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Sample records for agricultural soil samples

  1. Sampling for Soil Carbon Stock Assessment in Rocky Agricultural Soils

    NASA Technical Reports Server (NTRS)

    Beem-Miller, Jeffrey P.; Kong, Angela Y. Y.; Ogle, Stephen; Wolfe, David

    2016-01-01

    Coring methods commonly employed in soil organic C (SOC) stock assessment may not accurately capture soil rock fragment (RF) content or soil bulk density (rho (sub b)) in rocky agricultural soils, potentially biasing SOC stock estimates. Quantitative pits are considered less biased than coring methods but are invasive and often cost-prohibitive. We compared fixed-depth and mass-based estimates of SOC stocks (0.3-meters depth) for hammer, hydraulic push, and rotary coring methods relative to quantitative pits at four agricultural sites ranging in RF content from less than 0.01 to 0.24 cubic meters per cubic meter. Sampling costs were also compared. Coring methods significantly underestimated RF content at all rocky sites, but significant differences (p is less than 0.05) in SOC stocks between pits and corers were only found with the hammer method using the fixed-depth approach at the less than 0.01 cubic meters per cubic meter RF site (pit, 5.80 kilograms C per square meter; hammer, 4.74 kilograms C per square meter) and at the 0.14 cubic meters per cubic meter RF site (pit, 8.81 kilograms C per square meter; hammer, 6.71 kilograms C per square meter). The hammer corer also underestimated rho (sub b) at all sites as did the hydraulic push corer at the 0.21 cubic meters per cubic meter RF site. No significant differences in mass-based SOC stock estimates were observed between pits and corers. Our results indicate that (i) calculating SOC stocks on a mass basis can overcome biases in RF and rho (sub b) estimates introduced by sampling equipment and (ii) a quantitative pit is the optimal sampling method for establishing reference soil masses, followed by rotary and then hydraulic push corers.

  2. Elemental analysis of agricultural soil samples by particle induced X-ray emission (PIXE) technique

    NASA Astrophysics Data System (ADS)

    Cruvinel, Paulo E.; Flocchini, Robert G.; Artaxo, Paulo; Crestana, Silvio; Herrmann, Paulo S. P., Jr.

    1999-04-01

    In agriculture, elements essential to vital processes are also called nutrients. A suitable and reliable particle induced X-ray emission (PIXE) methodology for content determination of essential nutrients in soil samples was developed and its effectiveness proved. The PIXE method is applied to intermediate thickness samples, whose mass per area unit are smaller than 1 μg/cm 2. Precision and accuracy of the method was estimated after repeated measurements of a single reference material: CRM PACS-2 (estuarine sediment) with a matrix quite similar to the soil samples measured. This paper reports the results of elemental measurements in soil samples. A discussion of agricultural soil sample preparation for PIXE analysis is also presented.

  3. 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

  4. GEMAS: Colours of dry and moist agricultural soil samples of Europe

    NASA Astrophysics Data System (ADS)

    Klug, Martin; Fabian, Karl; Reimann, Clemens

    2016-04-01

    High resolution HDR colour images of all Ap samples from the GEMAS survey were acquired using a GeoTek Linescan camera. Three measurements of dry and wet samples with increasing exposure time and increasing illumination settings produced a set of colour images at 50μm resolution. Automated image processing was used to calibrate the six images per sample with respect to the synchronously measured X-Rite colorchecker chart. The calibrated images were then fit to Munsell soil colours that were measured in the same way. The results provide overview maps of dry and moist European soil colours. Because colour is closely linked to iron mineralogy, carbonate, silicate and organic carbon content the results can be correlated to magnetic, mineralogical, and geochemical properties. In combination with the full GEMAS chemical and physical measurements, this yields a valuable data set for calibration and interpretation of visible satellite colour data with respect to chemical composition and geological background, soil moisture, and soil degradation. This data set will help to develop new methods for world-wide characterization and monitoring of agricultural soils which is essential for quantifying geologic and human impact on the critical zone environment. It furthermore enables the scientific community and governmental authorities to monitor consequences of climatic change, to plan and administrate economic and ecological land use, and to use the data set for forensic applications.

  5. Radiometric assessment of natural radioactivity levels of agricultural soil samples collected in Dakahlia, Egypt.

    PubMed

    Issa, Shams A M

    2013-01-01

    Determination of the natural radioactivity has been carried out, by using a gamma-ray spectrometry [NaI (Tl) 3″ × 3″] system, in surface soil samples collected from various locations in Dakahlia governorate, Egypt. These locations form the agriculturally important regions of Egypt. The study area has many industries such as chemical, paper, organic fertilisers and construction materials, and the soils of the study region are used as a construction material. Therefore, it becomes necessary to study the natural radioactivity levels in soil to assess the dose for the population in order to know the health risks. The activity concentrations of (226)Ra, (232)Th and (40)K in the soil ranged from 5.7 ± 0.3 to 140 ± 7, from 9.0 ± 0.4 to 139 ± 7 and from 22 ± 1 to 319 ± 16 Bq kg(-1), respectively. The absorbed dose rate, annual effective dose rate, radium equivalent (Req), excess lifetime cancer risk, hazard indices (Hex and Hin) and annual gonadal dose equivalent, which resulted from the natural radionuclides in the soil were calculated.

  6. Speciation of vanadium in coal mining, industrial, and agricultural soil samples using different extractants and heating systems.

    PubMed

    Khan, Sumaira; Kazi, Tasneem Gul; Afridi, Hassan Imran; Kolachi, Nida Fatima; Ullah, Naeem; Dev, Kapil

    2013-01-01

    A fast microwave-assisted extraction procedure was developed for the speciation of vanadium (V) species in soil samples collected from the vicinity of the Lakhra coal power plant (situated near a coal mining area) and industrial and agricultural areas. Soil samples were treated with two extracting reagents, (NH4)2HPO4 (0.2-1 M) and Na2CO3 (0.1-0.5 M), and heated by conventional and microwave methods for different time intervals to extract V+5 species. The V+4 and total V were extracted from filtration residue and the same subsamples of soil by treating with the acid mixture of HNO3-HCl-HClO4-H2SO4 (1:1:1:1, v/v/v/v). No significant difference between V+5 contents obtained by conventional heating and microwave-assisted extraction was observed (P = 0.485). The extraction efficiency of 0.6 M (NH4)2HPO4 for V+5 was lower (4-7%) than that obtained by 0.2 M Na2CO3 solution. The levels of V+5 were higher in soil samples collected from the vicinity of the Lakhra coal power plant and industrial areas, compared to those obtained from agricultural soil.

  7. Determination of insoluble soap in agricultural soil and sewage sludge samples by liquid chromatography with ultraviolet detection.

    PubMed

    Cantarero, Samuel; Zafra-Gómez, Alberto; Ballesteros, Oscar; Navalón, Alberto; Vílchez, José L; Crovetto, Guillermo; Verge, Coral; de Ferrer, Juan A

    2010-11-01

    We have developed a new analytical procedure for determining insoluble Ca and Mg fatty acid salts (soaps) in agricultural soil and sewage sludge samples. The number of analytical methodologies that focus in the determination of insoluble soap salts in different environmental compartments is very limited. In this work, we propose a methodology that involves a sample clean-up step with petroleum ether to remove soluble salts and a conversion of Ca and Mg insoluble salts into soluble potassium salts using tripotassium ethylenediaminetetraacetate salt and potassium carbonate, followed by the extraction of analytes from the samples using microwave-assisted extraction with methanol. An improved esterification procedure using 2,4-dibromoacetophenone before the liquid chromatography with ultraviolet detection analysis also has been developed. The absence of matrix effect was demonstrated with two fatty acid Ca salts that are not commercial and are never detected in natural samples (C₁₃:₀ and C₁₇:₀). Therefore, it was possible to evaluate the matrix effect because both standards have similar environmental behavior (adsorption and precipitation) to commercial soaps (C₁₀:₀) to C₁₈:₀). We also studied the effect of the different variables on the clean-up, the conversion of Ca soap, and the extraction and derivatization procedures. The quantification limits found ranged from 0.4 to 0.8 mg/kg. The proposed method was satisfactorily applied for the development of a study on soap behavior in agricultural soil and sewage sludge samples.

  8. Enantioseparation and determination of the chiral phenylpyrazole insecticide ethiprole in agricultural and environmental samples and its enantioselective degradation in soil.

    PubMed

    Zhang, Qing; Shi, Haiyan; Gao, Beibei; Tian, Mingming; Hua, Xiude; Wang, Minghua

    2016-01-15

    An effective method for the enantioselective determination of ethiprole enantiomers in agricultural and environmental samples was developed. The effects of solvent extraction, mobile phase and thermodynamic parameters for chiral recognition were fully investigated. Complete enantioseparation of the ethiprole enantiomers was achieved on a Lux Cellulose-2 column. The stereochemical structures of ethiprole enantiomers were also determined, and (R)-(+)-ethiprole was first eluted. The average recoveries were 82.7-104.9% with intra-day RSD of 1.7-8.2% in soil, cucumber, spinach, tomato, apple and peach under optimal conditions. Good linearity (R(2)≥0.9991) was obtained for all the matrix calibration curves within a range of 0.1 to 10 mg L(-1). The limits of detection for both enantiomers were estimated to be 0.008 mg kg(-1) in soil, cucumber, spinach and tomato and 0.012 mg kg(-1) in apple and peach, which were lower than the maximum residue levels established in Japan. The results indicate that the proposed method is convenient and reliable for the enantioselective detection of ethiprole in agricultural and environmental samples. The behavior of ethiprole in soil was studied under field conditions and the enantioselective degradation was observed with enantiomer fraction values varying from 0.494 to 0.884 during the experiment. The (R)-(+)-ethiprole (t1/2=11.6 d) degraded faster than (S)-(-)-ethiprole (t1/2=34.7 d). This report is the first describe a chiral analytical method and enantioselective behavior of ethiprole, and these results should be extremely useful for the risk evaluation of ethiprole in food and environmental safety.

  9. Soil Erosion and Agricultural Sustainability

    NASA Astrophysics Data System (ADS)

    Montgomery, D. R.

    2009-04-01

    Data drawn from a global compilation of studies support the long articulated contention that erosion rates from conventionally plowed agricultural fields greatly exceed rates of soil production, erosion under native vegetation, and long-term geological erosion. Whereas data compiled from around the world show that soil erosion under conventional agriculture exceeds both rates of soil production and geological erosion rates by up to several orders of magnitude, similar global distributions of soil production and geological erosion rates suggest an approximate balance. Net soil erosion rates in conventionally plowed fields on the order of 1 mm/yr can erode typical hillslope soil profiles over centuries to millennia, time-scales comparable to the longevity of major civilizations. Well-documented episodes of soil loss associated with agricultural activities date back to the introduction of erosive agricultural methods in regions around the world, and stratigraphic records of accelerated anthropogenic soil erosion have been recovered from lake, fluvial, and colluvial stratigraphy, as well as truncation of soil stratigraphy (such as truncated A horizons). A broad convergence in the results from studies based on various approaches employed to study ancient soil loss and rates of downstream sedimentation implies that widespread soil loss has accompanied human agricultural intensification in examples drawn from around the world. While a broad range of factors, including climate variability and society-specific social and economic contexts — such as wars or colonial relationships — all naturally influence the longevity of human societies, the ongoing loss of topsoil inferred from studies of soil erosion rates in conventional agricultural systems has obvious long-term implications for agricultural sustainability. Consequently, modern agriculture — and therefore global society — faces a fundamental question over the upcoming centuries. Can an agricultural system

  10. Soil moisture: Some fundamentals. [agriculture - soil mechanics

    NASA Technical Reports Server (NTRS)

    Milstead, B. W.

    1975-01-01

    A brief tutorial on soil moisture, as it applies to agriculture, is presented. Information was taken from books and papers considered freshman college level material, and is an attempt to briefly present the basic concept of soil moisture and a minimal understanding of how water interacts with soil.

  11. Simultaneous determination of florfenicol with its metabolite based on modified quick, easy, cheap, effective, rugged, and safe sample pretreatment and evaluation of their degradation behavior in agricultural soils.

    PubMed

    Xu, Mingfei; Qian, Mingrong; Zhang, Hu; Ma, Junwei; Wang, Jianmei; Wu, Huizhen

    2015-01-01

    A simple and simultaneous method for the determination of florfenicol and its metabolite florfenicol amine in agricultural soils using modified quick, easy, cheap, effective, rugged, and safe sample pretreatment and reversed-phase high-performance liquid chromatography with tandem mass spectrometry is presented. Florfenicol and its metabolite florfenicol amine residues in agricultural soils were extracted with alkalized acetonitrile and an aliquot was cleaned up with Si(CH2)3NH(CH2)2NH2 and C18 sorbent, which were powder materials. High-performance liquid chromatography with tandem mass spectrometry was applied to simultaneously determine the level of florfenicol and florfenicol amine in agricultural soils. Excellent linearity was achieved for florfenicol and florfenicol amine over a range of concentrations from 0.1-500 μg/L with coefficients more than 0.99. Average recoveries at four different levels (0.005, 0.05, 0.5, and 5.0 mg/kg) for florfenicol and florfenicol amine ranged from 73.6-94.9% with relative standard deviations of 2.9-12.5%. The limits of detection for florfenicol and florfenicol amine in agricultural soils were 2.0 μg/kg, and the limits of quantification were 6.0 μg/kg. Based on this method, the degradation behavior of florfenicol and its metabolite florfenicol amine in three soils (Nanchang, Hangzhou, and Changchun) under sterilized and native conditions was investigated and the transformation rate of florfenicol amine from florfenicol was evaluated.

  12. Modeling biogeochemistry in agricultural soils

    SciTech Connect

    Li, C.; Frolking, S.; Harriss, R.

    1994-09-01

    An existing model of C and N dynamics in soils was supplemented with a plant growth submodel and cropping practice routines (fertilization, irrigation, tillage, crop rotation, and manure amendments) to study the biogeochemistry of soil carbon in arable lands. The new model was validated against field results for short-term (1-9 years) decomposition experiments, the seasonal pattern of soil CO{sub 2} respiration, and long-term (100 years) soil carbon storage dynamics. A series of sensitivity runs investigated the impact of varying agricultural practices on soil organic carbon (SOC) sequestration. The tests were simulated for corn (maize) plots over a range of soil and climate conditions typical of the United States. The largest carbon sequestration occurred with manure additions; the results were very sensitive to soil texture (more clay led to greater sequestration). Increased N fertilization generally enhanced carbon sequestration, but the results were sensitive to soil texture, initial soil carbon content, and annual precipitation. Reduced tillage also generally (but not always) increased SOC content, through the results were very sensitive to soil texture, initial SOC content, and annual precipitation. A series of long-term simulations investigated the SOC equilibrium for various agricultural practices, soil and climate conditions, and crop rotations. Equilibrium SOC content increased with decreasing temperatures, increasing clay content, enhanced N fertilization, manure amendments, and crops with higher residue yield. Time to equilibrium appears to be one hundred to several hundred years. In all cases, equilibration time was longer for increasing SOC content than for decreasing SOC content. Efforts to enhance carbon sequestration in agricultural soils would do well to focus on those specific areas and agricultural practices with the greatest potential for increasing soil carbon content. 64 refs., 13 figs., 5 tabs.

  13. The magnetic susceptibility of European agricultural soils

    NASA Astrophysics Data System (ADS)

    Fabian, K.; Reimann, C.

    2012-04-01

    The GEMAS (Geochemical mapping of agricultural soils) project, a cooperation project between EuroGeoSurveys and Eurometaux, aims at providing soil quality data for Europe. Samples of arable soil were taken during 2008 at an average density of 1 site/2500 km2 covering the member states of the European Union (except Malta and Romania) and several neighbouring countries (e.g., Norway, Serbia, Ukraine). While the primary aim of the GEMAS project is to produce REACH (Registration, Evaluation and Authorisation of CHemicals - EC, 2006) consistent soil geochemistry data at the continental scale, the data set is also optimally apt to provide the first continental scale overview of magnetic properties in European soils. Soil samples from the upper 20 cm were taken as composites from 5 sites spread over a ca. 100 m2 area in a large agricultural field (Ap-sample). The samples were air dried and sieved to pass a 2 mm nylon screen. Weight normalized magnetic susceptibility of these dried samples was measured using a Sapphire Instruments SI2B susceptibility meter with dynamic background removal. The here presented maps of magnetic susceptibility in relation to geochemical composition and geological structures for the first time allow to outline the large scale influence of tectonics and climate on magnetic mineral concentration in European soils. The data set also provides the background variability for regional studies aiming to relate magnetic susceptibility of soils to local contamination sources.

  14. Inherent agricultural constraints in Allegheny Plateau soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    World population increases demand increased agricultural production. This can be accomplished through improved cultivars and production techniques or increased use of previously marginal agricultural regions. In the Allegheny Plateau (AP) region of the Appalachian Mountains, acid soils with toxic ...

  15. Soil Organic Carbon dynamics in agricultural soils of Veneto Region

    NASA Astrophysics Data System (ADS)

    Bampa, F. B.; Morari, F. M.; Hiederer, R. H.; Toth, G. T.; Giandon, P. G.; Vinci, I. V.; Montanarella, L. M.; Nocita, M.

    2012-04-01

    One of the eight soil threats expressed in the European Commission's Thematic Strategy for Soil Protection (COM (2006)231 final) it's the decline in Soil Organic Matter (SOM). His preservation is recognized as with the objective to ensure that the soils of Europe remain healthy and capable of supporting human activities and ecosystems. One of the key goals of the strategy is to maintain and improve Soil Organic Carbon (SOC) levels. As climate change is identified as a common element in many of the soil threats, the European Commission (EC) intends to assess the actual contribution of the soil protection to climate change mitigation and the effects of climate change on the possible depletion of SOM. A substantial proportion of European land is occupied by agriculture, and consequently plays a crucial role in maintaining natural resources. Organic carbon preservation and sequestration in the EU's agricultural soils could have some potential to mitigate the effects of climate change, particularly linked to preventing certain land use changes and maintaining SOC stocks. The objective of this study is to assess the SOC dynamics in agricultural soils (cropland and grassland) at regional scale, focusing on changes due to land use. A sub-objective would be the evaluation of the most used land management practices and their effect on SOC content. This assessment aims to determine the geographical distribution of the potential GHG mitigation options, focusing on hot spots in the EU, where mitigation actions would be particularly efficient and is linked with the on-going work in the JRC SOIL Action. The pilot area is Veneto Region. The data available are coming from different sources, timing and involve different variables as: soil texture, climate, soil disturbance, managements and nutrients. The first source of data is the LUCAS project (Land Use/Land Cover Area Frame statistical Survey). Started in 2001, the LUCAS project aims to monitor changes in land cover/use and

  16. Automatic Collection of Rock and Soil Samples

    NASA Technical Reports Server (NTRS)

    Kyrias, G. M.

    1982-01-01

    Proposed machine would sample rock or soil automatically. Mounted on a wheeled or tracked vehicle, machine positions drill for cut at any angle from horizontal to vertical, moves power head to drive drill into cut, and stores drilled core in a container. New concept may also be useful in terrestrial agricultural and geologic surveys.

  17. Intensive agriculture reduces soil biodiversity across Europe.

    PubMed

    Tsiafouli, Maria A; Thébault, Elisa; Sgardelis, Stefanos P; de Ruiter, Peter C; van der Putten, Wim H; Birkhofer, Klaus; Hemerik, Lia; de Vries, Franciska T; Bardgett, Richard D; Brady, Mark Vincent; Bjornlund, Lisa; Jørgensen, Helene Bracht; Christensen, Sören; Hertefeldt, Tina D'; Hotes, Stefan; Gera Hol, W H; Frouz, Jan; Liiri, Mira; Mortimer, Simon R; Setälä, Heikki; Tzanopoulos, Joseph; Uteseny, Karoline; Pižl, Václav; Stary, Josef; Wolters, Volkmar; Hedlund, Katarina

    2015-02-01

    Soil biodiversity plays a key role in regulating the processes that underpin the delivery of ecosystem goods and services in terrestrial ecosystems. Agricultural intensification is known to change the diversity of individual groups of soil biota, but less is known about how intensification affects biodiversity of the soil food web as a whole, and whether or not these effects may be generalized across regions. We examined biodiversity in soil food webs from grasslands, extensive, and intensive rotations in four agricultural regions across Europe: in Sweden, the UK, the Czech Republic and Greece. Effects of land-use intensity were quantified based on structure and diversity among functional groups in the soil food web, as well as on community-weighted mean body mass of soil fauna. We also elucidate land-use intensity effects on diversity of taxonomic units within taxonomic groups of soil fauna. We found that between regions soil food web diversity measures were variable, but that increasing land-use intensity caused highly consistent responses. In particular, land-use intensification reduced the complexity in the soil food webs, as well as the community-weighted mean body mass of soil fauna. In all regions across Europe, species richness of earthworms, Collembolans, and oribatid mites was negatively affected by increased land-use intensity. The taxonomic distinctness, which is a measure of taxonomic relatedness of species in a community that is independent of species richness, was also reduced by land-use intensification. We conclude that intensive agriculture reduces soil biodiversity, making soil food webs less diverse and composed of smaller bodied organisms. Land-use intensification results in fewer functional groups of soil biota with fewer and taxonomically more closely related species. We discuss how these changes in soil biodiversity due to land-use intensification may threaten the functioning of soil in agricultural production systems.

  18. Activity concentration of caesium-137 in agricultural soils.

    PubMed

    Aslani, Mahmoud A A; Aytas, Sule; Akyil, Sema; Yaprak, Gunseli; Yener, Gungor; Eral, Meral

    2003-01-01

    In this study, we measured 137Cs activity concentrations in the soil samples taken from agricultural lands in the Buyuk Menderes Basin in Turkey in 1997 and 1998. The soil samples were collected from 42 sites in this Basin. The activity concentration of 137Cs was found to range between 2.81+/-0.17 Bq.kg(-1) and 20.75+/-0.29 Bq.kg(-1). The effect of organic matter, clay, silt and sand contents and pH of the soil on the relative adsorption of the 137Cs on the soil surface were also studied.

  19. Are Mexican agricultural farmlands PCDD/F soil reservoirs?

    PubMed

    Haro-García, Luis; Villa-Ibarra, Martín; Chaín-Castro, Teresita de Jesús; Lastra-Rodríguez, Angel; Juárez-Pérez, Cuauhtémoc Arturo; Aguilar-Madrid, Guadalupe; Sánchez-Escalante, Vanessa Crystal; Brito-Zurita, Olga Rosa

    2012-06-01

    Our aim was to identify polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzo-p-furans (PCDFs) in agricultural farmland soils in the Northwest of Mexico. We obtained ≈50 g of soil in five Yaqui Valley (VY) agricultural fields in the north-western Mexican State of Sonora and in five Culiacán Valley (VC) agricultural fields in the north-western Mexican State of Sinaloa. Fields with minimal tillage, with ferti-irrigation, and those with intensive aerial and manual tillage were included. All soil samples were subjected to the chemical activated luciferase gene expression (CALUX(®)) test to determine PCDD/F. On average, samples contained 4.2 ± 1.2 PCDD/F ppt TEQ; VY soil samples contained 4.72 ± 1.23 PCDD/F ppt TEQ, while VC soil samples showed 3.6 ± 1.1 PCDD/F ppt TEQ (p = 0.47). On considering tillage-type, in agricultural fields catalogued as intensive tillage, PCDD/F concentrations were 4.40 ± 0.43 in agricultural fields catalogued as intensive tillage, while in farmlands of another tillage-type these concentrations were slightly higher (5.53 ± 0.8).

  20. SAMPLING VIRUSES FROM SOIL

    EPA Science Inventory

    This chapter describes in detail methods for detecting viruses of bacteria and humans in soil. Methods also are presented for the assay of these viruses. Reference sources are provided for information on viruses of plants.

  1. Eukaryotic diversity in historical soil samples.

    PubMed

    Moon-van der Staay, Seung Yeo; Tzeneva, Vesela A; van der Staay, Georg W M; de Vos, Willem M; Smidt, Hauke; Hackstein, Johannes H P

    2006-09-01

    The eukaryotic biodiversity in historical air-dried samples of Dutch agricultural soil has been assessed by random sequencing of an 18S rRNA gene library and by denaturing gradient gel electrophoresis. Representatives of nearly all taxa of eukaryotic soil microbes could be identified, demonstrating that it is possible to study eukaryotic microbiota in samples from soil archives that have been stored for more than 30 years at room temperature. In a pilot study, 41 sequences were retrieved that could be assigned to fungi and a variety of aerobic and anaerobic protists such as cercozoans, ciliates, xanthophytes (stramenopiles), heteroloboseans, and amoebozoans. A PCR-denaturing gradient gel electrophoresis analysis of samples collected between 1950 and 1975 revealed significant changes in the composition of the eukaryotic microbiota.

  2. Determination of selected pesticides in water samples adjacent to agricultural fields and removal of organophosphorus insecticide chlorpyrifos using soil bacterial isolates

    NASA Astrophysics Data System (ADS)

    Hossain, M. S.; Chowdhury, M. Alamgir Zaman; Pramanik, Md. Kamruzzaman; Rahman, M. A.; Fakhruddin, A. N. M.; Alam, M. Khorshed

    2015-06-01

    The use of pesticide for crops leads to serious environmental pollution, therefore, it is essential to monitor and develop approaches to remove pesticide from contaminated environment. In this study, water samples were collected to monitor pesticide residues, and degradation of chlorpyrifos was also performed using soil bacteria. Identification of pesticide residues and determination of their levels were performed by high-performance liquid chromatography with photodiode array detector. Among 12 samples, 10 samples were found contaminated with pesticides. Chlorpyrifos was detected in four tested samples and concentrations ranged from 3.27 to 9.31 μg/l whereas fenitrothion ranging from (Below Detection Limit, <0.1 μg/l) to 33.41 μg/l in the tested samples. Parathion was found in two tested samples at the concentration of 0.73 and 6.23 μg/l. None of the tested samples was found contaminated with Methoxychlor, DDT and Ethion. Three soil bacterial isolates, Pseudomonas peli BG1, Burkholderia caryophylli BG4 and Brevundimonas diminuta PD6 degraded chlorpyrifos completely in 8, 10 and 10 days, respectively, when 20 mg/l chlorpyrifos was supplied as sole source of carbon. Whereas, BG1, BG4 and PD6 took 14, 16 and 16 days, respectively, for complete removal of 50 mg/l chlorpyrifos. Chlorpyrifos degradation rates were found maximum by all three isolates at 2nd day of incubation for both tested concentrations. The results of the present study suggest the need for regular monitoring of pesticide residues in water, to protect the aquatic environment. Chlorpyrifos degrading bacterial isolates can be used to clean up environmental samples contaminated with the organophosphate pesticides.

  3. European GEMAS mapping of agricultural soils: Arsenic results

    NASA Astrophysics Data System (ADS)

    Tarvainen, Timo; Reimann, Clemens; Albanese, Stefano; Birke, Manfred; Poňavič, Michal; Ladenberger, Anna

    2014-05-01

    The GEMAS data set provides a homogenised overview of arsenic distribution in agricultural (Ap horizon, 0-20 cm) and grazing land soil (Gr, 0-10 cm) of Europe. The GEMAS mapping project covers western Europe at a sample density of 1 site/2500 km2. Arsenic concentrations are reported for the

  4. Behavior of bensulfuron-methyl in an agricultural alkaline soil.

    PubMed

    Delgado-Moreno, L; Sánchez, L; Castillo, A; Pot, V; Peña, A

    2007-01-01

    A field experiment to determine the available bensulfuron-methyl (BSM) in the upper soil layer was conducted in an agricultural area in the South of Spain. To facilitate herbicide analysis, two application rates were employed, 200 g ha(-1) and 5 kg ha(-1). Samples of upper soil and soil solution were collected. Soil solution was sampled by means of metallic samplers, placed at a depth of 35 cm. In the plots receiving the lower dose ceramic suction, porous cups were also installed. Results from soil solution samples showed that the maximum BSM concentration was found after 8-10 days for the high irrigation supply (945 mm) and after 18-25 days for the lower irrigation regime (405 mm). The mathematical model FOCUSPELMO 1.1.1 was applied to interpret the data obtained in the field experiments. In general, there was a reasonable agreement between experimental and simulated data for soil samples, although the model did not acceptably predict herbicide concentrations in water soil samples. Ceramic cups sampled a higher soil water volume and more frequently than did the metallic samplers. However some variable results were attributed to preferential flow. PMID:17454376

  5. Soil biology and carbon in dryland agriculture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The goal of this paper is to explore potential management strategies in dryland agriculture that can promote soil health and crop productivity. Traditional crop production in the semiarid Great Plains consists of conventional tillage management of winter wheat (Triticum aestivum L.) - summer fallow....

  6. Transport of agricultural contaminants through karst soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Karst landscapes are common in many agricultural regions in the US. Well-developed karst landscapes are characterized by shallow soils, sinkholes, sinking streams, underground conduits, and springs. In these landscapes surface runoff is minimal and most recharge enters the subsurface relatively quic...

  7. The biogeochemical footprint of agricultural soil erosion

    NASA Astrophysics Data System (ADS)

    Govers, Gerard; Van Oost, Kristof; Wang, Zhengang

    2015-04-01

    Global biogeochemical cycles are a key component of the functioning of the Earth System: these cycles are all, to a varying extent, disturbed by human activities which not only has dramatic consequences for the global climate but also for the acidity of the world's oceans. It is only relatively recently that the role of lateral fluxes related to surface water movement and soil erosion and deposition (and the way those fluxes are modified by human action) is explicitly considered by the scientific community. In this paper we present an overview of our present-day understanding of the role of agricultural soil erosion in the global cycles of carbon, nitrogen, phosphorous and silica. We discuss the major processes through which erosion affects these global cycles and pay particular attention to the knowledge gaps that prevent us from accurately assessing the impact of soil erosion on global biogeochemical cycling at different temporal scales. Furthering our understanding (and better constraining our estimates) will require progress both in terms of model development and process understanding. Research needs can be most clearly identified with respect to soil organic carbon: (i) at present, large-scale soil erosion (and deposition) models are poorly constrained so that the amount of carbon mobilised by erosion (and its fate) cannot be accurately estimated and (ii) the fate of soil organic carbon buried by deposition or delivered to river network is poorly understood. Uncertainties for N, P and Si are larger than those for C as we have less information on the amount of these elements stored in agricultural soils and/or do not fully understand how these elements cycle through the soil/plant system. Agricultural soil erosion does not affect soil functioning through its effect on biogeochemical cycling. Erosion directly affects soil hydrological functioning and is likely to affect weathering processes and soil production. Addressing all these issues requires the

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

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

    residual (difference between calculated SOC by models and real SOC, analyzed in laboratory) as soil quality indices. We consider higher soil quality when the residuals are closer to cero or inside confidence intervals of the models (95%). As expected, the application of the models indicates that in all the treatments and the control plots (shrub on marls and shrub on limestone), the residuals are out of the confidence intervals for the models, showing a disequilibrium among soil properties because these treatments have been submitted to a perturbation such as the agricultural use. However, it can be observed that the residuals in the last sampling in control plots and some of the treatments, the least aggressive with the soil, are lower and therefore the soil it seems to the soil properties is achieving to their equilibrium among them. These soils are: Shrub on limestone and shrub on marls, Chipped pruned branches and Oat mulch non-plough. These results are in agreement with García-Orenes et al. (2010), who showed that the addition of oat straw to soil can be considered an effective soil management, because it produced an important increase of the different fractions of organic carbon and microbial activity, that it will be translated into a rapid improvement of soil quality. The application of the herbicides studied produced a decrease in all the soil parameters; these practices are not recommendable for a sustainable agricultural system in semiarid Mediterranean agro-ecosystem. -García-Orenes, F., Guerrero, C., Roldán, A., Mataix-Solera, J., Cerdà, A. Campoy, M., Zornoza, R., Bárcenas, G., Caravaca, F., (2010). Soil microbial biomass and activity under different agricultural management systems in a semiarid Mediterranean agroecosystem. Soil & Tillage Research 109: 110-115. -Zornoza, R., Mataix-Solera, J., Guerrero, C., Arcenegui, V., Mayoral, A.M., Morales, J. Mataix-Beneyto, J., 2007. Soil properties under natural forest in the Alicante Province of Spain. Geoderma

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

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

    residual (difference between calculated SOC by models and real SOC, analyzed in laboratory) as soil quality indices. We consider higher soil quality when the residuals are closer to cero or inside confidence intervals of the models (95%). As expected, the application of the models indicates that in all the treatments and the control plots (shrub on marls and shrub on limestone), the residuals are out of the confidence intervals for the models, showing a disequilibrium among soil properties because these treatments have been submitted to a perturbation such as the agricultural use. However, it can be observed that the residuals in the last sampling in control plots and some of the treatments, the least aggressive with the soil, are lower and therefore the soil it seems to the soil properties is achieving to their equilibrium among them. These soils are: Shrub on limestone and shrub on marls, Chipped pruned branches and Oat mulch non-plough. These results are in agreement with García-Orenes et al. (2010), who showed that the addition of oat straw to soil can be considered an effective soil management, because it produced an important increase of the different fractions of organic carbon and microbial activity, that it will be translated into a rapid improvement of soil quality. The application of the herbicides studied produced a decrease in all the soil parameters; these practices are not recommendable for a sustainable agricultural system in semiarid Mediterranean agro-ecosystem. -García-Orenes, F., Guerrero, C., Roldán, A., Mataix-Solera, J., Cerdà, A. Campoy, M., Zornoza, R., Bárcenas, G., Caravaca, F., (2010). Soil microbial biomass and activity under different agricultural management systems in a semiarid Mediterranean agroecosystem. Soil & Tillage Research 109: 110-115. -Zornoza, R., Mataix-Solera, J., Guerrero, C., Arcenegui, V., Mayoral, A.M., Morales, J. Mataix-Beneyto, J., 2007. Soil properties under natural forest in the Alicante Province of Spain. Geoderma

  10. Substantial dust loss of bioavailable phosphorus from agricultural soils

    PubMed Central

    Katra, Itzhak; Gross, Avner; Swet, Nitzan; Tanner, Smadar; Krasnov, Helena; Angert, Alon

    2016-01-01

    Phosphorus (P) is an essential element in terrestrial ecosystems. Knowledge on the role of dust in the biogeochemical cycling of phosphorus is very limited with no quantitative information on aeolian (by wind) P fluxes from soils. The aim of this study is to focus on P cycling via dust emissions under common land-use practices in an arid environment by integration of sample analyses and aeolian experiments. The experiments indicate significant P fluxes by PM10 dust due to agricultural land use. Even in a single wind-dust event at moderate velocity (7.0 m s−1), P flux in conventional agricultural fields can reach 1.83 kg km−2, that accumulates to a considerable amount per year at a regional scale. The results highlight a negative yearly balance in P content (up to hundreds kg km−2) in all agricultural soils, and thus more P nutrition is required to maintain efficient yield production. In grazing areas where no P nutrition is applied, the soil degradation process can lead to desertification. Emission of P from soil dust sources has significant implications for soil nutrient resources and management strategies in agricultural regions as well as for loading to the atmosphere and global biogeochemical cycles. PMID:27095629

  11. Substantial dust loss of bioavailable phosphorus from agricultural soils

    NASA Astrophysics Data System (ADS)

    Katra, Itzhak; Gross, Avner; Swet, Nitzan; Tanner, Smadar; Krasnov, Helena; Angert, Alon

    2016-04-01

    Phosphorus (P) is an essential element in terrestrial ecosystems. Knowledge on the role of dust in the biogeochemical cycling of phosphorus is very limited with no quantitative information on aeolian (by wind) P fluxes from soils. The aim of this study is to focus on P cycling via dust emissions under common land-use practices in an arid environment by integration of sample analyses and aeolian experiments. The experiments indicate significant P fluxes by PM10 dust due to agricultural land use. Even in a single wind-dust event at moderate velocity (7.0 m s‑1), P flux in conventional agricultural fields can reach 1.83 kg km‑2, that accumulates to a considerable amount per year at a regional scale. The results highlight a negative yearly balance in P content (up to hundreds kg km‑2) in all agricultural soils, and thus more P nutrition is required to maintain efficient yield production. In grazing areas where no P nutrition is applied, the soil degradation process can lead to desertification. Emission of P from soil dust sources has significant implications for soil nutrient resources and management strategies in agricultural regions as well as for loading to the atmosphere and global biogeochemical cycles.

  12. Curiosity analyzes Martian soil samples

    NASA Astrophysics Data System (ADS)

    Showstack, Randy; Balcerak, Ernie

    2012-12-01

    NASA's Mars Curiosity rover has conducted its first analysis of Martian soil samples using multiple instruments, the agency announced at a 3 December news briefing at the AGU Fall Meeting in San Francisco. "These results are an unprecedented look at the chemical diversity in the area," said NASA's Michael Meyer, program scientist for Curiosity.

  13. Properties of 21 Urban Agricultural Soils in Seoul, Korea

    NASA Astrophysics Data System (ADS)

    Kim, J.; Kim, H. S.; Kim, J. W.

    2012-04-01

    The number of urban agriculture practitioners has been increasing rapidly in Korea like many other urbanized countries recently. The Korean government enacted a law for promoting urban agriculture in 2011. However, urban soil environment can be potential sources of many toxic contaminants including heavy metals making people concern about the safety of the agricultural products from the urban agriculture. The accumulation of heavy metals in soil and plant by overuse of compost from animal waste was one of the raised concerns. This study was carried out to find out properties and total and phytoavailable (1.0 M NH4NO3 extractable) contents of heavy metals (Cd, Pb, Cu, Zn) in 21 urban agricultural soils in Seoul. On the average, the investigated urban soils showed pH1:5 6.89, EC1:5 0.14 dS m-1, organic mater 2.22%, available P2O5 139 mg kg-1, cation exchange capacity (CEC) 11.36 cmolc kg-1 and total nitrogen 0.15%. The average exchangeable-Ca, -Mg, -K and -Na of the 21 samples were 6.71, 1.44, 1.06 and 0.30 cmol+ kg-1, respectively. Total heavy metal concentrations (Cd 0.97-3.17 mg kg-1, average 1.89 mg kg-1; Pb 8.10-46.27 mg kg-1, average 19.96 mg kg-1; Cu 8.97-133.40 mg kg-1, average 38.37 mg kg-1; and Zn 38.97-180.06 mg kg-1, average 97.73 mg kg-1) in urban agricultural soils were lower than those of the warning standard in the area 1 according to the Soil Environmental Conservation Act of Korea. Phytoavailable-Cu, -Pb, and -Zn concentrations of the samples showed 0.02-0.28, N.D-0.09 and 0.01-0.43 mg kg-1, respectively. Phytoavailable-Cd was not detected. The average phytoavailable-Cu concentration from this study was similar to that from the previous phytoavailable-Cu of the highly contaminated soils from nearby abandoned mines, which might be resulted from overuse of compost from animal waste. Results showed a necessity of long-term monitoring of soils for sustainable urban agriculture in Korea.

  14. Organochlorine insecticide residues in soils and soil invertebrates from agricultural lands

    USGS Publications Warehouse

    Gish, C.D.

    1970-01-01

    Soils and earthworms and other soil invertebrates were collected from 67 agricultural fields in eight States. Samples were analyzed by gas chromatography for DDE, DDD, DDT, aldrin, dieldrin, endrin, heptachlor, heptachlor epoxide, and gamma-chlordane insecticides. Organochlorine insecticides in soils averaged 1.5 ppm, dry weight, and in earthworms, 13.8 ppm. Residues in earthworms averaged nine times that in soils. Residues ranged from a trace to 19.1 ppm in soils and from a trace to 159.4 ppm in earthworms. Residues in beetle larvae from two fields averaged 0.6 ppm; in snails from two fields, 3.5 ppm; and in slugs from four fields, 89.0 ppm. Amounts of insecticides in earthworms varied directly with amounts in soils. Coefficients of correlation between residues in soils and residues in earthworms usually were significant for DDE, DDD, and DDT regardless of crop or soil type.

  15. Agricultural plants and soil as a reservoir for Pseudomonas aeruginosa.

    PubMed

    Green, S K; Schroth, M N; Cho, J J; Kominos, S K; Vitanza-jack, V B

    1974-12-01

    Pseudomonas aeruginosa was detected in 24% of the soil samples but in only 0.13% of the vegetable samples from various agricultural areas of California. The distribution of pyocin types of soil and vegetable isolates was similar to that of clinical strains, and three of the soil isolates were resistant to carbenicillin. Pseudomonas aeruginosa multiplied in lettuce and bean under conditions of high temperature and high relative humidity (27 C and 80-95% relative humidity) but declined when the temperature and humidity were lowered (16 C, 55-75% relative humidity). The results suggest that soil is a reservior for P. aeruginosa and that the bacterium has the capacity to colonize plants during favorable conditions of temperature and moisture. PMID:4217591

  16. Root Induced Heterogeneity In Agricultural Soils

    NASA Astrophysics Data System (ADS)

    Gomes, C.; Gabai, R.; Weisbrod, N.; Furman, A.

    2012-12-01

    In this study we investigate the role of plant induced heterogeneity on water dynamics in agricultural soils. We conducted three experiments in two sites (one still ongoing) in which a trench was excavated in the root zone of an orchard and the subsurface, to a depth of over 1 m, was instrumented in high resolution with water content, water potential and temperature sensors. High temporal resolution monitoring of soil state was carried for over a year, period that included natural (Mediterranean) climate boundary forcing. In addition, sprinkler, flood, and spray irrigation boundary conditions were forced for short time periods to explore the infiltration process under these conditions. One site was an Avocado orchard planted in red sandy soil while the other, still on-going, is in a grape vineyards irrigated by tap and treated wastewater, planted over alluvial clayey soil. In the vineyard, we are comparing soil irrigated with fresh water to soil irrigated with treated waste water for more than 10 years. Our preliminary results indicate several interesting phenomena. First, the role of plant roots is clearly seen as the major roots act as a conduit for water (and solute), providing a fast bypass of the upper soil. Further, we identified different regions of the subsurface that apparently were of the same texture, but in practice presented very different hydraulic properties. Second, the role of these roots depends on the boundary conditions. That is, the root bypass acts differently when soil is flooded than when flow is strictly unsaturated. As expected, simulation of the experimental results show good fit only if the domain heterogeneity of soil properties was incorporated. Results for the clayey soils were not available at time of abstract submission.

  17. Soil strength and macropore volume limit root elongation rates in many UK agricultural soils

    PubMed Central

    Valentine, Tracy A.; Hallett, Paul D.; Binnie, Kirsty; Young, Mark W.; Squire, Geoffrey R.; Hawes, Cathy; Bengough, A. Glyn

    2012-01-01

    Background and Aims Simple indicators of crop and cultivar performance across a range of soil types and management are needed for designing and testing sustainable cropping practices. This paper determined the extent to which soil chemical and physical properties, particularly soil strength and pore-size distribution influences root elongation in a wide range of agricultural top soils, using a seedling-based indicator. Methods Intact soil cores were sampled from the topsoil of 59 agricultural fields in Scotland, representing a wide geographic spread, range of textures and management practices. Water release characteristics, dry bulk density and needle penetrometer resistance were measured on three cores from each field. Soil samples from the same locations were sieved, analysed for chemical characteristics, and packed to dry bulk density of 1·0 g cm−3 to minimize physical constraints. Root elongation rates were determined for barley seedlings planted in both intact field and packed soil cores at a water content close to field capacity (–20 kPa matric potential). Key Results Root elongation in field soil was typically less than half of that in packed soils. Penetrometer resistance was typically between 1 and 3 MPa for field soils, indicating the soils were relatively hard, despite their moderately wet condition (compared with <0·2 MPa for packed soil). Root elongation was strongly linked to differences in physical rather than chemical properties. In field soil root elongation was related most closely to the volume of soil pores between 60 µm and 300 µm equivalent diameter, as estimated from water-release characteristics, accounting for 65·7 % of the variation in the elongation rates. Conclusions Root elongation rate in the majority of field soils was slower than half of the unimpeded (packed) rate. Such major reductions in root elongation rates will decrease rooting volumes and limit crop growth in soils where nutrients and water are scarce. PMID:22684682

  18. Grass mulching effect on infiltration, surface runoff and soil loss of three agricultural soils in Nigeria.

    PubMed

    Adekalu, K O; Olorunfemi, I A; Osunbitan, J A

    2007-03-01

    Mulching the soil surface with a layer of plant residue is an effective method of conserving water and soil because it reduces surface runoff, increases infiltration of water into the soil and retard soil erosion. The effectiveness of using elephant grass (Pennisetum purpureum) as mulching material was evaluated in the laboratory using a rainfall simulator set at rainfall intensities typical of the tropics. Six soil samples, two from each of the three major soil series representing the main agricultural soils in South Western Nigeria were collected, placed on three different slopes, and mulched with different rates of the grass. The surface runoff, soil loss, and apparent cumulative infiltration were then measured under each condition. The results with elephant grass compared favorably with results from previous experiments using rice straw. Runoff and soil loss decreased with the amount of mulch used and increased with slope. Surface runoff, infiltration and soil loss had high correlations (R = 0.90, 0.89, and 0.86, respectively) with slope and mulch cover using surface response analysis. The mean surface runoff was correlated negatively with sand content, while mean soil loss was correlated positively with colloidal content (clay and organic matter) of the soil. Infiltration was increased and soil loss was reduced greatly with the highest cover. Mulching the soils with elephant grass residue may benefit late cropping (second cropping) by increasing stored soil water for use during dry weather and help to reduce erosion on sloping land.

  19. Genotoxicity of agricultural soils in the vicinity of industrial area.

    PubMed

    Ansari, Mohd Ikram; Malik, Abdul

    2009-03-17

    Soil samples from agricultural fields (cultivated) in the vicinity of industrial area of Ghaziabad City (India) were collected. In this city, wastewater coming from both industrial and domestic sources and without any treatment is used to irrigate the food crops. This practice has been polluting the soil and pollutants might reach the food chain. Gas chromatographic analysis show the presence of certain organochlorine (DDE, DDT, dieldrin, aldrin and endosulfan) and organophosphorus (dimethoate, malathion, methylparathion and chlorpyrifos) pesticides in soil samples. Samples were extracted using different solvents, i.e. methanol, chloroform, acetonitrile, hexane and acetone (all were HPLC-grade, SRL, India), and the extracts were assayed for genotoxic potential using Ames Salmonella/microsome test, DNA repair defective mutants and bacteriophage lambda systems. TA98 and TA100 were found to be the most sensitive strains to all the soil extracts tested. Methanol extracts exhibited a maximum mutagenicity with TA98 strain {540 (-S9) and 638 (+S9) revertants/g of soil} and 938 (-S9) and 1008 (+S9) revertants/g of soil with TA100 strain. The damage in the DNA repair defective mutants was found maximum with methanolic extract followed by acetonitrile, chloroform, hexane and acetone at the dose level of 40 microl/ml culture after 6h of treatment. The survival was 25, 30, 32, 33 and 35% in polA strain after 6h of treatment when tested with wastewater irrigated soil extracts of methanol, acetonitrile, chloroform, hexane and acetone, respectively. A significant decrease in the plaque forming units of bacteriophage lambda was also observed when treated with 40 microl of test samples. Present results showed that methanolic extracts of soil were more toxic than other soil extracts. The soil is accumulating a large number of pollutants due to wastewater irrigation and this practice of accumulation has an impact on soil health.

  20. Soil sampling kit and a method of sampling therewith

    DOEpatents

    Thompson, C.V.

    1991-02-05

    A soil sampling device and a sample containment device for containing a soil sample is disclosed. In addition, a method for taking a soil sample using the soil sampling device and soil sample containment device to minimize the loss of any volatile organic compounds contained in the soil sample prior to analysis is disclosed. The soil sampling device comprises two close fitting, longitudinal tubular members of suitable length, the inner tube having the outward end closed. With the inner closed tube withdrawn a selected distance, the outer tube can be inserted into the ground or other similar soft material to withdraw a sample of material for examination. The inner closed end tube controls the volume of the sample taken and also serves to eject the sample. The soil sample containment device has a sealing member which is adapted to attach to an analytical apparatus which analyzes the volatile organic compounds contained in the sample. The soil sampling device in combination with the soil sample containment device allows an operator to obtain a soil sample containing volatile organic compounds and minimizing the loss of the volatile organic compounds prior to analysis of the soil sample for the volatile organic compounds. 11 figures.

  1. Soil sampling kit and a method of sampling therewith

    DOEpatents

    Thompson, Cyril V.

    1991-01-01

    A soil sampling device and a sample containment device for containing a soil sample is disclosed. In addition, a method for taking a soil sample using the soil sampling device and soil sample containment device to minimize the loss of any volatile organic compounds contained in the soil sample prior to analysis is disclosed. The soil sampling device comprises two close fitting, longitudinal tubular members of suitable length, the inner tube having the outward end closed. With the inner closed tube withdrawn a selected distance, the outer tube can be inserted into the ground or other similar soft material to withdraw a sample of material for examination. The inner closed end tube controls the volume of the sample taken and also serves to eject the sample. The soil sample containment device has a sealing member which is adapted to attach to an analytical apparatus which analyzes the volatile organic compounds contained in the sample. The soil sampling device in combination with the soil sample containment device allow an operator to obtain a soil sample containing volatile organic compounds and minimizing the loss of the volatile organic compounds prior to analysis of the soil sample for the volatile organic compounds.

  2. GEMAS: Unmixing magnetic properties of European agricultural soil

    NASA Astrophysics Data System (ADS)

    Fabian, Karl; Reimann, Clemens; Kuzina, Dilyara; Kosareva, Lina; Fattakhova, Leysan; Nurgaliev, Danis

    2016-04-01

    High resolution magnetic measurements provide new methods for world-wide characterization and monitoring of agricultural soil which is essential for quantifying geologic and human impact on the critical zone environment and consequences of climatic change, for planning economic and ecological land use, and for forensic applications. Hysteresis measurements of all Ap samples from the GEMAS survey yield a comprehensive overview of mineral magnetic properties in European agricultural soil on a continental scale. Low (460 Hz), and high frequency (4600 Hz) magnetic susceptibility k were measured using a Bartington MS2B sensor. Hysteresis properties were determined by a J-coercivity spectrometer, built at the paleomagnetic laboratory of Kazan University, providing for each sample a modified hysteresis loop, backfield curve, acquisition curve of isothermal remanent magnetization, and a viscous IRM decay spectrum. Each measurement set is obtained in a single run from zero field up to 1.5 T and back to -1.5 T. The resulting data are used to create the first continental-scale maps of magnetic soil parameters. Because the GEMAS geochemical atlas contains a comprehensive set of geochemical data for the same soil samples, the new data can be used to map magnetic parameters in relation to chemical and geological parameters. The data set also provides a unique opportunity to analyze the magnetic mineral fraction of the soil samples by unmixing their IRM acquisition curves. The endmember coefficients are interpreted by linear inversion for other magnetic, physical and chemical properties which results in an unprecedented and detailed view of the mineral magnetic composition of European agricultural soils.

  3. 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.

  4. Changes in soil fungal communities across a landscape of agricultural soil land-uses

    NASA Astrophysics Data System (ADS)

    Berthrong, S. T.; Buckley, D. H.; Drinkwater, L. E.

    2012-12-01

    Agricultural management is a major driver of changes in soils and their resident microbial communities, but we do not yet have a clear picture of how agriculture affects soil fungi. This is an important gap in our knowledge since fungi play an important role in many soil processes. Previous research has suggested that organic management practices can lead to an increase in soil fungal community diversity, which could have impacts on soil processes and alter the long term trajectory of soil quality in agricultural systems. Also, the relationship between management effects, biogeography, and soil fungi is not clear. The biogeography of macroscopic species is well described by taxa-area relationships and distance decay models, and recent research has suggested that certain subsets of fungi (e.g. AMF, litter sapotrophs) demonstrate similar patterns. However there is little information on how soil fungi as a whole are distributed across a landscape with soils under different managements. The goal of this project was to examine how different management practices alter soil fungal communities across a landscape of agricultural fields in upstate NY. We asked several specific questions: 1) Do different types of agricultural land-uses lead to divergent or convergent communities of soil fungi? 2) If soil type is held constant, do soil fungal communities diverge with geographic distance? 3) What are the major fungal groups that change in response to soil management, and are they cosmopolitan or endemic across the landscape? We studied these questions across agricultural fields in upstate NY that ranged from conventional corn, organic grains/corn, and long-term pasture. We sampled four fields (conventional, 10 and 20 year organic, and pasture) that had identical soils types and ranged from 100 m to 4 km apart. We utilized a multiplexed pyrosequencing approach on genomic DNA to analyze the structure of the soils' fungal communities. This approach allowed us to study soil fungi

  5. Microbial Community Structure and Enzyme Activities in Semiarid Agricultural Soils

    NASA Astrophysics Data System (ADS)

    Acosta-Martinez, V. A.; Zobeck, T. M.; Gill, T. E.; Kennedy, A. C.

    2002-12-01

    The effect of agricultural management practices on the microbial community structure and enzyme activities of semiarid soils of different textures in the Southern High Plains of Texas were investigated. The soils (sandy clay loam, fine sandy loam and loam) were under continuous cotton (Gossypium hirsutum L.) or in rotations with peanut (Arachis hypogaea L.), sorghum (Sorghum bicolor L.) or wheat (Triticum aestivum L.), and had different water management (irrigated or dryland) and tillage (conservation or conventional). Microbial community structure was investigated using fatty acid methyl ester (FAME) analysis by gas chromatography and enzyme activities, involved in C, N, P and S cycling of soils, were measured (mg product released per kg soil per h). The activities of b-glucosidase, b-glucosaminidase, alkaline phosphatase, and arylsulfatase were significantly (P<0.05) increased in soils under cotton rotated with sorghum or wheat, and due to conservation tillage in comparison to continuous cotton under conventional tillage. Principal component analysis showed FAME profiles of these soils separated distinctly along PC1 (20 %) and PC2 (13 %) due to their differences in soil texture and management. No significant differences were detected in FAME profiles due to management practices for the same soils in this sampling period. Enzyme activities provide early indications of the benefits in microbial populations and activities and soil organic matter under crop rotations and conservation tillage in comparison to the typical practices in semiarid regions of continuous cotton and conventional tillage.

  6. Soil microbial communities as suitable bioindicators of trace metal pollution in agricultural volcanic soils

    NASA Astrophysics Data System (ADS)

    Parelho, Carolina; dos Santos Rodrigues, Armindo; do Carmo Barreto, Maria; Gonçalo Ferreira, Nuno; Garcia, Patrícia

    2015-04-01

    soil sample and quantified spectrophotometrically using a Nanodrop ND-1000. Analysis of variance (ANOVA) was carried out in order to evaluate the significant differences in SMCs activity between all soil matrices. To associate the SMCs responses to the tracers of distinct agricultural farming systems, data were further explored under Principal Component Analysis (PCA). Biomarkers responses were combined into a stress index (IBR), described by Beliaeff & Burgeot (2002). Results/Discussion: All SMCs parameters displayed significant differences between agricultural soils and reference soils, except for metabolic quotient and RNA to DNA ratio (p<0.05), revealing that SMCs are suitable bioindicators of agricultural soil quality in volcanic soils. No significant differences were found for the soil basal respiration and acid phosphatase among the farming systems, suggesting that soils amendments (a cross farming practice) are a stressing factor disrupting local SMCs activities. The PCA analysis revealed that lithium is the priority metal affecting the SMCs responses in conventional farming systems. The IBR values indicated that soils ecosystem health between farming systems are ranked as: organic (4.96) > traditional (12.94) > conventional (17.28) (the higher the value, the worse the soil health status). Conclusion: Results support the soil microbial toolbox as suitable bioindicators of metal pollution in agricultural volcanic soils, highlighting the importance of integrated biomarker-based strategies for the development of the "Trace Metal Footprint" in Andosols.

  7. Uranium, Thorium and Potassium concentrations in agricultural and grazing land soils of Europe

    NASA Astrophysics Data System (ADS)

    De Vivo, Benedetto; Cicchella, Domenico; Albanese, Stefano; Birke, Manfred; Demetriades, Alecos; De Vos, Walter; Dinelli, Enrico; Lima, Annamaria; O'Connor, Patrick J.; Salpeteur, Ignace; Tarvainen, Timo

    2014-05-01

    Two thousand two hundred and eighteen samples of agricultural soil and 2127 samples of grazing land soil were collected with an average sampling density of 1 site per 2500 km2 over an area of 5.6 million km2 across Europe. The uranium concentrations over the survey area vary from <0.1 to 23.55 mg/kg in agricultural soil and from <0.1 to 73.32 mg/kg in grazing land soil, with a median value of 0.77 and 0.74, respectively. The median Th content is 2.89 mg/kg in agricultural soil and 2.5 mg/kg in grazing land soil; the range varies from <0.1 to 63.1 mg/kg in agricultural soil and <0.1 to 55.64 mg/kg in grazing land soil. The median potassium content is 16 000 mg/kg in agricultural soil and 14 900 mg/kg in grazing land soil, with a range between 241 mg/kg and 79,200 mg/kg in agricultural soil and between 241 mg/kg and 50000 mg/kg in grazing land soil. The new data define the soil geochemical U, Th and K background for European agricultural and grazing land soil, providing information of crucial importance to increase our knowledge about 'soil quality' at the European scale. Such data are essential for agriculture, animal and human health, setting of environmental standards, water quality, land use planning and the identification of mineral resource potential.

  8. Ice Nucleation Activity of Various Agricultural Soil Dust Aerosol Particles

    NASA Astrophysics Data System (ADS)

    Schiebel, Thea; Höhler, Kristina; Funk, Roger; Hill, Thomas C. J.; Levin, Ezra J. T.; Nadolny, Jens; Steinke, Isabelle; Suski, Kaitlyn J.; Ullrich, Romy; Wagner, Robert; Weber, Ines; DeMott, Paul J.; Möhler, Ottmar

    2016-04-01

    Recent investigations at the cloud simulation chamber AIDA (Aerosol Interactions and Dynamics in the Atmosphere) suggest that agricultural soil dust has an ice nucleation ability that is enhanced up to a factor of 10 compared to desert dust, especially at temperatures above -26 °C (Steinke et al., in preparation for submission). This enhancement might be caused by the contribution of very ice-active biological particles. In addition, soil dust aerosol particles often contain a considerably higher amount of organic matter compared to desert dust particles. To test agricultural soil dust as a source of ice nucleating particles, especially for ice formation in warm clouds, we conducted a series of laboratory measurements with different soil dust samples to extend the existing AIDA dataset. The AIDA has a volume of 84 m3 and operates under atmospherically relevant conditions over wide ranges of temperature, pressure and humidity. By controlled adiabatic expansions, the ascent of an air parcel in the troposphere can be simulated. As a supplement to the AIDA facility, we use the INKA (Ice Nucleation Instrument of the KArlsruhe Institute of Technology) continuous flow diffusion chamber based on the design by Rogers (1988) to expose the sampled aerosol particles to a continuously increasing saturation ratio by keeping the aerosol temperature constant. For our experiments, soil dust was dry dispersed into the AIDA vessel. First, fast saturation ratio scans at different temperatures were performed with INKA, sampling soil dust aerosol particles directly from the AIDA vessel. Then, we conducted the AIDA expansion experiment starting at a preset temperature. The combination of these two different methods provides a robust data set on the temperature-dependent ice activity of various agriculture soil dust aerosol particles with a special focus on relatively high temperatures. In addition, to extend the data set, we investigated the role of biological and organic matter in more

  9. Soil macronutrient sensing for precision agriculture.

    PubMed

    Kim, Hak-Jin; Sudduth, Kenneth A; Hummel, John W

    2009-10-01

    Accurate measurements of soil macronutrients (i.e., nitrogen, phosphorus, and potassium) are needed for efficient agricultural production, including site-specific crop management (SSCM), where fertilizer nutrient application rates are adjusted spatially based on local requirements. Rapid, non-destructive quantification of soil properties, including nutrient levels, has been possible with optical diffuse reflectance sensing. Another approach, electrochemical sensing based on ion-selective electrodes or ion-selective field effect transistors, has been recognized as useful in real-time analysis because of its simplicity, portability, rapid response, and ability to directly measure the analyte with a wide range of sensitivity. Current sensor developments and related technologies that are applicable to the measurement of soil macronutrients for SSCM are comprehensively reviewed. Examples of optical and electrochemical sensors applied in soil analyses are given, while advantages and obstacles to their adoption are discussed. It is proposed that on-the-go vehicle-based sensing systems have potential for efficiently and rapidly characterizing variability of soil macronutrients within a field.

  10. Effect of land management on soil microbial properties in agricultural terraces of Eastern Spain

    NASA Astrophysics Data System (ADS)

    Morugán-Coronado, Alicia; Cerdà, Artemi; Garcia-Orenes, Fuensanta

    2014-05-01

    Soil quality is important for the sustainable development of terrestrial ecosystems. Agricultural land management is one of most important anthropogenic activities that greatly alters soil characteristics, including physical, chemical, and microbiological properties. The unsuitable land management can lead to a soil fertility loss and to a reduction in the abundance and diversity of soil microorganisms. However, ecological practices and some organic amendments can promote the activities of soil microbial communities, and increase its biodiversity. The microbial soil communities are the most sensitive and rapid indicators of perturbations in land use and soil enzyme activities are sensitive biological indicators of the effects of soil management practices. In this study, a field experiment was performed at clay-loam agricultural soil with an orchard of orange trees in Alcoleja (eastern Spain) to assess the long-term effects of inorganic fertilizers (F), intensive ploughing (P) and sustainable agriculture (S) on the soil microbial biomass carbon (Cmic), enzyme activities (Urease, ß-glucosidase and phosphatase), basal soil repiration (BSR) and the relationship between them, and soil fertility in agro-ecosystems of Spain. Nine soil samples were taken from each agricultural management plot. In all the samples were determined the basal soil respiration, soil microbial biomass carbon, water holding capacity, electrical conductivity, soil organic carbon, nitrogen, available phosphorus, aggregate stability, cation exchange capacity, phosphorous, pH, texture, carbonates, active limestone and as enzimatic activities: Urease, ß-glucosidase and phosphatase. The results showed a substantial level of differentiation in the microbial properties, in terms of management practices, which was highly associated with soil organic matter content. The most marked variation in the different parameters studied appears to be related to sustainable agriculture terrace. The management

  11. REPRESENTATIVE SAMPLING AND ANALYSIS OF HETEROGENEOUS SOILS

    EPA Science Inventory

    Standard sampling and analysis methods for hazardous substances in contaminated soils currently are available and routinely employed. Standard methods inherently assume a homogeneous soil matrix and contaminant distribution; therefore only small sample quantities typically are p...

  12. Combining agricultural practices key to elevating soil microbial activities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The concept of soil health is an emerging topic in applied ecology, specifically as it pertains to the agriculture, which utilizes approximately 40% of earth’s land. However, rigorous quantification of soil health and the services provided by soil organisms to support agriculture production (e.g., n...

  13. Remote sensing of agricultural crops and soils

    NASA Technical Reports Server (NTRS)

    Bauer, M. E. (Principal Investigator)

    1982-01-01

    Research results and accomplishments of sixteen tasks in the following areas are described: (1) corn and soybean scene radiation research; (2) soil moisture research; (3) sampling and aggregation research; (4) pattern recognition and image registration research; and (5) computer and data base services.

  14. Terraced agriculture protects soil from erosion: Case studies in Madagascar

    NASA Astrophysics Data System (ADS)

    Rabesiranana, Naivo; Rasolonirina, Martin; Fanantenansoa Solonjara, Asivelo; Nomenjanahary Ravoson, Heritiana; Mabit, Lionel

    2016-04-01

    - Soil degradation is a major concern in Madagascar but quantitative information is not widely available. Due to its impact on the sustainability of agricultural production, there is a clear need to acquire data on the extent and magnitude of soil erosion/sedimentation under various agricultural practices in order to promote effective conservation strategies. Caesium-137 and 210Pbex fallout radionuclides (FRNs) possess particular characteristics that make them effective soil tracers for erosion studies. After fallout, 137Cs and 210Pbex are rapidly adsorbed onto fine soil particles. But to date, combined use of these FRNs has never been used to document soil erosion in Madagascar. The study area is located 40 km east of Antananarivo, in Madagascar highlands. Two adjacent cultivated fields have been selected (i.e. a sloped field and a terraced field) as well as an undisturbed reference site in the vicinity of these agricultural fields. Soil samples were collected along downslope transects using motorized corer. The 137Cs and 210Pb gamma analysis were performed at the Institut National des Sciences et Techniques Nucléaires (INSTN-Madagascar) using a high resolution and low background N-type HPGe detector. Results showed that at the terraced field, 137Cs and 210Pbex inventories reached 145 Bq/m2 to 280 Bq/m2 and 2141 Bq/m2 to 4253 Bq/m2, respectively. At the sloped field, the 137Cs and 210Pbex inventories values ranged from 110 Bq/m2 to 280 Bq/m2 and from 2026 Bq/m2 to 4110 Bq/m2, respectively. The net soil erosion determined for the sloped field were 9.6 t/ha/y and 7.2 t/ha/y for 137Cs and 210Pbex methods, respectively. In contrast, at the terraced field, the net soil erosion rates reached only 3.4 t/ha/y and 3.8 t/ha/y, respectively. The preliminary results of this research highlighted that terraced agricultural practice provides an efficient solution to protect soil resources of the Malagasy highlands.

  15. Hyperspectral mapping of crop and soils for precision agriculture

    NASA Astrophysics Data System (ADS)

    Whiting, Michael L.; Ustin, Susan L.; Zarco-Tejada, Pablo; Palacios-Orueta, Alicia; Vanderbilt, Vern C.

    2006-08-01

    Precision agriculture requires high spectral and spatial resolution imagery for advanced analyses of crop and soil conditions to increase environmental protection and producers' sustainability. GIS models that anticipate crop responses to nutrients, water, and pesticides require high spatial detail to generate application prescription maps. While the added precision of geo-spatial interpolation to field scouting generates improved zone maps and are an improvement over field-wide applications, it is limited in detail due to expense, and lacks the high precision required for pixel level applications. Multi-spectral imagery gives the spatial detail required, but broad band indexes are not sensitive to many variables in the crop and soil environment. Hyperspectral imagery provides both the spatial detail of airborne imagery and spectral resolution for spectroscopic and narrow band analysis techniques developed over recent decades in the laboratory that will advance precise determination of water and bio-physical properties of crops and soils. For several years, we have conducted remote sensing investigations to improve cotton production through field spectrometer measurements, and plant and soil samples in commercial fields and crop trials. We have developed spectral analyses techniques for plant and soil conditions through determination of crop water status, effectiveness of pre-harvest defoliant applications, and soil characterizations. We present the most promising of these spectroscopic absorption and narrow band index techniques, and their application to airborne hyperspectral imagery in mapping the variability in crops and soils.

  16. Biological and biochemical soil indicators: monitoring tools of different agricultural managements

    NASA Astrophysics Data System (ADS)

    Scotti, Riccardo; Sultana, Salma; Scelza, Rosalia; Marzaioli, Rossana; D'Ascoli, Rosaria; Rao, Maria A.

    2010-05-01

    The intensive agricultural managements, increased in the last twenty years, have resulted in a decrease in fertility of soils, representing a serious threat to agricultural productivity due to both the increase in production cost, mainly for intensive use of mineral fertilizers, and the loss of the quality of crops themselves. Organic matter content is closely related to the soil fertility and its progressive reduction in cultivates soils, without a satisfactory recovery, could make agriculture untenable, resulting in a high detrimental effect on environment. But an appropriate soil management practices can improve soil quality by utilizing organic amendments as alternative to mineral fertilizers to increase soil quality and plant growth. In this context, demand of suitable indicators, whose are able to assess the impact of different agricultural managements on soil quality, has increased. It has shown that soil biological and biochemical properties are able to respond to small changes in soil conditions, thus providing information on subtle alterations in soil quality. Aim of this study was to evaluate the use of soil biological and biochemical properties as fertility indicators in agricultural soils under different agricultural managements, sited in Campania Region (Southern Italy). After a preliminary monitoring phase of soil fertility on different farms sited in five agricultural areas of Campania Region, we have selected two farms in two different study areas to assess the effect on soil quality of different organic amendments. In particular, a compost from municipal solid waste and wood from scraps of poplars pruning were supplied in different doses and ratios. Soil samplings after one month from the amendment addition and then every 4 months until a year were carried out. All collected soil samples were characterized by main physical, chemical, biochemical and biological properties. In general, the use of different organic amendments showed a positive effect

  17. Sampling network stratification by terrain classification in eroded agricultural landscapes at plot scale

    NASA Astrophysics Data System (ADS)

    Penížek, Vít; Zádorová, Tereza; Kodešová, Radka

    2015-04-01

    The description of soil properties variability is important aspect in land management and food production at plot scale. We describe novelty approach for design of sampling network on agricultural plots with high relief variability. The terrain properties were used for improved spatial prediction of soil properties including design of the sampling network. Regular sampling network, random sampling network, systematic unaligned sampling network and stratified sampling network schemes were compared to prove the advantages of relief based stratified sampling networks. The study was performed for humus horizon depth prediction on agriculture plot of 6.5 ha with dissected relief where originally homogenous soil cover was differentiated by erosion and sedimentation into mosaic of Chernozem, Regosol and colluvial soils. Moreover the comparison was done on three levels of sampling density (65, 40 and 24 sampling points). The stratification of sampling network was based on unsupervised relief classification. The performance of the soil properties prediction based on different sampling network was assesed by RMSE calculation based on predicted values versus validation dataset. According the RMSE, the stratified sampling network performed the best (7.4 cm) comparing the regular sampling network (10.8 cm), random sampling network (17.7 cm) and systematic unaligned sampling network (11.2 cm). The accuracy of the soil properties spatial prediction decreased with the decreasing number of sampling points, but the stratified network performed significantly better that other used methods. The study showed that, for soil properties spatial variability description at certain accuracy level, relief-based stratified network can contain 25 % less sampling points comparing to regular network. This leads to potential financial and person cost reduction for the soil survey. The study was supported by grant nr. 13-07516P of the Czech science foundation and by grant nr. QJ1230319 of the

  18. Characterization of Soil Samples of Enzyme Activity

    ERIC Educational Resources Information Center

    Freeland, P. W.

    1977-01-01

    Described are nine enzyme essays for distinguishing soil samples. Colorimetric methods are used to compare enzyme levels in soils from different sites. Each soil tested had its own spectrum of activity. Attention is drawn to applications of this technique in forensic science and in studies of soil fertility. (Author/AJ)

  19. A soil sampling intercomparison exercise for the ALMERA network.

    PubMed

    Belli, Maria; de Zorzi, Paolo; Sansone, Umberto; Shakhashiro, Abduhlghani; Gondin da Fonseca, Adelaide; Trinkl, Alexander; Benesch, Thomas

    2009-11-01

    Soil sampling and analysis for radionuclides after an accidental or routine release is a key factor for the dose calculation to members of the public, and for the establishment of possible countermeasures. The IAEA organized for selected laboratories of the ALMERA (Analytical Laboratories for the Measurement of Environmental Radioactivity) network a Soil Sampling Intercomparison Exercise (IAEA/SIE/01) with the objective of comparing soil sampling procedures used by different laboratories. The ALMERA network is a world-wide network of analytical laboratories located in IAEA member states capable of providing reliable and timely analysis of environmental samples in the event of an accidental or intentional release of radioactivity. Ten ALMERA laboratories were selected to participate in the sampling exercise. The soil sampling intercomparison exercise took place in November 2005 in an agricultural area qualified as a "reference site", aimed at assessing the uncertainties associated with soil sampling in agricultural, semi-natural, urban and contaminated environments and suitable for performing sampling intercomparison. In this paper, the laboratories sampling performance were evaluated.

