including healthy soil, is important in order to achieve ecological balance and good aquaculture production. The Ba Lat estuary of the Red River is the largest estuary in northern Vietnam and is employed in various land uses. However, the heavy metal contamination of its soil has not yet been reported. The following research was conducted to clarify contamination levels, supply sources, and the effect of land use on heavy metal concentrations in the estuary. Soil samples were collected from the top soil layer of the estuary, and their arsenic (As), chromium (Cr), cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) concentrations were analyzed, as were other soil properties. Most soils in the estuary were loam, silt loam, or sandy loam. The pH was neutral, and the cation exchange capacity ranged from 3.8 to 20 cmol·kg -1 . Manganese and iron concentrations averaged 811 µg·g -1 and 1.79%, respectively. The magnitude of the soil heavy metal concentrations decreased in the order of Zn > Pb > Cr > Cu > As > Cd. The concentrations were higher in the riverbed and mangrove forest than in other land-use areas. Except for As, the mean heavy metal concentrations were lower than the permissible levels for agricultural soils in Vietnam. The principal component analyses suggested that soil As, Pb, Zn, Cd, and Cu were of anthropogenic origin, whereas Cr was of non-anthropogenic origin. The spatial distribution of concentration with land use indicated that mangrove forests play an important role in preventing the spread of heavy metals to other land uses and in maintaining the estuarine environment.

Occurrence of non extractable pesticide residues in physical and chemical fractions of two soils

NASA Astrophysics Data System (ADS)

Andreou, Kostas; Semple, Kirk; Jones, Kevin

2010-05-01

Soils are considered to be a significant sink for organic contaminants, including pesticides, in the environment. Understanding the distribution and localisation of aged pesticide residues in soil is of great importance for assessing the mobility and availability of these chemicals in the environment. This study aimed to characterise the distribution of radiolabeled herbicide isoproturon and the radiolabeled insecticides diazinon and cypermethrin in two organically managed soils. The soils were spiked and aged under laboratory conditions for 17 months. The labile fraction of the pesticides residues was recovered in CaCl2 (0.01M) and then subjected to physical size fractionation using sedimentation and centrifugation steps, with >20μm, 20-2μm and 2-0.1μm soil factions collected. Further, the distribution of the pesticide residues in the organic matter of the fractionated soil was investigated using a sequential alkaline extraction (0.1N NaOH) into humic and fulvic acid and humin. Soil fractions of 20-2μm and 2-0.1μm had the largest burden of the 14C-residues. Different soil constituents have different capacities to form non-extractable residues. Soil solid fractions of 20-2 µm and <2 µm had far greater affinity to the 14C-pesticide residues than the coarser fraction (>20 µm). Fulvic acid showed to play a vital role in the formation and stabilisation of non-extractable 14C-pesticide residues in most cases.Assessment of the likelihood of the pesticide residues to become available to soil biota requires an understanding of the structure of the SOM matrix and the definition of the kinetics of the pesticide residues in different SOM pools as a function of the time.

Use of Geochemical Indices in Environmental Assessment of Soil; the Predictable and the Predictably Unpredictable

NASA Astrophysics Data System (ADS)

Mikkonen, Hannah; Clarke, Bradley; van de Graaff, Robert; Reichman, Suzie

2016-04-01

Geochemical correlations between common contaminants (Pb, Ni, As, Cr, Co and Zn) and earth metals, Fe and Mn, have been recommended as empirical tools to estimate "background" concentrations of metals in soil. A limited number of studies indicate that geochemical ratios between Pb, Ni, As, Cr, Co, V and Zn with scavenger metals Fe or Mn, are consistent between soils collected from different regions (Hamon et al. 2004, Myers and Thorbjornsen 2004). These studies have resulted in the incorporation of geochemical indices into Australian guidance, for derivation of ecological investigation levels for Ni, Cr, Cu and Zn. However, little research has been undertaken to assess the variation of geochemical patterns between soils derived from different parent materials or different weathering environments. A survey of background soils derived from four different parent materials, across Victoria, Australia, was undertaken, comprising collection of samples (n=640) from the surface (0 to 0.1 m) and sub-surface (0.3 to 0.6 m). Soil samples were collected from urban and rural areas of low disturbance, away from point sources of contamination. Samples were analysed for metals/metalloids and soil physical and chemical properties. Statistical review of results included regression and multivariate analysis. The results of the soil survey were compared against geochemical relationships reported within Australia and internationally. Compilation of results from this study and international data sets, indicates that geochemical relationships for metals Cr and V (in the format of log[Cr] = alog[Fe] +c) are predictable, not only between soils derived from different parent materials, but also between soils of different continents. Conversely, relationships between Zn and Fe, Pb and Fe, Cu and Fe, Co and Mn are variable, particularly within soils derived from alluvial sediments, which may have undergone periods of reducing conditions, resulting in dissociation from metal oxides. Broad application of geochemical indices without an understanding of site specific conditions could result in significant underestimation of anthropogenic impacts to soil and potential risks to the environment. The reliability and application of geochemical indices for estimation of background concentrations will be discussed, including comment on statistical limitations, (such as management of censored results and the behaviour of composition data) and miss-use/miss-interpretation of geochemical indices within the environmental assessment industry, including inferences of causation based on empirical relationships. HAMON, R. E., MCLAUGHLIN, M. J., GILKES, R. J., RATE, A. W., ZARCINAS, B., ROBERTSON, A., COZENS, G., RADFORD, N. & BETTENAY, L. 2004. Geochemical indices allow estimation of heavy metal background concentrations in soils. Global Biogeochemical Cycles, 18, GB1014. MYERS, J. & THORBJORNSEN, K. 2004. Identifying Metals Contamination in Soil: A Geochemical Approach. Soil & Sediment Contamination, 13, 1-16.

Index for characterizing post-fire soil environments in temperate coniferous forests

Treesearch

Theresa B. Jain; David S. Pilliod; Russell T. Graham; Leigh B. Lentile; Jonathan E. Sandquist

2012-01-01

Many scientists and managers have an interest in describing the environment following a fire to understand the effects on soil productivity, vegetation growth, and wildlife habitat, but little research has focused on the scientific rationale for classifying the post-fire environment. We developed an empirically-grounded soil post-fire index (PFI) based on available...

Estimating of Soil Texture Using Landsat Imagery: a Case Study in Thatta Tehsil, Sindh

NASA Astrophysics Data System (ADS)

Khalil, Zahid

2016-07-01

Soil texture is considered as an important environment factor for agricultural growth. It is the most essential part for soil classification in large scale. Today the precise soil information in large scale is of great demand from various stakeholders including soil scientists, environmental managers, land use planners and traditional agricultural users. With the increasing demand of soil properties in fine scale spatial resolution made the traditional laboratory methods inadequate. In addition the costs of soil analysis with precision agriculture systems are more expensive than traditional methods. In this regard, the application of geo-spatial techniques can be used as an alternative for examining soil analysis. This study aims to examine the ability of Geo-spatial techniques in identifying the spatial patterns of soil attributes in fine scale. Around 28 samples of soil were collected from the different areas of Thatta Tehsil, Sindh, Pakistan for analyzing soil texture. An Ordinary Least Square (OLS) regression analysis was used to relate the reflectance values of Landsat8 OLI imagery with the soil variables. The analysis showed there was a significant relationship (p<0.05) of band 2 and 5 with silt% (R2 = 0.52), and band 4 and 6 with clay% (R2 =0.40). The equation derived from OLS analysis was then used for the whole study area for deriving soil attributes. The USDA textural classification triangle was implementing for the derivation of soil texture map in GIS environment. The outcome revealed that the 'sandy loam' was in great quantity followed by loam, sandy clay loam and clay loam. The outcome shows that the Geo-spatial techniques could be used efficiently for mapping soil texture of a larger area in fine scale. This technology helped in decreasing cost, time and increase detailed information by reducing field work to a considerable level.

3D Visualisation and Artistic Imagery to Enhance Interest in "Hidden Environments"--New Approaches to Soil Science

ERIC Educational Resources Information Center

Gilford, J.; Falconer, R. E.; Wade, R.; Scott-Brown, K. C.

2014-01-01

Interactive Virtual Environments (VEs) have the potential to increase student interest in soil science. Accordingly a bespoke "soil atlas" was created using Java3D as an interactive 3D VE, to show soil information in the context of (and as affected by) the over-lying landscape. To display the below-ground soil characteristics, four sets…

The Changing Model of Soil

NASA Astrophysics Data System (ADS)

Richter, D. D.; Yaalon, D.

2012-12-01

The contemporary genetic model of soil is changing rapidly in response to advances in soil science and to human and environmental forcings in the 21st century (Richter and Yaalon, 2012). Three ongoing changes in the model of soil include that: (1) lower soil boundaries are much deeper than the solum, historically the O to B horizons, (2) most soils are polygenetic paleosols, products of soil-forming processes that have ranged widely over soils' lifetimes, and (3) soils are globally human-natural bodies, no longer natural bodies. Together, these changes in the model of soil mean that human forcings are a global wave of soil polygenesis altering fluxes of matter and energy and transforming soil thermodynamics as potentially very deep systems. Because soils are non-linear systems resulting from high-order interactions of physics, chemistry, and biology, trajectories of how human forcings alter soils over decades are not readily predictable and require long-term soil observations. There is much to learn about how soils are changing internally as central components of management systems and externally in relation to wider environments. To be critical, research has been remarkably superficial in studies of soil, reductionist in approach, and lacking in time-series observations of responses to soil management. While this criticism may sound negative, it creates significant opportunities for contemporary soil scientists.

Conference on Early Mars: Geologic and Hydrologic Evolution, Physical and Chemical Environments, and the Implications for Life

NASA Technical Reports Server (NTRS)

Clifford, S. M. (Editor); Treiman, A. H. (Editor); Newsom, H. E. (Editor); Farmer, J. D. (Editor)

1997-01-01

Topics considered include: Geology alteration and life in an extreme environment; developing a chemical code to identify magnetic biominerals; effect of impacts on early Martin geologic evolution; spectroscopic identification of minerals in Hematite-bearing soils and sediments; exopaleontology and the search for a Fossil record on Mars; geochemical evolution of the crust of Mars; geological evolution of the early earth;solar-wind-induced erosion of the Mars atmosphere. Also included geological evolution of the crust of Mars.

Teaching Soil Science in Primary and Secondary Schools

NASA Technical Reports Server (NTRS)

Levine, Elissa R.

1998-01-01

Earth's thin layer of soil is a fragile resource, made up of minerals, organic materials, air, water, and billions of living organisms. Soils plays a variety of critical roles that sustain life on Earth. If we think about soil, we tend to see it first as the source of most of the food we eat and the fibers we use, such as wood and cotton. Few students realize that soils also provide the key ingredients to many of the medicines (including antibiotics), cosmetics, and dyes that we use. Fewer still understand the importance of soils in integrating, controlling, and regulating the movement of air, water, materials, and energy between the hydrosphere, lithosphere, atmosphere, and biosphere. Because soil sustains life, it offers both a context and a natural laboratory for investigating these interactions. The enclosed poster, which integrates soil profiles with typical landscapes in which soils form, can also help students explore the interrelationships of Earth systems and gain an understanding of our soil resources. The poster, produced jointly by the American Geological Institute and the Soil Science Society of America, aims to increase awareness of the importance of soil, as does the GLOBE (Global Learning and Observations To Benefit the Environment) Program. Vice President Al Gore instituted the GLOBE Program on Earth Day of 1993 to increase environmental awareness of individuals throughout the world, contribute to a better scientific understanding of the Earth, and help all students reach higher levels of achievement in science and mathematics. GLOBE functions as a partnership between scientists, students, and teachers in which scientists design protocols for specific measurements they need for their research that can be performed by K-12 students. Teachers are trained in the GLOBE protocols and teach them to their students. Students make the measurements, enter data via the Internet to a central data archive, and the data becomes available to scientists and the general community. Students benefit by having a "hands-on"experience in science, math, and technology, using their local environment as a learning laboratory, as well as contact with scientists and other students around the world. Soil investigations have become an essential component of GLOBE. The protocols that have been developed so far within the GLOBE program include GPS Location, Atmosphere/Climate, Soil Characterization, Soil Moisture and Temperature, Land Cover/Biometry, Hydrology, and Satellite Image Classification. For the GLOBE Soil Characterization Protocol, students explore the physical. chemical, and morphological properties of the soil at their study site. They are asked to dig a pit or use an auger to about 1 meter at at least 2 sites.

Determination of nitrogen balance in agroecosystems.

PubMed

Sainju, Upendra M

2017-01-01

Nitrogen balance in agroecosystems provides a quantitative framework of N inputs and outputs and retention in the soil that examines the sustainability of agricultural productivity and soil and environmental quality. Nitrogen inputs include N additions from manures and fertilizers, atmospheric depositions including wet and dry depositions, irrigation water, and biological N fixation. Nitrogen outputs include N removal in crop grain and biomass and N losses through leaching, denitrification, volatilization, surface runoff, erosion, gas emissions, and plant senescence. Nitrogen balance, which is the difference between N inputs and outputs, can be reflected in changes in soil total (organic + inorganic) N during the course of the experiment duration due to N immobilization and mineralization. While increased soil N retention and mineralization can enhance crop yields and decrease N fertilization rate, reduced N losses through N leaching and gas emissions (primarily NH 4 and NO x emissions, out of which N 2 O is a potent greenhouse gas) can improve water and air quality. •This paper discusses measurements and estimations (for non-measurable parameters due to complexity) of all inputs and outputs of N as well as changes in soil N storage during the course of the experiment to calculate N balance.•The method shows N flows, retention in the soil, and losses to the environment from agroecosystems.•The method can be used to measure agroecosystem performance and soil and environmental quality from agricultural practices.

Electrical resistivity imaging study of near-surface infiltration

NASA Astrophysics Data System (ADS)

Lampousis, Angelos

High resolution electrical resistivity images (ERI method) were obtained during vadose zone infiltration experiments on agricultural soils in cooperation with Cornell University's Agricultural Stewardship Program, Cooperative Extension of Suffolk County, Extension Education Center, Riverhead, New York [ as well as Cornell University's Long Island Horticultural Research & Extension Center (LIHREC) in Riverhead, New York]. One natural soil was also studied. Infiltration was monitored by means of image analysis of two-dimensional array resistivity generated by a Syscal Kid Switch resistivity system (Griffiths et al., 1990). The data was inverted with the computer program RES2DINV (Loke, 2004). The agricultural soils considered were Riverhead sandy loam (RdA), Haven loam (HaA), and Bridgehampton silt loam (BgA). The natural site was located in the Catskill Mountains of New York State. The soils there are classified as Schoharie silty clay loam. The electrical images of the three sites were compared against established soil properties, including particle size distribution, available water capacity, and soluble salts (from the literature), as well as against site-specific soil samples and penetrometer data, which were collected along with the geophysical measurements. This research evaluates the potential of acquiring high resolution, non-destructive measurements of infiltration in the uppermost 1.5 meter of the vadose zone. The results demonstrate that resistivity differences can detect infiltration in soils typical of the north-eastern United States. Temporal and spatial variations of soil water content in the upper 1.5 meters (relevant to agriculture) of the subsurface can be monitored successfully and non-destructively with ERI. The sensitivity of the method is higher in subsurface environments that demonstrate high overall apparent resistivity values (e.g. high sand content). Under conditions of increased soil heterogeneity, instead of the formation of a continuous water plume as occurred in the homogeneous agricultural soils, the location of the infiltrated water seems to be highly influenced by the soil heterogeneity, and the water front is scattered into discontinuous layers and travels in additional directions. The geophysical results during infiltration correlate well with soil compaction data. It follows that the ERI method can be used as a proxy for soil compaction and water content variations in agricultural applications. In a natural environment, ERI successfully maps the tree root zone of mature trees. Applications include continuous water content monitoring in high value cash crops, such as viticulture (precision agriculture).

Serpentine Soils Do Not Limit Mycorrhizal Fungal Diversity

PubMed Central

Branco, Sara; Ree, Richard H.

2010-01-01

Background Physiologically stressful environments tend to host depauperate and specialized biological communities. Serpentine soils exemplify this phenomenon by imposing well-known constraints on plants; however, their effect on other organisms is still poorly understood. Methodology/Principal Findings We used a combination of field and molecular approaches to test the hypothesis that serpentine fungal communities are species-poor and specialized. We conducted surveys of ectomycorrhizal fungal diversity from adjacent serpentine and non-serpentine sites, described fungal communities using nrDNA Internal Transcribed Spacer (ITS) fragment and sequence analyses, and compared their phylogenetic community structure. Although we detected low fungal overlap across the two habitats, we found serpentine soils to support rich fungal communities that include representatives from all major fungal lineages. We failed to detect the phylogenetic signature of endemic clades that would result from specialization and adaptive radiation within this habitat. Conclusions/Significance Our results indicate that serpentine soils do not constitute an extreme environment for ectomycorrhizal fungi, and raise important questions about the role of symbioses in edaphic tolerance and the maintenance of biodiversity. PMID:20668696

The astonishingly holistic role of urban soil in the exposure of children to lead.

NASA Astrophysics Data System (ADS)

Mielke, Howard; Gonzales, Christopher; Powell, Eric

2017-04-01

The long-term resilience and sustainability of urban communities is associated with its environmental quality. One major impediment to community welfare is children's exposure to lead because it is a root cause of disparity and chronic conditions including health, learning, and behavioral differences. There is no safe level of lead exposure and this revelation is confounded by the lack of an effective intervention after exposure takes place. In August, 2005, Hurricane Katrina flooded 80% of New Orleans. This report explores the natural experiment of the dynamic changes of soil and children's blood lead in New Orleans before and ten years after the flood. Matched pre- and post-Hurricane soil lead and children's blood lead results were stratified by 172 communities of New Orleans. GIS methods were used to organize, describe, and map the pre- and post-Katrina data. Comparing pre- and post-Katrina results, simultaneous decreases occurred in soil lead and children's blood lead response. Health and welfare disparities continue to exist between environments and children's exposure living in interior compared with outer communities of the city. At the scale of a city this investigation demonstrates that declining soil lead effectively reduces children's blood lead. The astonishingly holistic role of soil relates to its position as a lead dust deposition reservoir and, at the same time, as an open source of ingestible and inhalable lead dust. Decreasing the soil lead on play areas of urban communities is beneficial and economical as a method for effective lead intervention and primary prevention. References Mielke, H.W.; Gonzales, C.R.; Powell, E.T.; Mielke, P.W. Jr. Spatiotemporal dynamic transformations of soil lead and children's blood lead ten years after Hurricane Katrina: New grounds for primary prevention. Environ. Int. 2016, DOI: 10.1016/j.envint.2016.06.017. Mielke, H.W.; Gonzales, C.R.; Powell, E.T. In review. The dynamic lead exposome and children's health in New Orleans pre-and post-Hurricane Katrina. Int. J. Environ. Res. Public Health

Prediction and inter-dependence of stock and change of soil quality, function and diversity at a national scale and implications for ecosystem services

NASA Astrophysics Data System (ADS)

Reynolds, B.; Emmett, B.; Spurgeon, D.; Rowe, E. C.; Mills, R.; Griffiths, R.; Jones, D.; Simfukwe, P.

2011-12-01

A soils monitoring programme which uses an ecosystem approach has been in place in Great Britain for 30 years.The findings from the latest survey in 2007 has been interpreted within a natural capital and ecosystem services context to assess the outcome of a range of policies to protect the natural environment and increase sustainability. Issues of interest included the impacts of declines in atmospheric deposition of acidity, nitrogen and metals, the benefits of agri-environment schemes and climate change on carbon storage in soils and soil biodiversity, and reduced fertiliser applications on eutrophication of soils and waters. Topsoil samples (0-15cm) were taken within 600 1km squares across the country stratified to cover all major habitat types. At the same time botanical surveys in permanent vegetation plots were recorded together with change in land use and management and stream and pond water quality and ecology. These data are used together with satellite images, digital cartography, and ancillary datasets to assess change in landcover for all of GB and upscaling of change data from the samples squares. Changes in topsoil were assessed in 1978, 1998 and again in 2007. An increase in pH but no change in soil carbon was observed between 1978 and 2007. Additional measures added in 1998 enabled a decline in Olsen-P,increase in C:N, decline in soil mesofauna diversity and decline in many metal concentrations to be identified over the last 10 years. In 2007, futher measurements were added to include carbon substrate utilisation, nitrogen mineralisation and bacterial diversity (fungi is in progress)enabling national maps to be created for the first time for these important soil parameters. Multi-variate statistics were used to explore the relationship between the different soil measures, the predictive capability of soil and vegetation type, and drivers of change to be identified. In addition, assigning measurements to specific functions which underpinned individual supporting and regulation services provided a method for assessing direction of change of a range of ecosystem services at national scale for the first time.

The impact of warfare on the soil environment

NASA Astrophysics Data System (ADS)

Certini, Giacomo; Scalenghe, Riccardo; Woods, William I.

2013-12-01

One of the most dramatic ways humans can affect soil properties is through the performance of military activities. Warfare-induced disturbances to soil are basically of three types - physical, chemical, and biological - and are aimed at causing direct problems to enemies or, more often, are indirect, undesired ramifications. Physical disturbances to soil include sealing due to building of defensive infrastructures, excavation of trenches or tunnels, compaction by traffic of machinery and troops, or cratering by bombs. Chemical disturbances consist of the input of pollutants such as oil, heavy metals, nitroaromatic explosives, organophosphorus nerve agents, dioxins from herbicides, or radioactive elements. Biological disturbances occur as unintentional consequences of the impact on the physical and chemical properties of soil or the deliberate introduction of microorganisms lethal to higher animals and humans such as botulin or anthrax. Soil represents a secure niche where such pathogens can perpetuate their virulence for decades.

Variation in Soil Respiration across Soil and Vegetation Types in an Alpine Valley

PubMed Central

Rubin, Aurélie

2016-01-01

Background and Aims Soils of mountain regions and their associated plant communities are highly diverse over short spatial scales due to the heterogeneity of geological substrates and highly dynamic geomorphic processes. The consequences of this heterogeneity for biogeochemical transfers, however, remain poorly documented. The objective of this study was to quantify the variability of soil-surface carbon dioxide efflux, known as soil respiration (Rs), across soil and vegetation types in an Alpine valley. To this aim, we measured Rs rates during the peak and late growing season (July-October) in 48 plots located in pastoral areas of a small valley of the Swiss Alps. Findings Four herbaceous vegetation types were identified, three corresponding to different stages of primary succession (Petasition paradoxi in pioneer conditions, Seslerion in more advanced stages and Poion alpinae replacing the climactic forests), as well as one (Rumicion alpinae) corresponding to eutrophic grasslands in intensively grazed areas. Soils were developed on calcareous alluvial and colluvial fan deposits and were classified into six types including three Fluvisols grades and three Cambisols grades. Plant and soil types had a high level of co-occurrence. The strongest predictor of Rs was soil temperature, yet we detected additional explanatory power of sampling month, showing that temporal variation was not entirely reducible to variations in temperature. Vegetation and soil types were also major determinants of Rs. During the warmest month (August), Rs rates varied by over a factor three between soil and vegetation types, ranging from 2.5 μmol m-2 s-1 in pioneer environments (Petasition on Very Young Fluvisols) to 8.5 μmol m-2 s-1 in differentiated soils supporting nitrophilous species (Rumicion on Calcaric Cambisols). Conclusions Overall, this study provides quantitative estimates of spatial and temporal variability in Rs in the mountain environment, and demonstrates that estimations of soil carbon efflux at the watershed scale in complex geomorphic terrain have to account for soil and vegetation heterogeneity. PMID:27685955

Environmental impact and bioremediation of seleniferous soils and sediments.

PubMed

Wadgaonkar, Shrutika L; Nancharaiah, Yarlagadda V; Esposito, Giovanni; Lens, Piet N L

2018-01-05

Selenium concentrations in the soil environment are directly linked to its transfer in the food chain, eventually causing either deficiency or toxicity associated with several physiological dysfunctions in animals and humans. Selenium bioavailability depends on its speciation in the soil environment, which is mainly influenced by the prevailing pH, redox potential, and organic matter content of the soil. The selenium cycle in the environment is primarily mediated through chemical and biological selenium transformations. Interactions of selenium with microorganisms and plants in the soil environment have been studied in order to understand the underlying interplay of selenium conversions and to develop environmental technologies for efficient bioremediation of seleniferous soils. In situ approaches such as phytoremediation, soil amendment with organic matter and biovolatilization are promising for remediation of seleniferous soils. Ex situ remediation of contaminated soils by soil washing with benign leaching agents is widely considered for removing heavy metal pollutants. However, it has not been applied until now for remediation of seleniferous soils. Washing of seleniferous soils with benign leaching agents and further treatment of Se-bearing leachates in bioreactors through microbial reduction will be advantageous as it is aimed at removal as well as recovery of selenium for potential re-use for agricultural and industrial applications. This review summarizes the impact of selenium deficiency and toxicity on ecosystems in selenium deficient and seleniferous regions across the globe, and recent research in the field of bioremediation of seleniferous soils.

What's so critical about the critical zone?: New insights at the boundaries between hydrology, pedology, geomorphology, rocks and life (Invited)

NASA Astrophysics Data System (ADS)

Grant, G.

2013-12-01

The great promise of critical zone science and observatories (CZOs) emerging over the past decade was that real progress towards understanding the earth's near-surface environment could be made through coordinated studies of processes and interactions that occur within that thin layer between the bottom of the atmosphere and the top of competent bedrock - the critical zone. How well has this promise been realized, and where is the science now headed? Drawing on recent findings from CZOs and elsewhere, I identify a number of exciting and potentially transformative new ideas and threads at the boundaries of hydrology, geomorphology, pedology, and ecology. These include: 1). New understanding of interactions and feedbacks among soil weathering, pathways for water, tree roots, and bedrock fractures. A fundamental insight emerging from critical zone studies is that soils are far more interestingly structured than simple textbook models of homogeneous substrates with exponentially decreasing permeability with depth. Instead, the near-surface is now seen as a complex network of voids, paths, conduits, and storage zones that are both formed and exploited by the movement of water, geochemical reactions, and organisms. This evolving perspective on the critical zone has implications for a wide range of issues, including the residence time and chemistry of water, rates of weathering, slope stability, and long-term soil fertility. 2. Growing appreciation for the role of biology in conditioning and transforming its own physical environment within the critical zone. This includes the role of trees in hydraulically redistributing water, fracturing bedrock, and contributing to long-term soil erosion and landscape evolution through tree fall and throw and vegetation effects on moisture regimes. 3. Similarly, the importance of understanding linkages among soils, water, and vegetation has never been greater as a warming climate dramatically changes the 'rules of the game'. New understanding of feedbacks among vegetation growth and water uptake, soil moisture regimes, snowpack dynamics, and overall forest health are challenging previous assumptions about how best to manage forest environments in the face of a warming atmosphere and increased frequencies of disturbance. Time will tell whether these new perspectives represent incremental or fundamental shifts in our thinking about the critical zone, but it is clearly an exciting time for critical zone science and scientists.

Selected micrometeorological, soil-moisture, and evapotranspiration data at Amargosa Desert Research Site in Nye County near Beatty, Nevada, 2001-05

USGS Publications Warehouse

Johnson, Michael J.; Mayers, C. Justin; Garcia, C. Amanda; Andraski, Brian J.

2007-01-01

Selected micrometeorological and soil-moisture data were collected at the Amargosa Desert Research Site adjacent to a low-level radio-active waste and hazardous chemical waste facility near Beatty, Nevada, 2001-05. Evapotranspiration data were collected from February 2002 through the end of December 2005. Data were col-lected in support of ongoing research to improve the understanding of hydrologic and contaminant-transport processes in arid environments. Micrometeorological data include solar radiation, net radiation, air temperature, relative humidity, saturated and ambient vapor pressure, wind speed and direction, barometric pressure, precipitation, near-surface soil temperature, soil-heat flux and soil-water content. All micrometeorological data were collected using a 10-second sampling interval by data loggers that output daily and hourly mean values. Daily maximum and minimum values are based on hourly mean values. Precipitation data output includes daily and hourly totals. Selected soil-moisture profiles at depth include periodic measurements of soil volumetric water-content measurements at nine neutron-probe access tubes to depths ranging from 5.25 to 29.25 meters. Evapotranspiration data include measurement of daily evapotranspiration and 15-minute fluxes of the four principal energy budget components of latent-heat flux, sensible-heat flux, soil-heat flux, and net radiation. Other data collected and used in equations to determine evapotranspiration include temperature and water content of soil, temperature and vapor pressure of air, and covariance values. Evapotranspiration and flux estimates during 15-minute intervals were calculated at a 0.1-second execution interval using the eddy covariance method. Data files included in this report contain the complete micrometeorological, soil-moisture, and evapotranspiration field data sets. These data files are presented in tabular Excel spreadsheet format. This report highlights selected data contained in the computer generated data files using figures, tables, and brief discussions. Instrumentation used for data collection also is described. Water-content profiles are shown to demonstrate variability of water content with depth. Time-series data are plotted to illustrate temporal variations in micrometeorological, soil-water content, and evapotranspiration data.

[Review on water eco-environment in vegetation restoration in Loess Plateau].

PubMed

Hu, Liangjun; Shao, Mingan

2002-08-01

Water is the crucial factor influencing vegetation restoration and eco-environmental reconstruction in Loess Plateau region. In this paper, the previous studies on water eco-environment under vegetation construction were summarized from seven aspects, i.e., soil water resource, background of soil water, dynamics of soil water, dry soil layer, relationship between soil water and vegetarian productivity, classification of soil water position, and strategy for vegetation construction. Meanwhile, some problems in the relevant researches were pointed out and discussed.

SOIL - A new open access journal of the European Geosciences Union

NASA Astrophysics Data System (ADS)

Brevik, Eric; Mataix-Solera, Jorge; Pereg, Lily; Quinton, John; Six, Johan; Van Oost, Kristof; Cerdà, Artemi

2014-05-01

The Soil System Sciences (SSS) division of the EGU has been a strong and growing international research force in the last few years. Since the first EGU meeting with SSS participation in 2004 where 200 abstracts were presented in 7 sessions, the contribution of the SSS division has grown considerably, with 1,427 abstracts presented in 57 SSS sessions at the 2013 EGU General Assembly. After 10 years of active participation, the SSS Division has developed a new open access journal, SOIL, which will serve the whole EGU membership. SOIL intends to publish scientific research that will contribute to understanding the Soil System and its interaction with humans and the entire Earth System. The scope of the journal will include all topics that fall within the study of soil science as a discipline, with an emphasis on studies that integrate soil science with other sciences (Soils and plants, Soils and water, Soils and atmosphere, Soils and biogeochemical cycling, Soils and the natural environment, Soils and the human environment, Soils and food security, Soils and biodiversity, Soils and global change, Soils and health, Soil as a resource, Soil systems, Soil degradation (chemical, physical and biological), Soil protection and remediation (including soil monitoring), Soils and methodologies). Manuscript types considered for publication in SOIL are original research articles, review articles, short communications, forum articles, and letters to the editors. SOIL will also publish up to two special issues on thematic subjects per year and encourages conveners of innovative sessions at the EGU meeting to submit proposals for special issues to the executive editor who oversees special issues. As with other EGU journals, SOIL has a two-stage publication process. In the first stage, papers that pass a rapid access-review by one of the editors will immediately be published in SOIL Discussions (SOIL-D). Papers will then be subject to interactive public discussion, during which the referees' comments (anonymous or attributed), additional short comments by other members of the scientific community (attributed), and the author's replies will also be published in SOIL-D. In the second stage, a peer-review and revision process is completed and, if accepted, finalized papers are published in SOIL. To ensure publication precedence for authors, and to provide a lasting record of scientific discussion, SOIL-D and SOIL are both ISSN-registered, permanently archived, and fully citable. SOIL has a team of five executive editors who work together to oversee the running of the journal. Those executive editors, and their areas of primary oversight, are Eric Brevik (Review Article Editor), Jorge Mataix-Solera (Special Issues Editor), John Quinton (Awards and Recognitions Editor), Johan Six (Managing Editor), and Kristof Van Oost (Forum Article Editor). SOIL also has 46 associate editors. Manuscripts can be submitted to SOIL at the journal's website (http://www.soil-journal.net/home.html) beginning in May 2014. The first issue will be published January of 2015. Publication fees will be waived for the first two years of publication.

The fate of arsenic in soil-plant systems.

PubMed

Moreno-Jiménez, Eduardo; Esteban, Elvira; Peñalosa, Jesús M

2012-01-01

Arsenic is a natural trace element found in the environment. In some cases and places, human activities have increased the soil concentration of As to levels that exceed hazard thresholds. Amongst the main contributing sources of As contamination of soil and water are the following: geologic origin, pyriticmining, agriculture, and coal burning. Arsenic speciation in soils occurs and is relatively complex. Soils contain both organic and inorganic arsenic species. Inorganic As species include arsenite and arsenate, which are the most abundant forms found in the environment. The majority of As in aerated soils exists as H₂AsO₄- (acid soils) or HAsO₄²- (neutral species and basic). However, HA₃sO₃ is the predomiant anaerobic soils, where arsenic availability is higher and As(III) is more weakly retained in the soil matrix than is As(V). The availability of As in soils is usually driven by multiple factors. Among these factors is the presence of Fe-oxides and/or phosphorus, (co)precipitation in salts, pH, organic matter, clay content, rainfall amount, etc. The available and most labile As fraction can potentially be taken up by plant roots, although the concentration of this fraction is usually low. Arsenic has no known biological function in plants. Once inside root cells, As(V) is quickly reduced to As(III), and, in many plant species, becomes complexed. Phosphorus nutrition influences As(V) uptake and toxicity in plants, whilst silicon has similar influences on As(III). Plants cope with As contamination in their tissues by possessing detoxification mechanisms. Such mechanisms include complexation and compartmentalization. However, once these mechanisms are saturated, symptoms of phytotoxicity appear. Phytotoxic effects commonly observed from As exposure includes growth inhibition, chlorophyll degradation, nutrient depletion and oxidative stress. Plants vary in their ability to accumulate and tolerate As (from tolerant hyperaccumulators to sensitive excluders), and some plants are useful for soil reclamation and in sustainable agriculture, The status of current scientific knowledge allows us to manage As contamination in the soil-plant system and to mitigate arsenic's effects. Phytoremediation is an emerging technology suitable for reclaiming As-contaminated soils and waters. Phytoextraction has been used to clean As-contaminated soils, although its applicability has not yet reached maturity. Phytostabilization has been employed to reduce environmental risk by confining As as an inert form in soils and has shown success in both laboratory experiments and in field trials. Phytofiltration has been used to treat As-enriched waters. Such treatment removes As when it is accumulated in plants grown in or on water. In agricultural food production, appropriate soil management and plant variety/species selection can minimize As-associated human dis- eases and the transfer of As within the food chain. Selecting suitable plants for use on As-contaminated soils may also enhance alternative land use, such as for energy or raw material production.

Distinct respiratory responses of soils to complex organic substrate are governed predominantly by soil architecture and its microbial community.

PubMed

Fraser, F C; Todman, L C; Corstanje, R; Deeks, L K; Harris, J A; Pawlett, M; Whitmore, A P; Ritz, K

2016-12-01

Factors governing the turnover of organic matter (OM) added to soils, including substrate quality, climate, environment and biology, are well known, but their relative importance has been difficult to ascertain due to the interconnected nature of the soil system. This has made their inclusion in mechanistic models of OM turnover or nutrient cycling difficult despite the potential power of these models to unravel complex interactions. Using high temporal-resolution respirometery (6 min measurement intervals), we monitored the respiratory response of 67 soils sampled from across England and Wales over a 5 day period following the addition of a complex organic substrate (green barley powder). Four respiratory response archetypes were observed, characterised by different rates of respiration as well as different time-dependent patterns. We also found that it was possible to predict, with 95% accuracy, which type of respiratory behaviour a soil would exhibit based on certain physical and chemical soil properties combined with the size and phenotypic structure of the microbial community. Bulk density, microbial biomass carbon, water holding capacity and microbial community phenotype were identified as the four most important factors in predicting the soils' respiratory responses using a Bayesian belief network. These results show that the size and constitution of the microbial community are as important as physico-chemical properties of a soil in governing the respiratory response to OM addition. Such a combination suggests that the 'architecture' of the soil, i.e. the integration of the spatial organisation of the environment and the interactions between the communities living and functioning within the pore networks, is fundamentally important in regulating such processes.

Expression of allelopathy in the soil environment: Soil concentration and activity of benzoxazinoid compounds released by rye cover crop residue

USDA-ARS?s Scientific Manuscript database

The activity of allelopathic compounds is often reduced in the soil environment where processes involving release from donor plant material, soil adsorption and degradation, and uptake by receptor plants naturally result in complex interactions. Rye (Secale cereale L.) cover crops are known to supp...

Envirotyping for deciphering environmental impacts on crop plants.

PubMed

Xu, Yunbi

2016-04-01

Global climate change imposes increasing impacts on our environments and crop production. To decipher environmental impacts on crop plants, the concept "envirotyping" is proposed, as a third "typing" technology, complementing with genotyping and phenotyping. Environmental factors can be collected through multiple environmental trials, geographic and soil information systems, measurement of soil and canopy properties, and evaluation of companion organisms. Envirotyping contributes to crop modeling and phenotype prediction through its functional components, including genotype-by-environment interaction (GEI), genes responsive to environmental signals, biotic and abiotic stresses, and integrative phenotyping. Envirotyping, driven by information and support systems, has a wide range of applications, including environmental characterization, GEI analysis, phenotype prediction, near-iso-environment construction, agronomic genomics, precision agriculture and breeding, and development of a four-dimensional profile of crop science involving genotype (G), phenotype (P), envirotype (E) and time (T) (developmental stage). In the future, envirotyping needs to zoom into specific experimental plots and individual plants, along with the development of high-throughput and precision envirotyping platforms, to integrate genotypic, phenotypic and envirotypic information for establishing a high-efficient precision breeding and sustainable crop production system based on deciphered environmental impacts.

Weathering and aging of 2,4,6-trinitrotoluene in soil increases toxicity to potworm Enchytraeus crypticus.

PubMed

Kuperman, Roman G; Checkai, Ronald T; Simini, Michael; Phillips, Carlton T; Kolakowski, Jan E; Kurnas, Carl W

2005-10-01

Energetic materials are employed in a wide range of commercial and military activities and often are released into the environment. Scientifically based ecological soil-screening levels (Eco-SSLs) are needed to identify contaminant explosive levels in soil that present an acceptable ecological risk. Insufficient information for 2,4,6-trinitrotoluene (TNT) to generate Eco-SSLs for soil invertebrates necessitated toxicity testing. We adapted the standardized Enchytraeid Reproduction Test and selected Enchytraeus crypticus for these studies. Tests were conducted in Sassafras sandy loam soil, which supports relatively high bioavailability of TNT. Weathering and aging procedures for TNT amended to test soil were incorporated into the study design to produce toxicity data that better reflect the soil exposure conditions in the field compared with toxicity in freshly amended soils. This included exposing hydrated TNT-amended soils in open glass containers in the greenhouse to alternating wetting and drying cycles. Definitive tests showed that toxicity for E. crypticus adult survival and juvenile production was increased significantly in weathered and aged soil treatments compared with toxicity in freshly amended soil based on 95% confidence intervals. The median effect concentration and 20% effective concentration for reproduction were 98 and 77 mg/kg, respectively, for TNT freshly amended into soil and 48 and 37 mg/kg, respectively, for weathered and aged TNT soil treatments. These findings of increased toxicity to E. crypticus in weathered and aged TNT soil treatments compared with exposures in freshly amended soils show that future investigations should include a weathering and aging component to generate toxicity data that provide more complete information on ecotoxicological effects of energetic contaminants in soil.

Biological Remediation of Petroleum Contaminants

NASA Astrophysics Data System (ADS)

Kuhad, Ramesh Chander; Gupta, Rishi

Large volumes of hazardous wastes are generated in the form of oily sludges and contaminated soils during crude oil transportation and processing. Although many physical, chemical and biological treatment technologies are available for petroleum contaminants petroleum contaminants in soil, biological methods have been considered the most cost-effective. Practical biological remediation methods typically involve direct use of the microbes naturally occurring in the contaminated environment and/or cultured indigenous or modified microorganisms. Environmental and nutritional factors, including the properties of the soil, the chemical structure of the hydrocarbon(s), oxygen, water, nutrient availability, pH, temperature, and contaminant bioavailability, can significantly affect the rate and the extent of hydrocarbon biodegradation hydrocarbon biodegradation by microorganisms in contaminated soils. This chapter concisely discusses the major aspects of bioremediation of petroleum contaminants.

ISRU Soil Mechanics Vacuum Facility: Soil Bin Preparation and Simulant Strength Characterization

NASA Technical Reports Server (NTRS)

Kleinhenz, Julie; Wilkinson, Allen

2012-01-01

Testing in relevant environments is key to exploration mission hardware development. This is true on both the component level (in early development) and system level (in late development stages). During ISRU missions the hardware will interface with the soil (digging, roving, etc) in a vacuum environment. A relevant test environment will therefore involve a vacuum chamber with a controlled, conditioned simulant bed. However, in earth-based granular media, such as lunar soil simulant, gases trapped within the material pore structures and water adsorbed to all particle surfaces will release when exposed to vacuum. Early vacuum testing has shown that this gas release can occur violently, which loosens and weakens the simulant, altering the consolidation state. The Vacuum Facility #13, a mid-size chamber (3.66m tall, 1.5m inner diameter) at the NASA Glenn Research Center has been modified to create a soil mechanics test facility. A 0.64m deep by 0.914m square metric ton bed of lunar simulant was placed under vacuum using a variety of pumping techniques. Both GRC-3 and LHT-3M simulant types have been used. An electric cone penetrometer was used to measure simulant strength properties at vacuum including: cohesion, friction angle, bulk density and shear modulus. Simulant disruptions, caused by off gassing, affected the strength properties, but could be mitigated by reducing pump rate. No disruptions were observed at pressures below 2.5Torr, regardless of the pump rate. However, slow off gassing of the soil lead to long test times, a full week, to reach 10-5Torr. This work highlights the need for robotic machine-simulant hardware and operations in vacuum to expeditiously perform (sub-)systems tests.

Arbuscular Mycorhizal Fungi Associated with the Olive Crop across the Andalusian Landscape: Factors Driving Community Differentiation

PubMed Central

Montes-Borrego, Miguel; Metsis, Madis; Landa, Blanca B.

2014-01-01

Background In the last years, many olive plantations in southern Spain have been mediated by the use of self-rooted planting stocks, which have incorporated commercial AMF during the nursery period to facilitate their establishment. However, this was practised without enough knowledge on the effect of cropping practices and environment on the biodiversity of AMF in olive orchards in Spain. Methodology/Principal Findings Two culture-independent molecular methods were used to study the AMF communities associated with olive in a wide-region analysis in southern Spain including 96 olive locations. The use of T-RFLP and pyrosequencing analysis of rDNA sequences provided the first evidence of an effect of agronomic and climatic characteristics, and soil physicochemical properties on AMF community composition associated with olive. Thus, the factors most strongly associated to AMF distribution varied according to the technique but included among the studied agronomic characteristics the cultivar genotype and age of plantation and the irrigation regimen but not the orchard management system or presence of a cover crop to prevent soil erosion. Soil physicochemical properties and climatic characteristics most strongly associated to the AMF community composition included pH, textural components and nutrient contents of soil, and average evapotranspiration, rainfall and minimum temperature of the sampled locations. Pyrosequencing analysis revealed 33 AMF OTUs belonging to five families, with Archaeospora spp., Diversispora spp. and Paraglomus spp., being first records in olive. Interestingly, two of the most frequent OTUs included a diverse group of Claroideoglomeraceae and Glomeraceae sequences, not assigned to any known AMF species commonly used as inoculants in olive during nursery propagation. Conclusions/Significance Our data suggests that AMF can exert higher host specificity in olive than previously thought, which may have important implications for redirecting the olive nursery process in the future as well as to take into consideration the specific soils and environments where the mycorrhized olive trees will be established. PMID:24797669

Environmental fate of two sulfonamide antimicrobial agents in soil.

PubMed

Accinelli, Cesare; Koskinen, William C; Becker, Joanna M; Sadowsky, Michael J

2007-04-04

Veterinary antimicrobial agents have been detected in a number of environmental samples, including agricultural soils. In this study, we investigated the persistence and sorption of the sulfonamides sulfamethazine (SMZ) and sulfachloropyridine (SCP) in soil and their potential effects on soil microorganisms. The sulfonamides dissipated more rapidly from the silt loam soil as compared to the sandy soil. Average half-lives of SMZ and SPC among the two soils were 18.6 and 21.3 days, respectively. The presence of liquid swine slurry (5% v/w) decreased sulfonamide persistence in the silt loam soil. The lower persistence of the antimicrobials in liquid swine slurry-amended soil was likely due to higher microbial activity, as compared to unamended soil, and/or to the greater bioavailability of the sulfonamides to degrading microorganisms, as estimated by sorption isotherms. Concentrations of SMZ and SPC up to 100 microg g-1 had no effect on antimicrobial degradation rates and soil microorganisms. These studies suggest that higher sulfonamide concentrations would be necessary to affect the main processes controlling their environmental fates in soil, but at the concentrations normally found in the environment, there would be little or no effects.

40 CFR 264.231 - Special requirements for hazardous wastes FO20, FO21, FO22, FO23, FO26, and FO27.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Special requirements for hazardous wastes FO20, FO21, FO22, FO23, FO26, and FO27. 264.231 Section 264.231 Protection of Environment... chemical characteristics of the wastes, including their potential to migrate through soil or to volatilize...

(210)Pb as a tracer of soil erosion, sediment source area identification and particle transport in the terrestrial environment.

PubMed

Matisoff, Gerald

2014-12-01

Although (137)Cs has been used extensively to study soil erosion and particle transport in the terrestrial environment, there has been much less work using excess or unsupported (210)Pb ((210)Pbxs) to study the same processes. Furthermore, since (137)Cs activities in soils are decreasing because of radioactive decay, some locations have an added complication due to the addition of Chernobyl-derived (137)Cs, and the activities of (137)Cs in the southern hemisphere are low, there is a need to develop techniques that use (210)Pbxs to provide estimates of rates of soil erosion and particle transport. This paper reviews the current status of (210)Pbxs methods to quantify soil erosion rates, to identify and partition suspended sediment source areas, and to determine the transport rates of particles in the terrestrial landscape. Soil erosion rates determined using (210)Pbxs are based on the unsupported (210)Pb ((210)Pbxs) inventory in the soil, the depth distribution of (210)Pbxs, and a mass balance calibration ('conversion model') that relates the soil inventory to the erosion rate using a 'reference site' at which neither soil erosion nor soil deposition has occurred. In this paper several different models are presented to illustrate the effects of different model assumptions such as the timing, depth and rates of the surface soil mixing on the calculated erosion rates. The suitability of model assumptions, including estimates of the depositional flux of (210)Pbxs to the soil surface and the post-depositional mobility of (210)Pb are also discussed. (210)Pb can be used as one tracer to permit sediment source area identification. This sediment 'fingerprinting' has been extended far beyond using (210)Pb as a single radioisotope to include numerous radioactive and stable tracers and has been applied to identifying the source areas of suspended sediment based on underlying rock type, land use (roads, stream banks, channel beds, cultivated or uncultivated lands, pasture lands, forested lands, construction sites, undisturbed lands) or style of erosion (sheet wash, rills, bank). The transport time of particles in the terrestrial system can be estimated using (7)Be/(210)Pbxs radionuclide ratios and from mass balance models of (210)Pbxs and/or (7)Be in streams. Watershed residence times can be calculated from the radionuclide inventory and the erosional loss rate. Copyright © 2014 Elsevier Ltd. All rights reserved.

Prediction of Soil Erosion Rates in Japan where Heavily Forested Landscape with Unstable Terrain

NASA Astrophysics Data System (ADS)

Nanko, K.; Oguro, M.; Miura, S.; Masaki, T.

2016-12-01

Soil is fundamental for plant growth, water conservation, and sustainable forest management. Multidisciplinary interest in the role of the soil in areas such as biodiversity, ecosystem services, land degradation, and water security has been growing (Miura et al., 2015). Forest is usually protective land use from soil erosion because vegetation buffers rainfall power and erosivity. However, some types of forest in Japan show high susceptibility to soil erosion due to little ground cover and steep slopes exceeding thirty degree, especially young Japanese cypress (Chamaecyparis obtusa) plantations (Miura et al., 2002). This is a critical issue for sustainable forest management because C. obtusaplantations account for 10% of the total forest coverage in Japan (Forestry Agency, 2009). Prediction of soil erosion rates on nationwide scale is necessary to make decision for future forest management plan. To predict and map soil erosion rates across Japan, we applied three soil erosion models, RUSLE (Revised Universal Soil Loss Equation, Wischmeier and Smith, 1978), PESERA (Pan-European Soil Erosion Risk Assessment, Kirkby et al., 2003), and RMMF (Revised Morgan-Morgan-Finney, Morgan, 2001). The grid scale is 1-km. RUSLE and PESERA are most widely used erosion models today. RMMF includes interactions between rainfall and vegetation, such as canopy interception and ratio of canopy drainage in throughfall. Evaporated rainwater by canopy interception, generally accounts for 15-20% in annual rainfall, does not contribute soil erosion. Whereas, larger raindrops generated by canopy drainage produced higher splash erosion rates than gross rainfall (Nanko et al., 2008). Therefore, rainfall redistribution process in canopy should be considered to predict soil erosion rates in forested landscape. We compared the results from three erosion models and analyze the importance of environmental factors for the prediction of soil erosion rates. This research was supported by the Environment Research and Technology Development Fund (S15-2-2) of the Ministry of the Environment, Japan.

A geospatial soil-based DSS to reconcile landscape management and land protection

NASA Astrophysics Data System (ADS)

Manna, Piero; Basile, Angelo; Bonfante, Antonello; D'Antonio, Amedeo; De Michele, Carlo; Iamarino, Michela; Langella, Giuliano; Florindo Mileti, Antonio; Pileri, Paolo; Vingiani, Simona; Terribile, Fabio

2017-04-01

The implementation of UN Agenda 2030 may represent a great opportunity to place soil science at the hearth of many Sustainable Development Goals (e.g. SDGs 2, 3, 13, 15, 15.3, 16.7). On the other side the high complexity embedded in the factual implementation of SDG and many others ambitious objectives (e.g. FAO goals) may cause new frustrations if these policy documents will not bring real progresses. The scientific communities are asked to contribute to disentangle this complexity and possibly identifying a "way to go". This may help the large number of European directives (e.g. WFD, EIA), regulations and communications aiming to achieve a better environment but still facing large difficulties in their full implementation (e.g. COM2015/120; COM2013/683). This contribution has the motivation to provide a different perspective, thinking that the full implementation of SDGs and integrated land policies requires to challenge some key overlooked issues including full competence (and managing capability) about the landscape variability, its multi-functionalities (e.g. agriculture / environment) and its dynamic nature (many processes, including crops growth and fate of pollutants, are dynamic); moreover, it requires to support actions at a very detailed local scale since many processes and problems are site specific. The landscape and all the above issues have the soil as pulsing heart. Accordingly, we aim to demonstrate the multiple benefits in using a smart geoSpatial Decision Support System (S-DSS) grounded on soil modelling, called SOILCONSWEB (EU LIFE+ project and its extensions). It is a freely-accessible web platform based on a Geospatial Cyber-Infrastructure (GCI) and developed in Valle Telesina (South Italy) over an area of 20,000 ha. It supports a multilevel decision-making in agriculture and environment including the interaction with other land uses (such as landscape and urban planning) and thus it simultaneously delivers to SDGs 2, 3, 13, 15, 15.3, 16.7.

The MSP 2001 Mars Environmental Compatibility Assessment (MECA)

NASA Technical Reports Server (NTRS)

Hecht, M. H.; Meloy, T. P.; Anderson, M. S.; Buehler, M. G.; Frant, M. A.; Grannan, S. M.; Fuerstenau, D.; Keller, H. U.; Markiewicz, W. J.; Marshall, J.

1999-01-01

The Mars Environmental Compatibility Assessment (MECA) will evaluate the Martian environment for soil and dust-related hazards to human exploration as part of the Mars Surveyor Program 2001 Lander. Sponsored by the Human Exploration and Development of Space (HEDS) enterprise, MECA's goal is to evaluate potential geochemical and environmental hazards that may confront future Martian explorers, and to guide HEDS scientists in the development of high fidelity Mars soil simulants. The integrated MECA payload contains a wet-chemistry laboratory, a microscopy station, an electrometer to characterize the electrostatics of the soil and its environment, and arrays of material patches to study the abrasive and adhesive properties of soil grains. The instrument will acquire soil samples with a robotic arm equipped with a camera. MECA will examine surface and subsurface soil and dust in order to characterize particle size, shape, hardness, and also physical characteristics that may provide clues to mineralogy. MECA will characterize soil/water mixtures with respect to pH, redox potential, total dissolved ions, and trace toxins. MECA will determine the nature of electrostatic charging associated with excavation of soil, and the influence of ionizing radiation on material properties. It will also observe natural dust accumulation on engineering materials. To accomplish these objectives, MECA is allocated a mass of 10 kg within an enclosure of 35 x 25 x 15 cm. The Wet Chemistry Laboratory (WCL) consists of four identical cells that will accept samples from surface and subsurface regions accessible to the Lander's robotic arm, mix them with water, and perform extensive analysis of the solution. Ion-selective electrodes and related sensors will evaluate total dissolved solids, redox potential, pH, and the concentration of many soluble ions and gases in wet Martian soil. These electrodes can detect potentially dangerous heavy-metal ions, emitted pathogenic gases, and the soil's corrosive potential. Experiments will include cyclic voltammetry and anodic stripping voltammetry. Complementary to the Viking experiments, the chemical laboratory will characterize the water-soil solution rather than emitted gases. Nonetheless, through analysis of dissolved gases it will be able to replicate many of the Viking observations related to oxidants. MECA's microscopy station combines optical and atomic-force microscopy (AFM) in an actively focused, controlled illumination environment to image particles from millimeters to nanometers in size. Careful selection of substrates allows controlled experiments in adhesion, abrasion, hardness, aggregation, magnetic and other properties. Special tools allow primitive manipulation (brushing and scraping) of samples. Soil particle properties including size, shape, color, hardness, adhesive potential (electrostatic and magnetic), will be determined using an array of sample receptacles and collection substrates. The simple, rugged atomic-force microscope will image in the submicron size range and has the capability of performing a particle-by-particle analysis of the dust and soil. On Earth, the earliest forms of life are preserved as microfossils. The atomic-force microscope will have the required resolution to image down to the scale of terrestrial microfossils and beyond. Mounted on the end of the robot arm, MECA's electrometer actually consists of four types of sensors: an electric field meter, several triboelectricity monitors, an ion gauge, and a thermometer. Tempered only by ultraviolet-light-induced ions and a low-voltage breakdown threshold, the dry, cold, dusty martian environment presents an imposing electrostatic hazard to both robots and humans. The field meter will measure the ambient field on nearby objects while the triboelectric sensors, using identical circuitry, will measure the charge accumulated on test substances as they are dragged through the soil by the arm. The ion chamber, open to the environment, will sense both charged dust and free ions in the air. Over and above the potential threat to electronics, the electrostatic environment holds one of the keys to transport of dust and, consequently, Martian meteorology. Viewed with the robot arm camera, the abrasion and adhesion plates are strategically placed to allow direct observation of the interaction between materials and soils on a macroscopic scale. Materials of graded hardness are placed directly under the robot arm scoop to sense wear and soil hardness. A second array, placed on the lander deck, is deployed after the dust plume of landing has settled. It can be manipulated in a primitive fashion by the arm, first having dirt deposited on it from the scoop and subsequently shaken clean. A third array will passively collect dust from the atmosphere. In addition to objectives related to human exploration, the MECA data set will be rich in information relevant to basic geology, paleoclimate, and exobiology issues. To understand both contemporaneous and ancient processes on Mars, the mineralogy, petrology, and reactivity of Martian surface materials should be constrained. The MECA experiment will shed light on these quantities through its combination of chemistry and microscopy. MECA will be capable of measuring the composition of ancient surface water environments, observing microscopic evidence of geological (and biological?) processes, inferring soil and dust transport, comminution and weathering mechanisms, and characterizing soil horizons that might be encountered during excavation.

Soil Analysis Micro-Mission Concepts Derived from the MSP 2001 Mars Environmental Compatibility Assessment (MECA)

NASA Technical Reports Server (NTRS)

Hecht, M. H.; Meloy, T. P.; Anderson, M. S.; Buehler, M. G.; Frant, M. A.; Grannan, S. M.; Fuerstenau, S. D.; Keller, H. U.; Markiewicz, W. J.; Marshall, J.