  20. Environmental Fate of Double-Stranded RNA in Agricultural Soils

    PubMed Central

    Dubelman, Samuel; Fischer, Joshua; Zapata, Fatima; Huizinga, Kristin; Jiang, Changjian; Uffman, Joshua; Levine, Steven; Carson, David

    2014-01-01

    A laboratory soil degradation study was conducted to determine the biodegradation potential of a DvSnf7 dsRNA transcript derived from a Monsanto genetically modified (GM) maize product that confers resistance to corn rootworm (CRW; Diabrotica spp.). This study provides new information to improve the environmental assessment of dsRNAs that become pesticidal through an RNAi process. Three agricultural soils differing in their physicochemical characteristics were obtained from the U.S., Illinois (IL; silt loam), Missouri (MO; loamy sand) and North Dakota (ND; clay loam), and exposed to the target dsRNA by incorporating insect-protected maize biomass and purified (in vitro-transcribed) DvSnf7 RNA into soil. The GM and control (non-GM maize) materials were added to each soil and incubated at ca. 22°C for 48 hours (h). Samples were collected at 12 time intervals during the incubation period, extracted, and analyzed using QuantiGene molecular analysis and insect bioassay methods. The DT50 (half-life) values for DvSnf7 RNA in IL, MO, and ND soils were 19, 28, and 15 h based on QuantiGene, and 18, 29, and 14 h based on insect bioassay, respectively. Furthermore, the DT90 (time to 90% degradation) values for DvSnf7 RNA in all three soils were <35 h. These results indicate that DvSnf7 RNA was degraded and biological activity was undetectable within approximately 2 days after application to soil, regardless of texture, pH, clay content and other soil differences. Furthermore, soil-incorporated DvSnf7 RNA was non-detectable in soil after 48 h, as measured by QuantiGene, at levels ranging more than two orders of magnitude (0.3, 1.5, 7.5 and 37.5 µg RNA/g soil). Results from this study indicate that the DvSnf7 dsRNA is unlikely to persist or accumulate in the environment. Furthermore, the rapid degradation of DvSnf7 dsRNA provides a basis to define relevant exposure scenarios for future RNA-based agricultural products. PMID:24676387

  1. Burkholderia cordobensis sp. nov., from agricultural soils.

    PubMed

    Draghi, Walter O; Peeters, Charlotte; Cnockaert, Margo; Snauwaert, Cindy; Wall, Luis G; Zorreguieta, Angeles; Vandamme, Peter

    2014-06-01

    Two Gram-negative, rod-shaped bacteria were isolated from agricultural soils in Córdoba province in central Argentina. Their 16S rRNA gene sequences demonstrated that they belong to the genus Burkholderia, with Burkholderia zhejiangensis as most closely related formally named species; this relationship was confirmed through comparative gyrB sequence analysis. Whole-cell fatty acid analysis supported their assignment to the genus Burkholderia. Burkholderia sp. strain YI23, for which a whole-genome sequence is available, represents the same taxon, as demonstrated by its highly similar 16S rRNA (100% similarity) and gyrB (99.1-99.7%) gene sequences. The results of DNA-DNA hybridization experiments and physiological and biochemical characterization further substantiated the genotypic and phenotypic distinctiveness of the Argentinian soil isolates, for which the name Burkholderia cordobensis sp. nov. is proposed, with strain MMP81(T) ( = LMG 27620(T) = CCUG 64368(T)) as the type strain.

  2. Soil organic carbon as a factor in passive microwave retrievals of soil water content over agricultural croplands

    NASA Astrophysics Data System (ADS)

    Manns, Hida R.; Berg, Aaron A.; Colliander, Andreas

    2015-09-01

    Remote sensing has the potential to deliver global soil water content (SWC) on vast scales with frequent revisit times for progress in the fields of climate, weather forecasting, agriculture and hydrology. Although surface roughness, vegetation and soil texture have been established as sources of variability in passive microwave interpretation, soil organic carbon (SOC) has not typically been considered as a factor that affects SWC estimation during field sampling campaigns. SOC was observed along with soil texture and bulk density during the Soil Moisture Active Passive Validation Experiment in 2012 (SMAPVEX12), the Soil Moisture Active Passive (SMAP) satellite algorithm development field sampling campaign held June 6 to July 19 in Southern Manitoba, Canada. Aerial measurements from the PALS (Passive Active L-band System) instrument were recorded over agricultural fields and forest areas from aircraft while SWC was measured simultaneously on the ground with resistance probes on 17 sampling dates. Additionally, fields were sampled for surface roughness, vegetation growth and water content, soil and vegetation temperature and soil physical characteristics. A soil core was collected on each field each sampling time to assess bulk density, soil particle size and SOC. SOC accounted for more variability in the anomalies between PALS and ground sampled SWC than sand, clay or bulk density, although all soil variables explained significant variability. With analysis by partial least squares multiple regression over 11 sampling dates and 39 fields where both ground and PALS data were well represented, only SOC contributed significantly to the regression of SWC beyond the variance all soil variables had in common. The significance of SOC in the relative SWC anomalies was highest in very wet and very dry conditions and in loam soil over all sampling dates, while bulk density was more significant in sand soils. This analysis suggests SOC is a simple variable that incorporates

  3. Quantification of parameters controlling the carbon stocks in German agricultural soils

    NASA Astrophysics Data System (ADS)

    Vos, Cora; Don, Axel; Freibauer, Annette; Heidkamp, Arne; Prietz, Roland

    2016-04-01

    Within the framework of UNFCCC, Germany is obligated to report on its greenhouse gas emissions from soils. This also includes the emissions in the agricultural sector. Changes in soil carbon stocks are a major source of CO2 that need to be reported. Until now there are only regional inventories of the soil carbon stocks in the agricultural sector while for the forestry sector a repeated national inventory exists. In order to report on changes in soil carbon stocks in agricultural soils, a consistent, representative and quantitative dataset of agricultural soil properties, especially on carbon stocks and management data is necessary. In the course of the German Agricultural Soil Inventory 3109 agricultural sites are examined. Up to January 2016, 2450 sites were sampled. The sites are sampled in five depth increments and all samples are analyzed in the same laboratory. Of the sampled sites the laboratory analyses are completed for 1312 sites. The samples of all depth increments were analyzed for their texture, bulk density, pH, electric conductivity, stone and root content, organic and inorganic carbon content and nitrogen content. The data are coupled with management data covering the past ten years and with climate data. They are analyzed with multivariate statistical techniques (e.g. mixed effects models, additive models, random forest) to quantify the parameters that control the carbon stocks in German agricultural soils. First descriptive results show that the mean soil carbon stocks down to a depth of 100 cm are 126.1 t ha-1 (range 8.9-1158.9 t ha-1). The mean stocks only for croplands are 102.6 t ha-1 (range 8.9-1158.9 t ha-1), while for grasslands the mean stock is 184.1 t ha-1 (range 19.4-937.8 t ha-1). In total the soil scientists found a surprisingly high proportion of disturbed and unusual soil profiles, indicating intensive human modifications of agricultural soils through e.g. deep ploughing. The data set of the German Agricultural Soil Inventory is the

  4. Quantification of parameters controlling the carbon stocks in German agricultural soils

    NASA Astrophysics Data System (ADS)

    Vos, Cora; Don, Axel; Freibauer, Annette; Heidkamp, Arne; Prietz, Roland

    2016-04-01

    Within the framework of UNFCCC, Germany is obligated to report on its greenhouse gas emissions from soils. This also includes the emissions in the agricultural sector. Changes in soil carbon stocks are a major source of CO2 that need to be reported. Until now there are only regional inventories of the soil carbon stocks in the agricultural sector while for the forestry sector a repeated national inventory exists. In order to report on changes in soil carbon stocks in agricultural soils, a consistent, representative and quantitative dataset of agricultural soil properties, especially on carbon stocks and management data is necessary. In the course of the German Agricultural Soil Inventory 3109 agricultural sites are examined. Up to January 2016, 2450 sites were sampled. The sites are sampled in five depth increments and all samples are analyzed in the same laboratory. Of the sampled sites the laboratory analyses are completed for 1312 sites. The samples of all depth increments were analyzed for their texture, bulk density, pH, electric conductivity, stone and root content, organic and inorganic carbon content and nitrogen content. The data are coupled with management data covering the past ten years and with climate data. They are analyzed with multivariate statistical techniques (e.g. mixed effects models, additive models, random forest) to quantify the parameters that control the carbon stocks in German agricultural soils. First descriptive results show that the mean soil carbon stocks down to a depth of 100 cm are 126.1 t ha‑1 (range 8.9-1158.9 t ha‑1). The mean stocks only for croplands are 102.6 t ha‑1 (range 8.9-1158.9 t ha‑1), while for grasslands the mean stock is 184.1 t ha‑1 (range 19.4-937.8 t ha‑1). In total the soil scientists found a surprisingly high proportion of disturbed and unusual soil profiles, indicating intensive human modifications of agricultural soils through e.g. deep ploughing. The data set of the German Agricultural Soil

  5. Plant-Parasitic Nematodes in Maine Agricultural Soils

    PubMed Central

    Huettel, W N.; Francl, L. J.; Henn, A.; Bourgoin, T.

    1990-01-01

    In a survey of plant-parasitic nematodes associated with agricultural crops in nine Maine counties, 744 soil samples from 26 potential host plants were analyzed between November 1987 and January 1989. The most commonly encountered nematode genus was Pratylenchus, occurring in 85% of the samples from most crops, except blueberries and onions. Pratylenchus penetrans and P. crenatus were found commonly as species mixtures, with P. penetrans composing 40-80% of the mixture. Meloidogyne hapla was encountered in 16% of the samples in four counties, generally in potato rotations. Other nematodes encountered were Aphelenchoides spp., Criconemella curvature, Ditylenchus spp., Helicotylenchus pseudorobustus, H. digonicus, Heterodera trifolii, Paratylenchus projectus, Trichodorus spp., Tylenchorhynchus maximus, and Xiphinema americanum. Potato fields were the most heavily sampled and thus weighted the statewide results. PMID:19287791

  6. Soil Sampling Techniques For Alabama Grain Fields

    NASA Technical Reports Server (NTRS)

    Thompson, A. N.; Shaw, J. N.; Mask, P. L.; Touchton, J. T.; Rickman, D.

    2003-01-01

    Characterizing the spatial variability of nutrients facilitates precision soil sampling. Questions exist regarding the best technique for directed soil sampling based on a priori knowledge of soil and crop patterns. The objective of this study was to evaluate zone delineation techniques for Alabama grain fields to determine which method best minimized the soil test variability. Site one (25.8 ha) and site three (20.0 ha) were located in the Tennessee Valley region, and site two (24.2 ha) was located in the Coastal Plain region of Alabama. Tennessee Valley soils ranged from well drained Rhodic and Typic Paleudults to somewhat poorly drained Aquic Paleudults and Fluventic Dystrudepts. Coastal Plain s o i l s ranged from coarse-loamy Rhodic Kandiudults to loamy Arenic Kandiudults. Soils were sampled by grid soil sampling methods (grid sizes of 0.40 ha and 1 ha) consisting of: 1) twenty composited cores collected randomly throughout each grid (grid-cell sampling) and, 2) six composited cores collected randomly from a -3x3 m area at the center of each grid (grid-point sampling). Zones were established from 1) an Order 1 Soil Survey, 2) corn (Zea mays L.) yield maps, and 3) airborne remote sensing images. All soil properties were moderately to strongly spatially dependent as per semivariogram analyses. Differences in grid-point and grid-cell soil test values suggested grid-point sampling does not accurately represent grid values. Zones created by soil survey, yield data, and remote sensing images displayed lower coefficient of variations (8CV) for soil test values than overall field values, suggesting these techniques group soil test variability. However, few differences were observed between the three zone delineation techniques. Results suggest directed sampling using zone delineation techniques outlined in this paper would result in more efficient soil sampling for these Alabama grain fields.

  7. Effects of agricultural practices of three crops on the soil communities under Mediterranean conditions: field evaluation.

    NASA Astrophysics Data System (ADS)

    Leitão, Sara; José Cerejeira, Maria; Abreu, Manuela; Sousa, José Paulo

    2014-05-01

    Sustainable agricultural production relies on soil communities as the main actors in key soil processes necessary to maintain sustainable soil functioning. Soil biodiversity influences soil physical and chemical characteristics and thus the sustainability of crop and agro-ecosystems functioning. Agricultural practices (e.g.: soil tillage, pesticides and fertilizer applications, irrigation) may affects negatively or positively soil biodiversity and abundances by modifying the relationships between organisms in the soil ecosystem. The present study aimed to study the influence of agricultural practices of three crops (potato, onion and maize) under Mediterranean climate conditions on soil macro- and mesofauna during their entire crop cycles. Effects on soil communities were assessed at a higher tier of environmental risk assessment comprising field testing of indigenous edaphic communities in a selected study-site located in a major agriculture region of Central Portugal, Ribatejo e Oeste, neighbouring protected wetlands. A reference site near the agricultural field site was selected as a Control site to compare the terrestrial communities' composition and variation along the crop cycle. The field soil and Control site soil are sandy loam soils. Crops irrigation was performed by center-pivot (automated sprinkler that rotates in a half a circle area) and by sprinklers. Soil macro- and mesofauna were collected at both sites (field and Control) using two methodologies through pitfall trapping and soil sampling. The community of soil macro- and mesofauna of the three crops field varied versus control site along the crops cycles. Main differences were due to arachnids, coleopterans, ants and adult Diptera presence and abundance. The feeding activity of soil fauna between control site and crop areas varied only for potato and onion crops vs. control site but not among crops. Concentration of pesticides residues in soil did not cause apparent negative effects on the soil

  8. Trace metal enrichment in agricultural soils of Jianghan Plain

    NASA Astrophysics Data System (ADS)

    Zhao, R.; Ying, S.; Daniel, J. N.; Bu, J.; Gan, Y.; Wang, Y.; Schaefer, M.; Fendorf, S. E.

    2014-12-01

    Coal consumption in China is increasing annually due to constantly rising energy demand. As a result, a massive amount of coal combustion byproducts, particularly in the form of fly ash, are expelled from power plants and distributed through atmospheric transport. The fly ash is eventually deposited on to land, potentially contaminating agricultural soils. Coal fly ash contains high concentration of a suite of toxic trace metals including lead, chromium, and arsenic. In this study, we surveyed the concentration of trace metals in agricultural soils at 131 sites within a 20 km radius of Yangluo Power Plant, a 2400 MW plant within the highly populated Jianghan Plain of Central China. Using X-ray fluorecence (XRF) spectrometry, the total concentration of trace metals in homogenized surface and subsurface soil samples were measured to calculate the corresponding enrichment factor at each site. Our initial findings demonstrate that Pb is enriched in a majority of sites, independent of land use, whereas As and Cr are generally not enriched in this region. Further studies using Pb isotopes as a source-tracing tool will help determine the Pb pollution's origin. Ultimately, the results of this study may inform whether crops grown within the Jianghan Plain have the potential of being contaminated by metals emitted from coal power plants.

  9. Does North Appalachian Agriculture Contribute to Soil Carbon Sequestration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agricultural systems are important for world ecosystems. They can be managed to moderate CO2 emissions. World soils can be both a sink and source of atmospheric CO2, but it is a slow process. Data from long-term soil management experiments are needed to assess soil carbon (C) sink capacity through a...

  10. Can biosolids reduce wind erosion of agricultural soils?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The application of biosolids to agricultural land has the potential to improve soil health and crop production. In addition, organic material contained in biosolids may enhance biological activity, retention of soil water, and soil aggregation. Thus, there is a likelihood that biosolids applied to s...

  11. Nitrogen loss from windblown agricultural soils in the Columbia Plateau

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wind erosion of agricultural soils can degrade both air quality and soil productivity in the Columbia Plateau of the Pacific Northwest United States. Soils in the region contain fine particles that, when suspended, are highly susceptible to long range transport in the atmosphere. Nitrogen (N) associ...

  12. CO2 emissions from organic soils under agricultural use

    NASA Astrophysics Data System (ADS)

    Bader, Cédric; Leifeld, Jens; Müller, Moritz; Schulin, Rainer

    2015-04-01

    The organic soils of peatlands represent a major global sink for terrestrial carbon. Agricultural use of organic soils requires drainage, changing conditions in these soils from anoxic to oxic. As a consequence, the organic carbon that had been accumulated often over millennia is rapidly mineralized, so that these soils then are no longer a sink but become a source of CO2. The aim of our study is to analyse the amount and origin of CO2 emitted from organic soils under three land-use types (forest, arable cropland and grassland). Our study area is located in the Bernese Lakeland (CH). The peatlands of this region were drained in the 1870ies, and the site as well as the surrounding area are now managed by a state prison. Since decades our study site is under the same land-use. In Oktober 2013 we took 4 replicate soil cores of all land-uses with respect to a certain distance from a major drainage ditch. Each core was analysed for its bulk density and carbon content. 9 soil samples from a depth of 20-30 cm were analysed for their F14C and δ13C values and later divided into 18 subsamples. Half of them were mixed with 0.2-0.4 g of labelled corn stalk enriched in δ13C (δ13C=2000) in order to mimic plant residue inputs in the field. The moisture content of these samples was equilibrated at a pF-value of 2 before incubating the samples in a Respicond VII analyser for several weeks at 20° C. By trapping the respired CO2 in NaOH and precipitating it as BaCO3 we were able to analyse its F14C and δ13C value. This enabled us to determine to what extent the CO2 originated from old peat, young plant residues or the added maize stalk. Generally the cropland samples showed the highest respiration rates, lowest F14C values and highest carbon stocks. The organic soils under the forest were degraded the most and showed low respiration rates. Analyzing the F14C values of the CO2 revealed that peat contributes most to the respiration and its degradation is fastest in the cropland

  13. [Quantitative Analysis of Mn in Soil Samples Using LIBS].

    PubMed

    Zhang, Bao-hua; Jiang, Yong-cheng; Zhang, Xian-yan; Cui, Zhi-feng

    2015-06-01

    The trace element of Manganese element in the agricultural farm (Anhui Huaiyuan Nongkang) soil was quantitatively analyzed by Laser-induced breakdown spectroscopy. The line of 403.1 nm was selected as the analysis line of Mn. The matrix element of Fe in soil was chosen as the internal calibration element and the analysis line was 407.2 nm. Ten soil samples were used to construct calibration curves with traditional method and internal standard method, and four soil samples were selected as test samples. The experimental results showed that the fitting correlation coefficient (r) is 0.954 when using the traditional method, the maximum relative error of the measurement samples is 5.72%, and the detection limit of Mn in soil is 93 mg x kg(-1). While using the internal standard method to construct the calibration curve, the fitting correlation coefficient (r) is 0.983, the relative error of measurement samples is reduced to 4.1%, and the detection limit of Mn in soil is 71 mg x kg(-1). The result indicates that LIBS technique can be used to detect trace element Mn in soil. In a certain extent, the internal standard method can improve the accuracy of measurement.

  14. Soil type as factor controlling the effects of forest transformation to agricultural use in soil aggregation and related properties

    NASA Astrophysics Data System (ADS)

    Chrenková, Katarína; Mataix-Solera, Jorge; Dlapa, Pavel; Arcenegui, Victoria

    2014-05-01

    The stability of aggregates has an important role in soil functioning and its behavior to avoid erosion and degradation, the ability to transfer liquids and gases, which are important features for crop production and ecosystem health (Tisdall and Oades, 1982). It's also a property that is highly influenced by land use and management (Angers et al., 1993). The stability of aggregates provides key information about the capacity of soil functions that defines the soil quality. This study has aimed to identify the long-term effects of forest transformation on agricultural use on soil structure and related properties. For the research was chosen seven localities in the Alicante Province (E Spain) with different soil types in all cases to compare how the land use changes can affect as a function of soil type and characteristics. In every site, samples were collected from agricultural land use (dry crops with tillage management), and in forest areas close to them with similar soil type that are used as references. On the samples, selected physical and chemical properties were analyzed such as Soil aggregate stability (AS), Organic matter (OM), Mean weight diameter (MWD) of aggregates and Water repellency (WR). As expected, in all cases the AS was significant lower in agricultural sites than in forest. But in some cases the differences were much higher than in others. In forest sites the AS varied between 46 to 82% while in agricultural sites ranged between 14 to 45%. The results showed strong positive correlation of AS with OM. The lowest initial values of AS were found in wettable sandy soils. The agricultural land use lead to relative decrease in AS by 39 to 79% compared to forest soils, indicating that some soils are much more vulnerable to land use than others. These differences can be explained mainly because intrinsic soil properties, such as OM content, texture, and WR. Particularly, the decrease in OM content and absence of WR are responsible for the decrease in

  15. Agriculture Canada Central Saskatchewan Vector Soils Data

    NASA Technical Reports Server (NTRS)

    Knapp, David; Hall, Forrest G. (Editor); Rostad, Harold

    2000-01-01

    This data set consists of GIS layers that describe the soils of the BOREAS SSA. These original data layers were submitted as vector data in ARC/INFO EXPORT format. These data also include the soil name and soil layer files, which provide additional information about the soils. There are three sets of attributes that include information on the primary, secondary, and tertiary soil type within each polygon. Thus, there is a total of nine main attributes in this data set.

  16. Soil organic carbon fractionation for improving agricultural soil quality diagnosis in different management practices.

    NASA Astrophysics Data System (ADS)

    Trigalet, Sylvain; Chartin, Caroline; Kruger, Inken; Carnol, Monique; Van Oost, Kristof; van Wesemael, Bas

    2016-04-01

    Preserving ecosystem functions of soil organic matter (SOM) in soils is a key challenge. The need for an efficient diagnosis of SOM state in agricultural soils is a priority in order to facilitate the detection of changes in soil quality as a result of changes in management practices. The nature of SOM is complex and cannot readily be monitored due to the heterogeneity of its components. Assessment of the SOM level dynamics, typically characterized as the bulk soil organic carbon (SOC), can be refined by taking into account carbon pools with different turnover rates and stability. Fractionating bulk SOC in meaningful soil organic fractions helps to better diagnose SOC status. By separating carbon associated with clay and fine silt particles (stable carbon with slow turnover rate) and carbon non-associated with this fraction (labile and intermediate carbon with higher turnover rates), effects of management can be detected more efficiently at different spatial and temporal scales. Until now, most work on SOC fractionation has focused on small spatial scales along management or time gradients. The present case study focuses on SOC fractionation applied in order to refine the interpretation of organic matter turnover and SOC sequestration for regional units in Wallonia with comparable climate, management and, to a certain extent, soil conditions. In each unit, random samples from specific land uses are analyzed in order to assess the Normal Operative Ranges (NOR) of SOC fraction contents for each unit and land use combination. Thus, SOC levels of the different fractions of a specific field in a given unit can be compared to its corresponding NOR. It will help to better diagnose agricultural soil quality in terms of organic carbon compared to a bulk SOC diagnosis.

  17. Estimations of soil fertility in physically degraded agricultural soils through selective accounting of fine earth and gravel fractions

    NASA Astrophysics Data System (ADS)

    Nagaraja, Mavinakoppa S.; Bhardwaj, Ajay Kumar; Prabhakara Reddy, G. V.; Srinivasamurthy, Chilakunda A.; Kumar, Sandeep

    2016-06-01

    Soil fertility and organic carbon (C) stock estimations are crucial to soil management, especially that of degraded soils, for productive agricultural use and in soil C sequestration studies. Currently, estimations based on generalized soil mass (hectare furrow basis) or bulk density are used which may be suitable for normal agricultural soils, but not for degraded soils. In this study, soil organic C, available nitrogen (N), available phosphorus (P2O5) and available potassium (K2O), and their stocks were estimated using three methods: (i) generalized soil mass (GSM, 2 million kg ha-1 furrow soil), (ii) bulk-density-based soil mass (BDSM) and (iii) the proportion of fine earth volume (FEV) method, for soils sampled from physically degraded lands in the eastern dry zone of Karnataka State in India. Comparative analyses using these methods revealed that the soil organic C, N, P2O and K2O stocks determined by using BDSM were higher than those determined by the GSM method. The soil organic C values were the lowest in the FEV method. The GSM method overestimated soil organic C, N, P2O and K2O by 9.3-72.1, 9.5-72.3, 7.1-66.6 and 9.2-72.3 %, respectively, compared to FEV-based estimations for physically degraded soils. The differences among the three methods of estimation were lower in soils with low gravel content and increased with an increase in gravel volume. There was overestimation of soil organic C and soil fertility with GSM and BDSM methods. A reassessment of methods of estimation was, therefore, attempted to provide fair estimates for land development projects in degraded lands.

  18. Impact of an intensive management on soil biochemical and biological properties in an agricultural soil of Southern Italy

    NASA Astrophysics Data System (ADS)

    Scotti, R.; D'Ascoli, R.; Rao, M. A.; Marzaioli, R.; Rutigliano, F. A.; Gianfreda, L.

    2009-04-01

    An intensive management of agricultural soils is widely carried out to increase vegetation productivity. Nevertheless, the large use of machineries, chemical fertilizers and pesticides can often cause, in time, a substantial decline in soil fertility by affecting soil physical and chemical properties and, in turn, growth and activity of soil microbial community. In fact, alteration in soil structure, nutrient losses and, in particular, changes in quality and quantity of soil organic matter are some of the principal soil degradation processes deriving from an intensive agricultural management that can affect, in different ways, soil biochemical and biological properties. The aim of this research was to assess the impact of intensive management on agricultural soils by measuring soil physical, chemical and biochemical/biological properties. The use of appropriate indicators as quantitative tools could allow to assess soil quality. Moreover, although soil physical and chemical properties have received great attention, soil biochemical/biological properties, such as enzyme activities and microbial biomass, functionally related properties involved in the nutrient cycles, can be considered as sensitive indicators of soil quality and health changes because, they show a faster turn over compared to soil organic matter. Our attention was focused on the Plane of Sele river (Campania region, Italy), an area characterized by an intensive agriculture and greenhouse cultures. Twenty-five farms were chosen, with the aid of regional soil map, in order to get soils with different physical and chemical properties. As common trait, the selected farms, all with greenhouse cultures, used no organic amendments but only mineral compounds to fertilize soils. Moreover, to better understand the impact of intensive agricultural practices on soil of each farm, control soils from orchards or uncultivated plots were chosen. In each farm soil samples were collected in three different plots

  19. Performance evaluation soil samples utilizing encapsulation technology

    DOEpatents

    Dahlgran, James R.

    1999-01-01

    Performance evaluation soil samples and method of their preparation using encapsulation technology to encapsulate analytes which are introduced into a soil matrix for analysis and evaluation by analytical laboratories. Target analytes are mixed in an appropriate solvent at predetermined concentrations. The mixture is emulsified in a solution of polymeric film forming material. The emulsified solution is polymerized to form microcapsules. The microcapsules are recovered, quantitated and introduced into a soil matrix in a predetermined ratio to form soil samples with the desired analyte concentration.

  20. Performance evaluation soil samples utilizing encapsulation technology

    DOEpatents

    Dahlgran, J.R.

    1999-08-17

    Performance evaluation soil samples and method of their preparation uses encapsulation technology to encapsulate analytes which are introduced into a soil matrix for analysis and evaluation by analytical laboratories. Target analytes are mixed in an appropriate solvent at predetermined concentrations. The mixture is emulsified in a solution of polymeric film forming material. The emulsified solution is polymerized to form microcapsules. The microcapsules are recovered, quantitated and introduced into a soil matrix in a predetermined ratio to form soil samples with the desired analyte concentration. 1 fig.

  1. Occurrence of veterinary antibiotics and progesterone in broiler manure and agricultural soil in Malaysia.

    PubMed

    Ho, Yu Bin; Zakaria, Mohamad Pauzi; Latif, Puziah Abdul; Saari, Nazamid

    2014-08-01

    Repeated applications of animal manure as fertilizer are normal agricultural practices that may release veterinary antibiotics and hormones into the environment from treated animals. Broiler manure samples and their respective manure-amended agricultural soil samples were collected in selected locations in the states of Selangor, Negeri Sembilan and Melaka in Malaysia to identify and quantify veterinary antibiotic and hormone residues in the environment. The samples were analyzed using ultrasonic extraction followed by solid phase extraction (SPE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The broiler manure samples were found to be contaminated with at least six target analytes, namely, doxycycline, enrofloxacin, flumequine, norfloxacin, trimethoprim and tylosin. These analytes were detected in broiler manure samples with maximum concentrations reaching up to 78,516 μg kg(-1) dry weight (DW) (doxycycline). For manure-amended agricultural soil samples, doxycycline and enrofloxacin residues were detected in every soil sample. The maximum concentration of antibiotic detected in soil was 1331 μg kg(-1) DW (flumequine). The occurrence of antibiotics and hormones in animal manure at high concentration poses a risk of contaminating agricultural soil via fertilization with animal manure. Some physico-chemical parameters such as pH, total organic carbon (TOC) and metal content played a considerable role in the fate of the target veterinary antibiotics and progesterone in the environment. It was suggested that these parameters can affect the adsorption of pharmaceuticals to solid environmental matrices. PMID:24836135

  2. Occurrence of veterinary antibiotics and progesterone in broiler manure and agricultural soil in Malaysia.

    PubMed

    Ho, Yu Bin; Zakaria, Mohamad Pauzi; Latif, Puziah Abdul; Saari, Nazamid

    2014-08-01

    Repeated applications of animal manure as fertilizer are normal agricultural practices that may release veterinary antibiotics and hormones into the environment from treated animals. Broiler manure samples and their respective manure-amended agricultural soil samples were collected in selected locations in the states of Selangor, Negeri Sembilan and Melaka in Malaysia to identify and quantify veterinary antibiotic and hormone residues in the environment. The samples were analyzed using ultrasonic extraction followed by solid phase extraction (SPE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The broiler manure samples were found to be contaminated with at least six target analytes, namely, doxycycline, enrofloxacin, flumequine, norfloxacin, trimethoprim and tylosin. These analytes were detected in broiler manure samples with maximum concentrations reaching up to 78,516 μg kg(-1) dry weight (DW) (doxycycline). For manure-amended agricultural soil samples, doxycycline and enrofloxacin residues were detected in every soil sample. The maximum concentration of antibiotic detected in soil was 1331 μg kg(-1) DW (flumequine). The occurrence of antibiotics and hormones in animal manure at high concentration poses a risk of contaminating agricultural soil via fertilization with animal manure. Some physico-chemical parameters such as pH, total organic carbon (TOC) and metal content played a considerable role in the fate of the target veterinary antibiotics and progesterone in the environment. It was suggested that these parameters can affect the adsorption of pharmaceuticals to solid environmental matrices.

  3. Bacterial indicator of agricultural management for soil under no-till crop production.

    PubMed

    Figuerola, Eva L M; Guerrero, Leandro D; Rosa, Silvina M; Simonetti, Leandro; Duval, Matías E; Galantini, Juan A; Bedano, José C; Wall, Luis G; Erijman, Leonardo

    2012-01-01

    The rise in the world demand for food poses a challenge to our ability to sustain soil fertility and sustainability. The increasing use of no-till agriculture, adopted in many areas of the world as an alternative to conventional farming, may contribute to reduce the erosion of soils and the increase in the soil carbon pool. However, the advantages of no-till agriculture are jeopardized when its use is linked to the expansion of crop monoculture. The aim of this study was to survey bacterial communities to find indicators of soil quality related to contrasting agriculture management in soils under no-till farming. Four sites in production agriculture, with different soil properties, situated across a west-east transect in the most productive region in the Argentinean pampas, were taken as the basis for replication. Working definitions of Good no-till Agricultural Practices (GAP) and Poor no-till Agricultural Practices (PAP) were adopted for two distinct scenarios in terms of crop rotation, fertilization, agrochemicals use and pest control. Non-cultivated soils nearby the agricultural sites were taken as additional control treatments. Tag-encoded pyrosequencing was used to deeply sample the 16S rRNA gene from bacteria residing in soils corresponding to the three treatments at the four locations. Although bacterial communities as a whole appeared to be structured chiefly by a marked biogeographic provincialism, the distribution of a few taxa was shaped as well by environmental conditions related to agricultural management practices. A statistically supported approach was used to define candidates for management-indicator organisms, subsequently validated using quantitative PCR. We suggest that the ratio between the normalized abundance of a selected group of bacteria within the GP1 group of the phylum Acidobacteria and the genus Rubellimicrobium of the Alphaproteobacteria may serve as a potential management-indicator to discriminate between sustainable vs. non

  4. Implications of Using Thermal Desorption to Remediate Contaminated Agricultural Soil: Physical Characteristics and Hydraulic Processes.

    PubMed

    O'Brien, Peter L; DeSutter, Thomas M; Casey, Francis X M; Derby, Nathan E; Wick, Abbey F

    2016-07-01

    Given the recent increase in crude oil production in regions with predominantly agricultural economies, the determination of methods that remediate oil contamination and allow for the land to return to crop production is increasingly relevant. Ex situ thermal desorption (TD) is a technique used to remediate crude oil pollution that allows for reuse of treated soil, but the properties of that treated soil are unknown. The objectives of this research were to characterize TD-treated soil and to describe implications in using TD to remediate agricultural soil. Native, noncontaminated topsoil and subsoil adjacent to an active remediation site were separately subjected to TD treatment at 350°C. Soil physical characteristics and hydraulic processes associated with agricultural productivity were assessed in the TD-treated samples and compared with untreated samples. Soil organic carbon decreased more than 25% in both the TD-treated topsoil and the subsoil, and total aggregation decreased by 20% in the topsoil but was unaffected in the subsoil. The alteration in these physical characteristics explains a 400% increase in saturated hydraulic conductivity in treated samples as well as a decrease in water retention at both field capacity and permanent wilting point. The changes in soil properties identified in this study suggest that TD-treated soils may still be suitable for sustaining vegetation, although likely at a slightly diminished capacity when directly compared with untreated soils. PMID:27380094

  5. Implications of Using Thermal Desorption to Remediate Contaminated Agricultural Soil: Physical Characteristics and Hydraulic Processes.

    PubMed

    O'Brien, Peter L; DeSutter, Thomas M; Casey, Francis X M; Derby, Nathan E; Wick, Abbey F

    2016-07-01

    Given the recent increase in crude oil production in regions with predominantly agricultural economies, the determination of methods that remediate oil contamination and allow for the land to return to crop production is increasingly relevant. Ex situ thermal desorption (TD) is a technique used to remediate crude oil pollution that allows for reuse of treated soil, but the properties of that treated soil are unknown. The objectives of this research were to characterize TD-treated soil and to describe implications in using TD to remediate agricultural soil. Native, noncontaminated topsoil and subsoil adjacent to an active remediation site were separately subjected to TD treatment at 350°C. Soil physical characteristics and hydraulic processes associated with agricultural productivity were assessed in the TD-treated samples and compared with untreated samples. Soil organic carbon decreased more than 25% in both the TD-treated topsoil and the subsoil, and total aggregation decreased by 20% in the topsoil but was unaffected in the subsoil. The alteration in these physical characteristics explains a 400% increase in saturated hydraulic conductivity in treated samples as well as a decrease in water retention at both field capacity and permanent wilting point. The changes in soil properties identified in this study suggest that TD-treated soils may still be suitable for sustaining vegetation, although likely at a slightly diminished capacity when directly compared with untreated soils.

  6. Sampling Soil for Characterization and Site Description

    NASA Technical Reports Server (NTRS)

    Levine, Elissa

    1999-01-01

    The sampling scheme for soil characterization within the GLOBE program is uniquely different from the sampling methods of the other protocols. The strategy is based on an understanding of the 5 soil forming factors (parent material, climate, biota, topography, and time) at each study site, and how each of these interact to produce a soil profile with unique characteristics and unique input and control into the atmospheric, biological, and hydrological systems. Soil profile characteristics, as opposed to soil moisture and temperature, vegetative growth, and atmospheric and hydrologic conditions, change very slowly, depending on the parameter being measured, ranging from seasonally to many thousands of years. Thus, soil information, including profile description and lab analysis, is collected only one time for each profile at a site. These data serve two purposes: 1) to supplement existing spatial information about soil profile characteristics across the landscape at local, regional, and global scales, and 2) to provide specific information within a given area about the basic substrate to which elements within the other protocols are linked. Because of the intimate link between soil properties and these other environmental elements, the static soil properties at a given site are needed to accurately interpret and understand the continually changing dynamics of soil moisture and temperature, vegetation growth and phenology, atmospheric conditions, and chemistry and turbidity in surface waters. Both the spatial and specific soil information can be used for modeling purposes to assess and make predictions about global change.

  7. Potential for Recharge in Agricultural Soils of the Mississippi Delta

    NASA Astrophysics Data System (ADS)

    Perkins, K. S.; Nimmo, J. R.; Coupe, R. H.; Rose, C. E.; Manning, M. A.

    2007-12-01

    Ground water models predict that 5 percent or less of precipitation in the Mississippi Delta region recharges the heavily-used alluvial aquifer; however the presence of agricultural chemicals in ground water suggests more substantial recharge. In a preliminary assessment of the potential for aerial recharge through the agricultural soils of the Bogue Phalia basin in the Mississippi Delta, we applied a method for rapidly measuring field- saturated hydraulic conductivity (Kfs) in 26 locations in cotton and soybean fields. The technique makes use of a portable falling-head, small-diameter, single-ring infiltrometer and an analytical formula for Kfs that compensates both for falling head and for subsurface radial spreading. Soil samples were also collected at the surface and at about 6 cm depth at each location for particle size analysis. Kfs values are generally higher than anticipated and vary over more than three orders of magnitude from 1x10-2 to 5x10-6 cm/s. There is also a correlation between Kfs and mean particle size which may prove useful in generalizing recharge rates over larger areas. A 2-m ring infiltration test is planned that will include the use of tracers and subsurface instruments for measuring water content and matric potential from the near surface to about 5 m to evaluate flow and transport below the root zone.

  8. Combination of comprehensive geophysical measurements and conventional soil sampling for high resolution soil mapping

    NASA Astrophysics Data System (ADS)

    Werban, U.; Nuesch, A.; Vienken, T.; Dietrich, P.; Behrens, T.

    2010-12-01

    The focus of the FP7-EU project iSOIL “Interactions between soil related sciences - Linking geophysics, soil science and digital soil mapping” is to develop new and to improve existing strategies and innovative methods for generating accurate, high-resolution soil property maps. Thus we will develop, validate, and evaluate concepts and strategies for transferring measured physical parameter distributions into soil property, soil function and soil threat maps of different scales. The resulting soil property maps can be used for agriculture applications and soil degradation threats studies, e.g. erosion, compaction and soil organic matter decline. A fast and cost efficient way to detect physical parameters of soils at large areas is the application of mobile geophysical platforms. An advantage of these platforms is the flexibility since different kind of instruments can be mounted and combined. Following instruments are used on platforms within iSOIL project: EMI, GPR, gamma-spectrometry and magnetics. Since geophysical methods provide only physical parameters it is essential to combine them with conventional soil sampling methods for ground truthing. Physical parameters have to be converted into soil parameters via (site specific) transfer functions. One focus of the project was the development of measuring designs for the evaluation and combination of different geophysical methods. The application of a hierarchical approach is one way to combine different scales and parameters. The implementation of this approach will be presented and can be summarized as follows: - The first step is a survey of the total area with EMI and gamma-spectrometry. The distance between two lines is 10 - 20 meters. - By means of the geophysical data and a digital elevation model, representative soil sampling points are chosen, via a weighted conditioned latin hypercube sampling scheme (wLHS) based on conditioned latin hypercube sampling (cLHS). - All soil sampling points are probed

  9. Procedures for sampling radium-contaminated soils

    SciTech Connect

    Fleischhauer, H.L.

    1985-10-01

    Two procedures for sampling the surface layer (0 to 15 centimeters) of radium-contaminated soil are recommended for use in remedial action projects. Both procedures adhere to the philosophy that soil samples should have constant geometry and constant volume in order to ensure uniformity. In the first procedure, a ''cookie cutter'' fashioned from pipe or steel plate, is driven to the desired depth by means of a slide hammer, and the sample extracted as a core or plug. The second procedure requires use of a template to outline the sampling area, from which the sample is obtained using a trowel or spoon. Sampling to the desired depth must then be performed incrementally. Selection of one procedure over the other is governed primarily by soil conditions, the cookie cutter being effective in nongravelly soils, and the template procedure appropriate for use in both gravelly and nongravelly soils. In any event, a minimum sample volume of 1000 cubic centimeters is recommended. The step-by-step procedures are accompanied by a description of the minimum requirements for sample documentation. Transport of the soil samples from the field is then addressed in a discussion of the federal regulations for shipping radioactive materials. Interpretation of those regulations, particularly in light of their application to remedial action soil-sampling programs, is provided in the form of guidance and suggested procedures. Due to the complex nature of the regulations, however, there is no guarantee that our interpretations of them are complete or entirely accurate. Preparation of soil samples for radium-226 analysis by means of gamma-ray spectroscopy is described.

  10. Effects of Surfactants on Cryptosporidium parvum Mobility in Agricultural Soils from Illinois and Utah

    NASA Astrophysics Data System (ADS)

    Darnault, C. J.; Koken, E.; Jacobson, A. R.; Powelson, D.

    2011-12-01

    The occurence of the parasitic protozoan Cryptosporidium parvum in rural and agricultural watersheds due to agricultural activities and wildlife is inevitable. Understanding the behavior of C. parvum oocysts in the environment is critical for the protection of public health and the environment. To better understand the mechanisms by which the pathogen moves through soils and contaminates water resources, we study their mobility under conditions representative of real-world scenarios, where both C. parvum and chemicals that affect their fate are present in soils. Surfactants occur widely in soils due to agricultural practices such as wastewater irrigation and the application of pesticides or soil wetting agents. They affect water tension and, consequently, soil infiltration processes and the air-water interfaces in soil pores where C. parvum may be retained. We investigate the effects of surfactants on the mobility of C. parvum oocysts in agricultural soils from Illinois and Utah under unsaturated flow conditions. As it is critical to examine C. parvum in natural settings, we also developed a quantification method using RT-PCR for monitoring C. parvum oocysts in environmental soil and water samples. We optimized physico-chemical parameters to disrupt C. parvum oocysts and extract their DNA, and developed isolation methods to separate C. parvum oocysts from colloids in natural soil samples. The results of this research will lead to the development of an accurate and sensitive molecular method for the monitoring of C. parvum oocysts in environmental soil and water samples, and will further our understanding of the mechanisms controlling the behavior of C. parvum oocysts in soils, in particular the role of vadose zone processes, sorption to soil and surfactants.

  11. Irrigated agriculture and soil salinization in the Maltese islands.

    PubMed

    Vella, Sonya J; Camilleri, Sharlo

    2003-08-01

    In the Maltese islands, soil is one of the most threatened natural resources, being continuously exposed to a multitude of climatic, environmental, and man-induced impacts. The changes in agricultural practices as well as increases in urban development have intensified environmental problems and have accentuated the pressures on agricultural land and fragile semi-natural ecosystems. Between 1956 and 2001, the total agricultural land declined from 20,433 ha to 10,713 ha, however, during the same period, the irrigated land as a percentage of total agricultural land increased from 3.9% to 10.7%. The poor quality of irrigation water sources, and the supply of treated sewage effluent with a high level of salts, contribute to a significant salt input. The extent of salt-affected soils in the Maltese islands is not well-documented, however, field observations and technical reports indicate that soil salinity is a potential constraint for agricultural production. This article gives a comparative review of the salinity status of soils in three case study areas in Malta, the agricultural dryland at Ghammieri, the intensively cultivated irrigated valley of Pwales, and the agricultural land irrigated with treated sewage effluent of the Sant Antnin Sewage Treatment Plant in the South-East of Malta. This analysis is provided in the context of the environmental impact of irrigation on soil quality in the Maltese islands.

  12. Biological indicators of soil quality and soil organic matter characteristics in an agricultural management continuum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Relationships among biological indicators of soil quality and soil organic matter characteristics in a claypan soil were evaluated across a continuum of long-term agricultural practices in Missouri, USA. In addition to chemical and physical soil quality indicators, dehydrogenase and phenol oxidase a...

  13. Analysis of large soil samples for actinides

    DOEpatents

    Maxwell, III; Sherrod L.

    2009-03-24

    A method of analyzing relatively large soil samples for actinides by employing a separation process that includes cerium fluoride precipitation for removing the soil matrix and precipitates plutonium, americium, and curium with cerium and hydrofluoric acid followed by separating these actinides using chromatography cartridges.

  14. Quantification Of Erosion Rates Of Agriculturally Used Soils By Artificial

    NASA Astrophysics Data System (ADS)

    Jha, Abhinand

    2010-05-01

    for 137Cs and 53 days for 7Be), delivery rates, delivery histories, and land use (Fig. 2). An Physical processes, such as water and wind, are the dominant factors moving 137Cs, 7Be tagged soil particles within and between landscape compartments. PIC Figure 2: Generalized sketch illustrating the distributions of 137Cs and 7Be in tilled and undisturbed soils 2 Erosion study at Young Moraine regions of Germany Recently, a study had been performed to evaluate erosion rates in a typical pattern of landscapes in the Young Moraine regions of North-East Germany [5]. The 137Cs concentrations were measured at selected sampling points of various study sites. Among the areas selected for sampling was Basedow, which is a cultivated area, situated north of Berlin. During a master thesis study at university of Bremen in the academic year 2008-2009 [6] a second sampling campaign was performed at the same study site and 137Cs and 7Be concentrations were measured. Two mathematical models (a proportional model and a mass balance model) were applied to estimate erosion or deposition rates giving a distinction between uncultivated or essentially undisturbed soils and cultivated or soils under permanent pasture (Fig.3A). An improved depositional model was developed during this study. The simulation results from this model are presented in Fig.4. Due to the half-life (53.2 days) of 7Be, a mass balance model was developed and used to calculate erosion rates from 7Be (Fig.3B). PIC Figure 3: A: Erosion rates for 137Cs calculated by mass balance model. B: Erosion rates calculated with mass balance model using the 7Be data at Basedow (2008). The results verify that there is long term erosion as a result of wind, water and agricultural practices. The annual erosion rates at Basedow calculated using a mass balance and a proportional model were in the range between 30-50 t ha-1yr-1. These values were comparable to the erosion rates calculated in the previous study [5] by the models mentioned above

  15. Soil Type Identification Using Remotely Sensed Data for Agricultural Purpose

    NASA Astrophysics Data System (ADS)

    Jiji, G. Wiselin; Nadar, Pallavi

    2016-09-01

    Soil assessment plays important role in making decisions for Agriculture. In this paper, an approach by integrating the image processing and pattern recognition techniques to find the type of soil has been presented. The soil from the area of interest is selected and soil indices are extracted as features. Indexing technique is used for faster retrieval. The efficiency of the proposed system is proved using sensitivity, specificity, precision and recall. Our empirical evaluation has a superior retrieval performance over the performance of other works. This work is of great use to the farmers, who need to identify their field's soil type.

  16. Pesticides in soils and ground water in selected irrigated agricultural areas near Havre, Ronan, and Huntley, Montana

    USGS Publications Warehouse

    Clark, D.W.

    1990-01-01

    Three areas in Montana representing a range of agricultural practices and applied pesticides, were studied to document whether agricultural pesticides are being transported into the soil and shallow groundwater in irrigated areas. Analytical scans for triazine herbicides, organic-acid herbicides, and carbamate insecticides were performed on soil and shallow groundwater samples. The results indicate pesticide residue in both types of samples. The concentrations of pesticides in the groundwater were less than Federal health-advisory limits. At the Havre Agricultural Experiment Station, eight wells were installed at two sites. All four soil samples and two of four water samples collected after application of pesticides contained detectable concentrations of atrazine or dicamba. In an area where seed potatoes are grown near Ronan, eight wells were installed at two sites. Pesticides were not detected after initial application of pesticides and irrigation water. The site was resampled after irrigation water was reapplied, and aldicarb metabolities were detected in four of five soil samples and one of five water samples. At the Huntley Agricultural Experiment Station, five wells were installed in a no-tillage corn field where atrazine was applied in 1987. Soil and water samples were collected in June and July 1988; pesticides were not detected in any samples. Results indicate residue of two pesticides in soil samples and three soluble pesticides in groundwater samples. Therefore, irrigated agricultural areas in Montana might be susceptible to transport of soluble pesticides through permeable soil to the shallow groundwater system. (USGS)

  17. Mapping Soil Salinity with ECa-Directed Soil Sampling: History, Protocols, Guidelines, Applications, and Future Research Trends

    NASA Astrophysics Data System (ADS)

    Corwin, Dennis

    2014-05-01

    Soil salinity is a spatially complex and dynamic property of soil that influences crop yields when the threshold salinity level is exceeded. Mapping soil salinity is necessary for soil classification, reclamation, crop selection, and site-specific irrigation management of salt-affected soils in the arid and semi-arid agricultural regions of the world. Because of its spatial and temporal heterogeneity soil salinity is difficult to map and monitor at field scales. There are various methods for characterizing soil salinity variability, but none of these approaches has been as extensively investigated and is as reliable and cost effective as apparent soil electrical conductivity (ECa) directed soil sampling. Geospatial measurements of ECa are well-suited for characterizing soil salinity spatial distribution because they are reliable, quick, and easy to take with GPS-based mobilized ECa measurement equipment. However, ECa is influenced by a variety of soil properties, which makes the measurement of soil salinity at field scale problematic. It is the goal of this presentation to provide an overview of the field-scale characterization of soil salinity distribution using ECa-directed soil sampling. A historical perspective, protocols and guidelines, strengths and limitations, applications, and future trends are presented for characterizing spatial and temporal variation in soil salinity using ECa-directed soil sampling. Land resource managers, farmers, extension specialists, soil classification specialists, and Natural Resource Conservation Service field staff are the beneficiaries of field-scale maps of soil salinity.

  18. 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

  19. Profiling nematode communities in unmanaged flowerbed and agricultural field soils in Japan by DNA barcode sequencing.

    PubMed

    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.

  20. Actinide Recovery Method for Large Soil Samples

    SciTech Connect

    Maxwell, S.L. III; Nichols, S.

    1998-11-01

    A new Actinide Recovery Method has been developed by the Savannah River Site Central Laboratory to preconcentrate actinides in very large soil samples. Diphonix Resin(r) is used eliminate soil matrix interferences and preconcentrate actinides after soil leaching or soil fusion. A rapid microwave digestion technique is used to remove the actinides from the Diphonix Resin(r). After the resin digestion, the actinides are recovered in a small volume of nitric acid which can be easily loaded onto small extraction-chromatography columns, such as TEVA Resin(r), U-TEVA Resin(r) or TRU Resin(r) (Eichrom Industries). This method enables the application of small, selective extraction-columns to recover actinides from very large soil samples with high selectivity, consistent tracer recoveries and minimal liquid waste.

  1. Soil biota and agriculture production in conventional and organic farming

    NASA Astrophysics Data System (ADS)

    Schrama, Maarten; de Haan, Joj; Carvalho, Sabrina; Kroonen, Mark; Verstegen, Harry; Van der Putten, Wim

    2015-04-01

    Sustainable food production for a growing world population requires a healthy soil that can buffer environmental extremes and minimize its losses. There are currently two views on how to achieve this: by intensifying conventional agriculture or by developing organically based agriculture. It has been established that yields of conventional agriculture can be 20% higher than of organic agriculture. However, high yields of intensified conventional agriculture trade off with loss of soil biodiversity, leaching of nutrients, and other unwanted ecosystem dis-services. One of the key explanations for the loss of nutrients and GHG from intensive agriculture is that it results in high dynamics of nutrient losses, and policy has aimed at reducing temporal variation. However, little is known about how different agricultural practices affect spatial variation, and it is unknown how soil fauna acts this. In this study we compare the spatial and temporal variation of physical, chemical and biological parameters in a long term (13-year) field experiment with two conventional farming systems (low and medium organic matter input) and one organic farming system (high organic matter input) and we evaluate the impact on ecosystem services that these farming systems provide. Soil chemical (N availability, N mineralization, pH) and soil biological parameters (nematode abundance, bacterial and fungal biomass) show considerably higher spatial variation under conventional farming than under organic farming. Higher variation in soil chemical and biological parameters coincides with the presence of 'leaky' spots (high nitrate leaching) in conventional farming systems, which shift unpredictably over the course of one season. Although variation in soil physical factors (soil organic matter, soil aggregation, soil moisture) was similar between treatments, but averages were higher under organic farming, indicating more buffered conditions for nutrient cycling. All these changes coincide with

  2. Fate of phthalates and BPA in agricultural and non-agricultural soils of the Paris area (France).

    PubMed

    Tran, Bich Chau; Teil, Marie-Jeanne; Blanchard, Martine; Alliot, Fabrice; Chevreuil, Marc

    2015-07-01

    This study (i) investigated the concentration levels of nine phthalates and bisphenol A (BPA) in sludge samples originating from a French wastewater treatment plant (WWTP), (ii) studied the distribution of target compounds according to soil depth and calculated their half-lives, and (iii) compared the contamination level of the agricultural soil with those of soils with other land uses. The sludge contamination levels varied from a few hundred nanograms per gram dry weight (dw) for diethyl phthalate (DEP), di-iso-butyl phthalate (DiBP), di-n-butyl phthalate (DnBP), and butyl-benzyl phthalate (BBP) to a few micrograms per gram dw for diethylhexyl phthalate (DEHP), di-iso-nonyl phthalate (DiNP), and di-iso-decyl phthalate (DiDP). After sludge application, an 8-fold increase for DEHP level and a 3-fold increase for BPA level occurred in the surface horizon of the soil. The mean distribution of phthalates according to the depth showed a positive gradient for the low molecular weight compounds and inversely, a negative gradient for the highest ones. The half-lives in the 0-20-cm soil horizon were 64 days for DEHP and 36 days for BPA. A predictive environmental concentration (PEC) of 0.3 μg g(-1) dw was estimated for DEHP, while the experimental value was 0.16 μg g(-1) dw, suggesting degradation processes in soil and/or formation of non-extractable residues. Comparisons of contamination levels for soils from different origins (urban, rural, agricultural, and forest) showed that the urban soil remained the most contaminated one, prior to the agricultural soil after treatment.

  3. Fate of phthalates and BPA in agricultural and non-agricultural soils of the Paris area (France).

    PubMed

    Tran, Bich Chau; Teil, Marie-Jeanne; Blanchard, Martine; Alliot, Fabrice; Chevreuil, Marc

    2015-07-01

    This study (i) investigated the concentration levels of nine phthalates and bisphenol A (BPA) in sludge samples originating from a French wastewater treatment plant (WWTP), (ii) studied the distribution of target compounds according to soil depth and calculated their half-lives, and (iii) compared the contamination level of the agricultural soil with those of soils with other land uses. The sludge contamination levels varied from a few hundred nanograms per gram dry weight (dw) for diethyl phthalate (DEP), di-iso-butyl phthalate (DiBP), di-n-butyl phthalate (DnBP), and butyl-benzyl phthalate (BBP) to a few micrograms per gram dw for diethylhexyl phthalate (DEHP), di-iso-nonyl phthalate (DiNP), and di-iso-decyl phthalate (DiDP). After sludge application, an 8-fold increase for DEHP level and a 3-fold increase for BPA level occurred in the surface horizon of the soil. The mean distribution of phthalates according to the depth showed a positive gradient for the low molecular weight compounds and inversely, a negative gradient for the highest ones. The half-lives in the 0-20-cm soil horizon were 64 days for DEHP and 36 days for BPA. A predictive environmental concentration (PEC) of 0.3 μg g(-1) dw was estimated for DEHP, while the experimental value was 0.16 μg g(-1) dw, suggesting degradation processes in soil and/or formation of non-extractable residues. Comparisons of contamination levels for soils from different origins (urban, rural, agricultural, and forest) showed that the urban soil remained the most contaminated one, prior to the agricultural soil after treatment. PMID:25794574

  4. Ancient Agricultural Terraces and the Soil Erosion Paradox

    NASA Astrophysics Data System (ADS)

    Brown, Tony

    2015-04-01

    Geoarchaeology lies at the heart of debates about societal stability and change. Geomorphological research has been used as a foundation for simplistic models of resource depletion based almost entirely on the comparison of soil erosion rates with long-term so- called 'geological' rates. However, the neo-catastrophic collapse of complex agricultural societies is rare, and where it is convincing demonstrated it is even more rarely monocausal. Indeed many societies appear to have continued agricultural exploitation of climatically marginal lands for far longer than soil depletion estimates would forecast. One reason may be that this soil depletion approach has grossly simplified soil creation through weathering, and neglected how past agriculture also affected the soil creation rate (especially on some lithologies) and how soil was conserved (terraces) and utilised even after transport. However, we now have we know have some potentially valuable new tools, including mineral magnetics and cosmogenic nuclides, which can be used to estimate changing soil weathering rates. This approach will be discussed with examples from both the temperate and Mediterranean climatic zones and in relation to causative models of change in complex agricultural societies.

  5. Phenylurea herbicide sorption to biochars and agricultural soil

    PubMed Central

    WANG, DAOYUAN; MUKOME, FUNGAI N. D.; YAN, DENGHUA; WANG, HAO; SCOW, KATE M.; PARIKH, SANJAI J.

    2016-01-01

    Biochar is increasingly been used as a soil amendment to improve water holding capacity, reduce nutrient leaching, increase soil pH and also as a means to reduce contamination through sorption of heavy metals or organic pollutants. The sorption behavior of three phenylurea herbicides (monuron, diuron, linuron) on five biochars (Enhanced Biochar, Hog Waste, Turkey Litter, Walnut Shell and Wood Feedstock) and an agricultural soil (Yolo silt loam) was investigated using a batch equilibration method. Sorption isotherms of herbicides to biochars were well described by the Freundlich model (R2 = 0.93 -- 0.97). The adsorption KF values ranged from 6.94 to 1306.95 mg kg−1 and indicated the sorption of herbicides in the biochars and Yolo soil was in the sequence of linuron > diuron > monuron and walnut shell biochar > wood feedstock biochar > turkey litter biochar > enhanced biochar > hog waste biochar > Yolo soil. These data show that sorption of herbicides to biochar can have both positive (reduced off-site transport) and negative (reduced herbicide efficacy) implications and specific biochar properties, such as H/C ratio and surface area, should be considered together with soil type, agriculture chemical and climate condition in biochar application to agricultural soil to optimize the system for both agricultural and environmental benefits. PMID:26065514

  6. Phenylurea herbicide sorption to biochars and agricultural soil.

    PubMed

    Wang, Daoyuan; Mukome, Fungai N D; Yan, Denghua; Wang, Hao; Scow, Kate M; Parikh, Sanjai J

    2015-01-01

    Biochar is increasingly been used as a soil amendment to improve water-holding capacity, reduce nutrient leaching, increase soil pH, and also as a means to reduce contamination through sorption of heavy metals or organic pollutants. The sorption behavior of three phenylurea herbicides (monuron, diuron and linuron) on five biochars (Enhanced Biochar, Hog Waste, Turkey Litter, Walnut Shell and Wood Feedstock) and an agricultural soil (Yolo silt loam) was investigated using a batch equilibration method. Sorption isotherms of herbicides to biochars were well described by the Freundlich model (R(2) = 0.93-0.97). The adsorption KF values ranged from 6.94 to 1306.95 mg kg(-1) and indicated the sorption of herbicides in the biochars and Yolo soil was in the sequence of linuron > diuron > monuron and walnut shell biochar > wood feedstock biochar > turkey litter biochar > enhanced biochar > hog waste biochar > Yolo soil. These data show that sorption of herbicides to biochar can have both positive (reduced off-site transport) and negative (reduced herbicide efficacy) implications and specific biochar properties, such as H/C ratio and surface area, should be considered together with soil type, agriculture chemical and climate condition in biochar application to agricultural soil to optimize the system for both agricultural and environmental benefits. PMID:26065514

  7. About soil cover heterogeneity of agricultural research stations' experimental fields

    NASA Astrophysics Data System (ADS)

    Rannik, Kaire; Kõlli, Raimo; Kukk, Liia

    2013-04-01

    Depending on local pedo-ecological conditions (topography, (geo) diversity of soil parent material, meteorological conditions) the patterns of soil cover and plant cover determined by soils are very diverse. Formed in the course of soil-plant mutual relationship, the natural ecosystems are always influenced to certain extent by the other local soil forming conditions or they are site specific. The agricultural land use or the formation of agro-ecosystems depends foremost on the suitability of soils for the cultivation of feed and food crops. As a rule, the most fertile or the best soils of the area, which do not present any or present as little as possible constraints for agricultural land use, are selected for this purpose. Compared with conventional field soils, the requirements for the experimental fields' soil cover quality are much higher. Experimental area soils and soil cover composition should correspond to local pedo-ecological conditions and, in addition to that, represent the soil types dominating in the region, whereas the fields should be as homogeneous as possible. The soil cover heterogeneity of seven arable land blocks of three research stations (Jõgeva, Kuusiku and Olustvere) was studied 1) by examining the large scale (1:10 000) digital soil map (available via the internet), and 2) by field researches using the transect method. The stages of soils litho-genetic and moisture heterogeneities were estimated by using the Estonian normal soils matrix, however, the heterogeneity of top- and subsoil texture by using the soil texture matrix. The quality and variability of experimental fields' soils humus status, was studied more thoroughly from the aspect of humus concentration (g kg-1), humus cover thickness (cm) and humus stocks (Mg ha-1). The soil cover of Jõgeva experimental area, which presents an accumulative drumlin landscape (formed during the last glacial period), consist from loamy Luvisols and associated to this Cambisols. In Kuusiku area

  8. Bioremediation of PAH contaminated soil samples

    SciTech Connect

    Joshi, M.M.; Lee, S.

    1994-12-31

    Soils contaminated with polynuclear aromatic hydrocarbons (PAHs) pose a hazard to life. The remediation of such sites can be done using physical, chemical, and biological treatment methods or a combination of them. It is of interest to study the decontamination of soil using bioremediation. The experiments were conducted using Acinetobacter (ATCC 31012) at room temperature without pH or temperature control. In the first series of experiments, contaminated soil samples obtained from Alberta Research Council were analyzed to determine the toxic contaminant and their composition in the soil. These samples were then treated using aerobic fermentation and removal efficiency for each contaminant was determined. In the second series of experiments, a single contaminant was used to prepare a synthetic soil sample. This sample of known composition was then treated using aerobic fermentation in continuously stirred flasks. In one set of flasks, contaminant was the only carbon source and in the other set, starch was an additional carbon source. In the third series of experiments, the synthetic contaminated soil sample was treated in continuously stirred flasks in the first set and in fixed bed in the second set and the removal efficiencies were compared. The removal efficiencies obtained indicated the extent of biodegradation for various contaminants, the effect of additional carbon source, and performance in fixed bed without external aeration.

  9. Proximal Soil Sensing – A Contribution for Species Habitat Distribution Modelling of Earthworms in Agricultural Soils?

    PubMed Central

    Schirrmann, Michael; Joschko, Monika; Gebbers, Robin; Kramer, Eckart; Zörner, Mirjam; Barkusky, Dietmar; Timmer, Jens

    2016-01-01

    Background Earthworms are important for maintaining soil ecosystem functioning and serve as indicators of soil fertility. However, detection of earthworms is time-consuming, which hinders the assessment of earthworm abundances with high sampling density over entire fields. Recent developments of mobile terrestrial sensor platforms for proximal soil sensing (PSS) provided new tools for collecting dense spatial information of soils using various sensing principles. Yet, the potential of PSS for assessing earthworm habitats is largely unexplored. This study investigates whether PSS data contribute to the spatial prediction of earthworm abundances in species distribution models of agricultural soils. Methodology/Principal Findings Proximal soil sensing data, e.g., soil electrical conductivity (EC), pH, and near infrared absorbance (NIR), were collected in real-time in a field with two management strategies (reduced tillage / conventional tillage) and sandy to loam soils. PSS was related to observations from a long-term (11 years) earthworm observation study conducted at 42 plots. Earthworms were sampled from 0.5 x 0.5 x 0.2 m³ soil blocks and identified to species level. Sensor data were highly correlated with earthworm abundances observed in reduced tillage but less correlated with earthworm abundances observed in conventional tillage. This may indicate that management influences the sensor-earthworm relationship. Generalized additive models and state-space models showed that modelling based on data fusion from EC, pH, and NIR sensors produced better results than modelling without sensor data or data from just a single sensor. Regarding the individual earthworm species, particular sensor combinations were more appropriate than others due to the different habitat requirements of the earthworms. Earthworm species with soil-specific habitat preferences were spatially predicted with higher accuracy by PSS than more ubiquitous species. Conclusions/Significance Our

  10. Monitoring soil moisture dynamics via ground-penetrating radar survey of agriculture fields after irrigation

    NASA Astrophysics Data System (ADS)

    Muro, G.

    2015-12-01

    It is possible to examine the quality of ground-penetrating radar (GPR) as a measure of soil moisture content in the shallow vadose zone, where roots are most abundant and water conservation best management practices are critical in active agricultural fields. By analyzing temporal samplings of 100 Mhz reflection profiles and common-midpoint (CMP) soundings over a full growing season, the variability of vertical soil moisture distribution directly after irrigation events are characterized throughout the lifecycle of a production crop. Reflection profiles produce high-resolution travel time data and summed results of CMP sounding data provide sampling depth estimates for the weak, but coherent reflections amid strong point scatterers. The high ratio of clay in the soil limits the resolution of downward propagation of infiltrating moisture after irrigation; synthetic data analysis compared against soil moisture lysimeter logs throughout the profile allow identification of the discrete soil moisture content variation in the measured GPR data. The nature of short duration irrigation events, evapotranspiration, and drainage behavior in relation to root depths observed in the GPR temporal data allow further examination and comparison with the variable saturation model HYDRUS-1D. After retrieving soil hydraulic properties derived from laboratory measured soil samples and simplified assumptions about boundary conditions, the project aims to achieve good agreement between simulated and measured soil moisture profiles without the need for excessive model calibration for GPR-derived soil moisture estimates in an agricultural setting.

  11. Lunar base agriculture: Soils for plant growth

    NASA Technical Reports Server (NTRS)

    Ming, Douglas W. (Editor); Henninger, Donald L. (Editor)

    1989-01-01

    This work provides information on research and experimentation concerning various aspects of food production in space and particularly on the moon. Options for human settlement of the moon and Mars and strategies for a lunar base are discussed. The lunar environment, including the mineralogical and chemical properties of lunar regolith are investigated and chemical and physical considerations for a lunar-derived soil are considered. It is noted that biological considerations for such a soil include controlled-environment crop production, both hydroponic and lunar regolith-based; microorganisms and the growth of higher plants in lunar-derived soils; and the role of microbes to condition lunar regolith for plant cultivation. Current research in the controlled ecological life support system (CELSS) project is presented in detail and future research areas, such as the growth of higher research plants in CELSS are considered. Optimum plant and microbiological considerations for lunar derived soils are examined.

  12. Actinide recovery method -- Large soil samples

    SciTech Connect

    Maxwell , S.L. III

    2000-04-25

    There is a need to measure actinides in environmental samples with lower and lower detection limits, requiring larger sample sizes. This analysis is adversely affected by sample-matrix interferences, which make analyzing soil samples above five-grams very difficult. A new Actinide-Recovery Method has been developed by the Savannah River Site Central Laboratory to preconcentrate actinides from large-soil samples. Diphonix Resin (Eichrom Industries), a 1994 R and D 100 winner, is used to preconcentrate the actinides from large soil samples, which are bound powerfully to the resin's diphosphonic acid groups. A rapid microwave-digestion technique is used to remove the actinides from the Diphonix Resin, which effectively eliminates interfering matrix components from the soil matrix. The microwave-digestion technique is more effective and less tedious than catalyzed hydrogen peroxide digestions of the resin or digestion of diphosphonic stripping agents such as HEDPA. After resin digestion, the actinides are recovered in a small volume of nitric acid which can be loaded onto small extraction chromatography columns, such as TEVA Resin, U-TEVA Resin or TRU Resin (Eichrom Industries). Small, selective extraction columns do not generate large volumes of liquid waste and provide consistent tracer recoveries after soil matrix elimination.

  13. Metals in residential soils and cumulative risk assessment in Yaqui and Mayo agricultural valleys, northern Mexico.

    PubMed

    Meza-Montenegro, Maria M; Gandolfi, A Jay; Santana-Alcántar, María Ernestina; Klimecki, Walter T; Aguilar-Apodaca, María Guadalupe; Del Río-Salas, Rafael; De la O-Villanueva, Margarita; Gómez-Alvarez, Agustín; Mendivil-Quijada, Héctor; Valencia, Martín; Meza-Figueroa, Diana

    2012-09-01

    This investigation examines the extent of soil metal pollution associated with the Green Revolution, relative to agricultural activities and associated risks to health in the most important agricultural region of Mexico. Metal contents in bulk soil samples are commonly used to assess contamination, and metal accumulations in soils are usually assumed to increase with decreasing particle size. This study profiled the spatial distribution of metals (Ni, Cr, Pb, Cu, Fe, Cd, V, Hg, Co, P, Se, and Mn) in bulk soil and fine-grained fractions (soil-derived dust) from 22 towns and cities. The contamination of soil was assessed through the use of a geoaccumulation index (Igeo) and pollution index (PI). The results of this study indicated that a number of towns and cities are moderately to highly polluted by soil containing Be, Co, Hg, P, S, V, Zn, Se, Cr, and Pb in both size fractions (coarse and fine). Hazard index in fine fraction (HI(children)=2.1) shows that risk assessment based on Co, Mn, V, and Ni spatially related to power plants, have the potential to pose health risks to local residents, especially children. This study shows that risk assessment based on metal content in bulk soil could be overestimated when compared to fine-grained fraction. Our results provide important information that could be valuable in establishing risk assessment associated with residential soils within agricultural areas, where children can ingest and inhale dust.

  14. Bioavailability and soil-to-plant transfer factors as indicators of potentially toxic element contamination in agricultural soils.

    PubMed

    Adamo, Paola; Iavazzo, Pietro; Albanese, Stefano; Agrelli, Diana; De Vivo, Benedetto; Lima, Annamaria

    2014-12-01

    Soil pollution in agricultural lands poses a serious threat to food safety, and suggests the need for consolidated methods providing advisory indications for soil management and crop production. In this work, the three-step extraction procedure developed by the EU Measurement and Testing Programme and two soil-to-plant transfer factors (relative to total and bioavailable concentration of elements in soil) were applied on polluted agricultural soils from southern Italy to obtain information on the retention mechanisms of metals in soils and on their level of translocation to edible vegetables. The study was carried out in the Sarno river plain of Campania, an area affected by severe environmental degradation potentially impacting the health of those consuming locally produced vegetables. Soil samples were collected in 36 locations along the two main rivers flowing into the plain. In 11 sites, lettuce plants were collected at the normal stage of consumption. According to Italian environmental law governing residential soils, and on the basis of soil background reference values for the study area, we found diffuse pollution by Be, Sn and Tl, of geogenic origin, Cr and Cu from anthropogenic sources such as tanneries and intensive agriculture, and more limited pollution by Pb, Zn and V. It was found that metals polluting soils as a result of human activities were mainly associated to residual, oxidizable and reducible phases, relatively immobile and only potentially bioavailable to plants. By contrast, the essential elements Zn and Cu showed a tendency to become more readily mobile and bioavailable as their total content in soil increased and were more easily transported to the edible parts of lettuce than other pollutants. According to our results, current soil pollution in the studied area does not affect the proportion of metals taken up by lettuce plants and there is a limited health risk incurred.

  15. 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)…

  16. Monitoring changes in soil carbon resulting from intensive production, a non-traditional agricultural methodology.

    SciTech Connect

    Dwyer, Brian P.