1999-01-01

The Mars Environmental Compatibility Assessment (MECA) will evaluate the Martian environment for soil and dust-related hazards to human exploration as part of the Mars Surveyor Program 2001 Lander. The integrated MECA payload contains a wet-chemistry laboratory, a microscopy station, an electrometer to characterize the electrostatic environment, and arrays of material patches to study abrasion and adhesion. Heritage will be all-important for low cost micro-missions, and adaptations of instruments developed for the Pathfinder, '98 and '01 Landers should be strong contenders for '03 flights. This talk has three objectives: (1) Familiarize the audience with MECA instrument capabilities; (2) present concepts for stand-alone and/or mobile versions of MECA instruments; and (3) broaden the context of the MECA instruments from human exploration to a comprehensive scientific survey of Mars. Due to time limitations, emphasis will be on the chemistry and microscopy experiments. Ion-selective electrodes and related sensors in MECA's wet-chemistry laboratory will evaluate total dissolved solids, redox potential, pH, and the concentration of many soluble ions and gases in wet Martian soil. These electrodes can detect potentially dangerous heavy-metal ions, emitted pathogenic gases, and the soil's corrosive potential, and experiments will include cyclic voltammetry and anodic stripping. For experiments beyond 2001, enhancements could allow multiple use of the cells (for mobile experiments) and reagent addition (for quantitative mineralogical and exobiological analysis). MECA's microscopy station combines optical and atomic-force microscopy (AFM) in an actively focused, controlled illumination environment to image particles from millimeters to nanometers in size. Careful selection of substrates allows controlled experiments in adhesion, abrasion, hardness, aggregation, magnetic and other properties. Special tools allow primitive manipulation (brushing and scraping) of samples. Soil particle properties including size, shape, color, hardness, adhesive potential (electrostatic and magnetic), will be determined using an array of sample receptacles and collection substrates. The simple, rugged atomic-force microscope will image in the submicron size range and has the capability of performing a particle-by-particle analysis of the dust and soil. Future implementations might enhance the optical microscopy with spectroscopy, or incorporate advanced AFM techniques for thermogravimetric and chemical analysis.

Effects of cadmium and mycorrhizal fungi on growth, fitness, and cadmium accumulation in flax (Linum usitatissimum; Linaceae).

PubMed

Hancock, Laura M S; Ernst, Charlotte L; Charneskie, Rebecca; Ruane, Lauren G

2012-09-01

Agricultural soils have become contaminated with a variety of heavy metals, including cadmium. The degree to which soil contaminants affect plants may depend on symbiotic relationships between plant roots and soil microorganisms. We examined (1) whether mycorrhizal fungi counteract the potentially negative effects of cadmium on the growth and fitness of flax (Linum usitatissimum) and (2) whether mycorrhizal fungi affect the accumulation of cadmium within plant parts. Two flax cultivars (Linott and Omega) were grown in three soil cadmium environments (0, 5, and 15 ppm). Within each cadmium environment, plants were grown in either the presence or absence of mycorrhizal fungi. Upon senescence, we measured growth and fitness and quantified the concentration of cadmium within plants. Soil cadmium significantly decreased plant fitness, but did not affect plant growth. Mycorrhizal fungi, which were able to colonize roots of plants growing in all cadmium levels, significantly increased plant growth and fitness. Although mycorrhizal fungi counteracted the negative effects of cadmium on fruit and seed production, they also enhanced the concentration of cadmium within roots, fruits, and seeds. The degree to which soil cadmium affects plant fitness and the accumulation of cadmium within plants depended on the ability of plants to form symbiotic relationships with mycorrhizal fungi. The use of mycorrhizal fungi in contaminated agricultural soils may offset the negative effects of metals on the quantity of seeds produced, but exacerbate the accumulation of these metals in our food supply.

Ecophysiological responses of young mangrove species Rhizophora apiculata (Blume) to different chromium contaminated environments.

PubMed

Nguyen, Kim Linh; Nguyen, Hoang Anh; Richter, Otto; Pham, Minh Thinh; Nguyen, Van Phuoc

2017-01-01

Many mangrove forests have suffered from the contaminated environments near industrial areas. This study addresses the question how these environments influence the renewal of mangrove forests. To this end ecophysiological responses of the young mangrove species Rhizophora apiculata (Blume) grown under combinations of the factors heavy metals (here chromium), nutrition and soil/water environment were analyzed. We tested the hypothesis that soil/water conditions and nutrient status of the soil strongly influence the toxic effect of chromium. Seedlings of R. apiculata were grown in three different soil/water environments (natural saline soil with brackish water, salt-leached soil with fresh water and salt-leached-sterilized soil with fresh water) treated with different levels of chromium and NPK fertilizer. The system was inundated twice a day as similar to natural tidal condition in the mangrove wetland in the south of Vietnam. The experiments were carried out for 6months. Growth data of root, leaf and stem, root cell number and stomata number were recorded and analyzed. Results showed that growth of R. apiculata is slower in natural saline soil/water condition. The effect of chromium and of nutrients respectively depends on the soil/water condition. Under high concentrations of chromium, NPK fertilizer amplifies the toxic effect of chromium. Stomata density increases under chromium stress and is largest under the combination of chromium and salty soil/water condition. From the data a nonlinear multivariate regression model was derived capturing the toxicity threshold of R. apiculata under different treatment combinations. Copyright © 2016 Elsevier B.V. All rights reserved.

Long-term assessment of natural attenuation: statistical approach on soils with aged PAH contamination.

PubMed

Ouvrard, Stéphanie; Chenot, Elodie-Denise; Masfaraud, Jean-François; Schwartz, Christophe

2013-07-01

Natural attenuation processes valorization for PAH-contaminated soil remediation has gained increasing interest from site owners. A misunderstanding of this method and a small amount of data available does not encourage its development. However, monitored natural attenuation (MNA) offers a valuable, cheaper and environmentally friendly alternative to more classical options such as physico-chemical treatments (e.g., chemical oxidation, thermal desorption). The present work proposes the results obtained during a long-term natural attenuation assessment of historically contaminated industrial soils under real climatic conditions. This study was performed after a 10 year natural attenuation period on 60 off-ground lysimeters filled with contaminated soils from different former industrial sites (coking industry, manufactured gas plants) whose initial concentration of PAH varied between 380 and 2,077 mg kg(-1). The analysed parameters included leached water characterization, soil PAH concentrations, evaluation of vegetation cover quality and quantity. Results showed a good efficiency of the PAH dissipation and limited transfer of contaminants to the environment. It also highlighted the importance of the fine soil fractions in controlling PAH reactivity. PAH dissipation through water leaching was limited and did not present a significant risk for the environment. This PAH water concentration appeared however as a good indicator of overall dissipation rate, thereby illustrating the importance of pollutant availability in predicting its degradation potential.

METHODS FOR THE DETERMINATION OF TOTAL ORGANIC ...

EPA Pesticide Factsheets

Organic matter in soils and sediments is widely distributed over the earth's surface occurring in almost all terrestrial and aquatic environments (Schnitzer, 1978). Soils and sediments contain a large variety of organic materials ranging from simple sugars and carbohydrates to the more complex proteins, fats, waxes, and organic acids. Important characteristics of the organic matter include their ability to: form water-soluble and water- insoluble complexes with metal ions and hydrous oxides; interact with clay minerals and bind particles together; sorb and desorb both naturally-occurring and anthropogenically-introduced organic compounds; absorb and release plant nutrients; and hold water in the soil environment. As a result of these characteristics, the determination of total organic carbon (a measure of one of the chemical components of organic matter that is often used as an indicator of its presence in a soil or sediment) is an essential part of any site characterization since its presence or absence can markedly influence how chemicals will react in the soil or sediment. Soil and sediment total organic carbon (TOC) determinations are typically requested with contaminant analyses as part of an ecological risk assessment data package. TOC contents may be used qualitatively to assess the nature of the sampling location (e.g., was it a depositional area) or may be used to normalize portions of the analytical chemistry data set (e.g., equilibrium partitioning).

Soils as records of past and present environments

NASA Astrophysics Data System (ADS)

Sauer, Daniela

2015-04-01

This contribution reflects selected pedological concepts that are helpful for interpreting soil properties related to past and present environments. These concepts are illustrated by examples from various landscapes, and their combination finally leads to some further conclusions. The concept of Targulian and Gerasimova (2009) distinguishes soil system and soil body. Soil system is defined as "open multiphase system functioning in any solid-phase substrate at its interface with the atmosphere, hydrosphere and biota", and soil body as "solid-phase part of a soil system produced by its long-term functioning and composed of a vertical sequence of genetic horizons". Soil system functioning corresponds to the recent environmental factors and includes heat and moisture dynamics, biomass production, biogeochemical cycles, and other processes. In contrast, a soil body is a record of the long-term functioning of a soil system. It thus provides a record not only of the functioning of the soil system under the present environmental conditions but also under past, possibly different, conditions. Hence, Targulian and Goryachkin (2004) called it the "memory" of the landscape. Richter and Yaalon (2012) argued that most soils comprise both, features that developed under the present environmental conditions and features that reflect different conditions that the soils experienced in the past; they concluded that most soils are polygenetic. Although the current functioning of the soil system in the concept of Targulian and Gerasimova (2009) is mainly controlled by the present-day combination of environmental factors, it should be added that past processes also influence the soil system, because past processes changed the soil properties in a way that also the present-day functioning of the soil system is affected by these changes. Earlier, Yaalon (1971) had categorised soil properties according to the time-span required for their adjustment to the actual environment, distinguishing (i) rapidly adjusting soil properties (adjusting within some hundreds of years), (ii) slowly adjusting soil properties (adjusting within some thousands of years), and (iii) persistent soil properties (showing no changes over ten thousands to millions of years). In a polygenetic soil, rapidly adjusting soil properties may already be in equilibrium with the present conditions, whereas slowly adjusting soil properties may still reflect past conditions. Thus, the lower the rate at which a certain soil property in a polygenetic soil adjusts, the larger is the extent to which this property is still determined by earlier environmental conditions. Knowledge on the rates at which soil properties adjust may hence be used to estimate the time at which a significant environmental change took place, based on the degree of overprinting of the different kinds of soil properties adjusting at different rates in a polygenetic soil. References: Richter, D. de B., Yaalon, D.H., 2012. "The changing model of soil" revisited. Soil Sci. Soc. Am. J. 76, 766-778. Targulian, V. O., Goryachkin, S. V., 2004. Soil memory: Types of records, carriers, hierarchy and diversity. Revista Mexicana Ciencias Geol. 21, 1-8. Targulian, V.O., Gerasimova, M., 2009. Soil geography: geography of soil systems and soil bodies. Soil Geography: New Horizons. International Conference, 16-20 November 2009 in Huatulco, Mexico. Book of abstracts, 39. Yaalon, D.H., 1971. Soil forming processes in time and space. In: Yaalon, D.H. (Ed.), Paleopedology-origin, nature and dating of paleosols. Int. Soc. Soil Sci. and Israel Univ. Press, Jerusalem, pp. 29-39.

Use of treated wastewater in agriculture: effects on soil environment

NASA Astrophysics Data System (ADS)

Levy, Guy J.; Lado, Marcos

2014-05-01

Disposal of treated sewage, both from industrial and domestic origin (herein referred to as treated wastewater [TWW]), is often considered as an environmental hazard. However, in areas afflicted by water scarcity, especially in semi-arid and arid regions, where the future of irrigated agriculture (which produces approximately one third of crop yield and half the return from global crop production) is threatened by existing or expected shortage of fresh water, the use of TWW offers a highly effective and sustainable strategy to exploit a water resource. However, application of TWW to the soil is not free of risks both to organisms (e.g., crops, microbiota) and to the soil. Potential risks may include reduction in biological activity (including crop yield) due to elevated salinity and specific ion toxicity, migration of pollutants towards surface- and ground-water, and deterioration of soil structure. In recent years, new evidence about the possible negative impact of long-term irrigation with TWW on soil structure and physical and chemo-physical properties has emerged, thus putting the sustainability of irrigation with TWW in question. In this presentation, some aspects of the effects of long-term irrigation with TWW on soil properties are shown.

Agriculture on Mars: Soils for Plant Growth

NASA Technical Reports Server (NTRS)

Ming, D. W.

2016-01-01

Robotic rovers and landers have enabled the mineralogical, chemical, and physical characterization of loose, unconsolidated materials on the surface of Mars. Planetary scientists refer to the regolith material as "soil." NASA is currently planning to send humans to Mars in the mid 2030s. Early missions may rely on the use of onsite resources to enable exploration and self-sufficient outposts on Mars. The martian "soil" and surface environment contain all essential plant growth elements. The study of martian surface materials and how they might react as agricultural soils opens a new frontier for researchers in the soil science community. Other potential applications for surface "soils" include (i) sources for extraction of essential plant-growth nutrients, (ii) sources of O2, H2, CO2, and H2O, (iii) substrates for microbial populations in the degradation of wastes, and (iv) shielding materials surrounding outpost structures to protect humans, plants, and microorganisms from radiation. There are many challenges that will have to be addressed by soil scientists prior to human exploration over the next two decades.

Polynuclear aromatic hydrocarbons in the United Kingdom environment: a preliminary source inventory and budget.

PubMed

Wild, S R; Jones, K C

1995-01-01

This paper presents the first attempt to quantify the production, cycling, storage and loss of PAHs in the UK environment. Over 53 000 tonnes of sigmaPAHs (sum of 12 individual compounds) are estimated to reside in the contemporary UK environment, with soil being the major repository. If soils at contaminated sites are included, this estimate increases dramatically. Emission of PAHs to the UK atmosphere from primary combustion sources are estimated to be greater than 1000 tonnes sigmaPAHs per annum, with over 95% coming from domestic coal combustion, unregulated fires and vehicle emissions. It is estimated that approximately 210 tonnes of sigmaPAH are delivered to terrestrial surfaces each year via atmospheric deposition. Therefore, inputs of PAHs to the UK atmosphere outweigh the outputs by a factor of over 4. This may be explained by enhanced particulate deposition near point sources, PAH degradation in the atmosphere and transport away from the UK with prevailing winds. Disposal of waste residues is estimated to contribute a further 1000 tonnes of sigmaPAH per year to the terrestrial environment. It is illustrated that the use of creosote has the potential to release considerable quantities of PAHs to the UK environment. Temporal trends in PAH cycling are then considered. There is good evidence to suggest that air concentrations and fluxes to the UK surface are now lower than at any time throughout this century. Nonetheless, the UK sigmaPAH burden is still increasing at the present time, principally through retention by soils. However, there are marked differences in the behaviour of individual compounds: there is evidence, for example, that phenanthrene concentrations in soils have declined since the 1960s, although soil concentrations of benzo[a]pyrene and other heavier PAHs have continued to increase through this century. Volatilisation of low molecular weight PAHs accumulated in soils over previous decades may be making an important contribution to the current atmospheric burden. The major uncertainties identified by data on this budget are: (1) the lack of PAH concentrations in some environmental matrices; (2) the possible importance of contaminated soils as a major repository and source of PAHs; (3) the lack of emission data (especially vapour phase releases) for some PAH sources; (4) the importance of biodegradation and volatilisation as loss mechanisms for low molecular weight PAHs in soils; and (5) the importance of creosote use in the PAH cycle.

Sustainability of rare earth elements chain: from production to food - a review.

PubMed

Turra, Christian

2018-02-01

Rare earth elements (REE) are a group of chemical elements that include lanthanoids (lanthanum to lutetium), scandium and yttrium. In the last decades, the REE demand in the industry and other areas has increased significantly. In general, REE have shown low concentrations in soils, plants, water and atmosphere, but they may accumulate in such environments due to anthropogenic inputs. In areas where there is REE contamination, the slow accumulation of these elements in the environment could become problematic. Many studies have shown environmental areas contaminated with REE and their toxic effects. Thus, it is important to review, in order to improve the current understanding of these elements in the environment, showing the effects of REE exposure in mining, soil, water, plants and food. Besides, there are few suppliers and a limited quantity of these elements in the world. This paper suggests options to improve the sustainability management of REE chain.

Distribution of artificial sweeteners in dust and soil in China and their seasonal variations in the environment of Tianjin.

PubMed

Gan, Zhiwei; Sun, Hongwen; Yao, Yiming; Zhao, Yangyang; Li, Yan; Zhang, Yanwei; Hu, Hongwei; Wang, Ruonan

2014-08-01

A nationwide investigation on the occurrence of artificial sweeteners (ASs) was conducted by collecting 98 paired outdoor dust and soil samples from mainland China. The ASs were widely detected in Chinese atmospheric dry deposition and soil samples, at concentrations up to 6450 and 1280 ng/g, respectively. To give a picture on AS distribution and source in the whole environment, the concentrations and seasonal variations of ASs in Tianjin were studied, including atmosphere, soil, and water samples. The AS levels were significantly higher in Haihe river at TJW (a sampling site in central city) in winter, while no obviously seasonal trends were obtained at BYL (close to a AS factory) and the site at a wastewater treatment plant. Saccharin, cyclamate, and acesulfame were the dominant ASs in both gas and particulate phase, with concentrations varying from 0.02 to 1940 pg/m(3). Generally, gas phase concentrations of the ASs were relatively higher in summer, while opposite results were acquired for particulate phase. Wet and dry deposition fluxes were calculated based on the measured AS levels. The results indicated that both wet and dry deposition could efficiently remove ASs in the atmosphere and act as important pollutant sources for the ASs in surface environment. Copyright © 2014 Elsevier B.V. All rights reserved.

Sensitivity of Polygonum aviculare Seeds to Light as Affected by Soil Moisture Conditions

PubMed Central

Batlla, Diego; Nicoletta, Marcelo; Benech-Arnold, Roberto

2007-01-01

Background and Aims It has been hypothesized that soil moisture conditions could affect the dormancy status of buried weed seeds, and, consequently, their sensitivity to light stimuli. In this study, an investigation is made of the effect of different soil moisture conditions during cold-induced dormancy loss on changes in the sensitivity of Polygonum aviculare seeds to light. Methods Seeds buried in pots were stored under different constant and fluctuating soil moisture environments at dormancy-releasing temperatures. Seeds were exhumed at regular intervals during storage and were exposed to different light treatments. Changes in the germination response of seeds to light treatments during storage under the different moisture environments were compared in order to determine the effect of soil moisture on the sensitivity to light of P. aviculare seeds. Key Results Seed acquisition of low-fluence responses during dormancy release was not affected by either soil moisture fluctuations or different constant soil moisture contents. On the contrary, different soil moisture environments affected seed acquisition of very low fluence responses and the capacity of seeds to germinate in the dark. Conclusions The results indicate that under field conditions, the sensitivity to light of buried weed seeds could be affected by the soil moisture environment experienced during the dormancy release season, and this could affect their emergence pattern. PMID:17430979

The contribution of Japanese Soil Science Societies to scientific knowledge, education and sustainability: Good practices in the International Year of Soils 2015 towards the International Decade of Soils.

NASA Astrophysics Data System (ADS)

Kosaki, Takashi; Matoh, Toru; Inubushi, Kazuyuki; Sakurai, Katsutoshi

2017-04-01

The soil science community in Japan includes ca. 15,000 individuals from a variety of sectors, i.e. research, education, extension, business, national and local government, practitioners, non-governmental or non-profit organizations, etc., who have mostly (multi-)membership(s) in some of the academic societies. Among those societies, the Japanese Society of Soil Science and Plant Nutrition, the Japanese Society of Soil Microbiology and the Japanese Society of Pedology played a leading role in the promotion of the International Year of Soils 2015. The activities, many of which were jointly organized and executed by the above three, can be summarized as follows; Scientific symposiums/workshops not only within the societies but together with other disciplines such as geosciences, quaternary research, biogeochemistry, ecology, biosciences, geotechnology, etc. in national as well as international gatherings, Symposiums, (mobile) exhibitions, photo contests, science cafes, talk shows, field days, agricultural fairs, edutainment programs for school children, etc. for promoting the public awareness of soil and soil science, Publication of the books and booklets on the topics of soils, soil science, soil and environment (and/or food, life, human security, etc.), targeting the moderately educated public, Articles in selected newspapers, Distribution or sale of the novelty/memorial goods and items, e.g. soil globe, logo stickers, specially brewed Sake wines, etc. Translation of "Vienna Soil Declaration" of the IUSS into Japanese language and its distribution to the public, and Scientific and action proposal and its international dispatch of "The need to reinforce soil science research and the information basis to respond to both gradual and sudden changes in our environment" together with the Science Council of Japan. Scientific forums and gatherings as symposiums and workshops with other disciplines were successful and satisfied by most of the participants. Those for the general public were, however, not very much well known or widely accepted and thus were attended only by one to two hundred participants. Mobile exhibitions were well attended by the public and the educational programs out-of-doors for school children (with their parents) co-organized by a private (and environment conservation-oriented) company were very successful in terms of the promotion of the public awareness as well as CSR activities of a business firm. The TV stations paid a very little attention in broadcasting special and/or educational programs on soil and soil science. Based on the above experiences and evaluation, the societies are now planning next activities and actions aiming at the goals of the International Decade of Soils 2015-2024 and the UN SDGs till 2030.

Psychrotrophic Strain of Janthinobacterium lividum from a Cold Alaskan Soil Produces Prodigiosin

USDA-ARS?s Scientific Manuscript database

In the search for useful natural products such as enzymes and antibiotics, soil continues to be a fruitful environment. Combining culture-dependent and -independent approaches will accelerate discovery from environments as microbially complex as soil. Here we complement previous culture-independen...

Unique Organic Matter and Microbial Properties in the Rhizosphere of a Wetland Soil

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

Kaplan, Daniel I.; Xu, Chen; Huang, Shan

Wetlands attenuate the migration of many contaminants through a wide range of biogeochemical reactions. Recent research has shown that the rhizosphere, the zone near plant roots, in wetlands is especially effective at promoting contaminant attenuation. The objective of this study was to compare the soil organic matter (OM) composition and microbial communities of a rhizosphere soil (primarily an oxidized environment) to that of the bulk wetland soil (primarily a reduced environment). The rhizosphere had elevated C, N, Mn, and Fe concentrations and total bacteria, including Anaeromyxobacter, counts (as identified by qPCR). Furthermore, the rhizosphere contained several organic molecules that weremore » not identified in the nonrhizosphere soil (54% of the >2200 ESI-FTICR-MS identified compounds). The rhizosphere OM molecules generally had (1) greater overall molecular weights, (2) less aromaticity, (3) more carboxylate and N-containing COO functional groups, and (4) a greater hydrophilic character. These latter two OM properties typically promote metal binding. This study showed for the first time that not only the amount but also the molecular characteristics of OM in the rhizosphere may in part be responsible for the enhanced immobilization of contaminants in wetlands. These finding have implications on the stewardship and long-term management of contaminated wetlands« less

Risk of antibiotic resistance from metal contaminated soils

NASA Astrophysics Data System (ADS)

Knapp, Charles

2013-04-01

It is known that contaminated soils can lead to increased incidence of illness and disease, but it may also prevent our ability to fight disease. Many antibiotic resistant genes (ARG) acquired by bacteria originate from the environment. It is important to understand factors that influence levels of ARG in the environment, which could affect us clinically and agriculturally. The presence of elevated metal content in soils often promotes antibiotic resistance in exposed microorganisms. Using qPCR, the abundances of ARG to compare levels with geochemical conditions in randomly selected soils from several countries. Many ARG positively correlated with soil metal content, especially copper, chromium, nickel, lead, and iron. Results suggest that geochemical metal conditions influence the potential for antibiotic resistance in soil, which might be used to estimate baseline gene presence on various landscape scales and may translate to epidemiological risk of antibiotic-resistance transmission from the environment. This suggests that we may have to reconsider tolerances of metal pollution in the environment.

Effects of chemical elements in the trophic levels of natural salt marshes.

PubMed

Kamiński, Piotr; Barczak, Tadeusz; Bennewicz, Janina; Jerzak, Leszek; Bogdzińska, Maria; Aleksandrowicz, Oleg; Koim-Puchowska, Beata; Szady-Grad, Małgorzata; Klawe, Jacek J; Woźniak, Alina

2016-06-01

The relationships between the bioaccumulation of Na, K, Ca, Mg, Fe, Zn, Cu, Mn, Co, Cd, and Pb, acidity (pH), salinity (Ec), and organic matter content within trophic levels (water-soil-plants-invertebrates) were studied in saline environments in Poland. Environments included sodium manufactures, wastes utilization areas, dumping grounds, and agriculture cultivation, where disturbed Ca, Mg, and Fe exist and the impact of Cd and Pb is high. We found Zn, Cu, Mn, Co, and Cd accumulation in the leaves of plants and in invertebrates. Our aim was to determine the selectivity exhibited by soil for nutrients and heavy metals and to estimate whether it is important in elucidating how these metals are available for plant/animal uptake in addition to their mobility and stability within soils. We examined four ecological plant groups: trees, shrubs, minor green plants, and water macrophytes. Among invertebrates, we sampled breastplates Malacostraca, small arachnids Arachnida, diplopods Diplopoda, small insects Insecta, and snails Gastropoda. A higher level of chemical elements was found in saline polluted areas (sodium manufactures and anthropogenic sites). Soil acidity and salinity determined the bioaccumulation of free radicals in the trophic levels measured. A pH decrease caused Zn and Cd to increase in sodium manufactures and an increase in Ca, Zn, Cu, Cd, and Pb in the anthropogenic sites. pH increase also caused Na, Mg, and Fe to increase in sodium manufactures and an increase in Na, Fe, Mn, and Co in the anthropogenic sites. There was a significant correlation between these chemical elements and Ec in soils. We found significant relationships between pH and Ec, which were positive in saline areas of sodium manufactures and negative in the anthropogenic and control sites. These dependencies testify that the measurement of the selectivity of cations and their fluctuation in soils provide essential information on the affinity and binding strength in these environments. The chemical elements accumulated in soils and plants; however, further flow is selective and variable. The selectivity exhibited by soil systems for nutrients and heavy metals is important in elucidating how these metals become available for plant/animal uptake and also their mobility and stability in soils.

Interactions between earthworms and arsenic in the soil environment: a review.

PubMed

Langdon, Caroline J; Piearce, Trevor G; Meharg, Andrew A; Semple, Kirk T

2003-01-01

Chemical pollution of the environment has become a major source of concern. In particular, many studies have investigated the impact of pollution on biota in the environment. Studies on metalliferous contaminated mine spoil wastes have shown that some soil organisms have the capability to become resistant to metal/metalloid toxicity. Earthworms are known to inhabit arsenic-rich metalliferous soils and, due to their intimate contact with the soil, in both the solid and aqueous phases, are likely to accumulate contaminants present in mine spoil. Earthworms that inhabit metalliferous contaminated soils must have developed mechanisms of resistance to the toxins found in these soils. The mechanisms of resistance are not fully understood; they may involve physiological adaptation (acclimation) or be genetic. This review discusses the relationships between earthworms and arsenic-rich mine spoil wastes, looking critically at resistance and possible mechanisms of resistance, in relation to soil edaphic factors and possible trophic transfer routes.

Acid sulfate soils and human health--a Millennium Ecosystem Assessment.

PubMed

Ljung, Karin; Maley, Fiona; Cook, Angus; Weinstein, Philip

2009-11-01

Acid sulfate soils have been described as the "nastiest soils on earth" because of their strong acidity, increased mobility of potentially toxic elements and limited bioavailability of nutrients. They only cover a small area of the world's total problem soils, but often have significant adverse effects on agriculture, aquaculture and the environment on a local scale. Their location often coincides with high population density areas along the coasts of many developing countries. As a result, their negative impacts on ecosystems can have serious implications to those least equipped for coping with the low crop yields and reduced water quality that can result from acid sulfate soil disturbance. The Millennium Ecosystem Assessment called on by the United Nations in 2000 emphasised the importance of ecosystems for human health and well-being. These include the service they provide as sources of food and water, through the control of pollution and disease, as well as for the cultural services ecosystems provide. While the problems related to agriculture, aquaculture and the environment have been the focus of many acid sulfate soil management efforts, the connection to human health has largely been ignored. This paper presents the potential health issues of acid sulfate soils, in relation to the ecosystem services identified in the Millennium Ecosystem Assessment. It is recognised that significant implications on food security and livelihood can result, as well as on community cohesiveness and the spread of vector-borne disease. However, the connection between these outcomes and acid sulfate soils is often not obvious and it is therefore argued that the impact of such soils on human well-being needs to be recognised in order to raise awareness among the public and decision makers, to in turn facilitate proper management and avoid potential human ill-health.

Reconstruction of food webs in biological soil crusts using metabolomics.

NASA Astrophysics Data System (ADS)

Baran, Richard; Brodie, Eoin L.; Mayberry-Lewis, Jazmine; Nunes Da Rocha, Ulisses; Bowen, Benjamin P.; Karaoz, Ulas; Cadillo-Quiroz, Hinsby; Garcia-Pichel, Ferran; Northen, Trent R.

2015-04-01

Biological soil crusts (BSCs) are communities of organisms inhabiting the upper layer of soil in arid environments. BSCs persist in a dessicated dormant state for extended periods of time and experience pulsed periods of activity facilitated by infrequent rainfall. Microcoleus vaginatus, a non-diazotrophic filamentous cyanobacterium, is the key primary producer in BSCs in the Colorado Plateau and is an early pioneer in colonizing arid environments. Over decades, BSCs proceed through developmental stages with increasing complexity of constituent microorganisms and macroscopic properties. Metabolic interactions among BSC microorganisms probably play a key role in determining the community dynamics and cycling of carbon and nitrogen. However, these metabolic interactions have not been studied systematically. Towards this goal, exometabolomic analysis was performed using liquid chromatography coupled to tandem mass spectrometry on biological soil crust pore water and spent media of key soil bacterial isolates. Comparison of spent vs. fresh media was used to determine uptake or release of metabolites by specific microbes. To link pore water experiments with isolate studies, metabolite extracts of authentic soil were used as supplements for isolate exometabolomic profiling. Our soil metabolomics methods detected hundreds of metabolites from soils including many novel compounds. Overall, Microcoleus vaginatus was found to release and utilize a broad range of metabolites. Many of these metabolites were also taken up by heterotrophs but there were surprisingly few metabolites uptaken by all isolates. This points to a competition for a small set of central metabolites and specialization of individual heterotrophs towards a diverse pool of available organic nutrients. Overall, these data suggest that understanding the substrate specialization of biological soil crust bacteria can help link community structure to nutrient cycling.

You're never too young to play in the dirt!: Getting youth excited about soil

NASA Astrophysics Data System (ADS)

Anderson, Debbie; Davis, Jason; Driscoll, Liz; Hughes, Gail; Jones, Shelia; Kozlowski, Deborah; Liesch, Mandy; Lindbo, David L.; Weitzel, Sandra

2015-04-01

Teaching primary and secondary school students (K-12) about soils although absolutely critical, can be difficult. We have struggled with ways to bring soil science information to the larger audience as the direct approach meets with resistance due to the time commitments to other standards. One approach is to get students outside to see soils in their natural environment and relate soils to broader landscapes and land use issues. Field trips related to a specific class, including art classes, demonstrate to students the relation of soils to areas they would never have considered. After school and extracurricular programs such as 4-H, Girl and Boy Scouts can be designed to included soils demonstrations and with proper care get the students involve in the planning and implementation of a project that is related to agriculture (urban gardening) or landscaping to address runoff and erosion. Soils are an integral part of some science based team competitions as well. The Future Farmers and America Land Judging Contest is a prime example. In this competition students have to view a soil pit, connect it to the landscape and make recommendation for management. Envirothon, another science based team competition, relies less on field observations as part of the competition than Land Judging. Instead some of the instruction to prepare students has been done in the field to give the students a practical knowledge of soils. In order to enhance all these activities we have also develop a Mobile Soil Trailer that bring the needed equipment and demonstrations to teachers who may not access to all the necessary materials to teach soils in the field. The end result is getting students excited about soil so that when they go to college they may consider soils or related field as a career path.

ENVIRONMENTAL CHAMBER STUDIES OF MERCURY REACTIONS IN THE ATMOSPHERE

EPA Science Inventory

Mercury is released into the environment through both natural and anthropogenic pathways. The cycling and fate of mercury in atmospheric, soil, and water ecosystems is impacted by various factors, including chemical transformation and transport. An understanding of these proces...

Transformation of zinc-concentrate in surface and subsurface environments: Implications for assessing zinc mobility/toxicity and choosing an optimal remediation strategy.

PubMed

Kwon, Man Jae; Boyanov, Maxim I; Yang, Jung-Seok; Lee, Seunghak; Hwang, Yun Ho; Lee, Ju Yeon; Mishra, Bhoopesh; Kemner, Kenneth M

2017-07-01

Zinc contamination in near- and sub-surface environments is a serious threat to many ecosystems and to public health. Sufficient understanding of Zn speciation and transport mechanisms is therefore critical to evaluating its risk to the environment and to developing remediation strategies. The geochemical and mineralogical characteristics of contaminated soils in the vicinity of a Zn ore transportation route were thoroughly investigated using a variety of analytical techniques (sequential extraction, XRF, XRD, SEM, and XAFS). Imported Zn-concentrate (ZnS) was deposited in a receiving facility and dispersed over time to the surrounding roadside areas and rice-paddy soils. Subsequent physical and chemical weathering resulted in dispersal into the subsurface. The species identified in the contaminated areas included Zn-sulfide, Zn-carbonate, other O-coordinated Zn-minerals, and Zn species bound to Fe/Mn oxides or clays, as confirmed by XAFS spectroscopy and sequential extraction. The observed transformation from S-coordinated Zn to O-coordinated Zn associated with minerals suggests that this contaminant can change into more soluble and labile forms as a result of weathering. For the purpose of developing a soil washing remediation process, the contaminated samples were extracted with dilute acids. The extraction efficiency increased with the increase of O-coordinated Zn relative to S-coordinated Zn in the sediment. This study demonstrates that improved understanding of Zn speciation in contaminated soils is essential for well-informed decision making regarding metal mobility and toxicity, as well as for choosing an appropriate remediation strategy using soil washing. Copyright © 2017 Elsevier Ltd. All rights reserved.

Transformation of zinc-concentrate in surface and subsurface environments: Implications for assessing zinc mobility/toxicity and choosing an optimal remediation strategy

DOE PAGES

Kwon, Man Jae; Boyanov, Maxim I.; Yang, Jung -Seok; ...

2017-03-24

Zinc contamination in near- and sub-surface environments is a serious threat to many ecosystems and to public health. Sufficient understanding of Zn speciation and transport mechanisms is therefore critical to evaluating its risk to the environment and to developing remediation strategies. The geochemical and mineralogical characteristics of contaminated soils in the vicinity of a Zn ore transportation route were thoroughly investigated using a variety of analytical techniques (sequential extraction, XRF, XRD, SEM, and XAFS). Imported Zn-concentrate (ZnS) was deposited in a receiving facility and dispersed over time to the surrounding roadside areas and rice-paddy soils. Subsequent physical and chemical weatheringmore » resulted in dispersal into the subsurface. The species identified in the contaminated areas included Zn-sulfide, Zn-carbonate, other O-coordinated Zn-minerals, and Zn species bound to Fe/Mn oxides or clays, as confirmed by XAFS spectroscopy and sequential extraction. The observed transformation from S-coordinated Zn to O-coordinated Zn associated with minerals suggests that this contaminant can change into more soluble and labile forms as a result of weathering. For the purpose of developing a soil washing remediation process, the contaminated samples were extracted with dilute acids. The extraction efficiency increased with the increase of O-coordinated Zn relative to S-coordinated Zn in the sediment. Furthermore, this study demonstrates that improved understanding of Zn speciation in contaminated soils is essential for well-informed decision making regarding metal mobility and toxicity, as well as for choosing an appropriate remediation strategy using soil washing.« less

Developing ionic liquid forms of picloram with reduced negative effects on the aquatic environment.

PubMed

Tang, Gang; Wang, Baitao; Ding, Guanglong; Zhang, Wenbing; Liang, You; Fan, Chen; Dong, Hongqiang; Yang, Jiale; Kong, Dandan; Cao, Yongsong

2018-03-01

As a widely used herbicide, picloram has been frequently detected in the aquatic environment due to its high leaching potential and low adsorption by soil. To reduce aquatic environmental risk of this herbicide caused by leaching and runoff, five herbicidal ionic liquids (HILs) based on picloram were prepared by pairing isopropylamine, octylamine, octadecylamine, 1-methylimidazole, 4-methylmorpholine respectively. Their physicochemical properties including water solubility, octanol-water partition coefficient, surface activity, leaching, as well as soil adsorption were compared. The results showed that these properties could be adjusted by appropriate selection of counter cations. The HILs with long alkyl chains in cations had low water solubility and leaching characteristics, good surface tension and lipophilicity, as well as high soil adsorption. Compared with currently used picloram in the forms of potassium salts, HIL3 had more excellent herbicidal activity against broadleaf weeds and may offer a lower use dosage. The HILs based on picloram can reduce its negative effects on the aquatic environment and can be used as a desirable alternative to commercial herbicidal formulations of picloram in future. Copyright © 2017 Elsevier B.V. All rights reserved.

Particle Size Distribution of Heavy Metals and Magnetic Susceptibility in an Industrial Site.

PubMed

Ayoubi, Shamsollah; Soltani, Zeynab; Khademi, Hossein

2018-05-01

This study was conducted to explore the relationships between magnetic susceptibility and some soil heavy metals concentrations in various particle sizes in an industrial site, central Iran. Soils were partitioned into five fractions (< 28, 28-75, 75-150, 150-300, and 300-2000 µm). Heavy metals concentrations including Zn, Pb, Fe, Cu, Ni and Mn and magnetic susceptibility were determined in bulk soil samples and all fractions in 60 soil samples collected from the depth of 0-5 cm. The studied heavy metals except for Pb and Fe displayed a substantial enrichment in the < 28 µm. These two elements seemed to be independent of the selected size fractions. Magnetic minerals are specially linked with medium size fractions including 28-75, 75-150 and 150-300 µm. The highest correlations were found for < 28 µm and heavy metals followed by 150-300 µm fraction which are susceptible to wind erosion risk in an arid environment.

The environment of south-central Tunisia as observed on Landsat scene 206/036

USGS Publications Warehouse

Grolier, M.J.; Schultejann, P.A.

1982-01-01

One Landsat image in south-central Tunisia was analyzed to demonstrate the application of remote-sensing technology to regional development. A preliminary analysis included I) major landscape features; 2) gypsum-encrusted soils; and 3) phosphate-bearing beds exposed in the Gafsa mining district. The products specifically used for this report include: 1) A false-color composite (FCC), which had been linearly stretched to enhance contrast, and to which a modulation transfer function correction (a high-pass filter 3 pixels by 3 pixels wide) had been applied to enhance fine topographic relief. 2) A sinusoidally stretched false-color composite, on which mappable gypsum-encrusted soils and saline soils are detectable in greater detail than on the existing soil map of Tunisia at 1:500,000 scale. 3) A sinusoidally stretched band-ratio false-color composite, from which a thematic map of most phosphate-bearing beds in the Gafsa mining district was prepared. Recommendations for future Landsat image interpretation in Tunisia are offered.

Pesticide interactions with soil affected by olive mill wastewater (OMW): how strong and long-lasting is the OMW effect?

NASA Astrophysics Data System (ADS)

Keren, Yonatan; Borisover, Mikhail; Schaumann, Gabriele E.; Diehl, Dörte; Tamimi, Nisreen; Bukhanovsky, Nadezhda

2017-04-01

Sorption interactions with soils are well known to control the environmental fate of multiple organic compounds including pesticides. Pesticide-soil interactions may be affected by organic amendments or organic matter (OM)-containing wastewater brought to the field. Specifically, land spreading of olive mill wastewater (OMW), occurring intentionally or not, may also influence pesticide-soil interactions. The effects of the OMW disposed in the field on soil properties, including their ability to interact with pesticides, become of great interest due to the increasing demand for olive oil and a constant growth of world oil production. This paper summarizes some recent findings related to the effect of prior OMW land application on the ability of soils to interact with the organic compounds including pesticides, diuron and simazine. The major findings are as following: (1) bringing OMW to the field increases the potential of soils to sorb non-ionized pesticides; (2) this sorption increase may not be related solely to the increase in soil organic carbon content but it can reflect also the changes in the soil sorption mechanisms; (3) increased pesticide interactions with OMW-affected soils may become irreversible, due, assumedly, to the swelling of some components of the OMW-treated soil; (4) enhanced pesticide-soil interactions mitigate with the time passed after the OMW application, however, in the case of diuron, the remaining effect could be envisioned at least 600 days after the normal OMW application; (5) the enhancement effect of OMW application on soil sorption may increase with soil depth, in the 0-10 cm interval; (6) at higher pesticide (diuron) concentrations, larger extents of sorption enhancement, following the prior OMW-soil interactions, may be expected; (7) disposal of OMW in the field may be seasonal-dependent, and, in the case studied, it led to more distinct impacts on sorption when carried out in spring and winter, as compared with summer. It appears that when examining the fate of organic compounds in soil environments affected by OMW, more attention is needed to (a) the effect of the OMW penetration into the depth on soil-pesticide interactions; (b) long-term and seasonal-dependent effects of OMW application.

Chemical-biogeographic survey of secondary metabolism in soil.

PubMed

Charlop-Powers, Zachary; Owen, Jeremy G; Reddy, Boojala Vijay B; Ternei, Melinda A; Brady, Sean F

2014-03-11

In this study, we compare biosynthetic gene richness and diversity of 96 soil microbiomes from diverse environments found throughout the southwestern and northeastern regions of the United States. The 454-pyroseqencing of nonribosomal peptide adenylation (AD) and polyketide ketosynthase (KS) domain fragments amplified from these microbiomes provide a means to evaluate the variation of secondary metabolite biosynthetic diversity in different soil environments. Through soil composition and AD- and KS-amplicon richness analysis, we identify soil types with elevated biosynthetic potential. In general, arid soils show the richest observed biosynthetic diversity, whereas brackish sediments and pine forest soils show the least. By mapping individual environmental amplicon sequences to sequences derived from functionally characterized biosynthetic gene clusters, we identified conserved soil type-specific secondary metabolome enrichment patterns despite significant sample-to-sample sequence variation. These data are used to create chemical biogeographic distribution maps for biomedically valuable families of natural products in the environment that should prove useful for directing the discovery of bioactive natural products in the future.

Cd Mobility in Anoxic Fe-Mineral-Rich Environments - Potential Use of Fe(III)-Reducing Bacteria in Soil Remediation

NASA Astrophysics Data System (ADS)

Muehe, E. M.; Adaktylou, I. J.; Obst, M.; Schröder, C.; Behrens, S.; Hitchcock, A. P.; Tylsizczak, T.; Michel, F. M.; Krämer, U.; Kappler, A.

2014-12-01

Agricultural soils are increasingly burdened with heavy metals such as Cd from industrial sources and impure fertilizers. Metal contaminants enter the food chain via plant uptake from soil and negatively affect human and environmental health. New remediation approaches are needed to lower soil metal contents. To apply these remediation techniques successfully, it is necessary to understand how soil microbes and minerals interact with toxic metals. Here we show that microbial Fe(III) reduction initially mobilizes Cd before its immobilization under anoxic conditions. To study how microbial Fe(III) reduction influences Cd mobility, we isolated a new Cd-tolerant, Fe(III)-reducing Geobacter sp. from a heavily Cd-contaminated soil. In lab experiments, this Geobacter strain first mobilized Cd from Cd-loaded Fe(III) hydroxides followed by precipitation of Cd-bearing mineral phases. Using Mössbauer spectroscopy and scanning electron microscopy, the original and newly formed Cd-containing Fe(II) and Fe(III) mineral phases, including Cd-Fe-carbonates, Fe-phosphates and Fe-(oxyhydr)oxides, were identified and characterized. Using energy-dispersive X-ray spectroscopy and synchrotron-based scanning transmission X-ray microscopy, Cd was mapped in the Fe(II) mineral aggregates formed during microbial Fe(III) reduction. Microbial Fe(III) reduction mobilizes Cd prior to its precipitation in Cd-bearing mineral phases. The mobilized Cd could be taken up by phytoremediating plants, resulting in a net removal of Cd from contaminated sites. Alternatively, Cd precipitation could reduce Cd bioavailability in the environment, causing less toxic effects to crops and soil microbiota. However, the stability and thus bioavailability of these newly formed Fe-Cd mineral phases needs to be assessed thoroughly. Whether phytoremediation or immobilization of Cd in a mineral with reduced Cd bioavailability are feasible mechanisms to reduce toxic effects of Cd in the environment remains to be determined.

Chemical Characterization of the Degradation of Necromass from Four Ascomycota Fungi: Implications for Soil Organic Carbon Turnover and Storage

NASA Astrophysics Data System (ADS)

Bruner, V. J.; Schreiner, K. M.; Blair, N. E.; Egerton, L.

2016-12-01

Terrestrial soils store vast amounts of organic carbon, approximately twice as much carbon as is currently in the atmospheric CO2 pool. Despite its importance in the global carbon cycle, much is still unknown about the source, turnover, and stability of this soil organic carbon (SOC) pool. For example, fungi are known to play an important role in shaping the chemistry of SOC by degrading common biopolymers, and fungal biomass has been found to be a significant portion of living microbial SOC, dominating over bacteria in some soils by as much as 90%. And yet, despite growing evidence that microbial necromass may be larger contributors to SOC than previously thought, very little is known about the specific degradation patterns of fungal necromass and subsequently its potential chemical contributions to long-lived SOC pools. This study addresses these knowledge gaps through a time-series analysis of the degradation patterns of fungal tissue from four different saprotrophic Ascomyota species in temperate restored prairie soils. Fungal tissue was buried in soils both within a temperature- and light-controlled laboratory environment, and in a field environment, and harvested at intervals from 1 day to two months. After harvest, chemical analysis of the dried tissue by thermochemolysis pyrolysis-GCMS was used for relative quantitation of a variety of common biomolecules and biopolymers within the fungal tissue that may be long lived in soils, including chitin, glucan, mannan, ergosterol, and melanin. The degradation of these specific molecules, bulk fungal tissue, and bulk C and N within the tissue, is modeled to (1) show that a small portion of fungal necromass persists in the environment even after the period of the experiment and could serve as a contributor to long-lived SOC, and (2) provide quantitative information on the contribution of fungal tissue to global SOC pools.

Evaluating heavy metal accumulation and potential risks in soil-plant systems applied with magnesium slag-based fertilizer.

PubMed

Fan, Yuan; Li, Yongling; Li, Hua; Cheng, Fangqin

2018-04-01

Two typical Chinese soils including southern paddy soil and northern calcareous soils were used in a pot experiment to evaluate the effect of magnesium slag-based fertilizer on heavy metal accumulation and health risk in soil-plant system. The results indicated that magnesium slag-based fertilizer promoted the growth of maize plants. The concentrations of Cr, Cu, Pb and Zn in both soils amended with magnesium slag-based fertilizer were qualified for the second level criterion of Standard of Soil Environment (GB 15618-2009). Accumulation of HMs exhibited partitioning characteristics in maize plants, i.e. Cr and Cu were accumulated mainly in root and leaf parts while Pb was concentrated in roots. The order of transfer factors (TF) of HMs in different plant organs was ordered as follows: root > stem > leaf > grain. It indicated that less HMs were accumulated in the grain compared with that in other organs. The estimate daily intakes and total target hazard quotient of HMs including Cr, Cu, Pb, and Zn were less than 1, indicating that consumption of maize grain was at low risk and would not cause non-carcinogenic risks. From the above results, application of magnesium slag-based fertilizer at present level would not cause pollution risk for maize plants cultivated in two Chinese soils. Copyright © 2018. Published by Elsevier Ltd.

iTRAQ-based quantitative proteomic analysis of the earthworm Eisenia fetida response to Escherichia coli O157:H7.

PubMed

Wang, Xing; Li, Xiaoqin; Sun, Zhenjun

2018-05-21

Soil environment contaminated by Escherichia coli O157:H7 which come from the waste of infected animals. Earthworms can live in the pathogens-polluted soil by their innate immunity. How the proteins of earthworms E. fetida will response to E. coli O157:H7-contaminated-soil still unclear? To identify the defense proteins under E. coli O157:H7 stress, we performed a proteomic analysis of earthworm under E. coli O157:H7 exposure through an iTRAQ technology. In total, we found 283 non-redundant proteins, including fibrinolytic protease 1, lombricine kinase, lysozyme, gelsolin, coelomic cytolytic factor-1, antimicrobial peptide lumbricin-l, lysenin, and et al. The proteins participate in metabolic processes, transcription, defense response to bacterium, translation, response to stress, and transport. The study will contribute to understand why earthworm can live in the pathogens-polluted environment. Copyright © 2018 Elsevier Inc. All rights reserved.

Geochemistry, geomorphology, and soil petrology of the Mars-like soils from Pampas de la Joya hyper-arid desert

NASA Astrophysics Data System (ADS)

Valdivia-Silva, Julio E.; Ortega-Gutierrez, Fernando; Bonaccorsi, Rosalba

2016-07-01

Mars-like environments on Earth are used as a model to guide the investigation of possible habitable Martian environments. In this work we evaluate and analyze the geology, geomorphology and soil petrology of the Pampas de La Joya Desert in southern Peru, in order to understand the processes that transformed the region into a Mars-like environment. Using a multidisciplinary approach, we analyze the different soils that compose the floor of the desert, as well as describe and interpret the post-Oligocene landscape emphasizing some Mars-like features with respect to its acting geologic processes, the habitability potential under very low levels of nutrients and water, and its suitability to sustain microorganisms or their remains. Importantly, this work is part of a bigger project that use Mars-like soils, looking for new crops capable to grow in extreme environments.

Monitoring tropical environments with Space Shuttle photography

NASA Technical Reports Server (NTRS)

Helfert, Michael R.; Lulla, Kamlesh P.

1989-01-01

Orbital photography from the Space Shuttle missions (1981-88) and earlier manned spaceflight programs (1962-1975) allows remote sensing time series to be constructed for observations of environmental change in selected portions of the global tropics. Particular topics and regions include deforestation, soil erosion, supersedimentation in streams, lacustrine, and estuarine environments, and desertification in the greater Amazon, tropical Africa and Madagascar, South and Southeast Asia, and the Indo-Pacific archipelagoes.

Lightweight Exoatmospheric Projectile (LEAP) Test Program. Environment Assessment

DTIC Science & Technology

1991-07-01

and Man-Made Environment Kwajalein Atoll is a coral reef containing approximately 100 islands surrounding the largest lagoon in the Nlorld. The Atoll is...entirely from the remains of marine organisms such as reef corals , coralline algae, foramnifera, and others. Soils are coarse, grain size, alkaline...Kwajalein Atoll include ocean reefs , lagoon reefs , lagoon floor and sand flats, harbors, piers, quarries, and sea grass beds. Several reef species are

40 CFR 264.283 - Special requirements for hazardous wastes FO20, FO21, FO22, FO23, FO26, and FO27.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Special requirements for hazardous wastes FO20, FO21, FO22, FO23, FO26, and FO27. 264.283 Section 264.283 Protection of Environment... characteristics of the wastes, including their potential to migrate through soil or to volatilize or escape into...

40 CFR 264.317 - Special requirements for hazardous wastes FO20, FO21, FO22, FO23, FO26, and FO27.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Special requirements for hazardous wastes FO20, FO21, FO22, FO23, FO26, and FO27. 264.317 Section 264.317 Protection of Environment..., including their potential to migrate through the soil or to volatilize or escape into the atmosphere; (2...

Teaching About the Links Between Soils and Climate: An International Year of Soil Outreach by the Soil Science Society of America

NASA Astrophysics Data System (ADS)

Brevik, Eric C.

2015-04-01

Soil scientists are well aware of the intimate links that exist between soils and climate, but the same is not always true of the broader population. In an attempt to help address this, the Soil Science Society of America (SSSA) has designated the theme "Soils and Climate" for the month of November, 2015 as part of the SSSA International Year of Soil (IYS) celebration. The topic has been further subdivided into three subthemes: 1) carbon sequestration and greenhouse gases, 2) Soils and past environments, and 3) Desertification and drought. Each subtheme outreach has two parts 1) lesson plans that K-12 educators can use in their classrooms, and 2) materials that a trained soil scientist can present to the general public. Activities developed for the theme include classroom activities to accompany an online game that students can play to see how farm management choices influence greenhouse gas emissions, questions to go with a vermicomposting activity, and discussion session questions to go with a movie on the USA Dust Bowl. All materials are available online free of charge. The Soils and Climate materials can be found at https://www.soils.org/iys/12-month-resources/november; all of the SSSA IYS materials can be found at https://www.soils.org/iys.

Effects of the duration and inorganic nitrogen composition of a nutrient-rich patch on soil exploration by the roots of Lolium perenne in a heterogeneous environment.

PubMed

Nakamura, Ryoji; Kachi, N; Suzuki, J-I

2010-05-01

We investigated the growth of and soil exploration by Lolium perenne under a heterogeneous environment before its roots reached a nutrient-rich patch. Temporal changes in the distribution of inorganic nitrogen, i.e., NO(3)(-)-N and NH(4)(+)-N, in the heterogeneous environment during the experimental period were also examined. The results showed that roots randomly explored soil, irrespective of the patchy distribution of inorganic nitrogen and differences in the chemical composition of inorganic nitrogen distribution between heterogeneous and homogeneous environments. We have also elucidated the potential effects of patch duration and inorganic nitrogen distribution on soil exploration by roots and thus on plant growth.

Microbially supported phytoremediation of heavy metal contaminated soils: strategies and applications.

PubMed

Phieler, René; Voit, Annekatrin; Kothe, Erika

2014-01-01

Heavy metal contamination of soil as a result of, for example, mining operations, evokes worldwide concern. The use of selected metal-accumulating plants to clean up heavy metal contaminated sites represents a sustainable and inexpensive method for remediation approaches and, at the same time, avoids destruction of soil function. Within this scenario, phytoremediation is the use of plants (directly or indirectly) to reduce the risks of contaminants in soil to the environment and human health. Microbially assisted bioremediation strategies, such as phytoextraction or phytostabilization, may increase the beneficial aspects and can be viewed as potentially useful methods for application in remediation of low and heterogeneously contaminated soil. The plant-microbe interactions in phytoremediation strategies include mutually beneficial symbiotic associations such as mycorrhiza, plant growth promoting bacteria (PGPB), or endophytic bacteria that are discussed with respect to their impact on phytoremediation approaches.

Controls on the distribution of productivity and organic resources in Antarctic Dry Valley soils.

PubMed

Hopkins, D W; Sparrow, A D; Novis, P M; Gregorich, E G; Elberling, B; Greenfield, L G

2006-11-07

The Antarctic Dry Valleys are regarded as one of the harshest terrestrial habitats on Earth because of the extremely cold and dry conditions. Despite the extreme environment and scarcity of conspicuous primary producers, the soils contain organic carbon and heterotrophic micro-organisms and invertebrates. Potential sources of organic compounds to sustain soil organisms include in situ primary production by micro-organisms and mosses, spatial subsidies from lacustrine and marine-derived detritus, and temporal subsidies ('legacies') from ancient lake deposits. The contributions from these sources at different sites are likely to be influenced by local environmental conditions, especially soil moisture content, position in the landscape in relation to lake level oscillations and legacies from previous geomorphic processes. Here we review the abiotic factors that influence biological activity in Dry Valley soils and present a conceptual model that summarizes mechanisms leading to organic resources therein.

Factors Affecting the Distribution of Perfluorinated Compounds in Sediments from Lake Shihwa, Korea

EPA Science Inventory

Perfluorinated compounds (PFCs) are ubiquitously distributed in various environmental media including water, soil, sediment, and biota. PFCs have also been shown to biomagnify in both aquatic and terrestrial environments. Lake Shihwa is an artificial saltwater lake, located on ...

Mitigation of salt stress in white clover (Trifolium repens) by Azospirillum brasilense and its inoculation effect.

PubMed

Khalid, Muhammad; Bilal, Muhammad; Hassani, Danial; Iqbal, Hafiz M N; Wang, Hang; Huang, Danfeng

2017-12-01

Salinity is one of the increasingly serious environmental problems worldwide for cultivating agricultural crops. The present study was aimed to ascertain the potential of beneficial soil bacterium Azospirillum brasilense to alleviate saline stress in Trifolium repens. Experimental plants (white clover) were grown from seeds and inoculated with or without A. brasilense bacterial strain supplemented with 0, 40, 80, or 120 mM NaCl into soil. The growth attributes including, shoot heights, root lengths, fresh and dry weights, leaf area and chlorophyll content were significantly enhanced in T. repens plants grown in A. brasilense inoculated soil than un-inoculated controls, particularly under elevated salinity conditions (40, 80 and 120 mM NaCl). Malondialdehyde content of leaf was recorded to be declined under saline conditions. Moreover, the K + /Na + ratio was also improved in bacterium-inoculated plants, since A. brasilense significantly reduced the root and shoot Na + level under high salty environment. Results revealed that soil inoculation with A. brasilense could significantly promote T. repens growth under both non-saline and saline environments, and this study might be extended to other vegetables and crops for the germination and growth enhancement.

Comprehensive genomic and phenotypic metal resistance profile of Pseudomonas putida strain S13.1.2 isolated from a vineyard soil.

PubMed

Chong, Teik Min; Yin, Wai-Fong; Chen, Jian-Woon; Mondy, Samuel; Grandclément, Catherine; Faure, Denis; Dessaux, Yves; Chan, Kok-Gan

2016-12-01

Trace metals are required in many cellular processes in bacteria but also induce toxic effects to cells when present in excess. As such, various forms of adaptive responses towards extracellular trace metal ions are essential for the survival and fitness of bacteria in their environment. A soil Pseudomonas putida, strain S13.1.2 has been isolated from French vineyard soil samples, and shown to confer resistance to copper ions. Further investigation revealed a high capacity to tolerate elevated concentrations of various heavy metals including nickel, cobalt, cadmium, zinc and arsenic. The complete genome analysis was conducted using single-molecule real-time (SMRT) sequencing and the genome consisted in a single chromosome at the size of 6.6 Mb. Presence of operons and gene clusters such as cop, cus, czc, nik, and asc systems were detected and accounted for the observed resistance phenotypes. The unique features in terms of specificity and arrangements of some genetic determinants were also highlighted in the study. Our findings has provided insights into the adaptation of this strain to accumulation and persistence of copper and other heavy metals in vineyard soil environment.

Genesis and properties of wetland soils by VIS-NIR-SWIR as a technique for environmental monitoring.