    2013-03-01

    New Mexico State University and a group of New Mexico farmers are evaluating an innovative agricultural technique they call Intensive Production (IP). In contrast to conventional agricultural practice, IP uses intercropping, green fallowing, application of soil amendments and soil microbial inocula to sequester carbon as plant biomass, resulting in improved soil quality. Sandia National Laboratories role was to identify a non-invasive, cost effective technology to monitor soil carbon changes. A technological review indicated that Laser Induced Breakdown Spectroscopy (LIBS) best met the farmers objectives. Sandia partnered with Los Alamos National Laboratory (LANL) to analyze farmers test plots using a portable LIBS developed at LANL. Real-time LIBS field sample analysis was conducted and grab samples were collected for laboratory comparison. The field and laboratory results correlated well implying the strong potential for LIBS as an economical field scale analytical tool for analysis of elements such as carbon, nitrogen, and phosphate.

  17. Geogenic and agricultural controls on the geochemical composition of European agricultural soils

    NASA Astrophysics Data System (ADS)

    Mol, Gerben; Saaltink, Remon; Griffioen, Jasper; Birke, Manfred

    2014-05-01

    Purpose: Concern about the environmental impact of agriculture caused by intensification is growing as large amounts of nutrients and contaminants are introduced into the environment. The aim of this paper is to identify the geogenic and agricultural controls on the elemental composition of European, grazing and agricultural soils. Materials and methods: Robust factor analysis was applied to data series for Al,B,Ca, Cd,Co, Cu, Fe, K, Mg,Mn, Na,Ni, P, S, Se, Sr, U, Zn (ICP-MS) and SiO2, K2O, Na2O, Fe2O3, Al2O3 (XRF) based on the European GEMAS dataset. In addition, the following general soil properties were included: clay content, pH, chemical index of alteration (CIA), loss on ignition (LOI), cation exchange capacity (CEC), total organic carbon (TOC) and total carbon and total sulfur. Furthermore, this dataset was coupled to a dataset containing information of historic P2O5 fertilization across Europe. Also, a mass balance was carried out for Cd, Cu and Zn to determine if concentrations of these elements found in the soils have their origin in historic P2O5 fertilization. Results and discussion: Seven geogenic factors and one agricultural factor were found of which four prominent ones (all geogenic): chemical weathering, reactive iron-aluminum oxide minerals, clay minerals and carbonate minerals. Results for grazing and agricultural soils were near identical, which further proofs the prominence of geogenic controls on the total elemental composition. When the cumulative amount of P2O5 fertilization was considered, no extra agriculture-related factors became visible. The mass balance confirms these observations. Conclusion: Overall, the geological controls are more important for the total soil chemistry in agricultural and grazing land soils than the anthropogenic controls.

  18. Characterizing phosphorus in environmental and agricultural samples by 31P nuclear magnetic resonance spectroscopy.

    PubMed

    Cade-Menun, Barbara J

    2005-04-15

    Phosphorus nuclear magnetic resonance ((31)P-NMR) spectroscopy has advanced our knowledge of organic phosphorus (P) in soils and environmental samples more than any other technique. This paper reviews the use of (31)P-NMR spectroscopy for soil, water and other environmental samples. The requirements for a successful solid-state or solution (31)P-NMR experiment are described, including experimental set-up, sample preparation, extractants, experimental conditions, and post-experimental processing. Next, the literature on solid-state and solution (31)P-NMR spectroscopy in environmental samples is reviewed, including papers on: methods; P transformations; agricultural, forest and natural ecosystem soil studies; humic acid and particle size separations; manure, compost and sludge studies; and water research, including freshwater, estuary and marine studies. Future research needs are also discussed as well as suggestions to improve results, such as increased standardization among research groups.

  19. Sorption and transport of atrazine in an agricultural soil

    NASA Astrophysics Data System (ADS)

    Hakan Akyol, Nihat

    2014-05-01

    Sorption and transport of atrazine in an agricultural soil Atrazine is one of the most commonly used herbicides in large quantity worldwide. The objective of this study was to perform some batch and column experiments to examine the transport of atrazine in an agricultural soil from Turkey. Batch experiments indicated that sorption isotherm was nonlinear with a freundlich isotherm over a range of concentration (0.2-10 mg/L) examined. Column experiments showed that transport of atrazine in the soil was moderately retarded compared to non-reactive tracer (R = 2.9-4.0). The degree of retardation decreased with increasing atrazine concentration and residance time had negligable impact on degree of sorption. Flow interruption tests in the column experiments indicated that the rate-limited desorption of atrazine mainly controlled the non-ideal transport of atrazine due to the presence of organic matter fraction (0.83 %) in the soil. Sorption and desorption behavior of atrazine in such soils could have important impacts for risk assessment of atrazine-contaminated soil and should be taken into account in the regulation, management, and remediation of atrazine-contaminated sites. Keywords: Atrazine, Agricultural soil, Batch, Column, Desorption, Rate-limited desorption, Sorption, Transport.

  20. Formative pre-Hispanic agricultural soils in northwest Argentina

    NASA Astrophysics Data System (ADS)

    Sampietro Vattuone, María Marta; Roldán, Jimena; Neder, Liliana; Maldonado, Mario Gabriel; Vattuone, Marta Amelia

    2011-01-01

    Our study area is from an early agricultural archaeological site named "El Tolar" (1st to 9th century AD), located in Tafí Valley (Tucumán, northwest Argentina). The objective was to identify geochemical signatures generated by the sustained agrarian use of soils. Chemical and pedological studies were made in different archaeological contexts. Physical and chemical features, such as bulk density, pH, organic and inorganic phosphorus, and available copper, manganese and iron, were taken into account. The results suggested that a buried paleosol identified was contemporary with the occupation of the site. It also showed characteristics clearly related to pre-Hispanic agrarian production. The concentrations of organic phosphorus and iron in agricultural soils probably reflect the use of fertilizers. The application of geoscience techniques allowed us to obtain important information on their behaviour and socio-economic development. This paper constitutes the first pedogeochemical approach to the study of Argentinean pre-Hispanic agricultural soils.

  1. Investigation of Soil Erosion and Phosphorus Transport within an Agricultural Watershed

    NASA Astrophysics Data System (ADS)

    Klik, A.; Jester, W.; Muhar, A.; Peinsitt, A.; Rampazzo, N.; Mentler, A.; Staudinger, B.; Eder, M.

    2003-04-01

    In a 40 ha agricultural used watershed in Austria, surface runoff, soil erosion and nutrient losses are measured spatially distributed with 12 small erosion plots. Crops during growing season 2002 are canola, corn, sunflower, winter wheat, winter barley, rye, sugar beets, and pasture. Canopy height and canopy cover are observed in 14-day intervals. Four times per year soil water content, shear stress and random roughness of the surface are measured in a 25 x 25 m grid (140 points). The same raster is sampled for soil texture analyses and content of different phosphorus fractions in the 0-10 cm soil depth. Spatially distributed data are used for geostatistical analysis. Along three transects hydrologic conditions of the hillslope position (top, middle, foot) are investigated by measuring soil water content and soil matrix potential. After erosive events erosion features (rills, deposition, ...) are mapped using GPS. All measured data will be used as input parameters for the Limburg Soil Erosion Model (LISEM).

  2. Arbuscular mycorrhizal fungi in soil and roots respond differently to phosphorus inputs in an intensively managed calcareous agricultural soil.

    PubMed

    Liu, Wei; Zhang, Yunlong; Jiang, Shanshan; Deng, Yan; Christie, Peter; Murray, Philip J; Li, Xiaolin; Zhang, Junling

    2016-01-01

    Understanding the diversity and community structure of arbuscular mycorrhizal fungi (AMF) is important for potentially optimizing their role in mining phosphorus (P) in agricultural ecosystems. Here, we conduct a comprehensive study to investigate the vertical distribution of AMF in a calcareous field and their temporal structure in maize-roots with fertilizer P application over a three-year period. The results showed that soil available-P response to P fertilization but maize yields did not. Phosphorus fertilization had no-significant effect on richness of AMF except at greater soil-depths. High P-supply reduced root colonization while optimum-P tended to increase colonization and fungal richness on all sampling occasions. Crop phenology might override P-supply in determining the community composition of active root inhabiting fungi. Significant differences in the community structure of soil AMF were observed between the controls and P treatments in surface soil and the community shift was attributable mainly to available-P, N/P and pH. Vertical distribution was related mainly to soil electrical conductivity and Na content. Our results indicate that the structure of AMF community assemblages is correlated with P fertilization, soil depth and crop phenology. Importantly, phosphorus management must be integrated with other agricultural-practices to ensure the sustainability of agricultural production in salinized soils. PMID:27102357

  3. Arbuscular mycorrhizal fungi in soil and roots respond differently to phosphorus inputs in an intensively managed calcareous agricultural soil

    PubMed Central

    Liu, Wei; Zhang, Yunlong; Jiang, Shanshan; Deng, Yan; Christie, Peter; Murray, Philip J.; Li, Xiaolin; Zhang, Junling

    2016-01-01

    Understanding the diversity and community structure of arbuscular mycorrhizal fungi (AMF) is important for potentially optimizing their role in mining phosphorus (P) in agricultural ecosystems. Here, we conduct a comprehensive study to investigate the vertical distribution of AMF in a calcareous field and their temporal structure in maize-roots with fertilizer P application over a three-year period. The results showed that soil available-P response to P fertilization but maize yields did not. Phosphorus fertilization had no-significant effect on richness of AMF except at greater soil-depths. High P-supply reduced root colonization while optimum-P tended to increase colonization and fungal richness on all sampling occasions. Crop phenology might override P-supply in determining the community composition of active root inhabiting fungi. Significant differences in the community structure of soil AMF were observed between the controls and P treatments in surface soil and the community shift was attributable mainly to available-P, N/P and pH. Vertical distribution was related mainly to soil electrical conductivity and Na content. Our results indicate that the structure of AMF community assemblages is correlated with P fertilization, soil depth and crop phenology. Importantly, phosphorus management must be integrated with other agricultural-practices to ensure the sustainability of agricultural production in salinized soils. PMID:27102357

  4. The carbon balance of U.S. agricultural soils

    NASA Astrophysics Data System (ADS)

    Paustian, K.; Williams, S.

    2001-05-01

    Carbon inputs through crop residues are one of the main determinants of soil carbon levels and carbon sequestration potentials in cropland soils. We estimated C inputs to U.S. agricultural soils at the county level, over the past 100 years, using a variety of agricultural databases and literature sources. Crop acreage and production estimates, available at the county level through the National Agricultural Statistics Service (NASS-USDA), were used to estimate crop residues. Continuous county values exist from circa 1920 to the present. State level data on acreage and yields of several major crops (corn, wheat, oats, etc.) are available from 1866 through the present. Analogous data from NASS and the Agricultural Census on animal type and numbers were used to estimate animal manure inputs. To estimate C inputs from yields, data from over 125 published works were used to determine regression estimates for grain to aboveground residue ratios, root biomass to aboveground biomass ratios, and estimates of root-derived carbon due to exudation and root sloughing. Where possible, the regressions included changes in these ratios through time as a result of the introduction of new cultivars or new cropping practices. Patterns of carbon inputs over time, and their geographic distribution, are compared with the geographic distribution of present-day soil C stocks on agricultural lands derived from soil maps and pedon data. Predictions of the equilibrium C levels that could be attained under the current levels of carbon input to cropland soils are compared for alternative models of soil organic matter kinetics.

  5. Comparative analysis of different measurement techniques for characterizing soil surface roughness in agricultural soils

    NASA Astrophysics Data System (ADS)

    Martinez-Agirre, Alex; Álvarez-Mozos, Jesús; Valle, José Manuel; Rodríguez, Álvaro; Giménez, Rafael

    2016-04-01

    Soil surface roughness can be defined as the variation in soil surface elevations, and as such, it is a key element in hydrology and soil erosion processes. In agricultural soils, roughness is mainly an anthropic factor determined by the type of tillage and management. Roughness is also a property with a high spatial variability, since the same type of tillage can result in surfaces with different roughness depending on the physical characteristics of the soil and atmospheric conditions. In order to quantify roughness and to parameterize its role in different processes, different measurement techniques have been used and several parameters have been proposed in the literature. The objective of this work is to evaluate different measurement techniques and assess their accuracy and suitability for quantifying surface roughness in agricultural soils. With this aim, a comparative analysis of three roughness measurement techniques has been carried out; (1) laser profilometer, (2) convergent photogrammetry and (3) terrestrial laser scanner. Roughness measurements were done in 3 experimental plots (5x5 meters) with different tillage treatments (representing different roughness conditions) obtained with typical agricultural tools. The laser profilometer registered vertically the distance from a reference bar down to the surface. It had a vertical accuracy of 1.25 mm, a sampling interval of 5 mm and a total length profile of 5 m. Eight profiles were taken per plot, four in parallel to tillage direction and four in perpendicular. Convergent photogrammetry consisted of 20-30 images taken per plot from a height of 5-10 m above ground (using an elevation platform), leading to point clouds of ~25 million points per plot. Terrestrial laser scanner measurements were taken from the four sides of each plot at a measurement height of ~1.75 m above ground. After orientating and corregistering the four scans, point clouds of ~60 million points were obtained per plot. The comparative

  6. Electrical Imaging of Infiltration in Agricultural Soils on Long Island, New York

    NASA Astrophysics Data System (ADS)

    Lampousis, A.; Kenyon, P. M.; Sanwald, K.; Steiner, N.

    2007-12-01

    High resolution electrical resistivity imaging of vadose zone infiltration experiments was conducted on agricultural soils by the City College and Graduate Center of CUNY, in cooperation with Cornell University's Agricultural Stewardship Program and Long Island Horticultural Research and Extension Center (LIHREC) in Riverhead, New York. Measurements were made in active vineyards with a commercial resistivity imaging system, using a half- meter electrode spacing. Soils considered were Riverhead sandy loam (RdA), Haven loam (HaA), and Bridgehampton silty loam (BgA). The Riverhead and Haven soils are the most common types found on eastern Long Island. The Bridgehampton is considered the most fertile. Soil samples and measurements of soil compaction were collected at the same time as the geophysical measurements. In addition, remote sensing data were obtained for the three sites and processed to produce normalized difference vegetation index (NDVI) data to evaluate potential correlations between vegetation vigor, soil texture and water migration patterns. Applications of this study include continuous water content monitoring in high value cash crops (precision agriculture). Changes in electrical resistivity during infiltration are clearly visible at all three locations. Preliminary analysis of the results shows correlations of baseline resistivity with particle size distributions and correlations between changes in resistivity during infiltration and soil compaction data. Time-lapse electrical images of the three sites will also be compared with published properties for these soils, including particle size distribution, saturated hydraulic conductivity, available water capacity, and surface texture.

  7. Agriculture, forestry, range, and soils, chapter 2, part C

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The feasibility of using microwave systems in agriculture, forestry, range, and soil moisture measurements was studied. Theory and preliminary results show the feasibility of measuring moisture status in the soil. For vegetational resources, crop identification for inventory and for yield and production estimates is most feasible. Apart from moisture- and water-related phenomena, microwave systems are also used to record structural and spatial data related to crops and forests.

  8. Taxonomical and functional microbial responses to agriculture management of Amazon forest soils

    NASA Astrophysics Data System (ADS)

    Kuramae, Eiko; Navarrete, Acácio; Mendes, Lucas; de Hollander, Mattias; van Veen, Johannes; Tsai, Siu

    2013-04-01

    Land-use change is one of the greatest threats to biodiversity worldwide, and one of the most devastating changes in the use of land, especially in the tropics, is the conversion of forest to crop lands. Southeast Amazon region is considered the largest agricultural frontier in the world, where native forests are converted into soybean crop fields, a fact that highlights the social and economic importance of this system to Brazil. This study firstly, focused on the impact of land-use changes and agriculture management of Amazon forest soils on the size and composition of the acidobacterial community. Taxon-specific quantitative real-time PCR (qPCR) and pyrosequencing of 16S rRNA gene were applied to study the acidobacterial community in bulk soil samples from croplands, adjacent native forests and rhizosphere of soybean. Based on qPCR measurements, Acidobacteria accounted for 23%, 18% and 14% of the total bacterial signal in forest soils, cropland soils and soybean rhizosphere samples, respectively. From the sequences of Bacteria domain, the phylum Acidobacteria represented 28%, 16% and 17% of the sequences from forest soils, cropland soils and soybean rhizosphere samples, respectively. Acidobacteria subgroups 2-8, 10, 11, 13, 17, 18, 22 and 25 were detected with subgroup 1 as dominant among them. Subgroups 4, 6 and 7 were significantly higher in cropland soils than in forest soils, which subgroups respond to decrease of soil Aluminium. Subgroups 6 and 7 respond to high content of soil Ca, Mg, Zn, P, Fe, Mn and B. The results showed differential response of the Acidobacteria subgroups to abiotic soil factors, and indicated acidobacterial subgroups as potential early-warning bio-indicators of agricultural soil management effects in the Amazon area. Secondly, using 454 pyrosequencing, we investigated the metabolic diversity of microbial communities colonizing the rhizosphere and the bulk soil associated to soybean. The rhizosphere presented an overrepresentation of

  9. Quantification Of Erosion Rates Of Agriculturally Used Soils By Artificial

    NASA Astrophysics Data System (ADS)

    Jha, Abhinand

    2010-05-01

    for 137Cs and 53 days for 7Be), delivery rates, delivery histories, and land use (Fig. 2). An Physical processes, such as water and wind, are the dominant factors moving 137Cs, 7Be tagged soil particles within and between landscape compartments. PIC Figure 2: Generalized sketch illustrating the distributions of 137Cs and 7Be in tilled and undisturbed soils 2 Erosion study at Young Moraine regions of Germany Recently, a study had been performed to evaluate erosion rates in a typical pattern of landscapes in the Young Moraine regions of North-East Germany [5]. The 137Cs concentrations were measured at selected sampling points of various study sites. Among the areas selected for sampling was Basedow, which is a cultivated area, situated north of Berlin. During a master thesis study at university of Bremen in the academic year 2008-2009 [6] a second sampling campaign was performed at the same study site and 137Cs and 7Be concentrations were measured. Two mathematical models (a proportional model and a mass balance model) were applied to estimate erosion or deposition rates giving a distinction between uncultivated or essentially undisturbed soils and cultivated or soils under permanent pasture (Fig.3A). An improved depositional model was developed during this study. The simulation results from this model are presented in Fig.4. Due to the half-life (53.2 days) of 7Be, a mass balance model was developed and used to calculate erosion rates from 7Be (Fig.3B). PIC Figure 3: A: Erosion rates for 137Cs calculated by mass balance model. B: Erosion rates calculated with mass balance model using the 7Be data at Basedow (2008). The results verify that there is long term erosion as a result of wind, water and agricultural practices. The annual erosion rates at Basedow calculated using a mass balance and a proportional model were in the range between 30-50 t ha-1yr-1. These values were comparable to the erosion rates calculated in the previous study [5] by the models mentioned above

  10. Ibuprofen adsorption in four agricultural volcanic soils.

    PubMed

    Estevez, Esmeralda; Hernandez-Moreno, Jose Manuel; Fernandez-Vera, Juan Ramon; Palacios-Diaz, Maria Pino

    2014-01-15

    Ibuprofen (IB) is a high environmental risk drug and one of the most frequently prescribed in human medicine. Recently, IB has been detected in Gran Canaria in reclaimed water for irrigation and in groundwater. Adsorption was studied in four volcanic soils from three islands of the Canarian Archipelago. Once the biodegradation process has been excluded from the experimental conditions, a batch method was applied using initial concentrations of 1-5-10-20-50-100-200 mg L(-1) and two soil/water ratios (w/V): 1:5 (OECD, 2000) and 1:1. Non-linear and linearized Langmuir and Freundlich equations were well fitted. The wide IB range tested in our batch studies allowed us to measure experimental adsorption values close to the maximum adsorption capacity (S(max)) as estimated by Langmuir, making it possible thereby to validate the use of the Langmuir equation when there is a burst of contamination at high concentration. The distribution coefficient (Kd), S(max) and Retardation Factor (RF) varied from 0.04 to 0.5 kg L(-1), 4-200 mgk g(-1) and 1.2-1.9, respectively. The lowest S(max) and Kd values were found for the 1:1S/W ratio whereas most batch studies employ 1:5S/W ratios, thus obtaining higher adsorption parameters than when considering field conditions (1:1). Despite the high anion retention of andic soils, similar Kd and RF to those reported for other soils were obtained in 1:5, while high S(max) was found. Our results demonstrate that IB adsorption in volcanic areas responds not only to the soil properties commonly cited in adsorption studies, but also depends on andic properties, sorbent concentration and Dissolved Organic Carbon, the higher values of which are related to the lower Kd and S(max). The low RF and low detection frequency of the IB in groundwater suggests that a) reclaimed water irrigation is not the main source of IB, and b) the existence of some uncontrolled water disposal points in the zone.

  11. Carbon isotope fractionation of methyl bromide during agricultural soil fumigations

    USGS Publications Warehouse

    Bill, M.; Miller, L.G.; Goldstein, Allen H.

    2002-01-01

    The isotopic composition of methyl bromide (CH3Br) has been suggested to be a potentially useful tracer for constraining the global CH3Br budget. In order to determine the carbon isotopic composition of CH3Br emitted from the most significant anthropogenic application (pre-plant fumigation) we directly measured the ??13C of CH3Br released during commercial fumigation. We also measured the isotopic fractionation associated with degradation in agricultural soil under typical field fumigation conditions. The isotopic composition of CH3Br collected in soil several hours after injection of the fumigant was -44.5??? and this value increased to -20.7??? over the following three days. The mean kinetic isotope effect (KIE) associated with degradation of CH3Br in agricultural soil (12???) was smaller than the reported value for methylotrophic bacterial strain IMB-1, isolated from previously fumigated agricultural soil, but was similar to methylotrophic bacterial strain CC495, isolated from a pristine forest litter zone. Using this fractionation associated with the degradation of CH3Br in agricultural soil and the mean ??13C of the industrially manufactured CH3Br (-54.4???), we calculate that the agricultural soil fumigation source has a carbon isotope signature that ranges from -52.8??? to -42.0???. Roughly 65% of industrially manufactured CH3Br is used for field fumigations. The remaining 35% is used for structural and post-harvest fumigations with a minor amount used during industrial chemical manufacturing. Assuming that the structural and post-harvest fumigation sources of CH3Br are emitted without substantial fractionation, we calculate that the ??13C of anthropogenically emitted CH3Br ranges from -53.2??? to -47.5???.

  12. Persistence and Viability of Lecanicillium lecanii in Chinese Agricultural Soil

    PubMed Central

    Peng, De-Liang; Zhou, Jie; Zhang, Xiao-Lin; Zhang, Zhao-Rong; Zhao, Jin-Jin; Wu, Yu-Huan

    2015-01-01

    The entomopathogenic fungus L. lecanii has been developed as biopesticides and used widely for biological control of several insects in agricultural practice. Due to the lack of isolation/count methods for L. lecanii in soil, the persistence of this fungus in soil appears to have attracted no attention. A selective medium and count method for L. lecanii in soil based on cetyl trimethyl ammonium bromide (CTAB) was developed, and then the persistence and viability of this fungus in soil were investigated under field conditions between 2012 and 2014. The results showed that the rate of recovery for L. lecanii in soil on the selective CTAB medium was satisfactory. The minimum CFUs for L. lecanii on the selective medium (0.5 g/L CTAB) was about 102 conidia/g soil. The L. lecanii density in soil declined quickly in the first month after inoculation with fungal conidia, kept stable for 6 to 10 months, and then decreased gradually until undetectable. L. lecanii could persist for at least 14 months in the agricultural soil of northern China. The colony growth, conidia yield and germination rate on plates, as well as the median lethal concentration or times (LC50 or LT50) to aphids, mycelium growth in aphids and sporulation on aphids of L. lecanii did not change significantly during the persistence in soil. In general, the count method developed here was a very useful tool for monitoring the dynamics of natural or introduced L. lecanii populations in soil, and the data on the persistence of L. lecanii in soil reported here were helpful for biological control and environmental risk assessment. PMID:26375030

  13. Is current biochar soil study addressing global soil constraints for sustainable agriculture?

    NASA Astrophysics Data System (ADS)

    Pan, Genxing; Zhang, Dengxiao; Yan, Ming; Niu, Yaru; Liu, Xiaoyu; van Zwieten, Lukas; Chen, De; Bian, Rongjun; Cheng, Kun; Li, Lianqing; Joseph, Stephen; Zheng, Jinwei; Zhang, Xuhui; Zheng, Jufeng; Crowley, David; Filley, Timothy

    2016-04-01

    Global soil degradation has been increasingly threatened sustainability of world agriculture. Use of biochar from bio-wastes has been proposed as a global option for its great potential in tackling soil degradation and mitigating climate change in agriculture. For last 10 years, there have been greatly increasing interests in application of charred biomass, more recently termed biochar, as a soil amendment for addressing soil constraints for sustainable agriculture. Biochar soil studies could deliver reliable information for appropriate application of biochar to soils where for sustainable agriculture has been challenged. Here we review the literature of 798 publications reporting biochar soil studies by August, 2015 to address potential gaps in understanding of biochar's role in agriculture. We have found some substantial biases and gaps inherent in the current biochar studies. 1) The majority of published studies were from developed regions where the soils are less constrained and were much more frequent in laboratory and glasshouse pot experiments than field studies under realistic agriculture. 2) The published biochar soil studies have used more often small kiln or lab prepared biochar than commercial scale biochars, more often wood and municipal waste derived biochars than crop straw biochars. Overall, the lack of long-term well designed field studies using biochar produced in commercial processes may have limited our current understanding of biochar's potential to enhance global crop production and climate change mitigation. We have also recommended a global alliance between longer-term research experiments and biochar production facilities to foster the uptake of this important technology at a global scale. Keywords: biochar, soil study, literature review, research gap, global perspective, quantitative assessment, sustainable agriculture

  14. COMPOSITE SAMPLING FOR SOIL VOC ANALYSIS

    EPA Science Inventory

    Data published by numerous researchers over the last decade demonstrate that there is a high degree of spatial variability in the measurement of volatile organic compounds (VOCs) in soil at contaminated waste sites. This phenomenon is confounded by the use of a small sample aliqu...

  15. Cesium and strontium sorption behavior in amended agricultural soils

    NASA Astrophysics Data System (ADS)

    Mehmood, Khalid; Hofmann, Diana; Burauel, Peter; Vereecken, Harry; Berns, Anne E.

    2014-05-01

    Biogas digestates and biochar are emerging soil amendments. Biochar is a byproduct of pyrolysis process which is thermal decomposition of biomass to produce syngas and bio-oil. The use of biochar for soil amendment is being promoted for higher crop yields and carbon sequestration. Currently, the numbers of biogas plants in Germany are increasing to meet the new energy scenarios. The sustainability of biogas industry requires proper disposal options for digestate. Biogas digestates being rich in nutrients are beneficial to enhance agricultural productions. Contrary to the agronomical benefits of these organic amendments, their use can influence the mobility and bioavailability of soil contaminants due to nutrients competition and high organic matter content. So far, the impact of such amendments on highly problematic contaminants like radionuclides is not truly accounted for. In the present study, sorption-desorption behavior of cesium and strontium was investigated in three soils of different origin and texture. Two agricultural soils, a loamy sand and a silty soil, were amended with biochar and digestate in separate experiments, with field application rates of 25 Mg/ha and 34 Mg/ha, respectively. For comparison a third soil, a forest soil, was incubated without any amendment. The amendments were mixed into the top 20 cm of the field soils, resulting in final concentrations of 8-9 g biochar/Kg soil and 11-12 g digestate/Kg soil. The soils were incubated for about six months at room temperature. Sorption-desorption experiments were performed with CsCl and SrCl2 after pre-equilibrating the soils with CaCl2 solutions. The amendments with field application rates did not have a significant effect on the relevant soil parameters responsible for the sorption behavior of the two radionuclides. Comparatively, the soil type lead to distinctive differences in sorption-desorption dynamics of the two radionuclides. Cesium showed a higher affinity for silty soil followed by

  16. Electrokinetic treatment of an agricultural soil contaminated with heavy metals.

    PubMed

    Figueroa, Arylein; Cameselle, Claudio; Gouveia, Susana; Hansen, Henrik K

    2016-07-28

    The high organic matter content in agricultural soils tends to complex and retain contaminants such as heavy metals. Electrokinetic remediation was tested in an agricultural soil contaminated with Co(+2), Zn(+2), Cd(+2), Cu(+2), Cr(VI), Pb(+2) and Hg(+2). The unenhanced electrokinetic treatment was not able to remove heavy metals from the soil due to the formation of precipitates in the alkaline environment in the soil section close to the cathode. Moreover, the interaction between metals and organic matter probably limited metal transportation under the effect of the electric field. Citric acid and ethylenediaminetetraacetic acid (EDTA) were used in the catholyte as complexing agents in order to enhance the extractability and removal of heavy metals from soil. These complexing agents formed negatively charged complexes that migrated towards the anode. The acid front electrogenerated at the anode favored the dissolution of heavy metals that were transported towards the cathode. The combined effect of the soil pH and the complexing agents resulted in the accumulation of heavy metals in the center of the soil specimen.

  17. Electrokinetic treatment of an agricultural soil contaminated with heavy metals.

    PubMed

    Figueroa, Arylein; Cameselle, Claudio; Gouveia, Susana; Hansen, Henrik K

    2016-07-28

    The high organic matter content in agricultural soils tends to complex and retain contaminants such as heavy metals. Electrokinetic remediation was tested in an agricultural soil contaminated with Co(+2), Zn(+2), Cd(+2), Cu(+2), Cr(VI), Pb(+2) and Hg(+2). The unenhanced electrokinetic treatment was not able to remove heavy metals from the soil due to the formation of precipitates in the alkaline environment in the soil section close to the cathode. Moreover, the interaction between metals and organic matter probably limited metal transportation under the effect of the electric field. Citric acid and ethylenediaminetetraacetic acid (EDTA) were used in the catholyte as complexing agents in order to enhance the extractability and removal of heavy metals from soil. These complexing agents formed negatively charged complexes that migrated towards the anode. The acid front electrogenerated at the anode favored the dissolution of heavy metals that were transported towards the cathode. The combined effect of the soil pH and the complexing agents resulted in the accumulation of heavy metals in the center of the soil specimen. PMID:27127923

  18. Plumbum contamination detecting model for agricultural soil using hyperspectral data

    NASA Astrophysics Data System (ADS)

    Liu, Xiangnan; Huang, Fang; Wang, Ping

    2008-10-01

    The issue of environmental pollution due to toxic heavy metals in agricultural land has caused worldwide growing concern in recent years. Being one of toxic heavy metals, the accumulation of Plumbum (Pb) may have negative effects on natural and agricultural vegetation growth, yield and quality. It can also constitute short-term and long-term health risks by entering the food chain. In this study, we analyze the relationships between physical and chemical characteristics, biological parameters of soil-vegetation system and hyperspectral spectrum responses systematically. The relation between hyperspectral data and the biological parameters of Pb polluted wheat canopy such as leaf pigments, leaf moisture, cell structure and leaf area index (LAI) are discussed. We detect the changes in the wheat biological parameters and spectral response associated with Pb concentration in soil. To reveal the impact mechanisms of Pb concentration on agricultural soil, six models including chlorophyll-leaf moisture model, chlorophyll-cell structure model, chlorophyll-LAI model, leaf moisture-cell structure model, leaf moisture-LAI model, cell structure- LAI model are explored. We find that changes in Pb concentration present various features in different models. Pb contamination in agricultural soil can be identified and assessed effectively while integrating the characteristics of those developed models.

  19. Phosphorus leaching from agricultural soils of the Delmarva Peninsula, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Leaching of phosphorus (P) mobilizes edaphic and applied sources of P and is a primary pathway of concern in agricultural soils of the Delmarva Peninsula, which defines the eastern boundary of the eutrophic Chesapeake Bay. We evaluated P leaching before and after poultry litter application from inta...

  20. Soil carbon and soil respiration in conservation agriculture with vegetables in Siem Reap, Cambodia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A balance between food production and environmental protection is required to sustainably feed a growing population. The resource saving concept of conservation agriculture aims to achieve this balance through implementing simultaneously three conservation practices; no-till, continuous soil cover, ...

  1. Lead Isotopic Tracing of Coal-Based Anthropogenic Pollution in Agricultural Soils in Jianghan Plain, China

    NASA Astrophysics Data System (ADS)

    Daniel, J. N.; Ying, S.; Zhao, R.; Bu, J.; Gan, Y.; Wang, Y.; Weiss, D. J.; Fendorf, S. E.

    2014-12-01

    The Chinese demand for energy is one of the greatest in the world, and the vast majority of it is generated through coal combustion - a process by which diverse pollutants are released into the atmosphere. Due to the relative proximity of croplands to power plants in much of China, these pollutants can be deposited onto agricultural soils via atmospheric transport. Relative amounts of lead (Pb) isotopes in airborne anthropogenic coal-based contaminants (fly ash) are currently understood. However, contaminants' effects on agricultural soil composition are less clear. We investigate the prevalence of anthropogenic contaminants in cropland soils using lead (Pb) isotope ratios as a tracer. Surface soil samples and deep core samples, taken from Chinese field sites in proximity to a coal combustion plant, undergo an acid extraction process and lead (Pb) isotope concentrations are measured. The results of this study illustrate the extent to which airborne contaminants have entered cropland soils and integrated themselves into the chemical processes at work. They further expand our understanding of the impacts of human coal combustion activities on the biogeochemistry of agricultural soils.

  2. The Impact of Soil Sampling Errors on Variable Rate Fertilization

    SciTech Connect

    R. L. Hoskinson; R C. Rope; L G. Blackwood; R D. Lee; R K. Fink

    2004-07-01

    Variable rate fertilization of an agricultural field is done taking into account spatial variability in the soil’s characteristics. Most often, spatial variability in the soil’s fertility is the primary characteristic used to determine the differences in fertilizers applied from one point to the next. For several years the Idaho National Engineering and Environmental Laboratory (INEEL) has been developing a Decision Support System for Agriculture (DSS4Ag) to determine the economically optimum recipe of various fertilizers to apply at each site in a field, based on existing soil fertility at the site, predicted yield of the crop that would result (and a predicted harvest-time market price), and the current costs and compositions of the fertilizers to be applied. Typically, soil is sampled at selected points within a field, the soil samples are analyzed in a lab, and the lab-measured soil fertility of the point samples is used for spatial interpolation, in some statistical manner, to determine the soil fertility at all other points in the field. Then a decision tool determines the fertilizers to apply at each point. Our research was conducted to measure the impact on the variable rate fertilization recipe caused by variability in the measurement of the soil’s fertility at the sampling points. The variability could be laboratory analytical errors or errors from variation in the sample collection method. The results show that for many of the fertility parameters, laboratory measurement error variance exceeds the estimated variability of the fertility measure across grid locations. These errors resulted in DSS4Ag fertilizer recipe recommended application rates that differed by up to 138 pounds of urea per acre, with half the field differing by more than 57 pounds of urea per acre. For potash the difference in application rate was up to 895 pounds per acre and over half the field differed by more than 242 pounds of potash per acre. Urea and potash differences

  3. A contemporary decennial global sample of changing agricultural field sizes

    NASA Astrophysics Data System (ADS)

    White, E.; Roy, D. P.

    2011-12-01

    In the last several hundred years agriculture has caused significant human induced Land Cover Land Use Change (LCLUC) with dramatic cropland expansion and a marked increase in agricultural productivity. The size of agricultural fields is a fundamental description of rural landscapes and provides an insight into the drivers of rural LCLUC. Increasing field sizes cause a subsequent decrease in the number of fields and therefore decreased landscape spatial complexity with impacts on biodiversity, habitat, soil erosion, plant-pollinator interactions, diffusion of disease pathogens and pests, and loss or degradation in buffers to nutrient, herbicide and pesticide flows. In this study, globally distributed locations with significant contemporary field size change were selected guided by a global map of agricultural yield and literature review and were selected to be representative of different driving forces of field size change (associated with technological innovation, socio-economic conditions, government policy, historic patterns of land cover land use, and environmental setting). Seasonal Landsat data acquired on a decadal basis (for 1980, 1990, 2000 and 2010) were used to extract field boundaries and the temporal changes in field size quantified and their causes discussed.

  4. Effect of organic amendments on quality indexes in an italian agricultural soil

    NASA Astrophysics Data System (ADS)

    Scotti, R.; Rao, M. A.; D'Ascoli, R.; Scelza, R.; Marzaioli, R.; Rutigliano, F. A.; Gianfreda, L.

    2009-04-01

    Intensive agricultural practices can determine a decline in soil fertility which represents the main constraint to agricultural productivity. In particular, the progressive reduction in soil organic matter, without an adequate restoration, may threaten soil fertility and agriculture sustainability. Some soil management practices can improve soil quality by adding organic amendments as alternative to the sole use of mineral fertilizers for increasing plant quality and growth. A large number of soil properties can be used to define changes in soil quality. In particular, although more emphasis has been given in literature to physical and chemical properties, biological properties, strictly linked to soil fertility, can be valid even more sensitive indicators. Among these, soil enzyme activities and microbial biomass may provide an "early warning" of soil quality and health changes. The aim of this work was to study the effect of preventive sterilization treatment and organic fertilization on enzymatic activities (dehydrogenase, arylsulphatase, beta-glucosidase, phosphatase, urease) and microbial biomass C in an agricultural soil under crop rotation. The study was carried out on an agricultural soil sited in Campania region (South Italy). At the beginning of experiment sterilizing treatments to control soilborne pathogens and weeds were performed by solarization and calcium cyanamide addition to soil. Organic fertilization was carried out by adding compost from vegetable residues, ricin seed exhaust (Rigen) and straw, singly or in association. Three samplings were performed at three different stages of crop rotation: I) September 2005, immediately after the treatments; II) December 2005, after a lettuce cycle; III) January 2007, after peppers and lettuce cycles. The soil sampling followed a W scheme, with five sub-samples for each plot. Soils were sieved at 2 mm mesh and air dried to determine physical and chemical properties; in addition a suitable amount of soils

  5. Fate of the antiretroviral drug tenofovir in agricultural soil.

    PubMed

    Al-Rajab, Abdul Jabbar; Sabourin, Lyne; Chapman, Ralph; Lapen, David R; Topp, Edward

    2010-10-15

    Tenofovir (9-(R)-(2-phosphonylmethoxypropyl)-adenine) is an antiretroviral drug widely used for the treatment of human immunodeficiency virus (HIV-1) and Hepatitis B virus (HBV) infections. Tenofovir is extensively and rapidly excreted unchanged in the urine. In the expectation that tenofovir could potentially reach agricultural lands through the application of municipal biosolids or wastewater, and in the absence of any environmental fate data, we evaluated its persistence in selected agricultural soils. Less than 10% of [adenine-8-(14)C]-tenofovir added to soils varying widely in texture (sand, loam, clay loam) was mineralized in a 2-month incubation under laboratory conditions. Tenofovir was less readily extractable from clay soils than from a loam or a sandy loam soil. Radioactive residues of tenofovir were removed from the soil extractable fraction with DT(50)s ranging from 24±2 to 67+22days (first order kinetic model) or 44+9 to 127+55days (zero order model). No extractable transformation products were detectable by HPLC. Tenofovir mineralization in the loam soil increased with temperature (range 4°C to 30°C), and did not occur in autoclaved soil, suggesting a microbial basis. Mineralization rates increased with soil moisture content, ranging from air-dried to saturated. In summary, tenofovir was relatively persistent in soils, there were no extractable transformation products detected, and the response of [adenine-8-(14)C]-tenofovir mineralization to soil temperature and heat sterilization indicated that the molecule was biodegraded by aerobic microorganisms. Sorption isotherms with dewatered biosolids suggested that tenofovir residues could potentially partition into the particulate fraction during sewage treatment. PMID:20800877

  6. Long-term fate of nitrate fertilizer in agricultural soils.

    PubMed

    Sebilo, Mathieu; Mayer, Bernhard; Nicolardot, Bernard; Pinay, Gilles; Mariotti, André

    2013-11-01

    Increasing diffuse nitrate loading of surface waters and groundwater has emerged as a major problem in many agricultural areas of the world, resulting in contamination of drinking water resources in aquifers as well as eutrophication of freshwaters and coastal marine ecosystems. Although empirical correlations between application rates of N fertilizers to agricultural soils and nitrate contamination of adjacent hydrological systems have been demonstrated, the transit times of fertilizer N in the pedosphere-hydrosphere system are poorly understood. We investigated the fate of isotopically labeled nitrogen fertilizers in a three-decade-long in situ tracer experiment that quantified not only fertilizer N uptake by plants and retention in soils, but also determined to which extent and over which time periods fertilizer N stored in soil organic matter is rereleased for either uptake in crops or export into the hydrosphere. We found that 61-65% of the applied fertilizers N were taken up by plants, whereas 12-15% of the labeled fertilizer N were still residing in the soil organic matter more than a quarter century after tracer application. Between 8-12% of the applied fertilizer had leaked toward the hydrosphere during the 30-y observation period. We predict that additional exports of (15)N-labeled nitrate from the tracer application in 1982 toward the hydrosphere will continue for at least another five decades. Therefore, attempts to reduce agricultural nitrate contamination of aquatic systems must consider the long-term legacy of past applications of synthetic fertilizers in agricultural systems and the nitrogen retention capacity of agricultural soils.

  7. Influence of management practices on microbial nitrogen cyclers in agricultural soils

    NASA Astrophysics Data System (ADS)

    García-Orenes, Fuensanta; Morugán-Coronado, Alicia; McMillan, Mary; Pereg, Lily

    2016-04-01

    Agricultural land management has great influences on soil properties, in particular on microbial communities, due to their sensitivity to the perturbations of the soils. This is even more relevant in Mediterranean agricultural areas under semi-arid conditions. The Mediterranean belt is suffering from an intense degradation of its soils due to the millennia of intense land use and due to unsustainable management practices. As a consequence this area is suffering from a depletion of N content. In this work we investigated the effect of several traditional agricultural management practices on specific functional groups related to the nitrogen cycle in the soil. A field experiment was performed with orchard orange trees (citrus sinesis) in Eastern Spain to assess the long-term effects of ploughing with inorganic fertilization (PI) and ecological practices (EP) (chipped pruned branches and weeds as well as manure from sheep and goats) on microbes that can undertake nitrogen fixation and denitrification. Nine samples of soil were taken from every treatment, near the drip irrigation point and in a zone without the influence of drip irrigation (between trees row), and total DNA extracted. DNA samples were stored at minus-20°C to be analysed by qPCR. Microbial populations involved in the N biochemical cycle were analysed by targeted amplification of key functional biomarker genes: the abundance of nifH (nitrogen fixation), nirS, nirK and nosZ (denitrification) detected by quantitative PCR (qPCR) has shown significant differences between treatments with higher abundance of all four genes in soils from ecological agricultural treatments. This may indicate that the ecological treatment created conditions that are more suitable for N cyclers in the soil and a better fertility and quality status of these soils.

  8. Observation of soil moisture variability in agricultural and grassland field soils using a wireless sensor network

    NASA Astrophysics Data System (ADS)

    Priesack, Eckart; Schuh, Max

    2014-05-01

    Soil moisture dynamics is a key factor of energy and matter exchange between land surface and atmosphere. Therefore long-term observation of temporal and spatial soil moisture variability is important in studying impacts of climate change on terrestrial ecosystems and their possible feedbacks to the atmosphere. Within the framework of the network of terrestrial environmental observatories TERENO we installed at the research farm Scheyern in soils of two fields (of ca. 5 ha size each) the SoilNet wireless sensor network (Biogena et al. 2010). The SoilNet in Scheyern consists of 94 sensor units, 45 for the agricultural field site and 49 for the grassland site. Each sensor unit comprises 6 SPADE sensors, two sensors placed at the depths 10, 30 and 50 cm. The SPADE sensor (sceme.de GmbH, Horn-Bad Meinberg Germany) consists of a TDT sensor to estimate volumetric soil water content from soil electrical permittivity by sending an electromagnetic signal and measuring its propagation time, which depends on the soil dielectric properties and hence on soil water content. Additionally the SPADE sensor contains a temperature sensor (DS18B20). First results obtained from the SoilNet measurements at both fields sites will be presented and discussed. The observed high temporal and spatial variability will be analysed and related to agricultural management and basic soil properties (bulk density, soil texture, organic matter content and soil hydraulic characteristics).

  9. Distribution of tetraether lipids in agricultural soils - differentiation between paddy and upland management

    NASA Astrophysics Data System (ADS)

    Mueller-Niggemann, C.; Utami, S. R.; Marxen, A.; Mangelsdorf, K.; Bauersachs, T.; Schwark, L.

    2015-10-01

    Insufficient knowledge of the composition and variation of isoprenoid and branched glycerol dialkyl glycerol tetraethers (GDGTs) in agricultural soils exists, despite of the potential effect of different management types (e.g. soil/water and redox conditions, cultivated plants) on GDGT distribution. Here, we determined the influence of different soil management types on the GDGT composition in paddy (flooded) and adjacent upland (non-flooded) soils, and if available also forest, bushland and marsh soils. To compare the local effects on GDGT distribution patterns, we collected comparable soil samples in various locations from tropical (Indonesia, Vietnam and Philippines) and subtropical (China and Italy) sites. We found that differences in the distribution of isoprenoid GDGTs (iGDGTs) as well as of branched GDGTs (brGDGTs) are predominantly controlled by management type and only secondarily by climatic exposition. In general upland soil had higher crenarchaeol contents than paddy soil, which on the contrary was more enriched in GDGT-0. The GDGT-0 / crenarchaeol ratio was 3-27 times higher in paddy soil and indicates the enhanced presence of methanogenic archaea, which were additionally linked to the number of rice cultivation cycles per year (higher number of cycles was coupled with an increase in the ratio). The TEX86 values were 1.3 times higher in upland, bushland and forest soils than in paddy soils. In all soils brGDGT predominated over iGDGTs, with the relative abundance of brGDGTs increasing from subtropical to tropical soils. Higher BIT values in paddy soils compared to upland soils together with higher BIT values in soil from subtropical climates indicate effects on the amounts of brGDGT through differences in management as well as climatic zones. In acidic soil CBT values correlated well with soil pH. In neutral to alkaline soils, however, no apparent correlation but an offset between paddy and upland managed soils was detected, which may suggest that soil

  10. Comparative Analysis for Polluted Agricultural Soils with Arsenic, Lead, and Mercury in Mexico

    SciTech Connect

    Yarto-Ramirez, Mario; Santos-Santos, Elvira; Gavilan-Garcia, Arturo; Castro-Diaz, Jose; Gavilan-Garcia, Irma Cruz; Rosiles, Rene; Suarez, Sara

    2004-03-31

    The use of mercury in Mexico has been associated with the mining industry of Zacatecas. This activity has polluted several areas currently used for agriculture. The main objective of this study was to investigate the heavy metal concentration (Hg, As and Pb) in soil of Guadalupe Zacatecas in order to justify a further environmental risk assessment in the site. A 2X3 km grid was used for the sampling process and 20 soil samples were taken. The analysis was developed using EPA SW 846: 3050B/6010B method for arsenic and metals and EPA SW 846: 7471A for total mercury. It was concluded that there are heavy metals in agricultural soils used for corn and bean farming. For this it is required to make an environmental risk assessment and a bioavailability study in order to determine if there's a risk for heavy metals bioaccumulation in animals or human beings or metal lixiviation to aquifers.

  11. Urban soils: properties for utilitzation for green infrastructure and urban agriculture

    NASA Astrophysics Data System (ADS)

    Shanskiy, Merrit; Krebstein, Kadri

    2015-04-01

    The human influenced soils in urban areas are of prime importance to human populations. Also, it is becoming a trend that there is large increase in reclaimed lands and new users for old industrial areas. Very often the urban soils are heavily modified by different anthropogenic factors. Therefore, it makes it essential to collect the data and knowledge of urban soils in order to understand better how such soils can be managed, rehabilitated or reconditioned to support green infrastructure or urban agriculture. Although the soil organic carbon (SOC) is the largest carbon stock in terrestrial ecosystems and the carbon sequestration is a widely accepted soil function there is still few studies mapping the carbon stocks in urban areas using digital soil mapping techniques. For urban land-use planning and decision making in a process of green infrastructure sustainable development it is in major importance. The urban soils are often lacking sufficient amount of organic matter but they are degraded (compacted, builded, contaminated by construction debris, graded) making them unsuitable as a growing medium. Therefore, the use of certain green infrastructure practices and the development of urban agriculture can be challenging in an urban environment. The issue of assessing soil quality becomes two-fold: the health of the soil as a growing medium needs to be addressed as well as the possible contamination that may be present. Knowing the development history of a parcel is key to determining what type of soil testing should be done, if any, prior to redevelopment or reuse. For current, pilot scale study the soil sampling was carried out in Tartu, Estonia. The different microenvironments were determined inside of urban areas. Soils were collected from such a microenvironments as urban garden areas, parks, other green infrastructure elements. The soils were analyzed for main agrochemical and physical properties at the Estonian University of Life Sciences, laboratory of the

  12. Gamma-spectrometric measurement of radioactivity in agricultural soils of the Lombardia region, northern Italy.

    PubMed

    Guidotti, Laura; Carini, Franca; Rossi, Riccardo; Gatti, Marina; Cenci, Roberto M; Beone, Gian Maria

    2015-04-01

    This work is part of a wider monitoring project of the agricultural soils in Lombardia, which aims to build a database of topsoil properties and the potentially toxic elements, organic pollutants and gamma emitting radionuclides that the topsoils contain. A total of 156 agricultural soils were sampled according to the LUCAS (Land Use/Cover Area frame statistical Survey) standard procedure. The aim was to provide a baseline to document the conditions present at the time of sampling. The results of the project concerning soil radioactivity are presented here. The aim was to assess the content of (238)U, (232)Th, (137)Cs and (40)K by measuring soil samples by gamma spectrometry. (238)U, (232)Th and (40)K activities range 24-231, 20-70, and 242-1434 Bq kg(-1) respectively. The geographic distribution of (238)U reflects the geophysical framework of the Lombardia region: the soils with high content of uranium are distributed for the most part in the South Alpine belt, where the presence of magmatic rocks is widespread. These soils show an higher activity of (238)U than of (232)Th. The (238)U activities become lower than (232)Th when soils are located in the plain, originating from basic sedimentary rocks. (137)Cs activity ranges 0.4-86.8 kBq m(-2). The lowest activity of (137)Cs is in the plain, whereas the highest is in the North on soils kept as lawn or pasture. The (137)Cs activity of some samples suggests the presence of accumulation processes that lead to (137)Cs enriched soils. This is the first survey of gamma emitting radionuclides in Lombardia that is based on the LUCAS standard sampling. The results from this monitoring campaign are important for the human radiation exposure and provide the zero point, which will be useful for assessing future effects due to external factors such as human activities. PMID:25636137

  13. Gamma-spectrometric measurement of radioactivity in agricultural soils of the Lombardia region, northern Italy.

    PubMed

    Guidotti, Laura; Carini, Franca; Rossi, Riccardo; Gatti, Marina; Cenci, Roberto M; Beone, Gian Maria

    2015-04-01

    This work is part of a wider monitoring project of the agricultural soils in Lombardia, which aims to build a database of topsoil properties and the potentially toxic elements, organic pollutants and gamma emitting radionuclides that the topsoils contain. A total of 156 agricultural soils were sampled according to the LUCAS (Land Use/Cover Area frame statistical Survey) standard procedure. The aim was to provide a baseline to document the conditions present at the time of sampling. The results of the project concerning soil radioactivity are presented here. The aim was to assess the content of (238)U, (232)Th, (137)Cs and (40)K by measuring soil samples by gamma spectrometry. (238)U, (232)Th and (40)K activities range 24-231, 20-70, and 242-1434 Bq kg(-1) respectively. The geographic distribution of (238)U reflects the geophysical framework of the Lombardia region: the soils with high content of uranium are distributed for the most part in the South Alpine belt, where the presence of magmatic rocks is widespread. These soils show an higher activity of (238)U than of (232)Th. The (238)U activities become lower than (232)Th when soils are located in the plain, originating from basic sedimentary rocks. (137)Cs activity ranges 0.4-86.8 kBq m(-2). The lowest activity of (137)Cs is in the plain, whereas the highest is in the North on soils kept as lawn or pasture. The (137)Cs activity of some samples suggests the presence of accumulation processes that lead to (137)Cs enriched soils. This is the first survey of gamma emitting radionuclides in Lombardia that is based on the LUCAS standard sampling. The results from this monitoring campaign are important for the human radiation exposure and provide the zero point, which will be useful for assessing future effects due to external factors such as human activities.

  14. Dynamics of arsenic in agricultural soils irrigated with arsenic contaminated groundwater in Bangladesh.

    PubMed

    Saha, Ganesh Chandra; Ali, M Ashraf

    2007-07-01

    Arsenic (As) concentrations in the soil layers of 12 rice fields located in four As affected areas and two unaffected areas in Bangladesh were monitored during 2003. In the unaffected areas, where irrigation water contained little As (<1 microg/L), As concentrations of rice field soils ranged from 1.5 to 3.0 mg/kg and did not vary significantly with either depth or sampling time throughout the irrigation period. In the As affected areas where the irrigation water contained elevated As (79 to 436 microg/L), As concentrations of rice field soils were much higher compared to those in the unaffected areas and varied significantly with both depth and sampling time. For the top 0 to 150 mm of the soil, the As concentration increased significantly at the end of the irrigation season (May-June 2003). About 71% of the As that is applied to the rice field with irrigation water accumulates in the top 0 to 75 mm soil layer by the end of the irrigation season. After the wet season during which the rice fields were inundated with flood/rain water, the As concentrations in the soil layer decreased significantly and were reduced to levels comparable to those found in soil samples collected at the beginning of the irrigation period. The long-term As accumulation in agricultural soil appears to be counteracted by biogeochemical pathways leading to As removal from soil.

  15. Sample storage for soil enzyme activity and bacterial community profiles.

    PubMed

    Wallenius, K; Rita, H; Simpanen, S; Mikkonen, A; Niemi, R M

    2010-04-01

    Storage of samples is often an unavoidable step in environmental data collection, since available analytical capacity seldom permits immediate processing of large sample sets needed for representative data. In microbiological soil studies, sample pretreatments may have a strong influence on measurement results, and thus careful consideration is required in the selection of storage conditions. The aim of this study was to investigate the suitability of prolonged (up to 16 weeks) frozen or air-dried storage for divergent soil materials. The samples selected to this study were mineral soil (clay loam) from an agricultural field, humus from a pine forest and compost from a municipal sewage sludge composting field. The measured microbiological parameters included functional profiling with ten different hydrolysing enzyme activities determined by artificial fluorogenic substrates, and structural profiling with bacterial 16S rDNA community fingerprints by amplicon length heterogeneity analysis (LH-PCR). Storage of samples affected the observed fluorescence intensity of the enzyme assay's fluorophor standards dissolved in soil suspension. The impact was highly dependent on the soil matrix and storage method, making it important to use separate standardisation for each combination of matrix type, storage method and time. Freezing proved to be a better storage method than air-drying for all the matrices and enzyme activities studied. The effect of freezing on the enzyme activities was small (<20%) in clay loam and forest humus and moderate (generally 20-30%) in compost. The most dramatic decreases (>50%) in activity were observed in compost after air-drying. The bacterial LH-PCR community fingerprints were unaffected by frozen storage in all matrices. The effect of storage treatments was tested using a new statistical method based on showing similarity rather than difference of results.

  16. Strategies for soil-based precision agriculture in cotton

    NASA Astrophysics Data System (ADS)

    Neely, Haly L.; Morgan, Cristine L. S.; Stanislav, Scott; Rouze, Gregory; Shi, Yeyin; Thomasson, J. Alex; Valasek, John; Olsenholler, Jeff

    2016-05-01

    The goal of precision agriculture is to increase crop yield while maximizing the use efficiency of farm resources. In this application, UAV-based systems are presenting agricultural researchers with an opportunity to study crop response to environmental and management factors in real-time without disturbing the crop. The spatial variability soil properties, which drive crop yield and quality, cannot be changed and thus keen agronomic choices with soil variability in mind have the potential to increase profits. Additionally, measuring crop stress over time and in response to management and environmental conditions may enable agronomists and plant breeders to make more informed decisions about variety selection than the traditional end-of-season yield and quality measurements. In a previous study, seed-cotton yield was measured over 4 years and compared with soil variability as mapped by a proximal soil sensor. It was found that soil properties had a significant effect on seed-cotton yield and the effect was not consistent across years due to different precipitation conditions. However, when seed-cotton yield was compared to the normalized difference vegetation index (NDVI), as measured using a multispectral camera from a UAV, predictions improved. Further improvement was seen when soil-only pixels were removed from the analysis. On-going studies are using UAV-based data to uncover the thresholds for stress and yield potential. Long-term goals of this research include detecting stress before yield is reduced and selecting better adapted varieties.

  17. Improving the prediction of arsenic contents in agricultural soils by combining the reflectance spectroscopy of soils and rice plants

    NASA Astrophysics Data System (ADS)

    Shi, Tiezhu; Wang, Junjie; Chen, Yiyun; Wu, Guofeng

    2016-10-01

    Visible and near-infrared reflectance spectroscopy provides a beneficial tool for investigating soil heavy metal contamination. This study aimed to investigate mechanisms of soil arsenic prediction using laboratory based soil and leaf spectra, compare the prediction of arsenic content using soil spectra with that using rice plant spectra, and determine whether the combination of both could improve the prediction of soil arsenic content. A total of 100 samples were collected and the reflectance spectra of soils and rice plants were measured using a FieldSpec3 portable spectroradiometer (350-2500 nm). After eliminating spectral outliers, the reflectance spectra were divided into calibration (n = 62) and validation (n = 32) data sets using the Kennard-Stone algorithm. Genetic algorithm (GA) was used to select useful spectral variables for soil arsenic prediction. Thereafter, the GA-selected spectral variables of the soil and leaf spectra were individually and jointly employed to calibrate the partial least squares regression (PLSR) models using the calibration data set. The regression models were validated and compared using independent validation data set. Furthermore, the correlation coefficients of soil arsenic against soil organic matter, leaf arsenic and leaf chlorophyll were calculated, and the important wavelengths for PLSR modeling were extracted. Results showed that arsenic prediction using the leaf spectra (coefficient of determination in validation, Rv2 = 0.54; root mean square error in validation, RMSEv = 12.99 mg kg-1; and residual prediction deviation in validation, RPDv = 1.35) was slightly better than using the soil spectra (Rv2 = 0.42, RMSEv = 13.35 mg kg-1, and RPDv = 1.31). However, results also showed that the combinational use of soil and leaf spectra resulted in higher arsenic prediction (Rv2 = 0.63, RMSEv = 11.94 mg kg-1, RPDv = 1.47) compared with either soil or leaf spectra alone. Soil spectral bands near 480, 600, 670, 810, 1980, 2050 and

  18. Phosphorus leaching from agricultural soils of the delmarva peninsula, USA.

    PubMed

    Kleinman, Peter J A; Church, Clinton; Saporito, Lou S; McGrath, Josh M; Reiter, Mark S; Allen, Arthur L; Tingle, Shawn; Binford, Greg D; Han, Kun; Joern, Brad C

    2015-03-01

    Leaching of phosphorus (P) mobilizes edaphic and applied sources of P and is a primary pathway of concern in agricultural soils of the Delmarva Peninsula, which defines the eastern boundary of the eutrophic Chesapeake Bay. We evaluated P leaching before and after poultry litter application from intact soil columns (30 cm diameter × 50 cm depth) obtained from low- and high-P members of four dominant Delmarva Peninsula soils. Surface soil textures ranged from fine sand to silt loam, and Mehlich-3 soil P ranged from 64 to 628 mg kg. Irrigation of soil columns before litter application pointed to surface soil P controls on dissolved P in leachate (with soil P sorption saturation providing a stronger relationship than Mehlich-3 P); however, strong relationships between P in the subsoil (45-50 cm) and leachate P concentrations were also observed ( = 0.61-0.73). After poultry litter application (4.5 Mg ha), leachate P concentrations and loads increased significantly for the finest-textured soils, consistent with observations that well-structured soils have the greatest propensity to transmit applied P. Phosphorus derived from poultry litter appeared to contribute 41 and 76% of total P loss in leachate from the two soils with the finest textures. Results point to soil P, including P sorption saturation, as a sound metric of P loss potential in leachate when manure is not an acute source of P but highlight the need to factor in macropore transport potential to predict leaching losses from applied P sources. PMID:26023971

  19. Assessing and monitoring soil quality at agricultural waste disposal areas-Soil Indicators

    NASA Astrophysics Data System (ADS)

    Doula, Maria; Kavvadias, Victor; Sarris, Apostolos; Lolos, Polykarpos; Liakopoulou, Nektaria; Hliaoutakis, Aggelos; Kydonakis, Aris

    2014-05-01

    The necessity of elaborating indicators is one of the priorities identified by the United Nations Convention to Combat Desertification (UNCCD). The establishment of an indicator monitoring system for environmental purposes is dependent on the geographical scale. Some indicators such as rain seasonality or drainage density are useful over large areas, but others such as soil depth, vegetation cover type, and land ownership are only applicable locally. In order to practically enhance the sustainability of land management, research on using indicators for assessing land degradation risk must initially focus at local level because management decisions by individual land users are taken at this level. Soils that accept wastes disposal, apart from progressive degradation, may cause serious problems to the surrounding environment (humans, animals, plants, water systems, etc.), and thus, soil quality should be necessarily monitored. Therefore, quality indicators, representative of the specific waste type, should be established and monitored periodically. Since waste composition is dependent on their origin, specific indicators for each waste type should be established. Considering agricultural wastes, such a specification, however, could be difficult, since almost all agricultural wastes are characterized by increased concentrations of the same elements, namely, phosphorous, nitrogen, potassium, sulfur, etc.; contain large amounts of organic matter; and have very high values of chemical oxygen demand (COD), biochemical oxygen demand (BOD), and electrical conductivity. Two LIFE projects, namely AgroStrat and PROSODOL are focused on the identification of soil indicators for the assessment of soil quality at areas where pistachio wastes and olive mill wastes are disposed, respectively. Many soil samples were collected periodically for 2 years during PROSODOL and one year during AgroStrat (this project is in progress) from waste disposal areas and analyzed for 23 parameters

  20. Adsorption and degradation of five selected antibiotics in agricultural soil.

    PubMed

    Pan, Min; Chu, L M

    2016-03-01

    Large quantities of antibiotics are being added to agricultural fields worldwide through the application of wastewater, manures and biosolids, resulting in antibiotic contamination and elevated environmental risks in terrestrial environments. Most studies on the environmental fate of antibiotics focus on aquatic environments or wastewater treatment plants. Little is known about the behavior of antibiotics at environmentally relevant concentrations in agricultural soil. In this study we evaluated the adsorption and degradation of five different antibiotics (tetracycline, sulfamethazine, norfloxacin, erythromycin, and chloramphenicol) in sterilized and non-sterilized agricultural soils under aerobic and anaerobic conditions. Adsorption was highest for tetracycline (Kd, 1093 L/kg), while that for sulfamethazine was negligible (Kd, 1.365 L/kg). All five antibiotics were susceptible to microbial degradation under aerobic conditions, with half-lives ranging from 2.9 to 43.3 d in non-sterilized soil and 40.8 to 86.6 d in sterilized soil. Degradation occurred at a higher rate under aerobic conditions but was relatively persistent under anaerobic conditions. For all the antibiotics, a higher initial concentration was found to slow down degradation and prolong persistence in soil. The degradation behavior of the antibiotics varied in relation to their physicochemical properties as well as the microbial activities and aeration of the recipient soil. The poor adsorption and relative persistence of sulfamethazine under both aerobic and anaerobic conditions suggest that it may pose a higher risk to groundwater quality. An equation was proposed to predict the fate of antibiotics in soil under different field conditions, and assess their risks to the environment.

  1. Adsorption and degradation of five selected antibiotics in agricultural soil.

    PubMed

    Pan, Min; Chu, L M

    2016-03-01

    Large quantities of antibiotics are being added to agricultural fields worldwide through the application of wastewater, manures and biosolids, resulting in antibiotic contamination and elevated environmental risks in terrestrial environments. Most studies on the environmental fate of antibiotics focus on aquatic environments or wastewater treatment plants. Little is known about the behavior of antibiotics at environmentally relevant concentrations in agricultural soil. In this study we evaluated the adsorption and degradation of five different antibiotics (tetracycline, sulfamethazine, norfloxacin, erythromycin, and chloramphenicol) in sterilized and non-sterilized agricultural soils under aerobic and anaerobic conditions. Adsorption was highest for tetracycline (Kd, 1093 L/kg), while that for sulfamethazine was negligible (Kd, 1.365 L/kg). All five antibiotics were susceptible to microbial degradation under aerobic conditions, with half-lives ranging from 2.9 to 43.3 d in non-sterilized soil and 40.8 to 86.6 d in sterilized soil. Degradation occurred at a higher rate under aerobic conditions but was relatively persistent under anaerobic conditions. For all the antibiotics, a higher initial concentration was found to slow down degradation and prolong persistence in soil. The degradation behavior of the antibiotics varied in relation to their physicochemical properties as well as the microbial activities and aeration of the recipient soil. The poor adsorption and relative persistence of sulfamethazine under both aerobic and anaerobic conditions suggest that it may pose a higher risk to groundwater quality. An equation was proposed to predict the fate of antibiotics in soil under different field conditions, and assess their risks to the environment. PMID:26745292

  2. Applying nitrogen site-specifically using soil electrical conductivity maps and precision agriculture technology.

    PubMed

    Lund, E D; Wolcott, M C; Hanson, G P

    2001-10-16

    Soil texture varies significantly within many agricultural fields. The physical properties of soil, such as soil texture, have a direct effect on water holding capacity, cation exchange capacity, crop yield, production capability, and nitrogen (N) loss variations within a field. In short, mobile nutrients are used, lost, and stored differently as soil textures vary. A uniform application of N to varying soils results in a wide range of N availability to the crop. N applied in excess of crop usage results in a waste of the grower"s input expense, a potential negative effect on the environment, and in some crops a reduction of crop quality, yield, and harvestability. Inadequate N levels represent a lost opportunity for crop yield and profit. The global positioning system (GPS)-referenced mapping of bulk soil electrical conductivity (EC) has been shown to serve as an effective proxy for soil texture and other soil properties. Soils with a high clay content conduct more electricity than coarser textured soils, which results in higher EC values. This paper will describe the EC mapping process and provide case studies of site-specific N applications based on EC maps. Results of these case studies suggest that N can be managed site-specifically using a variety of management practices, including soil sampling, variable yield goals, and cropping history.

  3. A simple model of carbon in the soil profile for agricultural soils in Northwestern Europe

    NASA Astrophysics Data System (ADS)

    Taghizadeh-Toosi, Arezoo; Hutchings, Nicholas J.; Vejlin, Jonas; Christensen, Bent T.; Olesen, Jørgen E.

    2014-05-01

    World soil carbon (C) stocks are second to those in the ocean, and represent three times as much C as currently present in the atmosphere. The amount of C in soil may play a significant role in carbon exchanges between the atmosphere and the terrestrial environment. The C-TOOL model is a three-pool linked soil organic carbon (SOC) model in well-drained mineral soils under agricultural land management to allow generalized parameterization for estimating effects of management measures at medium to long time scales for the entire soil profile (0-100 cm). C-TOOL has been developed to enable simulations of SOC turnover in soil using temperature dependent first order kinetics for describing decomposition. Compared with many other SOC models, C-TOOL applies a less complicated structure, which facilitates easier calibration, and it requires only few inputs (i.e., average monthly air temperature, soil clay content,soil carbon-to-nitrogen ratio, and C inputs to the soil from plants and other sources). C-TOOL was parameterized using SOC and radiocarbon data from selected long-term field treatments in United Kingdom, Sweden and Denmark. However, less data were available for evaluation of subsoil C (25-100 cm) from the long-term experiments applied. In Denmark a national 7×7 km grid net was established in 1986 for soil C monitoring down to 100 cm depth. The results of SOC showed a significant decline from 1997 to 2009 in the 0-50 cm soil layer. This was mainly attributed to changes in the 25-50 cm layer, where a decline in SOC was found for all soil texture types. Across the period 1986 to 2009 there was clear tendency for increasing SOC on the sandy soils and reductions on the loamy soils. This effect is linked to land use, since grasslands and dairy farms are more abundant in the western parts of Denmark, where most of the sandy soils are located. The results and the data from soil monitoring have been used to validate the C-TOOL modelling approach used for accounting of

  4. Agriculture intensifies soil moisture decline in Northern China

    NASA Astrophysics Data System (ADS)

    Liu, Yaling; Pan, Zhihua; Zhuang, Qianlai; Miralles, Diego G.; Teuling, Adriaan J.; Zhang, Tonglin; An, Pingli; Dong, Zhiqiang; Zhang, Jingting; He, Di; Wang, Liwei; Pan, Xuebiao; Bai, Wei; Niyogi, Dev

    2015-07-01

    Northern China is one of the most densely populated regions in the world. Agricultural activities have intensified since the 1980s to provide food security to the country. However, this intensification has likely contributed to an increasing scarcity in water resources, which may in turn be endangering food security. Based on in-situ measurements of soil moisture collected in agricultural plots during 1983-2012, we find that topsoil (0-50 cm) volumetric water content during the growing season has declined significantly (p < 0.01), with a trend of -0.011 to -0.015 m3 m-3 per decade. Observed discharge declines for the three large river basins are consistent with the effects of agricultural intensification, although other factors (e.g. dam constructions) likely have contributed to these trends. Practices like fertilizer application have favoured biomass growth and increased transpiration rates, thus reducing available soil water. In addition, the rapid proliferation of water-expensive crops (e.g., maize) and the expansion of the area dedicated to food production have also contributed to soil drying. Adoption of alternative agricultural practices that can meet the immediate food demand without compromising future water resources seem critical for the sustainability of the food production system.