PubMed

Demattê, José Alexandre Melo; Horák-Terra, Ingrid; Beirigo, Raphael Moreira; Terra, Fabrício da Silva; Marques, Karina Patrícia Prazeres; Fongaro, Caio Troula; Silva, Alexandre Christófaro; Vidal-Torrado, Pablo

2017-07-15

Wetlands are important ecosystems characterized by redoximorphic environments producing typical soil forming processes and organic carbon accumulation. Assessments and management of these areas are dependent on knowledge about soil characteristics and variability. By reflectance spectroscopy, information about soils can be obtained since their spectral behaviors are directly related to their chemical, physical, and mineralogical properties reflecting the pedogenetic processes and environment conditions. Our aims were: (a) to characterize the main soil classes of wetlands regarding their spectral behaviors in VIS-NIR-SWIR (350-2500 nm) and relate them to pedogenesis and environmental conditions, (b) to determine spectral ranges (bands) with greater expression of the main soil properties, (c) to identify spectral variations and similarities between hydromorphic soils from wetlands and other soils under different moisture conditions, and (d) to propose spectral models to quantify some chemical and physical soil properties used as environmental quality indicators. Nine soil profiles from the Pantanal region (Mato Grosso State, Brazil) and one from the Serra do Espinhaço Meridional (Minas Gerais State, Brazil) were investigated. Spectral morphology interpretation allowed identifying horizon differences regarding shape, absorption features and reflectance intensity. Some pedogenetic processes of wetland soils related to organic carbon accumulation and oxide iron variation were identified by spectra. Principal Component Analysis allowed discriminating soils from wetland and outside this area (oxidic environment). Quantification of organic carbon was possible with R 2 of 0.90 and low error. Quantification of clay content was masked by soils with organic carbon content over 2% where it was not possible to quantify with high R 2 and low error both properties when dataset has soil samples with high organic carbon content. By reflectance spectroscopy, important characteristics of wetland soils can be identified and used to distinguish from soils of different environments at low costs, reduced time, and with environmental quality. Copyright © 2017 Elsevier Ltd. All rights reserved.

SOIL BIOLOGY AND ECOLOGY

EPA Science Inventory

The term "Soil Biology", the study of organism groups living in soil, (plants, lichens, algae, moss, bacteria, fungi, protozoa, nematodes, and arthropods), predates "Soil Ecology", the study of interactions between soil organisms as mediated by the soil physical environment. oil ...

Quantifying the main sediment sources in agricultural landscapes of Southern Brazil cultivated with conventional and conservation practices

NASA Astrophysics Data System (ADS)

Evrard, Olivier; Le Gall, Marion; Tiecher, Tales; Gomes Minella, Jean Paolo; Laceby, J. Patrick; Ayrault, Sophie

2017-04-01

Agricultural expansion that occurred in the 1960s in Southern Brazil significantly increased soil erosion and sediment supply to the river networks. To limit the deleterious impacts of soil erosion, conservation practices were progressively implemented in the 1990s, including the direct sowing of crops on a soil densely covered with plant residues, contour farming, the installation of ponds to trap sediment in the landscape and the use of crop rotations. However, there remains a lack of observational data to investigate the impact of these conservation practices on soil erosion and sediment supply. This data is crucial to protect soil resources and maintain the sustainability of food production systems in this region of the world characterized by a rapidly increasing population. Accordingly, sediment sources were investigated in the Guaporé catchment (2,032 km2) representative of the cultivated environments found in this part of the world. In the upper catchment, the landscape is characterized by gentle slopes and deep soils (Ferralsols, Nitisols) corresponding to the edge of the basaltic plateau. Soybean, corn and wheat under direct sowing are the main crops in this area. In contrast, steep and shallow soils (Luvisols, Acrisols, Leptosols) highly connected to the rivers are found in the lower catchment, where tobacco and corn fields are cultivated with conventional ploughing. These soil types were characterized by elemental geochemistry and 87Sr/86Sr ratios. Sediment sources were then modelled using the optimal suite of properties (87Sr/86Sr ratios, K, Ti, Co, As, Ba, and Pb). The results demonstrate that sediment collected at the catchment outlet during two hydrological years (2012-2014) mainly originated from downstream soils (Luvisols, Acrisols, Leptosols; 92±3%), with this proportion remaining stable throughout the monitoring period. This research indicates that conservation practices implemented in the upper catchment are effective and that similar methods should be applied to downstream soils in order to conserve soil resources and limit the degradation of freshwater environments.

Radioisotope tracer approach for understanding the impacts of global change-induced pedoturbation on soil C dynamics

NASA Astrophysics Data System (ADS)

Gonzalez-Meler, M. A.; Sturchio, N. C.; Sanchez-de Leon, Y.; Blanc-Betes, E.; Taneva, L.; Poghosyan, A.; Norby, R. J.; Filley, T. R.; Guilderson, T. P.; Welker, J. M.

2010-12-01

Biogeochemical carbon-cycle feedbacks to climate are apparent but uncertain, primarily because of gaps in mechanistic understanding on the ecosystem processes that drive carbon cycling and storage in terrestrial ecosystems, particularly in soils. Recent findings are increasingly recognizing the interaction between soil biota and the soil physical environment. Soil carbon turnover is partly determined by burial of organic matter and its physical and chemical protection. These factors are potentially affected by changes in climate (freezing-thawing or wet-drying cycles) or ecosystem structure including biological invasions. A major impediment to understanding dynamics of soil C in terrestrial systems is our inability to measure soil physical processes such as soil mixing rates or turnover of soil structures, including aggregates. Here we present a multiple radioisotope tracer approach (naturally occurring and man-made) to measure soil mixing rates in response to global change. We will present evidence of soil mixing rate changes in a temperate forest exposed to increased levels of atmospheric CO2 and in a tundra ecosystem exposed to increased thermal insulation. In both cases, radioisotope tracers proved to be an effective way to measure effects of global change on pedoturbation. Results also provided insights into the specific mechanisms involved in the responses. Elevated CO2 resulted in deeper soil mixing cells (increased by about 5cm on average) when compared to control soils as a consequence of changes in biota (increased root growth, higher earthworm density). In the tundra, soil warming induced higher rates of cryoturbation, resulting in what appears to be a net uplift of organic matter to the surface thereby exposing deeper C to decomposers. In both cases, global change factors affected the vertical distribution of C and changed the amount of bulk soil actively involved in soil processes. As a consequence, comparisons of C budgets to a given soil depth in response to global change factors may be misleading if they do not account for the depth change in the soil mixing cells.

Bioabsorption and Bioaccumulation of Cadmium in the Straw and Grain of Maize (Zea mays L.) in Growing Soils Contaminated with Cadmium in Different Environment.

PubMed

Retamal-Salgado, Jorge; Hirzel, Juan; Walter, Ingrid; Matus, Iván

2017-11-16

There is a worldwide increase of heavy metal or potentially toxic element (PTE), contamination in agricultural soils caused mainly by human and industrial action, which leads to food contamination in crops such as in maize. Cadmium (Cd) is a PTE often found in soils and it is ingested through food. It is necessary to determine the bioabsorption, distribution, and accumulation levels in maize to reduce or prevent food chain contamination. Cadmium absorption and accumulation in three maize cultivars were evaluated in three agricultural environments in Chile by increasing CdCl₂ rates (0, 1, and 2 mg·kg -1 ). Evaluation included Cd accumulation and distribution in different plant tissues, bioaccumulation factor (BAF), bioconcentration factor (BCF), translocation factor (TF), and tolerance index (TI). Cadmium whole-plant uptake was only affected by the CdCl₂ rate; the highest uptake was obtained with 2 mg·kg -1 CdCl₂ (34.4 g·ha -1 ) ( p < 0.05). Cadmium distribution in the maize plant usually exhibited the highest accumulation in the straw ( p < 0.05), independently of the environment, Cd rate, and evaluated cultivar. Given the results for TF (TF > 2) and BAF (BAF > 1), the Los Tilos and Chillán environments were classified as having a high capacity to contaminate the food chain for all evaluated cultivars.

Diversity of Ktedonobacteria with Actinomycetes-Like Morphology in Terrestrial Environments

PubMed Central

Yabe, Shuhei; Sakai, Yasuteru; Abe, Keietsu; Yokota, Akira

2017-01-01

Bacteria with an actinomycetes-like morphology have recently been discovered, and the class Ktedonobacteria was created for these bacteria in the phylum Chloroflexi. They may prove to be a valuable resource with the potential to produce unprecedented secondary metabolites. However, our understanding of their diversity, richness, habitat, and ecological significance is very limited. We herein developed a 16S rRNA gene-targeted, Ktedonobacteria-specific primer and analyzed ktedonobacterial amplicons. We investigated abundance, diversity, and community structure in forest and garden soils, sand, bark, geothermal sediment, and compost. Forest soils had the highest diversity among the samples tested (1181–2934 operational taxonomic units [OTUs]; Chao 1 estimate, 2503–5613; Shannon index, 4.21–6.42). A phylogenetic analysis of representative OTUs revealed at least eight groups within unclassified Ktedonobacterales, expanding the known diversity of this order. Ktedonobacterial communities markedly varied among our samples. The common mesic environments (soil, sand, and bark) were dominated by diverse phylotypes within the eight groups. In contrast, compost and geothermal sediment samples were dominated by known ktedonobacterial families (Thermosporotrichaceae and Thermogemmatisporaceae, respectively). The relative abundance of Ktedonobacteria in the communities, based on universal primers, was ≤0.8%, but was 12.9% in the geothermal sediment. These results suggest that unknown diverse Ktedonobacteria inhabit common environments including forests, gardens, and sand at low abundances, as well as extreme environments such as geothermal areas. PMID:28321007

Soil Science Education for Primary and Secondary Students

NASA Astrophysics Data System (ADS)

Sparrow, Elena; Yoshikawa, Kenji; Kopplin, Martha

2013-04-01

Soils is one of the science investigation areas in the Global learning and Observations to Benefit the Environment (GLOBE), an international science and education program (112 countries) that teaches primary and secondary students to learn science by doing science. For each area of investigation GLOBE provides background information, measurement protocols and learning activities compiled as a chapter in the GLOBE Teacher's Guide. Also provided are data sheets and field guides to assist in the accurate collection of data as well as suggestions of scientific instruments and calibration methods. Teachers learn GLOBE scientific measurement protocols at professional development workshops led by scientists and educators, who then engage their students in soil studies that also contribute to ongoing science investigations. Students enter their data on the GLOBE website and can access their data as well as other data contributed by students from other parts of the world. Soil characterization measurements carried out in the field include site description, horizon depths, soil structure, soil color, soil consistence, soil texture, roots, rocks and carbonates. Other field measurements are soil temperature and soil moisture monitoring while the following measurements are carried out in the classroom or laboratory: gravimetric soil moisture, bulk density, particle density, particle size distribution, pH and soil fertility (nitrogen, phosphorus and potassium). Learning activities provide support for preparing students to do the measurements and for better understanding of science concepts. Many countries in GLOBE have adopted standards for education including science education with commonalities among them. For the Teacher's Guide, the National Science Education Standards published by the US National Academy of Sciences, selected additional content standards that GLOBE scientists and educators feel are appropriate and the National Geography Standards prepared by the (US) National Education Standards Project, are being used. Educational objectives for students include gaining scientific inquiry abilities in addition to understanding scientific concepts. The Soils chapter also includes some suggestions for managing students in the field and classroom. A new protocol has also been developed by the Seasons and Biomes project, one of the GLOBE earth system science projects. Active Layer monitoring uses a Frost Tube that measures when and how deeply soil freezes and is currently being used in more than 200 sites in Alaska. Teachers have successfully implemented soil studies in their curriculum and have used it to teach about the science process.

Mapping CO2 emission in highly urbanized region using standardized microbial respiration approach

NASA Astrophysics Data System (ADS)

Vasenev, V. I.; Stoorvogel, J. J.; Ananyeva, N. D.

2012-12-01

Urbanization is a major recent land-use change pathway. Land conversion to urban has a tremendous and still unclear effect on soil cover and functions. Urban soil can act as a carbon source, although its potential for CO2 emission is also very high. The main challenge in analysis and mapping soil organic carbon (SOC) in urban environment is its high spatial heterogeneity and temporal dynamics. The urban environment provides a number of specific features and processes that influence soil formation and functioning and results in a unique spatial variability of carbon stocks and fluxes at short distance. Soil sealing, functional zoning, settlement age and size are the predominant factors, distinguishing heterogeneity of urban soil carbon. The combination of these factors creates a great amount of contrast clusters with abrupt borders, which is very difficult to consider in regional assessment and mapping of SOC stocks and soil CO2 emission. Most of the existing approaches to measure CO2 emission in field conditions (eddy-covariance, soil chambers) are very sensitive to soil moisture and temperature conditions. They require long-term sampling set during the season in order to obtain relevant results. This makes them inapplicable for the analysis of CO2 emission spatial variability at the regional scale. Soil respiration (SR) measurement in standardized lab conditions enables to overcome this difficulty. SR is predominant outgoing carbon flux, including autotrophic respiration of plant roots and heterotrophic respiration of soil microorganisms. Microbiota is responsible for 50-80% of total soil carbon outflow. Microbial respiration (MR) approach provides an integral CO2 emission results, characterizing microbe CO2 production in optimal conditions and thus independent from initial difference in soil temperature and moisture. The current study aimed to combine digital soil mapping (DSM) techniques with standardized microbial respiration approach in order to analyse and map CO2 emission and its spatial variability in highly urbanized Moscow region. Moscow region with its variability of bioclimatic conditions and high urbanization level (10 % from the total area) was chosen as an interesting case study. Random soil sampling in different soil zones (4) and land-use types (3 non-urban and 3 urban) was organized in Moscow region in 2010-2011 (n=242). Both topsoil (0-10 cm) and subsoil (10-150 cm) were included. MR for each point was analysed using standardized microbial (basal) respiration approach, including the following stages: 1) air dried soil samples were moisturised up to 55% water content and preincubated (7 days, 22° C) in a plastic bag with air exchange; 2) soil MR (in μg CO2-C g-1) was measured as the rate of CO2 production (22° C, 24 h) after incubating 2g soil with 0.2 μl distilled water; 3) the MR results were used to estimate CO2 emission (kg C m-2 yr-1). Point MR and CO2 emission results obtained were extrapolated for the Moscow region area using regression model. As a result, two separate CO2 maps for topsoil and subsoil were created. High spatial variability was demonstrated especially for the urban areas. Thus standardized MR approach combined with DSM techniques provided a unique opportunity for spatial analysis of soil carbon temporal dynamics at the regional scale.

[Effect of environmental factors on bacterial community structure in petroleum contaminated soil of Karamay oil field].

PubMed

Liang, Jianfang; Yang, Jiangke; Yang, Yang; Chao, Qunfang; Yin, Yalan; Zhao, Yaguan

2016-08-04

This study aimed to study the phylogenetic diversity and community structure of bacteria in petroleum contaminated soils from Karamay oil field, and to analyze the relationship between the community variation and the environment parameters, to provide a reference for bioremediation of petroleum contaminated soils. We collected samples from petroleum contaminated soils in 5 cm, 20 cm and 50 cm depth layers, and measured the environment parameters subsequently. We constructed three 16S rRNA gene clone libraries of these soil samples, and then determined the operation taxonomy units (OTUs) restriction fragment length polymorphism method, and finally sequenced the representative clones of every OUT. The diversity, richness and evenness index of the bacteria communities were calculated by using Biodap software. Neighbor-Joining phylogenetic tree was constructed based on 16S rRNA gene sequences of bacteria from Karamay oil field and the references from related environments. Canonial correspondence analysis (CCA) was used to analyze the relationship between environment parameters and species by using CANOCO 4.5 software. Environment parameters showed that 50 cm deep soil contained the highest amount of total nitrogen (TN) and total phosphorus (TP), whereas the 20 cm depth soil contained the lowest amount. The 5 cm depth soil contained the highest amount of total organic carbon (TOC), whereas the 50 cm depth soil contained the lowest amount. Among the 3 layers, 20 cm depth had the highest diversity and richness of bacteria, whereas the bacteria in 50 cm depth was the lowest. Phylogenic analyses suggested that the bacteria in Karamay oil field could be distributed into five groups at the level of phylum, Cluster I to V, respectively belong to Proteobacteria, Actinobacteria, Firmicute, Bacteroidetes, Planctomycetes. Cluster I accounts for 78.57% of all tested communities. CCA results showed that TN, TP, TOC significantly affected the bacteria community structure. Especially, TOC content is significantly related to the distribution of Pseudomonas. The petroleum-contaminated soil inhabited abundant of bacteria. The diversity index and spatial distribution of these communities were affected by the environment parameters in the soil.

Influence of glutamic acid enantiomers on C-mineralization.

PubMed

Formánek, Pavel; Vranová, Valerie; Lojková, Lea

2015-02-01

Seasonal dynamics in the mineralization of glutamic acid enantiomers in soils from selected ecosystems was determined and subjected to a range of treatments: ambient x elevated CO2 level and meadow x dense x thinned forest environment. Mineralization of glutamic acid was determined by incubation of the soil with 2 mg L- or D-glutamic acid g(-1) of dry soil to induce the maximum respiration rate. Mineralization of glutamic acid enantiomers in soils fluctuates over the course of a vegetation season, following a similar trend across a range of ecosystems. Mineralization is affected by environmental changes and management practices, including elevated CO2 level and thinning intensity. L-glutamic acid metabolism is more dependent on soil type as compared to metabolism of its D-enantiomer. The results support the hypothesis that the slower rate of D- compared to L- amino acid mineralization is due to different roles in anabolism and catabolism of the soil microbial community. © 2014 Wiley Periodicals, Inc.

Screening and Characterization of Potentially Suppressive Soils against Gaeumannomyces graminis under Extensive Wheat Cropping by Chilean Indigenous Communities.

PubMed

Durán, Paola; Jorquera, Milko; Viscardi, Sharon; Carrion, Victor J; Mora, María de la Luz; Pozo, María J

2017-01-01

Wheat production around the world is severely compromised by the occurrence of "take-all" disease, which is caused by the soil-borne pathogen Gaeumannomyces graminis var. tritici (Ggt). In this context, suppressive soils are those environments in which plants comparatively suffer less soil-borne pathogen diseases than expected, owing to native soil microorganism activities. In southern Chile, where 85% of the national cereal production takes place, several studies have suggested the existence of suppressive soils under extensive wheat cropping. Thus, this study aimed to screen Ggt-suppressive soil occurrence in 16 locations managed by indigenous "Mapuche" communities, using extensive wheat cropping for more than 10 years. Ggt growth inhibition in vitro screenings allowed the identification of nine putative suppressive soils. Six of these soils, including Andisols and Ultisols, were confirmed to be suppressive, since they reduced take-all disease in wheat plants growing under greenhouse conditions. Suppressiveness was lost upon soil sterilization, and recovered by adding 1% of the natural soil, hence confirming that suppressiveness was closely associated to the soil microbiome community composition. Our results demonstrate that long-term extensive wheat cropping, established by small Mapuche communities, can generate suppressive soils that can be used as effective microorganism sources for take-all disease biocontrol. Accordingly, suppressive soil identification and characterization are key steps for the development of environmentally-friendly and efficient biotechnological applications for soil-borne disease control.

Numerical Simulation of Rocket Exhaust Interaction with Lunar Soil

NASA Technical Reports Server (NTRS)

Liever, Peter; Tosh, Abhijit; Curtis, Jennifer

2012-01-01

This technology development originated from the need to assess the debris threat resulting from soil material erosion induced by landing spacecraft rocket plume impingement on extraterrestrial planetary surfaces. The impact of soil debris was observed to be highly detrimental during NASA s Apollo lunar missions and will pose a threat for any future landings on the Moon, Mars, and other exploration targets. The innovation developed under this program provides a simulation tool that combines modeling of the diverse disciplines of rocket plume impingement gas dynamics, granular soil material liberation, and soil debris particle kinetics into one unified simulation system. The Unified Flow Solver (UFS) developed by CFDRC enabled the efficient, seamless simulation of mixed continuum and rarefied rocket plume flow utilizing a novel direct numerical simulation technique of the Boltzmann gas dynamics equation. The characteristics of the soil granular material response and modeling of the erosion and liberation processes were enabled through novel first principle-based granular mechanics models developed by the University of Florida specifically for the highly irregularly shaped and cohesive lunar regolith material. These tools were integrated into a unique simulation system that accounts for all relevant physics aspects: (1) Modeling of spacecraft rocket plume impingement flow under lunar vacuum environment resulting in a mixed continuum and rarefied flow; (2) Modeling of lunar soil characteristics to capture soil-specific effects of particle size and shape composition, soil layer cohesion and granular flow physics; and (3) Accurate tracking of soil-borne debris particles beginning with aerodynamically driven motion inside the plume to purely ballistic motion in lunar far field conditions. In the earlier project phase of this innovation, the capabilities of the UFS for mixed continuum and rarefied flow situations were validated and demonstrated for lunar lander rocket plume flow impingement under lunar vacuum conditions. Applications and improvements to the granular flow simulation tools contributed by the University of Florida were tested against Earth environment experimental results. Requirements for developing, validating, and demonstrating this solution environment were clearly identified, and an effective second phase execution plan was devised. In this phase, the physics models were refined and fully integrated into a production-oriented simulation tool set. Three-dimensional simulations of Apollo Lunar Excursion Module (LEM) and Altair landers (including full-scale lander geometry) established the practical applicability of the UFS simulation approach and its advanced performance level for large-scale realistic problems.

Phytoremediation and phytomining: Using plants to remediate contaminated or mineralized environments

USDA-ARS?s Scientific Manuscript database

One type of harsh environment for plants is metal and metalloid contaminated or mineralized soils which exist in most countries due to geological formations or to the history of mining and smelting. Depending on soil pH and fertility, metal-rich soils may be barren and eroding into wider areas. Some...

Soil Minerals Affect Extracellular Enzyme Activities in Cold and Warm Environments

NASA Astrophysics Data System (ADS)

Yang, Z.; Morin, M. M.; Graham, D. E.; Wullschleger, S. D.; Gu, B.

2017-12-01

Extracellular enzymes are mainly responsible for degrading and cycling soil organic matter (SOM) in both cold and warm terrestrial ecosystems. Minerals can play important roles in affecting soil enzyme activities, however, the interactions between enzyme and soil minerals remain poorly understood. In this study, we developed a model soil-enzyme system to examine the mineral effects on a hydrolytic enzyme (i.e., β-glucosidase) under both cold (4°C) and relatively warm (20 and 30°C) conditions. Minerals including iron oxides and clays (e.g., kaolinite and montmorillonite) were used to mimic different types of soils, and enzyme adsorption experiments were conducted to determine the enzyme interactions with different mineral surfaces. Time-series experiments were also carried out to measure enzymatic degradation of the organic substrates, such as cellobiose and indican. We observed that fractions of adsorbed enzyme and the hydrolytic activity were higher on iron oxides (e.g., hematite) compared to kaolinite and montmorillonite at given experimental conditions. The degradation of cellobiose was significantly faster than that of indican in the presence of minerals. We also found that the adsorption of enzyme was not dependent on the mineral surface areas, but was controlled by the mineral surface charge. In addition, temperature increase from 4 to 30°C enhanced mineral-assisted glucosidase hydrolysis by 2 to 4 fold, suggesting greater degradation under warmer environments. The present work demonstrates that the enzyme activity is influenced not only by the soil temperature but also by the surface chemistry of soil minerals. Our results highlight the need to consider the physical and chemical properties of minerals in biogeochemical models, which could provide a better prediction for enzyme-facilitated SOM transformations in terrestrial ecosystems.

Testing the capability of ORCHIDEE land surface model to simulate Arctic ecosystems: Sensitivity analysis and site-level model calibration

NASA Astrophysics Data System (ADS)

Dantec-Nédélec, S.; Ottlé, C.; Wang, T.; Guglielmo, F.; Maignan, F.; Delbart, N.; Valdayskikh, V.; Radchenko, T.; Nekrasova, O.; Zakharov, V.; Jouzel, J.

2017-06-01

The ORCHIDEE land surface model has recently been updated to improve the representation of high-latitude environments. The model now includes improved soil thermodynamics and the representation of permafrost physical processes (soil thawing and freezing), as well as a new snow model to improve the representation of the seasonal evolution of the snow pack and the resulting insulation effects. The model was evaluated against data from the experimental sites of the WSibIso-Megagrant project (www.wsibiso.ru). ORCHIDEE was applied in stand-alone mode, on two experimental sites located in the Yamal Peninsula in the northwestern part of Siberia. These sites are representative of circumpolar-Arctic tundra environments and differ by their respective fractions of shrub/tree cover and soil type. After performing a global sensitivity analysis to identify those parameters that have most influence on the simulation of energy and water transfers, the model was calibrated at local scale and evaluated against in situ measurements (vertical profiles of soil temperature and moisture, as well as active layer thickness) acquired during summer 2012. The results show how sensitivity analysis can identify the dominant processes and thereby reduce the parameter space for the calibration process. We also discuss the model performance at simulating the soil temperature and water content (i.e., energy and water transfers in the soil-vegetation-atmosphere continuum) and the contribution of the vertical discretization of the hydrothermal properties. This work clearly shows, at least at the two sites used for validation, that the new ORCHIDEE vertical discretization can represent the water and heat transfers through complex cryogenic Arctic soils—soils which present multiple horizons sometimes with peat inclusions. The improved model allows us to prescribe the vertical heterogeneity of the soil hydrothermal properties.

Characterizing Wheel-Soil Interaction Loads Using Meshfree Finite Element Methods: A Sensitivity Analysis for Design Trade Studies

NASA Technical Reports Server (NTRS)

Contreras, Michael T.; Trease, Brian P.; Bojanowski, Cezary; Kulakx, Ronald F.

2013-01-01

A wheel experiencing sinkage and slippage events poses a high risk to planetary rover missions as evidenced by the mobility challenges endured by the Mars Exploration Rover (MER) project. Current wheel design practice utilizes loads derived from a series of events in the life cycle of the rover which do not include (1) failure metrics related to wheel sinkage and slippage and (2) performance trade-offs based on grouser placement/orientation. Wheel designs are rigorously tested experimentally through a variety of drive scenarios and simulated soil environments; however, a robust simulation capability is still in development due to myriad of complex interaction phenomena that contribute to wheel sinkage and slippage conditions such as soil composition, large deformation soil behavior, wheel geometry, nonlinear contact forces, terrain irregularity, etc. For the purposes of modeling wheel sinkage and slippage at an engineering scale, meshfree nite element approaches enable simulations that capture su cient detail of wheel-soil interaction while remaining computationally feasible. This study implements the JPL wheel-soil benchmark problem in the commercial code environment utilizing the large deformation modeling capability of Smooth Particle Hydrodynamics (SPH) meshfree methods. The nominal, benchmark wheel-soil interaction model that produces numerically stable and physically realistic results is presented and simulations are shown for both wheel traverse and wheel sinkage cases. A sensitivity analysis developing the capability and framework for future ight applications is conducted to illustrate the importance of perturbations to critical material properties and parameters. Implementation of the proposed soil-wheel interaction simulation capability and associated sensitivity framework has the potential to reduce experimentation cost and improve the early stage wheel design proce

Carbonic anhydrase distribution across organisms and environments: genomic predictors for soil enzymatic fluxes of carbon cycle tracers δ18O and COS

NASA Astrophysics Data System (ADS)

Meredith, L. K.; Singer, E.

2016-12-01

Carbonyl sulfide (COS) and the oxygen isotope composition (δ18O) of CO2 are potential tools for differentiating the contributions of photosynthesis and respiration to the balance of global carbon cycling. These processes are coupled at the leaf level via the enzyme carbonic anhydrase (CA), which hydrolyzes CO2 in the first biochemical step of the photosynthetic pathway (CO2 + H2O ⇌ HCO3- + H+) and correspondingly structural analogue COS (COS + H2O → CO2 + H2S). CA also accelerates the exchange of oxygen isotopes between CO2 and H2O leading to a distinct isotopic imprint. The biogeochemical cycles of these tracers include significant, yet poorly characterized soil processes that challenge their utility for probing the carbon cycle. In soils, microbial CA also hydrolyze COS and accelerate O isotope exchange between CO2 and soil water. Genomic predictors of microbial CA activity may help account and predict for these soil fluxes. Using a bioinformatics approach, we assess the distribution of the six known CA classes (α, β, γ, δ, η, ζ) in organisms ranging from fungi and plants to archaea and bacteria, and ask whether CA diversity is linked to soil microbial diversity. We survey the diversity and relative abundance of CA in a wide variety of environments and estimate the sensitivity of CA to biome and land use. Finally, we compare the CA distribution in soils to measurements (oxygen isotope and COS fluxes) and models of CA activity to develop genomic predictors for CA activity. This work provides the first survey of CA in soils, a step towards understanding the significant role of CA in microbial ecology and microbe-mediated biogeochemical cycles.

Contamination of water and soil by the Erdenet copper-molybdenum mine in Mongolia

NASA Astrophysics Data System (ADS)

Battogtokh, B.; Lee, J.; Woo, N. C.; Nyamjav, A.

2013-12-01

As one of the largest copper-molybdenum (Cu-Mo) mines in the world, the Erdenet Mine in Mongolia has been active since 1978, and is expected to continue operations for at least another 30 years. In this study, the potential impacts of mining activities on the soil and water environments have been evaluated. Water samples showed high concentrations of sulfate, calcium, magnesium, Mo, and arsenic, and high pH values in the order of high to low as follows: tailing water > Khangal River > groundwater. Statistical analysis and the δ2H and δ18O values of water samples indicate that the tailing water directly affects the stream water and indirectly affects groundwater through recharge processes. Soil and stream sediments are highly contaminated with Cu and Mo, which are major elements of ore minerals. Based on the contamination factor (CF), the pollution load index (PLI), and the degree of contamination (Cd), soil appears to be less contaminated than stream sediments. The soil particle size is similar to that of tailing materials, but stream sediments have much coarser particles, implying that the materials have different origins. Contamination levels in stream sediments display a tendency to decrease with distance from the mine, but no such changes are found in soil. Consequently, soil contamination by metals is attributable to wind-blown dusts from the tailing materials, and stream sediment contamination is caused by discharges from uncontained subgrade ore stock materials. Considering the evident impact on the soil and water environment, and the human health risk from the Erdenet Mine, measures to mitigate its environmental impact should be taken immediately including source control, the establishment of a systematic and continuous monitoring system, and a comprehensive risk assessment. Sampling locations around the Erdenet Mine

Towards Soil and Sediment Inventories of Black Carbon

NASA Astrophysics Data System (ADS)

Masiello, C. A.

2008-12-01

A body of literature on black carbon (BC) concentrations in soils and sediments is rapidly accumulating, but as of yet, there are no global or regional inventories of BC in either reservoir. Soil and sediment BC inventories are badly needed for a range of fields. For example, in oceanography a global sediment BC inventory is crucial in understanding the role of biomass burning in the development of stable marine carbon reservoirs, including dissolved organic carbon and sedimentary organic carbon. Again in the marine environment, BC likely strongly impacts the fate and transport of anthropogenic pollutants: regional inventories of BC in sediments will help develop better environmental remediation strategies. In terrestrial systems well-constrained natural BC soil inventories would help refine ecological, agricultural, and soil biogeochemical studies. BC is highly sorptive of nutrients including nitrogen and phosphorous. The presence of BC in ecosystems almost certainly alters N and P cycling; however, without soil BC inventories, we cannot know where BC has a significant impact. BC's nutrient sorptivity and water-holding capacity make it an important component of agricultural soils, and some researchers have proposed artificially increasing soil BC inventories to improve soil fertility. Natural soil BC concentrations in some regions are quite high, but without a baseline inventory, it is challenging to predict when agricultural amendment will significantly exceed natural conditions. And finally, because BC is one of the most stable fractions of organic carbon in soils, understanding its concentration and regional distribution will help us track the dynamics of soil organic matter response to changing environmental conditions. Developing effective regional and global BC inventories is challenging both because of data sparsity and methodological intercomparison issues. In this presentation I will describe a roadmap to generating these valuable inventories.

Sorption and degradation of selected pharmaceuticals in representative soils of the Czech Republic

NASA Astrophysics Data System (ADS)

Kodesova, Radka; Kocarek, Martin; Klement, Ales; Golovko, Oksana; Grabic, Roman; Fer, Miroslav; Nikodem, Antonin; Jaksik, Ondrej

2015-04-01

Knowledge of contaminant behavior (e.g. its sorption onto soil particle, degradation etc.) is essential when assessing contaminant migration in soil and groundwater environment. This study was focused on evaluating sorption isotherms and half-lives for 7 pharmaceuticals (clarithromycin, trimethoprim, metoprolol, atenolol, clindamycin, carbamazepine, sulfamethoxazole) on 13 soils of different soil properties. Sorption of ionizable compounds was highly affected by soil pH. The sorption coefficient of sulfamethoxazole was negatively correlated to soil pH and thus positively related to hydrolytic acidity and exchangeable acidity. Sorption coefficients for clindamycin and clarithromycin were positively related to soil pH and thus negatively related to hydrolytic acidity and exchangeable acidity and positively related to base cation saturation. Sorption coefficients for the remaining pharmaceuticals (trimethoprim, metoprolol, atenolol, and carbamazepine) were also positively correlated with the base cation saturation and cation exchange capacity. Degradation rates in some degree reflected sorption of studied pharmaceuticals on soil particles and increased with decreasing sorption. The highest mobility in studied soils was observed for sulfamethoxazole, but this pharmaceutical was relatively quickly degraded. The second highest mobility was found for carbamazepine, which mostly did not noticeably degrade during our experiments. Thus this pharmaceutical has the highest potential to migrate in water environment. The lowest mobility was observed for clarithromycin. However, this pharmaceutical due to its stability may be retained in an environment for a long time. Acknowledgement: The authors acknowledge the financial support of the Czech Science Foundation (Project No. 13-12477S, Transport of pharmaceuticals in soils). References: Kodesova, R., Grabic, R., Kocarek, M., Klement, A., Golovko, O., Fer, M., Nikodem, A., Jaksik, O., Pharmaceuticals' sorptions relative to properties of thirteen different soils. Science of the Total Environment 511 (2015) 435-443.

Biogeosystem technique as a method to overcome the Biological and Environmental Hazards of modern Agricultural, Irrigational and Technological Activities

NASA Astrophysics Data System (ADS)

Kalinitchenko, Valery; Batukaev, Abdulmalik; Zinchenko, Vladimir; Zarmaev, Ali; Magomadov, Ali; Chernenko, Vladimir; Startsev, Viktor; Bakoev, Serojdin; Dikaev, Zaurbek

2014-05-01

Modern challenge for humanity is to replace the paradigm of nature use and overcome environmental hazards of agronomy, irrigation, industry, and other human activities in biosphere. It is utterly reasonable to stop dividing biosphere on shares - the human habitat and the environment. In the 21st century it is an outdated anthropocentrism. Contradicting himself to biosphere Humankind has the problems. The new paradigm of biosphere control by methods of Biogeosystem technique is on agenda of Humankind. Key directions of Biogeosystem technique. Tillage. Single rotary milling 20…30-50…60 sm soil layer optimizes the evolution and environment of soil, creates a favorable conditions for the rhizosphere, increases the biological productivity of biosphere by 30-50% compared to the standard agricultural practices for the period up to 40 years. Recycle material. Recycling of mineral and organic substances in soil layer of 20…30-50…60 sm in rotary milling soil processing provides wastes clean return to biosphere. Direct intrasoil substances synthesis. Environmentally friendly robot wasteless nanotechnology provides direct substances synthesis, including fertilizers, inside the soil. It eliminates the prerequisites of the wastes formation under standard industrial technologies. Selective substance's extraction from soil. Electrochemical robotic nanotechnology provides selective substances extraction from soil. The technology provides recovery, collection and subsequent safe industrial use of extracted substances out of landscape. Saving fresh water. An important task is to save fresh water in biosphere. Irrigation spends water 4-5 times more of biological requirements of plants, leads to degradation of soil and landscape. The intrasoil pulse continuous-discrete paradigm of irrigation is proposed. It provides the soil and landscape conservation, increases the biological productivity, save the fresh water up to 10-20 times. The subsurface soil rotary processing and intrasoil pulsed continuous-discrete irrigation provide environmentally safe disposal of municipal, industrial, biological and agricultural wastes. Hazardous chemical and biological agents are under the soil surface. It provided a medical and veterinary safety of environment. Biogeosystem technic controls the equilibria in the soil and soil solution, prevents excessive mineralization of organic matter in the surface layers of soil. Simultaneously a soil chemical reduction excluded, biological substance do not degrade to gases. Products of organic matter decomposition are directed to the food chain, 100% waste recycling is obtained. Biogeosystems technique allows producing more biological products hence to recycle excessive amount of man-made CO2 and other substances. Biogeosystems technique increases the rate of photosynthesis of the biosphere, the degree of air ionization. This enhances the formation of rains over land, ensures stability of the ionosphere, magnetosphere and atmosphere of Earth. The nowadays technologies allow applying technical solutions based on Biogeosystem technique, there is unique opportunity to accelerate the noosphere new technological platform.

[Effects of different crop rotations on growth of continuous cropping sorghum and its rhizosphere soil micro-environment.

PubMed

Wang, Jin Song; Fan, Fang Fang; Guo, Jun; Wu, Ai Lian; Dong, Er Wei; Bai, Wen Bin; Jiao, Xiao Yan

2016-07-01

The effects of crop rotation on sorghum [Sorghum biocolor (L) Moench] growth, rhizosphere microbial community and the activity of soil enzymes for successive crops of sorghum were evaluated. Five years of continuous monoculture sorghum as the control (CK) was compared to alfalfa and scallion planted in the fourth year. The results showed that incorporation of alfalfa and scallion into the rotation significantly improved sorghum shoot growth. Specifically, sorghum grain yield increased by 16.5% in the alfalfa rotation plots compared to the CK. The rotations also increased sorghum root system growth, with alfalfa or scallion rotation increasing sorghum total root length by 0.3 and 0.4 times, total root surface area by 0.6 and 0.5 times, root volume by 1.2 and 0.6 times, and root biomass by 1.0 and 0.3 times, respectively. Alfalfa rotation also expanded sorghum root distribution below the 10 cm soil depth. A Biolog analysis on biome functions in the sorghum flowering period indicated significantly higher microbial activity in the rotation plots. The alfalfa and scallion rotation increased the Shannon index by 0.2 and 0.1 times compared to the CK, and improved the sucrose activity in the rhizosphere soil. It was concluded that including alfalfa in rotation with sorghum improved sorghum rhizosphere soil environment, enhanced soil microbial enzyme activity, alleviated the obstacle of continuous cropping and thus increased the sorghum yield.

High abundance and diversity of nitrite-dependent anaerobic methane-oxidizing bacteria in a paddy field profile.

PubMed

Zhou, Leiliu; Wang, Yu; Long, Xi-En; Guo, Jianhua; Zhu, Guibing

2014-11-01

The discovery of nitrite-dependent anaerobic methane oxidation (n-damo) mediated by 'Candidatus Methylomirabilis oxyfera' with nitrite and methane as substrates has connected biogeochemical carbon and nitrogen cycles in a new way. The paddy fields often carry substantial methane and nitrate, thus may be a favorable habitat for n-damo bacteria. In this paper, the vertical-temporal molecular fingerprints of M. oxyfera-like bacteria, including abundance and community composition, were investigated in a paddy soil core in Jiangyin, near the Yangtze River. Through qPCR investigation, high abundance of M. oxyfera-like bacteria up to 1.0 × 10(8) copies (g d.w.s.)(-1) in summer and 8.5 × 10(7) copies (g d.w.s.)(-1) in winter was observed in the ecotone of soil and groundwater in the paddy soil core, which was the highest in natural environments to our knowledge. In the ecotone, the ratio of M. oxyfera-like bacteria to total bacteria reached peak values of 2.80% in summer and 4.41% in winter. Phylogenetic analysis showed n-damo bacteria in the paddy soil were closely related to M. oxyfera and had high diversity in the soil/groundwater ecotone. All of the results indicated the soil/groundwater ecotone of the Jiangyin paddy field was a favorable environment for the growth of n-damo bacteria. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Fluoroquinolones (FQs) in the environment: A review on their abundance, sorption and toxicity in soil.

PubMed

Riaz, Luqman; Mahmood, Tariq; Khalid, Azeem; Rashid, Audil; Ahmed Siddique, Muhammad Bashir; Kamal, Atif; Coyne, Mark S

2018-01-01

The use of fluoroquinolones (FQs) antibiotics as therapeutic agents and growth promoters is increasing worldwide; however their extensive uses are also resulting in antibiotic resistance among world communities. FQs have also become one of the major contaminants in the waste water bodies, which are not even completely removed during the treatment processes. Furthermore, their abundance in agricultural resources, such as the irrigation water, the bio-solids and the livestock manure can also affect the soil micro-environment. These antibiotics in soil tend to interact in several different ways to affect soil flora and fauna. The current review endeavors to highlight the some critical aspects of FQs prevalence in the environment. The review presents a detailed discussion on the pathways and abundance of FQs in soil. The discussion further spans the issue of sorption and FQs transformation into the soil better understand of their behavior and their toxicity to soil flora and fauna. Copyright © 2017 Elsevier Ltd. All rights reserved.

Research progress on expansive soil cracks under changing environment.

PubMed

Shi, Bei-xiao; Zheng, Cheng-feng; Wu, Jin-kun

2014-01-01

Engineering problems shunned previously rise to the surface gradually with the activities of reforming the natural world in depth, the problem of expansive soil crack under the changing environment becoming a control factor of expansive soil slope stability. The problem of expansive soil crack has gradually become a research hotspot, elaborates the occurrence and development of cracks from the basic properties of expansive soil, and points out the role of controlling the crack of expansive soil strength. We summarize the existing research methods and results of expansive soil crack characteristics. Improving crack measurement and calculation method and researching the crack depth measurement, statistical analysis method, crack depth and surface feature relationship will be the future direction.

Outdoor Activities.

ERIC Educational Resources Information Center

Minneapolis Independent School District 275, Minn.

Twenty-four activities suitable for outdoor use by elementary school children are outlined. Activities designed to make children aware of their environment include soil painting, burr collecting, insect and pond water collecting, studies of insect galls and field mice, succession studies, and a model of natural selection using dyed toothpicks. A…

Total phenolic levels in diverse garlics (Allium sativum L.)

USDA-ARS?s Scientific Manuscript database

Garlic (Allium sativum L.) is a specialty crop that is highly responsive to growth environment with respect to bulb size and coloration. Ten genetically diverse garlic cultivars were grown at twelve locations for two consecutive years. Soil characteristics and bulb phenotypic characters including ...

Delineation, Validation and Application of EPA’s Level III and IV Ecoregions in New England

EPA Science Inventory

EPA’s ecoregions are defined as areas of similarity based on patterns and composition of aquatic and terrestrial ecosystem components of the abiotic (non-living), biotic (living), and cultural (human) environment, including geology, physiography, vegetation, climate, soils, hydro...

Profiling the decomposition odour at the grave surface before and after probing.

PubMed

Forbes, S L; Troobnikoff, A N; Ueland, M; Nizio, K D; Perrault, K A

2016-02-01

Human remains detection (HRD) dogs are recognised as a valuable and non-invasive search method for remains concealed in many different environments, including clandestine graves. However, the search for buried remains can be a challenging task as minimal odour may be available at the grave surface for detection by the dogs. Handlers often use a soil probe during these searches in an attempt to increase the amount of odour available for detection, but soil probing is considered an invasive search technique. The aim of this study was to determine whether the soil probe assists with increasing the abundance of volatile organic compounds (VOCs) available at the grave surface. A proof-of-concept method was developed using porcine remains to collect VOCs within the grave without disturbing the burial environment, and to compare their abundance at the grave surface before and after probing. Detection and identification of the VOC profiles required the use of comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC×GC-TOFMS) due to its superior sensitivity and selectivity for decomposition odour profiling. The abundance of decomposition VOCs was consistently higher within the grave environment compared to the grave surface, except when the grave surface had been disturbed, confirming the reduced availability of odour at the grave surface. Although probing appeared to increase the abundance of VOCs at the grave surface on many of the sampling days, there were no clear trends identified across the study and no direct relationships with the environmental variables measured. Typically, the decomposition VOCs that were most prevalent in the grave soil were the same VOCs detected at the grave surface, whereas the trace VOCs detected in these environments varied throughout the post-burial period. This study highlighted that probing the soil can assist with releasing decomposition VOCs but is likely correlated to environmental and burial variables which require further study. The use of a soil probe to assist HRD dogs should not be disregarded but should only follow the use of non-invasive methods if deemed appropriate. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Tectonic uplift and denudation rate influence soil chemical weathering intensity in a semi-arid environment, southeast Spain: physico-chemical and mineralogical evidence

NASA Astrophysics Data System (ADS)

Ameijeiras-Mariño, Yolanda; Opfergelt, Sophie; Schoonejans, Jérôme; Vanacker, Veerle; Sonnet, Philippe; Delmelle, Pierre

2015-04-01

Tectonic uplift is known to influence denudation rates. Denudation, including chemical weathering and physical erosion, affects soil production rates and weathering intensities. At topographic steady state, weathering can be transport- or weathering-limited. In the transport-limited regime, low denudation rates should lead to comparatively high weathering intensities, while in the weathering-limited case high denudation rates are associated with lower weathering intensities. Here, we test if this relationship applies to semi-arid environments where chemical weathering is generally slow. Three catchments (EST, FIL and CAB) were studied in the Internal Zone of the Betic Cordillera in southeast Spain, spanning a range of increasing uplift rates (10-170 mm/kyr) and increasing denudation rates (20-250 mm/kyr) from EST to CAB. In each catchment, two ridgetop soil profiles were sampled down to the bedrock. The three catchments have similar vegetation and climatic conditions, with precipitation of 250- 315 mm/yr and mean annual temperature of 15-17 °C. The mineralogy of the bedrock, as determined by XRD, is similar across the three catchments and is characterized by the presence of quartz, muscovite, clinochlore, biotite and plagioclase. This primary mineral assemblage is also found in the catchment soils, indicating that the soils studied derive from the same parent material. The soil clay-size fraction is dominated by kaolinite, vermiculite and illite. However, the proportions of the soil primary and secondary minerals vary between the catchment sites. The abundance of biotite decreases from CAB (14%) to EST (4%), whereas the quartz and clay contents show an opposite tendency (from 30 to 69% and 9.9 to 14.3%, respectively). Further, the abundance of vermiculite increases from CAB to EST. The results are interpreted in terms of increasing weathering intensity from CAB to EST by weathering of biotite into vermiculite and enrichment of soils on more weathering resistant quartz. Soil weathering intensity in each catchment was assessed previously [1] using three independent weathering indices: the Total Reserve in Bases (TRB = [Ca2+] + [Na+] + [K+] + [Mg2+]), soil Fed/Fet ratio (Fe-oxides/total Fe), and Cation Exchange Capacity (CEC). In agreement with the soil mineralogy, the physico-chemical analyses revealed increasing weathering intensity from CAB to EST. We postulate that the higher chemical weathering intensity in EST reflects lower denudation and uplift rates compared to CAB and therefore, soil chemical weathering intensity in this semi-arid environment may be controlled by denudation and uplift rates [1] Ameijeiras-Mariño et al, EGU 2014-9714-1

Current research trends on plastic pollution and ecological impacts on the soil ecosystem: A review.

PubMed

Chae, Yooeun; An, Youn-Joo

2018-05-09

Plastic pollution in the environment is currently receiving worldwide attention. Improper dumping of disused or abandoned plastic wastes leads to contamination of the environment. In particular, the disposal of municipal wastewater effluent, sewage sludge landfill, and plastic mulch from agricultural activities is a serious issue and of major concern regarding soil pollution. Compared to plastic pollution in the marine and freshwater ecosystems, that in the soil ecosystem has been relatively neglected. In this study, we discussed plastic pollution in the soil environment and investigated research on the effects of plastic wastes, especially microplastics, on the soil ecosystem. We found that earthworms have been predominantly used as the test species in investigating the effects of soil plastic pollution on organisms. Therefore, further research investigating the effects of plastic on other species models (invertebrates, plants, microorganisms, and insects) are required to understand the effects of plastic pollution on the overall soil ecosystem. In addition, we suggest other perspectives for future studies on plastic pollution and soil ecotoxicity of plastics wastes, providing a direction for such research. Copyright © 2018 Elsevier Ltd. All rights reserved.

Environmental Controls on Multi-Scale Soil Nutrient Variability in the Tropics: the Importance of Land-Cover Change

NASA Astrophysics Data System (ADS)

Holmes, K. W.; Kyriakidis, P. C.; Chadwick, O. A.; Matricardi, E.; Soares, J. V.; Roberts, D. A.

2003-12-01

The natural controls on soil variability and the spatial scales at which correlation exists among soil and environmental variables are critical information for evaluating the effects of deforestation. We detect different spatial scales of variability in soil nutrient levels over a large region (hundreds of thousands of km2) in the Amazon, analyze correlations among soil properties at these different scales, and evaluate scale-specific relationships among soil properties and the factors potentially driving soil development. Statistical relationships among physical drivers of soil formation, namely geology, precipitation, terrain attributes, classified soil types, and land cover derived from remote sensing, were included to determine which factors are related to soil biogeochemistry at each spatial scale. Surface and subsurface soil profile data from a 3000 sample database collected in Rond“nia, Brazil, were used to investigate patterns in pH, phosphorus, nitrogen, organic carbon, effective cation exchange capacity, calcium, magnesium, potassium, aluminum, sand, and clay in this environment grading from closed canopy tropical forest to savanna. We focus on pH in this presentation for simplicity, because pH is the single most important soil characteristic for determining the chemical environment of higher plants and soil microbial activity. We determined four spatial scales which characterize integrated patterns of soil chemistry: less than 3 km; 3 to 10 km; 10 to 68 km; and from 68 to 550 km (extent of study area). Although the finest observable scale was fixed by the field sampling density, the coarser scales were determined from relationships in the data through coregionalization modeling, rather than being imposed by the researcher. Processes which affect soils over short distances, such as land cover and terrain attributes, were good predictors of fine scale spatial components of nutrients; processes which affect soils over very large distances, such as precipitation and geology, were better predictors at coarse spatial scales. However, this result may be affected by the resolution of the available predictor maps. Land-cover change exerted a strong influence on soil chemistry at fine spatial scales, and had progressively less of an effect at coarser scales. It is important to note that land cover, and interactions among land cover and the other predictors, continued to be a significant predictor of soil chemistry at every spatial scale up to hundreds of thousands of kilometers.

The impact of 90 years of drainage works on some chemical properties of raised peat bog organic soils - case study from valley of the Upper San river in Polish Bieszczady Mts. (Eastern Carpathians).

NASA Astrophysics Data System (ADS)

Stolarczyk, Mateusz

2016-04-01

Wetland ecosystems, including raised peat bogs are characterized by a specific water conditions and unique vegetation, which makes peatland highly important habitats due to protection of biodiversity. Transformation of peat bog areas is particularly related to changes in the environment e.g. according to reclamation works. Drainage of peatlands is directly associated to the decrease of groundwater levels and lead to a number of changes in the chemical and physical properties of peat material, included contents of exchangeable cations in the surface layers of peat soils in the decession phase of peat development and release above compounds from the soil to ground or surface waters. The aim of the research was to determine the impact of extended drainage works on chemical composition of sorption complex of raised peat bog organic soils and identification the potential environmental effects of alkaline cations leaching to the surface waters. Research was carried out on the peat bogs located in the Upper San valley in Polish Bieszczady Mts. (Eastern Carpathians). Soil samples used in this study were collected from 3 soil profiles in 10 or 20 cm intervals to the approximately 130 cm depth. Laboratory analyses included determination of basic properties of organic material such as the degree of peat decomposition, ash content, soil pH and carbon, hydrogen, nitrogen concentrations. Additionally the amount of alkaline cations, exchangeable and extractable acidity was determined. Furthermore, the degree of saturation of the sorption complex with alkaline cations (V) and cation exchange capacity (CEC) are calculated. In order to evaluate the impact of the examined peat bog to the environment, also water samples were collected and ions composition was measured. The obtained results show that studied organic soils are oligotrophic and strongly acidic. In the case of organic material related to decession phase of peat development, as a result of the lengthy drainage works, increased pH values, changes in the morphology of the peat, high nitrogen contents and lower values of C/N ratios are noticed. The increased contents of calcium, occurred in soil layers comprised of moorsh forming process are probably the effect of peat mineralization process or changes in the chemistry and fluctuations of groundwater levels. As a result of above factors, increased calcium and magnesium concentrations in surface waters in the immediate vicinity of investigated bogs are observed.

Project Plan for Recreation Resources Development. North Hartland Lake, Hartland and Hartford, Vermont.

DTIC Science & Technology

1981-01-01

of reservoir management are included within the scope of thle project plan. The plan represents a culmination of knowledge gathered from past...a detailed inventory and analysis of the projects natural resources in order to minimize environment and aesthetic impact, promote logical development...and minimize development costs. Factors inventoried included soil types, vegetation, topography, wildlife, surface geology, historical

Tablet and Face-to-Face Hybrid Professional Development: Providing Earth Systems Science Educators Authentic Research Opportunities through The GLOBE Program at Purdue University

NASA Astrophysics Data System (ADS)

Wegner, K.; Branch, B. D.; Smith, S. C.

2013-12-01

The Global Learning and Observations to Benefit the Environment (GLOBE) program is a worldwide hands-on, primary and secondary school-based science and education program (www.globe.gov). GLOBE's vision promotes and supports students, teachers and scientists to collaborate on inquiry-based authentic science investigations of the environment and the Earth system working in close partnership with NASA, NOAA and NSF Earth System Science Projects (ESSP's) in study and research about the dynamics of Earth's environment. GLOBE Partners conduct face-to-face Professional Development in more than 110 countries, providing authentic scientific research experience in five investigation areas: atmosphere, earth as a system, hydrology, land cover, and soil. This presentation will provide a sample for a new framework of Professional Development that was implemented in July 2013 at Purdue University lead by Mr. Steven Smith who has tested GLOBE training materials for future training. The presentation will demonstrate how institutions can provide educators authentic scientific research opportunities through various components, including: - Carrying out authentic research investigations - Learning how to enter their authentic research data into the GLOBE database and visualize it on the GLOBE website - Learn how to access to NASA's Earth System Science resources via GLOBE's new online 'e-Training Program' - Exploring the connections of their soil protocol measurements and the history of the soil in their area through iPad soils app - LIDAR data exposure, Hydrology data exposure

Novel Proximal Sensing for Monitoring Soil Organic C Stocks and Condition.

PubMed

Viscarra Rossel, Raphael A; Lobsey, Craig R; Sharman, Chris; Flick, Paul; McLachlan, Gordon

2017-05-16

Soil information is needed for environmental monitoring to address current concerns over food, water and energy securities, land degradation, and climate change. We developed the Soil Condition ANalysis System (SCANS) to help address these needs. It integrates an automated soil core sensing system (CSS) with statistical analytics and modeling to characterize soil at fine depth resolutions and across landscapes. The CSS's sensors include a γ-ray attenuation densitometer to measure bulk density, digital cameras to image the measured soil, and a visible-near-infrared (vis-NIR) spectrometer to measure iron oxides and clay mineralogy. The spectra are also modeled to estimate total soil organic carbon (C), particulate, humus, and resistant organic C (POC, HOC, and ROC, respectively), clay content, cation exchange capacity (CEC), pH, volumetric water content, available water capacity (AWC), and their uncertainties. Measurements of bulk density and organic C are combined to estimate C stocks. Kalman smoothing is used to derive complete soil property profiles with propagated uncertainties. The SCANS provides rapid, precise, quantitative, and spatially explicit information about the properties of soil profiles with a level of detail that is difficult to obtain with other approaches. The information gained effectively deepens our understanding of soil and calls attention to the central role soil plays in our environment.

Handbook of corrosion data, 2nd edition

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

Craig, B.; Anderson, D.

1995-12-31

As in the prior edition, in one convenient volume this book makes it easy to find what effect environment has on the corrosion of metals and alloys. Coverage on all the environments in the first edition has been updated and expanded and some 80 or more environments have been added, including food products (chocolate, milk, cider, beer, etc.), fruit juices (grape, pineapple, lemon, etc.), soil, blood, gasoline, fertilizers, etc. Presentation of the tabular information for all environments has been standardized throughout the book. The environments are listed alphabetically. Each listing includes a general description of the conditions, a comment onmore » the corrosion characteristics of various alloys in such a situation, a bibliography of recent articles specific to the environment, tables consolidating and comparing corrosion rates at various temperatures and concentrations for various alloys, and graphical information. also included are summaries on the general corrosion characteristics of major metals and alloys. This separate section of the book considers each material group, such as aluminum, stainless steel, zinc and so forth. Additional tables are presented here to give the corrosion characteristics of various alloys in hundreds of environments.« less

Applying soil science for restoration of post mining degraded landscapes in semi-arid Australia: challenges and opportunities

NASA Astrophysics Data System (ADS)

Muñoz-Rojas, Miriam; Martini, Dylan; Erickson, Todd; Merritt, David; Dixon, Kingsley

2015-04-01

Introduction Current challenges in ecological restoration of post mining environments include the deficit of original topsoil which is frequently lost or damaged, and the lack of soil forming materials. A comprehensive knowledge of soil properties and processes and an adequate management of soil resources are critical to improve the restoration success of these degraded areas. In particular, understanding soil physical, chemical and biological parameters is decisive in environments where water is a limiting factor for seedling establishment and plant survival. To improve the restoration success of biodiverse semi-arid areas disturbed by mining activities (Pilbara region, Western Australia), we conducted experiments to (i) analyse changes in soil physico-chemical properties and soil microbial activity of topsoil stockpiles to optimise its handling and minimise deterioration of nutrients and soil biota, (ii) test climate effects on seedling emergence of native plant species and (iii) assess the potential of mine waste materials as a suitable growth medium for seedling emergence of native plant species under various water regimes. Methods The experimental studies were conducted in controlled environment facilities where air temperature, relative humidity and soil moisture were monitored routinely. Watering regimes were selected to represent rainfall patterns of the area. As a growth media we used material obtained from topsoil stockpiles and waste materials from an active mine site, which were mixed at different ratios. Samples were collected from different parts of the topsoil stockpiles and analysed to determine physical, chemical and biological properties. Results No large discrepancies in physical and chemical values were detected at different positions of the stockpiles. However, microbial activity was highly variable, particularly inside the stockpiles. Seedling emergence on topsoil growth media was highly dependent on climate factors with emergence rates varying significantly (P< 0.001) across species. Highest emergence rates were obtained for Acacia adoxa and Grevillea pyramidalis in the 30°C scenario and adequate soil moisture levels (mean % ± SE 71±5.3 and 80±3.8 respectively). With available water, emergence was above 30% for all species and growth media types (topsoil, waste and mixes of topsoil and waste at 50:50 and 25:75 ratios). However, under drought conditions, emergence severely decreased for all species. In particular, Gossypium robinsonii and Grevillea pyramidalis did not show any response with less than 50% of topsoil in the composition of growth media. Our results suggest that changes in precipitation regimes can have a critical effect on seedling emergence of native plant species from the Pilbara. Understanding soil physico-chemical properties of soil materials and changes in soil moisture related to rainfall patterns and growth media blends are crucial to predict the success of seedling emergence and ultimately achieve biodiverse restoration in semiarid areas. This research is part of a broader multi-study approach, the Restoration Seedbank Initiative project, a partnership between The University of Western Australia, BHP Billiton Iron Ore, and Kings Park and Botanic Garden. Keywords Pilbara region, biodiverse ecosystems, soil microbial activity, topsoil stockpile, dry environments, land rehabilitation.

HYSOGs250m, global gridded hydrologic soil groups for curve-number-based runoff modeling.

PubMed

Ross, C Wade; Prihodko, Lara; Anchang, Julius; Kumar, Sanath; Ji, Wenjie; Hanan, Niall P

2018-05-15

Hydrologic soil groups (HSGs) are a fundamental component of the USDA curve-number (CN) method for estimation of rainfall runoff; yet these data are not readily available in a format or spatial-resolution suitable for regional- and global-scale modeling applications. We developed a globally consistent, gridded dataset defining HSGs from soil texture, bedrock depth, and groundwater. The resulting data product-HYSOGs250m-represents runoff potential at 250 m spatial resolution. Our analysis indicates that the global distribution of soil is dominated by moderately high runoff potential, followed by moderately low, high, and low runoff potential. Low runoff potential, sandy soils are found primarily in parts of the Sahara and Arabian Deserts. High runoff potential soils occur predominantly within tropical and sub-tropical regions. No clear pattern could be discerned for moderately low runoff potential soils, as they occur in arid and humid environments and at both high and low elevations. Potential applications of this data include CN-based runoff modeling, flood risk assessment, and as a covariate for biogeographical analysis of vegetation distributions.

NASA Giovanni: A Tool for Visualizing, Analyzing, and Inter-comparing Soil Moisture Data

NASA Technical Reports Server (NTRS)

Teng, William; Rui, Hualan; Vollmer, Bruce; deJeu, Richard; Fang, Fan; Lei, Guang-Dih; Parinussa, Robert

2014-01-01

There are many existing satellite soil moisture algorithms and their derived data products, but there is no simple way for a user to inter-compare the products or analyze them together with other related data. An environment that facilitates such inter-comparison and analysis would be useful for validation of satellite soil moisture retrievals against in situ data and for determining the relationships between different soil moisture products. As part of the NASA Giovanni (Geospatial Interactive Online Visualization ANd aNalysis Infrastructure) family of portals, which has provided users worldwide with a simple but powerful way to explore NASA data, a beta prototype Giovanni Inter-comparison of Soil Moisture Products portal has been developed. A number of soil moisture data products are currently included in the prototype portal. More will be added, based on user requirements and feedback and as resources become available. Two application examples for the portal are provided. The NASA Giovanni Soil Moisture portal is versatile and extensible, with many possible uses, for research and applications, as well as for the education community.

Earthworms as ecosystem engineers and the most important detritivors in forest soils.

PubMed

Kooch, Yahya; Jalilvand, Hamid

2008-03-15

Earthworms are considered as soil engineers because of their effects on soil properties and their influence on the availability of resources for other organisms, including microorganisms and plants. However, the links between their impacts on the soil environment and the resulting modification of natural selection pressures on engineer as well as on other organisms have received little attention. Earthworms are known to have a positive influence on the soil fabric and on the decomposition and mineralization of litter by breaking down organic matter and producing large amounts of fasces, thereby mixing litter with the mineral soil. Therefore, they play an important part in changes from one humus from to another according to forest succession patterns. Consequently, they are also expected to be good bio-indicators for forest site quality and are thus useful when planning forest production improvement. Earthworm's populations are as indicator that in exploited regions is destruction indicator and reclamation plans is nature return indicator. In this study we summarized the current knowledge in relation to earthworm's ecology in forest soils as ecosystem engineers.

Pyrethroid pesticide residues in the global environment: An overview.

PubMed

Tang, Wangxin; Wang, Di; Wang, Jiaqi; Wu, Zhengwen; Li, Lingyu; Huang, Mingli; Xu, Shaohui; Yan, Dongyun

2018-01-01

Pyrethroids are synthetic organic insecticides with low mammalian toxicity that are widely used in both rural and urban areas worldwide. After entering the natural environment, pyrethroids circulate among the three phases of solid, liquid, and gas and enter organisms through food chains, resulting in substantial health risks. This review summarized the available studies on pyrethroid residues since 1986 in different media at the global scale and indicated that pyrethroids have been widely detected in a range of environments (including soils, water, sediments, and indoors) and in organisms. The concentrations and detection rates of agricultural pyrethroids, which always contain α-cyanogroup (α-CN), such as cypermethrin and fenvalerate, decline in the order of crops > sediments > soils > water. Urban pyrethroids (not contain α-CN), such as permethrin, have been detected at high levels in the indoor environment, and 3-phenoxybenzoic acid, a common pyrethroid metabolite in human urine, is frequently detected in the human body. Pyrethroid pesticides accumulate in sediments, which are a source of pyrethroid residues in aquatic products. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Water Cycle, a Potential Source of the Bacterial Pathogen Bacillus cereus.

PubMed

Brillard, Julien; Dupont, Christian M S; Berge, Odile; Dargaignaratz, Claire; Oriol-Gagnier, Stéphanie; Doussan, Claude; Broussolle, Véronique; Gillon, Marina; Clavel, Thierry; Bérard, Annette

2015-01-01

The behaviour of the sporulating soil-dwelling Bacillus cereus sensu lato (B. cereus sl) which includes foodborne pathogenic strains has been extensively studied in relation to its various animal hosts. The aim of this environmental study was to investigate the water compartments (rain and soil water, as well as groundwater) closely linked to the primary B. cereus sl reservoir, for which available data are limited. B. cereus sl was present, primarily as spores, in all of the tested compartments of an agricultural site, including water from rain to groundwater through soil. During rain events, leachates collected after transfer through the soil eventually reached the groundwater and were loaded with B. cereus sl. In groundwater samples, newly introduced spores of a B. cereus model strain were able to germinate, and vegetative cells arising from this event were detected for up to 50 days. This first B. cereus sl investigation in the various types of interrelated environments suggests that the consideration of the aquatic compartment linked to soil and to climatic events should provide a better understanding of B. cereus sl ecology and thus be relevant for a more accurate risk assessment of food poisoning caused by B. cereus sl pathogenic strains.

The Water Cycle, a Potential Source of the Bacterial Pathogen Bacillus cereus

PubMed Central

Brillard, Julien; Dupont, Christian M. S.; Berge, Odile; Dargaignaratz, Claire; Oriol-Gagnier, Stéphanie; Doussan, Claude; Broussolle, Véronique; Gillon, Marina; Clavel, Thierry; Bérard, Annette

2015-01-01

The behaviour of the sporulating soil-dwelling Bacillus cereus sensu lato (B. cereus sl) which includes foodborne pathogenic strains has been extensively studied in relation to its various animal hosts. The aim of this environmental study was to investigate the water compartments (rain and soil water, as well as groundwater) closely linked to the primary B. cereus sl reservoir, for which available data are limited. B. cereus sl was present, primarily as spores, in all of the tested compartments of an agricultural site, including water from rain to groundwater through soil. During rain events, leachates collected after transfer through the soil eventually reached the groundwater and were loaded with B. cereus sl. In groundwater samples, newly introduced spores of a B. cereus model strain were able to germinate, and vegetative cells arising from this event were detected for up to 50 days. This first B. cereus sl investigation in the various types of interrelated environments suggests that the consideration of the aquatic compartment linked to soil and to climatic events should provide a better understanding of B. cereus sl ecology and thus be relevant for a more accurate risk assessment of food poisoning caused by B. cereus sl pathogenic strains. PMID:25918712

Identification of growth stage molecular markers in Trichoderma sp. 'atroviride type B' and their potential application in monitoring fungal growth and development in soil.

PubMed

Mendoza-Mendoza, Artemio; Steyaert, Johanna; Nieto-Jacobo, Maria Fernanda; Holyoake, Andrew; Braithwaite, Mark; Stewart, Alison

2015-11-01

Several members of the genus Trichoderma are biocontrol agents of soil-borne fungal plant pathogens. The effectiveness of biocontrol agents depends heavily on how they perform in the complex field environment. Therefore, the ability to monitor and track Trichoderma within the environment is essential to understanding biocontrol efficacy. The objectives of this work were to: (a) identify key genes involved in Trichoderma sp. 'atroviride type B' morphogenesis; (b) develop a robust RNA isolation method from soil; and (c) develop molecular marker assays for characterizing morphogenesis whilst in the soil environment. Four cDNA libraries corresponding to conidia, germination, vegetative growth and conidiogenesis were created, and the genes identified by sequencing. Stage specificity of the different genes was confirmed by either Northern blot or quantitative reverse-transcriptase PCR (qRT-PCR) analysis using RNA from the four stages. con10, a conidial-specific gene, was observed in conidia, as well as one gene also involved in subsequent stages of germination (L-lactate/malate dehydrogenase encoding gene). The germination stage revealed high expression rates of genes involved in amino acid and protein biosynthesis, while in the vegetative-growth stage, genes involved in differentiation, including the mitogen-activated protein kinase kinase similar to Kpp7 from Ustilago maydis and the orthologue to stuA from Aspergillus nidulans, were preferentially expressed. Genes involved in cell-wall synthesis were expressed during conidiogenesis. We standardized total RNA isolation from Trichoderma sp. 'atroviride type B' growing in soil and then examined the expression profiles of selected genes using qRT-PCR. The results suggested that the relative expression patterns were cyclic and not accumulative.

Mineralogical characteristics of Mn coatings from different weathering environments in China: clues on their formation

NASA Astrophysics Data System (ADS)

Xu, Xiaoming; Ding, Hongrui; Li, Yan; Lu, Anhuai; Li, Yan; Wang, Changqiu

2018-03-01

Identification of Mn oxides in natural Mn coatings is very difficult due to their poor crystallinity, fine grains, complex chemistry and tiny amounts. In this work, we investigated three types of Mn coatings including rock varnish, dendrite and soil Fe-Mn cutan from different weathering environments in China. Optical microscope, scanning electron microscope, energy dispersive X-ray spectroscopy and micro-Raman spectrometer were employed to achieve non-destructive, sensitive, in-situ and micro analysis on their mineral assemblages, micromorphological features and elemental distribution characteristics. The observed results suggest that rock varnish and soil cutan comprise birnessite, while dendrite is mainly composed of hollandite. Rock varnish with a layered structure has a clear boundary with its substrate, and microlaminations which arise from the fluctuations in Mn content (6.42-17.07 wt%) within the sample profile are obvious on closer inspection. Branch-like dendrite is rich in Mn (32.53-42.96 wt%) but poor in Si and Al, which shows a pilotaxitic texture with its substrate. Soil Fe-Mn cutan can be further divided into an outer black Mn-rich (8.26-13.58 wt%) belt and an inner yellowish-brown Fe-rich (2.06-4.85 wt%) belt, and a clear border can be identified between these two belts. Mn in the substrate of rock varnish and soil cutan is below detection limit while it can be detected in the substrate of dendrite (1.43-7.83 wt%). Our in-situ analysis provides more precise results than traditional powder test. These mineralogical characteristics indicate that dendrite is most likely endogenic, while rock varnish and soil cutan are external accretion formed under different weathering environments.

Integrated soil fertility management in sub-Saharan Africa: unravelling local adaptation

NASA Astrophysics Data System (ADS)

Vanlauwe, B.; Descheemaeker, K.; Giller, K. E.; Huising, J.; Merckx, R.; Nziguheba, G.; Wendt, J.; Zingore, S.

2014-12-01

Intensification of smallholder agriculture in sub-Saharan Africa is necessary to address rural poverty and natural resource degradation. Integrated Soil Fertility Management (ISFM) is a means to enhance crop productivity while maximizing the agronomic efficiency (AE) of applied inputs, and can thus contribute to sustainable intensification. ISFM consists of a set of best practices, preferably used in combination, including the use of appropriate germplasm, the appropriate use of fertilizer and of organic resources, and good agronomic practices. The large variability in soil fertility conditions within smallholder farms is also recognised within ISFM, including soils with constraints beyond those addressed by fertilizer and organic inputs. The variable biophysical environments that characterize smallholder farming systems have profound effects on crop productivity and AE and targeted application of limited agro-inputs and management practices is necessary to enhance AE. Further, management decisions depend on the farmer's resource endowments and production objectives. In this paper we discuss the "local adaptation" component of ISFM and how this can be conceptualized within an ISFM framework, backstopped by analysis of AE at plot and farm level. At plot level, a set of four constraints to maximum AE is discussed in relation to "local adaptation": soil acidity, secondary nutrient and micro-nutrient (SMN) deficiencies, physical constraints, and drought stress. In each of these cases, examples are presented whereby amendments and/or practices addressing these have a significantly positive impact on fertilizer AE, including mechanistic principles underlying these effects. While the impact of such amendments and/or practices is easily understood for some practices (e.g., the application of SMNs where these are limiting), for others, more complex interactions with fertilizer AE can be identified (e.g., water harvesting under varying rainfall conditions). At farm scale, adjusting fertilizer applications within-farm soil fertility gradients has the potential to increase AE compared with blanket recommendations, in particular where fertility gradients are strong. In the final section, "local adaption" is discussed in relation to scale issues and decision support tools are evaluated as a means to create a better understanding of complexity at farm level and to communicate best scenarios for allocating agro-inputs and management practices within heterogeneous farming environments.

Integrated soil fertility management in sub-Saharan Africa: unravelling local adaptation

NASA Astrophysics Data System (ADS)

Vanlauwe, B.; Descheemaeker, K.; Giller, K. E.; Huising, J.; Merckx, R.; Nziguheba, G.; Wendt, J.; Zingore, S.

2015-06-01

Intensification of smallholder agriculture in sub-Saharan Africa is necessary to address rural poverty and natural resource degradation. Integrated soil fertility management (ISFM) is a means to enhance crop productivity while maximizing the agronomic efficiency (AE) of applied inputs, and can thus contribute to sustainable intensification. ISFM consists of a set of best practices, preferably used in combination, including the use of appropriate germplasm, the appropriate use of fertilizer and of organic resources, and good agronomic practices. The large variability in soil fertility conditions within smallholder farms is also recognized within ISFM, including soils with constraints beyond those addressed by fertilizer and organic inputs. The variable biophysical environments that characterize smallholder farming systems have profound effects on crop productivity and AE, and targeted application of agro-inputs and management practices is necessary to enhance AE. Further, management decisions depend on the farmer's resource endowments and production objectives. In this paper we discuss the "local adaptation" component of ISFM and how this can be conceptualized within an ISFM framework, backstopped by analysis of AE at plot and farm level. At plot level, a set of four constraints to maximum AE is discussed in relation to "local adaptation": soil acidity, secondary nutrient and micronutrient (SMN) deficiencies, physical constraints, and drought stress. In each of these cases, examples are presented whereby amendments and/or practices addressing these have a significantly positive impact on fertilizer AE, including mechanistic principles underlying these effects. While the impact of such amendments and/or practices is easily understood for some practices (e.g. the application of SMNs where these are limiting), for others, more complex processes influence AE (e.g. water harvesting under varying rainfall conditions). At farm scale, adjusting fertilizer applications to within-farm soil fertility gradients has the potential to increase AE compared with blanket recommendations, in particular where fertility gradients are strong. In the final section, "local adaption" is discussed in relation to scale issues and decision support tools are evaluated as a means to create a better understanding of complexity at farm level and to communicate appropriate scenarios for allocating agro-inputs and management practices within heterogeneous farming environments.

Young calcareous soil chronosequences as a model for ecological restoration on alkaline mine tailings.

PubMed

Cross, Adam T; Lambers, Hans

2017-12-31

Tailings are artificial soil-forming substrates that have not been created by the natural processes of soil formation and weathering. The extreme pH environment and corresponding low availability of some macro- and micronutrients in alkaline tailings, coupled with hostile physical and geochemical conditions, present a challenging environment to native biota. Some significant nutritional constraints to ecosystem reconstruction on alkaline tailings include i) predominant or complete absence of combined nitrogen (N) and poor soil N retention; ii) the limited bioavailability of some micronutrients at high soil pH (e.g., Mn, Fe, Zn and Cu); and iii) potentially toxic levels of biologically available soil phosphorus (P) for P-sensitive plants. The short regulatory time frames (years) for mine closure on tailings landforms are at odds with the long time required for natural pedogenic processes to ameliorate these factors (thousands of years). However, there are similarities between the chemical composition and nutrient status of alkaline tailings and the poorly-developed, very young calcareous soils of biodiverse regions such as south-western Australia. We propose that basic knowledge of chronosequences that start with calcareous soils may provide an informative model for understanding the pedogenic processes required to accelerate soil formation on tailings. Development of a functional, stable root zone is crucial to successful ecological restoration on tailings, and three major processes should be facilitated as early as possible during processing or in the early stages of restoration to accelerate soil development on alkaline tailings: i) acidification of the upper tailings profile; ii) establishment of appropriate and resilient microbial communities; and iii) the early development of appropriate pioneer vegetation. Achieving successful ecological restoration outcomes on tailings landforms is likely one of the greatest challenges faced by restoration ecologists and the mining industry, and successful restoration on alkaline tailings likely depends upon careful management of substrate chemical conditions by targeted amendments. Copyright © 2017 Elsevier B.V. All rights reserved.

Assessing soil and groundwater contamination from biofuel spills.

PubMed

Chen, Colin S; Shu, Youn-Yuen; Wu, Suh-Huey; Tien, Chien-Jung

2015-03-01

Future modifications of fuels should include evaluation of the proposed constituents for their potential to damage environmental resources such as the subsurface environment. Batch and column experiments were designed to simulate biofuel spills in the subsurface environment and to evaluate the sorption and desorption behavior of target fuel constituents (i.e., monoaromatic and polyaromatic hydrocarbons) in soil. The extent and reversibility of the sorption of aromatic biofuel constituents onto soil were determined. When the ethanol content in ethanol-blended gasoline exceeded 25%, enhanced desorption of the aromatic constituents to water was observed. However, when biodiesel was added to diesel fuel, the sorption of target compounds was not affected. In addition, when the organic carbon content of the soil was higher, the desorption of target compounds into water was lower. The empirical relationships between the organic-carbon normalized sorption coefficient (Koc) and water solubility and between Koc and the octanol-water partition coefficient (Kow) were established. Column experiments were carried out for the comparison of column effluent concentration/mass from biofuel-contaminated soil. The dissolution of target components depended on chemical properties such as the hydrophobicity and total mass of biofuel. This study provides a basis for predicting the fate and transport of hydrophobic organic compounds in the event of a biofuel spill. The spill scenarios generated can assist in the assessment of biofuel-contaminated sites.

Soil fauna community in the black soil of northeast China under different conservation tillage systems

USDA-ARS?s Scientific Manuscript database

Soil fauna is an important component in soil ecosystem. Through the soil moisture changes, soil environment is changed under different tillage systems, and then the population of soil fauna also is changed. This study tested whether conservation tillage or conventional tillage (CT) of black soil fie...

Vadose zone transport of natural and synthetic estrogen hormones at Penn State's "Living Filter" wastewater irrigation site

USDA-ARS?s Scientific Manuscript database

The increase in endocrine disrupting compounds (EDCs) in the environment has generated new research focused on the behavior of these compounds in natural soil and water ecosystems. To understand how estrogens behave in the soil environment as a result of 25+ years of wastewater irrigation, soils fro...

Plant rhizosphere species-specific stoichiometry and regulation of extracellular enzyme and microbial community structure

NASA Astrophysics Data System (ADS)

Bell, C. W.; Calderon, F.; Pendall, E.; Wallenstein, M. D.

2012-12-01

Plant communities affect the activity and composition of soil microbial communities through alteration of the soil environment during root growth; substrate availability through root exudation; nutrient availability through plant uptake; and moisture regimes through transpiration. As a result, positive feedbacks in soil properties can result from alterations in microbial community composition and function in the rhizosphere zone. At the ecosystem-scale, many properties of soil microbial communities can vary between forest stands dominated by different species, including community composition and stoichiometry. However, the influence of smaller individual plants on grassland soils and microbial communities is less well documented. There is evidence to suggest that some plants can modify their soil environment in a manner that favors their persistence. For example, when Bromus tectorum plants invade, soil microbial communities tend to have higher N mineralization rates (in the rhizosphere zone) relative to native plants. If tight linkages between individual plant species and microbial communities inhabiting the rhizosphere exist, we hypothesized that any differences among plant species specific rhizosphere zones could be observed by shifts in: 1) soil -rhizosphere microbial community structure, 2) enzymatic C:N:P acquisition activities, 3) alterations in the soil C chemistry composition in the rhizosphere, and 4) plant - soil - microbial C:N:P elemental stoichiometry. We selected and grew 4 different C3 grasses species including three species native to the Shortgrass Steppe region (Pascopyrum smithii, Koeleria macrantha, and Vulpia octoflora) and one exotic invasive plant species (B. tectorum) in root-boxes that are designed to allow for easy access to the rhizosphere. The field soil was homogenized using a 4mm sieve and mixed 1:1 with sterile sand and seeded as monocultures (24 replicate root - boxes for each species). Plant and soil samples (along with no - plant control soil samples) were collected on day 28, 78, and 148 (N = 4 /sample period/species). Microbial community structure was quantified using the barcoded pyrosequencing protocols. We measured the potential activity of seven hydrolytic soil enzymes to represent the degradation of C, N, and P-rich substrates. Soil microbial C:N biomass responses to specific plant rhizospheres (MBC and MBN) were measured using the chloroform fumigation extraction method followed by DOC & N analysis. Fourier Transform Infrared Spectroscopy was used to assess differences in plant and soil C chemistry. We found that species specific rhizospheres are characteristic of very different soil chemical, edaphic, and microbial properties. These plant species act as gateways that introduce variability into soil C, N, and P ecosystem functional dynamics directly facilitated by rhizosphere - microbe associations. Our results suggest that nutrient stoichiometry within plant species' rhizospheres is a useful tool for identifying intra-ecosystem functional patterns. By identifying what and how specific species rhizospheres differ among the overall plant community, we can better predict how below-ground microbial community function and subsequent ecosystem processes can be influenced by alterations in plant community shifts based on the rhizosphere effects.

Analysis of black soil environment based on Arduino

NASA Astrophysics Data System (ADS)

Li, Y.; Zhang, Y. F.; Wu, C. H.; Wang, J. F.

2017-05-01

As everyone knows, the black soil of Heilongjiang bred rice is famous in the world. How to use networking technology to detection the growth environment of Heilongjiang rice, and expands it to the local planting environment to our country is the most important topic. However, the growth environment of rice is complex. In current research, some importnat factors such as carbon dioxide, oxygen, temperature and humidity, pH value and microbial content in black soil that affect the growth of plants are selected, and a kind of black land based on data acquisition and transmission system based on the Arduino development environment and the mechanism construction of Kingview has been realized. The collected data was employed to establish the simulation environment for the growth of rice in Heilongjiang. It can be applied to stimulate the rice growing environment of Heilongjiang province, and gives a improvement of rice quality in other areas. Keywords: Arduino; Kingview; living environment

Depth-resolved microbial community analyses in two contrasting soil cores contaminated by antimony and arsenic.

PubMed

Xiao, Enzong; Krumins, Valdis; Xiao, Tangfu; Dong, Yiran; Tang, Song; Ning, Zengping; Huang, Zhengyu; Sun, Weimin

2017-02-01

Investigation of microbial communities of soils contaminated by antimony (Sb) and arsenic (As) is necessary to obtain knowledge for their bioremediation. However, little is known about the depth profiles of microbial community composition and structure in Sb and As contaminated soils. Our previous studies have suggested that historical factors (i.e., soil and sediment) play important roles in governing microbial community structure and composition. Here, we selected two different types of soil (flooded paddy soil versus dry corn field soil) with co-contamination of Sb and As to study interactions between these metalloids, geochemical parameters and the soil microbiota as well as microbial metabolism in response to Sb and As contamination. Comprehensive geochemical analyses and 16S rRNA amplicon sequencing were used to shed light on the interactions of the microbial communities with their environments. A wide diversity of taxonomical groups was present in both soil cores, and many were significantly correlated with geochemical parameters. Canonical correspondence analysis (CCA) and co-occurrence networks further elucidated the impact of geochemical parameters (including Sb and As contamination fractions and sulfate, TOC, Eh, and pH) on vertical distribution of soil microbial communities. Metagenomes predicted from the 16S data using PICRUSt included arsenic metabolism genes such as arsenate reductase (ArsC), arsenite oxidase small subunit (AoxA and AoxB), and arsenite transporter (ArsA and ACR3). In addition, predicted abundances of arsenate reductase (ArsC) and arsenite oxidase (AoxA and AoxB) genes were significantly correlated with Sb contamination fractions, These results suggest potential As biogeochemical cycling in both soil cores and potentially dynamic Sb biogeochemical cycling as well. Copyright © 2016 Elsevier Ltd. All rights reserved.

Occurrence of antibiotics and antibiotic resistance genes in soils from wastewater irrigation areas in the Pearl River Delta region, southern China.

PubMed

Pan, Min; Chu, L M

2018-05-15

The occurrence and distribution of tetracycline (TC) and sulfamethazine (SMZ), and the corresponding antibiotic resistance genes (ARGs) were investigated in six agricultural sites in the Pearl River Delta (PRD) region in southern China. Irrigation water and irrigated soils at two different depths (0-10 and 10-20cm) were analyzed. The total concentrations of TC and SMZ in irrigation water ranged from 69.3 to 234ng/L and from 4.00 to 58.2ng/L, respectively, while the total concentrations of TC and SMZ in irrigated soils ranged from 5.00 to 21.9μg/kg and from 1.30 to 4.20μg/kg, respectively. After long-term irrigation with domestic and fishpond wastewater in the field, the residual TC and SMZ and their corresponding ARGs in soils were significantly higher in fishpond-irrigated soils (Dongguan and Shenzhen) than in domestic wastewater-irrigated soils (Foshan, Guangzhou, Huizhou and Zhongshan). The concentrations of antibiotics and their ARGs were significantly higher in irrigation water than in irrigated soils, which indicated that wastewater was the primary source of antibiotics in the soil environments. The domestic and fishpond wastewater were important repositories of antibiotics and their ARGs, which require effective treatment before their discharge into the environment. Other factors such as soil physicochemical properties, manure application, irrigation water sources and cropping patterns also affect the antibiotic concentrations and ARG abundances. The residual antibiotic concentrations statistically correlated with the corresponding ARGs in irrigation water and irrigated soils, both of which decreased with increasing soil depth, indicating that the concentration of antibiotics in the environment exerted a selection pressure on the microorganisms in the environment. Copyright © 2017 Elsevier B.V. All rights reserved.

The Biotoxicity of Mars Soils

NASA Technical Reports Server (NTRS)

Kerney, Krystal

2010-01-01

Recent evidence from the Opportunity and Spirit rovers suggests that the soils on Mars might be very high in biotoxic materials induding sulfate salts, chlorides, and acidifying agents. Yet, very little is known about how the chemistries of Mars soils might affect the survival and growth of terrestrial microorganisms. The primary objectives of the proposed research will be to: (1) prepare and characterize Mars analog soils amended with potential biotoxic levels of sulfates, chlorides, and acidifying minerals; (2) use the stimulants to conduct a series of toxicology assays to determine if terrestrial microorganisms from spacecraft or extreme environments can survive direct exposure to the biotoxic soils, and (3) mix soils from extreme environments on Earth into Mars analog soils to determine if terrestrial microorganisms can grow and replicate under Martian conditions. The Mars analog soils will be thoroughly characterized by a wide diversity of soil chemistry assays to determine the exact nature of the soluble biotoxic components following hydration. The microbial experiments will be designed to test the effects of Mars stimulants on microbial survival, growth and replication during direct challenge experiments. Toxicology experiments will be designed to mimic terrestrial microbes coming into contact with biotoxic soils with and without liquid water. Results are expected to help" ... characterize the limits of life in ... planetary environments ... " and may help constrain the search for life on Mars.

The Microscopic World of Diatoms

ERIC Educational Resources Information Center

Sultany, Molly; Bixby, Rebecca

2016-01-01

For students in biology, chemistry, or environmental science, diatoms offer excellent insight into watershed health and human impact on the environment. Diatoms are found globally in virtually every habitat that has sunlight and moisture, including polar seas, tropical streams, and on moist soils and mosses. Studying diatoms as biological…

Using Ants To Investigate the Environment.

ERIC Educational Resources Information Center

Hagevik, Rita A.

2003-01-01

Describes three inquiry-based activities designed for students to begin to understand complex environmental relationships in their own backyard. Includes investigations of ants, which allow students to establish a baseline survey of ant fauna, test the importance of ants in nutrient cycling and soil structure maintenances, and increase student…

Fate and transport of radionuclides in soil-water environment. Review.

NASA Astrophysics Data System (ADS)

Konoplev, Aleksei

2017-04-01

The ease in which radionuclides move through the environment and are taken up by plants and animals is governed by their chemical forms and by site-specific environmental characteristics. The objective of this paper is to review basic mechanisms of the behavior of radiocesium and radiostrontium in the environment after the nuclear accident. Our understanding of radionuclide's speciation and migration processes seems to be adequate and explains similarities and differences of radiocesium (r-Cs) behavior in the environment after Fukushima and Chernobyl accidents. Climate and geographical conditions in Fukushima Prefecture of Japan and Chernobyl's near-field zone are obviously different. In particular, precipitation differs substantially, with the annual average for Fukushima being about 3 times higher than at Chernobyl. The landscapes and soils also differ significantly. What is more, the speciation of r-Cs in the releases was distinct (large fraction of radionuclides was deposited as fuel particles in 30-km zone around Chernobyl NPP, while in Fukushima radiocesium is mostly part of condensation particles including glassy hot particles). Radiocesium (r-Cs) in the environment is strongly bound to soil and sediment particles containing micaceous clay minerals (illite, vermiculite, etc.), which is associated with two basic processes - high selective reversible sorption and fixation. The r-Cs distribution coefficient Kd in Fukushima rivers was found to be 1-2 orders of magnitude higher than corresponding values for rivers and surface runoff of Chernobyl area. This is indicative of higher ability of Fukushima soils and sediments to bind r-Cs. Dissolved r-Cs wash-off for Fukushima river watersheds is essentially slower than those for Chernobyl. However, steeper slopes and higher precipitation in Fukushima area cause higher erosion and higher particulate r-Cs wash-off. For a comparable time after the accident the total r-Cs wash-off from contaminated catchments in Fukushima is up to one order of magnitude higher than in Chernobyl. Long-term dynamics of radionuclide concentrations in rivers is approached from the standpoint of basic mechanisms of radionuclide sorption-desorption, fixation, vertical migration in catchment soils. Corresponding semi-empirical models are presented and discussed. For the Chernobyl case, radiostrontium (r-Sr) was shown to be more mobile and moving faster in dissolved state with surface runoff and river water in comparison with r-Cs. Similar pattern was observed for Mayak area in South Ural (Russia), where r-Sr was traced up to 1500 km away from the release point migrating through Techa-Iset'-Tobol-Irtysh-Ob' river system. On the other hand, r-Cs bound to clay particles settles down in Techa river reservoirs and is transported with river water only insignificantly. For the first 3 years after the accident vertical migration of r-Cs in soils of Fukushima catchments was found to be faster than in Chernobyl due to higher air temperature, higher precipitation and higher biological activity in top soil. However, with time this process slows down because of higher r-Cs retardation in Fukushima soils. In Fukushima case, extreme floods during typhoons lead to substantial reduction in dose rate on floodplain areas due to sedimentation of relatively clean material and burial of contaminated top soil layer. In general, due to higher precipitation, higher temperatures and higher biological activities in soils, self-purification of the environment and natural attenuation in Fukushima is essentially faster than in Chernobyl area.

Environmentally induced, occupational diseases with emphasis on chronic kidney disease of multifactorial origin affecting tropical countries.

PubMed

Wimalawansa, Shehani A; Wimalawansa, Sunil J

2016-01-01

Environmentally induced, occupational diseases are increasing worldwide, especially in rural agricultural communities. Poverty-associated malnutrition, environmental hazards and pollution, and lack of access to clean water, safe sanitation, and modern healthcare facilities are often associated with these chronic illnesses. The authors systematically reviewed occupational public health issues that have been related to the environment. General interpretations of results were included as per the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Pertinent publications from research databases were reviewed on (A) the risk-benefits, (B) the prevalence of risk factors for various diseases, (C) the benefits of not ignoring the risk factors (i.e., broader evidence), and (D) the risks, effects, and outcomes of different types of interventions. The authors used chronic kidney disease of multifactorial origin (CKDmfo) as an example to explore the theme. Emphasis was given to the regions with emerging economies and developing countries located in the vicinity of the equator. Geographical, socio-economic and aetiological similarities exist for many chronic non-communicable diseases that are affecting tropical countries around the equator. The authors identified manufacturing, mining, and agriculture as the biggest polluters of the environment. In addition, deforestation and associated soil erosion, overuse of agrochemicals, and irresponsible factory discharge (e.g., chemicals and paint, from rubber and textile factories, etc.), all contribute to pollution. To decrease the escalating incidences of environmentally induced diseases, governments should work proactively to protect the environment, especially watersheds, and take steps to minimise harmful occupational exposures and strictly enforce environmental regulations. Creating public awareness of environmental issues and their relationship to public health is essential. This includes regular monitoring and periodic publication of the quality of water, air and soil; preventing deforestation and man-made soil erosion, increasing forest and ground cover, preventing occupational injuries, judicious and safe use of agrochemicals, sustainable agriculture and development programs, and implementing legislation to protect and conserve water heriage and the environment. These actions are essential both for a healthier environment and for the health of the people who live in that environment. Such measures would also decrease public health threats from such, including global-warming-related erratic environmental changes and the occurrence and the spread of non-communicable diseases, such as CKDmfo.

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.

Connecting Returned Apollo Soils and Remote Sensing: Application to the Diviner Lunar Radiometer

NASA Technical Reports Server (NTRS)

Greenhagen, B. T.; DonaldsonHanna, K. L.; Thomas, I. R.; Bowles, N. E.; Allen, Carlton C.; Pieters, C. M.; Paige, D. A.

2014-01-01

The Diviner Lunar Radiometer, onboard NASA's Lunar Reconnaissance Orbiter, has produced the first global, high resolution, thermal infrared observations of an airless body. The Moon, which is the most accessible member of this most abundant class of solar system objects, is also the only body for which we have extraterrestrial samples with known spatial context, returned Apollo samples. Here we present the results of a comprehensive study to reproduce an accurate simulated lunar environment, evaluate the most appropriate sample and measurement conditions, collect thermal infrared spectra of a representative suite of Apollo soils, and correlate them with Diviner observations of the lunar surface. It has been established previously that thermal infrared spectra measured in simulated lunar environment (SLE) are significantly altered from spectra measured under terrestrial or martian conditions. The data presented here were collected at the University of Oxford Simulated Lunar Environment Chamber (SLEC). In SLEC, we simulate the lunar environment by: (1) pumping the chamber to vacuum pressures (less than 10-4 mbar) sufficient to simulate lunar heat transport processes within the sample, (2) cooling the chamber with liquid nitrogen to simulate radiation to the cold space environment, and (3) heating the samples with heaters and lamp to set-up thermal gradients similar to those experienced in the upper hundreds of microns of the lunar surface. We then conducted a comprehensive suite of experiments using different sample preparation and heating conditions on Apollo soils 15071 (maria) and 67701 (highland) and compared the results to Diviner noontime data to select the optimal experimental conditions. This study includes thermal infrared SLE measurements of 10084 (A11 - LM), 12001 (A12 - LM), 14259 (A14 - LM), 15071 (A15 - S1), 15601 (A15 - S9a), 61141 (A16 - S1), 66031 (A16 - S6), 67701 (A16 - S11), and 70181 (A17 - LM). The Diviner dataset includes all six Apollo sites at approximately 200 m spatial resolution We find that analyses of Diviner observations of individual sampling stations and SLE measurements returned Apollo soils show good agreement, while comparisons to thermal infrared reflectance under ambient conditions do not agree well, which underscores the need for SLE measurements and validates the Diviner compositional measurement technique.

Forest Soil Bacteria: Diversity, Involvement in Ecosystem Processes, and Response to Global Change

PubMed Central

Lladó, Salvador; López-Mondéjar, Rubén

2017-01-01

SUMMARY The ecology of forest soils is an important field of research due to the role of forests as carbon sinks. Consequently, a significant amount of information has been accumulated concerning their ecology, especially for temperate and boreal forests. Although most studies have focused on fungi, forest soil bacteria also play important roles in this environment. In forest soils, bacteria inhabit multiple habitats with specific properties, including bulk soil, rhizosphere, litter, and deadwood habitats, where their communities are shaped by nutrient availability and biotic interactions. Bacteria contribute to a range of essential soil processes involved in the cycling of carbon, nitrogen, and phosphorus. They take part in the decomposition of dead plant biomass and are highly important for the decomposition of dead fungal mycelia. In rhizospheres of forest trees, bacteria interact with plant roots and mycorrhizal fungi as commensalists or mycorrhiza helpers. Bacteria also mediate multiple critical steps in the nitrogen cycle, including N fixation. Bacterial communities in forest soils respond to the effects of global change, such as climate warming, increased levels of carbon dioxide, or anthropogenic nitrogen deposition. This response, however, often reflects the specificities of each studied forest ecosystem, and it is still impossible to fully incorporate bacteria into predictive models. The understanding of bacterial ecology in forest soils has advanced dramatically in recent years, but it is still incomplete. The exact extent of the contribution of bacteria to forest ecosystem processes will be recognized only in the future, when the activities of all soil community members are studied simultaneously. PMID:28404790

Forest Soil Bacteria: Diversity, Involvement in Ecosystem Processes, and Response to Global Change.

PubMed

Lladó, Salvador; López-Mondéjar, Rubén; Baldrian, Petr

2017-06-01

The ecology of forest soils is an important field of research due to the role of forests as carbon sinks. Consequently, a significant amount of information has been accumulated concerning their ecology, especially for temperate and boreal forests. Although most studies have focused on fungi, forest soil bacteria also play important roles in this environment. In forest soils, bacteria inhabit multiple habitats with specific properties, including bulk soil, rhizosphere, litter, and deadwood habitats, where their communities are shaped by nutrient availability and biotic interactions. Bacteria contribute to a range of essential soil processes involved in the cycling of carbon, nitrogen, and phosphorus. They take part in the decomposition of dead plant biomass and are highly important for the decomposition of dead fungal mycelia. In rhizospheres of forest trees, bacteria interact with plant roots and mycorrhizal fungi as commensalists or mycorrhiza helpers. Bacteria also mediate multiple critical steps in the nitrogen cycle, including N fixation. Bacterial communities in forest soils respond to the effects of global change, such as climate warming, increased levels of carbon dioxide, or anthropogenic nitrogen deposition. This response, however, often reflects the specificities of each studied forest ecosystem, and it is still impossible to fully incorporate bacteria into predictive models. The understanding of bacterial ecology in forest soils has advanced dramatically in recent years, but it is still incomplete. The exact extent of the contribution of bacteria to forest ecosystem processes will be recognized only in the future, when the activities of all soil community members are studied simultaneously. Copyright © 2017 American Society for Microbiology.

Nitrification rates in Arctic soils are associated with functionally distinct populations of ammonia-oxidizing archaea

NASA Astrophysics Data System (ADS)

Alves, Ricardo J. E.; Wanek, Wolfgang; Zappe, Anna; Richter, Andreas; Svenning, Mette M.; Schleper, Christa; Urich, Tim

2014-05-01

The functioning of Arctic soil ecosystems is crucially important for global climate, although basic knowledge regarding their biogeochemical processes is lacking. Nitrogen (N) is the major limiting nutrient in these environments, and therefore it is particularly important to gain a better understanding of the microbial populations catalyzing transformations that influence N bioavailability. However, microbial communities driving this process remain largely uncharacterized in Arctic soils, namely those catalyzing the rate-limiting step of ammonia (NH3) oxidation. Eleven Arctic soils from Svalbard were analyzed through a polyphasic approach, including determination of gross nitrification rates through a 15N pool dilution method, qualitative and quantitative analyses of ammonia-oxidizing archaea (AOA) and bacteria (AOB) populations based on the functional marker gene amoA (encoding the ammonia monooxygenase subunit A), and enrichment of AOA in laboratory cultures. AOA were the only NH3 oxidizers detected in five out of 11 soils, and outnumbered AOB by 1 to 3 orders of magnitude in most others. AOA showed a great overall phylogenetic diversity that was differentially distributed across soil ecosystems, and exhibited an uneven population composition that reflected the dominance of a single AOA phylotype in each population. Moreover, AOA populations showed a multifactorial association with the soil properties, which reflected an overall distribution associated with tundra type and with several physico-chemical parameters combined, namely pH and soil moisture and N contents (i.e., NO3- and dissolved organic N). Remarkably, the different gross in situ and potential nitrification rates between soils were associated with distinct AOA phylogenetic clades, suggesting differences in their nitrifying potential, both under the native NH3 conditions and as a response to higher NH3 availability. This was further supported by the selective enrichment of two AOA clades that exhibited different NH3 oxidation rates. In addition, the enrichment cultures provided the first direct evidence for NH3 oxidation by an AOA from an uncharacterized Thaumarchaeota-AOA lineage. Our results indicate that AOA are functionally heterogeneous, and that the selection of distinct AOA populations by the environment can be determinant for nitrification activity and N availability in soils. Furthermore, our observations emphasize the fact that, disturbances in populations of specific microbial functional groups, such as nitrifiers, constitute potential response mechanisms to environmental changes. These findings are not only relevant for Arctic environments, but have implications for the role of AOA in nitrification in all soils.

The history of soil erosion: Interpreting historical sources, buried soils and colluvial sediments as archives of past soil erosion and human-environment interactions in the Longue Durée

NASA Astrophysics Data System (ADS)

Dotterweich, Markus

2015-04-01

Soil erosion threatens the environment and the sustainability of agricultural practices since the earliest societies started modifying their natural environment in the Neolithic. Almost all farming-based cultures in the world, from large civilizations to peasant groups on little islands, have suffered from soil erosion by water. The amounts of soil erosion varied largely through time and space, and extreme events have left a wide variety of imprints on the landscape over millennia. Eroded hillslopes and gullies, deposited sediments in sinks like lakes, footslopes, valleys, floodplains, and river deltas are geomorphic legacies that have been linked to changes in land use and climate by many studies during the last decades. However, a standardized analysis and interpretation of these geomorphic legacies is problematic because of the variety of methodological approaches and the nonlinearity between soil erosion, climate, and land use. Cascading effects, land use structures, soil management, soil conservation strategies, and long-term system changes have produced different signals over time. Historical records are crucial and an invaluable source to provide alternative proxies about soil erosion in the past. Direct observations of individual soil erosion events may restrict the deposition of a distinct sediment package to a certain time span. They also expand the range of alternative interpretations, particularly with respect to the long-term effects of soil erosion to ecosystem services and socioeconomic processes. However, historical records also need critical analyses regarding their origin, intention, and quality. They were often created in the context of personal interests or political issues rather than being based on scientific facts; and it is often unclear if they represent certain events, narratives, or vague assumptions. This presentation will present and discuss examples of geomorphic evidences and historical records of past soil erosion for the deciphering of human-environment interactions in the Longue Durée.

The Past, Present, and Future of Soils and Human Health Studies

NASA Astrophysics Data System (ADS)

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

2012-04-01

The idea that human health is tied to the soil is not a new one. As far back as approximately 1400 B.C. the Bible depicts Moses as understanding that fertile soil was essential to the well-being of his people. While exploring Canaan, Moses charged the men he sent to evaluate the fertility of the soil. In 400 B.C. the Greek philosopher Hippocrates provided a list of things that should be considered in a proper medical evaluation, including the ground. By the late 1700 and early 1800s, American farmers had recognized that soil properties had some connection to human health. In "Letters from an American Farmer", published in 1792, J. Hector St. John De Crèvecoeur stated "Men are like plants; the goodness and flavor of the fruit proceeds from the peculiar soil and exposition in which they grow". And in "Larding the Lean Earth", published in 2002, S. Stoll noted that North American farmers in the early 1800s recognized a link between an enduring agriculture and an enduring society, leading them to become concerned about the fertility of their soils and to seek ways of improving the soil in order to insure a healthy society. Continuing into the first half of the 20th Century, a 1940 publication by the International Harvester Company noted that poor soils lead to "stoop-shouldered, poverty-stricken people." Then, in 1947, Sir Albert Howard published his landmark work "The Soil and Health: A Study of Organic Agriculture", a work that took a critical look at modern production agriculture and at the link between soil fertility and health. Despite these various lines of evidence of some earlier level of understanding that healthy soils are required for healthy people, the scientific study of the relationship between soils and human health is a fairly new undertaking. In his 1997 work "Soil and Human Health: A Review", M.A. Oliver states "… there is a dearth of quantitative information on the relations between elements in the soil and human health;…there is much speculation and anecdotal evidence." So, the scientific study of soils and human health is a recent undertaking, but the idea that healthy soils are required for healthy people is not a particularly new one. 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 web 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 we need to get a better understanding of. Future successes in soils and human health research will require effectively addressing difficult issues such as these.

Bioenergy cropping systems that incorporate native grasses stimulate growth of plant-associated soil microbes in the absence of nitrogen fertilization

DOE PAGES

Oates, Lawrence G.; Duncan, David S.; Sanford, Gregg R.; ...

2016-10-03

The choice of crops and their management can strongly influence soil microbial communities and their processes. Here, we used lipid biomarker profiling to characterize how soil microbial composition of five potential bioenergy cropping systems diverged from a common baseline five years after they were established. The cropping systems we studied included an annual system (continuous no-till corn) and four perennial crops (switchgrass, miscanthus, hybrid poplar, and restored prairie). Partial- and no-stover removal were compared for the corn system, while N-additions were compared to unfertilized plots for the perennial cropping systems. Arbuscular mycorrhizal fungi (AMF) and Gram-negative biomass was higher inmore » unfertilized perennial grass systems, especially in switchgrass and prairie. Gram-positive bacterial biomass decreased in all systems relative to baseline values in surface soils (0–10 cm), but not subsurface soils (10–25 cm). Overall microbial composition was similar between the two soil depths. Our findings demonstrate the capacity of unfertilized perennial cropping systems to recreate microbial composition found in undisturbed soil environments and indicate how strongly agroecosystem management decisions such as N addition and plant community composition can influence soil microbial assemblages.« less

Bioenergy cropping systems that incorporate native grasses stimulate growth of plant-associated soil microbes in the absence of nitrogen fertilization

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

Oates, Lawrence G.; Duncan, David S.; Sanford, Gregg R.

The choice of crops and their management can strongly influence soil microbial communities and their processes. Here, we used lipid biomarker profiling to characterize how soil microbial composition of five potential bioenergy cropping systems diverged from a common baseline five years after they were established. The cropping systems we studied included an annual system (continuous no-till corn) and four perennial crops (switchgrass, miscanthus, hybrid poplar, and restored prairie). Partial- and no-stover removal were compared for the corn system, while N-additions were compared to unfertilized plots for the perennial cropping systems. Arbuscular mycorrhizal fungi (AMF) and Gram-negative biomass was higher inmore » unfertilized perennial grass systems, especially in switchgrass and prairie. Gram-positive bacterial biomass decreased in all systems relative to baseline values in surface soils (0–10 cm), but not subsurface soils (10–25 cm). Overall microbial composition was similar between the two soil depths. Our findings demonstrate the capacity of unfertilized perennial cropping systems to recreate microbial composition found in undisturbed soil environments and indicate how strongly agroecosystem management decisions such as N addition and plant community composition can influence soil microbial assemblages.« less

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.

Interactive Effects of Moss-Dominated Crusts and Artemisia ordosica on Wind Erosion and Soil Moisture in Mu Us Sandland, China

PubMed Central

Yang, Yongsheng; Bu, Chongfeng; Mu, Xingmin; Shao, Hongbo; Zhang, Kankan

2014-01-01

To better understand the effects of biological soil crusts (BSCs) on soil moisture and wind erosion and study the necessity and feasibility of disturbance of BSCs in the Mu Us sandland, the effects of four treatments, including moss-dominated crusts alone, Artemisia ordosica alone, bare sand, and Artemisia ordosica combined with moss-dominated crusts, on rainwater infiltration, soil moisture, and annual wind erosion were observed. The major results are as follows. (1) The development of moss-dominated crusts exacerbated soil moisture consumption and had negative effects on soil moisture in the Mu Us sandland. (2) Moss-dominated crusts significantly increased soil resistance to wind erosion, and when combined with Artemisia ordosica, this effect became more significant. The contribution of moss-dominated crusts under Artemisia ordosica was significantly lower than that of moss-dominated crusts alone in sites where vegetative coverage > 50%. (3) Finally, an appropriate disturbance of moss-dominated crusts in the rainy season in sites with high vegetative coverage improved soil water environment and vegetation succession, but disturbance in sites with little or no vegetative cover should be prohibited to avoid the exacerbation of wind erosion. PMID:24982973

Interactive effects of moss-dominated crusts and Artemisia ordosica on wind erosion and soil moisture in Mu Us sandland, China.

PubMed

Yang, Yongsheng; Bu, Chongfeng; Mu, Xingmin; Shao, Hongbo; Zhang, Kankan

2014-01-01

To better understand the effects of biological soil crusts (BSCs) on soil moisture and wind erosion and study the necessity and feasibility of disturbance of BSCs in the Mu Us sandland, the effects of four treatments, including moss-dominated crusts alone, Artemisia ordosica alone, bare sand, and Artemisia ordosica combined with moss-dominated crusts, on rainwater infiltration, soil moisture, and annual wind erosion were observed. The major results are as follows. (1) The development of moss-dominated crusts exacerbated soil moisture consumption and had negative effects on soil moisture in the Mu Us sandland. (2) Moss-dominated crusts significantly increased soil resistance to wind erosion, and when combined with Artemisia ordosica, this effect became more significant. The contribution of moss-dominated crusts under Artemisia ordosica was significantly lower than that of moss-dominated crusts alone in sites where vegetative coverage > 50%. (3) Finally, an appropriate disturbance of moss-dominated crusts in the rainy season in sites with high vegetative coverage improved soil water environment and vegetation succession, but disturbance in sites with little or no vegetative cover should be prohibited to avoid the exacerbation of wind erosion.

Diel hysteresis between soil respiration and soil temperature in a biological soil crust covered desert ecosystem

PubMed Central

Li, Xinrong; Zhang, Peng; Chen, Yongle

2018-01-01

Soil respiration induced by biological soil crusts (BSCs) is an important process in the carbon (C) cycle in arid and semi-arid ecosystems, where vascular plants are restricted by the harsh environment, particularly the limited soil moisture. However, the interaction between temperature and soil respiration remains uncertain because of the number of factors that control soil respiration, including temperature and soil moisture, especially in BSC-dominated areas. In this study, the soil respiration in moss-dominated crusts and lichen-dominated crusts was continuously measured using an automated soil respiration system over a one-year period from November 2015 to October 2016 in the Shapotou region of the Tengger Desert, northern China. The results indicated that over daily cycles, the half-hourly soil respiration rates in both types of BSC-covered areas were commonly related to the soil temperature. The observed diel hysteresis between the half-hourly soil respiration rates and soil temperature in the BSC-covered areas was limited by nonlinearity loops with semielliptical shapes, and soil temperature often peaked later than the half-hourly soil respiration rates in the BSC-covered areas. The average lag times between the half-hourly soil respiration rates and soil temperature for both types of BSC-covered areas were two hours over the diel cycles, and they were negatively and linearly related to the volumetric soil water content. Our results highlight the diel hysteresis phenomenon that occurs between soil respiration rates and soil temperatures in BSC-covered areas and the negative response of this phenomenon to soil moisture, which may influence total C budget evaluations. Therefore, the interactive effects of soil temperature and moisture on soil respiration in BSC-covered areas should be considered in global carbon cycle models of desert ecosystems. PMID:29624606

Screening and Characterization of Potentially Suppressive Soils against Gaeumannomyces graminis under Extensive Wheat Cropping by Chilean Indigenous Communities

PubMed Central

Durán, Paola; Jorquera, Milko; Viscardi, Sharon; Carrion, Victor J.; Mora, María de la Luz; Pozo, María J.

2017-01-01

Wheat production around the world is severely compromised by the occurrence of “take-all” disease, which is caused by the soil-borne pathogen Gaeumannomyces graminis var. tritici (Ggt). In this context, suppressive soils are those environments in which plants comparatively suffer less soil-borne pathogen diseases than expected, owing to native soil microorganism activities. In southern Chile, where 85% of the national cereal production takes place, several studies have suggested the existence of suppressive soils under extensive wheat cropping. Thus, this study aimed to screen Ggt-suppressive soil occurrence in 16 locations managed by indigenous “Mapuche” communities, using extensive wheat cropping for more than 10 years. Ggt growth inhibition in vitro screenings allowed the identification of nine putative suppressive soils. Six of these soils, including Andisols and Ultisols, were confirmed to be suppressive, since they reduced take-all disease in wheat plants growing under greenhouse conditions. Suppressiveness was lost upon soil sterilization, and recovered by adding 1% of the natural soil, hence confirming that suppressiveness was closely associated to the soil microbiome community composition. Our results demonstrate that long-term extensive wheat cropping, established by small Mapuche communities, can generate suppressive soils that can be used as effective microorganism sources for take-all disease biocontrol. Accordingly, suppressive soil identification and characterization are key steps for the development of environmentally-friendly and efficient biotechnological applications for soil-borne disease control. PMID:28861064

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.

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.

Soil manganese redox cycling in suboxic zones: Effects on soil carbon stability

EPA Science Inventory

Suboxic soil environments contain a disproportionately higher concentration of highly reactive free radicals relative to the surrounding soil matrix, which may have significant implications for soil organic matter cycling and stabilization. This study investigated how Mn-ozidizin...

[Effects of intercropping Chinese onion cultivars of different allelopathic potential on cucumber growth and soil micro-environment].

PubMed

Yang, Yang; Wu, Feng-zhi

2011-10-01

A pot experiment was conducted to study the effects of intercropping various Chinese onion cultivars of different allelopathic potential on the cucumber growth and rhizospheric soil environment. When intercropped with high allelopathic Chinese onion cultivars, the EC value and peroxidase activity of cucumber rhizospheric soil decreased, while the pH value, invertase and catalase activities, and bacterial community diversity increased. The cloning and sequencing results indicated that most DGGE bands amplified from cucumber rhizospheric soil samples showed a high homology to uncultured bacterial species. The common bands were affiliated with Actinobacteria and Proteobacteria, and the differential bacteria bands were affiliated with Proteobacteria and Anaerolineaceae. Rhodospirillales and Acidobacteria were only found in the cucumber rhizospheric soil intercropped with low allelopathic Chinese onion cultivars. Correlation analysis showed that there were significant positive correlations between rhizospheric soil urease activity and cucumber seedlings height, total dry biomass, leaf area, and DGGE band number. It was suggested that intercropping high allelopathic Chinese onion cultivars could establish a good rhizospheric soil micro-environment for cucumber growth, and promote the growth of cucumber seedlings markedly.

Soil nutrients, bacterial communities, and veterinary pharmaceuticals in beef cattle backgrounding confinement on karst environment

USDA-ARS?s Scientific Manuscript database

The United States hosts the world’s largest grain fed beef production. Commercial beef production in the US consists of three tiers that include: cow-calf enterprises, cattle backgrounding/stockering, and feedlot finishing. Beef cattle backgrounding/stockering represents an intermediate between the ...

Life cycle analysis of biochar [Chapter 3

Treesearch

Richard D. Bergman; Hongmei Gu; Deborah S. Page-Dumroese; Nathaniel M. Anderson

2017-01-01

All products, including bioproducts, have an impact on the environment by consuming resources and releasing emissions during their production. Biochar, a bioproduct, has received considerable attention because of its potential to sequester carbon in soil while enhancing productivity, thus aiding sustainable supply chain development. In this chapter, the environmental...

Network analysis: a new tool for resource managers

Treesearch

Ruth H. Allen

1980-01-01

Resource managers manipulate ecosystems for direct or indirect human uses. Examples of relatively well studied resource management issues include familiar biological products such as: forests, ranges, fish and wildlife; or physical products such as air, water and soil. Until very recently, urban environments received much less scholarly attention. However, as Spurr (...