  5. Agriculture intensifies soil moisture decline in Northern China.

    PubMed

    Liu, Yaling; Pan, Zhihua; Zhuang, Qianlai; Miralles, Diego G; Teuling, Adriaan J; Zhang, Tonglin; An, Pingli; Dong, Zhiqiang; Zhang, Jingting; He, Di; Wang, Liwei; Pan, Xuebiao; Bai, Wei; Niyogi, Dev

    2015-01-01

    Northern China is one of the most densely populated regions in the world. Agricultural activities have intensified since the 1980s to provide food security to the country. However, this intensification has likely contributed to an increasing scarcity in water resources, which may in turn be endangering food security. Based on in-situ measurements of soil moisture collected in agricultural plots during 1983-2012, we find that topsoil (0-50 cm) volumetric water content during the growing season has declined significantly (p < 0.01), with a trend of -0.011 to -0.015 m(3) m(-3) per decade. Observed discharge declines for the three large river basins are consistent with the effects of agricultural intensification, although other factors (e.g. dam constructions) likely have contributed to these trends. Practices like fertilizer application have favoured biomass growth and increased transpiration rates, thus reducing available soil water. In addition, the rapid proliferation of water-expensive crops (e.g., maize) and the expansion of the area dedicated to food production have also contributed to soil drying. Adoption of alternative agricultural practices that can meet the immediate food demand without compromising future water resources seem critical for the sustainability of the food production system. PMID:26158774

  6. Agriculture intensifies soil moisture decline in Northern China

    DOE PAGES

    Liu, Yaling; Pan, Zhihua; Zhuang, Qianlai; Miralles, Diego; Teuling, Adriann; Zhang, Tonglin; An, Pingli; Dong, Zhiqiang; Zhang, Jingting; He, Di; et al

    2015-07-09

    Northern China is one of the most densely populated regions in the world. Agricultural activities have intensified since the 1980s to provide food security to the country. However, this intensification has likely contributed to an increasing scarcity in water resources, which may in turn be endangering food security. Based on in-situ measurements of soil moisture collected in agricultural plots during 1983–2012, we find that topsoil (0–50 cm) volumetric water content during the growing season has declined significantly (p<0.01), with a trend of -0.011 to -0.015 m3 m-3 per decade. Observed discharge declines for the three large river basins are consistentmore » with the effects of agricultural intensification, although other factors (e.g. dam constructions) likely have contributed to these trends. Practices like fertilizer application have favoured biomass growth and increased transpiration rates, thus reducing available soil water. In addition, the rapid proliferation of water-expensive crops (e.g., maize) and the expansion of the area dedicated to food production have also contributed to soil drying. Adoption of alternative agricultural practices that can meet the immediate food demand without compromising future water resources seem critical for the sustainability of the food production system.« less

  7. Agriculture intensifies soil moisture decline in Northern China

    SciTech Connect

    Liu, Yaling; Pan, Zhihua; Zhuang, Qianlai; Miralles, Diego; Teuling, Adriann; Zhang, Tonglin; An, Pingli; Dong, Zhiqiang; Zhang, Jingting; He, Di; Wang, Liwei; Pan, Xuebiao; Bai, Wei; Niyogi, Dev

    2015-07-09

    Northern China is one of the most densely populated regions in the world. Agricultural activities have intensified since the 1980s to provide food security to the country. However, this intensification has likely contributed to an increasing scarcity in water resources, which may in turn be endangering food security. Based on in-situ measurements of soil moisture collected in agricultural plots during 1983–2012, we find that topsoil (0–50 cm) volumetric water content during the growing season has declined significantly (p<0.01), with a trend of -0.011 to -0.015 m3 m-3 per decade. Observed discharge declines for the three large river basins are consistent with the effects of agricultural intensification, although other factors (e.g. dam constructions) likely have contributed to these trends. Practices like fertilizer application have favoured biomass growth and increased transpiration rates, thus reducing available soil water. In addition, the rapid proliferation of water-expensive crops (e.g., maize) and the expansion of the area dedicated to food production have also contributed to soil drying. Adoption of alternative agricultural practices that can meet the immediate food demand without compromising future water resources seem critical for the sustainability of the food production system.

  8. Agriculture intensifies soil moisture decline in Northern China.

    PubMed

    Liu, Yaling; Pan, Zhihua; Zhuang, Qianlai; Miralles, Diego G; Teuling, Adriaan J; Zhang, Tonglin; An, Pingli; Dong, Zhiqiang; Zhang, Jingting; He, Di; Wang, Liwei; Pan, Xuebiao; Bai, Wei; Niyogi, Dev

    2015-07-09

    Northern China is one of the most densely populated regions in the world. Agricultural activities have intensified since the 1980s to provide food security to the country. However, this intensification has likely contributed to an increasing scarcity in water resources, which may in turn be endangering food security. Based on in-situ measurements of soil moisture collected in agricultural plots during 1983-2012, we find that topsoil (0-50 cm) volumetric water content during the growing season has declined significantly (p < 0.01), with a trend of -0.011 to -0.015 m(3) m(-3) per decade. Observed discharge declines for the three large river basins are consistent with the effects of agricultural intensification, although other factors (e.g. dam constructions) likely have contributed to these trends. Practices like fertilizer application have favoured biomass growth and increased transpiration rates, thus reducing available soil water. In addition, the rapid proliferation of water-expensive crops (e.g., maize) and the expansion of the area dedicated to food production have also contributed to soil drying. Adoption of alternative agricultural practices that can meet the immediate food demand without compromising future water resources seem critical for the sustainability of the food production system.

  9. Agriculture intensifies soil moisture decline in Northern China

    PubMed Central

    Liu, Yaling; Pan, Zhihua; Zhuang, Qianlai; Miralles, Diego G.; Teuling, Adriaan J.; Zhang, Tonglin; An, Pingli; Dong, Zhiqiang; Zhang, Jingting; He, Di; Wang, Liwei; Pan, Xuebiao; Bai, Wei; Niyogi, Dev

    2015-01-01

    Northern China is one of the most densely populated regions in the world. Agricultural activities have intensified since the 1980s to provide food security to the country. However, this intensification has likely contributed to an increasing scarcity in water resources, which may in turn be endangering food security. Based on in-situ measurements of soil moisture collected in agricultural plots during 1983–2012, we find that topsoil (0–50 cm) volumetric water content during the growing season has declined significantly (p < 0.01), with a trend of −0.011 to −0.015 m3 m−3 per decade. Observed discharge declines for the three large river basins are consistent with the effects of agricultural intensification, although other factors (e.g. dam constructions) likely have contributed to these trends. Practices like fertilizer application have favoured biomass growth and increased transpiration rates, thus reducing available soil water. In addition, the rapid proliferation of water-expensive crops (e.g., maize) and the expansion of the area dedicated to food production have also contributed to soil drying. Adoption of alternative agricultural practices that can meet the immediate food demand without compromising future water resources seem critical for the sustainability of the food production system. PMID:26158774

  10. Distribution and speciation of metals (Cu, Zn, Cd, and Pb) in agricultural and non-agricultural soils near a stream upriver from the Pearl River, China.

    PubMed

    Yang, Silin; Zhou, Dequn; Yu, Huayong; Wei, Rong; Pan, Bo

    2013-06-01

    The distribution and chemical speciation of typical metals (Cu, Zn, Cd and Pb) in agricultural and non-agricultural soils were investigated in the area of Nanpan River, upstream of the Pearl River. The investigated four metals showed higher concentrations in agricultural soils than in non-agricultural soils, and the site located in factory district contained metals much higher than the other sampling sites. These observations suggested that human activities, such as water irrigation, fertilizer and pesticide applications might have a major impact on the distribution of metals. Metal speciation analysis presented that Cu, Zn and Cd were dominated by the residual fraction, while Pb was dominated by the reducible fraction. Because of the low mobility of the metals in the investigated area, no remarkable difference could be observed between upstream and downstream separated by the factory site. PMID:23466733

  11. Distribution and speciation of metals (Cu, Zn, Cd, and Pb) in agricultural and non-agricultural soils near a stream upriver from the Pearl River, China.

    PubMed

    Yang, Silin; Zhou, Dequn; Yu, Huayong; Wei, Rong; Pan, Bo

    2013-06-01

    The distribution and chemical speciation of typical metals (Cu, Zn, Cd and Pb) in agricultural and non-agricultural soils were investigated in the area of Nanpan River, upstream of the Pearl River. The investigated four metals showed higher concentrations in agricultural soils than in non-agricultural soils, and the site located in factory district contained metals much higher than the other sampling sites. These observations suggested that human activities, such as water irrigation, fertilizer and pesticide applications might have a major impact on the distribution of metals. Metal speciation analysis presented that Cu, Zn and Cd were dominated by the residual fraction, while Pb was dominated by the reducible fraction. Because of the low mobility of the metals in the investigated area, no remarkable difference could be observed between upstream and downstream separated by the factory site.

  12. Relating results from earthworm toxicity tests to agricultural soil

    USGS Publications Warehouse

    Beyer, W.N.; Greig-Smith, P.W.

    1992-01-01

    The artificial soil tests of the European Economic Community and of the Organization for Economic Cooperation produce data relating earthworm mortality to pesticide concentrations in soil under laboratory conditions. To apply these results to agricultural soils it is necessary to relate these concentrations to amounts of pesticide applied per area. This paper reviews the relevant published literature and suggests a simple relation for regulatory use. Hazards to earthworms from pesticides are suggested to be greatest soon after application, when the pesticides may be concentrated in a soil layer a few millimeters thick. For estimating exposure of earthworms, however, a thicker soil layer should be considered, to account for their movement through soil. During favorable weather conditions, earthworms belonging to species appropriate to the artificial soil test have been reported to confine their activity to a layer about 5 cm. If a 5-cm layer is accepted as relevant for regulatory purposes, then an application of 1 kg/ha would be equivalent to 1-67 ppm (dry) in the artificial soil test.

  13. Measurement of the open porosity of agricultural soils with acoustic waves

    NASA Astrophysics Data System (ADS)

    Luong, Jeanne; Mercatoris, Benoit; Destain, Marie-France

    2015-04-01

    The space between agricultural soil aggregates is defined as structural porosity. It plays important roles in soil key functions that an agricultural soil performs in the global ecosystem. Porosity is one of the soil properties that affect plant growth along with soil texture, aggregate size, aeration and water holding capacity (Alaoui et al. 2011). Water supplies regulation of agricultural soil is related to the number of very small pores present in a soil due to the effect of capillarity. Change of porosity also affect the evaporation of the water on the surface (Le Maitre et al. 2014). Furthermore, soil is a habitat for soils organisms, and most living organisms, including plant roots and microorganisms require oxygen. These organisms breathe easier in a less compacted soil with a wide range of pores sizes. Soil compaction by agricultural engine degrades soil porosity. At the same time, fragmentation with tillage tools, creation of cracks due to wetting/drying and freezing/thawing cycles and effects of soil fauna can regenerate soil porosity. Soil compaction increases bulk density since soil grains are rearranged decreasing void space and bringing them into closer contact (Hamza & Anderson 2005). Drainage is reduced, erosion is facilitated and crop production decreases in a compacted soil. Determining soil porosity, giving insight on the soil compaction, with the aim to provide advices to farmers in their soil optimization towards crop production, is thus an important challenge. Acoustic wave velocity has been correlated to the porosity and the acoustic attenuation to the water content (Oelze et al. 2002). Recent studies have shown some correlations between the velocity of acoustic waves, the porosity and the stress state of soil samples (Lu et al. 2004; Lu 2005; Lu & Sabatier 2009), concluding that the ultrasonic waves are a promising tool for the rapid characterisation of unsaturated porous soils. Propagation wave velocity tends to decrease in a high porous

  14. Remote sensing techniques for soil moisture and agricultural drought monitoring

    NASA Astrophysics Data System (ADS)

    Wang, Lingli

    Drought is the most complex and least understood of all natural hazards, affecting more people than any other hazard. Soil moisture is a primary indicator for agricultural drought. This dissertation is aimed at evaluating and investigating soil moisture and drought monitoring using remote sensing techniques. Recent technological advances in remote sensing have shown that soil moisture can be measured by a variety of remote sensing techniques, each with its own strengths and weaknesses. This research is designed to combine the strengths of optical/infrared as well as microwave remote sensing approaches for soil moisture estimation. A soil moisture estimation algorithm at moderate resolution was developed based on the well known 'Universal Triangle' relation by using MODIS land parameters as well as ground measured soil moisture. Though lower in spatial resolution, AMSR-E microwave measurements provides daily global soil moisture of the top soil layer, which are typically less affected by clouds, making them complementary to MODIS measurements over regions of clouds. Considering that the 'Universal Triangle' approach for soil moisture estimation is based on empirical relations which lack solid physical basis, a new physics based drought index, the Normalized Multi-band Drought Index (NMDI) was proposed for monitoring soil and vegetation moisture from space by using one near-infrared (NIR) and two shortwave infrared (SWIR) channels. Typical soil reflectance spectra and satellite acquired canopy reflectances are used to validate the usefulness of NMDI. Its ability for active fire detection has also been investigated using forest fires burning in southern Georgia, USA and southern Greece in 2007. Combining information from multiple NIR and SWIR channels makes NMDI a most promising indicator for drought monitoring and active fire detecting. Given the current technology, satellite remote sensing can only provide soil moisture measurements for the top soil profile, and

  15. Polyoxyethylene Tallow Amine, a Glyphosate Formulation Adjuvant: Soil Adsorption Characteristics, Degradation Profile, and Occurrence on Selected Soils from Agricultural Fields in Iowa, Illinois, Indiana, Kansas, Mississippi, and Missouri.

    PubMed

    Tush, Daniel; Meyer, Michael T

    2016-06-01

    Polyoxyethylene tallow amine (POEA) is an inert ingredient added to formulations of glyphosate, the most widely applied agricultural herbicide. POEA has been shown to have toxic effects to some aquatic organisms making the potential transport of POEA from the application site into the environment an important concern. This study characterized the adsorption of POEA to soils and assessed its occurrence and homologue distribution in agricultural soils from six states. Adsorption experiments of POEA to selected soils showed that POEA adsorbed much stronger than glyphosate; calcium chloride increased the binding of POEA; and the binding of POEA was stronger in low pH conditions. POEA was detected on a soil sample from an agricultural field near Lawrence, Kansas, but with a loss of homologues that contain alkenes. POEA was also detected on soil samples collected between February and early March from corn and soybean fields from ten different sites in five other states (Iowa, Illinois, Indiana, Missouri, Mississippi). This is the first study to characterize the adsorption of POEA to soil, the potential widespread occurrence of POEA on agricultural soils, and the persistence of the POEA homologues on agricultural soils into the following growing season. PMID:27163278

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

    NASA Astrophysics Data System (ADS)

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

    2013-03-01

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

  17. Aerosol emissions from biochar-amended agricultural soils

    NASA Astrophysics Data System (ADS)

    Ravi, S.; Sharratt, B. S.; Li, J. J.; Olshvevski, S.; Meng, Z.; Zhang, J.

    2015-12-01

    Agricultural production is a major contributor to anthropogenic greenhouse gas emissions and associated global warming. In this regard, novel carbon sequestration strategies such as large-scale biochar application may provide sustainable pathways to increase the terrestrial storage of carbon in agricultural areas. Biochar has a long residence time in the soil and hence understanding the soil properties affected by biochar addition needs to be investigated to identify the tradeoffs and synergies of large-scale biochar application. Even though several studies have investigated the impacts of biochar application on a variety of soil properties, very few studies have investigated the impacts on soil erosion, in particular wind (aeolian) erosion and subsequent particulate emissions. Using a combination of wind tunnel studies and laboratory experiments, we investigated the dust emission potential of biochar-amended agricultural soils. We amended biochar (unsieved or sieved to appropriate particle size; application rates ranging from 1 - 5 % of the soil by weight) to three soil types (sand, sandy loam, and silt loam) and estimated the changes in threshold shear velocity for wind erosion and dust emission potential in comparison to control soils. Our experiments demonstrate that emissions of fine biochar particles may result from two mechanisms (a) very fine biochar particles (suspension size) that are entrained into the air stream when the wind velocity exceeds the threshold, and (b) production of fine biochar particles originating from the abrasion by quartz grains. The results indicate that biochar application significantly increased particulate emissions and more interestingly, the rate of increase was found to be higher in the intermediate range of biochar application. As fine biochar particles effectively adsorb/trap contaminants and pathogens from the soil, the preferential erosion of fine biochar particles by wind may lead to concentration of contaminants in the

  18. Fertilizer impact on biogenic nitric oxide emissions from agricultural soils of the Taklimakan desert (Xinjiang, China)

    NASA Astrophysics Data System (ADS)

    Fechner, A. D.; Behrendt, T.; Bruse, M.; Mamtimin, B.; Andreae, M. O.; Meixner, F. X.

    2012-04-01

    It is known that soil microbial processes play a crucial role in the production and consumption of atmospheric trace gases worldwide. Soils are mostly a major source of biogenic nitric oxide (NO). The main influencing factors controlling soil NO emissions are soil moisture, soil temperature, as well as nutrient availability. Adding fertilizer to agricultural soils changes the pool of nutrients and impacts the net NO emission from these soils. Irrigated and fertilized oases around the great Central Asian Taklamakan desert form the backbone of the agricultural output (80% of the Chinese cotton production) of the Xinjiang Uygur Autonomous Region (NW-China). While nowadays 90% of the agricultural output is produced on just 4.3% of Xinjiang's total area, recent and future enlargement of farmland and intensification of agriculture will definitely impact the regional soil NO emission and consequently the budget of nitrogen oxides and ozone. We present a systematic laboratory study of the influence of urea (CH4N2O) and diammonium hydrogen phosphate ((NH4)2HPO4, DAP) fertilizer on NO emissions from Xinjiang soil samples. Urea is the most widely and excessively applied fertilizer in Xinjiang. Typically, about 600 kg ha-1 yr-1(in terms of mass of nitrogen) were applied to a cotton field in four separate events. In the laboratory, the fertilizer was applied accordingly, ranging from one quarter of the field amount within one of the four events (i.e. 37.5 kg ha-1 yr-1) to quadruple of that (150 kg ha-1 yr-1). Two different measurement series have been performed on six sub- samples (each out of a total of three soil samples taken in Xinjiang): the first series was conducted solely with urea fertilizer, the second one with a mixture of urea and DAP (2:1). All sub-samples were prepared in a standardized way: a fixed mass of soil (~0.06 kg, dried in field) was sieved (2 mm) and stored at 4° C. Then it was wetted up to a soil moisture tension of 1.8 pF. Subsequently, fertilizer was

  19. Arsenic and lead (beudantite) contamination of agricultural rice soils in the Guandu Plain of northern Taiwan.

    PubMed

    Chiang, Kai Ying; Lin, Kuo Chuan; Lin, Sheng Chi; Chang, Tsun-Kuo; Wang, Ming Kuang

    2010-09-15

    This study investigates the species of As and Pb (beudantite) residues present in the seriously contaminated agricultural rice soils of the Guandu Plain. Two pedons in the Guandu Plain agricultural soils, each pedon separated into five horizons (each of 20 cm) were collected for this study. Soil samples were packed into a column for leaching with simulated acid rains. Soil pH ranged from 5.1 to 7.1 with high base saturation. Soils can be classified as clay loam, mixed, thermic, Typic or Umbric Albaqualfs. The XRD analysis indicated the beudantite particles are present in clay fractions, showing high concentrations of As and Pb. This is because of 50-100 years ago irrigation water was introduced from Huang Gang Creek of hot springs containing high concentrations of As and Pb. Only low concentrations of As and Pb can be leached out with simulated acid rains (i.e., pHs 2 and 4), even through 40 pore volumes of leaching experiments. The sequential extraction experiments resulted in the high portions of As and Pb remaining in the amorphous, Fe and Al oxyhydroxides and residual fractions. Thus, the remediation of As and Pb in this agricultural rice paddy soils merits further study. PMID:20566242

  20. Distribution of arsenic and trace metals in the floodplain agricultural soil of Bangladesh.

    PubMed

    Ahsan, Dewan Ali; DelValls, Tomas Angel; Blasco, Julian

    2009-01-01

    Arsenic contaminated groundwater of Bangladesh is one of the largest natural calamities of the world. Soil samples were collected from floodplain agricultural land of Faridpur and Dhamrai regions to estimate the concentration of arsenic and other trace metals (copper, nickel, zinc, chromium, cadmium, lead, selenium, cobalt, mercury, and manganese). Average arsenic in Faridpur soil was recorded more than three times higher than the world limit and nearly five times higher than that of Dhamrai. The average copper, chromium and cobalt both in Faridpur and Dhamrai agricultural soil were also higher than the Dutch and the world standards. Both Fardipur and Dhamrai soil contain low amount of selenium in comparison to world limit (0.7 mg kg(-1)). A poor correlation between manganese and arsenic was noticed in Faridpur. This may be played a subordinate role in the fixation of arsenic in soil. This study also reveals that the area which has arsenic and trace metal contaminated groundwater may also contain high level of arsenic and trace metals in the agricultural soil due to irrigation with contaminated groundwater.

  1. Mineralization of soil organic matter in biochar amended agricultural landscape

    NASA Astrophysics Data System (ADS)

    Chintala, R.; Clay, D. E.; Schumacher, T. E.; Kumar, S.; Malo, D. D.

    2015-12-01

    Pyrogenic biochar materials have been identified as a promising soil amendment to enhance climate resilience, increase soil carbon recalcitrance and achieve sustainable crop production. A three year field study was initiated in 2013 to study the impact of biochar on soil carbon and nitrogen storage on an eroded Maddock soil series - Sandy, Mixed, Frigid Entic Hapludolls) and deposition Brookings clay loam (Fine-Silty, Mixed, Superactive, Frigid Pachic Hapludolls) landscape positions. Three biochars produced from corn stover (Zea mays L.), Ponderosa pine (Pinus ponderosa Lawson and C. Lawson) wood residue, and switchgrass (Panicum virgatum L.) were incorporated at 9.75 Mg ha-1 rate (≈7.5 cm soil depth and 1.3 g/cm3 soil bulk density) with a rototiller. The changes in chemical fractionation of soil carbon (soluble C, acid hydrolyzable C, total C, and δ13 C) and nitrogen (soluble N, acid hydrolyzable N, total N, and δ14 N) were monitored for two soil depths (0-7.5 and 7.5 - 15 cm). Soluble and acid hydrolyzable fractions of soil C and N were influenced by soil series and were not significantly affected by incorporation of biochars. Based on soil and plant samples to be collected in the fall of 2015, C and N budgets are being developed using isotopic and non-isotopic techniques. Laboratory studies showed that the mean residence time for biochars used in this study ranged from 400 to 666 years. Laboratory and field studies will be compared in the presentation.

  2. Greenhouse gas fluxes from agricultural soils of Kenya and Tanzania

    NASA Astrophysics Data System (ADS)

    Rosenstock, Todd S.; Mpanda, Mathew; Pelster, David E.; Butterbach-Bahl, Klaus; Rufino, Mariana C.; Thiong'o, Margaret; Mutuo, Paul; Abwanda, Sheila; Rioux, Janie; Kimaro, Anthony A.; Neufeldt, Henry

    2016-06-01

    Knowledge of greenhouse gas (GHG) fluxes in soils is a prerequisite to constrain national, continental, and global GHG budgets. However, data characterizing fluxes from agricultural soils of Africa are markedly limited. We measured carbon dioxide (CO2), nitrous oxide (N2O), and methane (CH4) fluxes at 10 farmer-managed sites of six crop types for 1 year in Kenya and Tanzania using static chambers and gas chromatography. Cumulative emissions ranged between 3.5-15.9 Mg CO2-C ha-1 yr-1, 0.4-3.9 kg N2O-N ha-1 yr-1, and -1.2-10.1 kg CH4-C ha-1 yr-1, depending on crop type, environmental conditions, and management. Manure inputs increased CO2 (p = 0.03), but not N2O or CH4, emissions. Soil cultivation had no discernable effect on emissions of any of the three gases. Fluxes of CO2 and N2O were 54-208% greater (p < 0.05) during the wet versus the dry seasons for some, but not all, crop types. The heterogeneity and seasonality of fluxes suggest that the available data describing soil fluxes in Africa, based on measurements of limited duration of only a few crop types and agroecological zones, are inadequate to use as a basis for estimating the impact of agricultural soils on GHG budgets. A targeted effort to understand the magnitude and mechanisms underlying African agricultural soil fluxes is necessary to accurately estimate the influence of this source on the global climate system and for determining mitigation strategies.

  3. Black carbon contribution to stabilised SOM in soil under slash and burn agriculture

    NASA Astrophysics Data System (ADS)

    Rumpel, C.; Chaplot, V.; Valentin, C.

    2008-12-01

    Black carbon (BC) produced during slash and burn agriculture on tropical soils may enhance the soils organic matter content and hence their biological properties. However, once deposited on the soil surface, BC may be subject to erosion and/or microbial decomposition and thus not be preserved on site. Up to now, few studies have been carried out to assess the contribution of BC to the soils stable carbon pool on sites under slash and burn agriculture. The aim of the study was to assess the survival potential of BC in sloping tropical soils of clayey texture. The study was carried out in Northern Laos, where the soils are subjected to addition of black carbon produced by burning of agricultural crop residues. Our conceptual approach included the characterisation of (a) morphologically distinct BC forms and (b) chemical soil fractions. The samples were analysed for elemental content, chemical composition by 13C CPMAS NMR spectroscopy, carbon resistant to acid hydrolysis with HCl, carbon resistant to oxidation with acid dichromate solution and 14C activity. Our results indicated that BC produced by slash and burn agriculture was highly aromatic in nature. Its elemental composition as well as its susceptibility to be lost by chemical oxidation was dependent on its morphology. Acid hydrolysis did not lead to carbon loss from any BC form. We thus hypothesised that BC should be present in the hydrolysis resistant fraction isolated from soil. The charactersation of the chemical composition by 13C CPMAS NMR spectroscopy showed that the hydrolysis residue was composed of highly aromatic carbon. Considering the low lignin content of these soils and the good recovery of bulk soil aromatic carbon signal (80-100%) in the hydrolysis residue, we consider that this fraction may be suitable to assess BC contribution to clayey soils. We suggest that BC isolated as hydrolysis resistant C may represent up to 25% of the soils C as compared to 8% as isolated by acid dichromate oxidation

  4. Measurement of the open porosity of agricultural soils with acoustic waves

    NASA Astrophysics Data System (ADS)

    Luong, Jeanne; Mercatoris, Benoit; Destain, Marie-France

    2015-04-01

    The space between agricultural soil aggregates is defined as structural porosity. It plays important roles in soil key functions that an agricultural soil performs in the global ecosystem. Porosity is one of the soil properties that affect plant growth along with soil texture, aggregate size, aeration and water holding capacity (Alaoui et al. 2011). Water supplies regulation of agricultural soil is related to the number of very small pores present in a soil due to the effect of capillarity. Change of porosity also affect the evaporation of the water on the surface (Le Maitre et al. 2014). Furthermore, soil is a habitat for soils organisms, and most living organisms, including plant roots and microorganisms require oxygen. These organisms breathe easier in a less compacted soil with a wide range of pores sizes. Soil compaction by agricultural engine degrades soil porosity. At the same time, fragmentation with tillage tools, creation of cracks due to wetting/drying and freezing/thawing cycles and effects of soil fauna can regenerate soil porosity. Soil compaction increases bulk density since soil grains are rearranged decreasing void space and bringing them into closer contact (Hamza & Anderson 2005). Drainage is reduced, erosion is facilitated and crop production decreases in a compacted soil. Determining soil porosity, giving insight on the soil compaction, with the aim to provide advices to farmers in their soil optimization towards crop production, is thus an important challenge. Acoustic wave velocity has been correlated to the porosity and the acoustic attenuation to the water content (Oelze et al. 2002). Recent studies have shown some correlations between the velocity of acoustic waves, the porosity and the stress state of soil samples (Lu et al. 2004; Lu 2005; Lu & Sabatier 2009), concluding that the ultrasonic waves are a promising tool for the rapid characterisation of unsaturated porous soils. Propagation wave velocity tends to decrease in a high porous

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

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

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

  6. Distribution of selenium in soils of agricultural fields, western San Joaquin Valley, California

    USGS Publications Warehouse

    Fujii, Roger; Deverel, S.J.; Hatfield, D.B.

    1988-01-01

    Soils from three agricultural fields in the Panoche Creek alluvial fan area in the western San Joaquin Valley, California, were analyzed for soluble, adsorbed, and total concentrations of selenium (Se) to assess the distribution and forms of Se in relation to the leaching of Se from soils. This assessment is needed to evaluate the importance of soil Se in affecting ground water concentrations. Soil samples were collected from three fields with drainage systems of different ages (6, 15, 1.5 yr) and different Se concentrations in drain water (58, 430, 3700 µg L−1, respectively). Concentrations of soluble Se and salinity were highest in soils from the field drained for 1.5 yr and lowest in the field drained for 6 yr. Of the total concentration of soil Se from all three fields, the proportion of adsorbed and soluble Se ranged from 1 to 11% and 2 > 0.68) in saturation extracts of soils sampled from below the water table. In contrast, most soluble salts and Se apparently have been leached from the unsaturated soils in the fields drained for 6 and 15 yr. For the leached soils, dissolution and precipitation of evaporite minerals containing Se may no longer control concentrations of soluble Se.

  7. Fate of the antifungal drug clotrimazole in agricultural soil.

    PubMed

    Sabourin, Lyne; Al-Rajab, Abdul Jabbar; Chapman, Ralph; Lapen, David R; Topp, Edward

    2011-03-01

    Clotrimazole is a broad-spectrum antimycotic drug used for the treatment of dermatological and gynecological infections; it is incompletely broken down during sewage treatment and could potentially reach agricultural land through the application of municipal biosolids or wastewater. In the absence of any environmental fate data, we evaluated the persistence and dissipation pathways of (3)H-clotrimazole during laboratory incubations of agricultural soils. Clotrimazole was removed from a loam (time to dissipate 50% = 68 d), a sandy loam (time to dissipate 50% = 36 d), and a clay loam (time to dissipate 50% = 55 d), with formation of nonextractable residues being the major sink for (3) H. Their parent compound had no significant mineralization, as evidenced by the lack of formation of (3) H(2) O. Up to 15% of the applied radioactivity was recovered in the form of [(3)H]-(2-chlorophenyl)diphenyl methanol. The rate of clotrimazole dissipation in the loam soil did not vary with moisture content, but it was slower at a lower temperature (number of days to dissipate 50% = 275.6 d at 4°C). Addition of municipal biosolids to the loam soil did not vary the clotrimazole dissipation rate. In summary, the present study has established that clotrimazole is dissipated in soil, at rates that varied with soil texture and temperature. Clotrimazole dissipation was accompanied by the formation of nonextractable residues and detectable extractable residues of the transformation product (2-chlorophenyl)diphenyl methanol. PMID:21298703

  8. Antimony mobility in Japanese agricultural soils and the factors affecting antimony sorption behavior.

    PubMed

    Nakamaru, Yasuo; Tagami, Keiko; Uchida, Shigeo

    2006-05-01

    The mobility of antimony (Sb) in Japanese agricultural soils was studied by radiotracer experiments using 124Sb tracer. The soil-solution distribution coefficients (Kd) of Sb were measured for 110 soil samples. These Kds ranged from 1 to 2065 L kg(-1); the geometric mean was 62 L kg(-1) excluding one extremely high value, 2065 L kg(-1). Experimental measurement of Kd showed a decrease with both increasing pH and increasing phosphate concentration. The latter suggested that one aspect of the Sb sorption phenomena in Japanese soil was influenced by specific adsorption of anions such as phosphate. However, other aspects could not be explained by this specific adsorption mechanism, because only 20-40% of soil-sorbed Sb could be extracted by phosphate solution.

  9. Agricultural use of soil, consequences in soil organic matter and hydraulic conductivity compared with natural vegetation in central Spain

    NASA Astrophysics Data System (ADS)

    Vega, Verónica; Carral, Pilar; Alvarez, Ana Maria; Marques, Maria Jose

    2014-05-01

    When ecosystems are under pressure due to high temperatures and water scarcity, the use of land for agriculture can be a handicap for soil and water conservation. The interactions between plants and soils are site-specific. This study provides information about the influence of the preence vs. The absence of vegetation on soil in a semi-arid area of the sout-east of Madrid (Spain, in the Tagus River basin. In this area soil materials are developed over a calcareous-evaporitic lithology. Soils can be classified as Calcisols, having horizons of accumulation with powdered limestone and irregular nodules of calcium carbonate. They can be defined as Haplic Cambisols and Leptic Calcisols (WRB 2006-FAO). The area is mainly used for rainfed agriculture, olive groves, vineyards and cereals. There are some patches of bushes (Quercus sp.) and grasses (Stipa tenacissima L.) although only found on the top of the hills. This study analyses the differences found in soils having three different covers: Quercus coccifera, Stipa tenacissima and lack of vegetation. This last condition was found in the areas between cultivated olive trees. Soil organic matter, porosity and hydraulic conductivity are key properties of soil to understand its ability to adapt to climate or land use changes. In order to measure the influence of different soil covers, four replicates of soil were sampled in each condition at two soil depth, (0-10 cm and 10-20 cm). Hydraulic conductivity was measured in each soil condition and replicate using a Mini-disk® infiltrometer. There were no differences between the two depths sampled. Similarly, there were no changes in electric conductivity (average 0.1±0.03 dS m-1); pH (8.7±0.2) or calcium carbonate content (43±20 %). Nevertheless, significant differences (p>0.001) were found in soil organic matter. The maximum was found in soils under Quercus (4.7±0.5 %), followed by Stipa (2.2±1.1 %). The soil without vegetation in the areas between olive trees had only 0

  10. Sonochemical Digestion of Soil and Sediment Samples

    SciTech Connect

    Sinkov, Sergei I.; Lumetta, Gregg J.

    2006-10-12

    This work was performed as part of a broader effort to automate analytical methods for determination of plutonium and other radioisotopes in environmental samples. The work described here represented a screening study to determine the potential for applying ultrasonic irradiation to sample digestion. Two standard reference materials (SRMs) were used in this study: Columbia River Sediment and Rocky Flats Soil. The key experiments performed are listed below along with a summary of the results. The action of nitric acid, regardless of its concentration and liquid-to-solid ratio, did not achieve dissolution efficiency better that 20%. The major fraction of natural organic matter (NOM) remained undissolved by this treatment. Sonication did not result in improved dissolution for the SRMs tested. The action of hydrofluoric acid at concentrations of 8 M and higher achieved much more pronounced dissolution (up to 97% dissolved for the Rocky Flats soil sample and up to 78% dissolved for the Columbia River Sediment sample). Dissolution efficiency remains constant for solid-to-liquid ratios of up to 0.05 to 1 and decreases for the higher loadings of the solid phase. Sonication produced no measurable effect in improving the dissolution of the samples compared with the control digestion experiments. Combined treatment of the SRM by mixtures of HNO3 and HF showed inferior performance compared with the HF alone. An adverse effect of sonication was found for the Rocky Flats soil material, which became more noticeable at higher HF concentrations. Sonication of the Columbia River sediment samples had no positive effect in the mixed acid treatment. The results indicate that applying ultrasound in an isolated cup horn configuration does not offer any advantage over conventional ''heat and mix'' treatment for dissolution of the soil and sediment based on the SRM examined here. This conclusion, however, is based on an approach that uses gravimetric analysis to determine gross dissolution

  11. Knowledge needs, available practices, and future challenges in agricultural soils

    NASA Astrophysics Data System (ADS)

    Key, Georgina; Whitfield, Mike G.; Cooper, Julia; De Vries, Franciska T.; Collison, Martin; Dedousis, Thanasis; Heathcote, Richard; Roth, Brendan; Mohammed, Shamal; Molyneux, Andrew; Van der Putten, Wim H.; Dicks, Lynn V.; Sutherland, William J.; Bardgett, Richard D.

    2016-10-01

    The goal of this study is to clarify research needs and identify effective practices for enhancing soil health. This was done by a synopsis of soil literature that specifically tests practices designed to maintain or enhance elements of soil health. Using an expert panel of soil scientists and practitioners, we then assessed the evidence in the soil synopsis to highlight practices beneficial to soil health, practices considered detrimental, and practices that need further investigation. A partial Spearman's correlation was used to analyse the panel's responses. We found that increased certainty in scientific evidence led to practices being considered to be more effective due to them being empirically justified. This suggests that for practices to be considered effective and put into practice, a substantial body of research is needed to support the effectiveness of the practice. This is further supported by the high proportion of practices (33 %), such as changing the timing of ploughing or amending the soil with crops grown as green manures, that experts felt had unknown effectiveness, usually due to insufficiently robust evidence. Only 7 of the 27 reviewed practices were considered to be beneficial, or likely to be beneficial in enhancing soil health. These included the use of (1) integrated nutrient management (organic and inorganic amendments); (2) cover crops; (3) crop rotations; (4) intercropping between crop rows or underneath the main crop; (5) formulated chemical compounds (such as nitrification inhibitors); (6) control of traffic and traffic timing; and (7) reducing grazing intensity. Our assessment, which uses the Delphi technique, is increasingly used to improve decision-making in conservation and agricultural policy, identified practices that can be put into practice to benefit soil health. Moreover, it has enabled us to identify practices that need further research and a need for increased communication between researchers, policy-makers, and

  12. Antimicrobial resistance among Pseudomonas spp. and the Bacillus cereus group isolated from Danish agricultural soil.

    PubMed

    Jensen, L B; Baloda, S; Boye, M; Aarestrup, F M

    2001-06-01

    From four Danish pig farms, bacteria of Pseudomonas spp. and the Bacillus cereus group were isolated from soil and susceptibility towards selected antimicrobials was tested. From each farm, soil samples representing soil just before and after spread of animal waste and undisturbed agricultural soil, when possible, were collected. Soil from a well-characterized Danish farm soil (Højbakkegaard) was collected for comparison. The Pseudomonas spp. and B. cereus were chosen as representative for Gram-negative and Gram-positive indigenous soil bacteria to test the effect of spread of animal waste on selection of resistance among soil bacteria. No variations in resistance levels were observed between farms; but when the four differently treated soils were compared, resistance was seen for carbadox, chloramphenicol, nalidixan (nalidixic acid), nitrofurantoin, streptomycin and tetracycline for Pseudomonas spp., and for bacitracin, erythromycin, penicillin and streptomycin for the B. cereus group. Variations in resistance levels were observed when soil before and after spread of animal waste was compared, indicating an effect from spread of animal waste. PMID:11485227

  13. Comparison of soil bacterial communities under diverse agricultural land management and crop production practices.

    PubMed

    Wu, Tiehang; Chellemi, Dan O; Graham, Jim H; Martin, Kendall J; Rosskopf, Erin N

    2008-02-01

    The composition and structure of bacterial communities were examined in soil subjected to a range of diverse agricultural land management and crop production practices. Length heterogeneity polymerase chain reaction (LH-PCR) of bacterial DNA extracted from soil was used to generate amplicon profiles that were analyzed with univariate and multivariate statistical methods. Five land management programs were initiated in July 2000: conventional, organic, continuous removal of vegetation (disk fallow), undisturbed (weed fallow), and bahiagrass pasture (Paspalum notatum var Argentine). Similar levels in the diversity of bacterial 16S rDNA amplicons were detected in soil samples collected from organically and conventionally managed plots 3 and 4 years after initiation of land management programs, whereas significantly lower levels of diversity were observed in samples collected from bahiagrass pasture. Differences in diversity were attributed to effects on how the relative abundance of individual amplicons were distributed (evenness) and not on the total numbers of bacterial 16S rDNA amplicons detected (richness). Similar levels of diversity were detected among all land management programs in soil samples collected after successive years of tomato (Lycopersicon esculentum) cultivation. A different trend was observed after a multivariate examination of the similarities in genetic composition among soil bacterial communities. After 3 years of land management, similarities in genetic composition of soil bacterial communities were observed in plots where disturbance was minimized (bahiagrass and weed fallow). The genetic compositions in plots managed organically were similar to each other and distinct from bacterial communities in other land management programs. After successive years of tomato cultivation and damage from two major hurricanes, only the composition of soil bacterial communities within organically managed plots continued to maintain a high degree of similarity

  14. Heavy metals in agricultural soils of the Pearl River Delta, South China.

    PubMed

    Wong, S C; Li, X D; Zhang, G; Qi, S H; Min, Y S

    2002-01-01

    There is a growing public concern over the potential accumulation of heavy metals in agricultural soils in China owing to rapid urban and industrial development and increasing reliance on agrochemicals in the last several decades. Excessive accumulation of heavy metals in agricultural soils may not only result in environmental contamination, but elevated heavy metal uptake by crops may also affect food quality and safety. The present study is aimed at studying heavy metal concentrations of crop, paddy and natural soils in the Pearl River Delta, one of the most developed regions in China. In addition, some selected soil samples were analyzed for chemical partitioning of Co, Cu, Pb and Zn. The Pb isotopic composition of the extracted solutions was also determined. The analytical results indicated that the crop, paddy and natural soils in many sampling sites were enriched with Cd and Pb. Furthermore, heavy metal enrichment was most significant in the crop soils, which might be attributed to the use of agrochemicals. Flooding of the paddy soils and subsequent dissolution of Mn oxides may cause the loss of Cd and Co through leaching and percolation, resulting in low Cd and Co concentrations of the paddy soils. The chemical partitioning patterns of Pb, Zn and Cu indicated that Pb was largely associated with the Fe-Mn oxide and residual fractions, while Zn was predominantly found in the residual phase. A significant percent fraction of Cu was bound in the organic/sulphide and residual phases. Based on the 206Pb/207Pb ratios of the five fractions, it was evident that some of the soils were enriched with anthropogenic Pb, such as industrial and automobile Pb. The strong associations between anthropogenic Pb and the Fe-Mn oxide and organic/sulphide phases suggested that anthropogenic Pb was relatively stable after deposition in soils. PMID:12125727

  15. Comparing REE distribution in GEMAS agricultural soils and FOREGS topsoils-subsoils in Italy and Sweden

    NASA Astrophysics Data System (ADS)

    Petrosino, Paola; Sadeghi, Martiya; Andersson, Madelen; Albanese, Stefano; Dinelli, Enrico; Valera, Paolo; Ladenberger, Anna; Morris, George; Uhlbäck, Jo; Lima, Annamaria; De Vivo, Benedetto

    2014-05-01

    Scientific interest on Rare Earth Elements (REEs)-bearing media is increasing as a consequence of the rapidly growing demand of these important chemical resources, which are currently used in a large number of technical applications. In this study, Italian and Swedish REE data from the FOREGS database on topsoil and subsoils samples have been compared to the distribution of REEs in the GEMAS samples of agricultural soil (Ap), pertaining to regularly ploughed land to a depth of 20 cm. Principal Component Analysis (PCA) was carried out to identify patterns within both data sets. Investigation of the spatial distribution of REEs in FOREGS topsoil-subsoil and GEMAS Ap media for both countries revealed the prominent role of the geogenic component in the general REE geochemical pattern of the three solid media. Despite a similar REE content in the underlying parent material or bedrocks (alkaline igneous rocks, both intrusive and effusive in Italy, alkaline granites and pegmatites in Sweden), several distinct differences emerged between the two countries driven by climate, topography, age of the rock units and sediments, presence of mineralisations, type of soils and presence of glacial deposits. GEMAS agricultural soils form both countries show higher REEs contents than the corresponding subsoils and topsoils, which could be ascribed to the analytical method specifically set for REEs and the last generation ICP-MS instrument used by SGS Lab to analyze REEs in Ap soils. The REE content in Italian topsoil and subsoil is similar and there is a good agreement between the topsoils and Ap soils, which were collected from similar depth. Swedish subsoil is on the contrary more enriched in REEs with respect to topsoil, and Ap soils even display REE contents higher than subsoils. This anomalous REE concentrations in agricultural soil may originate from the fact that most of the arable land in Sweden has been located on glacial and postglacial deposits, rich in clay which has

  16. The influence of facility agriculture production on phthalate esters distribution in black soils of northeast China.

    PubMed

    Zhang, Ying; Wang, Pengjie; Wang, Lei; Sun, Guoqiang; Zhao, Jiaying; Zhang, Hui; Du, Na

    2015-02-15

    The current study investigates the existence of 15 phthalate esters (PAEs) in surface soils (27 samples) collected from 9 different facility agriculture sites in the black soil region of northeast China, during the process of agricultural production (comprising only three seasons spring, summer and autumn). Concentrations of the 15 PAEs detected significantly varied from spring to autumn and their values ranged from 1.37 to 4.90 mg/kg-dw, with a median value of 2.83 mg/kg-dw. The highest concentration of the 15 PAEs (4.90 mg/kg-dw) was determined in summer when mulching film was used in the greenhouses. Probably an increase in environmental temperature was a major reason for PAE transfer from the mulching film into the soil and coupled with the increased usage of chemical fertilizers in greenhouses. Results showed that of the 15 PAEs, di(2-ethylhexyl) phthalate(DEHP), di-n-butyl phthalate (DBP), diethyl phthalate (DEP) and dimethyl phthalate (DMP) were in abundance with the mean value of 1.12 ± 0.22, 0.46 ± 0.05, 0.36 ± 0.04, and 0.17 ± 0.01 mg/kg-dw, respectively; and their average contributions in spring, summer, and autumn ranged between 64.08 and 90.51% among the 15 PAEs. The results of Principal Component Analysis (PCA) indicated the concentration of these four main PAEs significantly differed among the facility agricultures investigated, during the process of agricultural production. In comparison with foreign and domestic results of previous researches, it is proved that the black soils of facility agriculture in northeast China show higher pollution situation comparing with non-facility agriculture soils.

  17. Carbon amendment and soil depth affect the distribution and abundance of denitrifiers in agricultural soils.

    PubMed

    Barrett, M; Khalil, M I; Jahangir, M M R; Lee, C; Cardenas, L M; Collins, G; Richards, K G; O'Flaherty, V

    2016-04-01

    The nitrite reductase (nirS and nirK) and nitrous oxide reductase-encoding (nosZ) genes of denitrifying populations present in an agricultural grassland soil were quantified using real-time polymerase chain reaction (PCR) assays. Samples from three separate pedological depths at the chosen site were investigated: horizon A (0-10 cm), horizon B (45-55 cm), and horizon C (120-130 cm). The effect of carbon addition (treatment 1, control; treatment 2, glucose-C; treatment 3, dissolved organic carbon (DOC)) on denitrifier gene abundance and N2O and N2 fluxes was determined. In general, denitrifier abundance correlated well with flux measurements; nirS was positively correlated with N2O, and nosZ was positively correlated with N2 (P < 0.03). Denitrifier gene copy concentrations per gram of soil (GCC) varied in response to carbon type amendment (P < 0.01). Denitrifier GCCs were high (ca. 10(7)) and the bac:nirK, bac:nirS, bac:nir (T) , and bac:nosZ ratios were low (ca. 10(-1)/10) in horizon A in all three respective treatments. Glucose-C amendment favored partial denitrification, resulting in higher nir abundance and higher N2O fluxes compared to the control. DOC amendment, by contrast, resulted in relatively higher nosZ abundance and N2 emissions, thus favoring complete denitrification. We also noted soil depth directly affected bacterial, archaeal, and denitrifier abundance, possibly due to changes in soil carbon availability with depth.

  18. Digital spatial soil and land information for agriculture development

    NASA Astrophysics Data System (ADS)

    Sharma, R. K.; Laghathe, Pankaj; Meena, Ranglal; Barman, Alok Kumar; Das, Satyendra Nath

    2006-12-01

    Natural resource management calls for study of natural system prevailing in the country. In India floods and droughts visit regularly, causing extensive damages of natural wealth including agriculture that are crucial for sustenance of economic growth. The Indian Sub-continent drained by many major rivers and their tributaries where watershed, the hydrological unit forms a natural system that allows management and development of land resources following natural harmony. Acquisition of various kinds and levels of soil and land characteristics using both conventional and remote sensing techniques and subsequent development of digital spatial data base are essential to evolve strategy for planning watershed development programmes, their monitoring and impact evaluation. The multi-temporal capability of remote sensing sensors helps to update the existing data base which are of dynamic in nature. The paper outlines the concept of spatial data base development, generation using remote sensing techniques, designing of data structure, standardization and integration with watershed layers and various non spatial attribute data for various applications covering watershed development planning, alternate land use planning, soil and water conservation, diversified agriculture practices, generation of soil health card, soil and land reclamation, etc. The soil and land characteristics are vital to derive various interpretative groupings or master table that helps to generate the desired level of information of various clients using the GIS platform. The digital spatial data base on soils and watersheds generated by All India Soil and Land Use Survey will act as a sub-server of the main GIS based Web Server being hoisted by the planning commission for application of spatial data for planning purposes under G2G domain. It will facilitate e-governance for natural resource management using modern technology.

  19. Low occurrence of Pseudomonas aeruginosa in agricultural soils with and without organic amendment.

    PubMed

    Deredjian, Amélie; Colinon, Céline; Hien, Edmond; Brothier, Elisabeth; Youenou, Benjamin; Cournoyer, Benoit; Dequiedt, Samuel; Hartmann, Alain; Jolivet, Claudy; Houot, Sabine; Ranjard, Lionel; Saby, Nicolas P A; Nazaret, Sylvie

    2014-01-01

    The occurrence of Pseudomonas aeruginosa was monitored at a broad spatial scale in French agricultural soils, from various soil types and under various land uses to evaluate the ability of soil to be a natural habitat for that species. To appreciate the impact of agricultural practices on the potential dispersion of P. aeruginosa, we further investigated the impact of organic amendment at experimental sites in France and Burkina Faso. A real-time quantitative PCR (qPCR) approach was used to analyze a set of 380 samples selected within the French RMQS ("Réseau de Mesures de la Qualité des Sols") soil library. In parallel, a culture-dependent approach was tested on a subset of samples. The results showed that P. aeruginosa was very rarely detected suggesting a sporadic presence of this bacterium in soils from France and Burkina Faso, whatever the structural and physico-chemical characteristics or climate. When we analyzed the impact of organic amendment on the prevalence of P. aeruginosa, we found that even if it was detectable in various manures (at levels from 10(3) to 10(5) CFU or DNA targets (g drywt)(-1) of sample), it was hardly ever detected in the corresponding soils, which raises questions about its survival. The only case reports were from a vineyard soil amended with a compost of mushroom manure in Burgundy, and a few samples from two fields amended with raw urban wastes in the sub-urban area of Ouagadougou, Burkina Faso. In these soils the levels of culturable cells were below 10 CFU (g drywt)(-1).

  20. Low occurrence of Pseudomonas aeruginosa in agricultural soils with and without organic amendment

    PubMed Central

    Deredjian, Amélie; Colinon, Céline; Hien, Edmond; Brothier, Elisabeth; Youenou, Benjamin; Cournoyer, Benoit; Dequiedt, Samuel; Hartmann, Alain; Jolivet, Claudy; Houot, Sabine; Ranjard, Lionel; Saby, Nicolas P. A.; Nazaret, Sylvie

    2014-01-01

    The occurrence of Pseudomonas aeruginosa was monitored at a broad spatial scale in French agricultural soils, from various soil types and under various land uses to evaluate the ability of soil to be a natural habitat for that species. To appreciate the impact of agricultural practices on the potential dispersion of P. aeruginosa, we further investigated the impact of organic amendment at experimental sites in France and Burkina Faso. A real-time quantitative PCR (qPCR) approach was used to analyze a set of 380 samples selected within the French RMQS (“Réseau de Mesures de la Qualité des Sols”) soil library. In parallel, a culture-dependent approach was tested on a subset of samples. The results showed that P. aeruginosa was very rarely detected suggesting a sporadic presence of this bacterium in soils from France and Burkina Faso, whatever the structural and physico-chemical characteristics or climate. When we analyzed the impact of organic amendment on the prevalence of P. aeruginosa, we found that even if it was detectable in various manures (at levels from 103 to 105 CFU or DNA targets (g drywt)−1 of sample), it was hardly ever detected in the corresponding soils, which raises questions about its survival. The only case reports were from a vineyard soil amended with a compost of mushroom manure in Burgundy, and a few samples from two fields amended with raw urban wastes in the sub-urban area of Ouagadougou, Burkina Faso. In these soils the levels of culturable cells were below 10 CFU (g drywt)−1. PMID:24809025

  1. Comparative resistance and resilience of soil microbial communities and enzyme activities in adjacent native forest and agricultural soils.

    PubMed

    Chaer, Guilherme; Fernandes, Marcelo; Myrold, David; Bottomley, Peter

    2009-08-01

    Degradation of soil properties following deforestation and long-term soil cultivation may lead to decreases in soil microbial diversity and functional stability. In this study, we investigated the differences in the stability (resistance and resilience) of microbial community composition and enzyme activities in adjacent soils under either native tropical forest (FST) or in agricultural cropping use for 14 years (AGR). Mineral soil samples (0 to 5 cm) from both areas were incubated at 40 degrees C, 50 degrees C, 60 degrees C, or 70 degrees C for 15 min in order to successively reduce the microbial biomass. Three and 30 days after the heat shocks, fluorescein diacetate (FDA) hydrolysis, cellulase and laccase activities, and phospholipid-derived fatty acids-based microbial community composition were measured. Microbial biomass was reduced up to 25% in both soils 3 days after the heat shocks. The higher initial values of microbial biomass, enzyme activity, total and particulate soil organic carbon, and aggregate stability in the FST soil coincided with higher enzymatic stability after heat shocks. FDA hydrolysis activity was less affected (more resistance) and cellulase and laccase activities recovered more rapidly (more resilience) in the FST soil relative to the AGR counterpart. In the AGR soil, laccase activity did not show resilience to any heat shock level up to 30 days after the disturbance. Within each soil type, the microbial community composition did not differ between heat shock and control samples at day 3. However, at day 30, FST soil samples treated at 60 degrees C and 70 degrees C contained a microbial community significantly different from the control and with lower biomass regardless of high enzyme resilience. Results of this study show that deforestation followed by long-term cultivation changed microbial community composition and had differential effects on microbial functional stability. Both soils displayed similar resilience to FDA hydrolysis, a

  2. Comparative resistance and resilience of soil microbial communities and enzyme activities in adjacent native forest and agricultural soils.

    PubMed

    Chaer, Guilherme; Fernandes, Marcelo; Myrold, David; Bottomley, Peter

    2009-08-01

    Degradation of soil properties following deforestation and long-term soil cultivation may lead to decreases in soil microbial diversity and functional stability. In this study, we investigated the differences in the stability (resistance and resilience) of microbial community composition and enzyme activities in adjacent soils under either native tropical forest (FST) or in agricultural cropping use for 14 years (AGR). Mineral soil samples (0 to 5 cm) from both areas were incubated at 40 degrees C, 50 degrees C, 60 degrees C, or 70 degrees C for 15 min in order to successively reduce the microbial biomass. Three and 30 days after the heat shocks, fluorescein diacetate (FDA) hydrolysis, cellulase and laccase activities, and phospholipid-derived fatty acids-based microbial community composition were measured. Microbial biomass was reduced up to 25% in both soils 3 days after the heat shocks. The higher initial values of microbial biomass, enzyme activity, total and particulate soil organic carbon, and aggregate stability in the FST soil coincided with higher enzymatic stability after heat shocks. FDA hydrolysis activity was less affected (more resistance) and cellulase and laccase activities recovered more rapidly (more resilience) in the FST soil relative to the AGR counterpart. In the AGR soil, laccase activity did not show resilience to any heat shock level up to 30 days after the disturbance. Within each soil type, the microbial community composition did not differ between heat shock and control samples at day 3. However, at day 30, FST soil samples treated at 60 degrees C and 70 degrees C contained a microbial community significantly different from the control and with lower biomass regardless of high enzyme resilience. Results of this study show that deforestation followed by long-term cultivation changed microbial community composition and had differential effects on microbial functional stability. Both soils displayed similar resilience to FDA hydrolysis, a

  3. Changes in soil oribatid communities associated with conversion from conventional to organic agriculture.

    PubMed

    Khalil, Mohamed A; Al-Assiuty, Abdel-Naieem I M; van Straalen, Nico M; Al-Assiuty, Basma A

    2016-02-01

    We investigated the effects of switching from conventional management to organic management on the abundance and community composition of soil-living oribatid mites in clover fields in an experimental agricultural station at Al-Fayoum, Egypt. The site had two adjacent fields with identical vegetation cover but different management. Fifteen random soil samples were collected monthly from each of three plots per field, from October to March. We characterized the soils with respect to various physicochemical variables as well as fungal community composition, and estimated mite densities through core sampling. Organic fields had a significantly more abundant oribatid community than did conventional fields. Also the abundance of soil fungi was greater in the organically managed field. Organic management promoted common oribatid mite species with a wide ecological amplitude that already had a high abundance where such common species are more responsive to changes in agricultural management. However, some species of mite responded indifferent or negative to the switch from conventional to organic management. Overall, the differences between the two ecological systems were mainly quantitative. Species diversities of both mite and fungal communities did not differ much between the two management systems. Diversity (H0) and equitability (E) of soil oribatid communities were higher in conventional plots than in the organic plots during the first 2 months but indistinguishable thereafter. Our study confirmed that organic management stimulates soilorganic matter build-up, with positive effects on both fungal and oribatid mite abundance and possible long-term effects on soil function.

  4. Sewage sludge applied to agricultural soil: Ecotoxicological effects on representative soil organisms.

    PubMed

    Carbonell, G; Pro, J; Gómez, N; Babín, M M; Fernández, C; Alonso, E; Tarazona, J V

    2009-05-01

    Application of sewage sludge to agricultural lands is a current practice in EU. European legislation permits its use when concentrations of metals in soil do not increase above the maximum permissible limits. In order to assess the fate and the effects on representative soil organisms of sewage sludge amendments on agricultural lands, a soil microcosm (multi-species soil system-MS3) experiment was performed. The MS3 columns were filled with spiked soil at three different doses: 30, 60 and 120tha(-1) fresh wt. Seed plants (Triticum aestivum, Vicia sativa and Brassica rapa) and earthworms (Eisenia fetida) were introduced into the systems. After a 21-d exposure period, a statistically significant increase for Cd, Cu, Zn and Hg concentrations was found for the soils treated with the highest application rate. Dose-related increase was observed for nickel concentrations in leachates. Plants and earthworm metal body burden offer much more information than metal concentrations and help to understand the potential for metal accumulation. Bioaccumulation factor (BAF(plant-soil)) presented a different behavior among species and large differences for BAF(earthworm-soil), from control or sewage-amended soil, for Cd and Hg were found. B. rapa seed germination was reduced. Statistically significant decrease in fresh biomass was observed for T. aestivum and V. sativa at the highest application rate, whereas B. rapa biomass decreased at any application rate. Enzymatic activities (dehydrogenase and phosphatase) as well as respiration rate on soil microorganisms were enlarged.

  5. Effects of different agricultural managements in soil microbial community structure in a semi-arid Mediterranean region.

    NASA Astrophysics Data System (ADS)

    García-Orenes, Fuensanta; Morugan, Alicia; Mataix-Solera, Jorge; Scow, Kate

    2013-04-01

    Agriculture has been practiced in semi-arid Mediterranean regions for 10.000 years and in many cases these practices have been unsuitable causing land degradation for millennium and an important loss of soil quality. The land management can provide solutions to find the best agricultural practices in order to maintain the soil quality and get a sustainable agriculture model. Microbiological properties are the most sensitive and rapid indicators of soil perturbations and land use managements. The study of microbial community and diversity has an important interest as indicators of changes in soil quality. The main objective of this work was to asses the effect of different agricultural management practices in soil microbial community (evaluated as abundance of phospholipid fatty acids, PLFA). Four different treatments were selected, based on the most commonly practices applied by farmers in the study area, "El Teularet Experimental Station", located at the Enguera Range in the southern part of the Valencia province (eastern Spain). These treatments were: a) ploughing, b) herbicides c) mulch, using the types applied by organic farmers to develop a sustainable agriculture, such as oat straw and d) control that was established as plot where the treatment was abandonment after farming. An adjacent area with the same type of soil, but with natural vegetation was used as a standard or reference high quality soil. Soil samples were taken to evaluate the changes in microbial soil structure, analysing the abundance of PLFA. The results showed a major content of total PLFA in soils treated with oats straw, being these results similar to the content of PLFA in the soil with natural vegetation, also these soils were similar in the distribution of abundance of different PLFA studied. However, the herbicide and tillage treatments showed great differences regarding the soil used as reference (soil under natural vegetation).

  6. Estimating the distribution of radionuclides in agricultural soils - dependence on soil parameters.

    PubMed

    Hormann, Volker; Fischer, Helmut W

    2013-10-01

    In this study it is shown how radionuclide distributions in agricultural soils and their dependence on soil parameters can be quantitatively estimated. The most important sorption and speciation processes have been implemented into a numerical model using the geochemical code PHREEQC that is able to include specific soil and soil solution compositions. Using this model, distribution coefficients (Kd values) for the elements Cs, Ni, U and Se have been calculated for two different soil types. Furthermore, the dependencies of these Kd values on various soil parameters (e.g. pH value or organic matter content) have been evaluated. It is shown that for each element, an individual set of soil parameters is relevant for its solid-liquid distribution. The model may be used for the calculation of input parameters used by reference biosphere models (e.g. used for the risk assessment of nuclear waste repositories). PMID:23871968

  7. Estimating the distribution of radionuclides in agricultural soils - dependence on soil parameters.

    PubMed

    Hormann, Volker; Fischer, Helmut W

    2013-10-01

    In this study it is shown how radionuclide distributions in agricultural soils and their dependence on soil parameters can be quantitatively estimated. The most important sorption and speciation processes have been implemented into a numerical model using the geochemical code PHREEQC that is able to include specific soil and soil solution compositions. Using this model, distribution coefficients (Kd values) for the elements Cs, Ni, U and Se have been calculated for two different soil types. Furthermore, the dependencies of these Kd values on various soil parameters (e.g. pH value or organic matter content) have been evaluated. It is shown that for each element, an individual set of soil parameters is relevant for its solid-liquid distribution. The model may be used for the calculation of input parameters used by reference biosphere models (e.g. used for the risk assessment of nuclear waste repositories).

  8. Interactive effects of agricultural management and topography on soil carbon sequestration

    NASA Astrophysics Data System (ADS)

    Ladoni, M.; Kravchenko, S.; Munoz, J.; Erickson, M.

    2012-12-01

    Proper agricultural management scenarios such as no-tillage, cover cropping, agroforestry, have demonstrated potential to increase the amount of carbon sequestered in soil and to mitigate atmospheric carbon levels. The knowledge about positive effects of cover cropping comes mostly from small uniform experimental plots, but whether these positive effects will exists in large scale fields with diverse topography and what would be the magnitude of these effects on a field scale remains to be seen. Our objective is to compare performance of different agricultural managements including those with cover crops in their influences on SOC across diverse topographical landscape in large agricultural fields. The three studied agricultural practices are Conventionally tilled and fertilized management without cover crops (T1), Low-input management with reduced chemical inputs (T3) and Organic (T4) management, the latter two have rye and red clover cover crops as part of their rotations. Within each field 1- 4 transects with three topographical positions of "depression", "slope" and "summit" were identified. The first soil sampling was done in spring 2010 and the second set of soil samples were collected from topographical positions during growing season of 2011. Samples were analyzed for total SOC and also particulate organic carbon (POC) content to show the changes in active pools of SOC. The results showed that topography has a significant influence in performance of cover crops. Agricultural managements with cover crops increased the POC in soil and the magnitude of this increase was different across space. Cover crops built the highest POC in depressions followed by summit and then slope. The conventional agricultural management increased POC in depression but decreased it on slopes. Low-input agricultural management when coupled with cover cropping has a potential to produce the highest increase in active pools of SOC across topographically diverse fields. The ratio of

  9. Single application of Sewage Sludge to an Alluvial Agricultural Soil - impacts on Soil Quality

    NASA Astrophysics Data System (ADS)

    Suhadolc, M.; Graham, D. B.; Hagn, A.; Doerfler, U.; Schloter, M.; Schroll, R.; Munch, J. C.; Lobnik, F.

    2009-04-01

    Limited information exists on the effects of sewage sludge on soil quality with regard to their ability to maintain soil functions. We studied effects of sewage sludge amendment on soil chemical properties, microbial community structure and microbial degradation of the herbicide glyphosate. Three months soil column leaching experiment has been conducted using alluvial soils (Eutric Fluvisol) with no prior history of sludge application. The soil was loamy with pH 7,4 and organic matter content of 3,5%. Soil material in the upper 2 cm of columns was mixed with dehydrated sewage sludge which was applied in amounts corresponding to the standards governing the use of sewage sludge for agricultural land. Sludge did increase some nutrients (total N, NH4+, available P and K, organic carbon) and some heavy metals contents (Zn, Cu, Pb) in soil. However, upper limits for heavy metals in agricultural soils were not exceeded. Results of heavy metal availability in soil determined by sequential extraction will be also presented. Restriction fragment length polymorphism (RFLP) analyses of 16s/18s rDNA, using universal fungal and bacterial primers, revealed clear shifts in bacterial and fungal community structure in the upper 2 cm of soils after amendment. Fungal fingerprints showed greater short term effects of sewage sludge, whereas sewage sludge seems to have prolonged effects on soil bacteria. Furthermore, sewage sludge amendment significantly increased glyphosate degradation from 21.6±1% to 33.6±1% over a 2 months period. The most probable reasons for shifts in microbial community structure and increased degradation of glyphosate are beneficial alterations to the physical-chemical characteristics of the soil. Negative effects of potentially toxic substances present in the sewage sludge on soil microbial community functioning were not observed with the methods used in our study.

  10. Value of Available Global Soil Moisture Products for Agricultural Monitoring

    NASA Astrophysics Data System (ADS)

    Mladenova, Iliana; Bolten, John; Crow, Wade; de Jeu, Richard

    2016-04-01

    The first operationally derived and publicly distributed global soil moil moisture product was initiated with the launch of the Advanced Scanning Microwave Mission on the NASA's Earth Observing System Aqua satellite (AMSR-E). AMSR-E failed in late 2011, but its legacy is continued by AMSR2, launched in 2012 on the JAXA Global Change Observation Mission-Water (GCOM-W) mission. AMSR is a multi-frequency dual-polarization instrument, where the lowest two frequencies (C- and X-band) were used for soil moisture retrieval. Theoretical research and small-/field-scale airborne campaigns, however, have demonstrated that soil moisture would be best monitored using L-band-based observations. This consequently led to the development and launch of the first L-band-based mission-the ESA's Soil Moisture Ocean Salinity (SMOS) mission (2009). In early 2015 NASA launched the second L-band-based mission, the Soil Moisture Active Passive (SMAP). These satellite-based soil moisture products have been demonstrated to be invaluable sources of information for mapping water stress areas, crop monitoring and yield forecasting. Thus, a number of agricultural agencies routinely utilize and rely on global soil moisture products for improving their decision making activities, determining global crop production and crop prices, identifying food restricted areas, etc. The basic premise of applying soil moisture observations for vegetation monitoring is that the change in soil moisture conditions will precede the change in vegetation status, suggesting that soil moisture can be used as an early indicator of expected crop condition change. Here this relationship was evaluated across multiple microwave frequencies by examining the lag rank cross-correlation coefficient between the soil moisture observations and the Normalized Difference Vegetation Index (NDVI). A main goal of our analysis is to evaluate and inter-compare the value of the different soil moisture products derived using L-band (SMOS

  11. 4,4'-DDE and Endosulfan Levels in Agricultural Soils of the Çukurova Region, Mediterranean Turkey.

    PubMed

    Akça, Muhittin Onur; Hisatomi, Shihoko; Takemura, Manami; Harada, Naoki; Nonaka, Masanori; Sakakibara, Futa; Takagi, Kazuhiro; Turgay, Oğuz Can

    2016-03-01

    Mediterranean Turkey has long been at the forefront of Turkish agriculture and the use of organochlorinated pesticides (OCPs) in this area rose considerably between the 1940s and 1980s. This study aimed to determine OCP residue levels in agricultural soils collected from the Mersin and Adana Districts, Çukurova Basin in Mediterranean Turkey. Most soil samples were contaminated with one, or both, of two OCP metabolites; 4,4'-dichlorodiphenyldichloroethylene (4,4'-DDE) and endosulfan sulfate. 4,4'-DDE occurred in 27 of the 29 samples and ranged from 6 to 1090 µg kg(-1)-dry soil (ds)(-1), while six samples contained endosulfan sulfate ranging between 82 and 1226 µg kg(-1)-ds(-1). Generally, horticultural and corn-planted soils contained only 4,4'-DDE, whereas greenhouse cultivation appeared to accumulate both residues. This study indicated that 4,4'-DDE occurred above acceptable levels of risk in agricultural soils of Mersin District and further studies on the qualitative and quantitative assessment of OCPs in other agricultural regions with intensive pesticide use are necessary to fully understand the impact of OCPs on agricultural soil in Turkey. PMID:26687498

  12. Quality evaluation of processed clay soil samples

    PubMed Central

    Steiner-Asiedu, Matilda; Harrison, Obed Akwaa; Vuvor, Frederick; Tano-Debrah, Kwaku

    2016-01-01

    Introduction This study assessed the microbial quality of clay samples sold on two of the major Ghanaian markets. Methods The study was a cross-sectional assessing the evaluation of processed clay and effects it has on the nutrition of the consumers in the political capital town of Ghana. The items for the examination was processed clay soil samples. Results Staphylococcus spp and fecal coliforms including Klebsiella, Escherichia, and Shigella and Enterobacterspp were isolated from the clay samples. Samples from the Kaneshie market in Accra recorded the highest total viable counts 6.5 Log cfu/g and Staphylococcal count 5.8 Log cfu/g. For fecal coliforms, Madina market samples had the highest count 6.5 Log cfu/g and also recorded the highest levels of yeast and mould. For Koforidua, total viable count was highest in the samples from the Zongo market 6.3 Log cfu/g. Central market samples had the highest count of fecal coliforms 4.6 Log cfu/g and yeasts and moulds 6.5 Log cfu/g. “Small” market recorded the highest staphylococcal count 6.2 Log cfu/g. The water activity of the clay samples were low, and ranged between 0.65±0.01 and 0.66±0.00 for samples collected from Koforidua and Accra respectively. Conclusion The clay samples were found to contain Klebsiella spp. Escherichia, Enterobacter, Shigella spp. staphylococcus spp., yeast and mould. These have health implications when consumed.

  13. Quality evaluation of processed clay soil samples

    PubMed Central

    Steiner-Asiedu, Matilda; Harrison, Obed Akwaa; Vuvor, Frederick; Tano-Debrah, Kwaku

    2016-01-01

    Introduction This study assessed the microbial quality of clay samples sold on two of the major Ghanaian markets. Methods The study was a cross-sectional assessing the evaluation of processed clay and effects it has on the nutrition of the consumers in the political capital town of Ghana. The items for the examination was processed clay soil samples. Results Staphylococcus spp and fecal coliforms including Klebsiella, Escherichia, and Shigella and Enterobacterspp were isolated from the clay samples. Samples from the Kaneshie market in Accra recorded the highest total viable counts 6.5 Log cfu/g and Staphylococcal count 5.8 Log cfu/g. For fecal coliforms, Madina market samples had the highest count 6.5 Log cfu/g and also recorded the highest levels of yeast and mould. For Koforidua, total viable count was highest in the samples from the Zongo market 6.3 Log cfu/g. Central market samples had the highest count of fecal coliforms 4.6 Log cfu/g and yeasts and moulds 6.5 Log cfu/g. “Small” market recorded the highest staphylococcal count 6.2 Log cfu/g. The water activity of the clay samples were low, and ranged between 0.65±0.01 and 0.66±0.00 for samples collected from Koforidua and Accra respectively. Conclusion The clay samples were found to contain Klebsiella spp. Escherichia, Enterobacter, Shigella spp. staphylococcus spp., yeast and mould. These have health implications when consumed. PMID:27642456

  14. Geomorphic Controls of Soil and Carbon Redistribution Across an Agricultural Landscape

    NASA Astrophysics Data System (ADS)

    Ritchie, J. C.; McCarty, G. W.; Venteris, E. R.; Kaspar, T. C.

    2006-12-01

    Patterns of soil organic carbon (SOC) vary widely across the landscape leading to large uncertainties in the SOC budget especially for agricultural landscapes where water, tillage, and wind erosion redistributes soil and SOC. It is often assumed that soil erosion results in a loss of SOC from the agricultural ecosystem but recent studies indicate that soil erosion and its subsequent redistribution within fields can stimulate SOC sequestration in agricultural fields. This study investigates the relationship between soil and SOC redistribution patterns in relationship to geomorphic position in two tilled agricultural fields using the fallout Cesium-137 technique to measure soil redistribution. Cesium-137 and SOC concentrations in agricultural soils are significantly correlated in our study areas. Hillslope areas (eroding) have significantly less SOC than soils in toe slope areas (deposition). SOC decreased as gradient slope increases and soils on concave slopes had higher SOC than soils on convex slopes. These data suggest that soil redistribution patterns and topographic patterns may be used to help understand SOC dynamics on agricultural landscapes. Different productivity and oxidation rates of SOC of eroded versus deposited soils also contribute to SOC spatial patterns. However, the strong significant relationships between the patterns of soil redistribution and SOC concentrations in agricultural soils suggest that they are moving along similar physical pathways in these systems. Our study also indicates that geomorphic position is important for understanding soil and SOC movement and redistribution patterns within a field or watershed. Such information can help develop and implement management systems to increase SOC in agricultural ecosystems.