High Sensitivity NMR and Mixture Analysis for Nematode Behavioral Metabolomics

USDA-ARS?s Scientific Manuscript database

Nematodes are the most abundant animal on earth, and they parasitize virtually all plants and animals. Caenorhabditis elegans is a free-living nematode that lives in soil and composting material. We have shown that C. elegans releases at least 40 small molecules into its environment including many...

Fruit metabolite networks in engineered and non-engineered tomato genotypes reveal fluidity in a hormone and agroecosystem specific manner

USDA-ARS?s Scientific Manuscript database

Multiple strategies have been explored throughout the world to meet food security. These include molecular breeding, transgenic genotype development, reduced-tillage crop production, modification of the soil environment with cover crops or polyethylene mulches and tunnels, and organic farming. Unde...

Extracellular metabolites limit bacterial susceptibility to predation in a protist-specific manner and their regulation may be protist-induced

USDA-ARS?s Scientific Manuscript database

Bacteria employ various strategies to evade protozoan predation, including production and release of bioactive compounds. This capability may be instrumental in determining bacterial resistance to protozoan grazing, thereby enhancing survival of producing strains in soil environments. A limited numb...

Geospatial technology applications in forest hydrology

Treesearch

S.S. Panda; E. Masson; S. Sen; H.W. Kim; Devendra Amatya

2016-01-01

Two separate disciplines, hydrology and forestry, together constitute forest hydrology. It is obvious that forestry and forest hydrology disciplines are spatial entities. Forestry is the science that seeks to understand the nature of forests throygh their life cycle and interactions with the surrounding environment. Forest hydrology includes forest soil water, streams...

PARTIAL LEAST SQUARE ANALYSES FOR ASSOCIATION OF LANDSCAPE METRICS WITH WATER BIOLOGICAL AND CHEMICAL PROPERTIES IN THE SAVANNAH RIVER BASIN

EPA Science Inventory

Surface water quality is related to conditions in the surrounding geophysical environment, including soils, landcover, and anthropogenic activities. A number of statistical methods may be used to analyze and explore relationships among variables. Single-, multiple- and multivaria...

Nonmarket resource valuation in the postfire environment

Treesearch

David Calkin; Greg Jones; Kevin Hyde

2008-01-01

After the containment of large wildland fires, major onsite and downstream effects including lost soil productivity, watershed response, increased vulnerability to invasive weeds, and downstream sedimentation can cause threats to human life and property. Burned Area Emergency Response (BAER) teams are responsible for developing treatment plans to mitigate negative...

Evaluation of the impact of lime softening waste disposal in natural environments

EPA Science Inventory

Drinking water treatment residues (WTR), generated from the lime softening processes, are commonly reused or disposed of in a number of applications; these include use as a soil amendment or a subsurface fill. Recently questions were posed by the Florida regulatory community on w...

Impacts of corn residue grazing and baling on wind erosion potential in a semiarid environment

USDA-ARS?s Scientific Manuscript database

Implications of corn (Zea mays L.) residue grazing and baling on wind erosion in integrated crop-livestock systems are not well understood. We studied: 1) soil properties affecting wind erosion potential including dry aggregate-size distribution, geometric mean diameter (GMDA), geometric standard de...

Research in remote sensing of agriculture, earth resources, and man's environment

NASA Technical Reports Server (NTRS)

Landgrebe, D. A.

1975-01-01

Progress is reported for several projects involving the utilization of LANDSAT remote sensing capabilities. Areas under study include crop inventory, crop identification, crop yield prediction, forest resources evaluation, land resources evaluation and soil classification. Numerical methods for image processing are discussed, particularly those for image enhancement and analysis.

A cost effective bioremediation strategy using low technology resources for reclamation of dry land hydrocarbon contamination: A case study

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

Robb, A.J. III; Hoggatt, P.R.

Hydrocarbon containing soil was bioremediated at a combination wastewater and slop oil skim evaporation pond utilizing cost effective low technology resources. Fluids and sludge from the football field-sized pond were extraction procedure toxicity and purgeable organics tested, and total petroleum hydrocarbon (TPH) concentrations determined. An impact risk analysis was performed, and a corrective action plan developed and implemented. The three year project was closely coordinated with the Kansas Corporation Commission (KCC) and the Kansas Department of Health and Environment (KDHE) who established the closure level. The impacted soils at the pond were completely excavated and closure was immediately granted bymore » KDHE for the excavated area. The 24,000 cubic yards of excavated soil were then surface spread on adjacent Mobil property. A nutrient and microbial base was applied to bioaugment the soil. The preapplication land surface and the subsequently land farmed soil was periodically disced and chiseled. A job safety plan including industrial hygiene measures to eliminate workforce exposure was developed and implemented. The final remediation cost analysis amounts to $1.48 per cubic yard compared to the $30 to $150 per cubic yard industry o estimates for similar projects. Several factors were critical in ailing costs to remain so low: (1) assessment and implementation by local in-house staff, (2) conservative remedial action plan and sampling strategy; (3) local contractors; (4) locally available soil amendment; and (5) effective regulatory coordination. The methods described can be used to cost effectively characterize and bioremediate other sites where hydrocarbon-impacted soils exist in similar dry-land environments.« less

Heavy metal pollution in farmland irrigated with river water near a steel plant—magnetic and geochemical signature

NASA Astrophysics Data System (ADS)

Zhang, Chunxia; Appel, Erwin; Qiao, Qingqing

2013-03-01

The presence of heavy metals (HMs) in the environment is a major threat for humans. Magnetic proxies provide a rapid method for assessing the degree of HM pollution in environment. We have studied farmland soil irrigated with polluted river water in the vicinity of a steel plant in Loudi city (Hunan Province, China) to test the efficiency of magnetic methods for detecting the degree of HM pollution. Both magnetic and non-magnetic (microscopic, chemical and statistical) methods were used to characterize these farmland soils. Enhanced magnetic concentration values were found in the upper arable soil horizon (0-20 cm), which is related to the presence of spherical ˜10 to 30 μm sized magnetite particles. The spatial distribution of magnetic concentration and HM contents in the farmland soils matches with the spatial pattern of these parameters in river sediments. These findings provide evidence that HM pollution of the farmland soil is mainly caused by irrigation with wastewater. HMs Zn, Pb, Cu, Cd, Co, Ni, V are well correlate with magnetic susceptibility (χ). The pollution load index (PLI) of all nine anthropogenic HMs (including also Cr and Mo) and log10(χ) are significantly correlated. Using the resulting linear PLI-log10(χ) function, values of χ can serve as a convenient tool for semi-quantifying the degree of HM pollution in the uppermost ˜20 cm of the studied farmland soils. These findings suggest that magnetic methods can generally serve as a convenient tool for detecting and mapping HM pollution in farmland soil irrigated with wastewater from sites nearby heavy industrial activities.

Changes in soil organic carbon fractions following remediation of a degraded coastal floodplain wetland

NASA Astrophysics Data System (ADS)

Wong, Vanessa; McNaughton, Caitlyn; Pearson, Amy

2017-04-01

Coastal floodplain soils and wetland sediments can store large amounts of soil organic carbon (SOC). These environments are also commonly underlain by sulfidic sediments which can oxidise, largely due to drainage of floodplains to decrease water levels, to form coastal acid sulfate soils (CASS). Following oxidation, pH of both soil and water decrease, and acidity and mobilisation of trace metals increases to adversely affect vegetation and adjacent aquatic ecosystems. In extreme cases, vegetation death occurs resulting in the formation of scalds, which are large bare patches. Remediation of these degraded coastal soils generally involves neutralisation of acidity via application of lime and the re-introduction of anoxic conditions by raising water levels. Our understanding of the geochemical changes which occur as a result of remediation is relatively well established. However, SOC stocks and fractions have not been quantified in these coastal floodplain environments. We studied the changes in soil geochemistry and SOC stocks and fractions three years after remediation of a degraded and scalded coastal floodplain. Remediation treatments included raising water levels, and addition of either lime (LO) or lime and mulch (LM) relative to a control (C) site. We found SOC concentrations in the remediated sites (LO and LM) were more than double than that found at site C, reflected in the higher SOC stocks to a depth of 1.6 m. The particulate organic C fraction was higher at sites LO and LM due to increased vegetation and biomass inputs, compared to site C. Therefore, coastal floodplains and wetlands are a large store of SOC and can potentially increase SOC following remediation due to i) reduced decomposition rates with higher water levels and waterlogging, and ii) high C inputs due to rapid revegetation of scalded areas and high rates of biomass production.

Spatial variation in soil biota mediates plant adaptation to a foliar pathogen.

PubMed

Mursinoff, Sini; Tack, Ayco J M

2017-04-01

Theory suggests that below-ground spatial heterogeneity may mediate host-parasite evolutionary dynamics and patterns of local adaptation, but this has rarely been tested in natural systems. Here, we test experimentally for the impact of spatial variation in the abiotic and biotic soil environment on the evolutionary outcome of the interaction between the host plant Plantago lanceolata and its specialist foliar pathogen Podosphaera plantaginis. Plants showed no adaptation to the local soil environment in the absence of natural enemies. However, quantitative, but not qualitative, plant resistance against local pathogens was higher when plants were grown in their local field soil than when they were grown in nonlocal field soil. This pattern was robust when extending the spatial scale beyond a single region, but disappeared with soil sterilization, indicating that soil biota mediated plant adaptation. We conclude that below-ground biotic heterogeneity mediates above-ground patterns of plant adaptation, resulting in increased plant resistance when plants are grown in their local soil environment. From an applied perspective, our findings emphasize the importance of using locally selected seeds in restoration ecology and low-input agriculture. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

Diversity and natural functions of antibiotics produced by beneficial and plant pathogenic bacteria.

PubMed

Raaijmakers, Jos M; Mazzola, Mark

2012-01-01

Soil- and plant-associated environments harbor numerous bacteria that produce antibiotic metabolites with specific or broad-spectrum activities against coexisting microorganisms. The function and ecological importance of antibiotics have long been assumed to yield a survival advantage to the producing bacteria in the highly competitive but resource-limited soil environments through direct suppression. Although specific antibiotics may enhance producer persistence when challenged by competitors or predators in soil habitats, at subinhibitory concentrations antibiotics exhibit a diversity of other roles in the life history of the producing bacteria. Many processes modulated by antibiotics may be inherently critical to the producing bacterium, such as the acquisition of substrates or initiation of developmental changes that will ensure survival under stressful conditions. Antibiotics may also have roles in more complex interactions, including in virulence on host plants or in shaping the outcomes of multitrophic interactions. The innate functions of antibiotics to producing bacteria in their native ecosystem are just beginning to emerge, but current knowledge already reveals a breadth of activities well beyond the historical perspective of antibiotics as weaponry in microbial conflicts.

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

Suresh, Niraj; Stephens, Sean A.; Adams, Lexor

Plant roots play a critical role in plant-soil-microbe interactions that occur in the rhizosphere, as well as processes with important implications to climate change and forest management. Quantitative size information on roots in their native environment is invaluable for studying root growth and environmental processes involving the plant. X ray computed tomography (XCT) has been demonstrated to be an effective tool for in situ root scanning and analysis. Our group at the Environmental Molecular Sciences Laboratory (EMSL) has developed an XCT-based tool to image and quantitatively analyze plant root structures in their native soil environment. XCT data collected on amore » Prairie dropseed (Sporobolus heterolepis) specimen was used to visualize its root structure. A combination of open-source software RooTrak and DDV were employed to segment the root from the soil, and calculate its isosurface, respectively. Our own computer script named 3DRoot-SV was developed and used to calculate root volume and surface area from a triangular mesh. The process utilizing a unique combination of tools, from imaging to quantitative root analysis, including the 3DRoot-SV computer script, is described.« less

FDR Soil Moisture Sensor for Environmental Testing and Evaluation

NASA Astrophysics Data System (ADS)

Linmao, Ye; longqin, Xue; guangzhou, Zhang; haibo, Chen; likuai, Shi; zhigang, Wu; gouhe, Yu; yanbin, Wang; sujun, Niu; Jin, Ye; Qi, Jin

To test the affect of environmental stresses on a adaptability of soil moisture capacitance sensor(FDR) a number of stresses were induced including vibrational shock as well as temperature and humidity through the use of a CH-I constant humidity chamber with variable temperature. A Vibrational platform was used to exam the resistance and structural integrity of the sensor after vibrations simulating the process of using, transporting and handling the sensor. A Impactive trial platform was used to test the resistance and structural integrity of the sensor after enduring repeated mechanical shocks. An CH-I constant humidity chamber with high-low temperature was used to test the adaptability of sensor in different environments with high temperature, low temperature and constant humidity. Otherwise, scope of magnetic force line of sensor was also tested in this paper. Test show:the capacitance type soil moisture sensor spread a feeling machine to bear heat, high wet and low temperature, at bear impact and vibration experiment in pass an examination, is a kind of environment to adapt to ability very strong instrument;Spread a feeling machine moreover electric field strength function radius scope 7 cms.

Potential Biotechnological Strategies for the Cleanup of Heavy Metals and Metalloids

PubMed Central

Mosa, Kareem A.; Saadoun, Ismail; Kumar, Kundan; Helmy, Mohamed; Dhankher, Om Parkash

2016-01-01

Global mechanization, urbanization, and various natural processes have led to the increased release of toxic compounds into the biosphere. These hazardous toxic pollutants include a variety of organic and inorganic compounds, which pose a serious threat to the ecosystem. The contamination of soil and water are the major environmental concerns in the present scenario. This leads to a greater need for remediation of contaminated soils and water with suitable approaches and mechanisms. The conventional remediation of contaminated sites commonly involves the physical removal of contaminants, and their disposition. Physical remediation strategies are expensive, non-specific and often make the soil unsuitable for agriculture and other uses by disturbing the microenvironment. Owing to these concerns, there has been increased interest in eco-friendly and sustainable approaches such as bioremediation, phytoremediation and rhizoremediation for the cleanup of contaminated sites. This review lays particular emphasis on biotechnological approaches and strategies for heavy metal and metalloid containment removal from the environment, highlighting the advances and implications of bioremediation and phytoremediation as well as their utilization in cleaning-up toxic pollutants from contaminated environments. PMID:27014323

Using NEON Data to Test and Refine Conceptual and Numerical Models of Soil Biogeochemical and Microbial Dynamics

NASA Astrophysics Data System (ADS)

Weintraub, S. R.; Stanish, L.; Ayers, E.

2017-12-01

Recent conceptual and numerical models have proposed new mechanisms that underpin key biogeochemical phenomena, including soil organic matter storage and ecosystem response to nitrogen deposition. These models seek to explicitly capture the ecological links among biota, especially microbes, and their physical and chemical environment to represent belowground pools and fluxes and how they respond to perturbation. While these models put forth exciting new concepts, their broad predictive abilities are unclear as some have been developed and tested against only small or regional datasets. The National Ecological Observatory Network (NEON) presents new opportunities to test and validate these models with multi-site data that span wide climatic, edaphic, and ecological gradients. NEON is measuring surface soil biogeochemical pools and fluxes along with diversity, abundance, and functional potential of soil microbiota at 47 sites distributed across the United States. This includes co-located measurements of soil carbon and nitrogen concentrations and stable isotopes, net nitrogen mineralization and nitrification rates, soil moisture, pH, microbial biomass, and community composition via 16S and ITS rRNA sequencing and shotgun metagenomic analyses. Early NEON data demonstrates that these wide edaphic and climatic gradients are related to changes in microbial community structure and functional potential, as well as element pools and process rates. Going forward, NEON's suite of standardized soil data has the potential to advance our understanding of soil communities and processes by allowing us to test the predictions of new soil biogeochemical frameworks and models. Here, we highlight several recently developed models that are ripe for this kind of data validation, and discuss key insights that may result. Further, we explore synergies with other networks, such as (i)LTER and (i)CZO, which may increase our ability to advance the frontiers of soil biogeochemical modeling.

Hyperspectral Imaging Analysis for the Classification of Soil Types and the Determination of Soil Total Nitrogen

PubMed Central

Jia, Shengyao; Li, Hongyang; Wang, Yanjie; Tong, Renyuan; Li, Qing

2017-01-01

Soil is an important environment for crop growth. Quick and accurately access to soil nutrient content information is a prerequisite for scientific fertilization. In this work, hyperspectral imaging (HSI) technology was applied for the classification of soil types and the measurement of soil total nitrogen (TN) content. A total of 183 soil samples collected from Shangyu City (People’s Republic of China), were scanned by a near-infrared hyperspectral imaging system with a wavelength range of 874–1734 nm. The soil samples belonged to three major soil types typical of this area, including paddy soil, red soil and seashore saline soil. The successive projections algorithm (SPA) method was utilized to select effective wavelengths from the full spectrum. Pattern texture features (energy, contrast, homogeneity and entropy) were extracted from the gray-scale images at the effective wavelengths. The support vector machines (SVM) and partial least squares regression (PLSR) methods were used to establish classification and prediction models, respectively. The results showed that by using the combined data sets of effective wavelengths and texture features for modelling an optimal correct classification rate of 91.8%. could be achieved. The soil samples were first classified, then the local models were established for soil TN according to soil types, which achieved better prediction results than the general models. The overall results indicated that hyperspectral imaging technology could be used for soil type classification and soil TN determination, and data fusion combining spectral and image texture information showed advantages for the classification of soil types. PMID:28974005

Bacterial Communities in Boreal Forest Mushrooms Are Shaped Both by Soil Parameters and Host Identity

PubMed Central

Pent, Mari; Põldmaa, Kadri; Bahram, Mohammad

2017-01-01

Despite recent advances in understanding the microbiome of eukaryotes, little is known about microbial communities in fungi. Here we investigate the structure of bacterial communities in mushrooms, including common edible ones, with respect to biotic and abiotic factors in the boreal forest. Using a combination of culture-based and Illumina high-throughput sequencing, we characterized the bacterial communities in fruitbodies of fungi from eight genera spanning four orders of the class Agaricomycetes (Basidiomycota). Our results revealed that soil pH followed by fungal identity are the main determinants of the structure of bacterial communities in mushrooms. While almost half of fruitbody bacteria were also detected from soil, the abundance of several bacterial taxa differed considerably between the two environments. The effect of host identity was significant at the fungal genus and order level and could to some extent be ascribed to the distinct bacterial community of the chanterelle, representing Cantharellales—the earliest diverged group of mushroom-forming basidiomycetes. These data suggest that besides the substantial contribution of soil as a major taxa source of bacterial communities in mushrooms, the structure of these communities is also affected by the identity of the host. Thus, bacteria inhabiting fungal fruitbodies may be non-randomly selected from environment based on their symbiotic functions and/or habitat requirements. PMID:28539921

Mycorrhizal colonization does not affect tolerance to defoliation of an annual herb in different light availability and soil fertility treatments but increases flower size in light-rich environments.

PubMed

Aguilar-Chama, Ana; Guevara, Roger

2012-01-01

Heterogeneous distribution of resources in most plant populations results in a mosaic of plant physiological responses tending to maximize plant fitness. This includes plant responses to trophic interactions such as herbivory and mycorrhizal symbiosis which are concurrent in most plants. We explored fitness costs of 50% manual defoliation and mycorrhizal inoculation in Datura stramonium at different light availability and soil fertility environments in a greenhouse experiment. Overall, we showed that non-inoculated and mycorrhiza-inoculated plants did not suffer from 50% manual defoliation in all the tested combinations of light availability and soil fertility treatments, while soil nutrients and light availability predominately affected plant responses to the mycorrhizal inoculation. Fifty percent defoliation had a direct negative effect on reproductive traits whereas mycorrhiza-inoculated plants produced larger flowers than non-inoculated plants when light was not a limiting factor. Although D. stramonium is a facultative selfing species, other investigations had shown clear advantages of cross-pollination in this species; therefore, the effects of mycorrhizal inoculation on flower size observed in this study open new lines of inquiry for our understanding of plant responses to trophic interactions. Also in this study, we detected shifts in the limiting resources affecting plant responses to trophic interactions.

Modeling coupled sorption and transformation of 17β-estradiol-17-sulfate in soil-water systems

NASA Astrophysics Data System (ADS)

Bai, Xuelian; Shrestha, Suman L.; Casey, Francis X. M.; Hakk, Heldur; Fan, Zhaosheng

2014-11-01

Animal manure is the primary source of exogenous free estrogens in the environment, which are known endocrine-disrupting chemicals to disorder the reproduction system of organisms. Conjugated estrogens can act as precursors to free estrogens, which may increase the total estrogenicity in the environment. In this study, a comprehensive model was used to simultaneously simulate the coupled sorption and transformation of a sulfate estrogen conjugate, 17β-estradiol-17-sulfate (E2-17S), in various soil-water systems (non-sterile/sterile; topsoil/subsoil). The simulated processes included multiple transformation pathways (i.e. hydroxylation, hydrolysis, and oxidation) and mass transfer between the aqueous, reversibly sorbed, and irreversibly sorbed phases of all soils for E2-17S and its metabolites. The conceptual model was conceived based on a series of linear sorption and first-order transformation expressions. The model was inversely solved using finite difference to estimate process parameters. A global optimization method was applied for the inverse analysis along with variable model restrictions to estimate 36 parameters. The model provided a satisfactory simultaneous fit (R2adj = 0.93 and d = 0.87) of all the experimental data and reliable parameter estimates. This modeling study improved the understanding on fate and transport of estrogen conjugates under various soil-water conditions.

Mobility and bio-availability of heavy metals in anthropogenically contaminated alluvial (deluvial) meadow soils (EUTRIC FLUVISOLS)

NASA Astrophysics Data System (ADS)

Dinev, Nikolai; Hristova, Mariana; Tzolova, Venera

2015-04-01

The total content of heavy metals is not sufficient to assess the pollution and the risk for environment as it does not provide information for the type and solubility of heavy metals' compounds in soils. The purpose was to study and determine the mobility of heavy metals in anthropogenically contaminated alluvial (delluvial) meadow soils spread around the non-ferrous plant near the town of Asenovgrad in view of risk assessment for environment pollution. Soil samples from monitoring network (1x1 km) was used. The sequential extraction procedure described by Zein and Brummer (1989) was applied. Results showed that the easily mobilizable cadmium compounds predominate in both contaminated and not contaminated soils. The stable form of copper (associated with silicate minerals, carbonates or amorphous and crystalline oxide compounds) predominates only in non polluted soils and reviles the risk of the environment contamination. Lead spreads and accumulates as highly soluble (mobile) compounds and between 72.3 and 99.6 percent of the total lead is bioavailable in soils. The procedure is very suitable for studying the mobility of technogenic lead and copper in alluvial soils with neutral medium reaction and in particular at the high levels of cadmium contamination. In soils with alkaline reaction - polluted and unpolluted the error of analysis increases for all studied elements.

Trace Metals and Nutrients at the Soil-Root Interface of Forest Soils

NASA Astrophysics Data System (ADS)

Courchesne, F.; Seguin, V.; Legrand, P.; Cloutier-Hurteau, B.

2004-05-01

The activity of roots creates a microenvironment, known as the rhizosphere, where soil properties, processes and feedback mechanisms differ substantially from those observed in the soil matrix. Due to its proximity to the site of elemental uptake by plants, the rhizosphere is viewed as a biogeochemical hotspot characterized by massive fluxes of matter and energy. In this context, the acquisition of new knowledge on the rhizosphere is crucial to increase our capacity to understand, manage and model soil-plants systems. Of particular interest to scientists is the response of the rhizosphere to perturbations of natural (e.g. climatic fluctuations) or anthropogenic (e.g. soil contamination) origin. Moreover, results from rhizosphere research help define new approaches designed either to restrict the entrance of potentially toxic elements in crops and, hence, in the food chain or, contrarily, to increase the uptake of trace elements by plants in contaminated environments to be bioremediated. Our recent studies in forested environments have clearly established that the rhizosphere (Abies, Acer, Betula, Picea, Pinus or Populus roots) is more acidic than the soil matrix and that it is enriched in organic substances (dissolved and solid), nutrient cations (Ca, Mg) and trace metals. Indeed, the rhizosphere systematically acts as a sink for Cd, Cu, Ni, Pb and Zn, notably under bioavailable (water-soluble and salt-extractable) forms. Yet, the relative activity of free metal ions is lower in the rhizosphere, as shown for Cu++, probably as a consequence of the higher DOC content. The corrosive environment forming in the rhizosphere, as controlled by the release of H+ ions and of organic acids, also impacts on mineral assemblages through an increase in the weathering of primary minerals (amphiboles, plagioclases) and the formation of secondary solid phases such as Fe and Al oxides. Some of the research avenues currently investigated by our research group include the quantification of functional links between organic carbon, microbial activity and metal speciation, the development of methodological and analytical approaches operating at the spatial scale of the rhizosphere and, the assessment of preferential hydrological fluxes along root networks.

New best estimates for radionuclide solid-liquid distribution coefficients in soils. Part 2: naturally occurring radionuclides.

PubMed

Vandenhove, H; Gil-García, C; Rigol, A; Vidal, M

2009-09-01

Predicting the transfer of radionuclides in the environment for normal release, accidental, disposal or remediation scenarios in order to assess exposure requires the availability of an important number of generic parameter values. One of the key parameters in environmental assessment is the solid liquid distribution coefficient, K(d), which is used to predict radionuclide-soil interaction and subsequent radionuclide transport in the soil column. This article presents a review of K(d) values for uranium, radium, lead, polonium and thorium based on an extensive literature survey, including recent publications. The K(d) estimates were presented per soil groups defined by their texture and organic matter content (Sand, Loam, Clay and Organic), although the texture class seemed not to significantly affect K(d). Where relevant, other K(d) classification systems are proposed and correlations with soil parameters are highlighted. The K(d) values obtained in this compilation are compared with earlier review data.

Virtual geotechnical laboratory experiments using a simulator

NASA Astrophysics Data System (ADS)

Penumadu, Dayakar; Zhao, Rongda; Frost, David

2000-04-01

The details of a test simulator that provides a realistic environment for performing virtual laboratory experimentals in soil mechanics is presented. A computer program Geo-Sim that can be used to perform virtual experiments, and allow for real-time observations of material response is presented. The results of experiments, for a given set of input parameters, are obtained with the test simulator using well-trained artificial neural-network-based soil models for different soil types and stress paths. Multimedia capabilities are integrated in Geo-Sim, using software that links and controls a laser disc player with a real-time parallel processing ability. During the simulation of a virtual experiment, relevant portions of the video image of a previously recorded test on an actual soil specimen are dispalyed along with the graphical presentation of response from the feedforward ANN model predictions. The pilot simulator developed to date includes all aspects related to performing a triaxial test on cohesionless soil under undrained and drained conditions. The benefits of the test simulator are also presented.

Long-Term Soil Experiments: A Key to Managing Earth's Rapidly Changing Critical Zones

NASA Astrophysics Data System (ADS)

Richter, D., Jr.

2014-12-01

In a few decades, managers of Earth's Critical Zones (biota, humans, land, and water) will be challenged to double food and fiber production and diminish adverse effects of management on the wider environment. To meet these challenges, an array of scientific approaches is being used to increase understanding of Critical Zone functioning and evolution, and one amongst these approaches needs to be long-term soil field studies to move us beyond black boxing the belowground Critical Zone, i.e., to further understanding of processes driving changes in the soil environment. Long-term soil experiments (LTSEs) provide direct observations of soil change and functioning across time scales of decades, data critical for biological, biogeochemical, and environmental assessments of sustainability; for predictions of soil fertility, productivity, and soil-environment interactions; and for developing models at a wide range of temporal and spatial scales. Unfortunately, LTSEs globally are not in a good state, and they take years to mature, are vulnerable to loss, and even today remain to be fully inventoried. Of the 250 LTSEs in a web-based network, results demonstrate that soils and belowground Critical Zones are highly dynamic and responsive to human management. The objective of this study is to review the contemporary state of LTSEs and consider how they contribute to three open questions: (1) can soils sustain a doubling of food production in the coming decades without further impinging on the wider environment, (2) how do soils interact with the global C cycle, and (3) how can soil management establish greater control over nutrient cycling. While LTSEs produce significant data and perspectives for all three questions, there is on-going need and opportunity for reviews of the long-term soil-research base, for establishment of an efficiently run network of LTSEs aimed at sustainability and improving management control over C and nutrient cycling, and for research teams that provide for generation to generation transfer of new and historic LTSEs.

EuroSoil2012: Soil science for the benefit of mankind and environment

USDA-ARS?s Scientific Manuscript database

EuroSoil2012 was convened in Bari ITALY from 2-6 July 2012 as the 4th International Congress of the European Confederation of Soil Science Societies (ECSSS). The theme of EuroSoil2012 as “soil science for the benefit of mankind and environment” aimed to cover several broad aspects of soil science w...

Modeling photodegradation kinetics of three systemic neonicotinoids-dinotefuran, imidacloprid, and thiamethoxam-in aqueous and soil environment.

PubMed

Kurwadkar, Sudarshan; Evans, Amanda; DeWinne, Dustan; White, Peter; Mitchell, Forrest

2016-07-01

Environmental presence and retention of commonly used neonicotinoid insecticides such as dinotefuran (DNT), imidacloprid (IMD), and thiamethoxam (THM) are a cause for concern and prevention because of their potential toxicity to nontarget species. In the present study the kinetics of the photodegradation of these insecticides were investigated in water and soil compartments under natural light conditions. The results suggest that these insecticides are fairly unstable in both aqueous and soil environments when exposed to natural sunlight. All 3 insecticides exhibit strong first-order degradation rate kinetics in the aqueous phase, with rate constants kDNT , kIMD , and kTHM of 0.20 h(-1) , 0.30 h(-1) , and 0.18 h(-1) , respectively. However, in the soil phase, the modeled photodegradation kinetics appear to be biphasic, with optimal rate constants k1DNT and k2DNT of 0.0198 h(-1) and 0.0022 h(-1) and k1THM and k2THM of 0.0053 h(-1) and 0.0014 h(-1) , respectively. Differentially, in the soil phase, imidacloprid appears to follow the first-order rate kinetics with a kIMD of 0.0013 h(-1) . These results indicate that all 3 neonicotinoids are photodegradable, with higher degradation rates in aqueous environments relative to soil environments. In addition, soil-encapsulated imidacloprid appears to degrade slowly compared with dinotefuran and thiamethoxam and does not emulate the faster degradation rates observed in the aqueous phase. Environ Toxicol Chem 2016;35:1718-1726. © 2015 SETAC. © 2015 SETAC.

Invasive Plants Rapidly Reshape Soil Properties in a Grassland Ecosystem.

PubMed

Gibbons, Sean M; Lekberg, Ylva; Mummey, Daniel L; Sangwan, Naseer; Ramsey, Philip W; Gilbert, Jack A

2017-01-01

Plant invasions often reduce native plant diversity and increase net primary productivity. Invaded soils appear to differ from surrounding soils in ways that impede restoration of diverse native plant communities. We hypothesize that invader-mediated shifts in edaphic properties reproducibly alter soil microbial community structure and function. Here, we take a holistic approach, characterizing plant, prokaryotic, and fungal communities and soil physicochemical properties in field sites, invasion gradients, and experimental plots for three invasive plant species that cooccur in the Rocky Mountain West. Each invader had a unique impact on soil physicochemical properties. We found that invasions drove shifts in the abundances of specific microbial taxa, while overall belowground community structure and functional potential were fairly constant. Forb invaders were generally enriched in copiotrophic bacteria with higher 16S rRNA gene copy numbers and showed greater microbial carbohydrate and nitrogen metabolic potential. Older invasions had stronger effects on abiotic soil properties, indicative of multiyear successions. Overall, we show that plant invasions are idiosyncratic in their impact on soils and are directly responsible for driving reproducible shifts in the soil environment over multiyear time scales. IMPORTANCE In this study, we show how invasive plant species drive rapid shifts in the soil environment from surrounding native communities. Each of the three plant invaders had different but consistent effects on soils. Thus, there does not appear to be a one-size-fits-all strategy for how plant invaders alter grassland soil environments. This work represents a crucial step toward understanding how invaders might be able to prevent or impair native reestablishment by changing soil biotic and abiotic properties.

Observations of magnetite dissolution in poorly drained soils

USGS Publications Warehouse

Grimley, D.A.; Arruda, N.K.

2007-01-01

Dissolution of strongly magnetic minerals is a common and relatively rapid phenomenon in poorly drained soils of the central United States, resulting in low magnetic susceptibility (MS). Low Eh reducing conditions are primarily responsible for magnetic mineral dissolution; a process likely mediated by iron-reducing bacteria in the presence of soil organic matter. Based on transects across drainage sequences from nine sites, natural magnetic minerals (>5 ??m) extracted from surface soil consist of 54% ?? 18% magnetite, 21% ?? 11% titanomagnetite, and 17% ?? 14% ilmenite. Magnetite and titanomagnetite dissolution, assessed by scanning electron microscopy on a 0-to-3 scale, inversely correlates with surface soil MS (r = 0.53), a proxy for soil drainage at studied transects. Altered magnetite typically displays etch pits 5 ??m) include 26% ?? 18% anthropogenic fly ash that also exhibits greater dissolution in low MS soils (r = 0.38), indicating detectable alteration can occur within 150 years in low Eh soils. Laboratory induced reduction of magnetite, titanomagnetite, and magnetic fly ash, with a citrate-bicarbonate- dithionite solution, resulted in dissolution textures similar to those of in situ soil particles. Although experiments indicate that reductive dissolution of magnetite can occur abiotically under extreme conditions, bacteria likely play an important role in the natural environment. ?? 2007 Lippincott Williams & Wilkins, Inc.

Fate of Prions in Soil: A Review

PubMed Central

Smith, Christen B.; Booth, Clarissa J.; Pedersen, Joel A.

2011-01-01

Prions are the etiological agents of transmissible spongiform encephalopathies (TSEs), a class of fatal neurodegenerative diseases affecting humans and other mammals. The pathogenic prion protein is a misfolded form of the host-encoded prion protein and represents the predominant, if not sole, component of the infectious agent. Environmental routes of TSE transmission are implicated in epizootics of sheep scrapie and chronic wasting disease (CWD) of deer, elk, and moose. Soil represents a plausible environmental reservoir of scrapie and CWD agents, which can persist in the environment for years. Attachment to soil particles likely influences the persistence and infectivity of prions in the environment. Effective methods to inactivate TSE agents in soil are currently lacking, and the effects of natural degradation mechanisms on TSE infectivity are largely unknown. An improved understanding of the processes affecting the mobility, persistence, and bioavailability of prions in soil is needed for the management of TSE-contaminated environments. PMID:21520752

Changes in gene expression during adaptation of Listeria monocytogenes to the soil environment.

PubMed

Piveteau, Pascal; Depret, Géraldine; Pivato, Barbara; Garmyn, Dominique; Hartmann, Alain

2011-01-01

Listeria monocytogenes is a ubiquitous opportunistic pathogen responsible for listeriosis. In order to study the processes underlying its ability to adapt to the soil environment, whole-genome arrays were used to analyse transcriptome modifications 15 minutes, 30 minutes and 18 h after inoculation of L. monocytogenes EGD-e in soil extracts. Growth was observed within the first day of incubation and large numbers were still detected in soil extract and soil microcosms one year after the start of the experiment. Major transcriptional reprofiling was observed. Nutrient acquisition mechanisms (phosphoenolpyruvate-dependent phosphotransferase systems and ABC transporters) and enzymes involved in catabolism of specific carbohydrates (β-glucosidases; chitinases) were prevalent. This is consistent with the overrepresentation of the CodY regulon that suggests that in a nutrient depleted environment, L. monocytogenes recruits its extensive repertoire of transporters to acquire a range of substrates for energy production.

The regulation by phenolic compounds of soil organic matter dynamics under a changing environment.

PubMed

Min, Kyungjin; Freeman, Chris; Kang, Hojeong; Choi, Sung-Uk

2015-01-01

Phenolics are the most abundant plant metabolites and are believed to decompose slowly in soils compared to other soil organic matter (SOM). Thus, they have often been considered as a slow carbon (C) pool in soil dynamics models. Here, however, we review changes in our concept about the turnover rate of phenolics and quantification of different types of phenolics in soils. Also, we synthesize current research on the degradation of phenolics and their regulatory effects on decomposition. Environmental changes, such as elevated CO2, warming, nitrogen (N) deposition, and drought, could influence the production and form of phenolics, leading to a change in SOM dynamics, and thus we also review the fate of phenolics under environmental disturbances. Finally, we propose the use of phenolics as a tool to control rates of SOM decomposition to stabilize organic carbon in ecosystems. Further studies to clarify the role of phenolics in SOM dynamics should include improving quantification methods, elucidating the relationship between phenolics and soil microorganisms, and determining the interactive effects of combinations of environmental changes on the phenolics production and degradation and subsequent impact on SOM processing.

Assessment of Mitigation Systems on Vapor Intrusion ...

EPA Pesticide Factsheets

Vapor intrusion is the migration of subsurface vapors, including radon and volatile organic compounds (VOCs), in soil gas from the subsurface to indoor air. Vapor intrusion happens because there are pressure and concentration differentials between indoor air and soil gas. Indoor environments are often negatively pressurized with respect to outdoor air and soil gas (for example, from exhaust fans or the stack effect), and this pressure difference allows soil gas containing subsurface vapors to flow into indoor air through advection. In addition, concentration differentials cause VOCs and radon to migrate from areas of higher to lower concentrations through diffusion, which is another cause of vapor intrusion. Current practice for evaluating the vapor intrusion pathway involves a multiple line of evidence approach based on direct measurements in groundwater, external soil gas, subslab soil gas, and/or indoor air. No single line of evidence is considered definitive, and direct measurements of vapor intrusion can be costly, especially where significant spatial and temporal variability require repeated measurements at multiple locations to accurately assess the chronic risks of long-term exposure to volatile organic compounds (VOCs) like chloroform, perchloroethylene (PCE), and trichloroethylene (TCE).

Microcolony Cultivation on a Soil Substrate Membrane System Selects for Previously Uncultured Soil Bacteria

PubMed Central

Ferrari, Belinda C.; Binnerup, Svend J.; Gillings, Michael

2005-01-01

Traditional microbiological methods of cultivation recover less than 1% of the total bacterial species, and the culturable portion of bacteria is not representative of the total phylogenetic diversity. Classical cultivation strategies are now known to supply excessive nutrients to a system and therefore select for fast-growing bacteria that are capable of colony or biofilm formation. New approaches to the cultivation of bacteria which rely on growth in dilute nutrient media or simulated environments are beginning to address this problem of selection. Here we describe a novel microcultivation method for soil bacteria that mimics natural conditions. Our soil slurry membrane system combines a polycarbonate membrane as a growth support and soil extract as the substrate. The result is abundant growth of uncharacterized bacteria as microcolonies. By combining microcultivation with fluorescent in situ hybridization, previously “unculturable” organisms belonging to cultivated and noncultivated divisions, including candidate division TM7, can be identified by fluorescence microscopy. Successful growth of soil bacteria as microcolonies confirmed that the missing culturable majority may have a growth strategy that is not observed when traditional cultivation indicators are used. PMID:16332866

Modeling Soil Moisture in Support of the Revegetation of Military Lands in Arid Regions.

NASA Astrophysics Data System (ADS)

Caldwell, T. G.; McDonald, E. V.; Young, M. H.

2003-12-01

The National Training Center (NTC), the Army's primary mechanized maneuver training facility, covers approximately 2600 km2 within the Mojave Desert in southern California, and is the subject of ongoing studies to support the sustainability of military lands in desert environments. Revegetation of these lands by the Integrated Training Areas Management (ITAM) Program requires the identification of optimum growing conditions to reestablish desert vegetation from seed and seedling, especially with regard to the timing and abundance of plant-available water. Water content, soil water potential, and soil temperature were continuously monitored and used to calibrate the Simultaneous Heat And Water (SHAW) model at 3 re-seeded sites. Modeled irrigation scenarios were used to further evaluate the most effective volume, frequency, and timing of irrigation required to maximize revegetation success and minimize water use. Surface treatments including straw mulch, gravel mulch, soil tackifier and plastic sheet

Estimates of critical acid loads and exceedances for forest soils across the conterminous United States.

PubMed

McNulty, Steven G; Cohen, Erika C; Moore Myers, Jennifer A; Sullivan, Timothy J; Li, Harbin

2007-10-01

Concern regarding the impacts of continued nitrogen and sulfur deposition on ecosystem health has prompted the development of critical acid load assessments for forest soils. A critical acid load is a quantitative estimate of exposure to one or more pollutants at or above which harmful acidification-related effects on sensitive elements of the environment occur. A pollutant load in excess of a critical acid load is termed exceedance. This study combined a simple mass balance equation with national-scale databases to estimate critical acid load and exceedance for forest soils at a 1-km(2) spatial resolution across the conterminous US. This study estimated that about 15% of US forest soils are in exceedance of their critical acid load by more than 250eqha(-1)yr(-1), including much of New England and West Virginia. Very few areas of exceedance were predicted in the western US.

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.

Soil Microbial Responses to Increased Moisture and Organic Resources along a Salinity Gradient in a Polar Desert

PubMed Central

Van Horn, David J.; Okie, Jordan G.; Buelow, Heather N.; Gooseff, Michael N.; Barrett, John E.

2014-01-01

Microbial communities in extreme environments often have low diversity and specialized physiologies suggesting a limited resistance to change. The McMurdo Dry Valleys (MDV) are a microbially dominated, extreme ecosystem currently undergoing climate change-induced disturbances, including the melting of massive buried ice, cutting through of permafrost by streams, and warming events. These processes are increasing moisture across the landscape, altering conditions for soil communities by mobilizing nutrients and salts and stimulating autotrophic carbon inputs to soils. The goal of this study was to determine the effects of resource addition (water/organic matter) on the composition and function of microbial communities in the MDV along a natural salinity gradient representing an additional gradient of stress in an already extreme environment. Soil respiration and the activity of carbon-acquiring extracellular enzymes increased significantly (P < 0.05) with the addition of resources at the low- and moderate-salinity sites but not the high-salinity site. The bacterial community composition was altered, with an increase in Proteobacteria and Firmicutes with water and organic matter additions at the low- and moderate-salinity sites and a near dominance of Firmicutes at the high-salinity site. Principal coordinate analyses of all samples using a phylogenetically informed distance matrix (UniFrac) demonstrated discrete clustering among sites (analysis of similarity [ANOSIM], P < 0.05 and R > 0.40) and among most treatments within sites. The results from this experimental work suggest that microbial communities in this environment will undergo rapid change in response to the altered resources resulting from climate change impacts occurring in this region. PMID:24610850

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.

Soil microbial responses to increased moisture and organic resources along a salinity gradient in a polar desert.

PubMed

Van Horn, David J; Okie, Jordan G; Buelow, Heather N; Gooseff, Michael N; Barrett, John E; Takacs-Vesbach, Cristina D

2014-05-01

Microbial communities in extreme environments often have low diversity and specialized physiologies suggesting a limited resistance to change. The McMurdo Dry Valleys (MDV) are a microbially dominated, extreme ecosystem currently undergoing climate change-induced disturbances, including the melting of massive buried ice, cutting through of permafrost by streams, and warming events. These processes are increasing moisture across the landscape, altering conditions for soil communities by mobilizing nutrients and salts and stimulating autotrophic carbon inputs to soils. The goal of this study was to determine the effects of resource addition (water/organic matter) on the composition and function of microbial communities in the MDV along a natural salinity gradient representing an additional gradient of stress in an already extreme environment. Soil respiration and the activity of carbon-acquiring extracellular enzymes increased significantly (P < 0.05) with the addition of resources at the low- and moderate-salinity sites but not the high-salinity site. The bacterial community composition was altered, with an increase in Proteobacteria and Firmicutes with water and organic matter additions at the low- and moderate-salinity sites and a near dominance of Firmicutes at the high-salinity site. Principal coordinate analyses of all samples using a phylogenetically informed distance matrix (UniFrac) demonstrated discrete clustering among sites (analysis of similarity [ANOSIM], P < 0.05 and R > 0.40) and among most treatments within sites. The results from this experimental work suggest that microbial communities in this environment will undergo rapid change in response to the altered resources resulting from climate change impacts occurring in this region.

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.

Review of “Managing Arsenic in the Environment: From Soil to Hman Health”

EPA Science Inventory

This is a book review of "Managing Arsenic in the Environment: From Soil to Human Health," R. Naidu, E. Smith, G. Owens, P. Bhattacharya, and P. Nadebaum eds., CSIRO Publishing, Melbourne, Australia, 656 pp.,

Improved Understanding of Fenton-like Reactions for the In Situ Remediation of Contaminated Groundwater Including Treatment of Sorbed Contaminants and Destruction of DNAPLs

DTIC Science & Technology

2006-04-29

Dehalogenation of Chlorinated Methanes by Iron Metal.” Environ . Sci. Technol. 28, 2045-2053. McBride, M.B. Environmental Chemistry of Soils; Oxford Press: New...Oxidative Transformation of Triclosan and Chlorophene by Manganese Oxides. Environ . Sci. Technol. 2003, 37, 2421-2430 Zhang, Y., Crittenden, J.C...prepared under contract to the Department of Defense Strategic Environmental Research and Development Program (SERDP). The publication of this report does

Soil phosphorus - new insights into a critical cycle across many soil functions

NASA Astrophysics Data System (ADS)

Leinweber, Peter; Zimmer, Dana

2017-04-01

The fate of phosphorus (P-) compounds in the soil - plant - water - system is linked with most soil functions such as productivity for agricultural crops, reactor for nutrient cycling, filter and buffer for water, and biodiversity. The P-compounds, mostly phosphates in a multitude of chemical bonds, may have contradicting influences on soil functions. For instance, P-concentrations may be suboptimal for crop yields but at the same time exceeding the soil filter/buffer capacity for water resources. Modern agriculture has increased this misbalance. Therefore, a better soil P management that balances all soil functions requires a deeper understanding of the P-cycling in the environment. The collaborative project "InnoSoilPhos" in the frame of the BonaRes-program of the German Federal Ministry of Education and Research (BMBF) aims at disclosing the chemical composition, biogeochemical transformations and microbiological fundamentals of P-cycling and P-transport processes across all relevant scales from atomic to catchment and landscapes. The contribution will give an overview on the project and some examples for the latest findings on P-reactions at mineral surfaces (experimental and theoretical), microorganism diversity involved in soil P-transformations, crop yield responses to P-fertilizer regimes (including new P-recycling products) and, finally, hot spots and hot moments of P-release from soils into adjoining freshwater systems. These findings allow some preliminary demands and frame conditions for an improved soil P management to better balance the soil functions and safe the global mineable P resources.

Leaching behavior of veterinary antibiotics in animal manure-applied soils.

PubMed

Pan, Min; Chu, L M

2017-02-01

Agricultural fields worldwide are being contaminated by the escalating application of veterinary antibiotics (VAs) via animal manure and biosolids applied as fertilizers or of wastewater for irrigation, resulting in soil degradation and damage to the health of terrestrial environments. This paper describes a series of column studies investigating the leaching behavior of five VAs, tetracycline (TC), sulfamethazine (SMZ), norfloxacin (NOR), erythromycin (ERY) and chloramphenicol (CAP), under different simulated rainfall conditions that could occur in agricultural environments. Our aim was to explore the effects of acid rain and torrential rain on the leaching of different VAs and to determine their leaching behaviors along the soil profile. The results showed that acid rain accelerated the accumulation of VAs from animal manure in surface soil while long rainfall durations promoted the downward migration of VAs in soil. Under acid rain conditions, a higher concentration of VAs remained in the animal manure. More VAs were eluted to deeper soil layers and the leachate under extreme rainfall conditions. The leachability of VAs was higher in sandy soil than in clay or loamy soil. SMZ and ERY posed a higher risk to deeper soil layers and groundwater, while NOR and TC tended to persist in surface soil, which can be explained by their different physicochemical properties in soil. Moreover, the general trends from two model assessments and soil column measurements appeared to be in agreement. SMZ had a high leachability, while NOR tended to accumulate in soils. This study provided vital insight into the persistence mechanisms of VAs in terrestrial environments and their potential risks to soils and groundwater. Copyright © 2016 Elsevier B.V. All rights reserved.

How do soil physical conditions for crop growth vary over time under established contrasting tillage regimes?

NASA Astrophysics Data System (ADS)

Hallett, Paul; Stobart, Ron; Valentine, Tracy; George, Timothy; Morris, Nathan; Newton, Adrian; McKenzie, Blair

2014-05-01

When plant breeders develop modern cereal varieties for the sustainable intensification of agriculture, insufficient thought is given to the impact of tillage on soil physical conditions for crop production. In earlier work, we demonstrated that barley varieties that perform best in ploughed soil (the approach traditionally used for breeding trials) were not the same as those performing best under shallow non-inversion or zero-tillage. We also found that the Quantitative Trait Loci (QTL) associated with improved phosphorus uptake, and hence useful for marker assisted breeding, were not robust between different tillage regimes. The impact of the soil environment had greater impact than the genetics in GxE interactions. It is obvious that soil tillage should be considered when breeding the next generation of crops. Tillage may also have important impacts on carbon storage, but we found that despite greater soil carbon at shallow depths under non-inversion tillage, the carbon stored throughout the soil profile was not affected by tillage. Studies on soil tillage impacts to crop productivity and soil quality are often performed in one season, on single sites that have had insufficient time to develop. Our current research explores multiple sites, on different soils, with temporal measurements of soil physical conditions under contrasting tillage regimes. We use the oldest established contemporary tillage experiments in the United Kingdom, with all sites sharing ploughed and shallow (7cm) non-inversion tillage treatments. In eastern Scotland (Mid Pilmore), the site also has zero tillage and deep ploughing (40 cm) treatments, and was established 11 years ago. In east England there are two sites, both also having a deep non-inversion tillage treatment, and they were established 6 (New Farm Systems) and 8 (STAR) years ago. We measure a range of crop and soil properties at sowing, one month after sowing and post-harvest, including rapid lab based assays that allow high-throughput. Samples are taken over the rooting zone in the topsoil, plough pan and subsoil. The first year's dataset from this comprehensive project will be presented. Early data identified plough pans under shallow non-inversion tillage that will limit root growth at all sites. Aggregate stabilities vary as expected, with plough soils at shallow depth being less stable than non-inversion tillage, but greater stability in plough soils at greater depth due to incorporated organic matter. Very rapidly following cultivation, the seedbeds coalesce, resulting in a more challenging physical environment for crop growth. We are exploring the mechanisms in soil structure temporal dynamics in greater detail, including the resilience of seedbeds to structural degradation through natural weathering and the action of plants. These profound differences in soil conditions will impact the root ideotype of crops for these different conditions. This has implications for the way in which breeding and genotype selection is performed in the future. Ultimately, we aim to identify crop varieties suited to local soil conditions and management, possibly with root traits that boost yields and soil physical quality.

Environmental impacts of coal mine and thermal power plant to the surroundings of Barapukuria, Dinajpur, Bangladesh.

PubMed

Hossain, Md Nazir; Paul, Shitangsu Kumar; Hasan, Md Muyeed

2015-04-01

The study was carried out to analyse the environmental impacts of coal mine and coal-based thermal power plant to the surrounding environment of Barapukuria, Dinajpur. The analyses of coal, water, soil and fly ash were carried out using standard sample testing methods. This study found that coal mining industry and coal-based thermal power plant have brought some environmental and socio-economic challenges to the adjacent areas such as soil, water and air pollution, subsidence of agricultural land and livelihood insecurity of inhabitants. The pH values, heavy metal, organic carbon and exchangeable cations of coal water treated in the farmland soil suggest that coal mining deteriorated the surrounding water and soil quality. The SO4(2-) concentration in water samples was beyond the range of World Health Organisation standard. Some physico-chemical properties such as pH, conductivity, moisture content, bulk density, unburned carbon content, specific gravity, water holding capacity, liquid and plastic limit were investigated on coal fly ash of Barapukuria thermal power plant. Air quality data provided by the Barapukuria Coal Mining Company Limited were contradictory with the result of interview with the miners and local inhabitants. However, coal potentially contributes to the development of economy of Bangladesh but coal mining deteriorates the environment by polluting air, water and soil. In general, this study includes comprehensive baseline data for decision makers to evaluate the feasibility of coal power industry at Barapukuria and the coalmine itself.

Organic-Carbon Sequestration in Soil/Sediment of the Mississippi River Deltaic Plain - Data; Landscape Distribution, Storage, and Inventory; Accumulation Rates; and Recent Loss, Including a Post-Katrina Preliminary Analysis (Chapter B)

USGS Publications Warehouse

Markewich, Helaine W.; Buell, Gary R.; Britsch, Louis D.; McGeehin, John P.; Robbins, John A.; Wrenn, John H.; Dillon, Douglas L.; Fries, Terry L.; Morehead, Nancy R.

2007-01-01

Soil/sediment of the Mississippi River deltaic plain (MRDP) in southeastern Louisiana is rich in organic carbon (OC). The MRDP contains about 2 percent of all OC in the surface meter of soil/sediment in the Mississippi River Basin (MRB). Environments within the MRDP differ in soil/sediment organic carbon (SOC) accumulation rate, storage, and inventory. The focus of this study was twofold: (1) develop a database for OC and bulk density for MRDP soil/sediment; and (2) estimate SOC storage, inventory, and accumulation rates for the dominant environments (brackish, intermediate, and fresh marsh; natural levee; distributary; backswamp; and swamp) in the MRDP. Comparative studies were conducted to determine which field and laboratory methods result in the most accurate and reproducible bulk-density values for each marsh environment. Sampling methods included push-core, vibracore, peat borer, and Hargis1 sampler. Bulk-density data for cores taken by the 'short push-core method' proved to be more internally consistent than data for samples collected by other methods. Laboratory methods to estimate OC concentration and inorganic-constituent concentration included mass spectrometry, coulometry, and loss-on-ignition. For the sampled MRDP environments, these methods were comparable. SOC storage was calculated for each core with adequate OC and bulk-density data. SOC inventory was calculated using core-specific data from this study and available published and unpublished pedon data linked to SSURGO2 map units. Sample age was estimated using isotopic cesium (137Cs), lead (210Pb), and carbon (14C), elemental Pb, palynomorphs, other stratigraphic markers, and written history. SOC accumulation rates were estimated for each core with adequate age data. Cesium-137 profiles for marsh soil/sediment are the least ambiguous. Levee and distributary 137Cs profiles show the effects of intermittent allochthonous input and/or sediment resuspension. Cesium-137 and 210Pb data gave the most consistent and interpretable information for age estimations of soil/sediment deposited during the 1900s. For several cores, isotopic 14C and 137Cs data allowed the 1963-64 nuclear weapons testing (NWT) peak-activity datum to be placed within a few-centimeter depth interval. In some cores, a too old 14C age (when compared to 137Cs and microstratigraphic-marker data) is the probable result of old carbon bound to clay minerals incorporated into the organic soil/sediment. Elemental Pb coupled with Pb source-function data allowed age estimation for soil/sediment that accumulated during the late 1920s through the 1980s. Exotic pollen (for example, Vigna unguiculata and Alternanthera philoxeroides) and other microstratigraphic indicators (for example, carbon spherules) allowed age estimations for marsh soil/sediment deposited during the settlement of New Orleans (1717-20) through the early 1900s. For this study, MRDP distributary and swamp environments were each represented by only one core, backswamp environment by two cores, all other environments by three or more cores. MRDP core data for the surface meter soil/sediment indicate that (1) coastal marshes, abandoned distributaries, and swamps have regional SOC-storage values >16 kg m-2; (2) swamps and abandoned distributaries have the highest SOC storage values (swamp, 44.8 kg m-2; abandoned distributary, 50.9 kg m-2); (3) fresh-to-brackish marsh environments have the second highest site-specific SOC-storage values; and (4) site-specific marsh SOC storage values decrease as the salinity of the environment increases (fresh-marsh, 36.2 kg m-2; intermediate marsh, 26.2 kg m-2; brackish marsh, 21.5 kg m-2). This inverse relation between salinity and SOC storage is opposite the regional systematic increase in SOC storage with increasing salinity that is evident when SOC storage is mapped by linking pedon data to SSURGO map units (fresh marsh, 47 kg m-2; intermediate marsh, 67 kg m-2; brackish marsh, 75 kg m-2; and salt marsh, 80 kg m-2). MRDP core data for this study also indicate that levees and backswamp have regional SOC-storage values <16 kg m-2. Group-mean SOC storage for cores from these environments are natural levee (17.0 kg m-2) and backswamp (14.1 kg m-2). An estimate for the SOC inventory in the surface meter of soil/sediment in the MRDP can be made using the SSURGO mapped portion of the coastal-marsh vegetative-type map (13,236 km2, land-only area) published by the Louisiana Department of Wildlife and Fisheries and U.S. Geological Survey (1997). This area has a SOC inventory (surface meter) of 677 Tg (slightly more than 2 percent of the 30,289 Tg SOC inventory for the MRB). The MRDP (6,180 km2, land-only area) has an estimated SOC inventory of 397 Tg. Most of the MRDP is located within the SSURGO mapped coastal marshlands. The entire MRDP, including water, has an area of about 10,800 km2. Using the ratio of total MRDP area to SSURGO mapped MRDP area as an adjustment, the MRDP SOC inventory is estimated at 694 Tg. This larger estimate of 694 Tg for the SOC inventory is probably more realistic, because it is reasonable to assume that the marsh sediments overlain by shallow water have comparable SOC storage to that of the adjacent land areas. MRDP core data for this study indicate that there is some variability in long-term SOC mass-accumulation rates for centuries and millennia and that this variability may indicate important geologic changes or changes in land use. However, the consistency of the range in rates of SOC accumulation through time suggests a remarkable degree of marsh sustainability throughout the Holocene, including the recent period of significant marsh modification/channelization for human use. One example of marsh sustainability is its present ability to function as a SOC sink even with Louisiana's large-scale coastal land loss during the last several decades. With coastal-marsh restoration efforts, this sink potential will increase. Looking to the future, a total of 1,101 g m-2 yr-1 SOC is projected to be lost from all of coastal Louisiana (U.S. Army Corps of Engineers, Louisiana Coastal Area (LCA) subprovinces 1-4; not just the MRDP) through coastal erosion from year 2000 to 2050. This translates to a projected SOC-loss rate of about 0.20 percent per year. The recent Hurricanes Katrina and Rita, which devastated the Louisiana coast during late August and late September 2005, transformed about 259 km2 (100 mi2) of marsh to open water (U.S. Geological Survey, 2005). To the extent that some or all of this land loss is permanent, this result equates to a SOC loss of about 15 Tg. This estimate is based on the year-2000 15,153-km2 land area for the LCA study area that includes LCA subprovince 4. Using the year-2000 land area, the LCA study area had an estimated SOC inventory of 858 Tg. The estimated 15 Tg SOC loss attributable to Hurricanes Katrina and Rita is 1.7 percent of the year-2000 LCA inventory and 2.3 percent of the year-2000 MRDP inventory. If this SOC loss is included in the projection for the year 2050, then the MRDP would either remain a source with a net SOC loss of 3 Tg or become a weak sink with a net SOC gain of 4 Tg. These estimates are lower bounds for potential SOC flux because they are only for the surface meter of landmass.

Multifunctional properties of phosphate-solubilizing microorganisms grown on agro-industrial wastes in fermentation and soil conditions.

PubMed

Vassileva, Maria; Serrano, Mercedes; Bravo, Vicente; Jurado, Encarnación; Nikolaeva, Iana; Martos, Vanessa; Vassilev, Nikolay

2010-02-01

One of the most studied approaches in solubilization of insoluble phosphates is the biological treatment of rock phosphates. In recent years, various techniques for rock phosphate solubilization have been proposed, with increasing emphasis on application of P-solubilizing microorganisms. The P-solubilizing activity is determined by the microbial biochemical ability to produce and release metabolites with metal-chelating functions. In a number of studies, we have shown that agro-industrial wastes can be efficiently used as substrates in solubilization of phosphate rocks. These processes were carried out employing various technologies including solid-state and submerged fermentations including immobilized cells. The review paper deals critically with several novel trends in exploring various properties of the above microbial/agro-wastes/rock phosphate systems. The major idea is to describe how a single P-solubilizing microorganism manifests wide range of metabolic abilities in different environments. In fermentation conditions, P-solubilizing microorganisms were found to produce various enzymes, siderophores, and plant hormones. Further introduction of the resulting biotechnological products into soil-plant systems resulted in significantly higher plant growth, enhanced soil properties, and biological (including biocontrol) activity. Application of these bio-products in bioremediation of disturbed (heavy metal contaminated and desertified) soils is based on another important part of their multifunctional properties.

Impact of biostimulated redox processes on metal dynamics in an iron-rich creek soil of a former uranium mining area.

PubMed

Burkhardt, Eva-Maria; Akob, Denise M; Bischoff, Sebastian; Sitte, Jana; Kostka, Joel E; Banerjee, Dipanjan; Scheinost, Andreas C; Küsel, Kirsten

2010-01-01

Understanding the dynamics of metals and radionuclides in soil environments is necessary for evaluating risks to pristine sites. An iron-rich creek soil of a former uranium-mining district (Ronneburg, Germany) showed high porewater concentrations of heavy metals and radionuclides. Thus, this study aims to (i) evaluate metal dynamics during terminal electron accepting processes (TEAPs) and (ii) characterize active microbial populations in biostimulated soil microcosms using a stable isotope probing (SIP) approach. In biostimulated soil slurries, concentrations of soluble Co, Ni, Zn, As, and unexpectedly U increased during Fe(III)-reduction. This suggests that there was a release of sorbed metals and As during reductive dissolution of Fe(III)-oxides. Subsequent sulfate-reduction was concurrent with a decrease of U, Co, Ni, and Zn concentrations. The relative contribution of U(IV) in the solid phase changed from 18.5 to 88.7% after incubation. The active Fe(III)-reducing population was dominated by delta-Proteobacteria (Geobacter) in (13)C-ethanol amended microcosms. A more diverse community was present in (13)C-lactate amended microcosms including taxa related to Acidobacteria, Firmicutes, delta-Proteobacteria, and beta-Proteobacteria. Our results suggested that biostimulated Fe(III)-reducing communities facilitated the release of metals including U to groundwater which is in contrast to other studies.

[Effects of biochar on microbial ecology in agriculture soil: a review].

PubMed

Ding, Yan-Li; Liu, Jie; Wang, Ying-Ying

2013-11-01

Biochar, as a new type of soil amendment, has been obtained considerable attention in the research field of environmental sciences worldwide. The studies on the effects of biochar in improving soil physical and chemical properties started quite earlier, and already covered the field of soil microbial ecology. However, most of the studies considered the soil physical and chemical properties and the microbial ecology separately, with less consideration of their interactions. This paper summarized and analyzed the interrelationships between the changes of soil physical and chemical properties and of soil microbial community after the addition of biochar. Biochar can not only improve soil pH value, strengthen soil water-holding capacity, increase soil organic matter content, but also affect soil microbial community structure, and alter the abundance of soil bacteria and fungi. After the addition of biochar, the soil environment and soil microorganisms are interacted each other, and promote the improvement of soil microbial ecological system together. This review was to provide a novel perspective for the in-depth studies of the effects of biochar on soil microbial ecology, and to promote the researches on the beneficial effects of biochar to the environment from ecological aspect. The methods to improve the effectiveness of biochar application were discussed, and the potential applications of biochar in soil bioremediation were further analyzed.

Demonstration of an In-Situ Friction-Sound Probe for Mapping Particle Size at Contaminated Sediment Sites

DTIC Science & Technology

2013-09-01

management practices resulting in the release of contaminants to soil , sediment, and groundwater in coastal environments. At contaminated sediment sites it...the release of contaminants to soil , sediment, and groundwater in coastal environments. Areas of potential concern at these sites are identified by...study will acquire additional soil and groundwater data necessary to satisfactorily evaluate remedial technologies and develop cleanup goals supporting

A plane-type soil sampler

USGS Publications Warehouse

Frey, Paul J.

1963-01-01

While studying the effects of pesticides on fish and their environment for the Bureau of Sport Fisheries and Wildlife, I have developed a soil sampler that will collect a thin uniform layer of sediment from pond and stream bottoms. As it is becoming increasingly important to analyze the residual deposits of pesticides in this shallow layer of soil in aquatic environments, it seems useful to describe the apparatus and compare it with other samplers.

A model-data fusion analysis for examining the response of carbon exchange to environmental variation in crop field

NASA Astrophysics Data System (ADS)

Yokozawa, M.; Sakurai, G.; Ono, K.; Mano, M.; Miyata, A.

2011-12-01

Agricultural activities, cultivating crops, managing soil, harvesting and post-harvest treatments, are not only affected from the surrounding environment but also change the environment reversely. The changes in environment, temperature, radiation and precipitation, brings changes in crop productivity. On the other hand, the status of crops, i.e. the growth and phenological stage, change the exchange of energy, H2O and CO2 between crop vegetation surface and atmosphere. Conducting the stable agricultural harvests, reducing the Greenhouse Effect Gas (GHG) emission and enhancing carbon sequestration in soil are preferable as a win-win activity. We conducted model-data fusion analysis for examining the response of cropland-atmosphere carbon exchange to environmental variation. The used model consists of two sub models, paddy rice growth sub-model and soil decomposition sub-model. The crop growth sub-model mimics the rice plant growth processes including formation of reproductive organs as well as leaf expansion. The soil decomposition sub-model simulates the decomposition process of soil organic carbon. Assimilating the data on the time changes in CO2 flux measured by eddy covariance method, rice plant biomass, LAI and the final yield with the model, the parameters were calibrated using a stochastic optimization algorithm with a particle filter. The particle filter, which is one of Monte Carlo filters, enable us to evaluating time changes in parameters based on the observed data until the time and to make prediction of the system. Iterative filtering and prediction with changing parameters and/or boundary condition enable us to obtain time changes in parameters governing the crop production as well as carbon exchange. In this paper, we applied the model-data fusion analysis to the two datasets on paddy rice field sites in Japan: only a single rice cultivation, and a single rice and wheat cultivation. We focused on the parameters related to crop production as well as soil carbon storage. As a result, the calibrated model with estimated parameters could accurately predict the NEE flux in the subsequent years (Fig.1). The temperature sensitivity, Q10s in the decomposition rate of soil organic carbon (SOC) were obtained as 1.4 for no cultivation period and 2.9 for cultivation period (submerged soil condition).

Microbial Community Dynamics in Soil Depth Profiles Over 120,000 Years of Ecosystem Development

PubMed Central

Turner, Stephanie; Mikutta, Robert; Meyer-Stüve, Sandra; Guggenberger, Georg; Schaarschmidt, Frank; Lazar, Cassandre S.; Dohrmann, Reiner; Schippers, Axel

2017-01-01

Along a long-term ecosystem development gradient, soil nutrient contents and mineralogical properties change, therefore probably altering soil microbial communities. However, knowledge about the dynamics of soil microbial communities during long-term ecosystem development including progressive and retrogressive stages is limited, especially in mineral soils. Therefore, microbial abundances (quantitative PCR) and community composition (pyrosequencing) as well as their controlling soil properties were investigated in soil depth profiles along the 120,000 years old Franz Josef chronosequence (New Zealand). Additionally, in a microcosm incubation experiment the effects of particular soil properties, i.e., soil age, soil organic matter fraction (mineral-associated vs. particulate), O2 status, and carbon and phosphorus additions, on microbial abundances (quantitative PCR) and community patterns (T-RFLP) were analyzed. The archaeal to bacterial abundance ratio not only increased with soil depth but also with soil age along the chronosequence, coinciding with mineralogical changes and increasing phosphorus limitation. Results of the incubation experiment indicated that archaeal abundances were less impacted by the tested soil parameters compared to Bacteria suggesting that Archaea may better cope with mineral-induced substrate restrictions in subsoils and older soils. Instead, archaeal communities showed a soil age-related compositional shift with the Bathyarchaeota, that were frequently detected in nutrient-poor, low-energy environments, being dominant at the oldest site. However, bacterial communities remained stable with ongoing soil development. In contrast to the abundances, the archaeal compositional shift was associated with the mineralogical gradient. Our study revealed, that archaeal and bacterial communities in whole soil profiles are differently affected by long-term soil development with archaeal communities probably being better adapted to subsoil conditions, especially in nutrient-depleted old soils. PMID:28579976

Selected micrometeorological and soil-moisture data at Amargosa Desert Research Site, an arid site near Beatty, Nye County, Nevada, 1998-2000

USGS Publications Warehouse

Johnson, Michael J.; Mayers, Charles J.; Andraski, Brian J.

2002-01-01

Selected micrometeorological and soil-moisture data were collected at the Amargosa Desert Research Site adjacent to a low-level radioactive waste and hazardous chemical waste facility near Beatty, Nev., 1998-2000. Data were collected in support of ongoing research studies to improve the understanding of hydrologic and contaminant-transport processes in arid environments. Micrometeorological data include precipitation, air temperature, solar radiation, net radiation, relative humidity, ambient vapor pressure, wind speed and direction, barometric pressure, soil temperature, and soil-heat flux. All micrometeorological data were collected using a 10-second sampling interval by data loggers that output daily mean, maximum, and minimum values, and hourly mean values. For precipitation, data output consisted of daily, hourly, and 5-minute totals. Soil-moisture data included periodic measurements of soil-water content at nine neutron-probe access tubes with measurable depths ranging from 5.25 to 29.75 meters. The computer data files included in this report contain the complete micrometeorological and soil-moisture data sets. The computer data consists of seven files with about 14 megabytes of information. The seven files are in tabular format: (1) one file lists daily mean, maximum, and minimum micrometeorological data and daily total precipitation; (2) three files list hourly mean micrometeorological data and hourly precipitation for each year (1998-2000); (3) one file lists 5-minute precipitation data; (4) one file lists mean soil-water content by date and depth at four experimental sites; and (5) one file lists soil-water content by date and depth for each neutron-probe access tube. This report highlights selected data contained in the computer data files using figures, tables, and brief discussions. Instrumentation used for data collection also is described. Water-content profiles are shown to demonstrate variability of water content with depth. Time-series data are plotted to illustrate temporal variations in micrometeorological and soil-water content data. Substantial precipitation at the end of an El Ni?o cycle in early 1998 resulted in measurable water penetration to a depth of 1.25 meters at one of the four experimental soil-monitoring sites.

Analysing the mechanisms of soil water and vapour transport in the desert vadose zone of the extremely arid region of northern China

NASA Astrophysics Data System (ADS)

Du, Chaoyang; Yu, Jingjie; Wang, Ping; Zhang, Yichi

2018-03-01

The transport of water and vapour in the desert vadose zone plays a critical role in the overall water and energy balances of near-surface environments in arid regions. However, field measurements in extremely dry environments face many difficulties and challenges, so few studies have examined water and vapour transport processes in the desert vadose zone. The main objective of this study is to analyse the mechanisms of soil water and vapour transport in the desert vadose zone (depth of ∼350 cm) by using measured and modelled data in an extremely arid environment. The field experiments are implemented in an area of the Gobi desert in northwestern China to measure the soil properties, daily soil moisture and temperature, daily water-table depth and temperature, and daily meteorological records from DOYs (Days of Year) 114-212 in 2014 (growing season). The Hydrus-1D model, which simulates the coupled transport of water, vapour and heat in the vadose zone, is employed to simulate the layered soil moisture and temperature regimes and analyse the transport processes of soil water and vapour. The measured results show that the soil water and temperatures near the land surface have visible daily fluctuations across the entire soil profile. Thermal vapour movement is the most important component of the total water flux and the soil temperature gradient is the major driving factor that affects vapour transport in the desert vadose zone. The most active water and heat exchange occurs in the upper soil layer (depths of 0-25 cm). The matric potential change from the precipitation mainly re-draws the spatio-temporal distribution of the isothermal liquid water in the soil near the land surface. The matric potential has little effect on the isothermal vapour and thermal liquid water flux. These findings offer new insights into the liquid water and vapour movement processes in the extremely arid environment.

Influence of soil sampling approaches in the evaluation of soil organic carbon stocks under different land uses in a Mediterranean area

NASA Astrophysics Data System (ADS)

Francaviglia, Rosa; Doro, Luca; Ledda, Luigi; Parras-Alcántara, Luis; Lozano-García, Beatriz

2016-04-01

Different approaches of soil sampling can provide significantly different estimates of soil organic carbon stocks (SOCs) (Parras-Alcántara et al., 2015a). Many studies have focused on SOC distribution only in the biologically active layers of topsoil, the IPCC carbon accounting method estimates the change in SOC storage for the top 30 cm of a soil profile, and indeed limited data are available for SOCs below this depth. Moreover, SOC estimates are more uncertain in areas with heterogeneous land uses and pedoclimatic conditions such as Mediterranean environments, which are more prone to land degradation due to SOC degradation and depletion and erosive processes (Muñoz-Rojas et al., 2015). Anyhow, the open question is whether soil should be sampled following the pedogenetic horizons with soil entire soil approach (ESP), or along fixed depth increments using the soil control section method (SCS) (Parras-Alcántara et al., 2015b). In addition, SOCs are often not adjusted for the soil volume occupied by coarse fragments as recommended by the IPCC Good Practice Guidance for LULUCF (IPCC, 2003) accordingly to the equation: SOCs = SOC (g kg-1) × bulk density (Mg m-3) × depth (m) × (1 - coarse fragment) × 10. The work deals with the comparison of SOCs using the ESP and SCS approaches, applied to a study area of northeastern Sardinia (Italy) under typical agro-silvo-pastoral systems (Francaviglia et al., 2014). The area lies within a hilly basin where elevation is in the range 275-340 m a.s.l., and slope ranges from 2-6% to 16-30%. The local climate is warm temperate with dry and hot summers, mean annual rainfall is 623 mm (range 367-811mm) and mean annual temperature is 15.0° C (13.8-16.4° C). The area has the same soil type (Haplic Endoleptic Cambisols, Dystric) according to IUSS Working Group WRB (2006), and the following land uses with different levels of cropping intensification were compared: Tilled vineyards (Tv), No-tilled grassed vineyards (Ntgv), Hay crop (Hc), Pasture (P), Cork oak forest (Cof), former vineyards revegetated by Scrublands (Sfv), Mediterranean Maquis (Mmfv), and Helichrysum meadows (Hmfv). Average total SOCs were 128.0 and 140.6 Mg ha-1with the ESP and SCS approaches respectively if the coarse fraction is not included in the equation, 79.0 and 90.4 Mg ha-1when the coarse fraction is included. This indicates the importance to consider the coarse fraction when estimating SOC stocks, and an overestimation of SOCs when SCS sampling approach is adopted equal to about 16%. References Francaviglia, R., Benedetti, A., Doro, L., Madrau, S., Ledda, S., 2014. Influence of land use on soil quality and stratification ratios under agro-silvo-pastoral Mediterranean management systems. Agriculture, Ecosystems and Environment 183, 86-92. Intergovernmental Panel on Climate Change (IPCC), 2003. In: Penman, J., Gytarsky, M., Hiraishi, T., Krug, T., Kruger, D., Pipatti, R., Buendia, L., Miwa, K., Ngara, T., Tanabe, K., Wagner, F. (Eds.), Good Practice Guidance for Land Use, Land Use Change and Forestry. IPCC/OECD/IEA/IGES, Hayama, Japan. IUSS Working Group WRB, 2006.World reference base for soil resources 2006.World Soil Resources Reports No. 103. FAO, Rome. Muñoz-Rojas, M., Doro, L., Ledda, L., Francaviglia, R., 2015. Application of CarboSOIL model to predict the effects of climate change on soil organic carbon stocks in agro-silvo-pastoral Mediterranean management systems. Agriculture, Ecosystems and Environment 202, 8-16. Parras-Alcántara, L., Lozano-García, B., Brevik, E. C., Cerdá, A., 2015a. Soil organic carbon stocks quanti?cation in Mediterranean natural areas, a trade-off between entire soil pro?les and soil control sections. EGU General Assembly. Geophysical Research Abstracts Vol. 17, 2015-9865. Parras-Alcántara, L., Lozano-García, B., Brevik, E., C., Cerdá, A., 2015b. Soil organic carbon stocks assessment in Mediterranean natural areas: A comparison of entire soil profiles and soil control sections. Journal of Environmental Management, 155, 219-228.

Superfund Record of Decision (EPA Region 4): Milan Army Ammunition Plant, Milan, TN, March 11, 1998

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

NONE

1998-09-01

This decision document presents the selected action for the Salvage Yard, Former Ammunition Burnout Area (ABA), and Sanitary Landfill at MLAAP, located in Gibson and Carroll Counties, TN. This ROD addresses the final response action planned for the Salvage Yard, Former ABA, and Sanitary Landfill, including soil and groundwater. NFA is the selected remedy for soil and groundwater at the Salvage Yard, Former ABA, and Sanitary landfill. The selected remedy manages the risk to acceptable levels for both human health and the environment and is the final action planned.

Soil Fertility Evaluation and Land Management of Dryland Farming at Tegallalang Sub-District, Gianyar Regency, Bali, Indonesia

NASA Astrophysics Data System (ADS)

Sardiana, I. K.; Susila, D.; Supadma, A. A.; Saifulloh, M.

2017-12-01

The landuse of Tegallalang Subdistrict is dominated by dryland farming. The practice of cultivation on agricultural dryland that ignores the carrying capacity of the environment can lead to land degradation that makes the land vulnerable to the deterioration of soil fertility. Soil fertility evaluation and land management of dryland farming in Tegallalang Sub-district, Gianyar Regency were aimed at (1) identifying the soil fertility and it’s respective limiting factors, (2) mapping the soil fertility using Geographic Information Systems (GIS) and (3) developing land management for dryland farming in Tegallalang Sub-district. This research implementing explora-tory method which followed by laboratory analysis. Soil samples were taken on each homogene-ous land units which developed by overlay of slope, soil type, and land use maps. The following soil fertility were measured, such as CEC, base saturation, P2O5, K- Total and C-Organic. The values of soil fertility were mapping using QGIS 2.18.7 and refer to land management evaluation. The results showed that the soil fertility in the research area considered high, and low level. The High soil fertility presents on land units at the flat to undulating slope with different land management systems (fertilizer, without fertilizer, soil tillage and without soil tillage). The low soil fertility includes land units that present on steep slope, and without land managements. The limiting factors of soil fertility were texture, C-Organic, CEC, P2O5, and K- total. It was recommended to applying organic fertilizer, Phonska, and dolomite on the farming area.

Multi-decadal impacts of grazing on soil physical and biogeochemical properties in southeast Utah

USGS Publications Warehouse

Neff, J.C.; Reynolds, R.L.; Belnap, J.; Lamothe, P.

2005-01-01

Many soils in southeastern Utah are protected from surface disturbance by biological soil crusts that stabilize soils and reduce erosion by wind and water. When these crusts are disturbed by land use, soils become susceptible to erosion. In this study, we compare a never-grazed grassland in Canyonlands National Park with two historically grazed sites with similar geologic, geomorphic, and geochemical characteristics that were grazed from the late 1800s until 1974. We show that, despite almost 30 years without livestock grazing, surface soils in the historically grazed sites have 38-43% less silt, as well as 14-51% less total elemental soil Mg, Na, P, and Mn content relative to soils never exposed to livestock disturbances. Using magnetic measurement of soil magnetite content (a proxy for the stabilization of far-traveled eolian dust) we suggest that the differences in Mg, Na, P, and Mn are related to wind erosion of soil fine particles after the historical disturbance by livestock grazing. Historical grazing may also lead to changes in soil organic matter content including declines of 60-70% in surface soil C and N relative to the never-grazed sites. Collectively, the differences in soil C and N content and the evidence for substantial rock-derived nutrient loss to wind erosion implies that livestock grazing could have long-lasting effects on the soil fertility of native grasslands in this part of southeastern Utah. This study suggests that nutrient loss due to wind erosion of soils should be a consideration for management decisions related to the long-term sustainability of grazing operations in arid environments.

Guidelines for measuring the physical, chemical, and biological condition of wilderness ecosystems

Treesearch

Douglas G Fox; J. Christopher Bernabo; Betsy Hood

1987-01-01

Guidelines include a large number of specific measures to characterize the existing condition of wilderness resources. Measures involve the atmospheric environment, water chemistry and biology, geology and soils, and flora. Where possible, measures are coordinated with existing long-term monitoring programs. Application of the measures will allow more effective...

Evaluation of soil quality in areas of cocoa cabruca, forest and multicropping in southern Bahia, Brazil

USDA-ARS?s Scientific Manuscript database

The Atlantic Rain Forest is one of the most complex natural environments of the earth and, linked with this ecosystem, the cacao-cabruca system is agroforestry cultivation with an arrangement including a range of environmental, social and economical benefits and can protect many features of the biod...

Competitive ability of tall fescue against alfalfa as a function of summer dormancy, endophyte infection and soil moisture availability

USDA-ARS?s Scientific Manuscript database

Summer-dormant cool-season grasses might be a viable component of pasture if Mediterranean and Mediterranean-type environments with relative mild winters and hot and dry summers. Management practices for summer-dormant forages are being developed, including production strategies with compatible leg...

Environment and geographic distance differ in relative importance for determining fungal community of rhizosphere and bulk soil.

PubMed

Zhang, Kaoping; Adams, Jonathan M; Shi, Yu; Yang, Teng; Sun, Ruibo; He, Dan; Ni, Yingying; Chu, Haiyan

2017-09-01

Rhizospheric fungi play major roles in both natural and agricultural ecosystems. However, little is known about the determinants of their diversity and biogeographic patterns. Here, we compared fungal communities in rhizosphere and bulk soils of wheat fields in the North China Plain. The rhizosphere had a lower fungal diversity (observed OTUs and Chao1) than bulk soil, and a distinct fungal community structure in rhizosphere compared with bulk soil. The relative importance of environmental factors and geographic distance for fungal distribution differed between rhizosphere and bulk soil. Environmental factors were the primary cause of variations in total fungal community and major fungal phyla in bulk soil. By contrast, fungal communities in soils loosely attached to roots were predictable from both environmental factors and influences of geographic distance. Communities in soils tightly attached to roots were mainly determined by geographic distance. Our results suggest that both contemporary environment processes (present-day abiotic and biotic environment characters) and historical processes (spatial isolation, dispersal limitation occurred in the past) dominate variations of fungal communities in wheat fields, but their relative importance of all these processes depends on the proximity of fungal community to the plant roots. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

Amending Jasper County, Missouri soils with biochar and ...

EPA Pesticide Factsheets

Abandoned mines and the residuals from mining across the U.S. pose a considerable, pervasive risk to human health and the environment. Many soils in the Tri-State-Mining District (TSMD), located where Missouri, Kansas and Oklahoma meet, have been affected by the residuals of historic lead and zinc mining. Here we describe a research collaboration between ORD and Region 7 to investigate the use of customized soil amendments, which will include biochar, as a tool to provide both soil remediation and reestablishment of a soil-stabilizing native plant community at sites in the TSMD. Biochar is a charcoal-like, carbon-rich, porous by-product of thermal pyrolysis or gasification. A benefit of using biochar is the ability to engineer its properties to correspond to specific soil remediation needs. Specifically, it has properties that make it well suited for use in remediating mine soils and reestablishing vegetation, with studies indicating that biochar can complex and immobilize heavy metals. This is of critical importance for mining influenced sites. However, the optimized biochar properties for the remediation of acidic mine soils are not yet fully known. Biochar can be produced to have a range of pH values, depending upon feedstock and pyrolysis or gasification conditions, and post-production activation. Therefore, this material may be used as a liming agent to raise soil pH. Additionally, some biochars have been shown to improve soil water holding capacities and

Mars aqueous chemistry experiment

NASA Technical Reports Server (NTRS)

Clark, Benton C.; Mason, Larry W.

1994-01-01

Mars Aqueous Chemistry Experiment (MACE) is designed to conduct a variety of measurements on regolith samples, encompassing mineral phase analyses, chemical interactions with H2O, and physical properties determinations. From these data, much can be learned or inferred regarding the past weathering environment, the contemporaneous soil micro-environments, and the general chemical and physical state of the Martian regolith. By analyzing both soil and duricrust samples, the nature of the latter may become more apparent. Sites may be characterized for comparative purposes and criteria could be set for selection of high priority materials on future sample return missions. The second year of the MACE project has shown significant progress in two major areas. MACE Instrument concept definition is a baseline design that has been generated for the complete MACE instrument, including definition of analysis modes, mass estimates and thermal model. The design includes multiple reagent reservoirs, 10 discrete analysis cells, sample manipulation capability, and thermal control. The MACE Measurement subsystems development progress is reported regarding measurement capabilities for aqueous ion sensing, evolved gas sensing, solution conductivity measurement, reagent addition (titration) capabilities, and optical sensing of suspended particles.

Mars aqueous chemistry experiment

NASA Astrophysics Data System (ADS)

Clark, Benton C.; Mason, Larry W.

1994-06-01

Mars Aqueous Chemistry Experiment (MACE) is designed to conduct a variety of measurements on regolith samples, encompassing mineral phase analyses, chemical interactions with H2O, and physical properties determinations. From these data, much can be learned or inferred regarding the past weathering environment, the contemporaneous soil micro-environments, and the general chemical and physical state of the Martian regolith. By analyzing both soil and duricrust samples, the nature of the latter may become more apparent. Sites may be characterized for comparative purposes and criteria could be set for selection of high priority materials on future sample return missions. The second year of the MACE project has shown significant progress in two major areas. MACE Instrument concept definition is a baseline design that has been generated for the complete MACE instrument, including definition of analysis modes, mass estimates and thermal model. The design includes multiple reagent reservoirs, 10 discrete analysis cells, sample manipulation capability, and thermal control. The MACE Measurement subsystems development progress is reported regarding measurement capabilities for aqueous ion sensing, evolved gas sensing, solution conductivity measurement, reagent addition (titration) capabilities, and optical sensing of suspended particles.

Soil Testing as a Classroom Exercise to Determine Soil-forming Processes and Soil Classification.

ERIC Educational Resources Information Center

Bencloski, Joseph W.

1980-01-01

Describes a learning activity involving correctly matching soils with environments. The activity is intended for use in college level physical geography courses. Information is presented on instructional objectives, outline of preparatory lectures, soil test exercise worksheets, procedures, laboratory setting, testing procedures, collecting and…

Vital Soil: Function, Value and Properties.

USDA-ARS?s Scientific Manuscript database

This article is a review of the book, Vital Soil: Function, Value and Properties. Soil vitality has been defined as the ability of soil ecosystems to stay in balance in a changing world. The soil environment and the life that it supports developed over centuries and millennia, but careless human ac...

Index for characterizing post-fire soil environments in temperate coniferous forests

USGS Publications Warehouse

Jain, Theresa B.; Pilliod, David S.; Graham, Russell T.; Lentile, Leigh B.; Sandquist, Jonathan E.

2012-01-01

Many scientists and managers have an interest in describing the environment following a fire to understand the effects on soil productivity, vegetation growth, and wildlife habitat, but little research has focused on the scientific rationale for classifying the post-fire environment. We developed an empirically-grounded soil post-fire index (PFI) based on available science and ecological thresholds. Using over 50 literature sources, we identified a minimum of five broad categories of post-fire outcomes: (a) unburned, (b) abundant surface organic matter ( > 85% surface organic matter), (c) moderate amount of surface organic matter ( ≥ 40 through 85%), (d) small amounts of surface organic matter ( < 40%), and (e) absence of surface organic matter (no organic matter left). We then subdivided each broad category on the basis of post-fire mineral soil colors providing a more fine-tuned post-fire soil index. We related each PFI category to characteristics such as soil temperature and duration of heating during fire, and physical, chemical, and biological responses. Classifying or describing post-fire soil conditions consistently will improve interpretations of fire effects research and facilitate communication of potential responses or outcomes (e.g., erosion potential) from fires of varying severities.

Distribution of hydrocarbon-degrading bacteria in the soil environment and their contribution to bioremediation.

PubMed

Fukuhara, Yuki; Horii, Sachie; Matsuno, Toshihide; Matsumiya, Yoshiki; Mukai, Masaki; Kubo, Motoki

2013-05-01

A real-time PCR quantification method for indigenous hydrocarbon-degrading bacteria (HDB) carrying the alkB gene in the soil environment was developed to investigate their distribution in soil. The detection limit of indigenous HDB by the method was 1 × 10(6) cells/g-soil. The indigenous HDB were widely distributed throughout the soil environment and ranged from 3.7 × 10(7) to 5.0 × 10(8) cells/g-soil, and the ratio to total bacteria was 0.1-4.3 %. The dynamics of total bacteria, indigenous HDB, and Rhodococcus erythropolis NDKK6 (carrying alkB R2) during bioremediation were analyzed. During bioremediation with an inorganic nutrient treatment, the numbers of these bacteria were slightly increased. The numbers of HDB (both indigenous bacteria and strain NDKK6) were gradually decreased from the middle stage of bioremediation. Meanwhile, the numbers of these bacteria were highly increased and were maintained during bioremediation with an organic nutrient. The organic treatment led to activation of not only the soil bacteria but also the HDB, so an efficient bioremediation was carried out.

Characterizing Hydrological Processes in Vadose Zone by Direct Infiltration Water Sampling.

NASA Astrophysics Data System (ADS)

Mori, Y.; Higashi, N.; Somura, H.; Takeda, I.; Inoue, M.

2007-12-01

These days, planted forest mountainside was roughly maintained due to the population descent and small birth rate. Because thinning operation would delayed, forest was always dark and floor weed was rare. Management induced non point source pollution like surface soil erosion was suspected, however, we could not approach to the source with the stream water analysis. Therefore, direct soil water sampling device using glass fiber capillary force was developed to examine hydrological processes in watershed. In our design, water was collected just by the capillary force and let the excess water down through so that infiltration water was truly sampled and solute concentration kept the same quality as in soil water. The experiment was conducted at two neighboring Japanese cedar planted forest under different management, i.e., south slope was roughly maintained and west slope was well maintained by thinning operation. Load discharges were higher in south slope and lower in west slope. Infiltration water analysis revealed that ion concentration was gradually decreased at west slope, however in south slope, it dropped to lower level in soil water and increased again in stream water. The trend showed that soil buffering function was poor in south slope. Actually, disk permeameter survey revealed that hydraulic conductivity was small in south slope; TOC and biological activity were lower. This entire soil environment explained the water environmental differences in stream water. Because changes in soil environment affects water environment in the future, monitoring or examination of soil environment was considered as preventive measure for environmentally sound water and solute circulation in watershed.

Microbial Community Structure in the Rhizosphere of Rice Plants

PubMed Central

Breidenbach, Björn; Pump, Judith; Dumont, Marc G.

2016-01-01

The microbial community in the rhizosphere environment is critical for the health of land plants and the processing of soil organic matter. The objective of this study was to determine the extent to which rice plants shape the microbial community in rice field soil over the course of a growing season. Rice (Oryza sativa) was cultivated under greenhouse conditions in rice field soil from Vercelli, Italy and the microbial community in the rhizosphere of planted soil microcosms was characterized at four plant growth stages using quantitative PCR and 16S rRNA gene pyrotag analysis and compared to that of unplanted bulk soil. The abundances of 16S rRNA genes in the rice rhizosphere were on average twice that of unplanted bulk soil, indicating a stimulation of microbial growth in the rhizosphere. Soil environment type (i.e., rhizosphere versus bulk soil) had a greater effect on the community structure than did time (e.g., plant growth stage). Numerous phyla were affected by the presence of rice plants, but the strongest effects were observed for Gemmatimonadetes, Proteobacteria, and Verrucomicrobia. With respect to functional groups of microorganisms, potential iron reducers (e.g., Geobacter, Anaeromyxobacter) and fermenters (e.g., Clostridiaceae, Opitutaceae) were notably enriched in the rhizosphere environment. A Herbaspirillum species was always more abundant in the rhizosphere than bulk soil and was enriched in the rhizosphere during the early stage of plant growth. PMID:26793175

The MICE facility - a new tool to study plant-soil C cycling with a holistic approach.

PubMed

Studer, Mirjam S; Künzli, Roland; Maier, Reto; Schmidt, Michael W I; Siegwolf, Rolf T W; Woodhatch, Ivan; Abiven, Samuel

2017-06-01

Plant-soil interactions are recognized to play a crucial role in the ecosystem response to climate change. We developed a facility to disentangle the complex interactions behind the plant-soil C feedback mechanisms. The MICE ('Multi-Isotope labelling in a Controlled Environment') facility consists of two climate chambers with independent control of the atmospheric conditions (light, CO 2 , temperature, humidity) and the soil environment (temperature, moisture). Each chamber holds 15 plant-soil systems with hermetical separation of the shared above ground (shoots) from the individual belowground compartments (roots, rhizosphere, soil). Stable isotopes (e.g. 13 C, 15 N, 2 H, 18 O) can be added to either compartment and traced within the whole system. The soil CO 2 efflux rate is monitored, and plant material, leached soil water and gas samples are taken frequently. The facility is a powerful tool to improve our mechanistic understanding of plant-soil interactions that drive the C cycle feedback to climate change.

Permafrost soils and carbon cycling

DOE PAGES

Ping, C. L.; Jastrow, J. D.; Jorgenson, M. T.; ...

2014-10-30

Knowledge of soils in the permafrost region has advanced immensely in recent decades, despite the remoteness and inaccessibility of most of the region and the sampling limitations posed by the severe environment. These efforts significantly increased estimates of the amount of organic carbon (OC) stored in permafrost-region soils and improved understanding of how pedogenic processes unique to permafrost environments built enormous OC stocks during the Quaternary. This knowledge has also called attention to the importance of permafrost-affected soils to the global C cycle and the potential vulnerability of the region's soil OC stocks to changing climatic conditions. In this review,more » we briefly introduce the permafrost characteristics, ice structures, and cryopedogenic processes that shape the development of permafrost-affected soils and discuss their effects on soil structures and on organic matter distributions within the soil profile. We then examine the quantity of OC stored in permafrost-region soils, as well as the characteristics, intrinsic decomposability, and potential vulnerability of this OC to permafrost thaw under a warming climate.« less

Analytical Results for Agricultural Soils Samples from a Monitoring Program Near Deer Trail, Colorado (USA)

USGS Publications Warehouse

Crock, J.G.; Smith, D.B.; Yager, T.J.B.

2009-01-01

Since late 1993, Metro Wastewater Reclamation District of Denver (Metro District, MWRD), a large wastewater treatment plant in Denver, Colorado, has applied Grade I, Class B biosolids to about 52,000 acres of nonirrigated farmland and rangeland near Deer Trail, Colorado, USA. In cooperation with the Metro District in 1993, the U.S. Geological Survey (USGS) began monitoring groundwater at part of this site. In 1999, the USGS began a more comprehensive monitoring study of the entire site to address stakeholder concerns about the potential chemical effects of biosolids applications to water, soil, and vegetation. This more comprehensive monitoring program has recently been extended through 2010. Monitoring components of the more comprehensive study include biosolids collected at the wastewater treatment plant, soil, crops, dust, alluvial and bedrock groundwater, and stream bed sediment. Soils for this study were defined as the plow zone of the dry land agricultural fields - the top twelve inches of the soil column. This report presents analytical results for the soil samples collected at the Metro District farm land near Deer Trail, Colorado, during three separate sampling events during 1999, 2000, and 2002. Soil samples taken in 1999 were to be a representation of the original baseline of the agricultural soils prior to any biosolids application. The soil samples taken in 2000 represent the soils after one application of biosolids to the middle field at each site and those taken in 2002 represent the soils after two applications. There have been no biosolids applied to any of the four control fields. The next soil sampling is scheduled for the spring of 2010. Priority parameters for biosolids identified by the stakeholders and also regulated by Colorado when used as an agricultural soil amendment include the total concentrations of nine trace elements (arsenic, cadmium, copper, lead, mercury, molybdenum, nickel, selenium, and zinc), plutonium isotopes, and gross alpha and beta activity (Colorado Department of Public Health and Environment, Hazardous Materials and Waste Management Division, 1997; Colorado Department of Public Health and Environment,1998; U.S. Environmental Protection Agency, 1993). Since these were the identified priority parameters for the biosolids, the soils have the same set of priority parameters. Although the composite soils' priority analytes have been reported earlier to Metro District, the remaining elemental datasets for both the composite soils samples and selected fields' individual subsamples' data are presented here for the first time. More information about the other monitoring components is presented elsewhere in the literature (http://co.water.usgs.gov/projects/CO406/CO406.html). In general, the objective of each component of the study was to determine whether concentrations of priority parameters (1) were higher than regulatory limits, (2) were increasing with time, and(or) (3) were significantly higher in biosolids-applied areas than in a similar farmed area where biosolids were not applied. The method chosen for sampling the soils proved to be an efficient and reliable representation of the average composition of each field. This was shown by analyzing individual subsamples, averaging the resulting values, and then comparing the values to the composited samples' values. The soil chemistry shows distinct differences between the two sites, most likely due to the different underlying parent material. Biosolids data were used to compile an inorganic-chemical biosolids signature that can be contrasted with the geochemical signature of the agricultural soils for this site. The biosolids signature and an understanding of the geology and hydrology of the site can be used to separate biosolids effects from natural geochemical effects. Elements of particular interest for a biosolids signature after application in the soils include bismuth, copper, silver, mercury, and phosphorus. This signat

Potential role of soil properties in the spread of CWD in western Canada.

PubMed

Kuznetsova, Alsu; McKenzie, Debbie; Banser, Pamela; Siddique, Tariq; Aiken, Judd M

2014-01-01

Chronic wasting disease (CWD) is a horizontally transmissible prion disease of free ranging deer, elk and moose. Recent experimental transmission studies indicate caribou are also susceptible to the disease. CWD is present in southeast Alberta and southern Saskatchewan. This CWD-endemic region is expanding, threatening Manitoba and areas of northern Alberta and Saskatchewan, home to caribou. Soil can serve as a stable reservoir for infectious prion proteins; prions bound to soil particles remain infectious in the soils for many years. Soils of western Canada are very diverse and the ability of CWD prions to bind different soils and the impact of this interaction on infectivity is not known. In general, clay-rich soils may bind prions avidly and enhance their infectivity comparable to pure clay mineral montmorillonite. Organic components of soils are also diverse and not well characterized, yet can impact prion-soil interaction. Other important contributing factors include soil pH, composition of soil solution and amount of metals (metal oxides). In this review, properties of soils of the CWD-endemic region in western Canada with its surrounding terrestrial environment are described and used to predict bioavailability and, thus, potential spread of CWD. The major soils in the CWD-endemic region of Alberta and Saskatchewan are Chernozems, present in 60% of the total area; they are generally similar in texture, clay mineralogy and soil organic matter content, and can be characterized as clay loamy, montmorillonite (smectite) soils with 6-10% organic carbon. The greatest risk of CWD spread in western Canada relates to clay loamy, montmorillonite soils with humus horizon. Such soils are predominant in the southern region of Alberta, Saskatchewan and Manitoba, but are less common in northern regions of the provinces where quartz-illite sandy soils with low amount of humus prevail.

Profiling Nematode Communities in Unmanaged Flowerbed and Agricultural Field Soils in Japan by DNA Barcode Sequencing

PubMed Central

Morise, Hisashi; Miyazaki, Erika; Yoshimitsu, Shoko; Eki, Toshihiko

2012-01-01

Soil nematodes play crucial roles in the soil food web and are a suitable indicator for assessing soil environments and ecosystems. Previous nematode community analyses based on nematode morphology classification have been shown to be useful for assessing various soil environments. Here we have conducted DNA barcode analysis for soil nematode community analyses in Japanese soils. We isolated nematodes from two different environmental soils of an unmanaged flowerbed and an agricultural field using the improved flotation-sieving method. Small subunit (SSU) rDNA fragments were directly amplified from each of 68 (flowerbed samples) and 48 (field samples) isolated nematodes to determine the nucleotide sequence. Sixteen and thirteen operational taxonomic units (OTUs) were obtained by multiple sequence alignment from the flowerbed and agricultural field nematodes, respectively. All 29 SSU rDNA-derived OTUs (rOTUs) were further mapped onto a phylogenetic tree with 107 known nematode species. Interestingly, the two nematode communities examined were clearly distinct from each other in terms of trophic groups: Animal predators and plant feeders were markedly abundant in the flowerbed soils, in contrast, bacterial feeders were dominantly observed in the agricultural field soils. The data from the flowerbed nematodes suggests a possible food web among two different trophic nematode groups and plants (weeds) in the closed soil environment. Finally, DNA sequences derived from the mitochondrial cytochrome oxidase c subunit 1 (COI) gene were determined as a DNA barcode from 43 agricultural field soil nematodes. These nematodes were assigned to 13 rDNA-derived OTUs, but in the COI gene analysis were assigned to 23 COI gene-derived OTUs (cOTUs), indicating that COI gene-based barcoding may provide higher taxonomic resolution than conventional SSU rDNA-barcoding in soil nematode community analysis. PMID:23284767

Soil respiration in the cold desert environment of the Colorado Plateau (USA): Abiotic regulators and thresholds

USGS Publications Warehouse

Fernandez, D.P.; Neff, J.C.; Belnap, J.; Reynolds, R.L.

2006-01-01

Decomposition is central to understanding ecosystem carbon exchange and nutrient-release processes. Unlike mesic ecosystems, which have been extensively studied, xeric landscapes have received little attention; as a result, abiotic soil-respiration regulatory processes are poorly understood in xeric environments. To provide a more complete and quantitative understanding about how abiotic factors influence soil respiration in xeric ecosystems, we conducted soil- respiration and decomposition-cloth measurements in the cold desert of southeast Utah. Our study evaluated when and to what extent soil texture, moisture, temperature, organic carbon, and nitrogen influence soil respiration and examined whether the inverse-texture hypothesis applies to decomposition. Within our study site, the effect of texture on moisture, as described by the inverse texture hypothesis, was evident, but its effect on decomposition was not. Our results show temperature and moisture to be the dominant abiotic controls of soil respiration. Specifically, temporal offsets in temperature and moisture conditions appear to have a strong control on soil respiration, with the highest fluxes occurring in spring when temperature and moisture were favorable. These temporal offsets resulted in decomposition rates that were controlled by soil moisture and temperature thresholds. The highest fluxes of CO2 occurred when soil temperature was between 10 and 16??C and volumetric soil moisture was greater than 10%. Decomposition-cloth results, which integrate decomposition processes across several months, support the soil-respiration results and further illustrate the seasonal patterns of high respiration rates during spring and low rates during summer and fall. Results from this study suggest that the parameters used to predict soil respiration in mesic ecosystems likely do not apply in cold-desert environments. ?? Springer 2006.

Use of zeolite to neutralise nickel in a soil environment.

PubMed

Boros-Lajszner, Edyta; Wyszkowska, Jadwiga; Kucharski, Jan

2017-12-30

Nickel is a heavy metal which is a stable soil pollutant which is difficult to remediate. An attempt to reduce its impact on the environment can be made by changing its solubility. The right level of hydrogen ions and the content of mineral and organic colloids are crucial in this regard. Therefore, methods to neutralise heavy metals in soil are sought. There are no reports in the literature on the possibility of using minerals in the detoxication of a soil environment contaminated with metals. It is important to fill the gap in research on the effect of zeolites on the microbiological, biochemical and physicochemical properties of soils under pressure from heavy metals. Therefore, a pot experiment was conducted on two soils which examined the effect of various levels of contamination of soil with nickel on the activity of soil enzymes, physical and chemical properties and growth and development of plants. An alleviating effect of zeolite Bio.Zeo.S.01 on the negative impact of nickel on the soil and a plant (oats) was examined. The enzyme activity and the oat yield were found to be significantly and negatively affected by an excess of nickel in the soil, regardless of the soil type. The metal was accumulated more in the oat roots than in the above-ground parts. An addition of zeolite decreased the level of accumulation of nickel in oats grown only on sandy-silty loam. Zeolite Bio.Zeo.S.01 used in the study only slightly alleviated the negative effect of nickel on the biochemical properties of soil. Therefore, its usability in the remediation of soil contaminated with nickel is small.

An analysis of the dissipation of pharmaceuticals under thirteen different soil conditions.

PubMed

Kodešová, Radka; Kočárek, Martin; Klement, Aleš; Golovko, Oksana; Koba, Olga; Fér, Miroslav; Nikodem, Antonín; Vondráčková, Lenka; Jakšík, Ondřej; Grabic, Roman

2016-02-15

The presence of human and veterinary pharmaceuticals in the environment is recognized as a potential threat. Pharmaceuticals have the potential to contaminate soils and consequently surface and groundwater. Knowledge of contaminant behavior (e.g., sorption onto soil particles and degradation) is essential when assessing contaminant migration in the soil and groundwater environment. We evaluated the dissipation half-lives of 7 pharmaceuticals in 13 soils. The data were evaluated relative to the soil properties and the Freundlich sorption coefficients reported in our previous study. Of the tested pharmaceuticals, carbamazepine had the greatest persistence (which was mostly stable), followed by clarithromycin, trimethoprim, metoprolol, clindamycin, sulfamethoxazole and atenolol. Pharmaceutical persistence in soils was mostly dependent on the soil-type conditions. In general, lower average dissipation half-lives and variability (i.e., trimethoprim, sulfamethoxazole, clindamycin, metoprolol and atenolol) were found in soils of better quality (well-developed structure, high nutrition content etc.), and thus, probably better microbial conditions (i.e., Chernozems), than in lower quality soil (Cambisols). The impact of the compound sorption affinity onto soil particles on their dissipation rate was mostly negligible. Although there was a positive correlation between compound dissipation half-life and Freundlich sorption coefficient for clindamycin (R=0.604, p<0.05) and sulfamethoxazole (R=0.822, p<0.01), the half-life of sulfamethoxazole also decreased under better soil-type conditions. Based on the calculated dissipation and sorption data, carbamazepine would be expected to have the greatest potential to migrate in the soil water environment, followed by sulfamethoxazole, trimethoprim and metoprolol. The transport of clindamycin, clarithromycin and atenolol through the vadose zone seems less probable. Copyright © 2015 Elsevier B.V. All rights reserved.

Validating the use of 137Cs and 210Pbex measurements to estimate rates of soil loss from cultivated land in southern Italy.

PubMed

Porto, Paolo; Walling, Des E

2012-04-01

Soil erosion represents an important threat to the long-term sustainability of agriculture and forestry in many areas of the world, including southern Italy. Numerous models and prediction procedures have been developed to estimate rates of soil loss and soil redistribution, based on the local topography, hydrometeorology, soil type and land management. However, there remains an important need for empirical measurements to provide a basis for validating and calibrating such models and prediction procedures as well as to support specific investigations and experiments. In this context, erosion plots provide useful information on gross rates of soil loss, but are unable to document the efficiency of the onward transfer of the eroded sediment within a field and towards the stream system, and thus net rates of soil loss from larger areas. The use of environmental radionuclides, particularly caesium-137 ((137)Cs) and excess lead-210 ((210)Pb(ex)), as a means of estimating rates of soil erosion and deposition has attracted increasing attention in recent years and the approach has now been recognised as possessing several important advantages. In order to provide further confirmation of the validity of the estimates of longer-term erosion and soil redistribution rates provided by (137)Cs and (210)Pb(ex) measurements, there is a need for studies aimed explicitly at validating the results obtained. In this context, the authors directed attention to the potential offered by a set of small erosion plots located near Reggio Calabria in southern Italy, for validating estimates of soil loss provided by (137)Cs and (210)Pb(ex) measurements. A preliminary assessment suggested that, notwithstanding the limitations and constraints involved, a worthwhile investigation aimed at validating the use of (137)Cs and (210)Pb(ex) measurements to estimate rates of soil loss from cultivated land could be undertaken. The results demonstrate a close consistency between the measured rates of soil loss and the estimates provided by the (137)Cs and (210)Pb(ex) measurements and can therefore been seen as validating the use of these fallout radionuclides to document soil erosion rates in that environment. Further studies are clearly required to exploit other opportunities for validation in contrasting environments and under different land use conditions. Copyright © 2011 Elsevier Ltd. All rights reserved.

Alkylphenol ethoxylates and alkylphenols--update information on occurrence, fate and toxicity in aquatic environment.

PubMed

Kovarova, J; Blahova, J; Divisova, L; Svobodova, Z

2013-01-01

Alkylphenols and their precursors, alkylphenol etoxylates, are a group of manmade chemicals used mainly as surfactants in domestic and industrial applications worldwide. It has been well established that they have endocrine disruption activity, hepatotoxic, genotoxic and other negative effects on animal and human health. In spite of the effort to reduce their use, they persist in the environment not only in industrial but also in remote regions, and were detected in the variety of natural matrices including air, water, soil as well as food products, and human blood and urine worldwide. This article summarizes their occurrence, fate in natural conditions, and toxicity including mode of action. A subject of our concern was the aquatic environment as the most important reservoir and target of their deleterious impact.

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

M.A. Wasiolek

Inhalation exposure pathway modeling has recently been investigated as one of the tasks of the BIOPROTA Project (BIOPROTA 2005). BIOPROTA was set up to address the key uncertainties in long term assessments of contaminant releases into the environment arising from radioactive waste disposal. Participants of this international Project include national authorities and agencies, both regulators and operators, with responsibility for achieving safe and acceptable radioactive waste management. The objective of the inhalation task was to investigate the calculation of doses arising from inhalation of particles suspended from soils within which long-lived radionuclides, particularly alpha emitters, had accumulated. It was recognizedmore » that site-specific conditions influence the choice of conceptual model and input parameter values. Therefore, one of the goals of the task was to identify the circumstances in which different processes included in specific inhalation exposure pathway models were important. This paper discusses evaluation of processes and modeling assumptions specific to the proposed repository at Yucca Mountain as compared to the typical approaches and other models developed for different assessments and project specific contexts. Inhalation of suspended particulates that originate from contaminated soil is an important exposure pathway, particularly for exposure to actinides such as uranium, neptunium and plutonium. Radionuclide accumulation in surface soil arises from irrigation of soil with contaminated water over many years. The level of radionuclide concentration in surface soil depends on the assumed duration of irrigation. Irrigation duration is one of the parameters used on biosphere models and it depends on a specific assessment context. It is one of the parameters addressed in this paper from the point of view of assessment context for the proposed repository at Yucca Mountain. The preferred model for the assessment of inhalation exposure uses atmospheric mass loading approach, which is based on the mass of airborne particulates per unit volume of air that is inhaled by the receptor. This type of model was used by the majority of the BIOPROTA inhalation task participants and is also used in the Yucca Mountain model. Although the mass loading model is conceptually straightforward, there are some considerations that need to be included when using this model. Small particles have larger surface to volume ratio than large particles and this ratio increases in inverse proportion to the particle size. This is particularly important for elements such as plutonium, which have high sorption coefficients, and thus are preferentially attached to small particles of soil. Suspended particulates originating from soil are composed of particles smaller than average soil particles and thus, on average, have larger available surface area, and consequently activity, per unit mass than that of soil. The increase of radionuclide concentration of suspended particulates compared with that of underlying soil is quantified in terms of the enhancement factor, which is included in the inhalation model for the Yucca Mountain repository. In this paper, the use of the enhancement factor in the inhalation exposure models is discussed. Then, enhancement factor values used in the Yucca Mountain model are discussed from the perspective of site-specific conditions as well as the microenvironmental approach to modeling inhalation exposure of the receptor: The receptor can spend specified time in several environments, each of them characterized by an occupancy time, suspended particulate level, enhancement factor and breathing rate. The environment where inhalation exposure is the highest is associated with the receptor being active outdoors and involved in activities that generate high levels of dust by using farm equipment, walking, or conducting other outdoor activities. I n summary, it is important to recognize that site-specific conditions play an important role in constructing conceptual and mathematical models of inhalation exposure.« less

An Interactive Real-time Decision Support System for Leachate Irrigation on Evapotranspiration Landfill Covers

NASA Astrophysics Data System (ADS)

Wang, Y.

2015-12-01

Landfill disposal is still the most common and economical practice for municipal solid waste in most countries. However, heavily polluted leachate generated by excess rainwater percolating through the landfill waste is the major drawback of this practice. Evapotranspiration (ET) cover systems are increasingly being used as alternative cover systems to minimize percolation by evapotranspiration. Leachate recirculation is one of the least expensive options for leachate treatment. The combination of ET cover systems and leachate recirculation can be an economical and environment-friendly practice for landfill leachate management. An interactive real-time decision support system is being developed to better manage leachate irrigation using historical and forecasting weather data, and real time soil moisture data. The main frame of this system includes soil water modules, and plant-soil modules. An inverse simulation module is also included to calibrate certain parameters based on observed data when necessary. It would be an objectives-oriented irrigation management tool to minimize landfill operation costs and negative environmental impacts.

The uniqueness of humic substances in each of soil, stream and marine environments

USGS Publications Warehouse

Malcolm, R.L.

1990-01-01

Definitive compositional differences are shown to exist for both fulvic acids and humic acids from soil, stream and marine environments by five different methods (1H and 13C NMR spectroscopy, 14C age and ?? 13C isotopic analyses, amino acid analyses and pyrolysis-mass spectrometry). Definitive differences are also found between fulvic acids and humic acids within each environment. These differences among humic substances from various sources are more readily discerned because the method employed for the isolation of humic substances from all environments excludes most of the non-humic components and results in more purified humic isolates from water and soils. The major compositional aspects of fulvic acids and humic acids which determine the observed characteristic differences in each environment are the amounts and compositions of saccharide, phenolic, methoxyl, aromatic, hydrocarbon, amino acid and nitrogen moieties.