  15. Occurrence of Stenotrophomonas maltophilia in agricultural soils and antibiotic resistance properties.

    PubMed

    Deredjian, Amélie; Alliot, Nolwenn; Blanchard, Laurine; Brothier, Elisabeth; Anane, Makram; Cambier, Philippe; Jolivet, Claudy; Khelil, Mohamed Naceur; Nazaret, Sylvie; Saby, Nicolas; Thioulouse, Jean; Favre-Bonté, Sabine

    2016-05-01

    The occurrence of Stenotrophomonas maltophilia was monitored in organic amendments and agricultural soils from various sites in France and Tunisia. S. maltophilia was detected in horse and bovine manures, and its abundance ranged from 0.294 (±0.509) × 10(3) to 880 (±33.4) × 10(3) CFU (g drywt)(-1) of sample. S. maltophilia was recovered from most tested soil samples (104/124). Its abundance varied from 0.33 (±0.52) to 414 (±50) × 10(3) CFU (g drywt)(-1) of soil and was not related to soil characteristics. Antibiotic resistance properties of a set of environmental strains were compared to a clinical set, and revealed a high diversity of antibiotic resistance profiles, given both the numbers of resistance and the phenotypes. Manure strains showed resistance phenotypes, with most of the strains resisting between 7 and 9 antibiotics. While French soil strains were sensitive to most antibiotics tested, some Tunisian strains displayed resistance phenotypes close to those of clinical French strains. Screening for metal resistance among 66 soil strains showed a positive relationship between antibiotic and metal resistance. However, the prevalence of antibiotic resistance phenotypes in the studied sites was not related to the metal content in soil samples.

  16. Ranking factors affecting emissions of GHG from incubated agricultural soils

    PubMed Central

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

    2014-01-01

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

  17. Ranking factors affecting emissions of GHG from incubated agricultural soils.

    PubMed

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

    2014-07-01

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

  18. Effect of integrating straw into agricultural soils on soil infiltration and evaporation.

    PubMed

    Cao, Jiansheng; Liu, Changming; Zhang, Wanjun; Guo, Yunlong

    2012-01-01

    Soil water movement is a critical consideration for crop yield in straw-integrated fields. This study used an indoor soil column experiment to determine soil infiltration and evaporation characteristics in three forms of direct straw-integrated soils (straw mulching, straw mixing and straw inter-layering). Straw mulching is covering the land surface with straw. Straw mixing is mixing straw with the top 10 cm surface soil. Then straw inter-layering is placing straw at the 20 cm soil depth. There are generally good correlations among the mulch integration methods at p < 0.05, and with average errors/biases <10%. Straw mixing exhibited the best effect in terms of soil infiltration, followed by straw mulching. Due to over-burden weight-compaction effect, straw inter-layering somehow retarded soil infiltration. In terms of soil water evaporation, straw mulching exhibited the best effect. This was followed by straw mixing and then straw inter-layering. Straw inter-layering could have a long-lasting positive effect on soil evaporation as it limited the evaporative consumption of deep soil water. The responses of the direct straw integration modes to soil infiltration and evaporation could lay the basis for developing efficient water-conservation strategies. This is especially useful for water-scarce agricultural regions such as the arid/semi-arid regions of China.

  19. Effect of integrating straw into agricultural soils on soil infiltration and evaporation.

    PubMed

    Cao, Jiansheng; Liu, Changming; Zhang, Wanjun; Guo, Yunlong

    2012-01-01

    Soil water movement is a critical consideration for crop yield in straw-integrated fields. This study used an indoor soil column experiment to determine soil infiltration and evaporation characteristics in three forms of direct straw-integrated soils (straw mulching, straw mixing and straw inter-layering). Straw mulching is covering the land surface with straw. Straw mixing is mixing straw with the top 10 cm surface soil. Then straw inter-layering is placing straw at the 20 cm soil depth. There are generally good correlations among the mulch integration methods at p < 0.05, and with average errors/biases <10%. Straw mixing exhibited the best effect in terms of soil infiltration, followed by straw mulching. Due to over-burden weight-compaction effect, straw inter-layering somehow retarded soil infiltration. In terms of soil water evaporation, straw mulching exhibited the best effect. This was followed by straw mixing and then straw inter-layering. Straw inter-layering could have a long-lasting positive effect on soil evaporation as it limited the evaporative consumption of deep soil water. The responses of the direct straw integration modes to soil infiltration and evaporation could lay the basis for developing efficient water-conservation strategies. This is especially useful for water-scarce agricultural regions such as the arid/semi-arid regions of China. PMID:22643418

  20. Soil Management Effects on Gas Fluxes from an Organic Soil Agricultural System

    NASA Astrophysics Data System (ADS)

    Jennewein, S. P.; Bhadha, J. H.; Lang, T. A.; Singh, M.; Daroub, S. H.; McCray, M.

    2015-12-01

    The role of soil management on gas flux isn't well understood for Histosols of the Everglades Agricultural Area (EAA) of southern Florida. The region is responsible for roughly half of sugarcane (Saccharum spp. hybrids) production in the USA along with supplying winter vegetable crops to the eastern USA. Future productivity in the EAA is jeopardized by soil subsidence resulting from oxidation of organic matter. Establishing the role of tillage, water-table depth, nitrogen fertilizer, and soil depth on gas flux will help determine how effective various managements are on conserving soil. Ongoing lysimeter and field studies examined effects of management practices (water-table, tillage, and nitrogen fertilizer), and soil depth on, gas emission and microbial biomass. The trials were set in Belle Glade, FL, on Lauderhill muck (Lithic Haplosaprists). Results to be presented include soil microbial biomass and soil gas (CO2, CH4, and N2O) flux. This study provides insight into management effectiveness and agriculture sustainability on shallow muck soils of the EAA and will help farmers mitigate problems associated with soil subsidence and seasonally high water-tables.

  1. Fate and availability of glyphosate and AMPA in agricultural soil.

    PubMed

    Simonsen, Louise; Fomsgaard, Inge S; Svensmark, Bo; Spliid, Niels Henrik

    2008-06-01

    The fate of glyphosate and its degradation product aminomethylphosphonic acid (AMPA) was studied in soil. Labeled glyphosate was used to be able to distinguish the measured quantities of glyphosate and AMPA from the background values since the soil was sampled in a field where glyphosate had been used formerly. After addition of labeled glyphosate, the disappearance of glyphosate and the formation and disappearance of AMPA were monitored. The resulting curves were fitted according to a new EU guideline. The best fit of the glyphosate degradation data was obtained using a first-order multi compartment (FOMC) model. DT(50) values of 9 days (glyphosate) and 32 days (AMPA) indicated relatively rapid degradation. After an aging period of 6 months, the leaching risk of each residue was determined by treating the soil with pure water or a phosphate solution (pH 6), to simulate rain over a non-fertilized or fertilized field, respectively. Significantly larger (p < 0.05) amounts of aged glyphosate and AMPA were extracted from the soil when phosphate solution was used as an extraction agent, compared with pure water. This indicates that the risk of leaching of aged glyphosate and AMPA residues from soil is greater in fertilized soil. The blank soil, to which 252 g glyphosate/ha was applied 21 months before this study, contained 0.81 ng glyphosate/g dry soil and 10.46 ng AMPA/g dry soil at the start of the study. Blank soil samples were used as controls without glyphosate addition. After incubation of the blank soil samples for 6 months, a significantly larger amount of AMPA was extracted from the soil treated with phosphate solution than from that treated with pure water. To determine the degree of uptake of aged glyphosate residues by crops growing in the soil, (14)C-labeled glyphosate was applied to soil 6.5 months prior to sowing rape and barley seeds. After 41 days, 0.006 +/- 0.002% and 0.005 +/- 0.001% of the applied radioactivity was measured in rape and barley

  2. Utilizing of magnetic parameters for evaluation of soil erosion rates on two different agricultural sites

    NASA Astrophysics Data System (ADS)

    Kapicka, A.; Grison, H.; Petrovsky, E.; Jaksik, O.; Kodesova, R.

    2015-12-01

    Field measurements of magnetic susceptibility were carried out on regular grid, resulting in 101 data points at Brumovice and 65 at Vidim locality. Mass specific magnetic susceptibility χ and its frequency dependence χFD was used to estimate the significance of SP ferrimagnetic particles of pedogenic origin in topsoil horizons. The lowest magnetic susceptibility was obtained on the steep valley sides. Here the original topsoil was eroded and mixed by tillage with the soil substrate (loess). Soil profiles unaffected by erosion were investigated in detail. The vertical distribution of magnetic susceptibility along these "virgin" profiles was measured in laboratory on samples collected with 2-cm spacing. The differences between the distribution of susceptibility in the undisturbed soil profiles and the magnetic signal after uniform mixing of the soil material as a result of erosion and tillage are fundamental for the estimation of soil loss in the studied test fields. Maximum cumulative soil erosion depth in Brumovice and Vidim is around 100 cm and 50 cm respectively. The magnetic method is suitable for mapping at the chernozem localities and measurement of soil magnetic susceptibility is in this case useful and fast technique for quantitative estimation of soil loss caused by erosion. However, it is less suitable (due to lower magnetic differentiation with depth) in areas with luvisol as dominant soil unit. Acknowledgement: This study was supported by NAZV Agency of the Ministry of Agriculture of the Czech Republic through grant No QJ1230319.

  3. Survey of heavy metal pollution and assessment of agricultural soil in Yangzhong district, Jiangsu Province, China.

    PubMed

    Huang, S S; Liao, Q L; Hua, M; Wu, X M; Bi, K S; Yan, C Y; Chen, B; Zhang, X Y

    2007-05-01

    We investigated concentrations of Hg, Cd, Pb, Zn, Cu, As, Ni, and Cr in samples of soil, cereal, and vegetables from Yangzhong district, China. Compared to subsoils, the sampled topsoils are enriched in Hg, Cd, Cu, Pb, Zn, and As. High levels of Cd and Hg are observed in most agricultural soils. Concentrations of Cr and Ni show little spatial variation, and high Cu, Pb, and Zn contents correspond well to areas of urban development. High As contents are primarily recorded at the two ends of the sampled alluvion. The contents of Cd, Hg, and total organic carbon (TOC) increase gradually to maximum values in the upper parts of soil profiles, while Cr and Ni occur in low concentrations within sampled profiles. As, Pb, Cu, and Zn show patterns of slight enrichment within the surface layer. Compared to data obtained in 1990, Cd and Hg show increased concentrations in 2005; this is attributed to the long-term use of agrochemicals. Cr and Ni contents remained steady over this interval because they are derived from the weathering of parent material and subsequent pedogenesis. The measured As, Cu, Pb, and Zn contents show slight increases over time due to atmospheric deposition of material sourced from urban anthropogenic activity. Low concentrations of heavy metals are recorded in vegetables and cereals because the subalkaline environment of the soil limits their mobility. Although the heavy metal concentrations measured in this study do not pose a serious health risk, they do affect the quality of agricultural products.

  4. [Improving Agricultural Safety of Soils Contaminated with Polycyclic Aromatic Hydrocarbons by In Situ Bioremediation].

    PubMed

    Jiao, Hai-huan; Pan, Jian-gang; Xu, Shena-jun; Bai, Zhi-hui; Wang, Dong; Huang, Zhan-bin

    2015-08-01

    In order to reduce the risk of enrichment of polycyclic aromatic hydrocarbons (PAHs) in crops, reduce the potential hazards of food-sourced PAHs to human and increase the agricultural safety of PAHs contaminated soils, the bio-augmented removal of polycyclic aromatic hydrocarbons (PAHs) was investigated through in situ remediation by introducing Rhodobacter sphaeroides (RS) into the agricultural soil contaminated by PAHs. The 50-times diluted RS was sprayed on leaf surface (in area B) or irrigated to roots (in area D). The treatment of spraying water of the equal amount was taken as the control (A) and the wheat field without any treatment as the blank (CK). Treatments were conducted since wheat seeding. Soil and wheat samples were collected in the mature period to analyze the changes of community structure of the soil microorganisms and the concentration of PAHs in soils and investigate the strengthening and restoration effects of RS on PAHs contaminated soils. Compared to the CK Area, the areas B and D revealed that the variation ratio of phospholipid fatty acids (PLFAs) that were the biomarker of soil microorganisms was 29.6%, and the ratio of total PAHs removed was increased 1.59 times and 1.68 times, respectively. The dry weight of wheat grain of 50 spikes was increased by 8.95% and 12.5%, respectively, and the enrichment factor of total PAHs was decreased by 58.9% and 62.2% respectively in the wheat grains. All the results suggested that RS reduced enrichment of PAHs in wheat grains and increased wheat yield, which had great exploitation and utilization potentiality in repairing and improving the agricultural safety of the soils contaminated with PHAs.

  5. A new baseline of organic carbon stock in European agricultural soils using a modelling approach.

    PubMed

    Lugato, Emanuele; Panagos, Panos; Bampa, Francesca; Jones, Arwyn; Montanarella, Luca

    2014-01-01

    Proposed European policy in the agricultural sector will place higher emphasis on soil organic carbon (SOC), both as an indicator of soil quality and as a means to offset CO2 emissions through soil carbon (C) sequestration. Despite detailed national SOC data sets in several European Union (EU) Member States, a consistent C stock estimation at EU scale remains problematic. Data are often not directly comparable, different methods have been used to obtain values (e.g. sampling, laboratory analysis) and access may be restricted. Therefore, any evolution of EU policies on C accounting and sequestration may be constrained by a lack of an accurate SOC estimation and the availability of tools to carry out scenario analysis, especially for agricultural soils. In this context, a comprehensive model platform was established at a pan-European scale (EU + Serbia, Bosnia and Herzegovina, Croatia, Montenegro, Albania, Former Yugoslav Republic of Macedonia and Norway) using the agro-ecosystem SOC model CENTURY. Almost 164 000 combinations of soil-climate-land use were computed, including the main arable crops, orchards and pasture. The model was implemented with the main management practices (e.g. irrigation, mineral and organic fertilization, tillage) derived from official statistics. The model results were tested against inventories from the European Environment and Observation Network (EIONET) and approximately 20 000 soil samples from the 2009 LUCAS survey, a monitoring project aiming at producing the first coherent, comprehensive and harmonized top-soil data set of the EU based on harmonized sampling and analytical methods. The CENTURY model estimation of the current 0-30 cm SOC stock of agricultural soils was 17.63 Gt; the model uncertainty estimation was below 36% in half of the NUTS2 regions considered. The model predicted an overall increase of this pool according to different climate-emission scenarios up to 2100, with C loss in the south and east of the area

  6. Organic Phosphorus Characterisation in Agricultural Soils by Enzyme Addition Assays

    NASA Astrophysics Data System (ADS)

    Jarosch, Klaus; Frossard, Emmanuel; Bünemann, Else K.

    2013-04-01

    Phosphorus (P) is a non-renewable resource and it is a building block of many molecules indispensable for life. Up to 80 per cent of total soil P can be in organic form. Hydrolysability and thereby availability to plants and microorganisms differ strongly among the multitude of chemical forms of soil organic P. A recent approach to characterise organic P classes is the addition of specific enzymes which hydrolyse organic P to inorganic orthophosphate, making it detectable by colorimetry. Based on the substrate specificity of the added enzymes, conclusions about the hydrolysed forms of organic P can then be made. The aim of this study was to determine the applicability of enzyme addition assays for the characterisation of organic P species in soil:water suspensions of soils with differing properties. To this end, ten different soil samples originating from four continents, with variable pH (in water) values (4.2-8.0), land management (grassland or cropped land) and P fertilization intensity were analysed. Three different enzymes were used (acid phosphatase, nuclease and phytase). Acid phosphatase alone or in combination with nuclease was applied to determine the content of P in simple monoesters (monoester-like P) and P in DNA (DNA-like P), while P hydrolysed from myo-inositol hexakisphosphate (Ins6P-like P) was calculated from P release after incubation with phytase minus P release by acid phosphatase. To reduce sorption of inorganic P on soil particles of the suspension, especially in highly weathered soils, soil specific EDTA additions were determined in extensive pre-tests. The results of these pre-tests showed that recoveries of at least 30 per cent could be achieved in all soils. Thus, detection of even small organic P pools, such as DNA-like P, was possible in all soils if a suitable EDTA concentration was chosen. The enzyme addition assays provided information about the hydrolysable quantities of the different classes of soil organic P compounds as affected

  7. [Characteristics of soil nematode community of different agricultural areas in Jiangsu Province, China].

    PubMed

    Jiao, Jia-guo; Liu, Bei-bei; Mao, Miao; Ye, Cheng-long; Yu, Li; Hu, Feng

    2015-11-01

    This paper investigated the genus diversity of soil nematodes of different agricultural areas in Jiangsu Province, analyzed the relationship between soil nematodes and soil environmental factors, and discussed the roles of soil nematodes as biological indicators of soil health. The results showed that, a total of 41 nematode genera were found in all six agricultural areas, belonging to 19 families, 7 orders, 2 classes. The numbers and community compositions of nematodes were obviously influenced by soil texture, fertilization and tillage practices. In all six agricultural areas, the numbers of nematodes in coastal agricultural area (400 individuals per 100 g dry soil) were significantly larger than that in Xuhuai, Ningzhenyang, and riverside agricultural areas. While the smallest number of nematodes was found in Yanjiang agricultural area (232 individuals per 100 g dry soil), which might be due to the differences in soil texture, annual rainfall and annual air temperature and other factors. The dominant genera of nematodes were similar in the adjacent agricultural areas. Correlation analysis showed that there was a significant positive correlation between the number of soil nematodes and levels of soil nutrients (soil organic matter, total nitrogen, available nitrogen, available potassium and available phosphorus). Redundancy analysis (RDA) indicated the total nitrogen, available potassium and pH obviously affected some soil nematode genera. The analysis of spatial distribution characteristics of soil nematode community in farmland of Jiangsu Province could provide data for health assessment of agricultural ecosystems. PMID:26915207

  8. Agricultural machineries wheeling and soil qualities mapping in climatic changes conditions

    NASA Astrophysics Data System (ADS)

    Bergonzoli, S.; Servadio, P.

    2012-04-01

    As argued in the Fourth Assessment Report of the UN International Panel on Climate Change (IPCC) published in 2007 the global climate is changing and will continue to change in the near future. Due to the changing in time distribution and intensity of rainfall, the available time to carry out soil tillage operations, seedbed preparation and fertilizers distribution is becoming shorter. These issues are worsened by soil compaction that is one of the major problems facing modern agriculture. Soil compaction impedes infiltration of rainfall, so the increasing scale of mechanization might well be responsible for greater runoff, soil loss by water erosion and water-logging. Overuse of machinery, intensive cropping, short crop rotations, intensive grazing and inappropriate soil management leads to compaction. The objective of this research was to study the compacting effect of two wheeled tractors fitted with different type of tires during fertilizing operations with soil water content over field capacity. Field tests were carried out in a farm near Rome (41°52'502'' Latitude (N); 12°12'866" Longitude (E)) in March 2010 on a clay soil (Vertic Cambisol) during wheat fertilizing. One tractor was fitted with very narrow and high aspect ratio tires with mounted broadcaster coded (WTN), the other tractor was equipped with extra large and low aspect ratio tires with trailed broadcaster for a total of four axles coded (WTEL). Immediately after fertilising operations, such effects have been quantified through spatial variation of some soil parameters: soil water content, soil penetration resistance (CI) and soil shear strength (SS). Soil samplings have been carried out on the tracks left by the tractors and on soil not interested by the passage (control). To monitor all tractors passes across the field and to compute the total area covered by tractors tires a DGPS receiver was placed into the tractors; to map soil parameters studied, both on tracks left by the tractors passes

  9. Agricultural soil moisture experiment, Colby, Kansas 1978: Measured and predicted hydrological properties of the soil

    NASA Technical Reports Server (NTRS)

    Arya, L. M. (Principal Investigator)

    1980-01-01

    Predictive procedures for developing soil hydrologic properties (i.e., relationships of soil water pressure and hydraulic conductivity to soil water content) are presented. Three models of the soil water pressure-water content relationship and one model of the hydraulic conductivity-water content relationship are discussed. Input requirements for the models are indicated, and computational procedures are outlined. Computed hydrologic properties for Keith silt loam, a soil typer near Colby, Kansas, on which the 1978 Agricultural Soil Moisture Experiment was conducted, are presented. A comparison of computed results with experimental data in the dry range shows that analytical models utilizing a few basic hydrophysical parameters can produce satisfactory data for large-scale applications.

  10. 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.

  11. The economics of soil C sequestration and agricultural emissions abatement

    NASA Astrophysics Data System (ADS)

    Alexander, P.; Paustian, K.; Smith, P.; Moran, D.

    2015-04-01

    Carbon is a critical component of soil vitality and is crucial to our ability to produce food. Carbon sequestered in soils also provides a further regulating ecosystem service, valued as the avoided damage from global climate change. We consider the demand and supply attributes that underpin and constrain the emergence of a market value for this vital global ecosystem service: markets being what economists regard as the most efficient institutions for allocating scarce resources to the supply and consumption of valuable goods. This paper considers how a potentially large global supply of soil carbon sequestration is reduced by economic and behavioural constraints that impinge on the emergence of markets, and alternative public policies that can efficiently transact demand for the service from private and public sector agents. In essence, this is a case of significant market failure. In the design of alternative policy options, we consider whether soil carbon mitigation is actually cost-effective relative to other measures in agriculture and elsewhere in the economy, and the nature of behavioural incentives that hinder policy options. We suggest that reducing the cost and uncertainties of mitigation through soil-based measures is crucial for improving uptake. Monitoring and auditing processes will also be required to eventually facilitate wide-scale adoption of these measures.

  12. An inventory of trace elements inputs to French agricultural soils.

    PubMed

    Belon, E; Boisson, M; Deportes, I Z; Eglin, T K; Feix, I; Bispo, A O; Galsomies, L; Leblond, S; Guellier, C R

    2012-11-15

    The inputs of ten trace elements (As, Cd, Cu, Cr, Hg, Mo, Ni, Pb, Se, Zn) to French agricultural soils have been assessed. The six main sources considered were: pesticides, mineral fertilizers, animal manure, liming materials, sludge and composts and atmospheric deposition. Data were collected to compute inputs at both national and regional (departmental) scales. The inventory methodology is based on two principles: data are traceable and easy to update. At a national scale, the inventory showed that trace elements inputs can be ranked: Zn≫Cu≫Cr>Pb>Ni>As=Mo>Se>Cd>Hg. Animal manure, mineral fertilizers and pesticides are the predominant sources of TEs. These results are globally in agreement with literature data though atmospheric deposition is shown to be lower than in more industrial countries such as China and United Kingdom where similar surveys were conducted. The inputs of trace elements vary strongly between regions in relation with agricultural activities. This inventory (and the related database) provides basis for developing and monitoring policies to control and reduce trace elements contamination of agricultural soils at both national and regional (departmental) scales.

  13. Directional reflectance factors for monitoring spatial changes in soil surface structure and soil organic matter erosion in agricultural systems

    NASA Astrophysics Data System (ADS)

    Croft, H.; Anderson, K.

    2012-04-01

    Soils can experience rapid structural degradation in response to land cover changes, resulting in reduced soil productivity, increased erodibility and a loss of soil organic matter (SOM). The breakdown of soil aggregates through slaking and raindrop impact is linked to organic matter turnover, with subsequently eroded material often displaying proportionally more SOM. A reduction in aggregate stability is reflected in a decline in soil surface roughness (SSR), indicating that a soil structural change can be used to highlight soil vulnerability to SOM loss through mineralisation or erosion. Accurate, spatially-continuous measurements of SSR are therefore needed at a variety of spatial and temporal scales to understand the spatial nature of SOM erosion and deposition. Remotely-sensed data can provide a cost-effective means of monitoring changes in soil surface condition over broad spatial extents. Previous work has demonstrated the ability of directional reflectance factors to monitor soil crusting within a controlled laboratory experiment, due to changes in the levels of self-shadowing effects by soil aggregates. However, further research is needed to test this approach in situ, where other soil variables may affect measured reflectance factors and to investigate the use of directional reflectance factors for monitoring soil erosion processes. This experiment assesses the potential of using directional reflectance factors to monitor changes in SSR, aggregate stability and soil organic carbon (SOC) content for two agricultural conditions. Five soil plots representing tilled and seedbed soils were subjected to different durations of natural rainfall, producing a range of different levels of SSR. Directional reflectance factors were measured concomitantly with sampling for soil structural and biochemical tests at each soil plot. Soil samples were taken to measure aggregate stability (wet sieving), SOC (loss on ignition) and soil moisture (gravimetric method). SSM

  14. Searsville Sediment Experiment: What is the ideal agricultural soil?

    NASA Astrophysics Data System (ADS)

    Leal, J.; Lo, D.; Patel, N.; Gu, S.

    2014-12-01

    The purpose of this experiment is to decide whether or not the sediment located within Searsville Dam at the Jasper Ridge Biological Preserve is well suited for agricultural soil. By utilizing various combinations of sediment, farm soil, compost, and horse manure to grow basil plants, we underwent an exploratory study in order to better understand what type of materials and nutrients plants can best thrive within. Our general experiment protocol includes watering the crops with irrigation every day while young, and then limiting that water exposure to only Mondays, Wednesdays, and Fridays as they become more established. The basil is growing in pots filled with the different amounts of material, and are arranged randomly to prevent certain plants from getting more sunlight than others. The whole experiment plot is covered with a thin white fabric and secured with bricks and wood to keep out pests in the garden. In order to observe trends in the basil development, plant height and leaf number is recorded once every week. During the third week of the study we performed soil texture tests, and within the fourth week we calculated pH data. We discovered that the sediment our project focuses upon is 10-18% clay and 50% sand which categorizes it as loam, and the Stanford farm soil that serves as our control group contains 20-26% clay and 30% sand so it is a silt loam material. The pH tests also showed an average of 7.45 for sediment, 7.3 for farm soil, 7.85 for compost, and 7.65 for horse manure. By looking at all of the data recorded over the five-week time period, we have so far noticed that the 50% sediment and 50% horse manure combination consistently has the best height increase as well as leaf size and content. The 50% sediment and 50% compost mixture has also performed well in those terms, and is therefore a possibility for the best agricultural soil. However, future lab work conducted by Stanford students to examine the nutrient content of the basil tissue, along

  15. Effects of Conservation Agriculture on Soil Physical Properties and Yield of Lentil in Northern Syria

    NASA Astrophysics Data System (ADS)

    Wahbi, Ammar; Miwak, Hisham; Singh, Raphy

    2014-05-01

    Conservation agriculture (CA) aims to achieve sustainable and profitable agriculture and subsequently improve livelihoods of farmers based on three main components, i.e. minimum or no tillage, retention of crop residues and use of crop rotation. However, to promote CA in semi-arid areas where precipitation is erratic, low, and falls over short periods in winter, its effects on soil and crop yield have to be investigated. The present study was conducted at the main research station of the International Center for Agricultural Research in the Dry Areas (ICARDA), Syria, during the agricultural season of 2010-2011, in the frame of a long term trial (2003-2011), where two treatments; i.e. conservation versus conventional agriculture (replicated twice), and six varieties of lentil (early, medium and late maturity genotypes; 2 each), selected from 100 varieties, were used. Soil samples were taken (before planting and after harvesting), to determine soil bulk density, particle density and total porosity. Aggregate stability was also determined using dry and wet sieving methods for the 0-15 cm soil depth, and the effective diameter of the aggregate was calculated for both treatments of conservation agriculture (CA) and conventional tillage (CT). Soil moisture was monitored in the top soil layer (0-15 cm) using Time Domain Reflectometry (TDR) on a weekly or two weekly-intervals. Soil moisture release curve was done for disturbed, 2 mm dry sieved soil at 0-15, 15-30, 30-45 and 45-60 cm depth using pressure plate chamber. Dry plant production (oven dry at 70°C) was estimated at the harvesting stage, and then threshed to estimate grain yield. CA showed higher (p = 0.001) soil moisture values than CT. The difference in volumetric soil moisture content between CA and CT during the studied period ranged from 20 to 30 %. Volumetric water content was higher for, CA compared with CT, at a given soil water potential especially at the lower pressure; this observation was consistent

  16. The impact of agriculture management on soil quality in citrus orchards in Eastern Spain

    NASA Astrophysics Data System (ADS)

    Hondebrink, Merel; Cerdà, Artemi; Cammeraat, Erik

    2015-04-01

    Currently, the agricultural management of citrus orchard in the Valencia region in E Spain, is changing from traditionally irrigated and managed orchards to drip irrigated organic managed orchards. It is not known what is the effect of such changes on soil quality and hope to shed some light with this study on this transition. It is known that the drip-irrigated orchards built in sloping terrain increase soil erosion (Cerdà et al., 2009; Li et al., 2014) and that agricultural management such as catch crops and mulches reduce sediment yield and surface runoff (Xu et al., 2012; ), as in other orchards around the world (Wang et al., 2010; Wanshnong et al., 2013; Li et al., 2014; Hazarika et al., 2014): We hypothesize that these changes have an important impact on the soil chemical and physical properties. Therefor we studied the soil quality of 12 citrus orchards, which had different land and irrigation management techniques. We compared organic (OR) and conventional (CO) land management with either drip irrigation (DRP) or flood irrigation (FLD). Soil samples at two depths, 0-1 cm and 5-10 cm, were taken for studying soil quality parameters under the different treatments. These parameters included soil chemical parameters, bulk density, texture, soil surface shear strength and soil aggregation. Half of the studied orchards were organically managed and the other 6 were conventionally managed, and for each of these 6 study sites three fields were flood irrigated plots (FLD) and the other three drip irrigated systems (DRP) In total 108 soil samples were taken as well additional irrigation water samples. We will present the results of this study with regard to the impact of the studied irrigation systems and land management systems with regard to soil quality. This knowledge might help in improving citrus orchard management with respect to maintaining or improving soil quality to ensure sustainable agricultural practices. References Cerdà, A., Giménez-Morera, A. and

  17. Levels of PCDD/Fs in agricultural soils near two municipal waste incinerators in Shanghai, China.

    PubMed

    Deng, Y Y; Jia, L J; Li, Kang; Rong, Z Y; Yin, H W

    2011-01-01

    A study was conducted on polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/F) in agricultural soils at 41 sites within a radius of 3 km from two municipal solid waste incinerators in Shanghai. The PCDD/F concentrations ranged from 71.32 to 3,881.44 pg g⁻¹ (0.64-61.15 pg I-TEQ g⁻¹). The highest PCDD/F concentrations were found approximately 1,000 m from the municipal solid waste incinerators. The PCDD/F homologue profiles of all soil samples were compared with the profiles from suspected PCDD/F sources by multivariate statistical analysis. The results showed that, the PCDD/F pollutions in some soil samples can be attributed to emissions from the municipal solid waste incinerators.

  18. Use of Magnetic Parameters to Asses Soil Erosion Rates on Agricultural Site

    NASA Astrophysics Data System (ADS)

    Petrovsky, E.; Kapicka, A.; Dlouha, S.; Jaksik, O.; Grison, H.; Kodesova, R.

    2014-12-01

    A detailed field study on a small test site of agricultural land situated in loess region in Southern Moravia (Czech Republic) and laboratory analyses were carried out in order to test the applicability of magnetic methods in assessing soil erosion. Haplic Chernozem, the original dominant soil unit in the area, is nowadays progressively transformed into different soil units along with intense soil erosion. As a result, an extremely diversified soil cover structure has developed due to the erosion. The site was characterized by a flat upper part while the middle part, formed by a substantive side valley, is steeper. We carried out field measurements of magnetic susceptibility on a regular grid, resulting in 101 data points. The bulk soil material for laboratory investigation was gathered from all the grid points. Values of the magnetic susceptibility are spatially distributed depending on the terrain. Higher values were measured in the flat upper part (where the original top horizon remained). The lowest values of were obtained on the steep valley sides. Here the original topsoil was eroded and mixed by tillage with the soil substrate (loess). A soil profile unaffected by erosion was investigated in detail. The vertical distribution of magnetic susceptibility along this "virgin" profile was measured in laboratory on the samples collected with 2-cm spacing. The undisturbed profile shows several soil horizons. Horizons Ac and A show a slight increase in magnetic susceptibility up to a depth of about 70 cm. Horizon A/Ck is characterized by a decrease in susceptibility, and the underlying C horizon (h > 103 cm) has a very low value of magnetic susceptibility. The differences between the values of susceptibility in the undisturbed soil profile and the magnetic signal after uniform mixing the soil material as a result of tillage and erosion are fundamental for the estimation of soil loss in the studied test field. Using the uneroded profile from the studied locality as a

  19. Modelling the effect of agricultural management practices on soil organic carbon stocks: does soil erosion matter?

    NASA Astrophysics Data System (ADS)

    Nadeu, Elisabet; Van Wesemael, Bas; Van Oost, Kristof

    2014-05-01

    Over the last decades, an increasing number of studies have been conducted to assess the effect of soil management practices on soil organic carbon (SOC) stocks. At regional scales, biogeochemical models such as CENTURY or Roth-C have been commonly applied. These models simulate SOC dynamics at the profile level (point basis) over long temporal scales but do not consider the continuous lateral transfer of sediment that takes place along geomorphic toposequences. As a consequence, the impact of soil redistribution on carbon fluxes is very seldom taken into account when evaluating changes in SOC stocks due to agricultural management practices on the short and long-term. To address this gap, we assessed the role of soil erosion by water and tillage on SOC stocks under different agricultural management practices in the Walloon region of Belgium. The SPEROS-C model was run for a 100-year period combining three typical crop rotations (using winter wheat, winter barley, sugar beet and maize) with three tillage scenarios (conventional tillage, reduced tillage and reduced tillage in combination with additional crop residues). The results showed that including soil erosion by water in the simulations led to a general decrease in SOC stocks relative to a baseline scenario (where no erosion took place). The SOC lost from these arable soils was mainly exported to adjacent sites and to the river system by lateral fluxes, with magnitudes differing between crop rotations and in all cases lower under conservation tillage practices than under conventional tillage. Although tillage erosion plays an important role in carbon redistribution within fields, lateral fluxes induced by water erosion led to a higher spatial and in-depth heterogeneity of SOC stocks with potential effects on the soil water holding capacity and crop yields. This indicates that studies assessing the effect of agricultural management practices on SOC stocks and other soil properties over the landscape should

  20. Fecal contamination of agricultural soils before and after hurricane-associated flooding in North Carolina.

    PubMed

    Casteel, Michael J; Sobsey, Mark D; Mueller, J Paul

    2006-01-01

    Hurricane Floyd and other storms in 1999 caused widespread and extensive flooding of eastern North Carolina and environmental contamination with fecal wastes from municipal wastewater and livestock operations. Because wastewater contains high levels of pathogenic micro-organisms, principal health risks to humans from flooding are consumption of crops grown in fecally contaminated soil and ingestion of contaminated water. Flood waters polluted with microbial and other contaminants also may be detrimental to the health of livestock and plant crops. In the present study, agricultural soils impacted by flood waters were analyzed for bacterial and viral indicators of fecal contamination. Total coliforms, fecal coliforms, Escherichia coli, spores of Clostridium perfringens, and both male specific (F+) and somatic coliphages were recovered from soil and assayed in liquid culture media. A number of samples were positive for the presence of fecal coliforms, E. coli, and coliphages, indicating the presence of human or animal feces. Most samples were positive for total coliforms, and almost all samples contained high levels of Cl. perfringens spores. The levels of Cl. perfringens spores were significantly (P < 0.001) higher in flooded soil (post-Hurricane Floyd) compared to pre-flood soil. Persistent fecal contamination of soil, as demonstrated by the high levels of Cl. perfringens spores, suggests the need for additional or alternative measures to protect crop-growing areas, including prospective microbiological monitoring and improved protection of watersheds from incidents capable of releasing fecal material. PMID:16423723

  1. Compressive response of some agricultural soils influenced by the mineralogy and moisture

    NASA Astrophysics Data System (ADS)

    Ajayi, A. E.; Dias Junior, M. S.; Curi, N.; Oladipo, I.

    2013-09-01

    This study aimed to investigate the mineralogy, moisture retention, and the compressive response of two agricultural soils from South West Nigeria. Undisturbed soil cores at the A and B horizons were collected and used in chemical and hydrophysical characterization and confined compression test. X-ray diffractograms of oriented fine clay fractions were also obtained. Our results indicate the prevalence of kaolinite minerals relating to the weathering process in these tropical soils. Moisture retention by the core samples was typically low with pre-compression stress values ranging from50 to 300 kPa at both sites. Analyses of the shape of the compression curves highlight the influence of soil moisture in shifts from the bi-linear to S-shaped models. Statistical homogeneity test of the load bearing capacity parameters showed that the soil mineralogy influences the response to loading by these soils. These observations provide a physical basis for the previous classification series of the soils in the studied area. We showed that the internal strength attributes of the soil could be inferred from the mineralogical properties and stress history. This could assist in decisions on sustainable mechanization in a datapoor environment.

  2. Measurement of nitrogen oxide emissions from an agricultural soil with a dynamic chamber system

    NASA Astrophysics Data System (ADS)

    Roelle, Paul; Aneja, Viney P.; O'Connor, J.; Robarge, W.; Kim, Deug-Soo; Levine, Joel S.

    1999-01-01

    Biogenic soil emissions of nitric oxide (NO) were measured from an intensively managed agricultural row crop (corn, Zea mays) during a 4 week period (May 15 through June 9, 1995). The site was located in Washington County, near the town of Plymouth, which is in the Lower Coastal Plain of North Carolina. Soil NO flux was determined using a dynamic flowthrough chamber technique. The measurement period was characterized by two distinguishing features: an application of nitrogen (N) fertilizer at the midpoint of the experiment and a nontypical rainfall pattern. Average NO flux prior to the application of N fertilizer was 31.5 ± 10.1 ng N m-2 s-1, and more than doubled (77.7 ± 63.7 ng N m-2 s-1) after the application of a side-dressing of N fertilizer. Average soil extractable nitrogen values did not change significantly following application of the side-dressing of N fertilizer. We attribute this failure to detect a significant difference in soil extractable nitrogen following N fertilization to the method in which the fertilizer was applied, the subsequent rainfall pattern, and the technique of soil sampling. NO flux followed the same diurnal trend as soil temperature, with maximum NO emissions coinciding with maximum soil temperature, and minimum NO emissions coinciding with minimum soil temperature. NO flux was found to increase exponentially with soil temperature, but only after fertilization. Due to subsurface irrigation practices employed by the farmer, changes in soil water content were minimal, and no relation could be drawn between soil water content and NO flux. Simultaneous measurements of NOy, NO2, and NO emissions revealed that NO and NO2 emissions represent 86 and 8.7%, respectively, of NOy emissions leaving the soil. Simultaneous NO flux measurements made by a closed box flux technique, at the same site, revealed no statistically significant differences between the two different methodologies for measuring NO flux.

  3. Scaling preferential flow processes in agricultural soils affected by tillage and trafficking at the field scale

    NASA Astrophysics Data System (ADS)

    Filipović, Vilim; Coquet, Yves

    2016-04-01

    There is an accumulation of experimental evidences that agricultural soils, at least the top horizons affected by tillage practices, are not homogeneous and present a structure that is strongly dependent on farming practices like tillage and trafficking. Soil tillage and trafficking can create compacted zones in the soil with hydraulic properties and porosity which are different from those of the non-compacted zones. This spatial variability can strongly influence transport processes and initiate preferential flow. Two or three dimensional models can be used to account for spatial variability created by agricultural practices, but such models need a detailed assessment of spatial heterogeneity which can be rather impractical to provide. This logically raises the question whether and how one dimensional model may be designed and used to account for the within-field spatial variability in soil structure created by agricultural practices. Preferential flow (dual-permeability) modelling performed with HYDRUS-1D will be confronted to classical modelling based on the Richards and convection-dispersion equations using HYDRUS-2D taking into account the various soil heterogeneities created by agricultural practices. Our goal is to derive one set of equivalent 1D soil hydraulic parameters from 2D simulations which accounts for soil heterogeneities created by agricultural operations. A field experiment was carried out in two phases: infiltration and redistribution on a plot by uniform sprinkle irrigation with water or bromide solution. Prior to the field experiment the soil structure of the tilled layer was determined along the face of a large trench perpendicular to the tillage direction (0.7 m depth and 3.1 m wide). Thirty TDR probes and tensiometers were installed in different soil structural zones (Δ compacted soil and Γ macroporous soil) which ensured soil water monitoring throughout the experiment. A map of bromide was constructed from small core samples (4 cm diam

  4. Role of carbonates in soil organic matter stabilization in agricultural Mediterranean soils

    NASA Astrophysics Data System (ADS)

    Apesteguía, Marcos; Virto, Iñigo; Plante, Alain

    2016-04-01

    Carbonated soils are present in many semiarid areas, where lithogenic and secondary carbonates are important constituents of the soil mineral matrix. The presence of CaCO3 in calcareous soils has been described as an organic matter stabilization agent mainly due to chemical stabilization mechanisms. In two recent studies in the north of Spain the importance of CaCO3 on soil physical characteristics was highlighted, as they were observed to be acting as macroaggregates stabilization agents. A third study was carried out on the same experimental site, with the hypothesis that the observed differences in aggregation may favor organic matter stabilization in carbonate-containing soils. With that aim we studied the soil physical characteristics (water retention and porosity) and the bioavailability of soil organic matter (SOM) in the two contrasting soils in that site, one Typic Calcixerept (CALC) and one Calcic Haploxerept (DECALC). Bioavailability was evaluated trough the measurement of mineralization rates in a 30 days soil incubations. Intact and disaggregated samples were incubated to evaluate the effect of physical protection on SOM bioavailability in whole soil and macroaggregates 2-5 mm samples. Therefore, four fractions of each soil were studied: intact whole soil < 5 mm (I-WS), disaggregated whole soil (D-WS), intact macroaggregates 2-5 mm (I-Magg), and disaggregated macroaggregates (D-Magg). Soil organic carbon content was greater in CALC and had smaller mineralization rates during incubation, indicating a smaller organic matter bioavailability for microbial decomposition. However, the greater increment of mineralization observed in DECALC after disaggregation, together with the scarce differences observed in physical characteristics among both soils, indicate that physical protection was not responsible of greater SOM stability in CALC soil. New hypotheses are needed to explain the observed better protection of organic matter in carbonate-rich Mediterranean

  5. DNA Damage in Vicia faba by Exposure to Agricultural Soils from Tlaxcala, Mexico.

    PubMed

    Juárez-Santacruz, L; García-Nieto, E; García-Gallegos, E; Romo-Gómez, C; Ortiz-Ortiz, E; Costilla-Salazar, R; Luna-Zendejas, H S

    2015-12-01

    The aim of this research was to quantify some POPs, such as p,p' DDT, p,p' DDE, and PCBs in agricultural soils of Tlaxcala, Mexico and evaluate their capacity for eliciting DNA damage, using Vicia faba as bioindicator. The values of ΣDDTs and ΣPCBs ranged from 8-24 to 118-26,983 µg/kg, respectively. The samples T1 (HQ = 9.3) and T2 (HQ = 53.9) showed concentrations of ΣPCBs higher than Canadian guidelines (SQGE = 500 µg/kg). The genotoxicity testing produced percentages of DNA fragmentation higher than negative control and statistically significant (p < 0.05), both in agricultural soils and organic extracts. The soils T2, T3, N4, and N5 showed a DICA from 2.6 to 3.1 times, statistically higher (p < 0.05) than negative control. In general, the agricultural soils have greater genotoxic capacity than the organic extracts, suggesting a potential risk to biota that depends upon this ecosystem. PMID:26385693

  6. DNA Damage in Vicia faba by Exposure to Agricultural Soils from Tlaxcala, Mexico.

    PubMed

    Juárez-Santacruz, L; García-Nieto, E; García-Gallegos, E; Romo-Gómez, C; Ortiz-Ortiz, E; Costilla-Salazar, R; Luna-Zendejas, H S

    2015-12-01

    The aim of this research was to quantify some POPs, such as p,p' DDT, p,p' DDE, and PCBs in agricultural soils of Tlaxcala, Mexico and evaluate their capacity for eliciting DNA damage, using Vicia faba as bioindicator. The values of ΣDDTs and ΣPCBs ranged from 8-24 to 118-26,983 µg/kg, respectively. The samples T1 (HQ = 9.3) and T2 (HQ = 53.9) showed concentrations of ΣPCBs higher than Canadian guidelines (SQGE = 500 µg/kg). The genotoxicity testing produced percentages of DNA fragmentation higher than negative control and statistically significant (p < 0.05), both in agricultural soils and organic extracts. The soils T2, T3, N4, and N5 showed a DICA from 2.6 to 3.1 times, statistically higher (p < 0.05) than negative control. In general, the agricultural soils have greater genotoxic capacity than the organic extracts, suggesting a potential risk to biota that depends upon this ecosystem.

  7. Magnetic properties of agricultural soil in the Pearl River Delta, South China - Spatial distribution and influencing factor analysis

    NASA Astrophysics Data System (ADS)

    Bian, Yong; Ouyang, Tingping; Zhu, Zhaoyu; Huang, Ningsheng; Wan, Hongfu; Li, Mingkun

    2014-08-01

    Environmental magnetism has been widely applied to soil science due to its speediness, non-destructiveness and cost-effectiveness. However, the magnetic investigation of agricultural soil, so closely related to human activity, is limited, most probably because of its complexity. Here we present a magnetic investigation of 301 agricultural soil samples collected from the Pearl River Delta (PRD, 112°E-115°E and 22°N-24°N), China. The results showed that both low and high coercivity magnetic minerals coexist in agricultural soil. The values of concentration-dependent parameters, low-field susceptibility (χlf), anhysteretic remanence magnetization susceptibility (χARM), and saturation isothermal remanence magnetization (SIRM) were much higher in the PRD plain than in the surrounding areas. The S-ratio (S- 300) showed a similar spatial pattern to the aforementioned parameters. By contrast, frequency-dependent susceptibility (χfd%) and χARM/SIRM were higher in the surrounding hilly and mountainous areas than in the PRD plain. Natural and anthropogenic factors such as parent material, soil type and cultivation methods play important roles in determining agricultural soil magnetic properties. Magnetic minerals were coarser grained and overall indicated higher concentrations in soils from river alluvium and deposited materials. Soils which had suffered long-term water submergence have the lowest magnetic mineral concentration, a result consistent with previous studies. The magnetic properties of agricultural soils are strongly influenced by cultivation methods. Other human activities, such as industrial development and concomitant emitted pollutants, might have had an additional impact on the magnetic properties of agricultural soil.

  8. Biochar has no effect on soil respiration across Chinese agricultural soils.

    PubMed

    Liu, Xiaoyu; Zheng, Jufeng; Zhang, Dengxiao; Cheng, Kun; Zhou, Huimin; Zhang, Afeng; Li, Lianqing; Joseph, Stephen; Smith, Pete; Crowley, David; Kuzyakov, Yakov; Pan, Genxing

    2016-06-01

    Biochar addition to soil has been widely accepted as an option to enhance soil carbon sequestration by introducing recalcitrant organic matter. However, it remains unclear whether biochar will negate the net carbon accumulation by increasing carbon loss through CO2 efflux from soil (soil respiration). The objectives of this study were to address: 1) whether biochar addition increases soil respiration; and whether biochar application rate and biochar type (feedstock and pyrolyzing system) affect soil respiration. Two series of field experiments were carried out at 8 sites representing the main crop production areas in China. In experiment 1, a single type of wheat straw biochar was amended at rates of 0, 20 and 40 tha(-1) in four rice paddies and three dry croplands. In experiment 2, four types of biochar (varying in feedstock and pyrolyzing system) were amended at rates of 0 and 20 tha(-1) in a rice paddy under rice-wheat rotation. Results showed that biochar addition had no effect on CO2 efflux from soils consistently across sites, although it increased topsoil organic carbon stock by 38% on average. Meanwhile, CO2 efflux from soils amended with 40 t of biochar did not significantly higher than soils amended with 20 t of biochar. While the biochars used in Experiment 2 had different carbon pools and physico-chemical properties, they had no effect on soil CO2 efflux. The soil CO2 efflux following biochar addition could be hardly explained by the changes in soil physic-chemical properties and in soil microbial biomass. Thus, we argue that biochar will not negate the net carbon accumulation by increasing carbon loss through CO2 efflux in agricultural soils. PMID:26950640

  9. Biochar has no effect on soil respiration across Chinese agricultural soils.

    PubMed

    Liu, Xiaoyu; Zheng, Jufeng; Zhang, Dengxiao; Cheng, Kun; Zhou, Huimin; Zhang, Afeng; Li, Lianqing; Joseph, Stephen; Smith, Pete; Crowley, David; Kuzyakov, Yakov; Pan, Genxing

    2016-06-01

    Biochar addition to soil has been widely accepted as an option to enhance soil carbon sequestration by introducing recalcitrant organic matter. However, it remains unclear whether biochar will negate the net carbon accumulation by increasing carbon loss through CO2 efflux from soil (soil respiration). The objectives of this study were to address: 1) whether biochar addition increases soil respiration; and whether biochar application rate and biochar type (feedstock and pyrolyzing system) affect soil respiration. Two series of field experiments were carried out at 8 sites representing the main crop production areas in China. In experiment 1, a single type of wheat straw biochar was amended at rates of 0, 20 and 40 tha(-1) in four rice paddies and three dry croplands. In experiment 2, four types of biochar (varying in feedstock and pyrolyzing system) were amended at rates of 0 and 20 tha(-1) in a rice paddy under rice-wheat rotation. Results showed that biochar addition had no effect on CO2 efflux from soils consistently across sites, although it increased topsoil organic carbon stock by 38% on average. Meanwhile, CO2 efflux from soils amended with 40 t of biochar did not significantly higher than soils amended with 20 t of biochar. While the biochars used in Experiment 2 had different carbon pools and physico-chemical properties, they had no effect on soil CO2 efflux. The soil CO2 efflux following biochar addition could be hardly explained by the changes in soil physic-chemical properties and in soil microbial biomass. Thus, we argue that biochar will not negate the net carbon accumulation by increasing carbon loss through CO2 efflux in agricultural soils.

  10. Nematode Communities in Organically and Conventionally Managed Agricultural Soils

    PubMed Central

    Neher, Deborah A.

    1999-01-01

    Interpretation of nematode community indices requires a reference to a relatively undisturbed community. Maturity and trophic diversity index values were compared for five pairs of certified organically and conventionally managed soils in the Piedmont region of North Carolina. Available nitrogen (nitrate, ammonium) was estimated at various lag periods relative to times of sampling for nematode communities to determine the strength of correlative relationship between nematode communities and nitrogen availability. Soils were sampled six times yearly in 1993 and 1994 to determine the best time of year to sample. Maturity values for plant parasites were greater in organically than conventionally managed soils, and differences between management systems were greater in fall than spring months. However, other maturity and diversity indices did not differ between the two management practices. Differences in crop species grown in the two systems accounted for most differences observed in the community of plant-parasitic nematodes. Indices of free-living nematodes were correlated negatively with concentrations of ammonium, whereas indices of plant-parasitic nematodes were correlated positively with concentrations of nitrate. Due to the similarity of index values between the two systems, organically managed soils are not suitable reference sites for monitoring and assessing the biological aspects of soil quality for annually harvested crops. PMID:19270884

  11. Soil CO2 emissions in terms of irrigation management in an agricultural soil

    NASA Astrophysics Data System (ADS)

    Zornoza, Raúl; Acosta, José A.; María de la Rosa, José; Faz, Ángel; Domingo, Rafael; Pérez-Pastor, Alejandro; Ángeles Muñoz, María

    2014-05-01

    Irrigation water restrictions in the Mediterranean area are reaching worrying proportions and represent a serious threat to traditional crops and encourage the movement of people who choose to work in other activities. This situation has created a growing interest in water conservation, particularly among practitioners of irrigated agriculture, the main recipient of water resources (>80%). For these and other reasons, the scientific and technical irrigation scheduling of water use to maintain and even improve harvest yield and quality has been and will remain a major challenge for irrigated agriculture. Apart from environmental and economic benefits by water savings, deficit irrigation may contribute to reduce soil CO2 emissions and enhance C sequestration in soils. The reduction of soil moisture levels decreases microbial activity, with the resulting slowing down of organic matter mineralization. Besides, the application of water by irrigation may increment the precipitation rate of carbonates, favoring the storage of C, but depending on the source of calcium or bicarbonate, the net reaction can be either storage or release of C. Thus, the objective of this study was to assess if deficit irrigation, besides contributing to water savings, can reduce soil CO2 emissions and favor the accumulation of C in soils in stable forms. The experiment was carried out along 2012 in a commercial orchard from southeast Spain cultivated with nectarine trees (Prunus persica cv. 'Viowhite'). The irrigation system was drip localized. Three irrigation treatments were assayed: a control (CT), irrigated to satisfy the total hydric needs of the crop; a first deficit irrigation (DI1), irrigated as CT except for postharvest period (16 June - 28 October) were 50% of CT was applied; and a second deficit irrigation (DI2), irrigated as DI1, except for two periods in which irrigation was suppressed (16 June-6 July and 21 July-17 August). Each treatment was setup in triplicate, randomly

  12. Modelling agricultural suitability along soil transects under current conditions and improved scenario of soil factors

    NASA Astrophysics Data System (ADS)

    Abd-Elmabod, Sameh K.; Jordán, Antonio; Fleskens, Luuk; van der Ploeg, Martine; Muñoz-Rojas, Miriam; Anaya-Romero, María; van der Salm, Renée J.; De la Rosa, Diego

    2015-04-01

    Agricultural land suitability analysis and improvement of soils by addressing major limitations may be a strategy for climate change adaptation. This study aims to investigate the influence of topography and variability of soil factors on the suitability of 12 annual, semiannual and perennial Mediterranean crops in the province of Seville (southern Spain). In order to represent the variability in elevation, lithology and soil, two latitudinal and longitudinal (S-N and W-E) soil transects (TA and TB) were considered including 63 representative points at regular 4 km intervals. These points were represented by 41 soil profiles from the SDBm soil database -Seville. Almagra model, a component of the agro-ecological decision support system MicroLEIS, was used to assess soil suitability. Results were grouped into five soil suitability classes: S1-optimum, S2-high, S3-moderate, S4-marginal and S5-not suitable. Each class was divided in subclasses according to the main soil limiting factors: depth (p), texture (t), drainage (d), carbonate content (c), salinity (s), sodium saturation (a), and the degree of development of the soil profile (g). This research also aimed to maximize soil potential by improving limiting factors d, c, s and a after soil restoration. Therefore, management techniques were also considered as possible scenarios in this study. The results of the evaluation showed that soil suitability ranged between S1 and S5p - S5s along of the transects. In the northern extreme of transect TA, high content of gravels and coarse texture are limiting factors (soils are classified as S4t) In contrast, the limiting factor in the eastern extreme of transect TB is the shallow useful depth (S5p subclass). The absence of calcium carbonate becomes a limiting factor in some parts of TA. In contrast, the excessive content of calcium carbonate appeared to be a limiting factor for crops in some intermediate points of TB transect. For both transects, soil salinity is the main

  13. A contemporary decennial global Landsat sample of changing agricultural field sizes

    NASA Astrophysics Data System (ADS)

    White, Emma; Roy, David

    2014-05-01

    Agriculture has caused significant human induced Land Cover Land Use (LCLU) change, with dramatic cropland expansion in the last century and significant increases in productivity over the past few decades. Satellite data have been used for agricultural applications including cropland distribution mapping, crop condition monitoring, crop production assessment and yield prediction. Satellite based agricultural applications are less reliable when the sensor spatial resolution is small relative to the field size. However, to date, studies of agricultural field size distributions and their change have been limited, even though this information is needed to inform the design of agricultural satellite monitoring systems. Moreover, the size of agricultural fields is a fundamental description of rural landscapes and provides an insight into the drivers of rural LCLU change. In many parts of the world field sizes may have increased. Increasing field sizes cause a subsequent decrease in the number of fields and therefore decreased landscape spatial complexity with impacts on biodiversity, habitat, soil erosion, plant-pollinator interactions, and impacts on the diffusion of herbicides, pesticides, disease pathogens, and pests. The Landsat series of satellites provide the longest record of global land observations, with 30m observations available since 1982. Landsat data are used to examine contemporary field size changes in a period (1980 to 2010) when significant global agricultural changes have occurred. A multi-scale sampling approach is used to locate global hotspots of field size change by examination of a recent global agricultural yield map and literature review. Nine hotspots are selected where significant field size change is apparent and where change has been driven by technological advancements (Argentina and U.S.), abrupt societal changes (Albania and Zimbabwe), government land use and agricultural policy changes (China, Malaysia, Brazil), and/or constrained by

  14. GEMAS: Geochemical Mapping of the agricultural and grasing land soils of Europe

    NASA Astrophysics Data System (ADS)

    Reimann, Clemens; Birke, Manfred; Demetriades, Alecos; Filzmoser, Peter; O'Connor, Patrick

    2014-05-01

    Geochemical Mapping of Agricultural and grazing land Soil (GEMAS) is a cooperative project between the Geochemistry Expert Group of EuroGeoSurveys and Eurometaux. During 2008 and until early 2009, a total of 2108 samples of agricultural (ploughed land, 0-20 cm, Ap-samples) and 2023 samples of grazing land (0-10 cm, Gr samples) soil were collected at a density of 1 site/2500 km2 each from 33 European countries, covering an area of 5,600,000 km2. All samples were analysed for 52 chemical elements following an aqua regia extraction, 41 elements by XRF (total), and soil properties, like CEC, TOC, pH (CaCl2), following tight external quality control procedures. In addition, the Ap soil samples were analysed for 57 elements in a mobile metal ion (MMI®) extraction, Pb isotopes and magnetic susceptibility. The results demonstrate that robust geochemical maps of Europe can be constructed based on low density sampling. The two independent sample materials, Ap and Gr, show very comparable distribution patterns across Europe. At the European scale, element distribution patterns are governed by natural processes, most often a combination of geology and climate. The geochemical maps reflect most of the known metal mining districts in Europe. In addition, a number of new anomalies emerge that may indicate mineral potential. The size of some anomalies is such that they can only be detected when mapping at the continental scale. For some elements completely new geological settings are detected. An anthropogenic impact at a much more local scale is discernible in the immediate vicinity of some major European cities (e.g., London, Paris) and some metal smelters. The impact of agriculture is visible for Cu (vineyard soil) and for some additional elements only in the mobile metal ion (MMI®) extraction. For several trace elements, deficiency issues are a larger threat to plant, animal, and finally human health at the European scale than toxicity. Taking the famous step back to see the

  15. Acid precipitation impacts on agricultural soil management practices

    SciTech Connect

    Moskowitz, P.D.; Medeiros, W.H.; Coveney, E.A.; Lewin, K.F.; Rosenthal, R.E.

    1986-02-01

    Acid precipitation can have positive (reduced nitrogen fertilizer requirements) and negative (increased need to neutralize soil acidity) impacts on agricultural soil management practices. This paper compares the total annual deposition of nitrogen in acid precipitation with farmer applied fertilizer use and with nitrogen uptake for major crops. It also estimates the amount of lime needed to neutralize soil acidity originating from wet H/sup +/ deposition. First-order estimates indicate that the quantity of nitrogen annually deposited in the eastern US by wet acid deposition on croplands is 6% of the amount applied as fertilizer. Nitrogen deposited as wet deposition may be relatively important to unmanaged nonleguminous crops (e.g., hay) which are grown over extensive land areas. Soil acidity, which can be increased by natural (e.g., nitrogen fixation) and anthropogenic mechanisms (e.g., fertilizer application, acidic deposition) is often neutralized by the application of lime. Estimates indicate that in the eastern US, approx.2% of applied lime is used to neutralize acidity caused by wet acid deposition.

  16. Environmental Filtering of Microbial Communities in Agricultural Soil Shifts with Crop Growth.

    PubMed

    Hargreaves, Sarah K; Williams, Ryan J; Hofmockel, Kirsten S

    2015-01-01

    Plant and soil properties cooperatively structure soil microbial communities, with implications for ecosystem functioning. However, the extent to which each factor contributes to community structuring is not fully understood. To quantify the influence of plants and soil properties on microbial diversity and composition in an agricultural context, we conducted an experiment within a corn-based annual cropping system and a perennial switchgrass cropping system across three topographic positions. We sequenced barcoded 16S ribosomal RNA genes from whole soil three times throughout a single growing season and across two years in July. To target the belowground effects of plants, we also sampled rhizosphere soil in July. We hypothesized that microbial community α-diversity and composition (β-diversity) would be more sensitive to cropping system effects (annual vs. perennial inputs) than edaphic differences among topographic positions, with greater differences occurring in the rhizosphere compared to whole soil. We found that microbial community composition consistently varied with topographic position, and cropping system and the rhizosphere influenced α-diversity. In July, cropping system and rhizosphere structured a small but specific group of microbes implying a subset of microbial taxa, rather than broad shifts in community composition, may explain previously observed differences in resource cycling between treatments. Using rank abundance analysis, we detected enrichment of Saprospirales and Actinomycetales, including cellulose and chitin degraders, in the rhizosphere soil and enrichment of Nitrospirales, Syntrophobacterales, and MND1 in the whole soil. Overall, these findings support environmental filtering for the soil microbial community first by soil and second by the rhizosphere. Across cropping systems, plants selected for a general rhizosphere community with evidence for plant-specific effects related to time of sampling.

  17. Distribution of selenium in soils of agricultural fields, western San Joaquin Valley, California

    USGS Publications Warehouse

    Fujii, Roger; Deverel, S.J.; Hatfield, D.B.

    1987-01-01

    Soils from three agricultural fields in the western San Joaquin Valley were analyzed for soluble, adsorbed, and total concentrations of selenium (Se) to assess the distribution and forms of Se, and the relation of the distribution and forms of Se to the leaching of Se from soils. Soil samples were collected in three fields with drainage systems of different ages (6, 15, 1.5 yr) and different Se concentrations in drain water (58, 430, 3700 micrograms/L respectively). Preliminary methods to determine total Se and estimate adsorbed Se were developed. Of the three fields, concentrations of soluble Se and salinity were highest in soils from the field drained for 1.5 yr and lowest in the field drained for 6 yr. The field drained for 1.5 yr also had the highest concentration of total Se in soil; a median of 1.2 microgram/gm. Of the total concentration of Se in soil from all three fields, the proportion of adsorbed Se and soluble Se ranged from 1 to 11% and < 1 to 63%, respectively. Most of the variance in soluble Se is explained by salinity ( r sq > 0.68) in saturation extracts of soils sampled from below the water table, reflecting evaporative concentration of Se and salinity. In contrast, most soluble salts and Se apparently have been leached from the unsaturated soils in the fields drained for 6 and 15 yr; therefore, the correlation was lower between Se and salinity in saturation extracts of those soils (r sq < 0.33). Among soils from all three fields, the ratio of Se to salinity in saturation extracts increased with increasing salinity. (Author 's abstract)

  18. Soil phosphorus mobilization in the rhizosphere of cover crops has little effect on phosphorus cycling in California agricultural soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    External phosphorus (P) inputs to agricultural soils are needed to replace soil P removed by harvest and maintain soil fertility. Alternative fertilization approaches that maintain soil fertility while reducing P inputs could improve current practices that often result in excessive P application and...

  19. Effects of soil properties on the transfer of cadmium from soil to wheat in the Yangtze River delta region, China--a typical industry-agriculture transition area.

    PubMed

    Wang, Cheng; Ji, Junfeng; Yang, Zhongfang; Chen, Lingxiao; Browne, Patrick; Yu, Ruilian

    2012-08-01

    In order to identify the effects of soil properties on the transfer of Cd from soil to wheat under actual field conditions, 126 pairs of topsoil and wheat samples were collected from the Yangtze River delta region, China. Relevant parameters (Cd, Ca, Mg, Fe, Mn, Zn, N, P, K, S, pH, total organic carbon, and speciation of soil Cd) in soil and wheat tissues were analyzed, and the results were treated by statistical methods. Soil samples (19.8%) and 14.3% of the wheat grain samples exceeded the relevant maximum permissible Cd concentrations in China for agricultural soil and wheat grain, respectively. The major speciations of Cd in soil were exchangeable, bound to carbonates and fulvic and humic acid fraction, and they were readily affected by soil pH, total Ca, Mg, S and P, DTPA-Fe, Ex-Ca, and Ex-Mg. Cadmium showed a strong correlation with Fe, S, and P present in the grain and the soil, whereas there was no significant correlation in the straw or root. Generally, soil pH, Ca, Mg, Mn, P, and slowly available K restricted Cd transfer from soil to wheat, whereas soil S, N, Zn, DTPA-Fe, and total organic carbon enhance Cd uptake by wheat.

  20. Future trends in soil cadmium concentration under current cadmium fluxes to European agricultural soils.

    PubMed

    Six, L; Smolders, E

    2014-07-01

    The gradual increase of soil cadmium concentrations in European soils during the 20th century has prompted environmental legislation to limit soil cadmium (Cd) accumulation. Mass balances (input-output) reflecting the period 1980-1995 predicted larger Cd inputs via phosphate (P) fertilizers and atmospheric deposition than outputs via crop uptake and leaching. This study updates the Cd mass balance for the agricultural top soils of EU-27+Norway (EU-27+1). Over the past 15 years, the use of P fertilizers in the EU-27+1 has decreased by 40%. The current mean atmospheric deposition of Cd in EU is 0.35 g Cd ha(-1) yr(-1), this is strikingly smaller than values used in the previous EU mass balances (~3 g Cd ha(-1) yr(-1)). Leaching of Cd was estimated with most recent data of soil solution Cd concentrations in 151 soils, which cover the range of European soil properties. No significant time trends were found in the data of net applications of Cd via manure, compost, sludge and lime, all being small sources of Cd at a large scale. Modelling of the future long-term changes in soil Cd concentrations in agricultural top soils under cereal or potato culture predicts soil Cd concentrations to decrease by 15% over the next 100 years in an average scenario, with decreasing trends in some scenarios being more prevalent than increasing trends in other scenarios. These Cd balances have reverted from the general positive balances estimated 10 or more years ago. Uncertainty analysis suggests that leaching is the most uncertain relative to other fluxes.

  1. Kinetics of aerobic and anaerobic biomineralization of atrazine in surface and subsurface agricultural soils in Ohio.

    PubMed

    Tuovinen, Olli H; Deshmukh, Vaidehi; Özkaya, Bestamin; Radosevich, Mark

    2015-01-01

    The purpose of this study was to assess atrazine mineralization in surface and subsurface samples retrieved from vertical cores of agricultural soils from two farm sites in Ohio. The Defiance site (NW-Ohio) was on soybean-corn rotation and Piketon (S-Ohio) was on continuous corn cultivation. Both sites had a history of atrazine application for at least a couple of decades. The clay fraction increased at the Defiance site and the organic matter and total N content decreased with depth at both sites. Mineralization of atrazine was assessed by measurement of (14)CO2 during incubation of soil samples with [U-ring-(14)C]-atrazine. Abiotic mineralization was negligible in all soil samples. Aerobic mineralization rate constants declined and the corresponding half-lives increased with depth at the Defiance site. Anaerobic mineralization (supplemented with nitrate) was mostly below the detection at the Defiance site. In Piketon samples, the kinetic parameters of aerobic and anaerobic biomineralization of atrazine displayed considerable scatter among replicate cores and duplicate biometers. In general, this study concludes that data especially for anaerobic biomineralization of atrazine can be more variable as compared to aerobic conditions and cannot be extrapolated from one agricultural site to another. PMID:26273756

  2. Kinetics of aerobic and anaerobic biomineralization of atrazine in surface and subsurface agricultural soils in Ohio.

    PubMed

    Tuovinen, Olli H; Deshmukh, Vaidehi; Özkaya, Bestamin; Radosevich, Mark

    2015-01-01

    The purpose of this study was to assess atrazine mineralization in surface and subsurface samples retrieved from vertical cores of agricultural soils from two farm sites in Ohio. The Defiance site (NW-Ohio) was on soybean-corn rotation and Piketon (S-Ohio) was on continuous corn cultivation. Both sites had a history of atrazine application for at least a couple of decades. The clay fraction increased at the Defiance site and the organic matter and total N content decreased with depth at both sites. Mineralization of atrazine was assessed by measurement of (14)CO2 during incubation of soil samples with [U-ring-(14)C]-atrazine. Abiotic mineralization was negligible in all soil samples. Aerobic mineralization rate constants declined and the corresponding half-lives increased with depth at the Defiance site. Anaerobic mineralization (supplemented with nitrate) was mostly below the detection at the Defiance site. In Piketon samples, the kinetic parameters of aerobic and anaerobic biomineralization of atrazine displayed considerable scatter among replicate cores and duplicate biometers. In general, this study concludes that data especially for anaerobic biomineralization of atrazine can be more variable as compared to aerobic conditions and cannot be extrapolated from one agricultural site to another.

  3. Effects of biochar and elevated soil temperature on soil microbial activity and abundance in an agricultural system

    NASA Astrophysics Data System (ADS)

    Bamminger, Chris; Poll, Christian; Marhan, Sven

    2014-05-01

    As a consequence of Global Warming, rising surface temperatures will likely cause increased soil temperatures. Soil warming has already been shown to, at least temporarily, increase microbial activity and, therefore, the emissions of greenhouse gases like CO2 and N2O. This underlines the need for methods to stabilize soil organic matter and to prevent further boost of the greenhouse gas effect. Plant-derived biochar as a soil amendment could be a valuable tool to capture CO2 from the atmosphere and sequestrate it in soil on the long-term. During the process of pyrolysis, plant biomass is heated in an oxygen-low atmosphere producing the highly stable solid matter biochar. Biochar is generally stable against microbial degradation due to its chemical structure and it, therefore, persists in soil for long periods. Previous experiments indicated that biochar improves or changes several physical or chemical soil traits such as water holding capacity, cation exchange capacity or soil structure, but also biotic properties like microbial activity/abundance, greenhouse gas emissions and plant growth. Changes in the soil microbial abundance and community composition alter their metabolism, but likely also affect plant productivity. The interaction of biochar addition and soil temperature increase on soil microbial properties and plant growth was yet not investigated on the field scale. To investigate whether warming could change biochar effects in soil, we conducted a field experiment attached to a soil warming experiment on an agricultural experimental site near the University of Hohenheim, already running since July 2008. The biochar field experiment was set up as two-factorial randomized block design (n=4) with the factors biochar amendment (0, 30 t ha-1) and soil temperature (ambient, elevated=ambient +2.5° C) starting from August 2013. Each plot has a dimension of 1x1m and is equipped with combined soil temperature and moisture sensors. Slow pyrolysis biochar from the C

  4. Sewage sludge, compost and other representative organic wastes as agricultural soil amendments: Benefits versus limiting factors.

    PubMed

    Alvarenga, Paula; Mourinha, Clarisse; Farto, Márcia; Santos, Teresa; Palma, Patrícia; Sengo, Joana; Morais, Marie-Christine; Cunha-Queda, Cristina

    2015-06-01

    Nine different samples of sewage sludges, composts and other representative organic wastes, with potential interest to be used as agricultural soil amendments, were characterized: municipal sewage sludge (SS1 and SS2), agro industrial sludge (AIS), municipal slaughterhouse sludge (MSS), mixed municipal solid waste compost (MMSWC), agricultural wastes compost (AWC), compost produced from agricultural wastes and sewage sludge (AWSSC), pig slurry digestate (PSD) and paper mill wastes (PMW). The characterization was made considering their: (i) physicochemical parameters, (ii) total and bioavailable heavy metals (Cd, Cr, Cu, Ni, Pb, Zn and Hg), (iii) organic contaminants, (iv) pathogenic microorganisms and (v) stability and phytotoxicity indicators. All the sludges, municipal or other, comply with the requirements of the legislation regarding the possibility of their application to agricultural soil (with the exception of SS2, due to its pathogenic microorganisms content), with a content of organic matter and nutrients that make them interesting to be applied to soil. The composts presented, in general, some constraints regarding their application to soil, and their impairment was due to the existence of heavy metal concentrations exceeding the proposed limit of the draft European legislation. As a consequence, with the exception of AWSSC, most compost samples were not able to meet these quality criteria, which are more conservative for compost than for sewage sludge. From the results, the composting of sewage sludge is recommended as a way to turn a less stabilized waste into a material that is no longer classified as a waste and, judging by the results of this work, with lower heavy metal content than the other composted materials, and without sanitation problems.