Environmental stochasticity controls soil erosion variability

PubMed Central

Kim, Jongho; Ivanov, Valeriy Y.; Fatichi, Simone

2016-01-01

Understanding soil erosion by water is essential for a range of research areas but the predictive skill of prognostic models has been repeatedly questioned because of scale limitations of empirical data and the high variability of soil loss across space and time scales. Improved understanding of the underlying processes and their interactions are needed to infer scaling properties of soil loss and better inform predictive methods. This study uses data from multiple environments to highlight temporal-scale dependency of soil loss: erosion variability decreases at larger scales but the reduction rate varies with environment. The reduction of variability of the geomorphic response is attributed to a ‘compensation effect’: temporal alternation of events that exhibit either source-limited or transport-limited regimes. The rate of reduction is related to environment stochasticity and a novel index is derived to reflect the level of variability of intra- and inter-event hydrometeorologic conditions. A higher stochasticity index implies a larger reduction of soil loss variability (enhanced predictability at the aggregated temporal scales) with respect to the mean hydrologic forcing, offering a promising indicator for estimating the degree of uncertainty of erosion assessments. PMID:26925542

Influence of management practices on C stabilization pathways in agricultural volcanic ash soils (Canary Islands, Spain)

NASA Astrophysics Data System (ADS)

Hernandez, Zulimar; María Álvarez, Ana; Carral, Pilar; de Figueiredo, Tomas; Almendros, Gonzalo

2014-05-01

Although C stabilization mechanisms in agricultural soils are still controversial [1], a series of overlapped pathways has been suggested [2] such as: i) insolubilization of low molecular weight precursors of soil organic matter (SOM) with reactive minerals through physical and chemical bonding, ii) selective accumulation of biosynthetic substances which are recalcitrant because of its inherent chemical composition, and iii) preservation and furter diagenetic transformation of particulate SOM entrapped within resistant microaggregates, where diffusion of soil enzymes is largely hampered. In some environments where carbohydrate and N compounds are not readily biodegraded, e.g., with water saturated micropores, an ill-known C stabilization pathway may involve the formation of Maillard's reaction products [3]. In all cases, these pathways converge in the formation of recalcitrant macromolecular substances, sharing several properties with the humic acid (HA) fraction [4]. In template forests, the selective preservation and further microbial reworking of plant biomass has been identified as a prevailing mechanism in the accumulation of recalcitrant SOM forms [5]. However, in volcanic ash soils with intense organomineral interactions, condensation reactions of low molecular weight precursors with short-range minerals may be the main mechanism [6]. In order to shed some light about the effect of agricultural management on soil C stabilization processes on volcanic ash soils, the chemical composition of HA and some structural proxies of SOM informing on its origin and potential resistance to biodegradation, were examined in 30 soils from Canary Islands (Spain) by visible, infrared (IR) and 13C nuclear magnetic resonance (NMR) spectroscopies, elementary analysis and pyrolytic techniques. The results of multivariate treatments, suggested at least three simultaneous C stabilization biogeochemical trends: i) diagenetic alteration of plant biomacromolecules in soils receiving periodical inputs of manures. This includes accumulation of slightly transformed material in scenarios of high C mineralization rates, such are in vitrandic soils. ii) Accumulation of resilient organo-mineral complexes in non andic-soils with crystalline minerals and probable inputs of pyrogenic C in the past. Finally, iii) accumulation of aliphatic structures, such as carbohydrate- and N-rich macromolecules, leading to HAs with characteristics in common with those formed in aquatic environments. The formation of these HAs could be favoured by microbial activity in andic Anthrosols, and would define a specific type of soil C stabilization mechanism of aliphatic compounds encapsulated in nanoparticle-size soil pores, where persistent hydromorphic conditions were favoured by amorphous gels in volcanic ash soils. [1] Lal, R., 2004. Mitigation and Adaptation Strategies for Global Change 12, 303-322. [2] Stevenson, F.J., 1994. Humus Chemistry: Genesis, composition, reactions. 2nd ed. Wiley, New York. [3] Ellis, G.P., 1959. Advances in Carbohydrate Chemistry 14, 63-134. [4] Almendros, G., 2008. Humic substances. In: Cheswort, W. (Ed.), Encyclopedia of Soil Science, Springer, Dordretch, pp. 97-99. [5] Kögel-Knabner, I., Hatcher, P.G., Tegelaar, E.W., de Leeuw J.W., 1992. The Science of the Total Environment 113, 89-105. [6] Hernández, Z., Almendros, G., Carral, P., Álvarez, A., Knicker, H., Pérez-Trujillo, J.P., 2012. European Journal of Soil Science 63, 603-615.

Natural Remediation at Savannah River Site

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

Lewis, C. M.; Van Pelt, R.

2002-02-25

Natural remediation is a general term that includes any technology or strategy that takes advantage of natural processes to remediate a contaminated media to a condition that is protective of human health and the environment. Natural remediation techniques are often passive and minimally disruptive to the environment. They are generally implemented in conjunction with traditional remedial solutions for source control (i.e., capping, stabilization, removal, soil vapor extraction, etc.). Natural remediation techniques being employed at Savannah River Site (SRS) include enhanced bio-remediation, monitored natural attenuation, and phytoremediation. Enhanced bio-remediation involves making nutrients available and conditions favorable for microbial growth. With propermore » precautions and feeding, the naturally existing microbes flourish and consume the contaminants. Case studies of enhanced bio-remediation include surface soils contaminated with PCBs and pesticides, and Volatile Organic Compound (VOC) contamination in both the vadose zone and groundwater. Monitored natural attenuation (MNA) has been selected as the preferred alternative for groundwater clean up at several SRS waste units. Successful implementation of MNA has been based on demonstration that sources have been controlled, groundwater modeling that indicates that plumes will not expand or reach surface water discharge points at levels that exceed regulatory limits, and continued monitoring. Phytoremediation is being successfully utilized at several SRS waste units. Phytoremediation involves using plants and vegetation to uptake, break down, or manage contaminants in groundwater or soils. Case studies at SRS include managing groundwater plumes of tritium and VOCs with pine trees that are native to the area. Significant decreases in tritium discharge to a site stream have been realized in one phytoremediation project. Studies of other vegetation types, methods of application, and other target contaminants are underway.« less

N2O and N2 emissions from contrasting soil environments - interactive effects of soil nitrogen, hydrology and microbial communities

NASA Astrophysics Data System (ADS)

Christiansen, Jesper; Elberling, Bo; Ribbons, Relena; Hedo, Javier; José Fernández Alonso, Maria; Krych, Lukasz; Sandris Nielsen, Dennis; Kitzler, Barbara

2016-04-01

Reactive nitrogen (N) in the environment has doubled relative to the natural global N cycle with consequences for biogeochemical cycling of soil N. Also, climate change is expected to alter precipitation patterns and increase soil temperatures which in Arctic environments may accelerate permafrost thawing. The combination of changes in the soil N cycle and hydrological regimes may alter microbial transformations of soil N with unknown impacts on N2O and N2 emissions from temperate and Arctic soils. We present the first results of soil N2O and N2 emissions, chemistry and microbial communities over soil hydrological gradients (upslope, intermediate and wet) across a global N deposition gradient. The global gradient covered an N-limited high Arctic tundra (Zackenberg-ZA), a pacific temperate rain forest (Vancouver Island-VI) and an N saturated forest in Austria (Klausenleopoldsdorf-KL). The N2O and N2 emissions were measured from intact cores at field moisture in a He-atmosphere system. Extractable NH4+ and NO3-, organic and microbial C and N and potential enzyme-activities were determined on soil samples. Soil genomic DNA was subjected to MiSeq-based tag-encoded 16S rRNA and ITS gene amplicon sequencing for the bacterial and fungal community structure. Similar soil moisture levels were observed for the upslope, intermediate and wet locations at ZA, VI and KL, respectively. Extractable NO3- was highest at the N rich KL and lowest at ZA and showed no trend with soil moisture similar to NH4+. At ZA and VI soil NH4+ was higher than NO3- indicating a tighter N cycling. N2O emissions increased with soil moisture at all sites. The N2O emissions for the wet locations ranked similarly to NO3- with the largest response to soil moisture at KL. N2 emissions were remarkably similar across the sites and increased with soil wetness. Microbial C and N also increased with soil moisture and were overall lowest at the N rich KL site. The potential activity of protease enzyme was site dependent indicating different capacities for N turnover of the microbial community. These findings indicate a positive feedback between increased soil N and wetter soils that promotes N2O relative to N2. These interactions may be site specific due to differential functional diversity of the soil microbial community. Future characterization of the community structure will shed light on the link between the role of microbial groups related to soil N cycling pathways and the resultant partitioning of N2O and N2 emissions in these contrasting environments.

Subsurface Salts in Antarctic Dry Valley Soils

NASA Technical Reports Server (NTRS)

Englert, P.; Bishop, J. L.; Gibson, E. K.; Koeberl, C.

2013-01-01

The distribution of water-soluble ions, major and minor elements, and other parameters were examined to determine the extent and effects of chemical weathering on cold desert soils. Patterns at the study sites support theories of multiple salt forming processes, including marine aerosols and chemical weathering of mafic minerals. Periodic solar-mediated ionization of atmospheric nitrogen might also produce high nitrate concentrations found in older sediments. Chemical weathering, however, was the major contributor of salts in Antarctic Dry Valleys. The Antarctic Dry Valleys represent a unique analog for Mars, as they are extremely cold and dry desert environments. Similarities in the climate, surface geology, and chemical properties of the Dry Valleys to that of Mars imply the possible presence of these soil formation mechanisms on Mars, other planets and icy satellites.

Modeled and monitored variation in space and time of PCB-153 concentrations in air, sediment, soil and aquatic biota on a European scale.

PubMed

Hauck, Mara; Huijbregts, Mark A J; Hollander, Anne; Hendriks, A Jan; van de Meent, Dik

2010-08-15

We evaluated various modeling options for estimating concentrations of PCB-153 in the environment and in biota across Europe, using a nested multimedia fate model coupled with a bioaccumulation model. The most detailed model set up estimates concentrations in air, soil, fresh water sediment and fresh water biota with spatially explicit environmental characteristics and spatially explicit emissions to air and water in the period 1930-2005. Model performance was evaluated with the root mean square error (RMSE(log)), based on the difference between estimated and measured concentrations. The RMSE(log) was 5.4 for air, 5.6-6.3 for sediment and biota, and 5.5 for soil in the most detailed model scenario. Generally, model estimations tended to underestimate observed values for all compartments, except air. The decline in observed concentrations was also slightly underestimated by the model for the period where measurements were available (1989-2002). Applying a generic model setup with averaged emissions and averaged environmental characteristics, the RMSE(log) increased to 21 for air and 49 for sediment. For soil the RMSE(log) decreased to 3.5. We found that including spatial variation in emissions was most relevant for all compartments, except soil, while including spatial variation in environmental characteristics was less influential. For improving predictions of concentrations in sediment and aquatic biota, including emissions to water was found to be relevant as well. Copyright 2009 Elsevier B.V. All rights reserved.

Quantifying the Global Nitrous Oxide Emissions Using a Trait-based Biogeochemistry Model

NASA Astrophysics Data System (ADS)

Zhuang, Q.; Yu, T.

2017-12-01

Nitrogen is an essential element for the global biogeochemical cycle. It is a key nutrient for organisms and N compounds including nitrous oxide significantly influence the global climate. The activities of bacteria and archaea are responsible for the nitrification and denitrification in a wide variety of environments, so microbes play an important role in the nitrogen cycle in soils. To date, most existing process-based models treated nitrification and denitrification as chemical reactions driven by soil physical variables including soil temperature and moisture. In general, the effect of microbes on N cycling has not been modeled in sufficient details. Soil organic carbon also affects the N cycle because it supplies energy to microbes. In my study, a trait-based biogeochemistry model quantifying N2O emissions from the terrestrial ecosystems is developed based on an extant process-based model TEM (Terrestrial Ecosystem Model). Specifically, the improvement to TEM includes: 1) Incorporating the N fixation process to account for the inflow of N from the atmosphere to biosphere; 2) Implementing the effects of microbial dynamics on nitrification process; 3) fully considering the effects of carbon cycling on N nitrogen cycling following the principles of stoichiometry of carbon and nitrogen in soils, plants, and microbes. The difference between simulations with and without the consideration of bacterial activity lies between 5% 25% based on climate conditions and vegetation types. The trait based module allows a more detailed estimation of global N2O emissions.

The relationship between soil management and the Sustainable Development Goals: the case of global banana production

NASA Astrophysics Data System (ADS)

Stoorvogel, Jetse; Segura, Rafael; Erima, Rockefeller

2017-04-01

The Sustainable Development Goals (SDGs) are a good example of the increasing demand on our soil resources. Our soil resources play a central role in multiple SDGs while talking about poverty (SDG 1), food security (SDG 2), clean energy through biofuels (SDG 7), climate mitigation (SDG 13), and land degradation (SDG 15). This means that basic decisions on soil management are now placed in the context of multiple soil functions. A good example is the global production of bananas and plantains with a total harvested area of almost 10 million ha. While the export bananas played a central role in economic development, an even larger share of the production plays a role in food security. Nevertheless, the production is also criticized due the intensive use of agricultural chemicals (fertilizers and pesticides) and the risk of soil degradation in the monoculture plantations. Decisions on soil management are context specific and depending on the environment. In this study we will analyse and discuss three production environments from the Philippines, Uganda, and Costa Rica. The role of the SDGs in the regions is very different. Where SDG 1 and SDG15 play an important role in the Costa Rican situation, SDG 2 is more important in Uganda and the Philippines. Decisions on soil management strongly depend on the agro-ecology with the available technological packages. The technological packages include low external input farming, organic farming, precision agriculture, and so-called best management practices. While producers take decisions at the field and farm level, we are now increasingly forced for joined action at the regional level with the rapid spread of highly virulent crop diseases. The SDGs have major consequences for soil management but this study shows that, at the same time, they cannot be translated one-to-one to the farm level at which the management decisions are taken. Therefore, off-farm effects and externalities are often not considered in farm management except if they are explicitly being targeted by policies or other interventions. Specific attention is required to analyse the aggregated effect of soil management decisions at the regional level.

Risk Assessment Report, Davis Global Communications Site

DTIC Science & Technology

1994-02-23

trivalent chromium . Hexavalent chromium typically is unstable in soil and readily mobilized in both acid and alkaline soils (Bartlett and James, 1979...Environ. Qual. 8: 31. 1 Bartlett, R. J., and J. M. Kimble. 1976a. "Behavior of chromium in soils. I. Trivalent forms." J Environ. QuaL 5: 379-382. 3 i...Background data were not available from these sources for antimony, cadmium, hexavalent chromium , thallium, and silver. Other literature sources, discussed

Soil physics: a Moroccan perspective

NASA Astrophysics Data System (ADS)

Lahlou, Sabah; Mrabet, Rachid; Ouadia, Mohamed

2004-06-01

Research on environmental pollution and degradation of soil and water resources is now of highest priority worldwide. To address these problems, soil physics should be conceived as a central core to this research. This paper objectives are to: (1) address the role and importance of soil physics, (2) demonstrate progress in this discipline, and (3) present various uses of soil physics in research, environment and industry. The study of dynamic processes at and within the soil vadose zone (flow, dispersion, transport, sedimentation, etc.), and ephemeral phenomena (deformation, compaction, etc.), form an area of particular interest in soil physics. Soil physics has changed considerably over time. These changes are due to needed precision in data collection for accurate interpretation of space and time variation of soil properties. Soil physics interacts with other disciplines and sciences such as hydro(geo)logy, agronomy, environment, micro-meteorology, pedology, mathematics, physics, water sciences, etc. These interactions prompted the emergence of advanced theories and comprehensive mechanisms of most natural processes, development of new mathematical tools (modeling and computer simulation, fractals, geostatistics, transformations), creation of high precision instrumentation (computer assisted, less time constraint, increased number of measured parameters) and the scale sharpening of physical measurements which ranges from micro to watershed. The environment industry has contributed to an enlargement of many facets of soil physics. In other words, research demand in soil physics has increased considerably to satisfy specific and environmental problems (contamination of water resources, global warming, etc.). Soil physics research is still at an embryonic stage in Morocco. Consequently, soil physicists can take advantage of developments occurring overseas, and need to build up a database of soil static and dynamic properties and to revise developed models to meet our conditions. Large, but special, investment is required to promote research programs in soil physics, which consider developments in this discipline and respect Moroccan needs. These programs will be highlighted herein.

Occurrence, fate, behavior and ecotoxicological state of phthalates in different environmental matrices.

PubMed

Net, Sopheak; Sempéré, Richard; Delmont, Anne; Paluselli, Andrea; Ouddane, Baghdad

2015-04-07

Because of their large and widespread application, phthalates or phthalic acid esters (PAEs) are ubiquitous in all the environmental compartements. They have been widely detected throughout the worldwide environment. Indoor air where people spend 65-90% of their time is also highly contaminated by various PAEs released from plastics, consumer products as well as ambient suspended particulate matter. Because of their widespread application, PAEs are the most common chemicals that humans are in contact with daily. Based on various exposure mechanisms, including the ingestion of food, drinking water, dust/soil, air inhalation and dermal exposure the daily intake of PAEs may reach values as high as 70 μg/kg/day. PAEs are involved in endocrine disrupting effects, namely, upon reproductive physiology in different species of fish and mammals. They also present a variety of additional toxic effects for many other species including terrestrial and aquatic fauna and flora. Therefore, their presence in the environment has attracted considerable attention due to their potential impacts on ecosystem functioning and on public health. This paper is a synthesis of the extensive literature data on behavior, transport, fate and ecotoxicological state of PAEs in environmental matrices: air, water, sediment, sludge, wastewater, soil, and biota. First, the origins and physicochemical properties of PAEs that control the behavior, transport and fate in the environment are reviewed. Second, the compilation of data on transport and fate, adverse environmental and human health effects, legislation, restrictions, and ecotoxicological state of the environment based on PAEs is presented.

Household Anthropogenic Pollutants Against Soil Respiration Erin Murphy EnvironMentors - AggieMentor -Trent Ichiuji University of California Davis / Woodland High School

NASA Astrophysics Data System (ADS)

Murphy, E.; Ichiuji, T.

2013-12-01

Macroscopic organisms have been largely studied for carbon dioxide release rate and the effect that human development has had on these rates. However, the majority of biomass on Earth is microbes found on the Earth's surface, in the waterways and in soil. As for pollution, a single drop of weak acid is unlikely to kill on the skin of a large animal, yet this could be catastrophic to a colony of microbes. This experiment studied the effect of anthropogenic pollution on soil respiration using toxins that could easily infiltrate our soil and water systems. This project specifically examined common household chemicals in conjunction with Putah Creek soil. The tested toxins were Mobil 1 motor oil, Windex window cleaner, Ajax dish soap, and Dawn antibacterial dish soap. Six samples of Putah Creek soil were collected in jars. Four soil samples were exposed to toxins, while the remaining two were the control and glucose replicates. The control included soil damped by water, while the glucose replicate included both water and glucose. The glucose replicate was included because of its known ability to encourage respiration. A 20 mL NaCl base trap was added to each jar before being sealed. The jars were aerated once a week before titration. The 1.0 N NaCl from each jar of each week was titrated with 0.5 N HCl. The initial prediction for this experiment was that the glucose would raise the respiration levels, and that the control with no glucose would fall. Five weeks of recording the respiration levels confirmed our hypothesis that household toxins are detrimental to the soil microbial community over time. A similar experiment employed heavy metals instead of household toxins. The experiment showed that soil respiration and ATP content were strongly affected by the heavy metal content present in the soil. (Vanhala, Ahtiainen, 1994). This project will raise awareness of the negative effect of improper disposal of seemingly harmless materials. The next step of the project would be to compare the effect of similar toxins on soil respiration in different habitats. This would indicate that soil microbes are more or less acclimated to human-made toxins depending on the exposure or proximity to human development.

40 CFR 170.103 - Exceptions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Exceptions. 170.103 Section 170.103 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS WORKER PROTECTION... squirt,” “frill and spray,” chemigation, soil-incorporation, or soil-injection; (f) In a manner not...

The effect of nanoparticles and humic acid on technology critical element concentrations in aqueous solutions with soil and sand.

PubMed

Stepka, Zane; Dror, Ishai; Berkowitz, Brian

2018-01-01

As a consequence of their growing use in electronic and industrial products, increasing amounts of technology critical elements (TCEs) are being released to the environment. Currently little is known about the fate of many of these elements. Initial research on their potential environmental impact identifies TCEs as emerging contaminants. TCE movement in the environment is often governed by water systems. Research on "natural" waters so far demonstrates that TCEs tend to be associated with suspended particulate matter (SPM), which influences TCE aqueous concentrations (here: concentration of TCEs in dissolved form and attached to SPM) and transport. However, the relative potential of different types of SPM to interact with TCEs is unknown. Here we examine the potential of various types of particulate matter, namely different nanoparticles (NPs; Al 2 O 3, SiO 2 , CeO 2 , ZnO, montmorillonite, Ag, Au and carbon dots) and humic acid (HA), to impact TCE aqueous concentrations in aqueous solutions with soil and sand, and thus influence TCE transport in soil-water environments. We show that a combination of NPs and HA, and not NPs or HA individually, increases the aqueous concentrations of TCEs in soil solutions, for all tested NPs regardless of their type. TCEs retained on SPM, however, settle with time. In solutions with sand, HA alone is as influential as NPs+HA in keeping TCEs in the aqueous phase. Among NPs, Ag-NPs and Au-NPs demonstrate the highest potential for TCE transport. These results suggest that in natural soil-water environments, once TCEs are retained by soil, their partitioning to the aqueous phase by through-flowing water is unlikely. However, if TCEs are introduced to soil-water environments as part of solutions rich in NPs and HA, it is likely that NP and HA combinations can increase TCE stability in the aqueous phase and prevent their retention on soil and sand, thus facilitating TCE transport. Copyright © 2017 Elsevier B.V. All rights reserved.

The Impact of Solar Arrays on Arid Soil Hydrology: Some Numerical Simulations

NASA Astrophysics Data System (ADS)

Luo, Y.; Berli, M.; Koonce, J.; Shillito, R.; Dijkema, J.; Ghezzehei, T. A.; Yu, Z.

2016-12-01

Hot deserts are prime locations for solar energy generation but also recognized as particularly fragile environments. Minimizing the impact of facility-scale solar installations on desert environments is therefore of increasing concern. This study focuses on the impact of photovoltaic solar arrays on the water balance of arid soil underneath the array. The goal was to explore whether concentrated rainwater infiltration along the solar panel drip lines would lead to deeper infiltration and an increase in soil water storage in the long term. A two-dimensional HYDRUS model was developed to simulate rainwater infiltration into the soil within a photovoltaic solar array. Results indicate that rainwater infiltrates deeper below the drip lines compared to the areas between solar panels but only for coarse textured soil. Finer-textured soils redistribute soil moisture horizontally and the concentrating effect of solar panels on rainwater infiltration appears to be small.

Soil biogeochemistry, plant physiology and phytoremediation of cadmium contaminated soils

USDA-ARS?s Scientific Manuscript database

Cadmium (Cd) loading in soil and the environment has been accelerated worldwide due to enhanced industrialization and intensified agricultural production, particularly in the developing countries. Soil Cd pollution, resulting from both anthropogenic and geogenic sources, has posed an increasing chal...

Genomic insights into the Acidobacteria reveal strategies for their success in terrestrial environments

PubMed Central

Trojan, Daniela; Roux, Simon; Herbold, Craig; Rattei, Thomas; Woebken, Dagmar

2018-01-01

Summary Members of the phylum Acidobacteria are abundant and ubiquitous across soils. We performed a large‐scale comparative genome analysis spanning subdivisions 1, 3, 4, 6, 8 and 23 (n = 24) with the goal to identify features to help explain their prevalence in soils and understand their ecophysiology. Our analysis revealed that bacteriophage integration events along with transposable and mobile elements influenced the structure and plasticity of these genomes. Low‐ and high‐affinity respiratory oxygen reductases were detected in multiple genomes, suggesting the capacity for growing across different oxygen gradients. Among many genomes, the capacity to use a diverse collection of carbohydrates, as well as inorganic and organic nitrogen sources (such as via extracellular peptidases), was detected – both advantageous traits in environments with fluctuating nutrient environments. We also identified multiple soil acidobacteria with the potential to scavenge atmospheric concentrations of H2, now encompassing mesophilic soil strains within the subdivision 1 and 3, in addition to a previously identified thermophilic strain in subdivision 4. This large‐scale acidobacteria genome analysis reveal traits that provide genomic, physiological and metabolic versatility, presumably allowing flexibility and versatility in the challenging and fluctuating soil environment. PMID:29327410

Can nanotechnology deliver the promised benefits without negatively impacting soil microbial life?

PubMed

Dimkpa, Christian O

2014-09-01

Nanotechnology exploits the enhanced reactivity of materials at the atomic scale to improve various applications for humankind. In agriculture, potential nanotechnology applications include crop protection and fertilization. However, such benefits could come with risks for the environment: non-target plants, plant-beneficial soil microbes and other life forms could be impacted if nanoparticles (nanomaterials) contaminate the environment. This review evaluates the impact of the major metallic nanoparticles (Ag, ZnO, CuO, CeO2 , TiO2 , and FeO-based nanoparticles) on soil microbes involved in agricultural processes. The current literature indicate that in addition to population and organismal-scale effects on microbes, other subtle impacts of nanoparticles are seen in the nitrogen cycle, soil enzyme activities, and processes involved in iron metabolism, phytohormone, and antibiotic production. These effects are negative or positive, the outcome being dependent on specific nanoparticles. Collectively, published results suggest that nanotechnology portends considerable, many negative, implications for soil microbes and, thus, agricultural processes that are microbially driven. Nonetheless, the potential of plant and soil microbial processes to mitigate the bioreactivity of nanoparticles also are observed. Whereas the roots of most terrestrial plants are associated with microbes, studies of nanoparticle interactions with plants and microbes are generally conducted separately. The few studies in actual microbe-plant systems found effects of nanoparticles on the functioning of arbuscular mycorrhizal fungi, nitrogen fixation, as well as on the production of microbial siderophores in the plant rhizosphere. It is suggested that a better understanding of the agro-ecological ramifications of nanoparticles would require more in-depth interactive studies in combined plant-microbe-nanoparticle systems. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Controlled burn and immediate mobilization of potentially toxic elements in soil, from a legacy mine site in Central Victoria, Australia.

PubMed

Abraham, Joji; Dowling, Kim; Florentine, Singarayer

2018-03-01

Conducting controlled burns in fire prone areas is an efficient and economic method for forest management, and provides relief from the incidence of high severity wild fires and the consequent damage to human property and ecosystems. However, similar to wild fires, controlled burns also affect many of the physical and biogeochemical properties of the forest soil and may facilitate remobilization of potentially toxic elements (PTEs) sequestered in vegetation and soil organic matter. The objective of the current study is to investigate the mobilization of PTEs, in Central Victorian forest soils in Australia after a controlled burn. Surface soil samples were collected two days before and after the controlled burn to determine the concentration of PTEs and to examine the physicochemical properties. Results show that As, Cd, Mn, Ni and Zn concentrations increased 1.1, 1.6, 1.7, 1.1 and 1.9 times respectively in the post-burn environment, whereas the concentrations of Hg, Cr and Pb decreased to 0.7, 0.9 and 0.9 times respectively, highlighting considerable PTE mobility during and after a controlled burn. Whilst these results do not identify very strong correlations between physicochemical properties of soil and PTEs in the pre- and post-burn environments, PTEs themselves demonstrated very strong and significant correlations. The mobilization of As, Hg and other toxic elements raise potential health concerns as the number of controlled burns are projected to increase in response to climate change. Due to this increased level of PTE release and remobilization, the use of any kinds of controlled burn must be carefully considered before being used as a forest management strategy in mining-affected landscapes which include areas with high PTE concentrations. Copyright © 2017 Elsevier B.V. All rights reserved.

[Using sequential indicator simulation method to define risk areas of soil heavy metals in farmland.

PubMed

Yang, Hao; Song, Ying Qiang; Hu, Yue Ming; Chen, Fei Xiang; Zhang, Rui

2018-05-01

The heavy metals in soil have serious impacts on safety, ecological environment and human health due to their toxicity and accumulation. It is necessary to efficiently identify the risk area of heavy metals in farmland soil, which is of important significance for environment protection, pollution warning and farmland risk control. We collected 204 samples and analyzed the contents of seven kinds of heavy metals (Cu, Zn, Pb, Cd, Cr, As, Hg) in Zengcheng District of Guangzhou, China. In order to overcame the problems of the data, including the limitation of abnormal values and skewness distribution and the smooth effect with the traditional kriging methods, we used sequential indicator simulation method (SISIM) to define the spatial distribution of heavy metals, and combined Hakanson index method to identify potential ecological risk area of heavy metals in farmland. The results showed that: (1) Based on the similar accuracy of spatial prediction of soil heavy metals, the SISIM had a better expression of detail rebuild than ordinary kriging in small scale area. Compared to indicator kriging, the SISIM had less error rate (4.9%-17.1%) in uncertainty evaluation of heavy-metal risk identification. The SISIM had less smooth effect and was more applicable to simulate the spatial uncertainty assessment of soil heavy metals and risk identification. (2) There was no pollution in Zengcheng's farmland. Moderate potential ecological risk was found in the southern part of study area due to enterprise production, human activities, and river sediments. This study combined the sequential indicator simulation with Hakanson risk index method, and effectively overcame the outlier information loss and smooth effect of traditional kriging method. It provided a new way to identify the soil heavy metal risk area of farmland in uneven sampling.

Assessing the Educational Needs of Urban Gardeners and Farmers on the Subject of Soil Contamination

ERIC Educational Resources Information Center

Harms, Ashley Marie Raes; Presley, DeAnn Ricks; Hettiarachchi, Ganga M.; Thien, Stephen J.

2013-01-01

Participation in urban agriculture is growing throughout the United States; however, potential soil contaminants in urban environments present challenges. Individuals in direct contact with urban soil should be aware of urban soil quality and soil contamination issues to minimize environmental and human health risks. The study reported here…

Nematode grazing promotes bacterial community dynamics in soil at the aggregate level

PubMed Central

Jiang, Yuji; Liu, Manqiang; Zhang, Jiabao; Chen, Yan; Chen, Xiaoyun; Chen, Lijun; Li, Huixin; Zhang, Xue-Xian; Sun, Bo

2017-01-01

Nematode predation has important roles in determining bacterial community composition and dynamics, but the extent of the effects remains largely rudimentary, particularly in natural environment settings. Here, we investigated the complex microbial–microfaunal interactions in the rhizosphere of maize grown in red soils, which were derived from four long-term fertilization regimes. Root-free rhizosphere soil samples were separated into three aggregate fractions whereby the abundance and community composition were examined for nematode and total bacterial communities. A functional group of alkaline phosphomonoesterase (ALP) producing bacteria was included to test the hypothesis that nematode grazing may significantly affect specific bacteria-mediated ecological functions, that is, organic phosphate cycling in soil. Results of correlation analysis, structural equation modeling and interaction networks combined with laboratory microcosm experiments consistently indicated that bacterivorous nematodes enhanced bacterial diversity, and the abundance of bacterivores was positively correlated with bacterial biomass, including ALP-producing bacterial abundance. Significantly, such effects were more pronounced in large macroaggregates than in microaggregates. There was a positive correlation between the most dominant bacterivores Protorhabditis and the ALP-producing keystone 'species' Mesorhizobium. Taken together, these findings implicate important roles of nematodes in stimulating bacterial dynamics in a spatially dependent manner. PMID:28742069

Nematode grazing promotes bacterial community dynamics in soil at the aggregate level.

PubMed

Jiang, Yuji; Liu, Manqiang; Zhang, Jiabao; Chen, Yan; Chen, Xiaoyun; Chen, Lijun; Li, Huixin; Zhang, Xue-Xian; Sun, Bo

2017-12-01

Nematode predation has important roles in determining bacterial community composition and dynamics, but the extent of the effects remains largely rudimentary, particularly in natural environment settings. Here, we investigated the complex microbial-microfaunal interactions in the rhizosphere of maize grown in red soils, which were derived from four long-term fertilization regimes. Root-free rhizosphere soil samples were separated into three aggregate fractions whereby the abundance and community composition were examined for nematode and total bacterial communities. A functional group of alkaline phosphomonoesterase (ALP) producing bacteria was included to test the hypothesis that nematode grazing may significantly affect specific bacteria-mediated ecological functions, that is, organic phosphate cycling in soil. Results of correlation analysis, structural equation modeling and interaction networks combined with laboratory microcosm experiments consistently indicated that bacterivorous nematodes enhanced bacterial diversity, and the abundance of bacterivores was positively correlated with bacterial biomass, including ALP-producing bacterial abundance. Significantly, such effects were more pronounced in large macroaggregates than in microaggregates. There was a positive correlation between the most dominant bacterivores Protorhabditis and the ALP-producing keystone 'species' Mesorhizobium. Taken together, these findings implicate important roles of nematodes in stimulating bacterial dynamics in a spatially dependent manner.

Mineralogical, chemical, organic and microbial properties of subsurface soil cores from Mars Desert Research Station (Utah, USA): Phyllosilicate and sulfate analogues to Mars mission landing sites

NASA Astrophysics Data System (ADS)

Stoker, Carol R.; Clarke, Jonathan; Direito, Susana O. L.; Blake, David; Martin, Kevin R.; Zavaleta, Jhony; Foing, Bernard

2011-07-01

We collected and analysed soil cores from four geologic units surrounding Mars Desert Research Station (MDRS) Utah, USA, including Mancos Shale, Dakota Sandstone, Morrison formation (Brushy Basin member) and Summerville formation. The area is an important geochemical and morphological analogue to terrains on Mars. Soils were analysed for mineralogy by a Terra X-ray diffractometer (XRD), a field version of the CheMin instrument on the Mars Science Laboratory (MSL) mission (2012 landing). Soluble ion chemistry, total organic content and identity and distribution of microbial populations were also determined. The Terra data reveal that Mancos and Morrison soils are rich in phyllosilicates similar to those observed on Mars from orbital measurements (montmorillonite, nontronite and illite). Evaporite minerals observed include gypsum, thenardite, polyhalite and calcite. Soil chemical analysis shows sulfate the dominant anion in all soils and SO4>>CO3, as on Mars. The cation pattern Na>Ca>Mg is seen in all soils except for the Summerville where Ca>Na. In all soils, SO4 correlates with Na, suggesting sodium sulfates are the dominant phase. Oxidizable organics are low in all soils and range from a high of 0.7% in the Mancos samples to undetectable at a detection limit of 0.1% in the Morrison soils. Minerals rich in chromium and vanadium were identified in Morrison soils that result from diagenetic replacement of organic compounds. Depositional environment, geologic history and mineralogy all affect the ability to preserve and detect organic compounds. Subsurface biosphere populations were revealed to contain organisms from all three domains (Archaea, Bacteria and Eukarya) with cell density between 3.0×106 and 1.8×107 cells ml-1 at the deepest depth. These measurements are analogous to data that could be obtained on future robotic or human Mars missions and results are relevant to the MSL mission that will investigate phyllosilicates on Mars.

Agricultural legacies in forest environments: tree communities, soil properties, and light availability.

PubMed

Flinn, Kathryn M; Marks, P L

2007-03-01

Temperate deciduous forests across much of Europe and eastern North America reflect legacies of past land use, particularly in the diversity and composition of plant communities. Intense disturbances, such as clearing forests for agriculture, may cause persistent environmental changes that continue to shape vegetation patterns as landscapes recover. We assessed the long-term consequences of agriculture for environmental conditions in central New York forests, including tree community structure and composition, soil physical and chemical properties, and light availability. To isolate the effects of agriculture, we compared 20 adjacent pairs of forests that were never cleared for agriculture (primary forests) and forests that established 85-100 years ago on plowed fields (secondary forests). Tree communities in primary and secondary forests had similar stem density, though secondary forests had 14% greater basal area. Species composition differed dramatically between the two forest types, with primary forests dominated by Acer saccharum and Fagus grandifolia and secondary forests by Acer rubrum and Pinus strobus. Primary and secondary forests showed no consistent differences in soil physical properties or in the principal gradient of soil fertility associated with soil pH. Within stands, however, soil water content and pH were more variable in primary forests. Secondary forest soils had 15% less organic matter, 16% less total carbon, and 29% less extractable phosphorus in the top 10 cm than adjacent primary stands, though the ranges of the forest types mostly overlapped. Understory light availability in primary and secondary forests was similar. These results suggest that, within 100 years, post-agricultural stands have recovered conditions comparable to less disturbed forests in many attributes, including tree size and number, soil physical properties, soil chemical properties associated with pH, and understory light availability. The principal legacies of agriculture that remain in these forests are the reduced levels of soil organic matter, carbon, and phosphorus; the spatial homogenization of soil properties; and the altered species composition of the vegetation.

X-Ray Computed Tomography Reveals the Response of Root System Architecture to Soil Texture1[OPEN

PubMed Central

Rogers, Eric D.; Monaenkova, Daria; Mijar, Medhavinee; Goldman, Daniel I.

2016-01-01

Root system architecture (RSA) impacts plant fitness and crop yield by facilitating efficient nutrient and water uptake from the soil. A better understanding of the effects of soil on RSA could improve crop productivity by matching roots to their soil environment. We used x-ray computed tomography to perform a detailed three-dimensional quantification of changes in rice (Oryza sativa) RSA in response to the physical properties of a granular substrate. We characterized the RSA of eight rice cultivars in five different growth substrates and determined that RSA is the result of interactions between genotype and growth environment. We identified cultivar-specific changes in RSA in response to changing growth substrate texture. The cultivar Azucena exhibited low RSA plasticity in all growth substrates, whereas cultivar Bala root depth was a function of soil hardness. Our imaging techniques provide a framework to study RSA in different growth environments, the results of which can be used to improve root traits with agronomic potential. PMID:27208237

Production of PFOS from aerobic soil biotransformation of two perfluoroalkyl sulfonamide derivatives.

PubMed

Mejia Avendaño, Sandra; Liu, Jinxia

2015-01-01

The continuous production and use in certain parts of the world of perfluoroalkyl sulfonamide derivatives that can degrade to perfluorooctane sulfonic acid (PFOS) has called for better understanding of the environmental fate of these PFOS precursors. Aerobic soil biotransformation of N-ethyl perfluorooctane sulfonamide (EtFOSA, also known as Sulfluramid) was quantitatively investigated in semi-closed soil microcosms over 182 d for the first time. The apparent soil half-life of EtFOSA was 13.9±2.1 d and the yield to PFOS by the end of incubation was 4.0 mol%. A positive identification of a previously suspected degradation product, EtFOSA alcohol, provided strong evidence to determine degradation pathways. The lower mass balance in sterile soil than live soil suggested likely strong irreversible sorption of EtFOSA to the test soil. The aerobic soil biotransformation of a technical grade N-ethyl perfluorooctane sulfonamidoethanol (EtFOSE) was semi-quantitatively examined, and the degradation pathways largely followed those in activated sludge and marine sediments. Aside from PFOS, major degradation products included N-Ethyl perfluorooctane sulfonamidoacetic acid (EtFOSAA), perfluorooctane sulfonamide (FOSA) and perfluorooctane sulfonamide acetic acid (FOSAA). This study confirms that aerobic soil biotransformation of EtFOSE and EtFOSA contributes significantly to the PFOS observed in soil environment, as well as to several highly persistent sulfonamide derivatives frequently detected in biosolid-amended soils and landfill leachates. Copyright © 2014 Elsevier Ltd. All rights reserved.

[Effects of neighbor competition on growth, fine root morphology and distribution of Schima superba and Cunninghamia lanceolata in different nutrient environments].

PubMed

Yao, Jia Bao; Chu, Xiu Li; Zhou, Zhi Chun; Tong, Jian She; Wang, Hui; Yu, Jia Zhong

2017-05-18

Taking Schima superba and Cunninghamia lanceolata as test materials, a pot experiment was conducted to simulate the heterogeneous and homogeneous forest soil nutrient environments, and design three planting modes including single plant, two-strain pure plant and two-strain mixed ones to reason the promotion in mixed S. superba and C. lanceolata plantation and the competitive advantage of S. superba. Results showed that compared with the homogeneous nutrient environment, both S. superba and C. lanceolata had the higher seedling height and dry matter accumulation, when mixed in the heterogeneous nutrient environment, S. superba displayed the obviously competitive advantage, which related to its root plasticity. The fine root of S. superba mixed in each diameter class showed a lot of hyperplasia, and the root total length, surface area and volume of which were 80%-180% higher than that of C. lanceolata. S. superba took the advantage of the compensatory growth strategy of vertical direction in fine roots, namely, they still multiplied to gain greater competitive advantage in low nutrient patches, besides occupying eutrophic surface. The different soil colonization and niche differentiation in fine root of S. superba and C. lanceolata alleviated the strong competition for nutrients of the roots of the two species, and improved the mixed-plantation production. Pure plantation of S. superba harvested the lower yield, which due to the root self-recognition inhibited the growth of root system. Fine roots staggered and evenly distributed on the space might be a reason for stable structure of pure S. superba plantation. So, it was recommended that block surface layer soil preparation and fertilization are used to improve the soil nutrient distribution, and the mixed plantation is constructed to promote the growth of S. superba and C. lanceolata, at the same time, the stand density is regulated to promote tree growth for the pure artificial S. superba plantation which had already been built.

Multiparametric methane sensor for environmental monitoring

NASA Astrophysics Data System (ADS)

Borecki, M.; Duk, M.; Kociubiński, A.; Korwin-Pawlowski, M. L.

2016-12-01

Today, methane sensors find applications mostly in safety alarm installations, gas parameters detection and air pollution classification. Such sensors and sensors elements exists for industry and home use. Under development area of methane sensors application is dedicated to ground gases monitoring. Proper monitoring of soil gases requires reliable and maintenance-free semi-constant and longtime examination at relatively low cost of equipment. The sensors for soil monitoring have to work on soil probe. Therefore, sensor is exposed to environment conditions, as a wide range of temperatures and a full scale of humidity changes, as well as rain, snow and wind, that are not specified for classical methane sensors. Development of such sensor is presented in this paper. The presented sensor construction consists of five commercial non dispersive infra-red (NDIR) methane sensing units, a set of temperature and humidity sensing units, a gas chamber equipped with a micro-fan, automated gas valves and also a microcontroller that controls the measuring procedure. The electronics part of sensor was installed into customized 3D printed housing equipped with self-developed gas valves. The main development of proposed sensor is on the side of experimental evaluation of construction reliability and results of data processing included safety procedures and function for hardware error correction. Redundant methane sensor units are used providing measurement error correction as well as improved measurement accuracy. The humidity and temperature sensors are used for internal compensation of methane measurements as well as for cutting-off the sensor from the environment when the conditions exceed allowable parameters. Results obtained during environment sensing prove that the gas concentration readings are not sensitive to gas chamber vertical or horizontal position. It is important as vertical sensor installation on soil probe is simpler that horizontal one. Data acquired during six month of environment monitoring prove that error correction of methane sensing units was essential for maintenance free sensor operation, despite used safety procedures.

RUSLE2015, GIS-RWEQ and CENTURY: new modelling integration for soil loss and carbon fluxes at European scale

NASA Astrophysics Data System (ADS)

Panagos, Panos; Borrelli, Pasquale; Lugato, Emanuele

2016-04-01

Land degradation through erosion has been identified as major threat to European soils and agriculture. During the last years, the Directorates General for Agriculture and for Environment (plus EUROSTAT) require formal assessments and indicators on the state of soil erosion for the European Union. Moreover, the European Soil Data Centre (ESDAC) is the main data repository for soil threats at European scale. To meet these needs we have worked with recognized research institutes and scientists to develop a series of pan-EU modelling tools that estimate soil erosion by water and wind. Over the past three years, the European Commission Joint Research Centre has worked to develop a modified RUSLE modelling approach, named RUSLE2015 and the necessary input factors. These have all been peer reviewed and published as individual papers in different refereed journals. The published soil erodibility map for Europe has been modelled with the latest state of the art soil data (LUCAS) and a robust geo-statistical model (Science of Total Environment, 479-480: 189-200). Rainfall erosivity has been modelled after an extensive data collection of high temporal resolution rainfall data and the compilation of Rainfall Erosivity Database at European Scale (REDES) (Science of Total Environment, 511: 801-814). Cover-Management factor has been modelled taking into account crop composition, management practices (reduced tillage, plant residues, cover crops) and remote sensing data on vegetation density (Land Use policy, 48C: 38-50). Topography has been modelled with the recently published Digital Elevation Model at 25m resolution (Geosciences, 5: 117-126). Conservation and support practices have included the Good Agricultural Environmental Condition (GAEC database) and the 270,000 earth observations of LUCAS survey (Environmental Science & Policy 51: 23-34). The new assessment of soil erosion by water in Europe has been recently published (Environmental Science & Policy. 54: 438-447) and subsequently the core message focusing on soil erosion in agricultural lands was published in a recent correspondence in Nature (Nature, 526, 195). Additionally, the soil erosion potential for the European Union's forests was modelled using the high-resolution Global Forest Cover Loss map (2000-2012) and taking into consideration the lodging, forest cuts and forest fires (Ecological Indicators, 60:1208-1220). The first qualitative assessment of wind erosion at European scale has been done using the Index of Land Susceptibility to Wind Erosion (ILSWE) (Sustainability, 7(7): 8823-8836). The wind-erodible fraction of soil (EF) is one of the key parameters for estimating the susceptibility of soil to wind erosion (Geoderma, 232-234: 471-478). ILSWE was created by combining spatiotemporal variations of the most influential wind erosion factors such as climatic erosivity, soil erodibility, vegetation cover and landscape roughness) (Land Degradation & Development, 10.1002/ldr.2318). The quantitative assessment of wind erosion has been concluded recently using Revised Wind Erosion Equation (GIS-RWEQ). Modelling the lateral carbon fluxes due to soil erosion both at national scale (Land Use Policy, 50: 408-421) and at European scale (Global Change Biology, 10.1111/gcb.13198) is an important milestone in climate change perspective. We coupled soil erosion into a biogeochemistry model, running at 1 km2 resolution across the agricultural soils of the European Union (EU). In the future, the soil erosion (by water and wind) modelling activities will incorporate temporal variability, sediment transport and economic assessments of land degradation.

The Cannona Data Base: long-term field data for studies on soil management impact on runoff and erosion processes.

NASA Astrophysics Data System (ADS)

Biddoccu, Marcella; Ferraris, Stefano; Opsi, Francesca; Cavallo, Eugenio

2014-05-01

Long-term data have been collected by IMAMOTER-CNR from field-scale vineyard plots within the Tenuta Cannona Vine and Wine Experimental Centre of Regione Piemonte, which is located in a valuable vine production area in north-western Italy. Since 2000, runoff and soil erosion monitoring has been carried out under natural rainfall conditions on three parallel field plots (75 m long and 16,5 m wide, slope gradient about 15%) that are conducted with different inter-rows soil management techniques (conventional tillage, reduced tillage, controlled grass cover). Experimental plots are part of a 16-hectars experimental vineyard, managed in according to conventional farming for wine production. Recurrent surveys have been carried out in the runoff plots to investigate spatial and temporal variability of the soil bulk density, soil moisture and penetration resistance. The primary intent of the program was to evaluate the effects of agricultural management practices and tractor traffic on the hydrologic, soil erosion and soil compaction processes in vineyard. The Cannona Data Base (CDB) represents a data collection which is unique in Italy, showing the response of soil to rainfall in terms of runoff and soil erosion over more than a decade. It includes data for more than 200 runoff events and over 70 soil loss events; moreover, periodic measurements for soil physical characteristics are included for the three plots. The CDB can now be accessed via a website supported by the CNR, that is addressed to water and land management researchers and professionals. The CDB is currently used to calibrate a model for runoff and soil erosion prediction in vineyard environment. The CDB website includes a descriptive and informative section, which contains results of over than 10 years of experimental activity, reports and presentations, addressed to enhance the awareness of citizens and stakeholders about land degradation processes and about impacts of different soil management practices on water and soil conservation. The monitoring activities at the Cannona Experimental Site are currently carried out and implemented in order to improve the understanding of the soil management effects on soil hydrology, erosion and compaction in sloping vineyards. Land use and soil management strongly influence the hydrologic processes in the soil. In Italy vines are widely cultivated on hills and mountain slopes, within areas which are frequently affected by landslides. Such natural events are strictly related to hydrologic behavior of the soil, that drives the runoff formation on slopes and the consequent sediment delivery to water courses. Data from the CDB could be used in a multidisciplinary approach to investigate interactions among land use/ soil management and natural processes at different scales.

Leith Creek, Scotland County, North Carolina, Detailed Project Report. Revised.

DTIC Science & Technology

1977-07-01

34Effect of the Plan on Environ- " ment" included loss of veqetation, tei.porary erosion and siltation, and better drained soils for a very narrow strip...tangible damages. Tangible damages are those subject to monetary evaluation and include: physical damages or losses to property and improvements...emergency costs for flood damage prevention; and business, 0 financial, and wage losses in and adjacent to flood areas. Intangible damages are not

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.

Strategies Influencing Spatial Heterogeneity of Microbial Life in a Soil Lysimeter

NASA Astrophysics Data System (ADS)

Sengupta, A.; Neilson, J. W.; Meira, A.; Wang, Y.; Meza, M.; Chorover, J.; Maier, R. M.; Troch, P. A. A.

2016-12-01

Soil microorganisms are critical drivers of biogeochemical processes. These microbes, in conjunction with their physical and chemical environment, contribute to ecosystem functioning and services of the landscape, have a profound impact on soil formation, and are of particular importance in oligotrophic environments; ecosystems that are characterized by low biotic diversity due to extremely low nutrient levels. Here, we present a study of microbial heterogeneity in a soil lysimeter under incipient conditions. The key questions asked were: 1) what is the spatial heterogeneity of microbes over a new and evolving landscape with inherent oligotrophic conditions, and 2) can patterns in diversity translate to patterns in microbe-mediated weathering processes and soil formation? We hypothesized that stratification of environmental conditions, brought about by varying water potential, flow paths, and redox conditions, will drive the heterogeneity of microbial life in a sub-meter scale. A suite of traditional and current microbiological tools were employed to study community characteristics. These included isolation on R2A media, quantitative polymerase chain reactions targeted at 16S rRNA bacterial and archaeal genes, and 18S fungal genes, and iTAG phylogenetic gene amplification. Illumina Mi-Seq platform generated sequences were analyzed using various bioinformatics pipelines to identify community patterns, classify microbial metabolic functions, and identify variables affecting the community dynamics. Numerous phyla (Verrucomicrobia, Actinobacteria, Planctomycetes, Proteobacteria, and Euryarchaeota) were identified. The surface layer had distinctly different distribution of communities compared to the other layers. Metabolically heterogeneous groups were found with respect to depth, with metabolic functions further confirmed by predictive functional profiling of the microbial communities. Therefore, despite being highly oligotrophic, the system was rich in species and functional diversity. Alongside physical and chemical data, the patterns observed in spatial and functional heterogeneity of microbes under incipient conditions is unique, and allows us to predict strategies undertaken by these microbes to survive in, and influence their oligotrophic environments.

Trace elements in agroecosystems and impacts on the environment.

PubMed

He, Zhenli L; Yang, Xiaoe E; Stoffella, Peter J

2005-01-01

Trace elements mean elements present at low concentrations (mg kg-1 or less) in agroecosystems. Some trace elements, including copper (Cu), zinc (Zn), manganese (Mn), iron (Fe), molybdenum (Mo), and boron (B) are essential to plant growth and are called micronutrients. Except for B, these elements are also heavy metals, and are toxic to plants at high concentrations. Some trace elements, such as cobalt (Co) and selenium (Se), are not essential to plant growth but are required by animals and human beings. Other trace elements such as cadmium (Cd), lead (Pb), chromium (Cr), nickel (Ni), mercury (Hg), and arsenic (As) have toxic effects on living organisms and are often considered as contaminants. Trace elements in an agroecosystem are either inherited from soil parent materials or inputs through human activities. Soil contamination with heavy metals and toxic elements due to parent materials or point sources often occurs in a limited area and is easy to identify. Repeated use of metal-enriched chemicals, fertilizers, and organic amendments such as sewage sludge as well as wastewater may cause contamination at a large scale. A good example is the increased concentration of Cu and Zn in soils under long-term production of citrus and other fruit crops. Many chemical processes are involved in the transformation of trace elements in soils, but precipitation-dissolution, adsorption-desorption, and complexation are the most important processes controlling bioavailability and mobility of trace elements in soils. Both deficiency and toxicity of trace elements occur in agroecosystems. Application of trace elements in fertilizers is effective in correcting micronutrient deficiencies for crop production, whereas remediation of soils contaminated with metals is still costly and difficult although phytoremediation appears promising as a cost-effective approach. Soil microorganisms are the first living organisms subjected to the impacts of metal contamination. Being responsive and sensitive, changes in microbial biomass, activity, and community structure as a result of increased metal concentration in soil may be used as indicators of soil contamination or soil environmental quality. Future research needs to focus on the balance of trace elements in an agroecosystem, elaboration of soil chemical and biochemical parameters that can be used to diagnose soil contamination with or deficiency in trace elements, and quantification of trace metal transport from an agroecosystem to the environment.

Carbon sequestration potential of coastal wetland soils of Veracruz, Mexico

NASA Astrophysics Data System (ADS)

Fuentes-Romero, Elisabeth; García-Calderón, Norma Eugenia; Ikkonen, Elena; García-Varela, Kl

2014-05-01

Tropical coastal wetlands, including rainforests and mangrove ecosystems play an increasingly important ecological and economic role in the tropical coastal area of the State of Veracruz /Mexico. However, soil processes in these environments, especially C-turnover rates are largely unknown until today. Therefore, we investigated CO2 and CH4 emissions together with gains and losses of organic C in the soils of two different coastal ecosystems in the "Natural Protected Area Cienaga del Fuerte (NPACF)" near Tecolutla, in the State of Veracruz. The research areas were an artificially introduced grassland (IG) and a wetland rainforest (WRF). The gas emissions from the soil surfaces were measured by a static chamber array, the soil organic C was analysed in soil profiles distributed in the two areas, humic substances were characterized and C budget was calculated. The soils in both areas acted as carbon sinks, but the soils of the WRF sequestered more C than those of the IG, which showed a higher gas emission rate and produced more dissolved organic carbon. The gas emission measurements during the dry and the rainy seasons allowed for estimating the possible influence of global warming on gas fluxes from the soils of the two different ecological systems, which show in the WRF a quite complex spatial emission pattern during the rainy season in contrast to a more continuous emission pattern in the IG plots

Effects of tillage on the Fe oxides activation in soil

NASA Astrophysics Data System (ADS)

Chi, Guangyu; Chen, Xin; Shi, Yi; Wang, Jun; Zheng, Taihui

2009-07-01

Since mid-1950s, the wetland ecosystems in Sanjiang Plain of Northeast China have been experiencing greater changes in land use, which had negative effects on the soil environments. This study assessed the effects of soil tillage on the activation of soil Fe in the region. The test ecosystems included natural wetland, paddy field and upland field converted from wetland. Soil samples at the depths of 0-10 cm, 10-20 cm, 20-30 cm, 30-40 cm, 40-60 cm, 60-90 cm and 90-120 cm were collected from each of the ecosystems for the analysis of vertical distribution of soil pH, organic carbon, chelate Fe oxides and Fe(II). The results showed that the conversion of wetland into paddy field and upland field induced a decrease of organic carbon content in 0-10 cm soil layer by 61.8% (P <0.05) and 70.0% (P < 0.05), respectively. The correlations among iron forms and soil organic carbon showed that chelate Fe oxides and Fe(II) was correlated positively with soil organic carbon and chelate ratio had a more positive relationship with organic carbon than chelate Fe oxides and Fe(II). The results of chelate Fe oxides, Fe(II) and chelate ratio of Fe suggested that reclamation could prevent the Fe activation and organic matter is credited for having an important influence on the process of Fe activation.

Aliphatic hydrocarbons recovered in vegetables from soils based on their in-situ distribution in various soil humus fractions using a successive extraction method.

PubMed

Zhang, Juan; Fan, Shu-Kai; Zhang, Ming-Hua; Grieneisen, Michael L; Zhang, Jian-Feng

2018-03-15

Aliphatic hydrocarbons (AHs) are major petroleum contaminants in the environment. In this study, the AHs bound to various soil endogenetic humus fractions were separated through successive extraction. Most of the AHs (46.1%) in soils were adsorbed onto/into humic acids (HA) and a small quantity of AHs (9.6%) were organic solvent extractable. AHs in B. chinensis were also analyzed since their potential risks to the residents through ingestion. AHs from C 21 to C 34 , so called high molecular weight AHs (HMWAHs), were dominant AHs in B. chinensis (85.5%) and soils (70.4%), followed by AHs from C 16 to C 21, whose mobility can be enhanced via binding to fulvic acids and then can be taken up by plant root lipids (soil-plant pathway). HMWAHs were mainly HA-bound and then were detained in the top soil layers. HMWAHs associated with fine topsoil particles could be transported to B. chinensis via the soil-air-plant pathway, including resuspension and aboveground plant cuticle capture. Results from Principal Component Analysis combined with Regression Analysis supported this assumption due to the positive correlations between HMWAHs concentration in B. chinensis and fine particle contents in soils. This work presents the distributions of petroleum contaminants that result from previously described behavior mechanisms. Copyright © 2017 Elsevier B.V. All rights reserved.

Impact of industrial effluent on growth and yield of rice (Oryza sativa L.) in silty clay loam soil.

PubMed

Anwar Hossain, Mohammad; Rahman, Golum Kibria Muhammad Mustafizur; Rahman, Mohammad Mizanur; Molla, Abul Hossain; Mostafizur Rahman, Mohammad; Khabir Uddin, Mohammad

2015-04-01

Degradation of soil and water from discharge of untreated industrial effluent is alarming in Bangladesh. Therefore, buildup of heavy metals in soil from contaminated effluent, their entry into the food chain and effects on rice yield were quantified in a pot experiment. The treatments were comprised of 0, 25%, 50%, 75% and 100% industrial effluents applied as irrigation water. Effluents, initial soil, different parts of rice plants and post-harvest pot soil were analyzed for various elements, including heavy metals. Application of elevated levels of effluent contributed to increased heavy metals in pot soils and rice roots due to translocation effects, which were transferred to rice straw and grain. The results indicated that heavy metal toxicity may develop in soil because of contaminated effluent application. Heavy metals are not biodegradable, rather they accumulate in soils, and transfer of these metals from effluent to soil and plant cells was found to reduce the growth and development of rice plants and thereby contributed to lower yield. Moreover, a higher concentration of effluent caused heavy metal toxicity as well as reduction of growth and yield of rice, and in the long run a more aggravated situation may threaten human lives, which emphasizes the obligatory adoption of effluent treatment before its release to the environment, and regular monitoring by government agencies needs to be ensured. Copyright © 2015. Published by Elsevier B.V.