  5. Sewage sludge, compost and other representative organic wastes as agricultural soil amendments: Benefits versus limiting factors.

    PubMed

    Alvarenga, Paula; Mourinha, Clarisse; Farto, Márcia; Santos, Teresa; Palma, Patrícia; Sengo, Joana; Morais, Marie-Christine; Cunha-Queda, Cristina

    2015-06-01

    Nine different samples of sewage sludges, composts and other representative organic wastes, with potential interest to be used as agricultural soil amendments, were characterized: municipal sewage sludge (SS1 and SS2), agro industrial sludge (AIS), municipal slaughterhouse sludge (MSS), mixed municipal solid waste compost (MMSWC), agricultural wastes compost (AWC), compost produced from agricultural wastes and sewage sludge (AWSSC), pig slurry digestate (PSD) and paper mill wastes (PMW). The characterization was made considering their: (i) physicochemical parameters, (ii) total and bioavailable heavy metals (Cd, Cr, Cu, Ni, Pb, Zn and Hg), (iii) organic contaminants, (iv) pathogenic microorganisms and (v) stability and phytotoxicity indicators. All the sludges, municipal or other, comply with the requirements of the legislation regarding the possibility of their application to agricultural soil (with the exception of SS2, due to its pathogenic microorganisms content), with a content of organic matter and nutrients that make them interesting to be applied to soil. The composts presented, in general, some constraints regarding their application to soil, and their impairment was due to the existence of heavy metal concentrations exceeding the proposed limit of the draft European legislation. As a consequence, with the exception of AWSSC, most compost samples were not able to meet these quality criteria, which are more conservative for compost than for sewage sludge. From the results, the composting of sewage sludge is recommended as a way to turn a less stabilized waste into a material that is no longer classified as a waste and, judging by the results of this work, with lower heavy metal content than the other composted materials, and without sanitation problems. PMID:25708406

  6. Residues of endosulfan in surface and subsurface agricultural soil and its bioremediation.

    PubMed

    Odukkathil, Greeshma; Vasudevan, Namasivayam

    2016-01-01

    The persistence of many hydrophobic pesticides has been reported by various workers in various soil environments and its bioremediation is a major concern due to less bioavailability. In the present study, the pesticide residues in the surface and subsurface soil in an area of intense agricultural activity in Pakkam Village of Thiruvallur District, Tamilnadu, India, and its bioremediation using a novel bacterial consortium was investigated. Surface (0-15 cm) and subsurface soils (15-30 cm and 30-40 cm) were sampled, and pesticides in different layers of the soil were analyzed. Alpha endosulfan and beta endosulfan concentrations ranged from 1.42 to 3.4 mg/g and 1.28-3.1 mg/g in the surface soil, 0.6-1.4 mg/g and 0.3-0.6 mg/g in the subsurface soil (15-30 cm), and 0.9-1.5 mg/g and 0.34-1.3 mg/g in the subsurface soil (30-40 cm) respectively. Residues of other persistent pesticides were also detected in minor concentrations. These soil layers were subjected to bioremediation using a novel bacterial consortium under a simulated soil profile condition in a soil reactor. The complete removal of alpha and beta endosulfan was observed over 25 days. Residues of endosulfate were also detected during bioremediation, which was subsequently degraded on the 30th day. This study revealed the existence of endosulfan in the surface and subsurface soils and also proved that the removal of such a ubiquitous pesticide in the surface and subsurface environment can be achieved in the field by bioaugumenting a biosurfactant-producing bacterial consortium that degrades pesticides.

  7. Characterization of methanotrophic bacterial populations in natural and agricultural aerobic soils of the European Russia

    NASA Astrophysics Data System (ADS)

    Kravchenko, Irina; Sukhacheva, Marina; Kizilova, Anna

    2014-05-01

    Atmospheric methane contributes to about 20% of the total radiative forcing by long-lived greenhouse gases, and microbial methane oxidation in upland soils is the only biological sink of methane. Microbial methane oxidation in aerated upland soils is estimated as 15 - 45 Tg yr-1 or 3-9% of the annual sink. Therefore there is need of extensive research to characterize methanotrophic activity in various ecosystems for possible application to reduce atmospheric methane fluxes and to minimize global climate change. The vast majority of known aerobic methanotrophs belongs to the Proteobacteria and placed in the families Methylococcaceae in the Gammaproteobacteria, and Methylocystaceae and Beijerinckiaceae in the Alphaproteobacteria. Known exceptions include the phylum Verrucomicrobia and uncultured methanotrophs such as Candidatus 'Methylomirabilis oxyfera' affiliated with the 'NC10' phylum. Plenty of studies of aerobic methane oxidation and key players of the process have been performed on various types of soils, and it was found that Methylocystis spp and uncultivated methanotrophs are abundant in upland soils. Two of the uncultured groups are upland soil cluster alphaproteobacteria (USCa) and gammaproteobacteria (USCg), as revealed by cultivation-independent surveys of pmoA diversity. Russia is extremely rich in soil types due to its vast territories, and most of these soils have never been investigated from the aspect of methanotrophy. This study addresses methane oxidation activity and diversity of aerobic methanotrophic bacteria in eight types of natural aerobic soils, four of which also had been under agricultural use. Methane fluxes have been measured by in situ static chamber method and methane oxidation rates in soil samples - by radioisotope tracer (14CH4) technique. Changes in methanotroph diversity and abundance were assessed by cloning and Sanger sequencing, and quantitative real-time PCR of pmoA genes. Methanotrophic population of unmanaged soils turned

  8. Enhanced method for microbial community DNA extraction and purification from agricultural yellow loess soil.

    PubMed

    Kathiravan, Mathur Nadarajan; Gim, Geun Ho; Ryu, Jaewon; Kim, Pyung Il; Lee, Chul Won; Kim, Si Wouk

    2015-11-01

    In this study, novel DNA extraction and purification methods were developed to obtain high-quantity and reliable quality DNA from the microbial community of agricultural yellow loess soil samples. The efficiencies of five different soil DNAextraction protocols were evaluated on the basis of DNA yield, quality and DNA shearing. Our suggested extraction method, which used CTAB, EDTA and cell membrane lytic enzymes in the extraction followed by DNA precipitation using isopropanol, yielded a maximum DNA content of 42.28 ± 5.59 µg/g soil. In addition, among the five different purification protocols, the acid-treated polyvinyl polypyrrolidone (PVPP) spin column purification method yielded high-quality DNA and recovered 91% of DNA from the crude DNA. Spectrophotometry revealed that the ultraviolet A 260/A 230 and A 260/A 280 absorbance ratios of the purified DNA were 1.82 ± 0.03 and 1.94 ± 0.05, respectively. PCR-based 16S rRNA amplification showed clear bands at ~1.5 kb with acid-treated PVPP-purified DNA templates. In conclusion, our suggested extraction and purification protocols can be used to recover high concentration, high purity, and high-molecular-weight DNA from clay and silica-rich agricultural soil samples.

  9. Soil conservation under climate change: use of recovery biomasses on agricultural soil subjected to the passage of agricultural machinery

    NASA Astrophysics Data System (ADS)

    Bergonzoli, S.; Beni, C.; Servadio, P.

    2012-04-01

    Biomass administration is a good practice to preserve the soil fertility in climate change conditions. A test regarding the use of compost derived by wine distillation residues was conducted in the coastal area sited west of Rome, on a sandy soil in continuous cropping with carrot, two cycles per year, with a consequent deep environmental impact. The soil was fertilized with different systems: T = unfertilized soil; F = fertigation 200 kg N ha-1; FC = fertigation 100 kg N ha-1 plus half agronomic dose of compost 4 t ha-1; C2 = double compost dose 16 t ha-1; C4 = quadruple compost dose 32 t ha-1. The functional qualities of the soil, subjected to the passage of agricultural machineries, were determined through the following parameters: bulk density, shear strength, water infiltration rate, organic matter and nitrogen content, cation exchange capacity. At the summer harvest, yield of carrots, their sugar content, firmness and nutrients concentration were determined. The plots only amended (C2 and C4), compared to other treatments, presented lower bulk density (1.36 and 1.28 Mg m-3 respectively), higher shear strength (9 and 8 kPa respectively), as well as increased hydraulic conductivity. In these treatments (C2 and C4), in addition, occurred a higher content of organic matter (0.95 and 1.07% respectively) and nitrogen (0.11 and 0.12% respectively) and increased CEC (541 and 556 respectively) respect to the T treatment that was 521 meq 100g-1. In plots T and F, the organic matter content was reduced at the end of the field test. The yield of carrots increased in FC, C2, and C4, compared to the other treatments. In plots C4, however, morphological changes were induced in approximately 30% of tap-roots, due to the excessive compost dose. In treatments C2 and C4 was observed a reduction of the concentration of Na in the roots, as opposed to the higher concentration of Ca and K and trace elements. The administration of compost has also induced the increase of soluble

  10. Ecological Risk of Heavy Metals and a Metalloid in Agricultural Soils in Tarkwa, Ghana.

    PubMed

    Bortey-Sam, Nesta; Nakayama, Shouta M M; Akoto, Osei; Ikenaka, Yoshinori; Baidoo, Elvis; Mizukawa, Hazuki; Ishizuka, Mayumi

    2015-09-01

    Heavy metals and a metalloid in agricultural soils in 19 communities in Tarkwa were analyzed to assess the potential ecological risk. A total of 147 soil samples were collected in June, 2012 and analyzed for As, Cd, Co, Cr, Cu, Hg, Ni, Pb and Zn. Mean concentrations (mg/kg dw) of heavy metals in the communities decreased in order of Zn (39) ˃ Cr (21) ˃ Pb (7.2) ˃ Cu (6.2) ˃ As (4.4) ˃ Ni (3.7) ˃ Co (1.8) ˃ Hg (0.32) ˃ Cd (0.050). Correlations among heavy metals and soil properties indicated that soil organic matter could have substantial influence on the total contents of these metals in soil. From the results, integrated pollution (C(deg)) in some communities such as, Wangarakrom (11), Badukrom (13) and T-Tamso (17) indicated high pollution with toxic metals, especially from As and Hg. Potential ecological risk (RI) indices indicated low (Mile 7) to high risks (Wangarakrom; Badukrom) of metals. Based on pollution coefficient (C(i)(f)), C(deg), monomial ecological risk (E(i)(r)) and RI, the investigated soils fall within low to high contamination and risk of heavy metals to the ecological system especially plants, soil invertebrates and/or mammalian wildlife. This represented moderate potential ecological risk in the study area, and mining activities have played a significant role.

  11. Ecological Risk of Heavy Metals and a Metalloid in Agricultural Soils in Tarkwa, Ghana

    PubMed Central

    Bortey-Sam, Nesta; Nakayama, Shouta M. M.; Akoto, Osei; Ikenaka, Yoshinori; Baidoo, Elvis; Mizukawa, Hazuki; Ishizuka, Mayumi

    2015-01-01

    Heavy metals and a metalloid in agricultural soils in 19 communities in Tarkwa were analyzed to assess the potential ecological risk. A total of 147 soil samples were collected in June, 2012 and analyzed for As, Cd, Co, Cr, Cu, Hg, Ni, Pb and Zn. Mean concentrations (mg/kg dw) of heavy metals in the communities decreased in order of Zn (39) ˃ Cr (21) ˃ Pb (7.2) ˃ Cu (6.2) ˃ As (4.4) ˃ Ni (3.7) ˃ Co (1.8) ˃ Hg (0.32) ˃ Cd (0.050). Correlations among heavy metals and soil properties indicated that soil organic matter could have substantial influence on the total contents of these metals in soil. From the results, integrated pollution (Cdeg) in some communities such as, Wangarakrom (11), Badukrom (13) and T–Tamso (17) indicated high pollution with toxic metals, especially from As and Hg. Potential ecological risk (RI) indices indicated low (Mile 7) to high risks (Wangarakrom; Badukrom) of metals. Based on pollution coefficient (Cif), Cdeg, monomial ecological risk (Eir) and RI, the investigated soils fall within low to high contamination and risk of heavy metals to the ecological system especially plants, soil invertebrates and/or mammalian wildlife. This represented moderate potential ecological risk in the study area, and mining activities have played a significant role. PMID:26378563

  12. Distribution of soil organic carbon in two small agricultural Mediterranean catchments.

    NASA Astrophysics Data System (ADS)

    Gomez, J. A.; Burguet, M.; Taguas, M. E.; Perez, R.; Ayuso, J. L.; Vanwallgehem, T.; Giraldez, J. V.; Vanderlinden, K.

    2012-04-01

    Soil organic carbon (SOC) is a key indicator of soil quality and a major factor for evaluating carbon sequestration schemes in forest and agricultural soils. However, at the farm or catchment scale SOC presents a large spatial variability which complicates the evaluation of soil quality (Gomez et al., 2009) and the certification of the potential for carbon sequestration. We hypothesize that the typical row crop configuration of olive orchards, with cover crops or bare soil in-between the rows, can explain a vast proportion of this variability. However, it is also expected that agricultural activities and topography-driven erosion processes at different scales (Van Oost et al., 2007) will contribute to SOC variability. Given the complexity of this problem and the important experimental effort required to resolve it, there are to our knowledge relatively few studies that have addressed this issue, especially in agricultural soils under Mediterranean conditions. This communications presents a preliminary evaluation of the top 1-m SOC content at two small, 8 and 6.7-ha, catchments in Southern Spain, covered by olive groves, that were intensively sampled in 2011. Spatial variability of SOC is analyzed across tree rows, areas in-between tree rows, and at different depths. The SOC distribution is evaluated against the topography of the catchment and the intensity of the water erosion processes analyzed by a simple model, such as SEDD, as used by Ferro and Porto (2000) and Taguas et al. (2011). The results of this communication will explore and discuss the differences between both catchments, and suggest guidelines for further exploring the sources of SOC variability, while providing guidelines to improve SOC estimation at the field scale for certification purposes.

  13. Lead contamination of an agricultural soil in the vicinity of a shooting range.

    PubMed

    Chrastný, Vladislav; Komárek, Michael; Hájek, Tomás

    2010-03-01

    In this study, coupled Pb concentration/Pb isotope data were used to evaluate the effect of a shooting range (operational for over 30 years) on Pb contamination of adjacent agricultural soils and the associated environmental risks. Lead was mainly concentrated in the arable layer of the contaminated agricultural soils at total concentrations ranging from 573 to 694 mg kg(-1). Isotopic analyses ((206)Pb/(207)Pb) proved that Pb originated predominantly from the currently used pellets. Chemical fractionation analyses showed that Pb was mainly associated with the reducible fraction of the contaminated soil, which is in accordance with its predominant soil phases (PbO, PbCO(3)). The 0.05 M EDTA extraction showed that up to 62% of total Pb from the contaminated site is potentially mobilizable. Furthermore, Pb concentrations obtained from the synthetic precipitation leaching procedure extraction exceeded the regulatory limit set by the United States Environmental Protection Agency for drinking water. Ion exchange resin bags showed to be inefficient for determining the vertical distribution of free Pb(2 + ) throughout the soil profile. Increased Pb concentrations were found in the biomass of spring barley (Hordeum vulgare L.) sampled at the studied site and two possible pathways of Pb uptake have been identified: (1) through passive diffusion-driven uptake by roots and (2) especially through atmospheric deposition, which was also proved by analyses of a bioindicator species (bryophyte Hypnum cupressiforme Hedw.). This study showed that shooting ranges can present an important source of Pb contamination of agricultural soils located in their close vicinity.

  14. Can conservation agriculture reduce the impact of soil erosion in northern Tunisia ?

    NASA Astrophysics Data System (ADS)

    Bahri, Haithem; Annabi, Mohamed; Chibani, Roukaya; Cheick M'Hamed, Hatem; Hermessi, Taoufik

    2016-04-01

    Mediterranean countries are prone to soil erosion, therefore Tunisia, with Mediterranean climate, is threatened by water erosion phenomena. In fact, 3 million ha of land is threatened by erosion, and 50% is seriously affected. Soils under conservation agriculture (CA) have high water infiltration capacities reducing significantly surface runoff and thus soil erosion. This improves the quality of surface water, reduces pollution from soil erosion, and enhances groundwater resources. CA is characterized by three interlinked principles, namely continuous minimum mechanical soil disturbance, permanent organic soil cover and diversification of crop species grown in sequence or associations. Soil aggregate stability was used as an indicator of soil susceptibility to water erosion. Since 1999, In Tunisia CA has been introduced in rainfed cereal areas in order to move towards more sustainable agricultural systems. CA areas increased from 52 ha in 1999 to 15000 ha in 2015. The objective of this paper is to study the effect of CA on soil erosion in northern Tunisia. Soil samples were collected at 10 cm of depth from 6 farmers' fields in northern Tunisia. Conventional tillage (CT), CA during less than 5 years (CA<5 years) and CA during more than 5 years (CA>5 years) have been practiced in each farmers field experiment of wheat crop. Soil aggregate stability was evaluated according to the method described by Le Bissonnais (1996), results were expressed as a mean weight diameter (MWD); higher values of MWD indicate higher aggregate stability. Total organic carbon (TOC) was determined using the wet oxidation method of Walkley-Black. A significant increase in SOC content was observed in CA>5years (1.64 %) compared to CT (0.97 %). This result highlights the importance of CA to improve soil fertility. For aggregate stability, a net increase was observed in CA compared to CT. After 5 years of CA the MWD was increased by 16% (MWD=1.8 mm for CT and MWD=2.1 mm for CA<5years). No

  15. Estimating annual soil carbon loss in agricultural peatland soils using a nitrogen budget approach.

    PubMed

    Kirk, Emilie R; van Kessel, Chris; Horwath, William R; Linquist, Bruce A

    2015-01-01

    Around the world, peatland degradation and soil subsidence is occurring where these soils have been converted to agriculture. Since initial drainage in the mid-1800s, continuous farming of such soils in the California Sacramento-San Joaquin Delta (the Delta) has led to subsidence of up to 8 meters in places, primarily due to soil organic matter (SOM) oxidation and physical compaction. Rice (Oryza sativa) production has been proposed as an alternative cropping system to limit SOM oxidation. Preliminary research on these soils revealed high N uptake by rice in N fertilizer omission plots, which we hypothesized was the result of SOM oxidation releasing N. Testing this hypothesis, we developed a novel N budgeting approach to assess annual soil C and N loss based on plant N uptake and fallow season N mineralization. Through field experiments examining N dynamics during growing season and winter fallow periods, a complete annual N budget was developed. Soil C loss was calculated from SOM-N mineralization using the soil C:N ratio. Surface water and crop residue were negligible in the total N uptake budget (3 - 4 % combined). Shallow groundwater contributed 24 - 33 %, likely representing subsurface SOM-N mineralization. Assuming 6 and 25 kg N ha-1 from atmospheric deposition and biological N2 fixation, respectively, our results suggest 77 - 81 % of plant N uptake (129 - 149 kg N ha-1) was supplied by SOM mineralization. Considering a range of N uptake efficiency from 50 - 70 %, estimated net C loss ranged from 1149 - 2473 kg C ha-1. These findings suggest that rice systems, as currently managed, reduce the rate of C loss from organic delta soils relative to other agricultural practices.

  16. Estimating annual soil carbon loss in agricultural peatland soils using a nitrogen budget approach.

    PubMed

    Kirk, Emilie R; van Kessel, Chris; Horwath, William R; Linquist, Bruce A

    2015-01-01

    Around the world, peatland degradation and soil subsidence is occurring where these soils have been converted to agriculture. Since initial drainage in the mid-1800s, continuous farming of such soils in the California Sacramento-San Joaquin Delta (the Delta) has led to subsidence of up to 8 meters in places, primarily due to soil organic matter (SOM) oxidation and physical compaction. Rice (Oryza sativa) production has been proposed as an alternative cropping system to limit SOM oxidation. Preliminary research on these soils revealed high N uptake by rice in N fertilizer omission plots, which we hypothesized was the result of SOM oxidation releasing N. Testing this hypothesis, we developed a novel N budgeting approach to assess annual soil C and N loss based on plant N uptake and fallow season N mineralization. Through field experiments examining N dynamics during growing season and winter fallow periods, a complete annual N budget was developed. Soil C loss was calculated from SOM-N mineralization using the soil C:N ratio. Surface water and crop residue were negligible in the total N uptake budget (3 - 4 % combined). Shallow groundwater contributed 24 - 33 %, likely representing subsurface SOM-N mineralization. Assuming 6 and 25 kg N ha-1 from atmospheric deposition and biological N2 fixation, respectively, our results suggest 77 - 81 % of plant N uptake (129 - 149 kg N ha-1) was supplied by SOM mineralization. Considering a range of N uptake efficiency from 50 - 70 %, estimated net C loss ranged from 1149 - 2473 kg C ha-1. These findings suggest that rice systems, as currently managed, reduce the rate of C loss from organic delta soils relative to other agricultural practices. PMID:25822494

  17. Estimating Annual Soil Carbon Loss in Agricultural Peatland Soils Using a Nitrogen Budget Approach

    PubMed Central

    Kirk, Emilie R.; van Kessel, Chris; Horwath, William R.; Linquist, Bruce A.

    2015-01-01

    Around the world, peatland degradation and soil subsidence is occurring where these soils have been converted to agriculture. Since initial drainage in the mid-1800s, continuous farming of such soils in the California Sacramento-San Joaquin Delta (the Delta) has led to subsidence of up to 8 meters in places, primarily due to soil organic matter (SOM) oxidation and physical compaction. Rice (Oryza sativa) production has been proposed as an alternative cropping system to limit SOM oxidation. Preliminary research on these soils revealed high N uptake by rice in N fertilizer omission plots, which we hypothesized was the result of SOM oxidation releasing N. Testing this hypothesis, we developed a novel N budgeting approach to assess annual soil C and N loss based on plant N uptake and fallow season N mineralization. Through field experiments examining N dynamics during growing season and winter fallow periods, a complete annual N budget was developed. Soil C loss was calculated from SOM-N mineralization using the soil C:N ratio. Surface water and crop residue were negligible in the total N uptake budget (3 – 4 % combined). Shallow groundwater contributed 24 – 33 %, likely representing subsurface SOM-N mineralization. Assuming 6 and 25 kg N ha-1 from atmospheric deposition and biological N2 fixation, respectively, our results suggest 77 – 81 % of plant N uptake (129 – 149 kg N ha-1) was supplied by SOM mineralization. Considering a range of N uptake efficiency from 50 – 70 %, estimated net C loss ranged from 1149 – 2473 kg C ha-1. These findings suggest that rice systems, as currently managed, reduce the rate of C loss from organic delta soils relative to other agricultural practices. PMID:25822494

  18. Molecular detection of Pythium insidiosum from soil in Thai agricultural areas.

    PubMed

    Vanittanakom, Nongnuch; Szekely, Jidapa; Khanthawong, Sophit; Sawutdeechaikul, Pritsana; Vanittanakom, Pramote; Fisher, Matthew C

    2014-05-01

    Pythium insidiosum is an aquatic fungus-like organism in the kingdom Stramenopila that causes pythiosis in both humans and animals. Human pythiosis occurs in ocular, localized granulomatous subcutaneous and systemic or vascular forms. Individuals whose occupations involve exposure to aquatic habitats have an elevated risk of contracting pythiosis. Previously, we reported the first successful isolation of Pythium insidiosum from aquatic environmental samples by culture including confirmation using molecular methods. In this study, we show that P. insidiosum inhabitats moist soil environments in agricultural areas. A total of 303 soil samples were collected from 25 irrigation sources in the areas nearby the recorded home addresses of pythiosis patients residing in northern provinces of Thailand. P. insidiosum DNA was identified directly from each soil extract by using a nested PCR assay and subsequent phylogenetic analysis of the ribosomal intragenic spacer region. P. insidiosum DNA could be detected from 16 of the 25 soil sources (64%). Conventional culture methods were also performed, however all samples exhibited negative culture results. We conclude that both irrigation water and soil are the natural reservoirs of P. insidiosum. In endemic areas, the exposure to these environmental reservoirs should be considered a risk factor for hosts susceptible to pythiosis. PMID:24444720

  19. Molecular detection of Pythium insidiosum from soil in Thai agricultural areas.

    PubMed

    Vanittanakom, Nongnuch; Szekely, Jidapa; Khanthawong, Sophit; Sawutdeechaikul, Pritsana; Vanittanakom, Pramote; Fisher, Matthew C

    2014-05-01

    Pythium insidiosum is an aquatic fungus-like organism in the kingdom Stramenopila that causes pythiosis in both humans and animals. Human pythiosis occurs in ocular, localized granulomatous subcutaneous and systemic or vascular forms. Individuals whose occupations involve exposure to aquatic habitats have an elevated risk of contracting pythiosis. Previously, we reported the first successful isolation of Pythium insidiosum from aquatic environmental samples by culture including confirmation using molecular methods. In this study, we show that P. insidiosum inhabitats moist soil environments in agricultural areas. A total of 303 soil samples were collected from 25 irrigation sources in the areas nearby the recorded home addresses of pythiosis patients residing in northern provinces of Thailand. P. insidiosum DNA was identified directly from each soil extract by using a nested PCR assay and subsequent phylogenetic analysis of the ribosomal intragenic spacer region. P. insidiosum DNA could be detected from 16 of the 25 soil sources (64%). Conventional culture methods were also performed, however all samples exhibited negative culture results. We conclude that both irrigation water and soil are the natural reservoirs of P. insidiosum. In endemic areas, the exposure to these environmental reservoirs should be considered a risk factor for hosts susceptible to pythiosis.

  20. [Analysis of heavy metals distribution characteristics and pollution assessment in agricultural region soils of Huaihe basin].

    PubMed

    Xiao, Xue; Zhao, Nan-Jing; Yuan, Jing; Ma, Ming-Jun; Fang, Li; Wang, Yin; Meng, De-Shuo; Yu, Yang; Tang, Jie; Zhang, Xiao-Ling; Dai, Yuan; Zhang, Yu-Jun; Liu, Jian-Guo; Liu, Wen-Qing

    2014-07-01

    By means of field sampling and laboratory analysis, the content distribution characteristics of Cd, Cr, Cu, Ni, Pb and Zn in agricultural region soils of Huaihe basin in Anhui province were analyzed. Assessment of heavy metal pollutions was conducted using enrichment factor, geoaccumulation index and potential ecological risk index. The results showed that the average mass fraction of Cd and Cu was 0.113 5 and 22.09 mg x kg(-1) respectively in the study area soil, which were above the background values 0.097 and 20.4 mg x kg(-1) in Anhui Province. The average mass fraction of other four heavy metals did not exceed the average values of Anhui Province. The results of the evaluations from geoaccumulation index and ecological risk assessment discovered that Cd is the strongest pollution metal among six heavy metals in the study area soil. For some samples of the study soil, Cd was slight risk for the ecosystem. The ecosystem risks caused by the other five heavy metals were not obviously for the sampling points. The entire study area soils were mid integrated potential ecological risk.

  1. Spatial distributions and seasonal variations of organochlorine pesticides in water and soil samples in Bolu, Turkey.

    PubMed

    Karadeniz, Hatice; Yenisoy-Karakaş, Serpil

    2015-03-01

    In this study, a total of 75 water samples (38 groundwater and 37 surface water samples) and 54 surface soil samples were collected from the five districts of Bolu, which is located in the Western Black Sea Region of Turkey in the summer season of 2009. In the autumn season, 17 water samples (surface water and groundwater samples) and 17 soil samples were collected within the city center to observe the seasonal changes of organochlorine pesticides (OCPs). Groundwater and surface water samples were extracted using solid phase extraction. Soil samples were extracted ultrasonically. Sixteen OCP compounds in the standard solution were detected by a gas chromatography-electron capture detector (GC-ECD). Therefore, the method validation was performed for those 16 OCP compounds. However, 13 OCP compounds could be observed in the samples. The concentrations of most OCPs were higher in samples collected in the summer than those in the autumn. The most frequently observed pesticides were endosulfan sulfate and 4,4'-dichlorodiphenyltrichloroethane (DDT) in groundwater samples, α-HCH in surface water samples, and endosulfan sulfate in soil samples. The average concentration of endosulfan sulfate was the highest in water and soil samples. Compared to the literature values, the average concentrations in this study were lower values. Spatial distribution of OCPs was evaluated with the aid of contour maps for the five districts of Bolu. Generally, agricultural processes affected the water and soil quality in the region. However, non-agricultural areas were also affected by pesticides. The concentrations of pesticides were below the legal limits of European directives for each pesticide.

  2. Tylosin-resistant bacteria cultivated from agricultural soil.

    PubMed

    Onan, Leslie J; LaPara, Timothy M

    2003-03-14

    In this study we analyzed the numbers and types of cultivable tylosin-resistant bacteria from six agricultural soils that differed with respect to their association with subtherapeutic antibiotic use. The proportion of tylosin-resistant bacteria to the total number of bacteria cultivated was significantly higher (7.2-16.5%) at three sites affected by subtherapeutic antibiotic use compared to three sites unaffected by subtherapeutic antibiotic use (0.7-2.5%). We also detected differences in the types of cultivable tylosin-resistant bacteria. At a site affected by subtherapeutic antibiotic use, we detected tylosin-resistant bacteria from the alpha- and beta-subdivisions of Proteobacteria. In contrast, at a site unaffected by subtherapeutic use, we detected only Streptomyces-like (high-G+C Gram-positive) tylosin-resistant bacteria. Our results suggest a link between subtherapeutic use of antibiotics and the numbers and types of antibiotic-resistant bacteria in nearby soil. However, other factors, such as soil type and temporal variation, may have also contributed to the differences observed.

  3. Prehistoric agricultural depletion of soil nutrients in Hawai'i

    PubMed Central

    Hartshorn, A. S.; Chadwick, O. A.; Vitousek, P. M.; Kirch, P. V.

    2006-01-01

    We investigated the fate of soil nutrients after centuries of indigenous dryland agriculture in Hawai‘i using a coupled geochemical and archaeological approach. Beginning ≈500 years ago, farmers began growing dryland taro and sweet potato on the leeward slopes of East Maui. Their digging sticks pierced a subsurface layer of cinders, enhancing crop access to the soil water stored below the intact cinders. Cultivation also catalyzed nutrient losses, directly by facilitating leaching of mobile nutrients after disturbing a stratigraphic barrier to vertical water movement, and indirectly by increasing mineral weathering and subsequent uptake and harvest. As a result, centuries of cultivation lowered volumetric total calcium, magnesium, sodium, potassium, and phosphorus content by 49%, 28%, 75%, 37%, and 32%, respectively. In the absence of written records, we used the difference in soil phosphorus to estimate that prehistoric yields were sufficient to meet local demand over very long time frames, but the associated acceleration of nutrient losses could have compromised subsequent yields. PMID:16832047

  4. [Soil Phosphorus Forms and Leaching Risk in a Typically Agricultural Catchment of Hefei Suburban].

    PubMed

    Fan, Hui-hui; Li, Ru-zhong; Pei, Ting-ting; Zhang, Rui-gang

    2016-01-15

    To investigate the soil phosphorus forms and leaching risk in a typically agricultural catchment of Ershibu River in Hefei Suburban, Chaohu Lake basin, 132 surface soil samples were collected from the catchment area. The spatial distribution of total phosphorus (TP) and bio-available phosphorus (Bio-P), and the spatial variability of soil available phosphorus (Olsen-P) and easy desorption phosphorus (CaCl2-P) were analyzed using the Kriging technology of AreGIS after speciation analysis of soil phosphorus. Moreover, the enrichment level of soil phosphorus was studied, and the phosphorus leaching risk was evaluated through determining the leaching threshold value of soil phosphorus. The results showed that the samples with high contents of TP and Bio-P mainly located in the upstream of the left tributary and on the right side of local area where two tributaries converged. The enrichment rates of soil phosphorus forms were arranged as follows: Ca-P (15.01) > OP (4.16) > TP (3. 42) > IP (2.94) > Ex-P (2.76) > Fe/Al-P (2.43) > Olsen-P (2.34). The critical value of Olsen-P leaching was 18.388 mg x kg(-1), and the leaching samples with values higher than the threshold value accounted for 16.6% of total samples. Generally, the high-risk areas mainly occurred in the upstream of the left tributary, the middle of the right tributary and the local area of the downstream of the area where two tributaries converged.

  5. The use of biogas plant fermentation residue for the stabilisation of toxic metals in agricultural soils

    NASA Astrophysics Data System (ADS)

    Geršl, Milan; Šotnar, Martin; Mareček, Jan; Vítěz, Tomáš; Koutný, Tomáš; Kleinová, Jana

    2015-04-01

    Our department has been paying attention to different methods of soil decontamination, including the in situ stabilisation. Possible reagents to control the toxic metals mobility in soils include a fermentation residue (FR) from a biogas plant. Referred to as digestate, it is a product of anaerobic decomposition taking place in such facilities. The fermentation residue is applied to soils as a fertiliser. A new way of its use is the in situ stabilisation of toxic metals in soils. Testing the stabilisation of toxic metals made use of real soil samples sourced from five agriculturally used areas of the Czech Republic with 3 soil samples taken from sites contaminated with Cu, Pb and Zn and 2 samples collected at sites of natural occurrence of Cu, Pb and Zn ores. All the samples were analysed using the sequential extraction procedure (BCR) (determine the type of Cu, Pb and Zn bonds). Stabilisation of toxic metals was tested in five soil samples by adding reagents as follows: dolomite, slaked lime, goethite, compost and fermentation residue. A single reagent was added at three different concentrations. In the wet state with the added reagents, the samples were left for seven days, shaken twice per day. After seven days, metal extraction was carried out: samples of 10 g soil were shaken for 2 h in a solution of 0.1M NH4NO3 at a 1:2.5 (g.ml-1), centrifuged for 15 min at 5,000 rpm and then filtered through PTFE 0.45 μm mesh filters. The extracts were analysed by ICP-OES. Copper The best reduction of Cu concentration in the extract was obtained at each of the tested sites by adding dolomite (10 g soil + 0.3 g dolomite). The concentration of Cu in the leachate decreased to 2.1-18.4% compare with the leachate without addition. Similar results were also shown for the addition of fermentation residue (10 g soil + 1 g FR). The Cu concentration in the leachate decreased to 16.7-26.8% compared with the leachate without addition. Lead The best results were achieved by adding

  6. Estimating the Soil Thermal Conductivity in a Agricultural Crop Site in Southern Brazil

    NASA Astrophysics Data System (ADS)

    Zimmer, Tamíres; Roberti, Debora; Moreira, Virnei; Silveira, Marcos

    The thermal conductivity is higher when the heat storage is higher and the soil surface temperature is lower. The soil thermal conductivity is also dependant on the soil texture, porosity and moisture. Therefore, it varies from soil to soil and in the same soil, depending on its soil moisture. In the present work, it is shown soil thermal conductivity estimates in a agricultural crop located at the Cruz Alta city in southern Brazil. Also the dynamic of soil heat flux (G) is analyzed and the soil thermal conductivity (Ks) is estimated using experimental data form soil heat flux and soil temperature in a agricultural crop farm in a subtropical location in Southern Brazil. In this specific site, there is a crop rotation scheme along the year. The soil type is Rhodic Hapludox (FAO) or Typic Haplorthox (US Soil Taxonomy), characterized as a deep, clay soil. The experimental soil heat flux was compared with estimated soil heat flux by two forms: (1) using a known Ks from literature for this type of soil; (2) using Ks estimated using the inversion of the equation Qg=-ks* ((T2-T1)/ (Z2-Z1)), where T1 and T2 are the temperature in different layers above the soil and Z2-Z1 is the difference between the positions in temperature measurement. The general results agree with the literature for the specific agricultural crop for Ks values in the current study for the measurement period.

  7. Carbon and Phosphorus in soil particulate fraction: effect of continuous agriculture, tillage and fertilization

    NASA Astrophysics Data System (ADS)

    Wyngaard, N.; Echeverrıa, H. E.; Vidaurreta, A.; Picone, L. I.; Divito, G. A.

    2012-04-01

    In Argentinean Pampas region, the practice of intensive agriculture has diminished total organic carbon (TOC) content in soil. This degradation process can impact over phosphorus (P) organic fractions associated to it, and therefore limit soil capacity to provide P through mineralization. Along this line, P content in soil particulate fraction (PF) has been proposed as an index to estimate this capacity. The aims of this work were to evaluate (1) the effect of continuous agriculture, tillage and P fertilization over TOC and P fractions content in soil and PF, and (2) the stability of P-PF as a mineralization index. To this end, a long term experiment initiated in 2001 in Balcarce, Argentina, under continuous agriculture, was analyzed. There, two tillage systems - conventional till (CT) and no till (NT) - and two fertilization treatments - nitrogen (N) and N + P (NP) - were evaluated. Phosphorus rate was 30 kg ha-1 year-1. In each plot, the following parameters were determined in 2002, 2005, 2008 and 2011: TOC, P Bray, total P (Pt), inorganic P (Pi), and organic P (Po) content in the whole soil and in the PF. Also, C supply by residues and P soil balance during the experiment were calculated, and the P sorption capacity was determined in samples from 2011. C supply was greater in CT (7% relative to NT) and in NP (14% relative to N). However, TOC in soil was not modified neither by tillage or fertilization. Even though, C in the PF decreased (3% annually) by the use of continuous agriculture. This reduction was positively associated to the one observed in other soil properties as Pt, Pi and Po in the PF. P fertilization lessened this reduction in Pt (18,9 mg kg-1 in N and 23,1 mg kg-1 in NP in 2011) and Pi (4,2 mg kg-1 in N and 6,2 mg kg-1 in NP in 2011), but not in Po. This indicates that, Po is affected by management practices and, contrary to Pt, is stable to fertilization. Therefore Po can be studied as a potential P mineralization index. The difference among P

  8. Nitrogen Turnover Processes in Low Temperatures in an Agricultural Peat Soil

    NASA Astrophysics Data System (ADS)

    Silvennoinen, H. M.; Hämäläinen, R.; Koponen, H. T.; Martikainen, P. J.

    2009-12-01

    Nitrogen (N) cycling in agricultural soils has a key impact on the environment. Agricultural ecosystems are the most important sources of nitrous oxide (N2O), an important greenhouse gas, to the atmosphere. Additionally N fertilizers used to improve plant growth lead to enhanced N leaching and thereby to eutrophication of surrounding aquatic ecosystems. Microbial processes are normally enhanced by increase in temperature. Several recent studies have shown that although N2O emissions from agricultural soils are of microbiological origin, produced mainly in microbial reduction of nitrate (NO3-) via nitric oxide (NO) and N2O to molecular nitrogen (N2) (denitrification), the temperature response of N2O emissions is greatly variable and there is a lot of evidence of high emissions during cold periods (Koponen et al. 2006). Denitrification is, however, regulated by availability of inorganic N and therefore dependant not only on N fertilization but also on N turnover processes in soil. These processes include mineralization of organic N to ammonium (NH4+), oxidation of NH4+ to nitrite and NO3- (nitrification). These processes and their regulation especially in low temperatures are yet poorly understood. In this experiment, gross rates of N mineralization and nitrification and carbon dioxide production were studied in various temperatures ranging from -1.5 to 15 °C. Soil samples were taken from grassland on peat soil in Southern Finland (60o49’N, 23o30’E) on September 8th 2008 from depths of 0-10 cm. Temperature responses of N gross mineralization and nitrification and of microbial respiration were measured in a laboratory experiment. The incubation temperatures used for experiments were 15, 5, 2.5, 1.5, 0.5, 0, -0.5 and -1.5 °C. After 7 d temperature-specific incubation, gross rates of N mineralization and nitrification were determined with pool dilution technique in a 24 h incubation experiment. This study showed that N turnover processes in agricultural peat soil

  9. 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.

  10. Validating a high-resolution digital soil map for precision agriculture across multiple fields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Digital soil mapping (DSM) for precision agriculture (PA) management is aimed at developing models that predict soil properties or classes using legacy soil data, sensors, and environmental covariates. The utility of DSM for PA is based on its ability to provide useful spatial soil information for o...

  11. Assessing microbial activities in metal contaminated agricultural volcanic soils--An integrative approach.

    PubMed

    Parelho, C; Rodrigues, A S; Barreto, M C; Ferreira, N G C; Garcia, P

    2016-07-01

    Volcanic soils are unique naturally fertile resources, extensively used for agricultural purposes and with particular physicochemical properties that may result in accumulation of toxic substances, such as trace metals. Trace metal contaminated soils have significant effects on soil microbial activities and hence on soil quality. The aim of this study is to determine the soil microbial responses to metal contamination in volcanic soils under different agricultural land use practices (conventional, traditional and organic), based on a three-tier approach: Tier 1 - assess soil microbial activities, Tier 2 - link the microbial activity to soil trace metal contamination and, Tier 3 - integrate the microbial activity in an effect-based soil index (Integrative Biological Response) to score soil health status in metal contaminated agricultural soils. Our results showed that microbial biomass C levels and soil enzymes activities were decreased in all agricultural soils. Dehydrogenase and β-glucosidase activities, soil basal respiration and microbial biomass C were the most sensitive responses to trace metal soil contamination. The Integrative Biological Response value indicated that soil health was ranked as: organic>traditional>conventional, highlighting the importance of integrative biomarker-based strategies for the development of the trace metal "footprint" in Andosols. PMID:27057992

  12. Continuous Passive Sampling of Solutes from Agricultural Subsurface Drainage Tubes

    NASA Astrophysics Data System (ADS)

    Lindblad Vendelboe, Anders; de Jonge, Hubert; Rozemeijer, Joachim; Wollesen de Jonge, Lis

    2015-04-01

    Agricultural subsurface tube drain systems play an important role in water and solute transport. One study, focusing on lowland agricultural catchments, showed that subsurface tube drainage contributed up to 80% of the annual discharge and 90% of the annual NO3 load from agricultural fields to the receiving water bodies. Knowledge of e.g. nutrient loads and drainage volumes, based on measurements and modelling, are important for adequate water quality management. Despite the importance of tube drain transport of solutes, monitoring data are scarce. This scarcity is a result of the existing monitoring techniques for flow and contaminant load from tube drains being expensive and labor-extensive. The study presented here aimed at developing a cheap, simple, and robust method to monitor solute loads from tube drains. The method is based on the newly developed Flowcap, which can be attached to existing tube drain outlets and can measure total flow, contaminant load and flow-averaged concentrations of solutes in the drainage. The Flowcap builds on the existing Sorbicell principle, a passive sampling system that measures average concentrations over longer periods of time (days to months) for various compounds. The Sorbicell consists of two compartments permeable to water. One compartment contains an adsorbent and one contains a tracer. When water passes through the Sorbicell the compound of interest is absorbed while a tracer is released. Using the tracer loss to calculate the volume of water that has passed the Sorbicell it is possible to calculate the average concentration of the compound. When mounting Sorbicells in the Flowcap, a flow-proportional part of the drainage is sampled from the main stream. To accommodate the wide range of drainage flow rates two Flowcaps with different capacities were tested in the laboratory: one with a capacity of 25 L min-1 (Q25) and one with a capacity of 256 L min-1 (Q256). In addition, Sorbicells with two different hydraulic

  13. Sensitive time-resolved fluoroimmunoassay for quantitative determination of clothianidin in agricultural samples.

    PubMed

    Li, Ming; Sheng, Enze; Yuan, Yulong; Liu, Xiaofeng; Hua, Xiude; Wang, Minghua

    2014-05-01

    Europium (Eu(3+))-labeled antibody was used as a fluorescent label to develop a highly sensitive time-resolved fluoroimmunoassay (TRFIA) for determination of clothianidin residues in agricultural samples. Toward this goal, the Eu(3+)-labeled polyclonal antibody and goat anti-rabbit antibody were prepared for developing and evaluating direct competitive TRFIA (dc-TRFIA) and indirect competitive TRFIA (ic-TRFIA). Under optimal conditions, the half-maximal inhibition concentration (IC50) and the limit of detection (LOD, IC10) of clothianidin were 9.20 and 0.0909 μg/L for the dc-TRFIA and 2.07 and 0.0220 μg/L for the ic-TRFIA, respectively. The ic-TRFIA has no obvious cross-reactivity with the analogues of clothianidin except for dinotefuran. The average recoveries of clothianidin from spiked water, soil, cabbage, and rice samples were estimated to range from 74.1 to 115.9 %, with relative standard deviations of 3.3 to 11.7 %. The results of TRFIA for the blind samples were largely consistent with gas chromatography (R (2) = 0.9902). The optimized ic-TRFIA might become a sensitive and satisfactory analytical method for the quantitative monitoring of clothianidin residues in agricultural samples.

  14. Rapid screening of flonicamid residues in environmental and agricultural samples by a sensitive enzyme immunoassay.

    PubMed

    Liu, Zhenjiang; Zhang, Zhen; Zhu, Gangbing; Sun, Jianfan; Zou, Bin; Li, Ming; Wang, Jiagao

    2016-05-01

    A fast and sensitive polyclonal antibody-based enzyme-linked immunosorbent assay (ELISA) was developed for the analysis of flonicamid in environmental and agricultural samples. Two haptens of flonicamid differing in spacer arm length were synthesized and conjugated to proteins to be used as immunogens for the production of polyclonal antibodies. To obtain most sensitive combination of antibody/coating antigen, two antibodies were separately screened by homologous and heterologous assays. After optimization, the flonicamid ELISA showed that the 50% inhibitory concentration (IC50 value) was 3.86mgL(-1), and the limit of detection (IC20 value) was 0.032mgL(-1). There was no cross-reactivity to similar tested compounds. The recoveries obtained after the addition of standard flonicamid to the samples, including water, soil, carrot, apple and tomato, ranged from 79.3% to 116.4%. Moreover, the results of the ELISA for the spiked samples were largely consistent with the gas chromatography (R(2)=0.9891). The data showed that the proposed ELISA is an alternative tool for rapid, sensitive and accurate monitoring of flonicamid in environmental and agricultural samples. PMID:26897400

  15. Estimation of uncertainty arising from different soil sampling devices: the use of variogram parameters.

    PubMed

    de Zorzi, Paolo; Barbizzi, Sabrina; Belli, Maria; Barbina, Maria; Fajgelj, Ales; Jacimovic, Radojko; Jeran, Zvonka; Menegon, Sandro; Pati, Alessandra; Petruzzelli, Giannantonio; Sansone, Umberto; Van der Perk, Marcel

    2008-01-01

    In the frame of the international SOILSAMP project, funded and coordinated by the National Environmental Protection Agency of Italy (APAT), uncertainties due to field soil sampling were assessed. Three different sampling devices were applied in an agricultural area using the same sampling protocol. Cr, Sc and Zn mass fractions in the collected soil samples were measured by k(0)-instrumental neutron activation analysis (k(0)-INAA). For each element-device combination the experimental variograms were calculated using geostatistical tools. The variogram parameters were used to estimate the standard uncertainty arising from sampling. The sampling component represents the dominant contribution of the measurement uncertainty with a sampling uncertainty to measurement uncertainty ratio ranging between 0.6 and 0.9. The approach based on the use of variogram parameters leads to uncertainty values of the sampling component in agreement with those estimated by replicate sampling approach.

  16. Nitrous oxide emissions in southern Poland from agricultural soils under various tillage conditions and from urban soils under strong anthropopression

    NASA Astrophysics Data System (ADS)

    Galkowski, M.; Bartyzel, J.; Zięba, D.; Ciaciek, K.; Nęcki, J. M.

    2015-12-01

    We present the results of field measurements performed at: (i) the agricultural sites managed by Institute of Plant Acclimatization and Husbandry (ZDHAR) in Grodkowice (Malopolska, Poland), and (ii) the urban sites located in Kraków, Poland. For agricultural measurements, several sites have been selected for measurements of N2O emissions during two campaigns - in spring and autumn 2014. The investigated crops were chosen to represent the regional agriculture and included wheat, canola and maize under various tillage conditions, as well as an uncultivated grassland as a control site. For urban environment, measurement campaigns have been performed at the university's campus lawn and at a large urban meadow, both located in the centre of Kraków agglomeration. The sites were chosen to be representative of the urban green areas typical of Central Europe. The static chamber method was chosen to quantify soil-atmosphere N2O fluxes. Chamber enclosures have been performed every 3-5 days, depending on the conditions prevailing at the sites during the intermediate periods. From each enclosure, five 50-ml air samples have been collected for subsequent analysis of nitrous oxide concentrations. Well-established gas chromatography methods, with a precision of a single N2O measurement better than 0.5 ppb were employed. The measured concentrations were then used in a linear emission model to calculate N2O fluxes. Results of agricultural campaigns show large variability of N2O emissions, with maximum fluxes in the order of 120 ng N-N2O m-2 s-1, driven mainly by availability of nitrogen in soil and water. For fertilized sites, largest emissions values were observed several days after the rainfall events. Notable differences between sites under alternative tillage techniques have been observed. Observations at the urban sites revealed significant fluxes of N2O, with average daily values in some cases exceeding those observed at agricultural fields.

  17. Soil separator and sampler and method of sampling

    DOEpatents

    O'Brien, Barry H [Idaho Falls, ID; Ritter, Paul D [Idaho Falls, ID

    2010-02-16

    A soil sampler includes a fluidized bed for receiving a soil sample. The fluidized bed may be in communication with a vacuum for drawing air through the fluidized bed and suspending particulate matter of the soil sample in the air. In a method of sampling, the air may be drawn across a filter, separating the particulate matter. Optionally, a baffle or a cyclone may be included within the fluidized bed for disentrainment, or dedusting, so only the finest particulate matter, including asbestos, will be trapped on the filter. The filter may be removable, and may be tested to determine the content of asbestos and other hazardous particulate matter in the soil sample.

  18. Parameters affecting microwave-assisted extraction of organophosphorus pesticides from agricultural soil.

    PubMed

    Fuentes, Edwar; Báez, María E; Labra, Ronnie

    2007-10-26

    This work describes an optimised method for the determination of six representative organophosphorus pesticides (OPPs) (diazinon, parathion, methyl pirimiphos, methyl parathion, ethoprophos, and fenitrothion) in agricultural soils. The method is based on microwave-assisted extraction using a water-methanol modified mixture for desorption and simultaneous partitioning on n-hexane (MAEP), together with gas chromatography-flame photometric detection (GC-FPD). To improve GC-FPD signals (peak intensity and shape) olive oil was used effectively as a "matrix mimic". The optimisation of the extraction method was achieved in two steps: an initial approach through experimental design and principal component analysis where recovery of compounds using a water-methanol mixture ranged from 54 to 77%, and the second one by studying the addition of KH2PO4 to the extracting solution where recoveries were significantly increased, molecular replacing of OPPs from adsorption sites by phosphate being the probable extraction mechanism. Under optimised conditions, recoveries of pesticides from different soils were higher than 73%, except for methyl parathion in some soils, with SD equal or lower than 11% and detection limits ranging from 0.004 to 0.012 microg g(-1). The proposed method was used to determine OPPs in soil samples from different agricultural zones of Chile.

  19. Influence of sustainable management on aggregate stability and soil organic matter on agricultural soil of southern Spain

    NASA Astrophysics Data System (ADS)

    Morugan-Coronado, Alicia; Arcenegui, Victoria; Mataix-Solera, Jorge; Gomez-Lucas, Ignacio; Garcia-Orenes, Fuensanta

    2016-04-01

    Intensive agriculture has increased crop yields but also posed severe environmental problems. Unsustainable land management such as excessive tillage can lead to a loss of soil fertility and a drastic reduction in the aggregate stability and soil organic matter content. However sustainable agriculture can keep good crop yields with minimal impact on ecological factors conserving the soil quality and its ecosystem services. Sustainable agriculture management promotes the maintenance of soil organic matter levels providing plant nutrients through the microbial decomposition of organic materials. Also this management has a positive effect on soil structure with the improvement of stability of aggregates. The resistance of soil aggregates to the slaking and dispersive effects of water (aggregate stability) is important for maintaining the structure in arable soils. Our purpose was to investigate and compare the effects of sustainable agricultural practices versus intensive agriculture on aggregate stability and soil organic matter. Three agricultural areas are being monitored in the southern of Spain, two of them with citrus orchards (AL) and (FE) and one with grapevine(PA). In all of them two agricultural treatments are being developed, organic with no-tillage management(O) and inorganic fertilization with herbicide application and intensive tillage (I). The sustainable agricultural management (manure, no tillage and vegetation cover) contributed to the improve of soil conditions, increasing organic matter and aggregate stability. Meanwhile, herbicide treatment and intensive tillage with inorganic fertilization managements resulted in the decreasing of aggregate stability and low levels of soil organic carbon. Soil organic matter content is generally low in all unsustainable treatments plots and tends to decline in aggregate stability and soil physical condition. In both treatments the crop yield are comparable.

  20. Use of airborne hyperspectral imagery to map soil parameters in tilled agricultural fields

    USGS Publications Warehouse

    Hively, W. Dean; McCarty, Gregory W.; Reeves, James B.; Lang, Megan W.; Oesterling, Robert A.; Delwiche, Stephen R.

    2011-01-01

    Soil hyperspectral reflectance imagery was obtained for six tilled (soil) agricultural fields using an airborne imaging spectrometer (400–2450 nm, ~10 nm resolution, 2.5 m spatial resolution). Surface soil samples (n = 315) were analyzed for carbon content, particle size distribution, and 15 agronomically important elements (Mehlich-III extraction). When partial least squares (PLS) regression of imagery-derived reflectance spectra was used to predict analyte concentrations, 13 of the 19 analytes were predicted with R2 > 0.50, including carbon (0.65), aluminum (0.76), iron (0.75), and silt content (0.79). Comparison of 15 spectral math preprocessing treatments showed that a simple first derivative worked well for nearly all analytes. The resulting PLS factors were exported as a vector of coefficients and used to calculate predicted maps of soil properties for each field. Image smoothing with a 3 × 3 low-pass filter prior to spectral data extraction improved prediction accuracy. The resulting raster maps showed variation associated with topographic factors, indicating the effect of soil redistribution and moisture regime on in-field spatial variability. High-resolution maps of soil analyte concentrations can be used to improve precision environmental management of farmlands.

  1. Landscape patterns and soil organic carbon stocks in agricultural bocage landscapes

    NASA Astrophysics Data System (ADS)

    Viaud, Valérie; Lacoste, Marine; Michot, Didier; Walter, Christian

    2014-05-01

    Soil organic carbon (SOC) has a crucial impact on global carbon storage at world scale. SOC spatial variability is controlled by the landscape patterns resulting from the continuous interactions between the physical environment and the society. Natural and anthropogenic processes occurring and interplaying at the landscape scale, such as soil redistribution in the lateral and vertical dimensions by tillage and water erosion processes or spatial differentiation of land-use and land-management practices, strongly affect SOC dynamics. Inventories of SOC stocks, reflecting their spatial distribution, are thus key elements to develop relevant management strategies to improving carbon sequestration and mitigating climate change and soil degradation. This study aims to quantify SOC stocks and their spatial distribution in a 1,000-ha agricultural bocage landscape with dairy production as dominant farming system (Zone Atelier Armorique, LTER Europe, NW France). The site is characterized by high heterogeneity on short distance due to a high diversity of soils with varying waterlogging, soil parent material, topography, land-use and hedgerow density. SOC content and stocks were measured up to 105-cm depth in 200 sampling locations selected using conditioned Latin hypercube sampling. Additive sampling was designed to specifically explore SOC distribution near to hedges: 112 points were sampled at fixed distance on 14 transects perpendicular from hedges. We illustrate the heterogeneity of spatial and vertical distribution of SOC stocks at landscape scale, and quantify SOC stocks in the various landscape components. Using multivariate statistics, we discuss the variability and co-variability of existing spatial organization of cropping systems, environmental factors, and SOM stocks, over landscape. Ultimately, our results may contribute to improving regional or national digital soil mapping approaches, by considering the distribution of SOC stocks within each modeling unit and

  2. Characteristic and potential sources of polychlorinated dibenzo-P-dioxins and dibenzofurans in agricultural soils in Beijing, China.

    PubMed

    Li, Wei; Li, Chaoqin; Chen, Zuosheng; Cai, Zongwei

    2014-09-01

    Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were analyzed in 25 background and 80 agricultural soil samples collected from 21 sites in Beijing, China. The levels of PCDD/Fs in the north agricultural soils were low (0.15-0.58 ng international toxic equivalent quantity [I-TEQ]/kg), which were comparable with those of the background soils (0.091-0.35 ng I-TEQ/kg). In the southern agricultural soils, however, concentrations were several times higher (0.27-3.3 ng I-TEQ/kg). Comparison of PCDD/Fs congener compositions between possible sources and samples indicated that agricultural soils in Beijing had not been contaminated by the 3 main PCDD/F contamination sources in China--ferrous and nonferrous metal, waste incineration, and power generation. They had, however, been slightly contaminated by the impurities of some organochlorine pesticides, such as sodium pentachlorophenate, and by open burning of biomass, vehicle exhaust, atmospheric deposition, sediment, and sewage sludge. These results have been supported by the principal components analysis.

  3. Soil classification basing on the spectral characteristics of topsoil samples

    NASA Astrophysics Data System (ADS)

    Liu, Huanjun; Zhang, Xiaokang; Zhang, Xinle

    2016-04-01

    Soil taxonomy plays an important role in soil utility and management, but China has only course soil map created based on 1980s data. New technology, e.g. spectroscopy, could simplify soil classification. The study try to classify soils basing on the spectral characteristics of topsoil samples. 148 topsoil samples of typical soils, including Black soil, Chernozem, Blown soil and Meadow soil, were collected from Songnen plain, Northeast China, and the room spectral reflectance in the visible and near infrared region (400-2500 nm) were processed with weighted moving average, resampling technique, and continuum removal. Spectral indices were extracted from soil spectral characteristics, including the second absorption positions of spectral curve, the first absorption vale's area, and slope of spectral curve at 500-600 nm and 1340-1360 nm. Then K-means clustering and decision tree were used respectively to build soil classification model. The results indicated that 1) the second absorption positions of Black soil and Chernozem were located at 610 nm and 650 nm respectively; 2) the spectral curve of the meadow is similar to its adjacent soil, which could be due to soil erosion; 3) decision tree model showed higher classification accuracy, and accuracy of Black soil, Chernozem, Blown soil and Meadow are 100%, 88%, 97%, 50% respectively, and the accuracy of Blown soil could be increased to 100% by adding one more spectral index (the first two vole's area) to the model, which showed that the model could be used for soil classification and soil map in near future.

  4. Effects of agricultural intensification in the tropics on soil carbon losses and soil fertility

    NASA Astrophysics Data System (ADS)

    Guillaume, Thomas; Buttler, Alexandre; Kuzyakov, Yakov

    2016-04-01

    Tropical forest conversion to agricultural land leads to strong decrease of soil organic carbon (SOC). Nonetheless, the impacts of SOC losses on soil fertility remain unclear. We quantified SOC losses in forest, oil palm plantations, extensive rubber plantations and rubber monocultures on Sumatra Island (Indonesia). Furthermore, we assessed the response of biological (basal respiration, microbial biomass, acid phosphatase) and chemical fertility indicators (light fraction of OM, DOC, total N, available P) to SOC losses. We used a new approach based on (non-)linear regressions between SOC losses and the indicators, normalized to natural ecosystem values, to assess the sensitivity or resistance of fertility indicators to SOC losses. Carbon contents in the Ah horizon under oil palm and intensive rubber plantations were strongly reduced: up to 70% and 62%, respectively. The decrease was lower under extensive rubber (41%). The negative impact of land-use changes on all measured indicators increased in the following sequence: extensive rubber < rubber < oil palm. Basal respiration, microbial biomass and nutrients were comparatively resistant to SOC losses, whereas the light fraction of OM was lost faster than the SOC. The resistance of the microbial activity to SOC losses is an indication that microbial-mediated soil functions sustain SOC losses. However, responses of basal respiration and microbial biomass to SOC losses were non-linear. Below 2.7% C content, the relationship was reversed. The basal respiration decreased faster than the SOC, resulting in a stronger drop of microbial activity under oil palm compared to rubber, despite small difference in C content. We conclude that the new approach allows a quantitative assessment of the sensitivity and threshold of various soil functions to land-use changes and consequently, can be used to assess their resistance to agricultural intensification. Therefore, this method is appropriate to evaluate the environmental impacts

  5. Classification and soil moisture determination of agricultural fields

    NASA Technical Reports Server (NTRS)

    Vandenbroek, A. C.; Groot, J. S.

    1993-01-01

    During the Mac-Europe campaign of 1991 several SAR (Synthetic Aperature Radar) experiments were carried out in the Flevoland test area in the Netherlands. The test site consists of a forested and an agricultural area with more than 15 different crop types. The experiments took place in June and July (mid to late growing season). The area was monitored by the spaceborne C-band VV polarized ERS-1, the Dutch airborne PHARS with similar frequency and polarization and the three-frequency PP-, L-, and C-band) polarimetric AIRSAR system of NASA/JPL. The last system passed over on June 15, 3, 12, and 28. The last two dates coincided with the overpasses of the PHARS and the ERS-1. Comparison of the results showed that backscattering coefficients from the three systems agree quite well. In this paper we present the results of a study of crop type classification (section 2) and soil moisture determination in the agricultural area (section 3). For these studies we used field averaged Stokes matrices extracted from the AIRSAR data (processor version 3.55 or 3.56).

  6. Potential of Biological Agents in Decontamination of Agricultural Soil

    PubMed Central

    Javaid, Muhammad Kashif; Ashiq, Mehrban; Tahir, Muhammad

    2016-01-01

    Pesticides are widely used for the control of weeds, diseases, and pests of cultivated plants all over the world, mainly since the period after the Second World War. The use of pesticides is very extensive to control harm of pests all over the globe. Persistent nature of most of the synthetic pesticides causes serious environmental concerns. Decontamination of these hazardous chemicals is very essential. This review paper elaborates the potential of various biological agents in decontamination of agricultural soils. The agricultural crop fields are contaminated by the periodic applications of pesticides. Biodegradation is an ecofriendly, cost-effective, highly efficient approach compared to the physical and chemical methods which are expensive as well as unfriendly towards environment. Biodegradation is sensitive to the concentration levels of hydrogen peroxide and nitrogen along with microbial community, temperature, and pH changes. Experimental work for optimum conditions at lab scale can provide very fruitful results about specific bacterial, fungal strains. This study revealed an upper hand of bioremediation over physicochemical approaches. Further studies should be carried out to understand mechanisms of biotransformation. PMID:27293964

  7. Potential of Biological Agents in Decontamination of Agricultural Soil.

    PubMed

    Javaid, Muhammad Kashif; Ashiq, Mehrban; Tahir, Muhammad

    2016-01-01

    Pesticides are widely used for the control of weeds, diseases, and pests of cultivated plants all over the world, mainly since the period after the Second World War. The use of pesticides is very extensive to control harm of pests all over the globe. Persistent nature of most of the synthetic pesticides causes serious environmental concerns. Decontamination of these hazardous chemicals is very essential. This review paper elaborates the potential of various biological agents in decontamination of agricultural soils. The agricultural crop fields are contaminated by the periodic applications of pesticides. Biodegradation is an ecofriendly, cost-effective, highly efficient approach compared to the physical and chemical methods which are expensive as well as unfriendly towards environment. Biodegradation is sensitive to the concentration levels of hydrogen peroxide and nitrogen along with microbial community, temperature, and pH changes. Experimental work for optimum conditions at lab scale can provide very fruitful results about specific bacterial, fungal strains. This study revealed an upper hand of bioremediation over physicochemical approaches. Further studies should be carried out to understand mechanisms of biotransformation. PMID:27293964

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

    NASA Astrophysics Data System (ADS)

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

    2010-05-01

    Soil salinization is one of the main problems in many soils under intensive agricultural practices, especially in arid and semiarid zones. Two important reasons for the occurrence of salinization are i) the use of low quality irrigation water and ii) climatic conditions reducing soil quality. The results of salinization can be quite serious. It limits the growing of crops, constrains agricultural productivity, and in severe cases, leads to the abandonment of agricultural soils. There are mainly two kinds of soil salinity: naturally occurring dry-land salinity and human-induced salinity caused by the low quality of irrigation water, excessive water and fertilizer applications. In both cases the development of plants and soil organisms is limited. Natural occurrence of salts in soils is very difficult to handle and requires higher investments than the reduction of human-induced salinity. For these reasons, identification of vulnerable sites is essential for sustainable agricultural management, especially in these semiarid and arid environments. The main aim of this study was to examine spatial and vertical distribution pattern of salts in a semi-arid study site in South-Eastern Spain in order to identify vulnerable sites. In order to achieve this objective, surface soil samples were collected in January and July 2009 at 48 sites located in a representative lemon production area close to City of Murcia, covering a surface area of 44 km2. The area was divided using a square grid of 1000 m and the samples were taken from these squares. The ionic concentrations were used as the input data for distribution maps. The software used for the spatial analysis was Arcview 3.1. An interpolation method called the Inverse Distanced Weighted (IDW) method was adopted for the interpolation of the data. The results indicated that the concentrations of most anions are higher in summer. The difference was particularly large for chloride, most likely because of its high mobility and

  9. Fractionation of trace elements in agricultural soils using ultrasound assisted sequential extraction prior to inductively coupled plasma mass spectrometric determination.

    PubMed

    Matong, Joseph M; Nyaba, Luthando; Nomngongo, Philiswa N

    2016-07-01

    The main objectives of this study were to determine the concentration of fourteen trace elements and to investigate their distribution as well as a contamination levels in selected agricultural soils. An ultrasonic assisted sequential extraction procedure derived from three-step BCR method was used for fractionation of trace elements. The total concentration of trace elements in soil samples was obtained by total digestion method in soil samples with aqua regia. The results of the extractable fractions revealed that most of the target trace elements can be transferred to the human being through the food chain, thus leading to serious human health. Enrichment factor (EF), geo-accumulation index (Igeo), contamination factor (CF), risk assessment code (RAC) and individual contamination factors (ICF) were used to assess the environmental impacts of trace metals in soil samples. The EF revealed that Cd was enriched by 3.1-7.2 (except in Soil 1). The Igeo results showed that the soils in the study area was moderately contaminated with Fe, and heavily to extremely polluted with Cd. The soil samples from the unplanted field was found to have highest contamination factor for Cd and lowest for Pb. Soil 3 showed a high risk for Tl and Cd with RAC values of greater than or equal to 50%. In addition, Fe, Ni, Cu, V, As, Mo (except Soil 2), Sb and Pb posed low environmental risk. The modified BCR sequential extraction method provided more information about mobility and environmental implication of studied trace elements in the study area.

  10. Implication of soil C sequestration on sustainable agriculture and environment.

    PubMed

    Mondini, C; Sequi, P

    2008-01-01

    Soil organic matter (SOM) is the largest C stock of the continental biosphere with 1550Pg. The size of C reservoir in the soil and environmental concerns on climate change have recently attracted the attention of scientist and politicians on C sequestration as an effective strategy to tackle greenhouse gas (GHG) emissions. It has been estimated that the potential for C storage in world cropland is relevant (about 0.6-1.2PgCy(-1)). However, there are several constraints of C sequestration that raise concern about its effectiveness as a strategy to offset climate change. C sequestration is finite in quantity and time, reversible, and can be further decreased by socio-economic restrictions. Given these limitations, C sequestration can play only a minor role in the reduction of emissions (2-5% of total GHG emission under the highest emission scenarios). Yet, C sequestration is still attractive for two main reasons: it is likely to be particularly effective in reducing atmospheric CO2 levels in the first 20-30yr of its implementation and presents ancillary benefits for environment and sustainability that make it a real win-win strategy. These beneficial implications are discussed in this paper with emphasis on the need of C sequestration not only to offset climatic changes, but also for the equilibria of the environment and for the sustainability of agriculture and of entire human society.

  11. Potential of Agricultural By-product in Reducing Chlorpyrifos Leaching Through Soil

    NASA Astrophysics Data System (ADS)

    Romyen, Siraprapa; Luepromchai, Ekawan; Hawker, Darryl; Karnchanasest, Benjalak

    This study was conducted to determine the minimization of chlorpyrifos, an organophosphate pesticide, in leachate after spraying onto plants by agricultural by-product. Agricultural by-product samples including coconut husk, peat moss, rice husk and peanut shell were investigated in comparison to a sandy soil sample taken from orange grove. Batch partitioning experiments were initially conducted to evaluate sorption capacity of these sorbents. The experiments revealed that peat moss could sorp chlorpyrifos higher than coconut husk, rice husk and peanut shell, respectively. For soil, sorption obviously gave lower values than all agricultural-by product samples. Sorption coefficient (KD) values were increased with increasing organic carbon contents in sorbent, which indicated that organic carbon played an important role in sorption of chlorpyrifos. Half-life (t1/2) of chlorpyrifos in coconut husk was 8.6 days, which was reported to be the fastest among the tested biomass, whereas; its half-life was 56.8 days in soil. The results suggested that the sorped chlopyrifos could be degraded afterward. To find the optimum depth before use in the field, leaching experiments were carried out by packing 2, 3 and 4 cm coconut husk in columns and sprayed with 0.25 kg haG1 chlorpyrifos to the column surface. Results indicated that 97.02, 99.62 and 99.96% of chlorpyrifos mass could be retained in coconut husk at 2, 3 and 4 cm depth, respectively. Therefore, coconut husk was recommended as sorbent material due to the combination of high sorption capacity and enhanced biodegradation properties.

  12. Practical improvements in soil redox potential (Eh) measurement for characterisation of soil properties. Application for comparison of conventional and conservation agriculture cropping systems.

    PubMed

    Husson, Olivier; Husson, Benoit; Brunet, Alexandre; Babre, Daniel; Alary, Karine; Sarthou, Jean-Pierre; Charpentier, Hubert; Durand, Michel; Benada, Jaroslav; Henry, Marc

    2016-02-01

    The soil redox potential (Eh) can provide essential information to characterise soil conditions. In practice, however, numerous problems may arise regarding: (i) Eh determination in soils, especially aerobic soils, e.g. variations in the instrumentation and methodology for Eh measurement, high spatial and temporal Eh variability in soils, irreversibility of the redox reaction at the surface electrode, chemical disequilibrium; and (ii) measurement interpretation. This study aimed at developing a standardised method for redox potential measurement in soils, in order to use Eh as a soil quality indicator. This paper presents practical improvements in soil Eh measurement, especially regarding the control of electromagnetic perturbations, electrode choice and preparation, soil sample preparation (drying procedure) and soil:water extraction rate. The repeatability and reproducibility of the measurement method developed are highlighted. The use of Eh corrected at pH7, pe+pH or rH2, which are equivalent notions, is proposed to facilitate interpretation of the results. The application of this Eh measurement method allows characterisation of soil conditions with sufficient repeatability, reproducibility and accuracy to demonstrate that conservation agriculture systems positively alter the protonic and electronic balance of soil as compared to conventional systems.

  13. Practical improvements in soil redox potential (Eh) measurement for characterisation of soil properties. Application for comparison of conventional and conservation agriculture cropping systems.