Field classes: key to involve and attract students to soils

NASA Astrophysics Data System (ADS)

Muggler, Cristine Carole; Cardoso, Irene Maria; da Silva Lopes, Angelica

2015-04-01

Soil genesis is a subject taught to students of Agrarian Sciences and Geography at the Federal University of Viçosa in Minas Gerais, Brazil. Each semester 200 to 250 students inscribe for it. It is organized as the first 60 hours course on soils for 1st and 2nd year's students. The course has a distinct pedagogical approach, which is based on Paulo Freire's education principles, known as socio constructivism. In such approach, learning environments and materials are prepared to stimulate dialogues and exchange of knowledge between students themselves, strengthening that their role is crucial to their own learning. During the course, students have different types of practical classes: indoors, in a class room or at the Earth Sciences museum and outdoors, in the field. In the class room they have the opportunity to handle materials -minerals, rocks, soils and maps-, follow demonstrations and perform small experiments. The classes given in the museum intend a broadening of the subjects approached in theoretical and practical classes. In the field classes the students are organized in small groups with the task to investigate soil formation by observation and description of geology, landscape, land use, soil expositions and some of the soil properties. Attracting students to soils involves looking at meanings and perceptions related to soils they bring with themselves and follow this up to sensitize and create awareness about their importance. With this aim, it is also included, as part of the evaluation, a final voluntary presentation that many of the students do. The presentation can be a song, a poem, a sketch or whatever they propose and create. Many of the presentations bring topics related to the new perception about soils they get during the semester and to ideas or questions raised in the field classes. A survey with the students showed that field classes are by far the preferred classes and they are considered more dynamic. Since students have less and less contact with soils and rural livelihoods before they enter the university, field classes are best to make the connections between their (mostly urban) life and the soils. They also play an important role in developing an integrated observation and understanding of the environment and land use.

Uptake and metabolism of 10:2 fluorotelomer alcohol in soil-earthworm (Eisenia fetida) and soil-wheat (Triticum aestivum L.) systems.

PubMed

Zhao, Shuyan; Zhu, Lingyan

2017-01-01

The behavior of 10:2 fluorotelomer alcohol (10:2 FTOH) in the systems of soil-earthworm (Eisenia fetida), soil-wheat (Triticum aestivum L.) and soil-earthworm-wheat, including degradation in soil, uptake and metabolism in wheat and earthworms were investigated. Several perfluorocarboxylic acids (PFCAs) as degradation products of 10:2 FTOH were identified in the soil, plant and earthworms. 10:2 FTOH could be biodegraded to perfluorooctanoate (PFOA), perfluorononanate (PFNA) and perfluorodecanoate (PFDA) in soil in the absence or presence of wheat/earthworms, and PFDA was the predominant metabolite. Accumulation of initial 10:2 FTOH and its metabolites were observed in the wheat and earthworms, suggesting that 10:2 FTOH could be bioaccumulated in wheat and earthworms and biotransformed to the highly stable PFCAs. Perfluoropentanoic acid (PFPeA), perfluorohexanoic (PFHxA) and PFDA were detected in wheat root, while PFDA and perfluoroundecanoic acid (PFUnDA) were detected in shoot. PFNA and PFDA were determined in earthworms and the concentration of PFDA was much higher. The presence of earthworms and/or plant stimulated the microbial degradation of 10:2 FTOH in soil. The results supplied important evidence that degradation of 10:2 FTOH was an important potential source of PFCAs in the environment and in biota. Copyright © 2016 Elsevier Ltd. All rights reserved.

The impact of unconfined mine tailings in residential areas from a mining town in a semi-arid environment: Nacozari, Sonora, Mexico

PubMed Central

Meza-Figueroa, Diana; Maier, Raina M.; de la O-Villanueva, Margarita; Gómez-Alvarez, Agustín; Moreno-Zazueta, Alan; Rivera, Jacinto; Campillo, Alberto; Grandlic, Christopher; Anaya, Ricardo; Palafox-Reyes, Juan

2009-01-01

Past mining activities in northern Mexico left a legacy of delerict landscapes devoid of vegetation and seasonal formation of salt efflorescence. Metal content was measured in mine tailings, efflorescent salts, soils, road dust and residential soils to investigate contamination. Climatic effects such as heavy wind and rainfall events can have great impact on the dispersion of metals in semi-arid areas, since soils are typically sparsely vegetated. Geochemical analysis of this site revealed that even though total metal content in mine tailings was relatively low (e.g. Cu = 1000 mg kg-1), metals including Mn, Ba, Zn, and Cu were all found at significantly higher levels in efflorescence salts formed by evaporation on the tailings impoundment surface following the rainy season (e.g. Cu=68000 mg kg-1). Such efflorescent fine-grained salts are susceptible to wind erosion resulting in increased metal spread to nearby residential soils. Our results highlight the importance of seasonally dependent salt-formation and wind erosion in determining risk levels associated with potential inhalation or ingestion of airborne particulates originating from contaminated sites such as tailings impoundments. In low metal-content mine tailings located in arid and semi-arid environments, efflorescence salts could represent a human health risk and a challenge for plant establishment in mine tailings. PMID:19500816

The impact of unconfined mine tailings in residential areas from a mining town in a semi-arid environment: Nacozari, Sonora, Mexico.

PubMed

Meza-Figueroa, Diana; Maier, Raina M; de la O-Villanueva, Margarita; Gómez-Alvarez, Agustín; Moreno-Zazueta, Alan; Rivera, Jacinto; Campillo, Alberto; Grandlic, Christopher J; Anaya, Ricardo; Palafox-Reyes, Juan

2009-09-01

Past mining activities in northern Mexico left a legacy of delerict landscapes devoid of vegetation and seasonal formation of salt efflorescence. Metal content was measured in mine tailings, efflorescent salts, soils, road dust, and residential soils to investigate contamination. Climatic effects such as heavy wind and rainfall events can have great impact on the dispersion of metals in semi-arid areas, since soils are typically sparsely vegetated. Geochemical analysis of this site revealed that even though total metal content in mine tailings was relatively low (e.g. Cu= 1000 mg kg(-1)), metals including Mn, Ba, Zn, and Cu were all found at significantly higher levels in efflorescence salts formed by evaporation on the tailings impoundment surface following the rainy season (e.g. Cu= 68,000 mg kg(-1)). Such efflorescent fine-grained salts are susceptible to wind erosion resulting in increased metal spread to nearby residential soils. Our results highlight the importance of seasonally dependent salt-formation and wind erosion in determining risk levels associated with potential inhalation or ingestion of airborne particulates originating from contaminated sites such as tailings impoundments. In low metal-content mine tailings located in arid and semi-arid environments, efflorescence salts could represent a human health risk and a challenge for plant establishment in mine tailings.

Sorption and degradation of pharmaceuticals and personal care products (PPCPs) in soils.

PubMed

Yu, Yong; Liu, Yin; Wu, Laosheng

2013-06-01

Pharmaceuticals and personal care products (PPCPs) are one class of the most urgent emerging contaminants, which have drawn much public and scientific concern due to widespread contamination in aquatic environment. Most studies on the environmental fate and behavior of PPCPs have focused on nonsteroidal anti-inflammatory drugs. Some other compounds with high concentrations were less mentioned. In this study, sorption and degradation of five selected PPCPs, including bisphenol A (BPA), carbamazepine (CBZ), gemfibrozil (GFB), octylphenol (OP), and triclosan (TCS) have been investigated using three different soils. Sorption isotherms of all tested PPCPs in soils were well described by Freundlich equation. TCS and OP showed moderate to strong sorption, while the sorption of GFB and CBZ in soils was negligible. Degradation of PPCPs in three soils was generally fitted first-order exponential decay model, with half-lives (t 1/2) varying from 9.8 to 39.1 days. Sterilization could prolong the t 1/2 of PPCPs in soil, indicating that microbial activity played an important role in the degradation of these chemicals in soils. Degradation of PPCPs in soils was also influenced by the soil organic carbon (f oc) contents. Results from our data show that sorption to the soils varied among the different PPCPs, and their sorption affinity on soil followed the order of TCS > OP > BPA > GFB > CBZ. The degradation of the selected PPCPs in soil was influenced by the microbial activity and soil type. The poor sorption and relative persistence of CBZ suggest that it may pose a high leaching risk for groundwater contamination when recycled for irrigation.

Review and Outlook for Soil and Tillage Research.

USDA-ARS?s Scientific Manuscript database

The journal, Soil and Tillage Research, is concerned with the changes in physical, chemical and biological properties and processes of the soil environment brought about by soil tillage and field traffic, their effects on both below- and above-ground environmental quality, crop establishment, root d...

NASA Giovanni: A Tool for Visualizing, Analyzing, and Inter-Comparing Soil Moisture Data

NASA Technical Reports Server (NTRS)

Teng, William; Rui, Hualan; Vollmer, Bruce; deJeu, Richard; Fang, Fan; Lei, Guang-Dih

2012-01-01

There are many existing satellite soil moisture algorithms and their derived data products, but there is no simple way for a user to inter-compare the products or analyze them together with other related data (e.g., precipitation). An environment that facilitates such inter-comparison and analysis would be useful for validation of satellite soil moisture retrievals against in situ data and for determining the relationships between different soil moisture products. The latter relationships are particularly important for applications users, for whom the continuity of soil moisture data, from whatever source, is critical. A recent example was provided by the sudden demise of EOS Aqua AMSR-E and the end of its soil moisture data production, as well as the end of other soil moisture products that had used the AMSR-E brightness temperature data. The purpose of the current effort is to create an environment, as part of the NASA Giovanni family of portals, that facilitates inter-comparisons of soil moisture algorithms and their derived data products.

Radionuclide Concentrations in Terrestrial Vegetation and Soil Samples On and Around the Hanford Site, 1971 Through 2008

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

Simmons, Mary Ann; Poston, Ted M.; Fritz, Brad G.

2011-07-29

Environmental monitoring is conducted on the U.S. Department of Energy (DOE) Hanford Site to comply with DOE Orders and federal and state regulations. Major objectives of the monitoring are to characterize contaminant levels in the environment and to determine site contributions to the contaminant inventory. This report focuses on surface soil and perennial vegetation samples collected between 1971 and 2008 as part of the Pacific Northwest National Laboratory Surface Environmental Surveillance Project performed under contract to DOE. Areas sampled under this program are located on the Hanford Site but outside facility boundaries and on public lands surrounding the Hanford Site.more » Additional samples were collected during the past 8 years under DOE projects that evaluated parcels of land for radiological release. These data were included because the same sampling methodology and analytical laboratory were used for the projects. The spatial and temporal trends of six radionuclides collected over a 38-year period were evaluated. The radionuclides----cobalt-60, cesium-137, strontium-90, plutonium-238, plutonium-239/240, and uranium (reported either as uranium-238 or total uranium)----were selected because they persist in the environment and are still being monitored routinely and reported in Hanford Site environmental reports. All these radionuclides were associated with plutonium production and waste management of activities occurring on the site. Other sources include fallout from atmospheric testing of nuclear weapons, which ended in 1980, and the Chernobyl explosion in 1986. Uranium is also a natural component of the soil. This assessment of soil and vegetation data provides important information on the distribution of radionuclides in areas adjacent to industrial areas, established perimeter locations and buffer areas, and more offsite nearby and distant locations. The concentrations reflect a tendency for detection of some radionuclides close to where they were utilized onsite, but as one moves to unindustrialized areas on the site, surrounding buffer areas and perimeter location into the more distant sites, concentrations of these radionuclides approach background and cannot be distinguished from fallout activity. More importantly, concentrations in soil and vegetation samples did not exceed environmental benchmark concentrations, and associated exposure to human and ecological receptors were well below levels that are demonstratively hazardous to human health and the environment.« less

Spatial Variation of Surface Soil Available Phosphorous and Its Relation with Environmental Factors in the Chaohu Lake Watershed

PubMed Central

Gao, Yongnian; Gao, Junfeng; Chen, Jiongfeng

2011-01-01

The study presented in this paper attempts to evaluate the spatial pattern of soil available phosphorus, as well as the relation between soil available phosphorus and environment factors including elevation, slope, precipitation, percentage of cultivated land, percentage of forest land, percentage of construction land and NDVI using statistical methods and GIS spatial analysis techniques. The results showed that the Spline Tension method performed the best in the prediction of soil available phosphorus in the Chaohu Lake watershed. The spatial variation of surface soil available phosphorus was high in Chaohu Lake watershed and the upstream regions around Chaohu Lake, including the west of Chaohu lake (e.g., southwest of Feixi county, east of Shucheng county and north of Lujiang county) and to the north of Chaohu Lake (e.g., south of Hefei city, south of Feidong county, southwest of Juchao district), had the highest soil available phosphorus content. The mean and standard deviation of soil available phosphorus content gradually decreased as the elevation or slope increased. The cultivated land comprised 60.11% of the watershed and of that land 65.63% belonged to the medium to very high SAP level classes, and it played a major role in SAP availability within the watershed and a potential source of phosphorus to Chaohu Lake resulting in eutrophication. Among the land use types, paddy fields have some of the highest maximum values and variation of coefficients. Subwatershed scale soil available phosphorus was significantly affected by elevation, slope, precipitation, percentage of cultivated land and percentage of forest land and was decided by not only these environmental factors but also some other factors such as artificial phosphorus fertilizer application. PMID:21909308

Lead distribution and its potential risk to the environment: lesson learned from environmental monitoring of abandon mine.

PubMed

Nobuntou, Wanida; Parkpian, Preeda; Oanh, Nguyen Thi Kim; Noomhorm, Athapol; Delaune, R D; Jugsujinda, Aroon

2010-11-01

There are many abandon and existing mines (tin, lead and zinc) in the mountainous areas of Thailand. Toxic elements including heavy metals such as lead (Pb), cadmium (Cd) and arsenic (As) have been released and transported from the mining sites to the adjacent landscape. In Thong Pha Phum District, Kanchanaburi Province, Thailand Pb contamination in the vicinity of the mine has occurred which could lead to potential health problems in downstream communities. To better understand current status of Pb contamination and accumulation in the surrounding environment and potential health impact, surface sediment, soil and plant samples were collected seasonally from representative monitoring sites along the aquatic track or flow regime. Potential health risk was determined using hazard quotient (HQ) as an index for local inhabitants who consume rice. Environmental monitoring illustrated that Pb concentrations in the surface sediment was as high as 869.4 mg kg(-1) dry weight and varied differently among stations sampled. Lead content in agricultural soil ranged between 137.8 to 613.5 mg kg(-1) dry weight and was inversely proportion to the distance from the point source. Moreover Pb was transported from the point source to down hill areas. At the highly polluted monitoring stations (S1, S2, and S3), concentrations of Pb exceeded the maximum allowable concentration for Pb in agricultural soil (300 mg kg(-1)) by 1.7-2 times. The Pb in soil was primarily associated with Fe/Mn oxides bound fraction (46-56%) followed by the organic bound fraction (25-30%). Lead uptake by plant varied and was species dependent. However root and tuber crops like cassava (19.92 mg Pb kg(-1) dry weight) and curcumin (3.25 mg Pb kg(-1) dry weight) could have removed Pb from the soil which suggest growing root crops in Pb contaminated soils should be avoided. However Cd, a co-contaminant at one of monitored stations (S4) yielded rice grain with Cd exceeding the maximum allowable concentration suggesting some potential health risk (HQ = 5.34) if people consume rice grown at this station. Overall result shows a low risk associated with Pb release into the environment.

Environmental Dissemination of Multidrug Methicillin-Resistant Staphylococcus sciuri After Application of Manure from Commercial Swine Production Systems.

PubMed

Kumar, Deepak; Pornsukarom, Suchawan; Sivaraman, G K; Thakur, Siddhartha

2018-04-01

The deposition of manure originating from food animal farms in the environment can lead to the dissemination of antimicrobial-resistant (AMR) bacterial foodborne pathogens, thereby potentially impacting human health. The objective of our study was to determine the dissemination of multidrug methicillin-resistant Staphylococcus sciuri (MDR-MRSS) in the environment after land application of manure on commercial swine farms. A total of 400 environmental samples (40 manure and 360 soil) were collected after repeated sampling from four commercial swine farms located in North Carolina (n = 1) and Iowa (n = 3) in the United States. At each farm, we collected 10 manure and 40 soil samples (20 samples before and after 2 h of manure application) from four plots (five soil samples/plot) on day 0. Subsequently, 20 soil samples were collected on day 7, 14, and 21 from the same plots. A total of 67 (16.75%) MRSS were isolated from the 400 samples. The prevalence in soil and manure was 13.33% (48/360) and 47.5% (19/40), respectively. Prevalence was highest in the soil samples collected after 2 h of manure application on day 0 and decreased subsequently on 7, 14, and 21 days. Antimicrobial susceptibility testing was done against a panel of 12 antibiotics. A majority of S. sciuri isolates exhibited resistance against ampicillin (AMP; 95.5%), penicillin (PEN; 95.5%), clindamycin (CLI; 95.5%), cefoxitin (FOX; 92.5%), ceftiofur (XNL; 92.5%), tetracycline (TET; 86.56%), and erythromycin (ERY; 50.74%). The MDR pattern AMP FOX CLI PEN TET XNL (n = 24; 35.8%) was the most commonly observed. We detected multiple AMR genes, including mecA, aac(6'), Ie-aph(2″)Ia, tetM, tetK, mphC, ermA, ermB, and ermC. Pulsed-field gel electrophoresis clustered isolates from different sample collection days from the same farm into one group. Overall, our study identifies swine manure as an important reservoir of MDR-MRSS and highlights its dissemination in the environment upon spreading of manure.

Development and Testing of an ISRU Soil Mechanics Vacuum Test Facility

NASA Technical Reports Server (NTRS)

Kleinhenz, Julie E.; Wilkinson, R. Allen

2014-01-01

For extraterrestrial missions, earth based testing in relevant environments is key to successful hardware development. This is true for both early component level development and system level integration. For In-Situ Resource Utilization (ISRU) on the moon, hardware must interface with the surface material, or regolith, in a vacuum environment. A relevant test environment will therefore involve a vacuum chamber with a controlled, properly conditioned bed of lunar regolith simulant. However, in earth-based granular media, such as lunar regolith simulant, gases trapped within the material pore structures and water adsorbed to all particle surfaces will release when exposed to vacuum. Early vacuum testing has shown that this gas release can occur violently, which loosens and weakens the simulant, altering the consolidation state. A mid-size chamber (3.66 m tall, 1.5 m inner diameter) at the NASA Glenn Research Center has been modified to create a soil mechanics test facility. A 0.64 m deep by 0.914 m square metric ton bed of lunar simulant was placed under vacuum using a variety of pumping techniques. Both GRC-3 and LHT-3M simulant types were used. Data obtained from an electric cone penetrometer can be used to determine strength properties at vacuum including: cohesion, friction angle, bulk density and shear modulus. Simulant disruptions, caused by off-gassing, affected the strength properties, but could be mitigated by reducing pump rate. No disruptions were observed at pressures below 2.5 Torr, regardless of the pump rate. The slow off-gassing of the soil at low pressure lead to long test times; a full week to reach 10(exp -5) Torr. Robotic soil manipulation would enable multiple ISRU hardware test within the same vacuum cycle. The feasibility of a robotically controlled auger and tamper was explored at vacuum conditions.

Soil coring at multiple field environments can directly quantify variation in deep root traits to select wheat genotypes for breeding.

PubMed

Wasson, A P; Rebetzke, G J; Kirkegaard, J A; Christopher, J; Richards, R A; Watt, M

2014-11-01

We aim to incorporate deep root traits into future wheat varieties to increase access to stored soil water during grain development, which is twice as valuable for yield as water captured at younger stages. Most root phenotyping efforts have been indirect studies in the laboratory, at young plant stages, or using indirect shoot measures. Here, soil coring to 2 m depth was used across three field environments to directly phenotype deep root traits on grain development (depth, descent rate, density, length, and distribution). Shoot phenotypes at coring included canopy temperature depression, chlorophyll reflectance, and green leaf scoring, with developmental stage, biomass, and yield. Current varieties, and genotypes with breeding histories and plant architectures expected to promote deep roots, were used to maximize identification of variation due to genetics. Variation was observed for deep root traits (e.g. 111.4-178.5cm (60%) for depth; 0.09-0.22cm/°C day (144%) for descent rate) using soil coring in the field environments. There was significant variation for root traits between sites, and variation in the relative performance of genotypes between sites. However, genotypes were identified that performed consistently well or poorly at both sites. Furthermore, high-performing genotypes were statistically superior in root traits than low-performing genotypes or commercial varieties. There was a weak but significant negative correlation between green leaf score (-0.5), CTD (0.45), and rooting depth and a positive correlation for chlorophyll reflectance (0.32). Shoot phenotypes did not predict other root traits. This study suggests that field coring can directly identify variation in deep root traits to speed up selection of genotypes for breeding programmes. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Disentangling above- and below-ground facilitation drivers in arid environments: the role of soil microorganisms, soil properties and microhabitat.

PubMed

Lozano, Yudi M; Armas, Cristina; Hortal, Sara; Casanoves, Fernando; Pugnaire, Francisco I

2017-12-01

Nurse plants promote establishment of other plant species by buffering climate extremes and improving soil properties. Soil biota plays an important role, but an analysis to disentangle the effects of soil microorganisms, soil properties and microclimate on facilitation is lacking. In three microhabitats (gaps, small and large Retama shrubs), we placed six microcosms with sterilized soil, two per soil origin (i.e. from each microhabitat). One in every pair received an alive, and the other a sterile, inoculum from its own soil. Seeds of annual plants were sown into the microcosms. Germination, survival and biomass were monitored. Soil bacterial communities were characterized by pyrosequencing. Germination in living Retama inoculum was nearly double that of germination in sterile inoculum. Germination was greater under Retama canopies than in gaps. Biomass was up to three times higher in nurse than in gap soils. Soil microorganisms, soil properties and microclimate showed a range of positive to negative effects on understory plants depending on species identity and life stage. Nurse soil microorganisms promoted germination, but the effect was smaller than the positive effects of soil properties and microclimate under nurses. Nurse below-ground environment (soil properties and microorganisms) promoted plant growth and survival more than nurse microhabitat. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

Influences of solution chemical conditions on mobilization of TNT from contaminated soil

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

Dante, D.A.; Tiller, C.L.; Pennell, K.D.

1996-12-31

Residual explosives and their byproducts are common contaminants at several US military installations. One of the major explosive contaminants is 2,4,6-Trinitrotoluene (TNT) (a hydrophobic organic compound). Contamination from TNT has resulted from manufacturing and handling processes which occurred at military installations, especially Army Ammunition Plants (AAP), over many decades until environmental regulations were implemented. TNT causes adverse effects to the environment, including growth inhibition to plants, toxicity to aquatic life, and possible mutagenicity, and also is toxic to humans. As a result of the effects of TNT on the environment and current environmental regulations, substantial research effort has been focusedmore » on determining the fate of TNT in natural systems and the development of remediation processes. Many potential remediation processes, such as those involving plants or microorganisms, are in part limited by the transfer of TNT from solid phases (e.g., sorbed to soil or present as TNT granules) to the aqueous phase. The purpose of this research is to assess the release of TNT from a soil phase to a mobile aqueous phase under varying solution chemical conditions. In particular, influences of pH, aquatic natural organic matter, and surfactants are investigated.« less

Health and safety plan for the removal action at the former YS-860 Firing Ranges, Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

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

NONE

1998-04-28

This health and safety plan sets forth the requirements and procedures to protect the personnel involved in the Lead Source Removal Project at the Former YS-86O Firing Ranges. This project will be conducted in a manner that ensures the protection of the safety and health of workers, the public, and the environment. The purpose of this removal action is to address lead contaminated soil and reduce a potential risk to human health and the environment. This site is an operable unit within the Upper East Fork Poplar Creek watershed. The removal action will contribute to early source actions within themore » watershed. The project will accomplish this through the removal of lead-contaminated soil in the target areas of the two small arms firing ranges. This plan covers the removal actions at the Former YS-86O Firing Ranges. These actions involve the excavation of lead-contaminated soils, the removal of the concrete trench and macadam (asphalt) paths, verification/confirmation sampling, grading and revegetation. The primary hazards include temperature extremes, equipment operation, noise, potential lead exposure, uneven and slippery working surfaces, and insects.« less

Quadrant III RFI draft report: Volume 1

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

Not Available

1992-12-01

The purpose of the RCRA Facility Investigation (RFI) at The Portsmouth Gaseous Diffusion Plant (PORTS) is to acquire, analyze and interpret data that will: characterize the environmental setting, including ground water, surface water and sediment, soil and air; define and characterize sources of contamination; characterize the vertical and horizontal extent and degree of contamination of the environment; assess the risk to human health and the environment resulting from possible exposure to contaminants; and support the Corrective Measures Study (CMS), which will follow the RFI, if required. A total of 18 Solid Waste Management Units (SWMU's) were investigated. All surficial soilmore » samples (0--2 ft), sediment samples and surface-water samples proposed in the approved Quadrant III RFI Work Plan were collected as specified in the approved work plan and RFI Sampling Plan. All soil, sediment and surface-water samples were analyzed for parameters specified from the Target Compound List and Target Analyte List (TCL/TAL) as listed in the US EPA Statement of Work for Inorganic (7/88a) and Organic (2/88b) analyses for Soil and Sediment, and analyses for fluoride, Freon-113 and radiological parameters (total uranium, gross alpha, gross beta and technetium).« less

Quadrant III RFI draft report: Volume 1

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

Not Available

1992-12-01

The purpose of the RCRA Facility Investigation (RFI) at The Portsmouth Gaseous Diffusion Plant (PORTS) is to acquire, analyze and interpret data that will: characterize the environmental setting, including ground water, surface water and sediment, soil and air; define and characterize sources of contamination; characterize the vertical and horizontal extent and degree of contamination of the environment; assess the risk to human health and the environment resulting from possible exposure to contaminants; and support the Corrective Measures Study (CMS), which will follow the RFI, if required. A total of 18 Solid Waste Management Units (SWMU`s) were investigated. All surficial soilmore » samples (0--2 ft), sediment samples and surface-water samples proposed in the approved Quadrant III RFI Work Plan were collected as specified in the approved work plan and RFI Sampling Plan. All soil, sediment and surface-water samples were analyzed for parameters specified from the Target Compound List and Target Analyte List (TCL/TAL) as listed in the US EPA Statement of Work for Inorganic (7/88a) and Organic (2/88b) analyses for Soil and Sediment, and analyses for fluoride, Freon-113 and radiological parameters (total uranium, gross alpha, gross beta and technetium).« less

Environment sensing in spring-dispersed seeds of a winter annual Arabidopsis influences the regulation of dormancy to align germination potential with seasonal changes

PubMed Central

Footitt, Steven; Clay, Heather A; Dent, Katherine; Finch-Savage, William E

2014-01-01

Seed dormancy cycling plays a crucial role in the lifecycle timing of many plants. Little is known of how the seeds respond to the soil seed bank environment following dispersal in spring into the short-term seed bank before seedling emergence in autumn.Seeds of the winter annual Arabidopsis ecotype Cvi were buried in field soils in spring and recovered monthly until autumn and their molecular eco-physiological responses were recorded.DOG1 expression is initially low and then increases as dormancy increases. MFT expression is negatively correlated with germination potential. Abscisic acid (ABA) and gibberellin (GA) signalling responds rapidly following burial and adjusts to the seasonal change in soil temperature. Collectively these changes align germination potential with the optimum climate space for seedling emergence.Seeds naturally dispersed to the soil in spring enter a shallow dormancy cycle dominated by spatial sensing that adjusts germination potential to the maximum when soil environment is most favourable for germination and seedling emergence upon soil disturbance. This behaviour differs subtly from that of seeds overwintered in the soil seed bank to spread the period of potential germination in the seed population (existing seed bank and newly dispersed). As soil temperature declines in autumn, deep dormancy is re-imposed as seeds become part of the persistent seed bank. PMID:24444091

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...

Examining Low-Impact Recreation Behavior--The Effects of Values, Attitudes and Timing of Educational Messaging

ERIC Educational Resources Information Center

Guo, Tian

2016-01-01

A considerable amount of previous research has documented the adverse impacts of recreation activities on the natural environment. These impacts, which include soil compaction and erosion, loss of vegetation and degraded wildlife habitat, can result in the severe degradation of ecosystem function and the quality of recreation experiences if left…

Modeling of Hydraulic Fracturing on the Basis of the Particle Method

NASA Astrophysics Data System (ADS)

Berezhnoi, D. V.; Gabsalikova, N. F.; Izotov, V. G.; Miheev, V. V.

2018-01-01

A technique of calculating the deformation of the soil environment when it interacts with a liquid on the basis of the particle method a is realized. To describe the behavior of the solid and liquid phases of the soil, a classical two-parameter Lennard-Jones interaction potential and its modified version proposed by the authors were chosen. The model problem of deformation and partial destruction of a soil massif under strong pressure from the liquid pumped into it is solved. Analysis of the results shows that the use of the modified Lennard-Jones potential for describing the solid phase of the soil environment makes it possible to describe the process of formation of cracks in the soil during hydraulic fracturing of the formation.

Infiltration performance of engineered surfaces commonly used for distributed stormwater management

NASA Astrophysics Data System (ADS)

Valinski, Nicholas A.

Engineered porous media are commonly used in low impact development (LID) structures to mitigate excess stormwater in urban environments. Differences in infiltrability of these LID systems arise from the wide variety of materials used to create porous surfaces and subsequent maintenance, debris loading, and physical damage. In this study, infiltration capacity of six common materials was tested by multiple replicate experiments with automated mini-disk infiltrometers. The tested materials included porous asphalt, porous concrete, porous brick pavers, flexible porous pavement, engineered soils, and native soils. Porous asphalt, large porous brick pavers, and curb cutout rain gardens showed the greatest infiltration rates. Most engineered porous pavements and soils performed better than the native silt loam soils. Infiltration performance was found to be related more to site design and environmental factors than material choice. Sediment trap zones in both pavements and engineered soil rain gardens were found to be beneficial to the whole site performance. Winter chloride application had a large negative impact on poured in place concrete, making it a poor choice for heavily salted areas.

Computer simulation of a space SAR using a range-sequential processor for soil moisture mapping

NASA Technical Reports Server (NTRS)

Fujita, M.; Ulaby, F. (Principal Investigator)

1982-01-01

The ability of a spaceborne synthetic aperture radar (SAR) to detect soil moisture was evaluated by means of a computer simulation technique. The computer simulation package includes coherent processing of the SAR data using a range-sequential processor, which can be set up through hardware implementations, thereby reducing the amount of telemetry involved. With such a processing approach, it is possible to monitor the earth's surface on a continuous basis, since data storage requirements can be easily met through the use of currently available technology. The Development of the simulation package is described, followed by an examination of the application of the technique to actual environments. The results indicate that in estimating soil moisture content with a four-look processor, the difference between the assumed and estimated values of soil moisture is within + or - 20% of field capacity for 62% of the pixels for agricultural terrain and for 53% of the pixels for hilly terrain. The estimation accuracy for soil moisture may be improved by reducing the effect of fading through non-coherent averaging.

Diurnal patterns of productivity of arbuscular mycorrhizal fungi revealed with the Soil Ecosystem Observatory.

PubMed

Hernandez, Rebecca R; Allen, Michael F

2013-10-01

Arbuscular mycorrhizal (AM) fungi are the most abundant plant symbiont and a major pathway of carbon sequestration in soils. However, their basic biology, including their activity throughout a 24-h day : night cycle, remains unknown. We employed the in situ Soil Ecosystem Observatory to quantify the rates of diurnal growth, dieback and net productivity of extra-radical AM fungi. AM fungal hyphae showed significantly different rates of growth and dieback over a period of 24 h and paralleled the circadian-driven photosynthetic oscillations observed in plants. The greatest rates (and incidences) of growth and dieback occurred between noon and 18:00 h. Growth and dieback events often occurred simultaneously and were tightly coupled with soil temperature and moisture, suggesting a rapid acclimation of the external phase of AM fungi to the immediate environment. Changes in the environmental conditions and variability of the mycorrhizosphere may alter the diurnal patterns of productivity of AM fungi, thereby modifying soil carbon sequestration, nutrient cycling and host plant success. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

Diurnal patterns of productivity of arbuscular mycorrhizal fungi revealed with the Soil Ecosystem Observatory

PubMed Central

Hernandez, Rebecca R; Allen, Michael F

2013-01-01

Arbuscular mycorrhizal (AM) fungi are the most abundant plant symbiont and a major pathway of carbon sequestration in soils. However, their basic biology, including their activity throughout a 24-h day : night cycle, remains unknown. We employed the in situ Soil Ecosystem Observatory to quantify the rates of diurnal growth, dieback and net productivity of extra-radical AM fungi. AM fungal hyphae showed significantly different rates of growth and dieback over a period of 24 h and paralleled the circadian-driven photosynthetic oscillations observed in plants. The greatest rates (and incidences) of growth and dieback occurred between noon and 18:00 h. Growth and dieback events often occurred simultaneously and were tightly coupled with soil temperature and moisture, suggesting a rapid acclimation of the external phase of AM fungi to the immediate environment. Changes in the environmental conditions and variability of the mycorrhizosphere may alter the diurnal patterns of productivity of AM fungi, thereby modifying soil carbon sequestration, nutrient cycling and host plant success. PMID:23844990

Infiltration performance of engineered surfaces commonly used for distributed stormwater management.

PubMed

Valinski, N A; Chandler, D G

2015-09-01

Engineered porous media are commonly used in low impact development (LID) structures to mitigate excess stormwater in urban environments. Differences in infiltrability of these LID systems arise from the wide variety of materials used to create porous surfaces and subsequent maintenance, debris loading, and physical damage. In this study, the infiltration capacity of six common materials was tested by multiple replicate experiments with automated mini-disk infiltrometers. The tested materials included porous asphalt, porous concrete, porous brick pavers, flexible porous pavement, engineered soils, and native soils. Porous asphalt, large porous brick pavers, and curb cutout rain gardens showed the greatest infiltration rates. Most engineered porous pavements and soils performed better than the native silt loam soils. Infiltration performance was found to be related more to site design and environmental factors than material choice. Sediment trap zones in both pavements and engineered soil rain gardens were found to be beneficial to the whole site performance. Winter chloride application had a large negative impact on poured in place concrete, making it a poor choice for heavily salted areas. Copyright © 2015 Elsevier Ltd. All rights reserved.

BOREAS TE-1 SSA-Fen Soil Profile Nutrient Data

NASA Technical Reports Server (NTRS)

Papagno, Andrea; Anderson, Darwin; Newcomer, Jeffrey A. (Editor); Hall, Forrest G. (Editor)

2000-01-01

The BOREAS TE-1 team collected various data to characterize the soil-plant systems in the BOREAS SSA. Particular emphasis was placed on nutrient biochemistry, the stores and transfers of organic carbon, and how the characteristics were related to measured methane fluxes. The overall traniect in the Prince Albert National Park (Saskatchewan, Canada) included the major plant communities and related soils that occurred in that section of the boreal forest. Soil physical, chemical, and biological measurements along the transect were used to characterize the static environment, which allowed them to be related to methane fluxes. Chamber techniques were used to provide a measure of methane production/uptake. Chamber measurements coupled with flask sampling were used to determine the seasonality of methane fluxes. This particular data set contains soil profile measurements of various nutrients at the SSA-Fen site. The data were collected from 23-May to 21-Oct- 1994. The data are stored in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

Scenario-targeted toxicity assessment through multiple endpoint bioassays in a soil posing unacceptable environmental risk according to regulatory screening values.

PubMed

Rodriguez-Ruiz, A; Etxebarria, J; Boatti, L; Marigómez, I

2015-09-01

Lanestosa is a chronically polluted site (derelict mine) where the soil (Lanestosa (LA) soil) exceeds screening values (SVs) of regulatory policies in force (Basque Country; Europe) for Zn, Pb and Cd. A scenario-targeted toxicity assessment was carried out on the basis of a multi-endpoint bioassay approach. Acute and chronic toxicity bioassays were conducted with selected test species (Vibrio fischeri, Dictyostelium discoideum, Lactuca sativa, Raphanus sativus and Eisenia fetida) in combination with chemical analysis of soils and elutriates and with bioaccumulation studies in earthworms. Besides, the toxicity profile was compared with that of the mine runoff (RO) soil and of a fresh artificially polluted soil (LAAPS) resembling LA soil pollutant profile. Extractability studies in LA soil revealed that Pb, Zn and Cd were highly available for exchange and/or release into the environment. Indeed, Pb and Zn were accumulated in earthworms and LA soil resulted to be toxic. Soil respiration, V. fischeri, vegetative and developmental cycles of D. discoideum and survival and juvenile production of E. fetida were severely affected. These results confirmed that LA soil had unacceptable environmental risk and demanded intervention. In contrast, although Pb and Zn concentrations in RO soil revealed also unacceptable risk, both metal extractability and toxicity were much lower than in LA soil. Thus, within the polluted site, the need for intervention varied between areas that posed dissimilar risk. Besides, since LAAPS, with a high exchangeable metal fraction, was the most toxic, ageing under in situ natural conditions seemingly contributed to attenuate LA soil risk. As a whole, combining multi-endpoint bioassays with scenario-targeted analysis (including leaching and ageing) provides reliable risk assessment in soils posing unacceptable environmental risk according to SVs, which is useful to optimise the required intervention measures.

Environmental Electrokinetics for a sustainable subsurface.

PubMed

Lima, A T; Hofmann, A; Reynolds, D; Ptacek, C J; Van Cappellen, P; Ottosen, L M; Pamukcu, S; Alshawabekh, A; O'Carroll, D M; Riis, C; Cox, E; Gent, D B; Landis, R; Wang, J; Chowdhury, A I A; Secord, E L; Sanchez-Hachair, A

2017-08-01

Soil and groundwater are key components in the sustainable management of the subsurface environment. Source contamination is one of its main threats and is commonly addressed using established remediation techniques such as in-situ chemical oxidation (ISCO), in-situ chemical reduction (ISCR; most notably using zero-valent iron [ZVI]), enhanced in-situ bioremediation (EISB), phytoremediation, soil-washing, pump-and-treat, soil vapour extraction (SVE), thermal treatment, and excavation and disposal. Decades of field applications have shown that these techniques can successfully treat or control contaminants in higher permeability subsurface materials such as sands, but achieve only limited success at sites where low permeability soils, such as silts and clays, prevail. Electrokinetics (EK), a soil remediation technique mostly recognized in in-situ treatment of low permeability soils, has, for the last decade, been combined with more conventional techniques and can significantly enhance the performance of several of these remediation technologies, including ISCO, ISCR, EISB and phytoremediation. Herein, we discuss the use of emerging EK techniques in tandem with conventional remediation techniques, to achieve improved remediation performance. Furthermore, we highlight new EK applications that may come to play a role in the sustainable treatment of the contaminated subsurface. Copyright © 2017 Elsevier Ltd. All rights reserved.

Bacterial physiological diversity in the rhizosphere of range plants in response to retorted shale stress. [Agropyron smithii Rydb; Atriplex canescens (Pursh) Nutt

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

Metzger, W.C.; Klein, D.A.; Redente, E.F.

1986-10-01

Bacterial populations were isolated from the soil-root interface and root-free regions of Agropyron smithii Rydb. and Atriplex canescens (Pursh) Nutt. grown in soil, retorted shale, or soil over shale. Bacteria isolated from retorted shale exhibited a wider range of tolerance to alkalinity and salinity and decreased growth on amino acid substrates compared with bacteria from soil and soil-over-shale environments. Exoenzyme production was only slightly affected by growth medium treatment. Viable bacterial populations were higher in the rhizosphere and rhizoplane of plants grown in retorted shale than in plants grown in soil or soil over shale. In addition, a greater numbermore » of physiological groups of rhizosphere bacteria was observed in retorted shale, compared with soil alone. Two patterns of community similarity were observed in comparisons of bacteria from soil over shale with those from soil and retorted-shale environments. Root-associated populations from soil over shale had a higher proportion of physiological groups in common with those from the soil control than those from the retorted-shale treatment. However, in non-rhizosphere populations, bacterial groups from soil over shale more closely resembled the physiological groups from retorted shale.« less

AMENDING SOILS WITH PHOSPHATE AS MEANS TO ...

EPA Pesticide Factsheets

Ingested soil and surface dust may be important contributors to elevated blood lead (Pb) levels in children exposed to Pb contaminated environments. Mitigation strategies have typically focused on excavation and removal of the contaminated soil. However, this is not always feasible for addressing widely disseminated contamination in populated areas often encountered in urban environments. The rationale for amending soils with phosphate is that phosphate will promote formation of highly insoluble Pb species (e.g., pyromorphite minerals) in soil, which will remain insoluble after ingestion and, therefore, inaccessible to absorption mechanisms in the gastrointestinal tract (GIT). Amending soil with phosphate might potentially be used in combination with other methods that reduce contact with or migration of contaminated soils, such as covering the soil with a green cap such as sod, clean soil with mulch, raised garden beds, or gravel. These remediation strategies may be less expensive and far less disruptive than excavation and removal of soil. This review evaluates evidence for efficacy of phosphate amendments for decreasing soil Pb bioavailability. Evidence is reviewed for (1) physical and chemical interactions of Pb and phosphate that would be expected to influence bioavailability, (2) effects of phosphate amendments on soil Pb bioaccessibility (i.e., predicted solubility of Pb in the GIT), and (3) results of bioavailability bioassays of amended soils con

Method for treatment of soils contaminated with organic pollutants

DOEpatents

Wickramanayake, Godage B.

1993-01-01

A method for treating soil contaminated by organic compounds wherein an ozone containing gas is treated with acid to increase the stability of the ozone in the soil environment and the treated ozone applied to the contaminated soil to decompose the organic compounds. The soil may be treated in situ or may be removed for treatment and refilled.

The Living Soil: Exploring Soil Science and Sustainable Agriculture with Your Guide, The Earthworm. Unit I.

ERIC Educational Resources Information Center

Weber, Eldon C.; And Others

This instructional packet introduces students to soil biology, ecology, and specific farming practices that promote sustainable agriculture. It helps students to discover the role of earthworms in improving the environment of all other soil-inhabiting organisms and in making the soil more fertile. The activities (classroom as well as outdoor)…

SITE EVALUATION OF SOIL AMENDMENT TECHNOLOGIES AT THE CROOKSVILLE/ROSEVILLE POTTERY AREA OF CONCERN - STAR ORGANICS SOIL RESCUE INNOVATIVE TECHNOLOGY EVALUATION REPORT (ITER)

EPA Science Inventory

Star Organics, L.L.C., of Dallas, Texas (Star Organics) has developed Soil Rescue to treat soil contaminated with metals. Star Organics claims that Soil Rescue forms metal complexes that immobilize toxic metals, thereby reducing the risk to human health and the environment. The ...

Molecular characterization of phototrophic microorganisms in the forefield of a receding glacier in the Swiss Alps

NASA Astrophysics Data System (ADS)

Frey, Beat; Bühler, Lukas; Schmutz, Stefan; Zumsteg, Anita; Furrer, Gerhard

2013-03-01

Recently deglaciated areas are ideal environments to study soil formation and primary microbial succession where phototrophic microorganisms may play a role as primary producers. The aim of our study was to investigate the cyanobacterial and green algal community composition in three different successional stages of the Damma glacier forefield in the Swiss Alps using 16S rDNA and ITS rDNA clone libraries. Cyanobacterial target sequences varied along the glacier forefield, with the highest cyanobacterial 16S rRNA gene copies found in sparsely vegetated soils. Sequence analysis revealed that the phototrophic communities were distinct in each of the three soil environments. The majority of the cyanobacterial sequences retrieved from barren soils were related to the Oscillatoriales. The diversity in sparsely vegetated soils was low, and sequences closely related to Nostoc sp. dominated. The majority of the algal phylotypes are related to members of the Trebouxiophyceae known to live as symbiotic partners in lichens. We conclude that the community composition appears to shift markedly along the chronosequence, indicating that each soil environment selects for its phototrophic community. When cyanobacteria occur together with eukaryotic microalgae, they form a rich source of organic matter and may be important contributors of carbon in nutrient-deficient deglaciated soils.

Selenium Cycling Across Soil-Plant-Atmosphere Interfaces: A Critical Review

PubMed Central

Winkel, Lenny H.E.; Vriens, Bas; Jones, Gerrad D.; Schneider, Leila S.; Pilon-Smits, Elizabeth; Bañuelos, Gary S.

2015-01-01

Selenium (Se) is an essential element for humans and animals, which occurs ubiquitously in the environment. It is present in trace amounts in both organic and inorganic forms in marine and freshwater systems, soils, biomass and in the atmosphere. Low Se levels in certain terrestrial environments have resulted in Se deficiency in humans, while elevated Se levels in waters and soils can be toxic and result in the death of aquatic wildlife and other animals. Human dietary Se intake is largely governed by Se concentrations in plants, which are controlled by root uptake of Se as a function of soil Se concentrations, speciation and bioavailability. In addition, plants and microorganisms can biomethylate Se, which can result in a loss of Se to the atmosphere. The mobilization of Se across soil-plant-atmosphere interfaces is thus of crucial importance for human Se status. This review gives an overview of current knowledge on Se cycling with a specific focus on soil-plant-atmosphere interfaces. Sources, speciation and mobility of Se in soils and plants will be discussed as well as Se hyperaccumulation by plants, biofortification and biomethylation. Future research on Se cycling in the environment is essential to minimize the adverse health effects associated with unsafe environmental Se levels. PMID:26035246

Selenium cycling across soil-plant-atmosphere interfaces: a critical review.

PubMed

Winkel, Lenny H E; Vriens, Bas; Jones, Gerrad D; Schneider, Leila S; Pilon-Smits, Elizabeth; Bañuelos, Gary S

2015-05-29

Selenium (Se) is an essential element for humans and animals, which occurs ubiquitously in the environment. It is present in trace amounts in both organic and inorganic forms in marine and freshwater systems, soils, biomass and in the atmosphere. Low Se levels in certain terrestrial environments have resulted in Se deficiency in humans, while elevated Se levels in waters and soils can be toxic and result in the death of aquatic wildlife and other animals. Human dietary Se intake is largely governed by Se concentrations in plants, which are controlled by root uptake of Se as a function of soil Se concentrations, speciation and bioavailability. In addition, plants and microorganisms can biomethylate Se, which can result in a loss of Se to the atmosphere. The mobilization of Se across soil-plant-atmosphere interfaces is thus of crucial importance for human Se status. This review gives an overview of current knowledge on Se cycling with a specific focus on soil-plant-atmosphere interfaces. Sources, speciation and mobility of Se in soils and plants will be discussed as well as Se hyperaccumulation by plants, biofortification and biomethylation. Future research on Se cycling in the environment is essential to minimize the adverse health effects associated with unsafe environmental Se levels.

Investigation on the dominant factors controlling the spatio-temporal distribution of soil moisture in experimental grasslands

NASA Astrophysics Data System (ADS)

Schwichtenberg, G.; Hildebrandt, A.; Samaniego-Eguiguren, L.; Kreutziger, Y.; Attinger, S.

2009-04-01

The spatio-temporal distribution of soil moisture in the unsaturated zone influences the vegetation growth, governs the runoff generation processes as well as the energy balance at the interface between biosphere and the atmosphere, by influencing evapotranspiration. A better understanding of the spatio-temporal variability and dependence of soil moisture on living versus abiotic environment would lead to an improved representation of the soil-vegetation-atmosphere processes in hydrological and climate models. The Jena Experiment site (Germany) was established October 2001 in order to analyse the interaction between plant diversity and ecosystem processes. The main experiment covers 92 plots of 20 x 20 m arranged into a grid, on which a mixture of up to 60 grassland species and of one to four plant functional groups have been seeded. Each of these plots is equipped with at least one measurement tube for soil moisture. Measurements have been conducted weekly for four growing seasons (SSF). Here, we use geostatistical methods, like variograms and multivariate regressions, to investigate in how far abiotic environment and ecosystem explain the spatial and temporal variation of soil moisture at the Jena Experiment site. We test the influence of the soil environment, biodiversity, leaf area index and groundwater table. The poster will present the results of this analysis.

Recovery of soil unicellular eukaryotes: an efficiency and activity analysis on the single cell level.

PubMed

Lentendu, Guillaume; Hübschmann, Thomas; Müller, Susann; Dunker, Susanne; Buscot, François; Wilhelm, Christian

2013-12-01

Eukaryotic unicellular organisms are an important part of the soil microbial community, but they are often neglected in soil functional microbial diversity analysis, principally due to the absence of specific investigation methods in the special soil environment. In this study we used a method based on high-density centrifugation to specifically isolate intact algal and yeast cells, with the aim to analyze them with flow cytometry and sort them for further molecular analysis such as deep sequencing. Recovery efficiency was tested at low abundance levels that fit those in natural environments (10(4) to 10(6) cells per g soil). Five algae and five yeast morphospecies isolated from soil were used for the testing. Recovery efficiency was between 1.5 to 43.16% and 2 to 30.2%, respectively, and was dependent on soil type for three of the algae. Control treatments without soil showed that the majority of cells were lost due to the method itself (58% and 55.8% respectively). However, the cell extraction technique did not much compromise cell vitality because a fluorescein di-acetate assay indicated high viability percentages (73.3% and 97.2% of cells, respectively). The low abundant algae and yeast morphospecies recovered from soil were cytometrically analyzed and sorted. Following, their DNA was isolated and amplified using specific primers. The developed workflow enables isolation and enrichment of intact autotrophic and heterotrophic soil unicellular eukaryotes from natural environments for subsequent application of deep sequencing technologies. Copyright © 2013 Elsevier B.V. All rights reserved.

Nitrogen and crop rotation as drivers of the maize-associated soil microbiome

USDA-ARS?s Scientific Manuscript database

Microbes inhabit an exciting and interesting array of environments, exhibiting striking amounts of diversity and variation. The soil microbiome is one of the most dynamic and diverse microbial environments, where bacteria, fungi, and plant roots all interact to shape food networks and drive ecosyste...

Plant Community and Soil Environment Response to Summer Fire in the Northern Great Plains

USDA-ARS?s Scientific Manuscript database

Fire is a keystone process in many ecosystems, especially grasslands. However, documentation of plant community and soil environment responses to fire is limited for semiarid grasslands relative to that for mesic grasslands. Replicated summer fire research is lacking, but much needed because summe...

Selenium cycling across soil-plant atmosphere interfaces: a critical review

USDA-ARS?s Scientific Manuscript database

Selenium (Se) is an essential element for humans and animals, which occurs ubiquitously in the environment. It is present in trace amounts in both organic and inorganic forms in marine and freshwater systems, soils, biomass, and in the atmosphere. Low Se levels in certain terrestrial environments ha...

40 CFR 268.49 - Alternative LDR treatment standards for contaminated soil.

Code of Federal Regulations, 2014 CFR

2014-07-01

... for contaminated soil. 268.49 Section 268.49 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... treatment standards for contaminated soil. (a) Applicability. You must comply with LDRs prior to placing soil that exhibits a characteristic of hazardous waste, or exhibited a characteristic of hazardous...

40 CFR 264.114 - Disposal or decontamination of equipment, structures and soils.

Code of Federal Regulations, 2014 CFR

2014-07-01

... equipment, structures and soils. 264.114 Section 264.114 Protection of Environment ENVIRONMENTAL PROTECTION... of equipment, structures and soils. During the partial and final closure periods, all contaminated equipment, structures and soils must be properly disposed of or decontaminated unless otherwise specified in...

40 CFR 264.114 - Disposal or decontamination of equipment, structures and soils.

Code of Federal Regulations, 2012 CFR

2012-07-01

... equipment, structures and soils. 264.114 Section 264.114 Protection of Environment ENVIRONMENTAL PROTECTION... of equipment, structures and soils. During the partial and final closure periods, all contaminated equipment, structures and soils must be properly disposed of or decontaminated unless otherwise specified in...

40 CFR 264.114 - Disposal or decontamination of equipment, structures and soils.

Code of Federal Regulations, 2011 CFR

2011-07-01

... equipment, structures and soils. 264.114 Section 264.114 Protection of Environment ENVIRONMENTAL PROTECTION... of equipment, structures and soils. During the partial and final closure periods, all contaminated equipment, structures and soils must be properly disposed of or decontaminated unless otherwise specified in...

40 CFR 268.49 - Alternative LDR treatment standards for contaminated soil.

Code of Federal Regulations, 2011 CFR

2011-07-01

... for contaminated soil. 268.49 Section 268.49 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... treatment standards for contaminated soil. (a) Applicability. You must comply with LDRs prior to placing soil that exhibits a characteristic of hazardous waste, or exhibited a characteristic of hazardous...

40 CFR 268.49 - Alternative LDR treatment standards for contaminated soil.

Code of Federal Regulations, 2012 CFR

2012-07-01

... for contaminated soil. 268.49 Section 268.49 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... treatment standards for contaminated soil. (a) Applicability. You must comply with LDRs prior to placing soil that exhibits a characteristic of hazardous waste, or exhibited a characteristic of hazardous...

40 CFR 268.49 - Alternative LDR treatment standards for contaminated soil.

Code of Federal Regulations, 2013 CFR

2013-07-01

... for contaminated soil. 268.49 Section 268.49 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... treatment standards for contaminated soil. (a) Applicability. You must comply with LDRs prior to placing soil that exhibits a characteristic of hazardous waste, or exhibited a characteristic of hazardous...

40 CFR 268.49 - Alternative LDR treatment standards for contaminated soil.

Code of Federal Regulations, 2010 CFR

2010-07-01

... for contaminated soil. 268.49 Section 268.49 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... treatment standards for contaminated soil. (a) Applicability. You must comply with LDRs prior to placing soil that exhibits a characteristic of hazardous waste, or exhibited a characteristic of hazardous...

40 CFR 264.114 - Disposal or decontamination of equipment, structures and soils.

Code of Federal Regulations, 2010 CFR

2010-07-01

... equipment, structures and soils. 264.114 Section 264.114 Protection of Environment ENVIRONMENTAL PROTECTION... of equipment, structures and soils. During the partial and final closure periods, all contaminated equipment, structures and soils must be properly disposed of or decontaminated unless otherwise specified in...

40 CFR 264.114 - Disposal or decontamination of equipment, structures and soils.

Code of Federal Regulations, 2013 CFR

2013-07-01

... equipment, structures and soils. 264.114 Section 264.114 Protection of Environment ENVIRONMENTAL PROTECTION... of equipment, structures and soils. During the partial and final closure periods, all contaminated equipment, structures and soils must be properly disposed of or decontaminated unless otherwise specified in...

Soil & Tillage Research: Publication history and assessment of progress

USDA-ARS?s Scientific Manuscript database

The journal, Soil and Tillage Research, is concerned with the changes in physical, chemical and biological properties and processes of the soil environment brought about by soil tillage and field traffic, their effects on both below- and above-ground environmental quality, crop establishment, root d...

Contribution of soil fauna to soil functioning in degraded environments: a multidisciplinary approach

NASA Astrophysics Data System (ADS)

Gargiulo, Laura; Mele, Giacomo; Moradi, Jabbar; Kukla, Jaroslav; Jandová, Kateřina; Frouz, Jan

2016-04-01

The restoration of the soil functions is essential for the recovery of highly degraded sites and, consequently, the study of the soil fauna role in the soil development in such environments has great potential from a practical point of view. The soils of the post-mining sites represent unique models for the study of the natural ecological succession because mining creates similar environments characterized by the same substrate, but by different ages according to the year of closure of mines. The aim of this work was to assess the contribution of different species of macrofauna on the evolution of soil structure and on the composition and activity of the microbial community in soil samples subjected to ecological restoration or characterized by spontaneous ecological succession. For this purpose, an experimental test was carried out in two sites characterized by different post-mining conditions: 1) natural succession, 2) reclamation with planting trees. These sites are located in the post-mining area of Sokolov (Czech Republic). For the experimental test repacked soil cores were prepared in laboratory with sieved soil sampled from the two sites. The soil cores were prepared maintaining the sequence of soil horizons present in the field. These samples were inoculated separately with two genera of earthworms (Lumbricus and Aporrectodea) and two of centipedes (Julida and Polydesmus). In particular, based on their body size, were inoculated for each cylinder 2 individuals of millipedes, 1 individual of Lumbricus and 4 individuals of Aporrectodea. For each treatment and for control samples 5 replicates were prepared and all samples were incubated in field for 1 month in the two original sampling sites. After the incubation the samples were removed from the field and transported in laboratory in order to perform the analysis of microbial respiration, of PLFA (phospholipid-derived fatty acids) and ergosterol contents and finally for the characterization of soil structure. All replicates were subjected to soil respiration measurement by means of chemical titration method. Then some replicates were destructively analyzed for PLFA and ergosterol and others were used for the 3D soil image analysis of the soil pore system. The soil cores were imaged using X-ray microtomography and three-dimensional image processing was performed in order to obtain 3D reconstructions and preliminary analysis of the identified biopores. The experimental approach used in this multidisciplinary study showed a promising potential to provide new useful information about the widely differentiated contribution of many types of macrofauna to the formation of the soil pore system and to the development of the soil microbial functions in different types of environments.

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

Detection of N2O-producing fungi in environment using nitrite reductase gene (nirK)-targeting primers.

PubMed

Chen, Huaihai; Yu, Fangbo; Shi, Wei

2016-12-01

Fungal denitrification has been increasingly investigated, but its community ecology is poorly understood due to the lack of culture-independent tools. In this work, four pairs of nirK-targeting primers were designed and evaluated for primer specificity and efficiency using thirty N 2 O-producing fungal cultures and an agricultural soil. All primers amplified nirK from fungi and soil, but their efficiency and specificity were different. A primer set, FnirK_F3/R2 amplified ∼80 % of tested fungi, including Aspergillus, Fusarium, Penicillium, and Trichoderma, as compared to ∼40-70 % for other three primers. The nirK fragments of fungal and soil DNA amplified by FnirK_F3/R2 were phylogenetically related to denitrifying fungi in the orders Eurotiales, Hypocreales, and Sordariales; and clone sequences were also distributed in the clusters of Chaetomium, Metarhizium, and Myceliophthora that were uncultured from soil in our previous work. This proved the wide-range capability of primers for amplifying diverse denitrifying fungi from environment. However, our primers and recently-developed other primers amplified bacterial nirK from soil and this co-amplification of fungal and bacterial nirK was theoretically discussed. The FnirK_F3/R2 was further compared with published primers; results from clone libraries demonstrated that FnirK_F3/R2 was more specifically targeted on fungi and had broader taxonomical coverage than some others. Copyright © 2016 British Mycological Society. Published by Elsevier Ltd. All rights reserved.