    PubMed

    Husson, Olivier; Husson, Benoit; Brunet, Alexandre; Babre, Daniel; Alary, Karine; Sarthou, Jean-Pierre; Charpentier, Hubert; Durand, Michel; Benada, Jaroslav; Henry, Marc

    2016-02-01

    The soil redox potential (Eh) can provide essential information to characterise soil conditions. In practice, however, numerous problems may arise regarding: (i) Eh determination in soils, especially aerobic soils, e.g. variations in the instrumentation and methodology for Eh measurement, high spatial and temporal Eh variability in soils, irreversibility of the redox reaction at the surface electrode, chemical disequilibrium; and (ii) measurement interpretation. This study aimed at developing a standardised method for redox potential measurement in soils, in order to use Eh as a soil quality indicator. This paper presents practical improvements in soil Eh measurement, especially regarding the control of electromagnetic perturbations, electrode choice and preparation, soil sample preparation (drying procedure) and soil:water extraction rate. The repeatability and reproducibility of the measurement method developed are highlighted. The use of Eh corrected at pH7, pe+pH or rH2, which are equivalent notions, is proposed to facilitate interpretation of the results. The application of this Eh measurement method allows characterisation of soil conditions with sufficient repeatability, reproducibility and accuracy to demonstrate that conservation agriculture systems positively alter the protonic and electronic balance of soil as compared to conventional systems. PMID:26772129

  14. Contamination of Phthalate Esters (PAEs) in Typical Wastewater-Irrigated Agricultural Soils in Hebei, North China

    PubMed Central

    Zhang, Yuan; Liang, Qiong; Gao, Rutai; Hou, Haobo; Tan, Wenbing; He, Xiaosong; Zhang, Hui; Yu, Minda; Ma, Lina; Xi, Beidou; Wang, Xiaowei

    2015-01-01

    The Wangyang River (WYR) basin is a typical wastewater irrigation area in Hebei Province, North China. This study investigated the concentration and distribution of six priority phthalate esters (PAEs) in the agricultural soils in this area. Thirty-nine soil samples (0–20 cm) were collected along the WYR to assess the PAE residues in soils. Results showed that PAEs are ubiquitous environmental contaminants in the topsoil obtained from the irrigation area. The concentrations of Σ6PAEs range from 0.191 μg g−1 dw to 0.457 μg g−1 dw with an average value of 0.294 μg g−1 dw. Di(2-ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DnBP) are the dominant PAE species in the agricultural soils. Among the DEHP concentrations, the highest DEHP concentration was found at the sites close to the villages; this result suggested that dense anthropogenic activities and random garbage disposal in the rural area are possible sources of PAEs. The PAE concentrations were weakly and positively correlated with soil organic carbon and soil enzyme activities; thus, these factors can affect the distribution of PAEs. This study further showed that only dimethyl phthalate (DMP) concentrations exceeded the recommended allowable concentrations; no remediation measures are necessary to control the PAEs in the WYR area. However, the PAEs in the topsoil may pose a potential risk to the ecosystem and human health in this area. Therefore, the exacerbating PAE pollution should be addressed. PMID:26360905

  15. Phosphorus adsorption and desorption potential of stream sediments and field soils in agricultural watersheds.

    PubMed

    Agudelo, Sandra C; Nelson, Nathan O; Barnes, Philip L; Keane, Timothy D; Pierzynski, Gary M

    2011-01-01

    Phosphorus release from stream sediments into water could increase P loads leaving agricultural watersheds and contribute to lag-time between implementation of best management practices and improvement in water quality. Improved understanding of P release from stream sediments can assist in setting water quality goals and designing stream monitoring programs. The objective of this study was to estimate the relative potential of sediments and soils to release P to stream water in two agricultural watersheds. Stream sediments were collected from banks, pools, riffles, and depositional features. Soils were sampled from wheat, row crop, pasture, and manure-amended fields. Sediments and soils were analyzed for equilibrium P concentration at zero net P sorption (EPC0), maximum P adsorption capacity (P(max)), anion exchange extractable P (P(lab)), and degree of P saturation. Dissolved reactive P (DRP) of stream water was monitored. Stream sediment EPC0 was similar to or less than EPC0 from field soils; however, P(lab) of stream sediments was three times less than field soils. Sediments were sandy and had low P(max) due to low oxalate-extractable Fe and Al, which could be explained by stream geomorphology. Manure-amended fields had the highest EPC0 and P(lab) due to continued inputs of manure-based P; however, conventionally fertilized fields also represented an important P source due to their vast extent. Stream water DRP was similar to EPC0 of sediments during base flow and similar to EPC0 of field soils during storm flow. These results indicate that sediments in these streams are a relatively minor P source. PMID:21488503

  16. Contamination of Phthalate Esters (PAEs) in Typical Wastewater-Irrigated Agricultural Soils in Hebei, North China.

    PubMed

    Zhang, Yuan; Liang, Qiong; Gao, Rutai; Hou, Haobo; Tan, Wenbing; He, Xiaosong; Zhang, Hui; Yu, Minda; Ma, Lina; Xi, Beidou; Wang, Xiaowei

    2015-01-01

    The Wangyang River (WYR) basin is a typical wastewater irrigation area in Hebei Province, North China. This study investigated the concentration and distribution of six priority phthalate esters (PAEs) in the agricultural soils in this area. Thirty-nine soil samples (0-20 cm) were collected along the WYR to assess the PAE residues in soils. Results showed that PAEs are ubiquitous environmental contaminants in the topsoil obtained from the irrigation area. The concentrations of Σ6PAEs range from 0.191 μg g-1 dw to 0.457 μg g-1 dw with an average value of 0.294 μg g-1 dw. Di(2-ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DnBP) are the dominant PAE species in the agricultural soils. Among the DEHP concentrations, the highest DEHP concentration was found at the sites close to the villages; this result suggested that dense anthropogenic activities and random garbage disposal in the rural area are possible sources of PAEs. The PAE concentrations were weakly and positively correlated with soil organic carbon and soil enzyme activities; thus, these factors can affect the distribution of PAEs. This study further showed that only dimethyl phthalate (DMP) concentrations exceeded the recommended allowable concentrations; no remediation measures are necessary to control the PAEs in the WYR area. However, the PAEs in the topsoil may pose a potential risk to the ecosystem and human health in this area. Therefore, the exacerbating PAE pollution should be addressed. PMID:26360905

  17. Interdependence of soil and agricultural practice in a two - year phytoremediation in situ experiment

    NASA Astrophysics Data System (ADS)

    Nwaichi, Eucharia; Onyeike, Eugene; Frac, Magdalena; Iwo, Godknows

    2016-04-01

    A two - year plant - based soil clean - up was carried out at a crude oil spill agricultural site in a Niger Delta community in Nigeria to access further clean - up potentials of Cymbopogon citratus. Applied diagnostic ratios identified mixed petrogenic and pyrogenic sources as the main contributors of PAHs. Up to 90.8% sequestration was obtained for carcinogenic PAHs especially Benz (a) pyrene in a 2 - phase manner. A community level approach for assessing patterns of sole carbon source utilization by mixed microbial samples was employed to differentiate spatial and temporal changes in the soil microbial communities. In relation to pollution, soil conditioning notably decreased the lag times and showed mixed effects for colour development rates, maximum absorbance and the overall community pattern. For rate and utilization of different carbon substrates in BIOLOG wells, after day 3, in comparison to control soil communities, contamination with hydrocarbons and associated types increased amines and amides consumption. Consumption of carbohydrates in all polluted and unamended regimes decreased markedlyin comparison to those cultivated with C. citratus. We found a direct relationship between cellulose breakdown, measurable with B-glucosidase activity, organic matter content and CO2 realease within all soils in the present study. Organic amendment rendered most studied contaminants unavailable for uptake in preference to inorganic fertilizer in both study years. Generally, phytoremediation improved significantly the microbial community activity and thus would promote ecosystem restoration in relation to most patronised techniques. Supplementation with required nutrients, in a long - term design would present many ecological benefits. Keywords: Agricultural soils; Recovery; Hydrocarbon pollution; Ecology; Management practice.

  18. Decision support tool for soil sampling of heterogeneous pesticide (chlordecone) pollution.

    PubMed

    Clostre, Florence; Lesueur-Jannoyer, Magalie; Achard, Raphaël; Letourmy, Philippe; Cabidoche, Yves-Marie; Cattan, Philippe

    2014-02-01

    When field pollution is heterogeneous due to localized pesticide application, as is the case of chlordecone (CLD), the mean level of pollution is difficult to assess. Our objective was to design a decision support tool to optimize soil sampling. We analyzed the CLD heterogeneity of soil content at 0-30- and 30-60-cm depth. This was done within and between nine plots (0.4 to 1.8 ha) on andosol and ferralsol. We determined that 20 pooled subsamples per plot were a satisfactory compromise with respect to both cost and accuracy. Globally, CLD content was greater for andosols and the upper soil horizon (0-30 cm). Soil organic carbon cannot account for CLD intra-field variability. Cropping systems and tillage practices influence the CLD content and distribution; that is CLD pollution was higher under intensive banana cropping systems and, while upper soil horizon was more polluted than the lower one with shallow tillage (<40 cm), deeper tillage led to a homogenization and a dilution of the pollution in the soil profile. The decision tool we proposed compiles and organizes these results to better assess CLD soil pollution in terms of sampling depth, distance, and unit at field scale. It accounts for sampling objectives, farming practices (cropping system, tillage), type of soil, and topographical characteristics (slope) to design a relevant sampling plan. This decision support tool is also adaptable to other types of heterogeneous agricultural pollution at field level.

  19. Can conservation trump impacts of climate change and extremes on soil erosion in agricultural landscapes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Preservation of top soil is critical for the long term sustainability of agricultural productivity, food security, and biodiversity. However, today’s growing population and increasing demand for food and fiber is stressing the agricultural soil and water resources. Climate change imposes additional ...

  20. Assessment of heavy metal and pesticide levels in soil and plant products from agricultural area of Belgrade, Serbia.

    PubMed

    Marković, Mirjana; Cupać, Svjetlana; Durović, Rada; Milinović, Jelena; Kljajić, Petar

    2010-02-01

    This study was aimed to assess the levels of selected heavy metals and pesticides in soil and plant products from an agricultural area of Belgrade, Serbia and to indicate possible sources and risks of contamination. Soil, vegetable, and fruit samples from the most important agricultural city areas were collected from July to November of 2006. Metal contents were determined by atomic absorption spectrometry, whereas pesticide residues were analyzed by gas chromatography-mass spectrometry after extraction performed using solid-phase microextraction technique. Soil characterization based on the determination of selected physical and chemical properties revealed heterogeneous soils belonging to different soil groups. The concentrations of lead, cadmium, copper, and zinc in soil samples do not exceed the limits established by national and international regulations. Residues of the herbicide atrazine were detected in three soil samples, with levels lower than the relevant limit. The presence of other herbicides, namely prometryn, chloridazon, acetochlor, flurochloridone, and napropamide, was registered in some soil samples as well. Among the insecticides investigated in the soil, fenitrothion and chlorpyrifos were the only ones detected. In most of the investigated vegetable samples from the Obrenovac area, Pb and Cd contents are higher in comparison with the maximum levels, indicating the emission of coal combustion products from local thermal power plants as a possible source of contamination. Residue levels of some herbicides and insecticides (metribuzin, trifluralin, pendimethalin, bifenthrin, chlorpyrifos, and cypermethrin) determined in tomato, pepper, potato, and onion samples from Slanci, Ovca, and Obrenovac areas are even several times higher than the maximum residue levels. Inappropriate use of these plant protection products is considered to be the most probable reason of contamination. Because increased levels of heavy metals and pesticide residues found in

  1. Assessment of heavy metal and pesticide levels in soil and plant products from agricultural area of Belgrade, Serbia.

    PubMed

    Marković, Mirjana; Cupać, Svjetlana; Durović, Rada; Milinović, Jelena; Kljajić, Petar

    2010-02-01

    This study was aimed to assess the levels of selected heavy metals and pesticides in soil and plant products from an agricultural area of Belgrade, Serbia and to indicate possible sources and risks of contamination. Soil, vegetable, and fruit samples from the most important agricultural city areas were collected from July to November of 2006. Metal contents were determined by atomic absorption spectrometry, whereas pesticide residues were analyzed by gas chromatography-mass spectrometry after extraction performed using solid-phase microextraction technique. Soil characterization based on the determination of selected physical and chemical properties revealed heterogeneous soils belonging to different soil groups. The concentrations of lead, cadmium, copper, and zinc in soil samples do not exceed the limits established by national and international regulations. Residues of the herbicide atrazine were detected in three soil samples, with levels lower than the relevant limit. The presence of other herbicides, namely prometryn, chloridazon, acetochlor, flurochloridone, and napropamide, was registered in some soil samples as well. Among the insecticides investigated in the soil, fenitrothion and chlorpyrifos were the only ones detected. In most of the investigated vegetable samples from the Obrenovac area, Pb and Cd contents are higher in comparison with the maximum levels, indicating the emission of coal combustion products from local thermal power plants as a possible source of contamination. Residue levels of some herbicides and insecticides (metribuzin, trifluralin, pendimethalin, bifenthrin, chlorpyrifos, and cypermethrin) determined in tomato, pepper, potato, and onion samples from Slanci, Ovca, and Obrenovac areas are even several times higher than the maximum residue levels. Inappropriate use of these plant protection products is considered to be the most probable reason of contamination. Because increased levels of heavy metals and pesticide residues found in

  2. The fate of organic carbon in colluvial soils in a subtropical agricultural catchment (Arvorezinha, Brazil)

    NASA Astrophysics Data System (ADS)

    Van de Broek, Marijn; Van Oost, Kristof; Minella, Jean; Govers, Gerard

    2016-04-01

    One of the main reasons as to why soil erosion is considered to be a carbon sink for the atmosphere is that eroded carbon is often redeposited and buried in depositional environments. However, the quantification of the magnitude of this effect is still uncertain because the residence time of soil organic carbon in depositional environments is ill defined. The latter is especially true for tropical and subtropical areas as field data for these climatic zones are largely lacking. This is an important hiatus as ca. 40% of the total global arable land is located in the (sub-)tropics [1]. We collected samples from four depositional and one stable agricultural profile in a small agricultural catchment in Arvorezinha (Brazil) where deforestation started ca. 90 yrs ago. δ13C depth profiles allowed to identify the bottom of the original A-horizon: this is because δ13C values of the buried forest soils are significantly heavier than those of the colluvial deposits. The results show that soil organic carbon contents systematically decrease with depth below the actual plough layer. This is due to the fact that a significant fraction of the organic carbon that was originally deposited is removed by mineralization from these soils over decadal time scales. As the time of deforestation is known, age-depth curves could be established. Combining this information with SOC measurements allowed for a first estimate of carbon preservation rates and showed that after 70 years ca. 25% of the deposited organic carbon is released to the atmosphere: results were very consistent across profiles. In temperate environments, the time necessary for this fraction of the deposited carbon to be mineralized is somewhat longer, i.e. 100 years [2]. This suggests that soil organic carbon may be decomposed faster in sub-tropical environments in comparison to temperate environments. This is not unexpected, given the fact that average soil temperatures are higher and soils are, in this climate

  3. Unexpected stimulation of soil methane uptake as emergent property of agricultural soils following bio-based residue application.

    PubMed

    Ho, Adrian; Reim, Andreas; Kim, Sang Yoon; Meima-Franke, Marion; Termorshuizen, Aad; de Boer, Wietse; van der Putten, Wim H; Bodelier, Paul L E

    2015-10-01

    Intensification of agriculture to meet the global food, feed, and bioenergy demand entail increasing re-investment of carbon compounds (residues) into agro-systems to prevent decline of soil quality and fertility. However, agricultural intensification decreases soil methane uptake, reducing, and even causing the loss of the methane sink function. In contrast to wetland agricultural soils (rice paddies), the methanotrophic potential in well-aerated agricultural soils have received little attention, presumably due to the anticipated low or negligible methane uptake capacity in these soils. Consequently, a detailed study verifying or refuting this assumption is still lacking. Exemplifying a typical agricultural practice, we determined the impact of bio-based residue application on soil methane flux, and determined the methanotrophic potential, including a qualitative (diagnostic microarray) and quantitative (group-specific qPCR assays) analysis of the methanotrophic community after residue amendments over 2 months. Unexpectedly, after amendments with specific residues, we detected a significant transient stimulation of methane uptake confirmed by both the methane flux measurements and methane oxidation assay. This stimulation was apparently a result of induced cell-specific activity, rather than growth of the methanotroph population. Although transient, the heightened methane uptake offsets up to 16% of total gaseous CO2 emitted during the incubation. The methanotrophic community, predominantly comprised of Methylosinus may facilitate methane oxidation in the agricultural soils. While agricultural soils are generally regarded as a net methane source or a relatively weak methane sink, our results show that methane oxidation rate can be stimulated, leading to higher soil methane uptake. Hence, even if agriculture exerts an adverse impact on soil methane uptake, implementing carefully designed management strategies (e.g. repeated application of specific residues) may

  4. Unexpected stimulation of soil methane uptake as emergent property of agricultural soils following bio-based residue application.

    PubMed

    Ho, Adrian; Reim, Andreas; Kim, Sang Yoon; Meima-Franke, Marion; Termorshuizen, Aad; de Boer, Wietse; van der Putten, Wim H; Bodelier, Paul L E

    2015-10-01

    Intensification of agriculture to meet the global food, feed, and bioenergy demand entail increasing re-investment of carbon compounds (residues) into agro-systems to prevent decline of soil quality and fertility. However, agricultural intensification decreases soil methane uptake, reducing, and even causing the loss of the methane sink function. In contrast to wetland agricultural soils (rice paddies), the methanotrophic potential in well-aerated agricultural soils have received little attention, presumably due to the anticipated low or negligible methane uptake capacity in these soils. Consequently, a detailed study verifying or refuting this assumption is still lacking. Exemplifying a typical agricultural practice, we determined the impact of bio-based residue application on soil methane flux, and determined the methanotrophic potential, including a qualitative (diagnostic microarray) and quantitative (group-specific qPCR assays) analysis of the methanotrophic community after residue amendments over 2 months. Unexpectedly, after amendments with specific residues, we detected a significant transient stimulation of methane uptake confirmed by both the methane flux measurements and methane oxidation assay. This stimulation was apparently a result of induced cell-specific activity, rather than growth of the methanotroph population. Although transient, the heightened methane uptake offsets up to 16% of total gaseous CO2 emitted during the incubation. The methanotrophic community, predominantly comprised of Methylosinus may facilitate methane oxidation in the agricultural soils. While agricultural soils are generally regarded as a net methane source or a relatively weak methane sink, our results show that methane oxidation rate can be stimulated, leading to higher soil methane uptake. Hence, even if agriculture exerts an adverse impact on soil methane uptake, implementing carefully designed management strategies (e.g. repeated application of specific residues) may

  5. Phthalate esters contamination in soil and plants on agricultural land near an electronic waste recycling site.

    PubMed

    Ma, Ting Ting; Christie, Peter; Luo, Yong Ming; Teng, Ying

    2013-08-01

    The accumulation of phthalic acid esters (PAEs) in soil and plants in agricultural land near an electronic waste recycling site in east China has become a great threat to the neighboring environmental quality and human health. Soil and plant samples collected from land under different utilization, including fallow plots, vegetable plots, plots with alfalfa (Medicago sativa L.) as green manure, fallow plots under long-term flooding and fallow plots under alternating wet and dry periods, together with plant samples from relative plots were analyzed for six PAE compounds nominated as prior pollutants by USEPA. In the determined samples, the concentrations of six target PAE pollutants ranged from 0.31-2.39 mg/kg in soil to 1.81-5.77 mg/kg in various plants (dry weight/DW), and their bioconcentration factors (BCFs) ranged from 5.8 to 17.9. Health risk assessments were conducted on target PAEs, known as typical environmental estrogen analogs, based on their accumulation in the edible parts of vegetables. Preliminary risk assessment to human health from soil and daily vegetable intake indicated that DEHP may present a high-exposure risk on all ages of the population in the area by soil ingestion or vegetable consumption. The potential damage that the target PAE compounds may pose to human health should be taken into account in further comprehensive risk assessments in e-waste recycling sites areas. Moreover, alfalfa removed substantial amounts of PAEs from the soil, and its use can be considered a good strategy for in situ remediation of PAEs.

  6. Topography Mediates the Influence of Cover Crops on Soil Nitrate Levels in Row Crop Agricultural Systems.

    PubMed

    Ladoni, Moslem; Kravchenko, Alexandra N; Robertson, G Phillip

    2015-01-01

    Supplying adequate amounts of soil N for plant growth during the growing season and across large agricultural fields is a challenge for conservational agricultural systems with cover crops. Knowledge about cover crop effects on N comes mostly from small, flat research plots and performance of cover crops across topographically diverse agricultural land is poorly understood. Our objective was to assess effects of both leguminous (red clover) and non-leguminous (winter rye) cover crops on potentially mineralizable N (PMN) and [Formula: see text] levels across a topographically diverse landscape. We studied conventional, low-input, and organic managements in corn-soybean-wheat rotation. The rotations of low-input and organic managements included rye and red clover cover crops. The managements were implemented in twenty large undulating fields in Southwest Michigan starting from 2006. The data collection and analysis were conducted during three growing seasons of 2011, 2012 and 2013. Observational micro-plots with and without cover crops were laid within each field on three contrasting topographical positions of depression, slope and summit. Soil samples were collected 4-5 times during each growing season and analyzed for [Formula: see text] and PMN. The results showed that all three managements were similar in their temporal and spatial distributions of NO3-N. Red clover cover crop increased [Formula: see text] by 35% on depression, 20% on slope and 32% on summit positions. Rye cover crop had a significant 15% negative effect on [Formula: see text] in topographical depressions but not in slope and summit positions. The magnitude of the cover crop effects on soil mineral nitrogen across topographically diverse fields was associated with the amount of cover crop growth and residue production. The results emphasize the potential environmental and economic benefits that can be generated by implementing site-specific topography-driven cover crop management in row

  7. Topography Mediates the Influence of Cover Crops on Soil Nitrate Levels in Row Crop Agricultural Systems.

    PubMed

    Ladoni, Moslem; Kravchenko, Alexandra N; Robertson, G Phillip

    2015-01-01

    Supplying adequate amounts of soil N for plant growth during the growing season and across large agricultural fields is a challenge for conservational agricultural systems with cover crops. Knowledge about cover crop effects on N comes mostly from small, flat research plots and performance of cover crops across topographically diverse agricultural land is poorly understood. Our objective was to assess effects of both leguminous (red clover) and non-leguminous (winter rye) cover crops on potentially mineralizable N (PMN) and [Formula: see text] levels across a topographically diverse landscape. We studied conventional, low-input, and organic managements in corn-soybean-wheat rotation. The rotations of low-input and organic managements included rye and red clover cover crops. The managements were implemented in twenty large undulating fields in Southwest Michigan starting from 2006. The data collection and analysis were conducted during three growing seasons of 2011, 2012 and 2013. Observational micro-plots with and without cover crops were laid within each field on three contrasting topographical positions of depression, slope and summit. Soil samples were collected 4-5 times during each growing season and analyzed for [Formula: see text] and PMN. The results showed that all three managements were similar in their temporal and spatial distributions of NO3-N. Red clover cover crop increased [Formula: see text] by 35% on depression, 20% on slope and 32% on summit positions. Rye cover crop had a significant 15% negative effect on [Formula: see text] in topographical depressions but not in slope and summit positions. The magnitude of the cover crop effects on soil mineral nitrogen across topographically diverse fields was associated with the amount of cover crop growth and residue production. The results emphasize the potential environmental and economic benefits that can be generated by implementing site-specific topography-driven cover crop management in row

  8. Topography Mediates the Influence of Cover Crops on Soil Nitrate Levels in Row Crop Agricultural Systems

    PubMed Central

    Ladoni, Moslem; Kravchenko, Alexandra N.; Robertson, G. Phillip

    2015-01-01

    Supplying adequate amounts of soil N for plant growth during the growing season and across large agricultural fields is a challenge for conservational agricultural systems with cover crops. Knowledge about cover crop effects on N comes mostly from small, flat research plots and performance of cover crops across topographically diverse agricultural land is poorly understood. Our objective was to assess effects of both leguminous (red clover) and non-leguminous (winter rye) cover crops on potentially mineralizable N (PMN) and NO3--N levels across a topographically diverse landscape. We studied conventional, low-input, and organic managements in corn-soybean-wheat rotation. The rotations of low-input and organic managements included rye and red clover cover crops. The managements were implemented in twenty large undulating fields in Southwest Michigan starting from 2006. The data collection and analysis were conducted during three growing seasons of 2011, 2012 and 2013. Observational micro-plots with and without cover crops were laid within each field on three contrasting topographical positions of depression, slope and summit. Soil samples were collected 4–5 times during each growing season and analyzed for NO3--N and PMN. The results showed that all three managements were similar in their temporal and spatial distributions of NO3—N. Red clover cover crop increased NO3--N by 35% on depression, 20% on slope and 32% on summit positions. Rye cover crop had a significant 15% negative effect on NO3--N in topographical depressions but not in slope and summit positions. The magnitude of the cover crop effects on soil mineral nitrogen across topographically diverse fields was associated with the amount of cover crop growth and residue production. The results emphasize the potential environmental and economic benefits that can be generated by implementing site-specific topography-driven cover crop management in row-crop agricultural systems. PMID:26600462

  9. Microbial Profiling of a Suppressiveness-Induced Agricultural Soil Amended with Composted Almond Shells.

    PubMed

    Vida, Carmen; Bonilla, Nuria; de Vicente, Antonio; Cazorla, Francisco M

    2016-01-01

    This study focused on the microbial profile present in an agricultural soil that becomes suppressive after the application of composted almond shells (AS) as organic amendments. For this purpose, we analyzed the functions and composition of the complex communities present in an experimental orchard of 40-year-old avocado trees, many of them historically amended with composted almond shells. The role of microbes in the suppression of Rosellinia necatrix, the causative agent of avocado white root rot, was determined after heat-treatment and complementation experiments with different types of soil. Bacterial and fungal profiles obtained from natural soil samples based on the 16S rRNA gene and ITS sequencing revealed slight differences among the amended (AS) and unamended (CT) soils. When the soil was under the influence of composted almond shells as organic amendments, an increase in Proteobacteria and Ascomycota groups was observed, as well as a reduction in Acidobacteria and Mortierellales. Complementary to these findings, functional analysis by GeoChip 4.6 confirmed these subtle differences, mainly present in the relative abundance of genes involved in the carbon cycle. Interestingly, a group of specific probes included in the "soil benefit" category was present only in AS-amended soils, corresponding to specific microorganisms previously described as potential biocontrol agents, such as Pseudomonas spp., Burkholderia spp., or Actinobacteria. Considering the results of both analyses, we determined that AS-amendments to the soil led to an increase in some orders of Gammaproteobacteria, Betaproteobacteria, and Dothideomycetes, as well as a reduction in the abundance of Xylariales fungi (where R. necatrix is allocated). The combination of microbial action and substrate properties of suppressiveness are discussed. PMID:26834725

  10. Microbial Profiling of a Suppressiveness-Induced Agricultural Soil Amended with Composted Almond Shells

    PubMed Central

    Vida, Carmen; Bonilla, Nuria; de Vicente, Antonio; Cazorla, Francisco M.

    2016-01-01

    This study focused on the microbial profile present in an agricultural soil that becomes suppressive after the application of composted almond shells (AS) as organic amendments. For this purpose, we analyzed the functions and composition of the complex communities present in an experimental orchard of 40-year-old avocado trees, many of them historically amended with composted almond shells. The role of microbes in the suppression of Rosellinia necatrix, the causative agent of avocado white root rot, was determined after heat-treatment and complementation experiments with different types of soil. Bacterial and fungal profiles obtained from natural soil samples based on the 16S rRNA gene and ITS sequencing revealed slight differences among the amended (AS) and unamended (CT) soils. When the soil was under the influence of composted almond shells as organic amendments, an increase in Proteobacteria and Ascomycota groups was observed, as well as a reduction in Acidobacteria and Mortierellales. Complementary to these findings, functional analysis by GeoChip 4.6 confirmed these subtle differences, mainly present in the relative abundance of genes involved in the carbon cycle. Interestingly, a group of specific probes included in the “soil benefit” category was present only in AS-amended soils, corresponding to specific microorganisms previously described as potential biocontrol agents, such as Pseudomonas spp., Burkholderia spp., or Actinobacteria. Considering the results of both analyses, we determined that AS-amendments to the soil led to an increase in some orders of Gammaproteobacteria, Betaproteobacteria, and Dothideomycetes, as well as a reduction in the abundance of Xylariales fungi (where R. necatrix is allocated). The combination of microbial action and substrate properties of suppressiveness are discussed. PMID:26834725

  11. Economic Potential of Greenhouse Gas Emission Reductions: Comparative Role for Soil Sequestration in Agriculture and Forestry

    SciTech Connect

    Mccarl, Bruce A.; Schneider, Uwe; Murray, Brian; Williams, Jimmy; Sands, Ronald D.

    2001-05-14

    This paper examines the relative contribution of agricultural and forestry activities in an emission reduction program, focusing in part on the relative desirability of sequestration in forests and agricultural soils. The analysis considers the effects of competition for land and other resources between agricultural activities, forestry activities and traditional production. In addition, the paper examines the influence of saturation and volatility.

  12. Effect of plastic mulching on mycotoxin occurrence and mycobiome abundance in soil samples from asparagus crops.

    PubMed

    Muñoz, K; Schmidt-Heydt, M; Stoll, D; Diehl, D; Ziegler, J; Geisen, R; Schaumann, G E

    2015-11-01

    Plastic mulching (PM) is widely used in modern agriculture because of its advantageous effects on soil temperature and water conservation, factors which strongly influence the microbiology of the soil. The aim of this study was to assess the effect of PM on mycotoxin occurrence in relation with mycobiome abundance/diversity and soil physicochemical properties. Soil samples were collected from green (GA) and white asparagus (WA) crops, the last under PM. Both crops were cultivated in a ridge-furrow-ridge system without irrigation. Samples were analyzed for mycotoxin occurrence via liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS). Total colony-forming unit was indicative of mycobiome abundance, and analysis of mycobiome diversity was performed by internal transcribed spacer (ITS) sequencing. PM avoided the drop of soil temperature in winter and allowed higher soil temperature in early spring compared to non-covered soil. Moreover, the use of PM provided controlled conditions for water content in soil. This was enough to generate a dissimilar mycotoxin occurrence and mycobiome diversity/abundance in covered and non-covered soil. Mycotoxin soil contamination was confirmed for deoxynivalenol (DON), range LOD to 32.1 ng/g (LOD = 1.1 ng/g). The DON values were higher under PM (average 16.9 ± 10.1 ng/g) than in non-covered soil (9.1 ± 7.9 ng/g); however, this difference was not statically significant (p = 0.09). Mycobiome analysis showed a fungal compartment up to fivefold higher in soil under PM compared to GA. The diversity of the mycobiome varied between crops and also along the soil column, with an important dominance of Fusarium species at the root zone in covered soils.

  13. Effect of plastic mulching on mycotoxin occurrence and mycobiome abundance in soil samples from asparagus crops.

    PubMed

    Muñoz, K; Schmidt-Heydt, M; Stoll, D; Diehl, D; Ziegler, J; Geisen, R; Schaumann, G E

    2015-11-01

    Plastic mulching (PM) is widely used in modern agriculture because of its advantageous effects on soil temperature and water conservation, factors which strongly influence the microbiology of the soil. The aim of this study was to assess the effect of PM on mycotoxin occurrence in relation with mycobiome abundance/diversity and soil physicochemical properties. Soil samples were collected from green (GA) and white asparagus (WA) crops, the last under PM. Both crops were cultivated in a ridge-furrow-ridge system without irrigation. Samples were analyzed for mycotoxin occurrence via liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS). Total colony-forming unit was indicative of mycobiome abundance, and analysis of mycobiome diversity was performed by internal transcribed spacer (ITS) sequencing. PM avoided the drop of soil temperature in winter and allowed higher soil temperature in early spring compared to non-covered soil. Moreover, the use of PM provided controlled conditions for water content in soil. This was enough to generate a dissimilar mycotoxin occurrence and mycobiome diversity/abundance in covered and non-covered soil. Mycotoxin soil contamination was confirmed for deoxynivalenol (DON), range LOD to 32.1 ng/g (LOD = 1.1 ng/g). The DON values were higher under PM (average 16.9 ± 10.1 ng/g) than in non-covered soil (9.1 ± 7.9 ng/g); however, this difference was not statically significant (p = 0.09). Mycobiome analysis showed a fungal compartment up to fivefold higher in soil under PM compared to GA. The diversity of the mycobiome varied between crops and also along the soil column, with an important dominance of Fusarium species at the root zone in covered soils. PMID:26412448

  14. Non-growing season nitrous oxide fluxes from agricultural soils

    NASA Astrophysics Data System (ADS)

    Kariyapperuma Athukoralage, Kumudinie

    A two-year field experiment was conducted at the Arkell Research Station, Ontario, Canada to evaluate composting as a mitigation strategy for greenhouse gases (GHGs). The objectives were to quantify and compare non-growing season nitrous oxide (N2O) fluxes from agricultural soils after fall manure application of composted and untreated liquid swine manure. Nitrous oxide fluxes were measured using a micrometeorological method. Compared to untreated liquid swine manure (LSM), composted swine manure (CSM) resulted in 57% reduction of soil N2O emissions during February to April in 2005, but emissions during the same period in 2006 were not affected by treatments. This effect was related to fall and winter weather conditions with the significant reduction occurring in the year when soil freezing was more pronounced. The DNDC (DeNitrification-DeComposition) model was tested against data measured during the non-growing seasons from 2000 to 2004, for farming with conventional management at the Elora Research Station, Ontario, Canada. The objective was to assess the ability of the DNDC model to simulate non-growing season N2O fluxes from soils in southwestern Ontario. Comparison between model-simulated and measured data indicated that background fluxes were relatively well predicted. The spring thaw N2O flux event was correctly timed by the DNDC model, but was smaller than the measured spring thaw event. Though there was no N2O emission event measured in early May, the DNDC model predicted a large event, simultaneous with the physical release of predicted ice-trapped N2O. Removing the large and late predicted emission peak and increasing the contribution of newly produced N2O due to denitrification to the early spring thaw event were proposed. Three data sets from studies conducted in Ontario, Canada were used to estimate and compare the overall GHG (N2O and methane) emissions from LSM and CSM. Compared to LSM storage, the composting process reduced GHG emissions by 35% (CO

  15. Ammonia- and methane-oxidizing microorganisms in high-altitude wetland sediments and adjacent agricultural soils.

    PubMed

    Yang, Yuyin; Shan, Jingwen; Zhang, Jingxu; Zhang, Xiaoling; Xie, Shuguang; Liu, Yong

    2014-12-01

    Ammonia oxidation is known to be carried out by ammonia-oxidizing bacteria (AOB) and archaea (AOA), while methanotrophs (methane-oxidizing bacteria (MOB)) play an important role in mitigating methane emissions from the environment. However, the difference of AOA, AOB, and MOB distribution in wetland sediment and adjacent upland soil remains unclear. The present study investigated the abundances and community structures of AOA, AOB, and MOB in sediments of a high-altitude freshwater wetland in Yunnan Province (China) and adjacent agricultural soils. Variations of AOA, AOB, and MOB community sizes and structures were found in water lily-vegetated and Acorus calamus-vegetated sediments and agricultural soils (unflooded rice soil, cabbage soil, and garlic soil and flooded rice soil). AOB community size was higher than AOA in agricultural soils and lily-vegetated sediment, but lower in A. calamus-vegetated sediment. MOB showed a much higher abundance than AOA and AOB. Flooded rice soil had the largest AOA, AOB, and MOB community sizes. Principal coordinate analyses and Jackknife Environment Clusters analyses suggested that unflooded and flooded rice soils had relatively similar AOA, AOB, and MOB structures. Cabbage soil and A. calamus-vegetated sediment had relatively similar AOA and AOB structures, but their MOB structures showed a large difference. Nitrososphaera-like microorganisms were the predominant AOA species in garlic soil but were present with a low abundance in unflooded rice soil and cabbage soil. Nitrosospira-like AOB were dominant in wetland sediments and agricultural soils. Type I MOB Methylocaldum and type II MOB Methylocystis were dominant in wetland sediments and agricultural soils. Moreover, Pearson's correlation analysis indicated that AOA Shannon diversity was positively correlated with the ratio of organic carbon to nitrogen (p < 0.05). This work could provide some new insights toward ammonia and methane oxidation in soil and wetland sediment

  16. Impact of PAH on biological health parameters of soils of an Indian refinery and adjoining agricultural area--a case study.

    PubMed

    Chaudhary, Priyanka; Singh, Shashi Bala; Chaudhry, Smita; Nain, Lata

    2012-01-01

    The present study is aimed at analysing and comparing different soil enzymes in soil samples of native contaminated sites of a Mathura refinery and adjoining agricultural land. Enzyme activities are considered as indicators of soil quality and changes in biogeochemical function due to management or perturbations. Soil samples were collected from the premises and nearby area of Mathura refinery, India. Biological health parameters (dehydrogenase, aryl esterase, aryl sulphatase, [Formula: see text]-glucosidase, alkaline phosphatase, acid phosphatase, lipase, laccase and catalase activity) were estimated in the soil samples. Among all the samples, sewage sludge soil showed maximum activity of enzymes, microbial biomass carbon and most probable number of polycyclic aromatic hydrocarbon (PAH) degraders in soils spiked with three- to four-ring PAHs at 50 ppm. Available phosphorus, potassium and nitrogen was also exceptionally high in this sample, indicating maximum microbial bioconversion due to presence of nutrients stimulating potent PAH-degrading microorganisms.

  17. Mapping Soil Organic Carbon Resources Across Agricultural Land Uses in Highland Lesotho Using High Resolution Satellite Imagery

    NASA Astrophysics Data System (ADS)

    Knight, J.; Adam, E.

    2015-12-01

    Mapping spatial patterns of soil organic carbon (SOC) using high resolution satellite imagery is especially important in inaccessible or upland areas that have limited field measurements, where land use and land cover (LULC) are changing rapidly, or where the land surface is sensitive to overgrazing and high rates of soil erosion and thus sediment, nutrient and carbon export. Here we outline the methods and results of mapping soil organic carbon in highland areas (~2400 m) of eastern Lesotho, southern Africa, across different land uses. Bedrock summit areas with very thin soils are dominated by xeric alpine grassland; terrace agriculture with strip fields and thicker soils is found within river valleys. Multispectral Worldview 2 imagery was used to map LULC across the region. An overall accuracy of 88% and kappa value of 0.83 were achieved using a support vector machine model. Soils were examined in the field from different LULC areas for properties such as soil depth, maturity and structure. In situ soils in the field were also evaluated using a portable analytical spectral device (ASD) in order to ground truth spectral signatures from Worldview. Soil samples were examined in the lab for chemical properties including organic carbon. Regression modeling was used in order to establish a relationship between soil characteristics and soil spectral reflectance. We were thus able to map SOC across this diverse landscape. Results show that there are notable differences in SOC between upland and agricultural areas which reflect both soil thickness and maturity, and land use practices such as manuring of fields by cattle. Soil erosion and thus carbon (nutrient) export is significant issue in this region, which this project will now be examining.

  18. Biodegradation of insecticide monocrotophos by Bacillus subtilis KPA-1, isolated from agriculture soils.

    PubMed

    Acharya, K P; Shilpkar, P; Shah, M C; Chellapandi, P

    2015-02-01

    Twenty bacterial strains, which are capable of degrading monocrotophos, were isolated from five soil samples collected from agriculture soils in India. The ability of the strains to mineralize monocrotophos was investigated under different culture conditions. A potential strain degrading monocrotophos was selected and named KPA-1. The strain was identified as a Bacillus subtilis on the basis of the results of its cellular morphology, physiological and chemotaxonomic characteristics, and phylogenetic conclusion of 16S ribosomal DNA (rDNA) gene sequences. Organophosphate hydrolase (opdA gene) involved in the initial biodegradation of monocrotophos in KPA-1 was quantitatively expressed, which was a constitutively expressed cytosolic enzyme. RT-qPCR data revealed that KPA-1 harboring opdA gene in an early stage was significantly downregulated from opdA gene in a degradation stage (1.5 fold more) with a p value of 0.0375 (p < 0.05). We have optimized culture conditions for the efficient degradation (94.2 %) of monocrotophos under aerobic conditions. Growth and degradation kinetic studies proved that KPA-1 was able to grow in minimal salt medium containing 1000 ppm monocrotophos as the only carbon source. Hence, KPA-1 culture has a great potential utility for the bioremediation of agriculture soils contaminated with organophosphorus pesticides, particularly monocrotophos.

  19. Hydrological controls on heterotrophic soil respiration across an agricultural landscape

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water availability is an important determinant of variation in soil respiration, but a consistent relationship between soil water and the relative flux rate of carbon dioxide across different soil types remains elusive. Using large undisturbed soil columns (N = 12), we evaluated soil water controls...

  20. Deep ploughing increases agricultural soil organic matter stocks.

    PubMed

    Alcántara, Viridiana; Don, Axel; Well, Reinhard; Nieder, Rolf

    2016-08-01

    Subsoils play an important role within the global C cycle, since they have high soil organic carbon (SOC) storage capacity due to generally low SOC concentrations. However, measures for enhancing SOC storage commonly focus on topsoils. This study assessed the long-term storage and stability of SOC in topsoils buried in arable subsoils by deep ploughing, a globally applied method for breaking up hard pans and improving soil structure to optimize crop growing conditions. One effect of deep ploughing is translocation of SOC formed near the surface into the subsoil, with concomitant mixing of SOC-poor subsoil material into the 'new' topsoil. Deep-ploughed croplands represent unique long-term in situ incubations of SOC-rich material in subsoils. In this study, we sampled five loamy and five sandy soils that were ploughed to 55-90 cm depth 35-50 years ago. Adjacent, similarly managed but conventionally ploughed subplots were sampled as reference. The deep-ploughed soils contained on average 42 ± 13% more SOC than the reference subplots. On average, 45 years after deep ploughing, the 'new' topsoil still contained 15% less SOC than the reference topsoil, indicating long-term SOC accumulation potential in the topsoil. In vitro incubation experiments on the buried sandy soils revealed 63 ± 6% lower potential SOC mineralisation rates and also 67 ± 2% lower SOC mineralisation per unit SOC in the buried topsoils than in the reference topsoils. Wider C/N ratio in the buried sandy topsoils than in the reference topsoils indicates that deep ploughing preserved SOC. The SOC mineralisation per unit SOC in the buried loamy topsoils was not significantly different from that in the reference topsoils. However, 56 ± 4% of the initial SOC was preserved in the buried topsoils. It can be concluded that deep ploughing contributes to SOC sequestration by enlarging the storage space for SOC-rich material.

  1. Evaluation of Thematic Mapper data for mapping forest, agricultural and soil resources

    NASA Technical Reports Server (NTRS)

    Degloria, S.; Benson, A.; Dummer, K.; Fakhoury, E.

    1985-01-01

    Color composite TM film products which include TM5, TM4, and a visible band (TM1, TM2, or TM3) are superior to composites which exclude TM4 for discriminating most forest and agricultural cover types and estimating area proportions for inventory and sampling purposes. Clustering a subset of TM data results in a spectral class map which groups diverse forest cover types into spectrally and ecologically similar areas suitable for use as a stratification base in traditional forest inventory practices. Analysis of simulated Thematic Mapper data indicate that the location and number of TM spectral bands are suitable for detecting differences in major soil properties and characterizing soil spectral curve form and magnitude.

  2. Occurrence of emerging contaminants in agricultural soils, sewage sludge and waters in Valencia (E Spain)

    NASA Astrophysics Data System (ADS)

    Boluda, Rafael; Marimon, Lupe; Atzeni, Stefania; Mormeneo, Salvador; Iranzo, María; Zueco, Jesús; Gamón, Miguel; Sancenón, José; Romera, David; Gil, Carlos; Amparo Soriano, Maria; Granell, Clara; Roca, Núria; Bech, Jaume

    2013-04-01

    In recent years, studies into the presence and distribution of emerging contaminants (ECs), like pharmaceutical products, some pesticides and mycotoxins in the natural environment, are receiving considerable attention. Thus, the presence of these compounds in waters, soils and wastes in different locations including agricultural systems has been stressed; very few studies into this matter are available in Spain. The main source of ECs in the environment is wastewater spillage from wastewater treatment plants (WTP), where these compounds arrive from the sewer system network. The objective of this study was to determine the levels of 35 ECs constituted by nine pharmaceutical products, 23 fungicides and three mycotoxins in soils, sewages sludge and waters adjacent to WTP from an agriculture area of Valencia (E Spain) influenced by intense urban and industrial activity. Seven samples from sludge, 13 soil samples and eight samples of waters from the area of influence of WTP were collected. The ECs extraction were performed using 5 g of fresh sample and a mixture of acetonitrile with 1% formic acid and water at the 3:1 ratio by shaking for 45 min and then centrifuging at 4,000 rpm for 5 min. The extract was filtered and determination was done by HPLC system connected to a 3200-Qtrap de triple quadrupole mass spectrometer with an electrospray ion source. The results showed that soil-ECs concentrations were 10 times lower that in sewage sludge. The smaller number of detections and detected compounds should also be stressed. As in previous cases, fungicides azole (tebuconazole and tricyclazole), along with boscalid, were the most detected compounds with concentrations of between 100 and 400 µg kg-1 dw. In second place, propiconazole and azoxystrobin stood out, followed by carbendazim, dimetomorph, pyraclostrobin and propamocarb. The following drugs and mycotoxins were detected to have a higher to lower concentration (1-40 µg kg-1): telmisartan, irbesartan, venlafaxine

  3. Use of (137)Cs technique for soil erosion study in the agricultural region of Casablanca in Morocco.

    PubMed

    Nouira, A; Sayouty, E H; Benmansour, M

    2003-01-01

    Accelerated erosion and soil degradation currently cause serious problems to the Oued El Maleh basin (Morocco). Furthermore, there is still only limited information on rates of soil loss for optimising strategies for soil conservation. In the present study we have used the (137)Cs technique to assess the soil erosion rates on an agricultural land in Oued el Maleh basin near Casablanca (Morocco). A small representative agricultural field was selected to investigate the soil degradation required by soil managers in this region. The transect approach was applied for sampling to identify the spatial redistribution of (137)Cs. The spatial variability of (137)Cs inventory has provided evidence of the importance of tillage process and the human effects on the redistribution of (137)Cs. The mean (137)Cs inventory was found about 842 Bq m(-2), this value corresponds to an erosion rate of 82 tha(-1) yr(-1) by applying simplified mass balance model in a preliminary estimation. When data on site characteristics were available, the refined mass balance model was applied to highlight the contribution of tillage effect in soil redistribution. The erosion rate was estimated about 50 tha(-1) yr(-1). The aspects related to the sampling procedures and the models for calculation of erosion rates are discussed.

  4. Enhancing soil sorption capacity of an agricultural soil by addition of three different organic wastes.

    PubMed

    Rojas, Raquel; Morillo, José; Usero, José; Delgado-Moreno, Laura; Gan, Jay

    2013-08-01

    This study evaluated the ability of three unmodified organic residues (composted sewage sludge, RO1; chicken manure, RO2; and a residue from olive oil production called 'orujillo', RO3) and a soil to sorb six pesticides (atrazine, lindane, alachlor, chlorpyrifos, chlorfenvinphos and endosulfan sulfate) and thereby explored the potential environmental value of these organic residues for mitigating pesticide pollution in agricultural production and removing contaminants from wastewater. Pesticide determination was carried out using gas chromatography coupled with mass spectrometry. Adsorption data were analyzed by the Langmuir and Freundlich adsorption approaches. Experimental results showed that the Freundlich isotherm model best described the adsorption process and that Kf values increased with an increase in organic matter (OM) content of the amended soil. The order of adsorption of pesticides on soils was: chlorpyrifos≥endosulfan sulfate>chlorfenvinphos≥lindane>alachlor≥atrazine. The sorption was greater for the most hydrophobic compounds and lower for the most polar ones, as corroborated by a negative correlation between Kf values and solubility. Sorption increased with an increase in organic matter. Sorption capacity was positively correlated with the organic carbon (OC) content. The organic amendment showing the maximum sorption capacity was RO3 in all cases, except for chlorfenvinphos, in which it was RO2. The order of adsorption capacity of the amendments depended on the pesticide and the organic dosage. In the case of the 10% amendment the order was RO3>RO2>RO1>soil, except for chlorfenvinphos, in which it was RO2>RO3>RO1>soil, and atrazine, where RO2 and RO3 amendments had the same effect on the soil sorption capacity (RO2≥RO3>RO1>soil).

  5. Climatic and agricultural drivers of soil erosion in Africa

    NASA Astrophysics Data System (ADS)

    Irvine, Brian; Kirkby, Mike; Fleskens, Luuk

    2015-04-01

    Soil erosion was the most frequently identified driver of land degradation across a selection of global research sites within the DESIRE-EU project. The PESERA model was adopted in the project to upscale field results and consider the potential biophysical impact both with and without stakeholder selected sustainable land management (SLM) technologies in place. The PESERA model was combined with the DESMICE economic model and focussed on forecasting the regional effects of combating desertification both in environmental and socio-economical terms. The PESERA-DESMICE approach is further developed in the WAHARA project to consider the potential of a range of water harvesting technologies to improve biophysical conditions. Modelling in the WAHARA project considers detail of water harvesting technologies at the study site scale through to a coarser application at the continental scale with the latter being informed by the detail provided by study site observations an approach adopted in DESIRE-EU. The PESERA-DESMICE approach considers the difference between a baseline scenario and a (water harvesting) technology scenario at both scales in terms of productivity, financial viability and scope for reducing erosion risk. This paper considers the continental scale and focuses on estimating the impact of in-situ water harvesting technologies across Africa under current and future agricultural and climate pressure. PESERA is adopted in this continental application as it implicitly considers the impact of land-use and climate and can be readily amended to simulate in-situ WHT. Input data for PESERA; land use, management (crop type and planting dates), soil data and topography are derived from global data resources. Climate data for present and future scenarios are available through the QUEST-GSI initiative, where future scenarios are based on the outputs of seven GCM's.

  6. Increasing Efficiency of Water Use in Agriculture through Management of Soil Water Repellency to Optimize Soil and Water Productivity

    NASA Astrophysics Data System (ADS)

    Moore, Demie; Kostka, Stan; McMillan, Mica; Gadd, Nick

    2010-05-01

    Water's ability to infiltrate and disperse in soils, and soil's ability to receive, transport, retain, filter and release water are important factors in the efficient use of water in agriculture. Deteriorating soil conditions, including development of soil water repellency, negatively impact hydrological processes and, consequently, the efficiency of rainfall and irrigation. Soil water repellency is increasingly being identified in diverse soils and cropping systems. Recently research has been conducted on the use of novel soil surfactants (co-formulations of alkyl polyglycoside and block copolymer surfactants) to avoid or overcome soil water repellency and enhance water distribution in soils. Results indicate that this is an effective and affordable approach to maintaining or restoring soil and water productivity in irrigated cropping systems. Results from studies conducted in Australia and the United States to determine how this technology modifies soil hydrological behavior and crop yields will be presented. A range of soils and various crops, including potatoes, corn, apples and grapes, were included. Several rates were compared to controls for effect on soil moisture levels, soil water distribution, and crop yield. An economic analysis was also conducted in some trials. Treatments improved rootzone water status, significantly increased crop yield and quality, and in some cases allowed significant reductions in water requirements. Where assessed, a positive economic return was generated. This technology holds promise as a strategy for increasing efficiency of water use in agriculture.

  7. Terra Pretas: Charcoal Amendments Influence on Relict Soils and Modern Agriculture

    ERIC Educational Resources Information Center

    Ricigliano, Kristin

    2011-01-01

    Most soils found in the Amazon region are characterized by highly weathered profiles that are incapable of longterm agricultural production. However, small patches of highly fertile relict soil referred to as Terra Pretas, are also found in the Amazon region, and have maintained their integrity for thousands of years. These soils were…

  8. Validating a digital soil map with corn yield data for precision agriculture decision support

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Variability in soil and landscape characteristics is known to challenge producers in implementing site-specific crop management strategies in precision agriculture (PA). There are growing numbers of digital soil mapping (DSM) procedures that build upon traditional soil survey information by employin...

  9. INNOVATIONS IN SOIL SAMPLING AND DATA ANALYSIS

    EPA Science Inventory

    Successful research outcomes from the VOC in soils work will provide the Agency with methods and techniques that provide the accurate VOC concentrations so that decisions related to a contaminated site can be made to optimize the protectiveness to the environment and human health...

  10. Deriving soil function maps to assess related ecosystem services using imaging spectroscopy in the Lyss agricultural area, Switzerland

    NASA Astrophysics Data System (ADS)

    Diek, Sanne; de Jong, Rogier; Braun, Daniela; Böhler, Jonas; Schaepman, Michael

    2014-05-01

    Soils play an important role in the benefits offered by ecosystems services. In densely populated Switzerland soils are a scarce resource, with high pressure on services ranging from urban expansion to over-utilization. Key change drivers include erosion, soil degradation, land management change and (chemical) pollution, which should be taken into consideration. Therefore there is an emerging need for an integrated, sustainable and efficient system assessing the management of soil and land as a resource. The use of remote sensing can offer spatio-temporal and quantitative information of extended areas. In particular imaging spectroscopy has shown to perfectly complement existing sampling schemes as secondary information for digital soil mapping. Although only the upper-most layer of soil interacts with light when using reflectance spectroscopy, it still can offer valuable information that can be utilized by farmers and decision makers. Fully processed airborne imaging spectrometer data from APEX as well as land cover classification for the agricultural area in Lyss were available. Based on several spectral analysis methods we derived multiple soil properties, including soil organic matter, soil texture, and mineralogy; complemented by vegetation parameters, including leaf area index, chlorophyll content, pigment distribution, and water content. The surface variables were retrieved using a combination of index-based and physically-based retrievals. Soil properties in partly to fully vegetated areas were interpolated using regression kriging based methods. This allowed the continuous assessment of potential soil functions as well as non-contiguous maps of abundances of combined soil and vegetation parameters. Based on a simple regression model we could make a rough estimate of ecosystem services. This provided the opportunity to look at the differences between the interpolated soil function maps and the non-contiguous (but combined) vegetation and soil function maps

  11. [Three patterns of interaction between soil and non-point source P-pollutants in agricultural watershed].

    PubMed

    Wang, Xia-hui; Yin, Cheng-qing; Yan, Xiao; Shan, Bao-qing; Wang, Wei-dong

    2004-07-01

    Typical agricultural watershed was selected to study the interactions between soil matrix and non-point source P-pollutants in surface runoff under simulative conditions. The soil samples were taken in different spatial locations in this watershed and were under different degree of human disturbance. The results showed that the interactions between different soil matrix and phosphorus could be divided into three patterns:retention, release and combination of retention and release. Soil of retention pattern has strong adsorption capacity of phosphate and will retain phosphorus from polluted runoff. Soil of release pattern has significant desorption capacity of phosphate and will release phosphorus to the runoff. Soil of retention and release combination pattern will retain or release phosphorus according to the phosphate concentration in the polluted runoff. These results showed that soil matrix in different spatial locations in the agricultural watershed have different ecological functions and environmental values under the processing of natural conditions and human disturbance. From the view of occurrence of non-point source pollution, these soils could become the sink of pollutants as well as the source of pollutants. Under some conditions, there has a conversion between sink and source of them. These results are valuable for control of non-point source pollution on watershed level, identification of key source area of pollutants and improvement of efficiency of control measures.

  12. Speciation and bioavailability of some heavy metals in agricultural soils used for cultivating various vegetables in Bedugul, Bali

    NASA Astrophysics Data System (ADS)

    Siaka, I. Made; Utama, I. Made Supartha; Manuaba, I. B. Putra; Adnyana, I. Made; Sahara, Emmy

    2016-03-01

    This paper discusses the speciation and bioavailability of some heavy metals in agricultural soils used to cultivate various vegetables in Bedugul, Bali. Vegetables grown on contaminated soils where agrochemicals were applied uncontrolled could contain a number of heavy metals. This could occur in the vegetables produced from agricultural soils of Bedugul as the farmers applied agrochemicals excessively. In considering the metals transport to the vegetables, a speciation and bioavailability methods were necessary to be studied. Wet digestion and sequential extraction techniques were employed to the sample prior to the metals measurement by AAS. The results showed that the average concentrations of Pb, Cu, Cd, Cr, and Zn in the soils were 38.531, 132.126, 7.689, 15.952, and 147.275 mg/kg, respectively. The highest concentrations of Pb and Zn were found in the soil for cultivating lettuce, Cd and Cr in the soil for tomato, and Cu in the soil for potatoes. It was found that the speciation of Pb, Cu, Cd, and Cr were predominantly bound to Fe-Mn oxides fraction, while Zn was mostly associated with the EFLE (easily, freely, leachable, and exchangeable) fractions. The highest bioavailability among the metals in the studied soils was Cr, while the lowest was Cu.

  13. Variations in the bioavailability of polycyclic aromatic hydrocarbons in industrial and agricultural soils after bioremediation.

    PubMed

    Guo, Meixia; Gong, Zongqiang; Allinson, Graeme; Tai, Peidong; Miao, Renhui; Li, Xiaojun; Jia, Chunyun; Zhuang, Jie

    2016-02-01

    The aim of this study was to demonstrate the variations in bioavailability remaining in industrial and agricultural soils contaminated by polycyclic aromatic hydrocarbons (PAHs) after bioremediation. After inoculation of Mycobacterium sp. and Mucor sp., PAH biodegradation was tested on a manufactured gas plant (MGP) soil and an agricultural soil. PAH bioavailability was assessed before and after biodegradation using solid-phase extraction (Tenax-TA extraction) and solid-phase micro-extraction (SPME) to represent bioaccessibility and chemical activity of PAHs, respectively. Only 3- and 4-ring PAHs were noticeably biodegradable in the MGP soil. PAH biodegradation in the agricultural soil was different from that in the MGP soil. The rapidly desorbing fractions (F(rap)) extracted by Tenax-TA and the freely dissolved concentrations of 3- and 4-ring PAHs determined by SPME from the MGP soil decreased after 30 days biodegradation; those values of the 5- and 6-ring PAHs changed to a lesser degree. For the agricultural soil, the F(rap) values of the 3- and 4-ring PAHs also decreased after the biodegradation experiment. The Tenax-TA extraction and the SPME have the potential to assess variations in the bioavailability of PAHs and the degree of biodegradation in contaminated MGP soils. In addition, Tenax-TA extraction is more sensitive than SPME when used in the agricultural soil.

  14. Natural radioactivity levels of geothermal waters and their influence on soil and agricultural activities.

    PubMed

    Murat Saç, Müslim; Aydemir, Sercan; Içhedef, Mutlu; Kumru, Mehmet N; Bolca, Mustafa; Ozen, Fulsen

    2014-01-01

    All over the world geothermal sources are used for different purposes. The contents of these waters are important to understand positive/negative effects on human life. In this study, natural radioactivity concentrations of geothermal waters were investigated to evaluate the effect on soils and agricultural activities. Geothermal water samples were collected from the Seferihisar Geothermal Region, and the radon and radium concentrations of these waters were analysed using a collector chamber method. Also soil samples, which are irrigated with geothermal waters, were collected from the surroundings of geothermal areas, and natural radioactivity concentrations of collected samples (U, Th and K) were determined using an NaI(Tl) detector system. The activity concentrations of radon and radium were found to be 0.6-6.0 and 0.1-1.0 Bq l(-1), respectively. Generally, the obtained results are not higher compared with the geothermal waters of the world. The activity concentrations in soils were found to be in the range of 3.3-120.3 Bq kg(-1) for (226)Ra (eU), 0.3-108.5 Bq kg(-1) for (232)Th (eTh), 116.0-850.0 Bq kg(-1) for (40)K (% K).

  15. Modeling of 137Cs migration in soils using an 80-year soil archive: role of fertilizers and agricultural amendments.

    PubMed

    Monna, F; van Oort, F; Hubert, P; Dominik, J; Bolte, J; Loizeau, J-L; Labanowski, J; Lamri, J; Petit, C; Le Roux, G; Chateau, C

    2009-01-01

    An 80-year soil archive, the 42-plot experimental design at the INRA in Versailles (France), is used here to study long-term contamination by 137Cs atmospheric deposition and the fate of this radioisotope when associated with various agricultural practices: fallow land, KCl, NH4(NO3), superphosphate fertilizers, horse manure and lime amendments. The pertinence of a simple box model, where radiocaesium is supposed to move downward by convectional mechanisms, is checked using samples from control plots which had been neither amended, nor cultivated since 1928. This simple model presents the advantage of depending on only two parameters: alpha, a proportional factor allowing the historical atmospheric 137Cs fluxes to be reconstructed locally, and k, an annual loss coefficient from the plow horizon. Another pseudo-unknown is however necessary to run the model: the shape of historical 137Cs deposition, but this function can be easily computed by merging several curves previously established by other surveys. A loss of approximately 1.5% per year from the plow horizon, combined with appropriate fluxes, provides good concordance between simulated and measured values. In the 0-25cm horizon, the residence half time is found to be approximately 18yr (including both migration and radioactive decay). Migration rate constants are also calculated for some plots receiving continuous long-term agricultural treatments. Comparison with the control plots reveals significant influence of amendments on 137Cs mobility in these soils developed from a unique genoform. PMID:19013695

  16. Modeling of 137Cs migration in soils using an 80-year soil archive: role of fertilizers and agricultural amendments.

    PubMed

    Monna, F; van Oort, F; Hubert, P; Dominik, J; Bolte, J; Loizeau, J-L; Labanowski, J; Lamri, J; Petit, C; Le Roux, G; Chateau, C

    2009-01-01

    An 80-year soil archive, the 42-plot experimental design at the INRA in Versailles (France), is used here to study long-term contamination by 137Cs atmospheric deposition and the fate of this radioisotope when associated with various agricultural practices: fallow land, KCl, NH4(NO3), superphosphate fertilizers, horse manure and lime amendments. The pertinence of a simple box model, where radiocaesium is supposed to move downward by convectional mechanisms, is checked using samples from control plots which had been neither amended, nor cultivated since 1928. This simple model presents the advantage of depending on only two parameters: alpha, a proportional factor allowing the historical atmospheric 137Cs fluxes to be reconstructed locally, and k, an annual loss coefficient from the plow horizon. Another pseudo-unknown is however necessary to run the model: the shape of historical 137Cs deposition, but this function can be easily computed by merging several curves previously established by other surveys. A loss of approximately 1.5% per year from the plow horizon, combined with appropriate fluxes, provides good concordance between simulated and measured values. In the 0-25cm horizon, the residence half time is found to be approximately 18yr (including both migration and radioactive decay). Migration rate constants are also calculated for some plots receiving continuous long-term agricultural treatments. Comparison with the control plots reveals significant influence of amendments on 137Cs mobility in these soils developed from a unique genoform.

  17. Crop monoculture rather than agriculture reduces the spatial turnover of soil bacterial communities at a regional scale.

    PubMed

    Figuerola, Eva L M; Guerrero, Leandro D; Türkowsky, Dominique; Wall, Luis G; Erijman, Leonardo

    2015-03-01

    The goal of this study was to investigate the spatial turnover of soil bacterial communities in response to environmental changes introduced by the practices of soybean monoculture or crop rotations, relative to grassland soils. Amplicon sequencing of the 16S rRNA gene was used to analyse bacterial diversity in producer fields through three successive cropping cycles within one and a half years, across a regional scale of the Argentinean Pampas. Unlike local diversity, which was not significantly affected by land use type, agricultural management had a strong influence on β-diversity patterns. Distributions of pairwise distances between all soils samples under soybean monoculture had significantly lower β-diversity and narrower breadth compared with distributions of pairwise distances between soils managed with crop rotation. Interestingly, good agricultural practices had similar degree of β-diversity as natural grasslands. The higher phylogenetic relatedness of bacterial communities in soils under monoculture across the region was likely determined by the observed loss of endemic species, and affected mostly to phyla with low regional diversity, such as Acidobacteria, Verrucomicrobia and the candidates phyla SPAM and WS3. These results suggest that the implementation of good agricultural practices, including crop rotation, may be critical for the long-term conservation of soil biodiversity. PMID:24803003

  18. Crop monoculture rather than agriculture reduces the spatial turnover of soil bacterial communities at a regional scale.

    PubMed

    Figuerola, Eva L M; Guerrero, Leandro D; Türkowsky, Dominique; Wall, Luis G; Erijman, Leonardo

    2015-03-01

    The goal of this study was to investigate the spatial turnover of soil bacterial communities in response to environmental changes introduced by the practices of soybean monoculture or crop rotations, relative to grassland soils. Amplicon sequencing of the 16S rRNA gene was used to analyse bacterial diversity in producer fields through three successive cropping cycles within one and a half years, across a regional scale of the Argentinean Pampas. Unlike local diversity, which was not significantly affected by land use type, agricultural management had a strong influence on β-diversity patterns. Distributions of pairwise distances between all soils samples under soybean monoculture had significantly lower β-diversity and narrower breadth compared with distributions of pairwise distances between soils managed with crop rotation. Interestingly, good agricultural practices had similar degree of β-diversity as natural grasslands. The higher phylogenetic relatedness of bacterial communities in soils under monoculture across the region was likely determined by the observed loss of endemic species, and affected mostly to phyla with low regional diversity, such as Acidobacteria, Verrucomicrobia and the candidates phyla SPAM and WS3. These results suggest that the implementation of good agricultural practices, including crop rotation, may be critical for the long-term conservation of soil biodiversity.

  19. Comparison of agricultural soils' structure depending on tillage system using X-ray microtomography

    NASA Astrophysics Data System (ADS)

    Beckers, Eléonore; Degré, Aurore; Ly, Sarann; Léonard, Angélique

    2010-05-01

    This study aims at characterizing agricultural soils' structure depending on the tillage system: conventional tillage or conservational tillage. Tillage reduction is an increasing practice, but the micro-structural effects on soils and on their hydrodynamic parameters are still not well described. Recent research shows non-converging results. Our point is to highlight fundamental differences in structure through characterization of soils porosity's parameters using X-ray microtomography measurements coupled to image analysis. This attempt is in line with a more integrated experiment of which the aim is to quantify the effects of tillage intensity on lateral flow production, and finally on global water balance. Parameters' measurements consist in a combined approach, based on two different space-time scales of exploration: fundamental scale, with soil sampling campaign for microtomography analysis, and field scale, with continuous flow measurements (plots' dimensions: 18*28 m). For their part, parameters for water balance determination (precipitation, evapotranspiration…) are monitored on the field. All of these measurements have the main objective of hydrological modeling enhancement by taking into account a better lateral flow description. Discussion in this paper will focus on the first results obtained by X-ray microtomography measurements. Our experiment takes place in Gentinnes (Walloon Brabant, Belgium), on a field organized in a split-plot scheme. Since 2004, plots have been cultivated in conventional tillage or in reduced tillage. The latter consists in sowing after stubble ploughing of about 10cm. The crop rotation is sugar beet followed by winter wheat. The soil is mainly composed of silt loam. Soils samples, with a 3 cm diameter and a 5 cm height, were removed from the upper layer (Ap horizon) for both management practices. Samples are scanned by X-ray microtomography using a Skyscan-1172 high-resolution desk-top micro-CT system (Skyscan, Kontich

  20. GEMAS: A unique data set to define magnetic susceptibility variability of European agricultural soil

    NASA Astrophysics Data System (ADS)

    Fabian, Karl; Reimann, Clemens

    2014-05-01

    The GEMAS data set provides the first comprehensive overview of magnetic susceptibility in European soil. Samples from the upper 20cm were taken in large agricultural fields (Ap-sample). After air drying and sieving to < 2mm, weight specific magnetic susceptibility k was measured using a Sapphire Instruments SI2B bridge with dynamic background correction. k quantifies the magnetic response to a small change of the external magnetic field. k is typically high in samples with a high concentration of iron oxides (magnetite, maghemite, haematite), iron hydroxides (goethite, limonite), or iron sulphides (pyrrhotite, greigite), and low for soil with high carbonate or silica content. While the median value in Ap soil is 0.207 × 10-6m3/kg, k varies over four orders of magnitude and allows for a clear classification. Its spatial distribution shows a broad distinct low over the sandy sediments of the last glaciation in central northern Europe, which consist primarily of quartz (SiO2) with very little amounts of iron and iron oxides. Other broad minima in k are also related to sedimentary basins. Localised, consistently positive, k anomalies occur near young volcanism, or old basalts exposed on the surface. Also iron ore provinces or mineralizations, e.g. the Iberian Pyrite Belt, are associated with high k. Elevated k values due to precipitation and subsequent weathering are found in Mediterranean chromic luvisols (terra rossa). On the European scale a unique signal of anthropogenic enhancement of k in Ap soil cannot be distinguished. All major features of the k distribution can be related to geology. Thereby, the GEMAS data set of magnetic susceptibility provides a continent wide reference of the natural background of k in Ap soil. It can be used to define the geological background variability for national and local studies, where this knowledge is needed to distinguish between anthropogenic and geogenic sources of observed k anomalies.

  1. Biodegradation of chlorpyrifos by bacterial consortium isolated from agriculture soil.

    PubMed

    Sasikala, Chitrambalam; Jiwal, Sonia; Rout, Pallabi; Ramya, Mohandass

    2012-03-01

    Organophosphorous pesticides are widely used in agriculture to control major insect pests. Chlorpyrifos is one of the major organophosphorous pesticides which is used to control insects including termites, beetles. The widespread use of these pesticides is hazardous to the environment and also toxic to mammals, thus it is essential to remove the same from the environment. From the chlorpyrifos contaminated soil nine morphologically different bacterial strains, one actinomycete and two fungal strains were isolated. Among those isolates four bacterial strains which were more efficient were developed as consortium. The four bacterial isolates namely Pseudomonas putida (NII 1117), Klebsiella sp., (NII 1118), Pseudomonas stutzeri (NII 1119), Pseudomonas aeruginosa (NII 1120) present in the consortia were identified on the basis of 16S rDNA analysis. The intracellular fractions of the consortium exhibited more organophosphorus hydrolase activity (0.171 ± 0.003 U/mL/min). The degradation studies were carried out at neutral pH and temperature 37°C with chlorpyrifos concentration 500 mg L(-1). LC-mass spectral analysis showed the presence of metabolites chlopyrifos-oxon and Diethylphosphorothioate. These results highlight an important potential use of this consortium for the cleanup of chlorpyrifos contaminated pesticide waste in the environment.

  2. Changes in soil microbial community structure following the abandonment of agricultural terraces in mountainous areas of Eastern Spain

    PubMed Central

    Zornoza, R.; Guerrero, C.; Mataix-Solera, J.; Scow, K.M.; Arcenegui, V.; Mataix-Beneyto, J.

    2012-01-01

    In Eastern Spain, almond trees have been cultivated in terraced orchards for centuries, forming an integral part of the Mediterranean forest scene. In the last decades, orchards have been abandoned due to changes in society. This study investigates effects of changes in land use from forest to agricultural land and the posterior land abandonment on soil microbial community, and the influence of soil physico-chemical properties on the microbial community composition (assessed as abundances of phospholipids fatty acids, PLFA). For this purpose, three land uses (forest, agricultural and abandoned agricultural) at four locations in SE Spain were selected. Multivariate analysis showed a substantial level of differentiation in microbial community structure according to land use. The microbial communities of forest soils were highly associated with soil organic matter content. However, we have not found any physical or chemical soil property capable of explaining the differences between agricultural and abandoned agricultural soils. Thus, it was suggested that the cessation of the perturbation caused by agriculture and shifts in vegetation may have led to changes in the microbial community structure. PLFAs indicative of fungi and ratio of fungal to bacterial PLFAs were higher in abandoned agricultural soils, whereas the relative abundance of bacteria was higher in agricultural soils. Actinomycetes were generally lower in abandoned agricultural soils, while the proportions of vesicular-arbuscular mycorrhyzal fungi were, as a general trend, higher in agricultural and abandoned agricultural soils than in forests. Total microbial biomass and richness increased as agricultural < abandoned agricultural < forest soils. PMID:22291451

  3. How Well Does Zone Sampling Based On Soil Electrical Conductivity Maps Represent Soil Variability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Zone soil sampling is a method in which a field sampling is based on identifying homogenous areas using an easy to measure ancillary attribute such as apparent soil electrical conductivity (ECa). This study determined if ECa-directed zone sampling in two fields in northeastern Colorado could correc...

  4. Arsenic pollution of agricultural soils by concentrated animal feeding operations (CAFOs).

    PubMed

    Liu, Xueping; Zhang, Wenfeng; Hu, Yuanan; Hu, Erdan; Xie, Xiande; Wang, Lingling; Cheng, Hefa

    2015-01-01

    Animal wastes from concentrated animal feeding operations (CAFOs) can cause soil arsenic pollution due to the widespread use of organoarsenic feed additives. This study investigated the arsenic pollution of surface soils in a typical CAFO zone, in comparison with that of agricultural soils in the Pearl River Delta, China. The mean soil arsenic contents in the CAFO zone were elevated compared to those in the local background and agricultural soils of the Pearl River Delta region. Chemical speciation analysis showed that the soils in the CAFO zone were clearly contaminated by the organoarsenic feed additive, p-arsanilic acid (ASA). Transformation of ASA to inorganic arsenic (arsenite and arsenate) in the surface soils was also observed. Although the potential ecological risk posed by the arsenic in the surface soils was relatively low in the CAFO zone, continuous discharge of organoarsenic feed additives could cause accumulation of arsenic and thus deserves significant attention. PMID:25036941

  5. Flow Cell Sampling Technique: A new approach to analyze physical soil and particle surface properties of undisturbed soil samples

    NASA Astrophysics Data System (ADS)

    Krueger, Jiem; Leue, Martin; Heinze, Stefanie; Bachmann, Jörg

    2016-04-01

    During unsaturated water conditions, water flow occurs in the soil mainly by water film flow and depends on moisture content and pore surface properties. More attention is attributed to coatings enclosing soil particles and thus may affect wetting properties as well as hydraulic soil functions. Particle coatings are most likely responsible for many adsorption processes and are expected to favor local heterogeneous microstructure with enhanced biological activity. Many of the effects described cannot be detected on the basis of conventional soil column experiments, which were usually made to study soil hydraulic processes or surface - soil solution exchange processes. The general objective of this study was to develop a new field sampling method to unravel heterogeneous flow processes on small scales in an undisturbed soil under controlled lab conditions. This will be done by using modified flow cells (Plexiglas). Beside the measurements within a flow cell as breakthrough curves, the developed technique has several additional advantages in contrast to common columns or existing flow chamber/cell designs. The direct modification from the sampling frame to the flow cell provides the advantage to combine several analyses. The new technique enables to cut up to 5 thin undisturbed soil slices (quasi-replicates) down to 10 and/or 5 mm. Relative large particles, for instance, may limit this sampling method. The large observation area of up to 150 cm2 allows the characterization of particle surface properties in a high spatial resolution within an undisturbed soil sample. This sampling technique, as shown in our study, has the opportunity to link soil wetting hydraulic and several particle surface properties to spatial soil heterogeneities. This was shown with tracer experiments, small-scale contact angle measurements and analyses of the spatial distribution of functional groups of soil organic matter via DRIFT mapping.

  6. Glyphosate and AMPA contents in sediments produced by wind erosion of agricultural soils in Argentina

    NASA Astrophysics Data System (ADS)

    Aparicio, Virginia; Aimar, Silvia; De Gerónimo, Eduardo; Buschiazzo, Daniel; Mendez, Mariano; Costa, José Luis

    2014-05-01

    Wind erosion of soils is an important event in arid and semiarid regions of Argentina. The magnitude of wind erosion occurring under different management practices is relatively well known in this region but less information is available on the quality of the eroded material. Considering that the intensification of agriculture may increase the concentrations of substances in the eroded material, producing potential negative effects on the environment, we analyzed the amount of glyphosate and AMPA in sediments produced by wind erosion of agricultural soils of Argentina. Wind eroded materials were collected by means of BSNE samplers in two loess sites of the semiarid region of Argentina: Chaco and La Pampa. Samples were collected from 1 ha square fields at 13.5, 50 and 150 cm height. Results showed that at higher heights the concentrations of glyphosate and AMPA were mostly higher. The glyphosate concentration was more variable and higher in Chaco (0.66 to 313 µg kg-1) than in La Pampa (4.17 to 114 µg kg-1). These results may be due to the higher use of herbicides in Chaco, where the predominant crops are soybeans and corn, produced under no-tillage. Under these conditions the use of glyphosate for weeds control is a common practice. Conversely, AMPA concentrations were higher in La Pampa (13.1 to 101.3 µg kg-1) than in Chaco (1.3 to 83 µg kg-1). These preliminary results show high concentrations of glyphosate and AMPA in wind eroded materials of agricultural soils of Argentina. More research is needed to confirm these high concentrations in other conditions in order to detect the temporal and spatial distribution patterns of the herbicide.

  7. Lead in Urban Soils: A Real or Perceived Concern for Urban Agriculture?

    PubMed

    Brown, Sally L; Chaney, Rufus L; Hettiarachchi, Ganga M

    2016-01-01

    Urban agriculture is growing in cities across the United States. It has the potential to provide multiple benefits, including increased food security. Concerns about soil contamination in urban areas can be an impediment to urban agriculture. Lead is the most common contaminant in urban areas. In this paper, direct (soil ingestion via outdoor and indoor exposure) and indirect (consumption of food grown in Pb-contaminated soils) exposure pathways are reviewed. It is highly unlikely that urban agriculture will increase incidences of elevated blood Pb for children in urban areas. This is due to the high likelihood that agriculture will improve soils in urban areas, resulting in reduced bioavailability of soil Pb and reduced fugitive dust. Plant uptake of Pb is also typically very low. The exceptions are low-growing leafy crops where soil-splash particle contamination is more likely and expanded hypocotyl root vegetables (e.g., carrot). However, even with higher bioaccumulation factors, it is not clear that the Pb in root vegetables or any other crops will be absorbed after eating. Studies have shown limited absorption of Pb when ingested with food. Best management practices to assure minimal potential for exposure are also common practices in urban gardens. These include the use of residuals-based composts and soil amendments and attention to keeping soil out of homes. This review suggests that benefits associated with urban agriculture far outweigh any risks posed by elevated soil Pb.

  8. Lead in Urban Soils: A Real or Perceived Concern for Urban Agriculture?

    PubMed

    Brown, Sally L; Chaney, Rufus L; Hettiarachchi, Ganga M

    2016-01-01

    Urban agriculture is growing in cities across the United States. It has the potential to provide multiple benefits, including increased food security. Concerns about soil contamination in urban areas can be an impediment to urban agriculture. Lead is the most common contaminant in urban areas. In this paper, direct (soil ingestion via outdoor and indoor exposure) and indirect (consumption of food grown in Pb-contaminated soils) exposure pathways are reviewed. It is highly unlikely that urban agriculture will increase incidences of elevated blood Pb for children in urban areas. This is due to the high likelihood that agriculture will improve soils in urban areas, resulting in reduced bioavailability of soil Pb and reduced fugitive dust. Plant uptake of Pb is also typically very low. The exceptions are low-growing leafy crops where soil-splash particle contamination is more likely and expanded hypocotyl root vegetables (e.g., carrot). However, even with higher bioaccumulation factors, it is not clear that the Pb in root vegetables or any other crops will be absorbed after eating. Studies have shown limited absorption of Pb when ingested with food. Best management practices to assure minimal potential for exposure are also common practices in urban gardens. These include the use of residuals-based composts and soil amendments and attention to keeping soil out of homes. This review suggests that benefits associated with urban agriculture far outweigh any risks posed by elevated soil Pb. PMID:26828157

  9. Emission factors for organic fertilizer-induced N2O emissions from Japanese agricultural soils

    NASA Astrophysics Data System (ADS)

    Sano, T.; Nishina, K.; Sudo, S.

    2013-12-01

    1. Introduction Agricultural fields are significant sources of nitrous oxide (N2O), which is one of the important greenhouse gases with a contribution of 7.9% to the anthropogenic global warming (IPCC, 2007). Direct fertilizer-induced N2O emission from agricultural soil is estimated using the emission factor (EF). National greenhouse gas inventory of Japan defines direct EF for N2O associated with the application of chemical and organic fertilizers as the same value (0.62%) in Japanese agricultural fields. However, it is necessary to estimate EF for organic fertilizers separately, because there are some differences in factors controlling N2O emissions (e.g. nutrient content) between chemical and organic fertilizers. The purpose of this study is to estimate N2O emissions and EF for applied organic fertilizers in Japanese agricultural fields. 2. Materials and Methods We conducted the experiments at 10 prefectural agricultural experimental stations in Japan (Yamagata, Fukushima, Niigata, Ibaraki, Aichi, Shiga, Tokushima, Nagasaki, Kumamoto, and Kagoshima) to consider the variations of cultivation and environmental conditions among regions. Field measurements had been conducted for 2-2.5 years during August 2010-April 2013. Each site set experimental plots with the applications of composted manure (cattle, swine, and poultry), chemical fertilizer, and non-nitrogen fertilizer as a control. The annual amount of applied nitrogen ranged from 16 g-N m-2 y-1 to 60 g-N m-2 y-1 depending on cropping system and cultivated crops (e.g. cabbage, potato) at each site. N2O fluxes were measured using a closed-chamber method. N2O concentrations of gas samples were measured with gas chromatography. The EF value of each fertilizer was calculated as the N2O emission from fertilizer plots minus the background N2O emission (emission from a control plot), and was expressed as a percentage of the applied nitrogen. The soil NH4+ and NO3-, soil temperature, precipitation, and WFPS (water

  10. Determination of total petroleum hydrocarbons (TPH) in agricultural soils near a petrochemical complex in Guangzhou, China.

    PubMed

    Li, Junhui; Zhang, Juntao; Lu, Ying; Chen, Yiqin; Dong, Shanshan; Shim, Hojae

    2012-01-01

    The total petroleum hydrocarbons (TPH) pollution in regional agricultural soils was investigated. Seventy soil samples collected from surface layers (0-20 cm) and horizons of five selected pedons in the vicinity of a petrochemical complex in Guangzhou, China were analyzed, and the vertical variation and spatial variability of TPH were evaluated. The TPH concentration in top soils around the petrochemical complex ranged from 1,179.3 to 6,354.9 mg kg( - 1), with the average of 2,676.6 mg kg( - 1). Furthermore, significant differences between land-use types showed that the TPH concentration in top soils was strongly influenced by accidental spills. Both the TPH trends in pedons and the identified hot-spot areas also showed that the accidental explosions or burning accidents were mainly responsible for the pollution. The results reported here suggest that the regular monitoring and inspection shall be conducted for safety and to avoid or minimize the accidents, and the effective measures should be taken to remediate the contaminated areas and to assure that the important industrialization of Guangzhou area would not mean human health risks near the petrochemical complex.

  11. Soil hydrological and soil property changes resulting from termite activity on agricultural fields in Burkina Faso

    NASA Astrophysics Data System (ADS)

    Mettrop, I.; Cammeraat, L. H.; Verbeeten, E.

    2009-04-01

    Termites are important ecosystem-engineers in subtropical and tropical regions. The effect of termite activity affecting soil infiltration is well documented in the Sahelian region. Most studies find increased infiltration rates on surfaces that are affected by termite activity in comparison to crusted areas showing non-termite presence. Crusted agricultural fields in the Sanmatenga region in Burkina Faso with clear termite activity were compared to control fields without visual ground dwelling termite activity. Fine scale rainfall simulations were carried out on crusted termite affected and control sites. Furthermore soil moisture change, bulk density, soil organic matter as well as general soil characteristics were studied. The top soils in the study area were strongly crusted (structural crust) after the summer rainfall and harvest of millet. They have a loamy sand texture underlain by a shallow sandy loam Bt horizon. The initial soil moisture conditions were significantly higher on the termite plots when compared to control sites. It was found that the amount of runoff produced on the termite plots was significantly higher, and also the volumetric soil moisture content after the experiments was significantly lower if compared to the control plots. Bulk density showed no difference whereas soil organic matter was significantly higher under termite affected areas, in comparison to the control plots. Lab tests showed no significant difference in hydrophobic behavior of the topsoil and crust material. Micro and macro-structural properties of the topsoil did not differ significantly between the termite sites and the control sites. The texture of the top 5 cm of the soil was also found to be not significantly different. The infiltration results are contradictory to the general literature, which reports increased infiltration rates after prolonged termite activity although mostly under different initial conditions. The number of nest entrances was clearly higher in

  12. Comparison of soil microbial respiration and carbon turnover under perennial and annual biofuel crops in two agricultural soils

    NASA Astrophysics Data System (ADS)

    Szymanski, L. M.; Marin-Spiotta, E.; Sanford, G. R.; Jackson, R. D.; Heckman, K. A.

    2015-12-01

    Bioenergy crops have the potential to provide a low carbon-intensive alternative to fossil fuels. More than a century of agricultural research has shown that conventional cropping systems can reduce soil organic matter (SOM) reservoirs, which cause long-term soil nutrient loss and C release to the atmosphere. In the face of climate change and other human disruptions to biogeochemical cycles, identifying biofuel crops that can maintain or enhance soil resources is desirable for the sustainable production of bioenergy. The objective of our study was to compare the effects of four biofuel crop treatments on SOM dynamics in two agricultural soils: Mollisols at Arlington Agricultural Research Station in Wisconsin and Alfisols at Kellogg Biological Station in Michigan, USA. We used fresh soils collected in 2013 and archived soils from 2008 to measure the effects of five years of crop management. Using a one-year long laboratory soil incubation coupled with a regression model and radiocarbon measurements, we separated soils into three SOM pools and their corresponding C turnover times. We found that the active pool, or biologically available C, was more sensitive to management and is an earlier indicator of changes to soil C dynamics than bulk soil C measurements. There was no effect of treatment on the active pool size at either site; however, the percent C in the active pool decreased, regardless of crop type, in surface soils with high clay content. At depth, the response of the slow pool differed between annual and perennial cropping systems. The distribution of C among SOM fractions varied between the two soil types, with greater C content associated with the active fraction in the coarser textured-soil and greater C content associated with the slow-cycling fraction in the soils with high clay content. These results suggest that the effects of bioenergy crops on soil resources will vary geographically, with implications for the carbon-cost of biocrop production.

  13. The impact of roots on soil organic carbon dynamics in annual and perennial agricultural systems

    NASA Astrophysics Data System (ADS)

    Beniston, J.; Dupont, T.; Glover, J.; Lal, R.

    2012-12-01

    Identifying and developing agricultural systems capable of transferring large quantities of carbon (C) to the soil and sustaining ecosystem processes and services is a priority for ecological researchers and land managers. Temperate grasslands have extensive root systems and transfer large quantities of C to the soil organic C (SOC) pool, which has lead to widespread interest in utilizing perennial grasses as both bioenergy crops and as a model for perennial grains. This study examined five sites in north central Kansas (U.S.A.) that contain the unique land use pairing of tall grass prairie meadows (PM) that have been harvested annually for hay for the past 75 years and annual grain (wheat) production fields (AG) that have been cultivated for a similar length of time, all on deep alluvial soils. Specific research objectives included: 1) To quantify below-ground biomass pools and root C contributions in the two systems; 2) To analyze and compare SOC pools and SOC concentration in primary particle size fractions in the two systems; 3) To utilize natural abundance δ13C signatures to determine the source and turnover of SOC in the soils of the AG sites; and 4) To elucidate the relationship of roots to both SOC pools and nematode food webs. Soil core samples were collected to a depth of 1 m in May and June 2008. Soil samples were analyzed for SOC, microbial biomass C (MBC), nematodes, and a particle size fractionation of SOC in coarse (>250 μm), particulate organic matter (POM) (53-250 μm), silt (2-53 μm), and clay (<2 μm) sized fractions. Root biomass, root length and root C were also analyzed to a depth of 1 m. Natural abundance δ13C values were obtained for all C parameters. Soils under PM had 4 times as much root C as AG soils to 1 m depth in mid May (PM 2.8 Mg ha-1 and AG 0.7 Mg ha-1) and 7 times as much root C to 1 m depth in late June (PM 3.5 Mg ha-1 and AG 0.5 Mg ha-1). The MBC pools were significantly larger in grassland soils to a depth of 60 cm in May

  14. Soybean fungal soil-borne diseases: a parameter for measuring the effect of agricultural intensification on soil health.

    PubMed

    Pérez-Brandán, C; Huidobro, J; Grümberg, B; Scandiani, M M; Luque, A G; Meriles, J M; Vargas-Gil, S

    2014-02-01

    The aim of this study was to investigate the influence of agricultural intensification on soil microbial diversity, chemical and physical parameters, and the decrease of the incidence of sudden death syndrome (Fusarium crassistipitatum) and charcoal rot (Macrophomina phaseolina) in soybean. Soils under different management systems were evaluated during 2 crop cycles: soybean monoculture for 24 and 11 years, soybean-maize rotation for 15 and 4 years, 1 year of soybean, and native vegetation. The incidence of both soil-borne diseases was higher under monoculture than under rotation. Increased populations of potential biocontrol agents (Trichoderma spp., Gliocladium spp., fluorescent pseudomonads) were associated with rotation treatments, especially in 2010-2011. The comparison of agricultural vs. native vegetation soil and the average of agricultural cycles showed that microbial biomass carbon and glomalin-related soil protein were higher in the rotation system than in monoculture (50% and 77%, respectively). Furthermore, from the community-level functional diversity (Biolog Eco plates), McIntosh index showed lower functional diversity in monoculture than in rotation and native vegetation plots. Agricultural intensification reduced microbial biomass carbon, glomalin-related soil protein, organic matter, total nitrogen, aggregate stability, and yield, and increased bulk density. Soil quality degradation was associated with the establishment of soil-borne pathogens and increased soybean plant susceptibility to disease.

  15. Soybean fungal soil-borne diseases: a parameter for measuring the effect of agricultural intensification on soil health.

    PubMed

    Pérez-Brandán, C; Huidobro, J; Grümberg, B; Scandiani, M M; Luque, A G; Meriles, J M; Vargas-Gil, S

    2014-02-01

    The aim of this study was to investigate the influence of agricultural intensification on soil microbial diversity, chemical and physical parameters, and the decrease of the incidence of sudden death syndrome (Fusarium crassistipitatum) and charcoal rot (Macrophomina phaseolina) in soybean. Soils under different management systems were evaluated during 2 crop cycles: soybean monoculture for 24 and 11 years, soybean-maize rotation for 15 and 4 years, 1 year of soybean, and native vegetation. The incidence of both soil-borne diseases was higher under monoculture than under rotation. Increased populations of potential biocontrol agents (Trichoderma spp., Gliocladium spp., fluorescent pseudomonads) were associated with rotation treatments, especially in 2010-2011. The comparison of agricultural vs. native vegetation soil and the average of agricultural cycles showed that microbial biomass carbon and glomalin-related soil protein were higher in the rotation system than in monoculture (50% and 77%, respectively). Furthermore, from the community-level functional diversity (Biolog Eco plates), McIntosh index showed lower functional diversity in monoculture than in rotation and native vegetation plots. Agricultural intensification reduced microbial biomass carbon, glomalin-related soil protein, organic matter, total nitrogen, aggregate stability, and yield, and increased bulk density. Soil quality degradation was associated with the establishment of soil-borne pathogens and increased soybean plant susceptibility to disease. PMID:24498984

  16. Soil and geography are more important determinants of indigenous arbuscular mycorrhizal communities than management practices in Swiss agricultural soils.

    PubMed

    Jansa, Jan; Erb, Angela; Oberholzer, Hans-Rudolf; Smilauer, Petr; Egli, Simon

    2014-04-01

    Arbuscular mycorrhizal fungi (AMF) are ubiquitous soil fungi, forming mutualistic symbiosis with a majority of terrestrial plant species. They are abundant in nearly all soils, less diverse than soil prokaryotes and other intensively studied soil organisms and thus are promising candidates for universal indicators of land management legacies and soil quality degradation. However, insufficient data on how the composition of indigenous AMF varies along soil and landscape gradients have hampered the definition of baselines and effect thresholds to date. Here, indigenous AMF communities in 154 agricultural soils collected across Switzerland were profiled by quantitative real-time PCR with taxon-specific markers for six widespread AMF species. To identify the key determinants of AMF community composition, the profiles were related to soil properties, land management and site geography. Our results indicate a number of well-supported dependencies between abundances of certain AMF taxa and soil properties such as pH, soil fertility and texture, and a surprising lack of effect of available soil phosphorus on the AMF community profiles. Site geography, especially the altitude and large geographical distance, strongly affected AMF communities. Unexpected was the apparent lack of a strong land management effect on the AMF communities as compared to the other predictors, which could be due to the rarity of highly intensive and unsustainable land management in Swiss agriculture. In spite of the extensive coverage of large geographical and soil gradients, we did not identify any taxon suitable as an indicator of land use among the six taxa we studied.

  17. Some physicochemical properties of surface layer soils shelterbelts in agricultural landscape

    NASA Astrophysics Data System (ADS)

    Jaskulska, R.; Szajdak, L.

    2009-04-01

    Shelterbelts belong to very efficient biogeochemical barriers. They decrease the migration of chemical compounds between ecosystems. The investigations were carried out in the Chlapowski's Agroecological Park in Turew situated 40 km South-West of Poznań, Poland. This area is located on loamy soils, which contains 70% cultivated fields and 14% shelterbelts and small afforestations. The shelterbelts represent different ages and the content of plants as well as humus quantity in surface layer. The first one is 100-year-old shelterbelt, where predominant species is Crataegus monogyna Jacq., Quercus rober L., and Fraxinus excelsior (L.) and is characterized by a well-developed humus level. The other one is 14-year-old shelterbelt. It includes 13 species of trees and revealed a small amount of humus. The soil under both shelterbelts is mineral, grey-brown podzolic in surface layer compound from light loamy sands and weakly loamy sands. The soil samples were taken from surface layer (0-20 cm). pH 1N KCl, hydrolytic acidity, cation-exchange capacity, total proper area, total organic carbon and dissociation constants were determined in soils. The study showed that the soil under shelterbelts revealed acidic properties. It was observed that soils of 100-year-old shelterbelt characterizing lowest values pH = 4.2 revealed highest values of hydrolytic acidity equaled to 7.8 cmol(+)ṡkg-1. The physicochemical properties of investigated soils shoved specific surface areas (22.8 m2ṡg-1), cationic sorptive capacity (12.9 cmol(+)ṡkg-1). TOC (1.6%) 100-year-old shelterbelt was higher than in 14-year-old shelterbelt. The dissociation constants were determined by potentiometric titration. This investigation revealed that the pK value was the highest in the humus of 100-year-old shelterbelt (pKa = 3.1). However, soils of 14-year-old shelterbelt characterized by the lovest pK equaled to 2.8. The surface layer soils shelterbelts in agricultural landscape with good humus development

  18. Soil sampling sensor system on a mobile robot

    NASA Astrophysics Data System (ADS)

    Cao, Peter M.; Hall, Ernest L.; Zhang, Evan

    2003-10-01

    Determining if a segment of property is suitable for use as an aircraft is a vitally important task that is currently performed by humans. However, this task can also put our people in harms way from land mines, sniper and artillery attacks. The objective of this research is to build a soil survey manipulator that can be carried by a lightweight, portable, autonomous vehicle, sensors and controls to navigate in assault zone. The manipulators permit both surface and sub surface measurements. An original soil sampling tube was constructed with linear actuator as manipulator and standard penetrometer as sampling sensor. The controls provide local control of the robot as well as the soil sampling mechanism. GPS has been selected to perform robot global navigation. The robot was constructed and tested on the test field. The results verified the concepts of using soil sampling robot to survey runway is feasible.

  19. Analysis of bioavailable Ge in agricultural and mining-affected-soils in Freiberg area (Saxony, Germany)

    NASA Astrophysics Data System (ADS)

    Wiche, Oliver; Székely, Balázs; Kummer, Nicolai-Alexeji; Heinemann, Ute; Heilmeier, Hermann

    2014-05-01

    Germanium (Ge) concentrations in different soil fraction were investigated using a sequential selective dissolution analysis and a rhizosphere-based single-step extraction method for the identification of Ge-bearing soil fractions and prediction of bioavailability of Ge in soil to plants. About 50 soil samples were collected from various soil depths (horizons A and B) and study sites with different types of land use (dry and moist grassland, arable land, mine dumps) in Freiberg area (Saxony, Germany). Ge has been extracted in six soil fractions: mobile fraction, organic matter and sulfides, Mn- and Fe-oxides (amorphous and crystalline), and kaolinite and phytoliths, and residual fraction. The rhizosphere-based method included a 7-day-long extraction sequence with various organic acids like citric acid, malic acid and acetic acid. For the residue the aforementioned sequential extraction has been applied. The Ge-content of the samples have been measured with ICP-MS using rhodium internal standard and two different soil standards. Total Ge concentrations were found to be in the range of 1.6 to 5.5 ppm with highest concentrations on the tailing site in the mining area of Altenberg. The mean Ge concentration in agriculturally used soils was 2.6 ± 0.67 ppm, whereas the maximum values reach 2.9 ± 0.64 ppm and 3.2 ± 0.67 ppm in Himmelsfürst and in a grassland by the Mulde river, respectively. With respect to the fractions, the vast majority of Ge is contained in the last three fractions, indicating that the bioavailable Ge is typically low in the samples. On the other hand at the soil horizons A at the aforementioned two sites characterised by high total Ge, together with that of Reiche Zeche mine dump have also the highest concentrations of Ge in the first three fractions, reaching levels of 1.74 and 0.98 ppm which account for approximately 40% of the total Ge content. Ge concentrations of soil samples extracted with 0.01 or 0.1 M citric acid and malic acid were

  20. Soil sample collection and analysis for the Fugitive Dust Characterization Study

    NASA Astrophysics Data System (ADS)

    Ashbaugh, Lowell L.; Carvacho, Omar F.; Brown, Michael S.; Chow, Judith C.; Watson, John G.; Magliano, Karen C.

    A unique set of soil samples was collected as part of the Fugitive Dust Characterization Study. The study was carried out to establish whether or not source profiles could be constructed using novel analytical methods that could distinguish soil dust sources from each other. The soil sources sampled included fields planted in cotton, almond, tomato, grape, and safflower, dairy and feedlot facilities, paved and unpaved roads (both urban and rural), an agricultural staging area, disturbed land with salt buildup, and construction areas where the topsoil had been removed. The samples were collected using a systematic procedure designed to reduce sampling bias, and were stored frozen to preserve possible organic signatures. For this paper the samples were characterized by particle size (percent sand, silt, and clay), dry silt content (used in EPA-recommended fugitive dust emission factors), carbon and nitrogen content, and potential to emit both PM 10 and PM 2.5. These are not the "novel analytical methods" referred to above; rather, it was the basic characterization of the samples to use in comparing analytical methods by other scientists contracted to the California Air Resources Board. The purpose of this paper is to document the methods used to collect the samples, the collection locations, the analysis of soil type and potential to emit PM 10, and the sample variability, both within field and between fields of the same crop type.

  1. Occurrences and toxicological risk assessment of eight heavy metals in agricultural soils from Kenya, Eastern Africa.

    PubMed

    Mungai, Teresiah Muciku; Owino, Anita Awino; Makokha, Victorine Anyango; Gao, Yan; Yan, Xue; Wang, Jun

    2016-09-01

    The concentration distribution and toxicological assessment of eight heavy metals including lead (Pb), cadmium (Cd), copper (Cu), chromium (Cr), nickel (Ni), mercury (Hg), arsenic (As), and zinc (Zn) in agricultural soils from Kenya, Eastern Africa, were investigated in this study. The results showed mean concentrations of eight heavy metals of Zn, Pb, Cr, Cu, As, Ni, Hg, and Cd in agricultural soils as 247.39, 26.87, 59.69, 88.59, 8.93, 12.56, 8.06, and 0.42 mg kg(-1), respectively. These mean values of eight heavy metals were close to the toxicity threshold limit of USEPA standard values of agricultural soils, indicating potential toxicological risk to the food chain. Pollution index values revealed that eight heavy metals severely decreased in the order Hg > Cd > As > Cu > Pb > Zn > Ni > Cr and the mean value of the overall pollution index of Hg and Cd was 20.31, indicating severe agriculture ecological risk. Potential pollution sources of eight heavy metals in agricultural soils were mainly from anthropogenic activities and natural dissolution. The intensification of human agricultural activities, the growing industrialization, and the rapid urbanization largely influenced the concentration levels of heavy metals in Kenya, Eastern Africa. Moreover, the lack of agricultural normalization management and poor enforcement of environmental laws and regulations further intensified the widespread pollution of agricultural soils in Kenya. PMID:27291978

  2. Changes in Soil Chemistry and Agricultural Return Flow in an Integrated Seawater Agriculture System (ISAS) Demonstration in Abu Dhabi

    NASA Astrophysics Data System (ADS)

    Ning, Q.; Matiin, W. A.; Ahmad, F.

    2012-12-01

    Growing halophytes using Integrated Seawater Agriculture Systems (ISAS) offers a sustainable solution for the generation of biomass feedstock for carbon neutral biofuels - halophytes do not enter the foodchain and they do not compete with food-crops for natural resources. A field demonstration of ISAS in the coastal regions of Abu Dhabi, UAE, scheduled to start in 2013, will likely face a number of region-specific challenges not encountered in past demonstrations of ISAS at coastal locations in Mexico and Eritrea. The arid climate, unique soil chemistry (evaporite deposits, especially gypsum), and hypersaline coastal hydrogeology of Abu Dhabi will affect long-term halophyte agricultural productivity when Arabian Gulf seawater is applied to coastal soils as part of ISAS. Therefore, the changes in irrigation return flow quality and soil chemistry must be monitored closely over time to establish transient salt and water balances in order to assess the sustainability of ISAS in the region. As an initial phase of the ISAS demonstration project, numerical modeling of different seawater loadings onto coastal soils was conducted to estimate the chemical characteristics of soil and the irrigation return flow over time. These modeling results will be validated with field monitoring data upon completion of one year of ISAS operation. The results from this study could be used to (i) determine the optimal saline water loading that the soils at the ISAS site can tolerate, (ii) potential for sodicity of the soil with saline water application, (iii) impacts of land application of saline water on underlying coastal groundwater, and (iv) develop strategies to control soil water activities in favor of halophyte agricultural productivity.

  3. Mineralogy of agricultural soil of selected regions of South Western Karnataka, Peninsular India.

    PubMed

    Smitha, P G; Byrappa, K; Ranganathaiah, C

    2015-07-01

    Agricultural soils of selected regions of Southwestern Karnataka, Peninsular India, were subjected to systematic mineralogical characterization along with the study of soil physical properties. Physical properties such as soil texture and micro porosity were studied using particle size analyses and positron annihilation lifetime analysis (PALS) technique, respectively. The latter was used to analyze micro porosity of agricultural soil. Both major and minor minerals were identified and confirmed by some analytical techniques like thin section study, powder X-ray diffraction, X-ray fluorescence spectroscopy and Fourier transform infrared spectroscopy.

  4. Impact of woodchip biochar amendment on the sorption and dissipation of pesticide acetamiprid in agricultural soils.

    PubMed

    Yu, Xiang-Yang; Mu, Chang-Li; Gu, Cheng; Liu, Cun; Liu, Xian-Jin

    2011-11-01

    Pyrolysis of vegetative biomass into biochar and application of the more stable form of carbon to soil have been shown to be effective in reducing the emission of greenhouse gases, improving soil fertility, and sequestering soil contaminants. However, there is still lack of information about the impact of biochar amendment in agricultural soils on the sorption and environmental fate of pesticides. In this study, we investigated the sorption and dissipation of a neonicotinoid insecticide acetamiprid in three typical Chinese agricultural soils, which were amended by a red gum wood (Eucalyptus spp.) derived biochar. Our results showed that the amendment of biochar (0.5% (w/w)) to the soils could significantly increase the sorption of acetamiprid, but the magnitudes of enhancement were varied. Contributions of 0.5% newly-added biochar to the overall sorption of acetamiprid were 52.3%, 27.4% and 11.6% for red soil, paddy soil and black soil, respectively. The dissipation of acetamiprid in soils amended with biochar was retarded compared to that in soils without biochar amendment. Similar to the sorption experiment, in soil with higher content of organic matter, the retardation of biochar on the dissipation of acetamiprid was lower than that with lower content of organic matter. The different effects of biochar in agricultural soils may attribute to the interaction of soil components with biochar, which would block the pore or compete for binding site of biochar. Aging effect of biochar application in agricultural soils and field experiments need to be further investigated. PMID:21862101

  5. Phytoremediation of soil polluted by nickel using agricultural crops.

    PubMed

    Giordani, Cesare; Cecchi, Stefano; Zanchi, Camillo

    2005-11-01

    Soil pollution due to heavy metals is widespread; on the world scale, it involves about 235 million hectares. The objectives of this research were to establish the uptake efficiency of nickel by some agricultural crops. In addition, we wanted to establish also in which part of plants the metal is stored for an eventual use of biomass or for recycling the metal. The experiments included seven herbaceous crops such as: barley (Hordeum vulgaris), cabbage (Brassica juncea), spinach (Spinacea oleracea), sorghum (Sorgum vulgare), bean (Phaseolus vulgaris), tomato (Solanum lycopersicum), and ricinus (Ricinus communis). We used three levels of treatment (150, 300, and 600 ppm) and one control. At the end of the biological cycle of the crops, the different parts of plants, i.e., roots, stems, leaves, fruits, or seeds, were separately collected, oven dried, weighed, milled, and separately analysed. The leaves and stems of spinach showed a very good nickel storage capacity. The ricinus too proved to be a very good nickel storer. The ability of spinach and ricinus to store nickel was observed also in the leaves of cabbage, even if with a lower storage capacity. The bean, barley, and tomato, in decreasing order of uptake and storage capacity, showed a high concentration of nickel in leaves and stems, whereas the sorghum evidenced a lesser capacity to uptake and store nickel in leaves and stems. The bean was the most efficient in storing nickel in fruits or grains. Tomato, sorghum, and barley have shown a storage capacity notably less than bean. The bean appeared to be the most efficient in accumulating nickel in the roots, followed in decreasing order by sorghum, ricinus, and tomato. With regard to the removal of nickel, spinach was the most efficient as it contains the highest level of this metal per gram of dry matter. The ricinus, cabbage, bean, sorghum, barley, and tomato evidenced a progressively decreasing efficiency in the removal of nickel.

  6. Phytoremediation of soil polluted by nickel using agricultural crops.

    PubMed

    Giordani, Cesare; Cecchi, Stefano; Zanchi, Camillo

    2005-11-01

    Soil pollution due to heavy metals is widespread; on the world scale, it involves about 235 million hectares. The objectives of this research were to establish the uptake efficiency of nickel by some agricultural crops. In addition, we wanted to establish also in which part of plants the metal is stored for an eventual use of biomass or for recycling the metal. The experiments included seven herbaceous crops such as: barley (Hordeum vulgaris), cabbage (Brassica juncea), spinach (Spinacea oleracea), sorghum (Sorgum vulgare), bean (Phaseolus vulgaris), tomato (Solanum lycopersicum), and ricinus (Ricinus communis). We used three levels of treatment (150, 300, and 600 ppm) and one control. At the end of the biological cycle of the crops, the different parts of plants, i.e., roots, stems, leaves, fruits, or seeds, were separately collected, oven dried, weighed, milled, and separately analysed. The leaves and stems of spinach showed a very good nickel storage capacity. The ricinus too proved to be a very good nickel storer. The ability of spinach and ricinus to store nickel was observed also in the leaves of cabbage, even if with a lower storage capacity. The bean, barley, and tomato, in decreasing order of uptake and storage capacity, showed a high concentration of nickel in leaves and stems, whereas the sorghum evidenced a lesser capacity to uptake and store nickel in leaves and stems. The bean was the most efficient in storing nickel in fruits or grains. Tomato, sorghum, and barley have shown a storage capacity notably less than bean. The bean appeared to be the most efficient in accumulating nickel in the roots, followed in decreasing order by sorghum, ricinus, and tomato. With regard to the removal of nickel, spinach was the most efficient as it contains the highest level of this metal per gram of dry matter. The ricinus, cabbage, bean, sorghum, barley, and tomato evidenced a progressively decreasing efficiency in the removal of nickel. PMID:16215654

  7. Response of Soil Properties and Microbial Communities to Agriculture: Implications for Primary Productivity and Soil Health Indicators.

    PubMed

    Trivedi, Pankaj; Delgado-Baquerizo, Manuel; Anderson, Ian C; Singh, Brajesh K

    2016-01-01

    Agricultural intensification is placing tremendous pressure on the soil's capacity to maintain its functions leading to large-scale ecosystem degradation and loss of productivity in the long term. Therefore, there is an urgent need to find early indicators of soil health degradation in response to agricultural management. In recent years, major advances in soil meta-genomic and spatial studies on microbial communities and community-level molecular characteristics can now be exploited as 'biomarker' indicators of ecosystem processes for monitoring and managing sustainable soil health under global change. However, a continental scale, cross biome approach assessing soil microbial communities and their functional potential to identify the unifying principles governing the susceptibility of soil biodiversity to land conversion is lacking. We conducted a meta-analysis from a dataset generated from 102 peer-reviewed publications as well as unpublished data to explore how properties directly linked to soil nutritional health (total C and N; C:N ratio), primary productivity (NPP) and microbial diversity and composition (relative abundance of major bacterial phyla determined by next generation sequencing techniques) are affected in response to agricultural management across the main biomes of Earth (arid, continental, temperate and tropical). In our analysis, we found strong statistical trends in the relative abundance of several bacterial phyla in agricultural (e.g., Actinobacteria and Chloroflexi) and natural (Acidobacteria, Proteobacteria, and Cyanobacteria) systems across all regions and these trends correlated well with many soil properties. However, main effects of agriculture on soil properties and productivity were biome-dependent. Our meta-analysis provides evidence on the predictable nature of the microbial community responses to vegetation type. This knowledge can be exploited in future for developing a new set of indicators for primary productivity and soil

  8. Major pollutants in soils of abandoned agricultural land contaminated by e-waste activities in Hong Kong.

    PubMed

    Lopez, Brenda Natalia; Man, Yu Bon; Zhao, Yin Ge; Zheng, Jin Shu; Leung, Anna Oi Wah; Yao, Jun; Wong, Ming Hung

    2011-07-01

    Polycyclic aromatic hydrocarbon (PAH), polychlorinated biphenyl (PCB), polybrominated diphenyl ether (PBDE) compounds and five heavy metals (cadmium, copper, chromium, lead, and zinc) were determined in soil samples collected from six sites of abandoned agricultural land affected by electronic-waste: e-waste dismantling workshop [EW (DW)], e-waste open burning site [EW (OBS)], e-waste storage [EW (S)], and agricultural (A) in the New Territories, Hong Kong. Persistent organic pollutants (POPs) and heavy metals were detected in all soil samples. EW (DW) contained the highest concentrations of PAHs, Cr, Cu, and Zn, whereas EW (OBS) had the highest concentrations of PCBs, PBDEs, Cd, and Pb. PAH at EW (DW) and EW (OBS) and PCB concentrations at EW (OBS) exceeded the target values of the New Dutch list, whereas Cd, Cu, Cr, Pb, and Zn levels exceeded the Chinese legislation for the protection of agricultural production and safeguarding of human health, by 3-11 times at EW (OBS) and 5-8 times at EW (DW). Lead at EW (OBS) and EW (DW) and Cr at EW (DW) greatly exceeded the Canadian Soil Quality Guidelines by 46 and 20 times and 27 times, respectively. Concentrations of POPs and heavy metals at EW (DW) and EW (OBS) were significantly higher than at EW (S) and A. It was concluded that e-waste activities led to increases of toxic chemicals at these abandoned agricultural land, which would hinder the redevelopment of the land. PMID:20811881

  9. Major pollutants in soils of abandoned agricultural land contaminated by e-waste activities in Hong Kong.

    PubMed

    Lopez, Brenda Natalia; Man, Yu Bon; Zhao, Yin Ge; Zheng, Jin Shu; Leung, Anna Oi Wah; Yao, Jun; Wong, Ming Hung

    2011-07-01

    Polycyclic aromatic hydrocarbon (PAH), polychlorinated biphenyl (PCB), polybrominated diphenyl ether (PBDE) compounds and five heavy metals (cadmium, copper, chromium, lead, and zinc) were determined in soil samples collected from six sites of abandoned agricultural land affected by electronic-waste: e-waste dismantling workshop [EW (DW)], e-waste open burning site [EW (OBS)], e-waste storage [EW (S)], and agricultural (A) in the New Territories, Hong Kong. Persistent organic pollutants (POPs) and heavy metals were detected in all soil samples. EW (DW) contained the highest concentrations of PAHs, Cr, Cu, and Zn, whereas EW (OBS) had the highest concentrations of PCBs, PBDEs, Cd, and Pb. PAH at EW (DW) and EW (OBS) and PCB concentrations at EW (OBS) exceeded the target values of the New Dutch list, whereas Cd, Cu, Cr, Pb, and Zn levels exceeded the Chinese legislation for the protection of agricultural production and safeguarding of human health, by 3-11 times at EW (OBS) and 5-8 times at EW (DW). Lead at EW (OBS) and EW (DW) and Cr at EW (DW) greatly exceeded the Canadian Soil Quality Guidelines by 46 and 20 times and 27 times, respectively. Concentrations of POPs and heavy metals at EW (DW) and EW (OBS) were significantly higher than at EW (S) and A. It was concluded that e-waste activities led to increases of toxic chemicals at these abandoned agricultural land, which would hinder the redevelopment of the land.

  10. Soil biota community structure and abundance under agricultural intensification and extensification.

    PubMed

    Postma-Blaauw, Maria B; de Goede, Ron G M; Bloem, Jaap; Faber, Jack H; Brussaard, Lijbert

    2010-02-01

    Understanding the impacts of agricultural intensification and extensification on soil biota communities is useful in order to preserve and restore biological diversity in agricultural soils and enhance the role of soil biota in agroecosystem functioning. Over four consecutive years, we investigated the effects of agricultural intensification and extensification (including conversion of grassland to arable land and vice versa, increased and decreased levels of mineral fertilization, and monoculture compared to crop rotation) on major soil biota group abundances and functional diversity. We integrated and compared effects across taxonomic levels to identify sensitive species groups. Conversion of grassland to arable land negatively affected both abundances and functional diversity of soil biota. Further intensification of the cropping system by increased fertilization and reduced crop diversity exerted smaller and differential effects on different soil biota groups. Agricultural intensification affected abundances of taxonomic groups with larger body size (earthworms, enchytraeids, microarthropods, and nematodes) more negatively than smaller-sized taxonomic groups (protozoans, bacteria, and fungi). Also functional group diversity and composition were more negatively affected in larger-sized soil biota (earthworms, predatory mites) than in smaller-sized soil biota (nematodes). Furthermore, larger soil biota appeared to be primarily affected by short-term consequences of conversion (disturbance, loss of habitat), whereas smaller soil biota were predominantly affected by long-term consequences (probably loss of organic matter). Reestablishment of grassland resulted in increased abundances of soil biota groups, but since not all groups increased in the same measure, the community structure was not completely restored. We concluded that larger-sized soil biota are more sensitive to agricultural intensification than smaller-sized soil biota. Furthermore, since larger

  11. Occurrence of organic chlorinated pesticides and their ecological effects on soil protozoa in the agricultural soils of North Western Beijing, China.

    PubMed

    Shi, Yajuan; Lu, Yonglong; Meng, Fanqiao; Guo, Feifan; Zheng, Xiaoqi

    2013-06-01

    The occurrence of ∑HCHs, ∑DDTs, protozoa abundance and their community structure in surface soils of orchards, vegetable lands, and barren lands in northern west outskirts of Beijing were detected in order to investigate the protozoa responses to low dose organic chlorinated Pesticides (OCPs) after long-term field-based exposure. Significant differences in total concentrations of HCHs and DDTs were found among the three general groups ranking in decreasing order of concentration from orchard>vegetable lands >barren lands. Ciliate was the rare group in surface soils of all the sampling groups. The abundance of flagellate, ciliate, and amoebae in vegetable soils were significantly higher than those in orchard soils. The abundance of all the taxa of protozoa was strongly negative correlated with the residue level of ∑HCHs and ∑DDTs (P<0.05) in agricultural soils. However, no negative correlation between the residue levels of OCPs and protozoa abundance was shown in both the orchard and the barren soils. This field study demonstrated a considerable long-term impact of the OCPs residue on the abundance of protozoa in soils, and that the abundance of soil protozoa was much more influenced by land use type in association with different soil properties. PMID:23582133

  12. Occurrence of organic chlorinated pesticides and their ecological effects on soil protozoa in the agricultural soils of North Western Beijing, China.

    PubMed

    Shi, Yajuan; Lu, Yonglong; Meng, Fanqiao; Guo, Feifan; Zheng, Xiaoqi

    2013-06-01

    The occurrence of ∑HCHs, ∑DDTs, protozoa abundance and their community structure in surface soils of orchards, vegetable lands, and barren lands in northern west outskirts of Beijing were detected in order to investigate the protozoa responses to low dose organic chlorinated Pesticides (OCPs) after long-term field-based exposure. Significant differences in total concentrations of HCHs and DDTs were found among the three general groups ranking in decreasing order of concentration from orchard>vegetable lands >barren lands. Ciliate was the rare group in surface soils of all the sampling groups. The abundance of flagellate, ciliate, and amoebae in vegetable soils were significantly higher than those in orchard soils. The abundance of all the taxa of protozoa was strongly negative correlated with the residue level of ∑HCHs and ∑DDTs (P<0.05) in agricultural soils. However, no negative correlation between the residue levels of OCPs and protozoa abundance was shown in both the orchard and the barren soils. This field study demonstrated a considerable long-term impact of the OCPs residue on the abundance of protozoa in soils, and that the abundance of soil protozoa was much more influenced by land use type in association with different soil properties.

  13. Determination of bioavailable macro- and microelements from agricultural soil using different extractants

    NASA Astrophysics Data System (ADS)

    Milićević, Tijana; Relić, Dubravka; Popović, Aleksandar

    2015-04-01

    Translocation of elements from soil to plant has a major impact on the growing plants and on their quality in any agricultural field. In this study, soil samples were collected from agricultural area Radmilovac, Serbia during grapevine season in 2013. Bioavailable elements from soil to plant (grapevine) were isolated by five different extractants: 0.11 mol L-1 CH3COOH, 0.05 mol L-1 Na-EDTA, 0.01 mol L-1 CaCl2, 1 mol L-1 NH4NO3 and distilled water during 2 and 16 h. Concentrations of 22 bioavailable macroelements: Al, Ca, Fe, K, Mg, Mn, Na, P, S, Si and microelements: B, Be, Cd, Co, Cr, Cu, Mo, Ni, Pb, Sb, V, Zn were determined by ICP-OES. The best extractant for Al, B, Be, Mg, Mo, Si and Zn was CH3COOH, Na-EDTA for Ca, Cd, Co, Cu, Fe, K, Mn, Ni, P, Pb, V, and distilled water for Na and S. Acetic acid has been proven to be an aggressive extractant and it can be used for isolation of higher concentrations of plant bioavailable elements from soil, rather than distilled water, CaCl2 and NH4NO3. The acidity of CH3COOH enhances the extraction of bioavailable fraction of microelements from various substrates and destruction of carbonates as well. However, it can be concluded that there is no unique extractant for isolation of the most bioavailable fraction for all elements from the soil. It can be noticed that the most common concentrations of macroelements, K and Mn, are in correlation with concentrations of microelements, Cd, Co, Ni and Zn. This indicates that the most of their concentrations in soils are followed by microelements, whose concentrations are much lower than concentrations of macroelements. However, as these correlations are the most common, it can be concluded that the pairs of macro- and microelements (e.g. Mn-Cd, Mn-Co, Ni-Cd, Ni-Co, Ni-Mn, Zn-Cd, Zn-Co, Zn-Mn, Zn-Ni) have the same source in soil and can be isolated by the same extractant. It is interesting to note that the concentrations of Ca and Mg extracted from soil using CH3COOH are in correlation

  14. Prehistoric Agriculture and Soil Fertility on Lava Flows in Northern Arizona, USA: Results from the San Francisco Volcanic Field REU

    NASA Astrophysics Data System (ADS)

    Broadman, E.; Anderson, K. C.

    2013-12-01

    The San Francisco Volcanic Field in northern Arizona is home to ~600 cinder cones, the youngest of which is Sunset Crater (erupted ~AD 1100). This study documents trends in available phosphate and nitrate content with time, testing whether lowered soil pH from the addition of Sunset cinders increased soil fertility and became a factor in Anasazi agricultural success. Soil fertility is examined both before and after Sunset's eruption in soils of different ages that have developed from eolian deposition on top of lava flows. An increase in phosphate and nitrate levels following acidification would suggest that the presence of Sunset cinders brought the soils to the optimal pH for mobilization of these nutrients. The combined effects of the cinder layer retaining nutrients and water, wetter climates, and increases in phosphate and nitrate (both limiting nutrients for plant growth), would have contributed to Anasazi agricultural success after Sunset's eruption. Samples for this study were taken from eolian-derived soils of different ages atop lava flows in the San Francisco Volcanic Field. OSL data from these soils on Strawberry and SP Craters' lava flows yielded age estimates of ~12.3 ka (Strawberry) and ~32.7 ka (SP), on which a soil chronosequence was based. Results from the chronosequence supported these OSL ages, indicating that soils on the SP flow are older than those on the Strawberry flow. Field descriptions, Harden Development Indices, particle size analysis, and nutrient content analysis were used for this aspect of the project. An experimental acid wash method will be used to simulate the addition of Sunset's acidic cinders, and will yield data for phosphate and nitrate content after Sunset erupted. Preliminary results indicate that phosphate and nitrate accumulate in upper, eolian-derived horizons (Av, Bw) and in more deeply buried carbonate horizons (Bk). Higher concentrations of phosphate and nitrate were found in older (SP) soils than younger

  15. Soil microbial community response to land use change in an agricultural landscape of western Kenya.

    PubMed

    Bossio, D A; Girvan, M S; Verchot, L; Bullimore, J; Borelli, T; Albrecht, A; Scow, K M; Ball, A S; Pretty, J N; Osborn, A M

    2005-01-01

    Tropical agroecosystems are subject to degradation processes such as losses in soil carbon, nutrient depletion, and reduced water holding capacity that occur rapidly resulting in a reduction in soil fertility that can be difficult to reverse. In this research, a polyphasic methodology has been used to investigate changes in microbial community structure and function in a series of tropical soils in western Kenya. These soils have different land usage with both wooded and agricultural soils at Kakamega and Ochinga, whereas at Ochinga, Leuro, Teso, and Ugunja a replicated field experiment compared traditional continuous maize cropping against an improved N-fixing fallow system. For all sites, principal component analysis of 16S rRNA gene denaturing gradient gel electrophoresis (DGGE) profiles revealed that soil type was the key determinant of total bacterial community structure, with secondary variation found between wooded and agricultural soils. Similarly, phospholipid fatty acid (PLFA) analysis also separated wooded from agricultural soils, primarily on the basis of higher abundance of monounsaturated fatty acids, anteiso- and iso-branched fatty acids, and methyl-branched fatty acids in the wooded soils. At Kakamega and Ochinga wooded soils had between five 5 and 10-fold higher levels of soil carbon and microbial biomass carbon than agricultural soils from the same location, whereas total enzyme activities were also lower in the agricultural sites. Soils with woody vegetation had a lower percentage of phosphatase activity and higher cellulase and chitinase activities than the agricultural soils. BIOLOG analysis showed woodland soils to have the greatest substrate diversity. Throughout the study the two functional indicators (enzyme activity and BIOLOG), however, showed lower specificity with respect to soil type and land usage than did the compositional indicators (DGGE and PLFA). In the field experiment comparing two types of maize cropping, both the maize yields

  16. Sorption-desorption of indaziflam in selected agricultural soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sorption and desorption of indaziflam in 6 soils from Brazil and 3 soils from the USA, with different physical chemical properties, were investigated using the batch equilibration method. Sorption kinetics demonstrated that soil-solution equilibrium was attained in a 24-h period. The Freundlich equa...

  17. Estimation of PCB content in agricultural soils associated with long-term fertilization with organic waste.

    PubMed

    Antolín-Rodríguez, Juan M; Sánchez-Báscones, Mercedes; Martín-Ramos, Pablo; Bravo-Sánchez, Carmen T; Martín-Gil, Jesús

    2016-06-01

    Polychlorinated biphenyl (PCB) pollution related to the use of organic waste as fertilizers in agricultural soils is a cause of major concern. In the study presented herein, PCB concentration was studied through a field trial conducted in two agricultural soils in the province of Palencia (Spain) over a 4-year period, assessing the impact of irrigation and of different types of organic waste materials. The amounts of organic waste added to the soil were calculated according to the nitrogen needs of the crop, and the concentration of PCBs was determined before and after the application of the organic waste. The resulting persistence of the total PCB content in the agricultural soils, compared with the PCB concentration in the original soils, ranged from 27% to 90%, with the lowest value corresponding to irrigated soils treated with municipal solid waste compost (MSWC) and the highest value to non-irrigated soils treated with composted sewage sludge (CSS). An estimate of the PCB content in agricultural soils after the application of organic waste materials until year 2050 was obtained, resulting in a value below 5 ng·g(-1), considered a background value for soils in sites far away from potential pollution sources. PMID:26983809

  18. Organic matter composition of soil macropore surfaces under different agricultural management practices

    NASA Astrophysics Data System (ADS)

    Glæsner, Nadia; Leue, Marin; Magid, Jacob; Gerke, Horst H.

    2016-04-01

    Understanding the heterogeneous nature of soil, i.e. properties and processes occurring specifically at local scales is essential for best managing our soil resources for agricultural production. Examination of intact soil structures in order to obtain an increased understanding of how soil systems operate from small to large scale represents a large gap within soil science research. Dissolved chemicals, nutrients and particles are transported through the disturbed plow layer of agricultural soil, where after flow through the lower soil layers occur by preferential flow via macropores. Rapid movement of water through macropores limit the contact between the preferentially moving water and the surrounding soil matrix, therefore contact and exchange of solutes in the water is largely restricted to the surface area of the macropores. Organomineral complex coated surfaces control sorption and exchange properties of solutes, as well as availability of essential nutrients to plant roots and to the preferentially flowing water. DRIFT (Diffuse Reflectance infrared Fourier Transform) Mapping has been developed to examine composition of organic matter coated macropores. In this study macropore surfaces structures will be determined for organic matter composition using DRIFT from a long-term field experiment on waste application to agricultural soil (CRUCIAL, close to Copenhagen, Denmark). Parcels with 5 treatments; accelerated household waste, accelerated sewage sludge, accelerated cattle manure, NPK and unfertilized, will be examined in order to study whether agricultural management have an impact on the organic matter composition of intact structures.

  19. Estimation of PCB content in agricultural soils associated with long-term fertilization with organic waste.

    PubMed

    Antolín-Rodríguez, Juan M; Sánchez-Báscones, Mercedes; Martín-Ramos, Pablo; Bravo-Sánchez, Carmen T; Martín-Gil, Jesús

    2016-06-01

    Polychlorinated biphenyl (PCB) pollution related to the use of organic waste as fertilizers in agricultural soils is a cause of major concern. In the study presented herein, PCB concentration was studied through a field trial conducted in two agricultural soils in the province of Palencia (Spain) over a 4-year period, assessing the impact of irrigation and of different types of organic waste materials. The amounts of organic waste added to the soil were calculated according to the nitrogen needs of the crop, and the concentration of PCBs was determined before and after the application of the organic waste. The resulting persistence of the total PCB content in the agricultural soils, compared with the PCB concentration in the original soils, ranged from 27% to 90%, with the lowest value corresponding to irrigated soils treated with municipal solid waste compost (MSWC) and the highest value to non-irrigated soils treated with composted sewage sludge (CSS). An estimate of the PCB content in agricultural soils after the application of organic waste materials until year 2050 was obtained, resulting in a value below 5 ng·g(-1), considered a background value for soils in sites far away from potential pollution sources.

  20. Soil respiration characteristics in different land uses and response of soil organic carbon to biochar addition in high-latitude agricultural area.

    PubMed

    Ouyang, Wei; Geng, Xiaojun; Huang, Wejia; Hao, Fanghua; Zhao, Jinbo

    2016-02-01

    The farmland tillage practices changed the soil chemical properties, which also impacted the soil respiration (R s ) process and the soil carbon conservation. Originally, the farmland in northeast China had high soil carbon content, which was decreased in the recent decades due to the tillage practices. To better understand the R s dynamics in different land use types and its relationship with soil carbon loss, soil samples at two layers (0-15 and 15-30 cm) were analyzed for organic carbon (OC), total nitrogen (TN), total phosphorus (TP), total carbon (TC), available nitrogen (AN), available phosphorus (AP), soil particle size distribution, as well as the R s rate. The R s rate of the paddy land was 0.22 (at 0-15 cm) and 3.01 (at 15-30 cm) times of the upland. The average concentrations of OC and clay content in cultivated areas were much lower than in non-cultivated areas. The partial least squares analysis suggested that the TC and TN were significantly related to the R s process in cultivated soils. The upland soil was further used to test soil CO2 emission response at different biochar addition levels during 70-days incubation. The measurement in the limited incubation period demonstrated that the addition of biochar improved the soil C content because it had high concentration of pyrogenic C, which was resistant to mineralization. The analysis showed that biochar addition can promote soil OC by mitigating carbon dioxide (CO2) emission. The biochar addition achieved the best performance for the soil carbon conservation in high-latitude agricultural area due to the originally high carbon content.

  1. Soil respiration characteristics in different land uses and response of soil organic carbon to biochar addition in high-latitude agricultural area.

    PubMed

    Ouyang, Wei; Geng, Xiaojun; Huang, Wejia; Hao, Fanghua; Zhao, Jinbo

    2016-02-01

    The farmland tillage practices changed the soil chemical properties, which also impacted the soil respiration (R s ) process and the soil carbon conservation. Originally, the farmland in northeast China had high soil carbon content, which was decreased in the recent decades due to the tillage practices. To better understand the R s dynamics in different land use types and its relationship with soil carbon loss, soil samples at two layers (0-15 and 15-30 cm) were analyzed for organic carbon (OC), total nitrogen (TN), total phosphorus (TP), total carbon (TC), available nitrogen (AN), available phosphorus (AP), soil particle size distribution, as well as the R s rate. The R s rate of the paddy land was 0.22 (at 0-15 cm) and 3.01 (at 15-30 cm) times of the upland. The average concentrations of OC and clay content in cultivated areas were much lower than in non-cultivated areas. The partial least squares analysis suggested that the TC and TN were significantly related to the R s process in cultivated soils. The upland soil was further used to test soil CO2 emission response at different biochar addition levels during 70-days incubation. The measurement in the limited incubation period demonstrated that the addition of biochar improved the soil C content because it had high concentration of pyrogenic C, which was resistant to mineralization. The analysis showed that biochar addition can promote soil OC by mitigating carbon dioxide (CO2) emission. The biochar addition achieved the best performance for the soil carbon conservation in high-latitude agricultural area due to the originally high carbon content. PMID:26408119

  2. The non-steroidal anti-inflammatory drug diclofenac is readily biodegradable in agricultural soils.

    PubMed

    Al-Rajab, Abdul Jabbar; Sabourin, Lyne; Lapen, David R; Topp, Edward

    2010-12-01

    Diclofenac, 2-[2-[(2,6-dichlorophenyl)amino]phenyl]acetic acid, is an important non-steroidal anti-inflammatory drug widely used for human and animals to reduce inflammation and pain. Diclofenac could potentially reach agricultural lands through the application of municipal biosolids or wastewater, and in the absence of any environmental fate data, we evaluated its persistence in agricultural soils incubated in the laboratory. (14)C-Diclofenac was rapidly mineralized without a lag when added to soils varying widely in texture (sandy loam, loam, clay loam). Over a range of temperature and moisture conditions extractable (14)C-diclofenac residues decreased with half lives <5days. No extractable transformation products were detectable by HPLC. Diclofenac mineralization in the loam soil was abolished by heat sterilization. Addition of biosolids to sterile or non-sterile soil did not accelerate the dissipation of diclofenac. These findings indicate that diclofenac is readily biodegradable in agricultural soils. PMID:20952049

  3. Composite Sampling Approaches for Bacillus anthracis Surrogate Extracted from Soil.

    PubMed

    France, Brian; Bell, William; Chang, Emily; Scholten, Trudy

    2015-01-01

    Any release of anthrax spores in the U.S. would require action to decontaminate the site and restore its use and operations as rapidly as possible. The remediation activity would require environmental sampling, both initially to determine the extent of contamination (hazard mapping) and post-decon to determine that the site is free of contamination (clearance sampling). Whether the spore contamination is within a building or outdoors, collecting and analyzing what could be thousands of samples can become the factor that limits the pace of restoring operations. To address this sampling and analysis bottleneck and decrease the time needed to recover from an anthrax contamination event, this study investigates the use of composite sampling. Pooling or compositing of samples is an established technique to reduce the number of analyses required, and its use for anthrax spore sampling has recently been investigated. However, use of composite sampling in an anthrax spore remediation event will require well-documented and accepted methods. In particular, previous composite sampling studies have focused on sampling from hard surfaces; data on soil sampling are required to extend the procedure to outdoor use. Further, we must consider whether combining liquid samples, thus increasing the volume, lowers the sensitivity of detection and produces false negatives. In this study, methods to composite bacterial spore samples from soil are demonstrated. B. subtilis spore suspensions were used as a surrogate for anthrax spores. Two soils (Arizona Test Dust and sterilized potting soil) were contaminated and spore recovery with composites was shown to match individual sample performance. Results show that dilution can be overcome by concentrating bacterial spores using standard filtration methods. This study shows that composite sampling can be a viable method of pooling samples to reduce the number of analysis that must be performed during anthrax spore remediation. PMID:26714315

  4. Composite Sampling Approaches for Bacillus anthracis Surrogate Extracted from Soil.

    PubMed

    France, Brian; Bell, William; Chang, Emily; Scholten, Trudy

    2015-01-01

    Any release of anthrax spores in the U.S. would require action to decontaminate the site and restore its use and operations as rapidly as possible. The remediation activity would require environmental sampling, both initially to determine the extent of contamination (hazard mapping) and post-decon to determine that the site is free of contamination (clearance sampling). Whether the spore contamination is within a building or outdoors, collecting and analyzing what could be thousands of samples can become the factor that limits the pace of restoring operations. To address this sampling and analysis bottleneck and decrease the time needed to recover from an anthrax contamination event, this study investigates the use of composite sampling. Pooling or compositing of samples is an established technique to reduce the number of analyses required, and its use for anthrax spore sampling has recently been investigated. However, use of composite sampling in an anthrax spore remediation event will require well-documented and accepted methods. In particular, previous composite sampling studies have focused on sampling from hard surfaces; data on soil sampling are required to extend the procedure to outdoor use. Further, we must consider whether combining liquid samples, thus increasing the volume, lowers the sensitivity of detection and produces false negatives. In this study, methods to composite bacterial spore samples from soil are demonstrated. B. subtilis spore suspensions were used as a surrogate for anthrax spores. Two soils (Arizona Test Dust and sterilized potting soil) were contaminated and spore recovery with composites was shown to match individual sample performance. Results show that dilution can be overcome by concentrating bacterial spores using standard filtration methods. This study shows that composite sampling can be a viable method of pooling samples to reduce the number of analysis that must be performed during anthrax spore remediation.

  5. Composite Sampling Approaches for Bacillus anthracis Surrogate Extracted from Soil

    PubMed Central

    France, Brian; Bell, William; Chang, Emily; Scholten, Trudy

    2015-01-01

    Any release of anthrax spores in the U.S. would require action to decontaminate the site and restore its use and operations as rapidly as possible. The remediation activity would require environmental sampling, both initially to determine the extent of contamination (hazard mapping) and post-decon to determine that the site is free of contamination (clearance sampling). Whether the spore contamination is within a building or outdoors, collecting and analyzing what could be thousands of samples can become the factor that limits the pace of restoring operations. To address this sampling and analysis bottleneck and decrease the time needed to recover from an anthrax contamination event, this study investigates the use of composite sampling. Pooling or compositing of samples is an established technique to reduce the number of analyses required, and its use for anthrax spore sampling has recently been investigated. However, use of composite sampling in an anthrax spore remediation event will require well-documented and accepted methods. In particular, previous composite sampling studies have focused on sampling from hard surfaces; data on soil sampling are required to extend the procedure to outdoor use. Further, we must consider whether combining liquid samples, thus increasing the volume, lowers the sensitivity of detection and produces false negatives. In this study, methods to composite bacterial spore samples from soil are demonstrated. B. subtilis spore suspensions were used as a surrogate for anthrax spores. Two soils (Arizona Test Dust and sterilized potting soil) were contaminated and spore recovery with composites was shown to match individual sample performance. Results show that dilution can be overcome by concentrating bacterial spores using standard filtration methods. This study shows that composite sampling can be a viable method of pooling samples to reduce the number of analysis that must be performed during anthrax spore remediation. PMID:26714315

  6. Response of Soil Properties and Microbial Communities to Agriculture: Implications for Primary Productivity and Soil Health Indicators

    PubMed Central

    Trivedi, Pankaj; Delgado-Baquerizo, Manuel; Anderson, Ian C.; Singh, Brajesh K.

    2016-01-01

    Agricultural intensification is placing tremendous pressure on the soil’s capacity to maintain its functions leading to large-scale ecosystem degradation and loss of productivity in the long term. Therefore, there is an urgent need to find early indicators of soil health degradation in response to agricultural management. In recent years, major advances in soil meta-genomic and spatial studies on microbial communities and community-level molecular characteristics can now be exploited as ‘biomarker’ indicators of ecosystem processes for monitoring and managing sustainable soil health under global change. However, a continental scale, cross biome approach assessing soil microbial communities and their functional potential to identify the unifying principles governing the susceptibility of soil biodiversity to land conversion is lacking. We conducted a meta-analysis from a dataset generated from 102 peer-reviewed publications as well as unpublished data to explore how properties directly linked to soil nutritional health (total C and N; C:N ratio), primary productivity (NPP) and microbial diversity and composition (relative abundance of major bacterial phyla determined by next generation sequencing techniques) are affected in response to agricultural management across the main biomes of Earth (arid, continental, temperate and tropical). In our analysis, we found strong statistical trends in the relative abundance of several bacterial phyla in agricultural (e.g., Actinobacteria and Chloroflexi) and natural (Acidobacteria, Proteobacteria, and Cyanobacteria) systems across all regions and these trends correlated well with many soil properties. However, main effects of agriculture on soil properties and productivity were biome-dependent. Our meta-analysis provides evidence on the predictable nature of the microbial community responses to vegetation type. This knowledge can be exploited in future for developing a new set of indicators for primary productivity and

  7. Measurement of natural radioactivity in chemical fertilizer and agricultural soil: evidence of high alpha activity.

    PubMed

    Ghosh, Dipak; Deb, Argha; Bera, Sukumar; Sengupta, Rosalima; Patra, Kanchan Kumar

    2008-02-01

    People are exposed to ionizing radiation from the radionuclides that are present in different types of natural sources, of which phosphate fertilizer is one of the most important sources. Radionuclides in phosphate fertilizer belonging to 232Th and 238U series as well as radioisotope of potassium (40K) are the major contributors of outdoor terrestrial natural radiation. The study of alpha activity in fertilizers, which is the first ever in West Bengal, has been performed in order to determine the effect of the use of phosphate fertilizers on human health. The data have been compared with the alpha activity of different types of chemical fertilizers. The measurement of alpha activity in surface soil samples collected from the cultivated land was also performed. The sampling sites were randomly selected in the cultivated land in the Midnapore district, which is the largest district in West Bengal. The phosphate fertilizer is widely used for large agricultural production, mainly potatoes. The alpha activities have been measured using solid-state nuclear track detectors (SSNTD), a very sensitive detector for alpha particles. The results show that alpha activity of those fertilizer and soil samples varies from 141 Bq/kg to 2,589 Bq/kg and from 109 Bq/kg to 660 Bq/kg, respectively. These results were used to estimate environmental radiation exposure on human health contributed by the direct application of fertilizers.

  8. Plant available silicon in South-east Asian rice paddy soils - relevance of agricultural practice and of abiotic factors

    NASA Astrophysics Data System (ADS)

    Marxen, A.; Klotzbücher, T.; Vetterlein, D.; Jahn, R.

    2012-12-01

    Background Silicon (Si) plays a crucial role in rice production. Si content of rice plants exceeds the content of other major nutrients such as nitrogen, phosphorous or potassium. Recent studies showed that in some environments external supply of Si can enhance the growth of rice plants. Rice plants express specific Si transporters to absorb Si from soil solutions in form of silicic acid, which precipitates in tissue cells forming amorphous silica bodies, called phytoliths. The phytoliths are returned to soils with plant residues. They might be a main source of plant available silicic acid in soils. Aims In this study we assess the effects of rice paddy cultivation on the stocks of `reactive` Si fractions in mineral topsoils of rice paddy fields in contrasting landscapes. The `reactive` Si fractions are presumed to determine the release of plant-available silicic acid in soils. We consider the relevance of abiotic factors (mineral assemblage; soil weathering status) and agricultural practice for these fractions. Agricultural practices, which were assumed to affect the stocks of `reactive` Si were (i) the usage of different rice varieties (which might differ in Si demand), (ii) straw residue management (i.e., whether straw residues are returned to the fields or removed and used e.g. as fodder), and (iii) yield level and number of crops per year. Material and methods Soils (top horizon of about 0-20 cm depth) were sampled from rice paddy fields in 2 mountainous and 5 lowland landscapes of contrasting geologic conditions in Vietnam and the Philippines. Ten paddy fields were sampled per landscape. The rice paddy management within landscapes differed when different farmers and/or communities managed the fields. We analysed the following fractions of `reactive` Si in the soils: acetate-extractable Si (dissolved and easily exchangeable Si), phosphate-extractable Si (adsorbed Si), oxalate extractable Si (Si associated with poorly-ordered sesquioxides), NaOH extractable Si

  9. 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

  10. Organoclays as soil amendments to increase the efficacy and reduce the environmental impact of the herbicide fluometuron in agricultural soils.

    PubMed

    Gámiz, Beatriz; Celis, Rafael; Hermosín, María C; Cornejo, Juan

    2010-07-14

    The use of pesticides in agriculture has become a source of pollution of soil and water in the last decades. Extensive pesticide transport losses due to leaching and runoff produce nonpoint source contamination of soils and water. One of the soil processes that reduce pesticide transport losses is adsorption by soil particles; therefore, enhancement of pesticide retention by soil can be used as a strategy to attenuate the environmental impact of pesticides. In this work, organoclays were prepared by treating Wyoming montmorillonite (SWy-2) and Arizona montmorillonite (SAz-1) with different organic cations and were assayed as soil amendments to enhance the retention and reduce the leaching losses of the herbicide fluometuron [N,N-dimethyl-N'-[3-(trifluoromethyl)phenyl] urea] in soils. Two agricultural soils from Southern Spain were selected for being high-risk scenarios of ground and surface water contamination. First, a batch adsorption study was conducted to identify organoclays with high affinity for fluometuron. Among the different organoclays assayed, spermine-treated Wyoming montmorillonite (SW-SPERM) displayed high and reversible adsorption of fluometuron and was selected as an amendment for subsequent persistence, leaching, and herbicidal activity experiments of fluometuron with unamended and amended soils. Amendment of the soils with SW-SPERM at rates of 1%, 2%, and 5% greatly enhanced fluometuron retention by the soils and retarded fluometuron leaching through soil columns. Incubation experiments revealed