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Sample records for addition soil samples

  1. 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 With the inner closed tube withdrawn a selected distance, the outer tube can be inserted into the ground or other similar soft material to withdraw a sample of material for examination.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.

  2. 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 With the inner closed tube withdrawn a selected distance, the outer tube can be inserted into the ground or other similar soft material to withdraw a sample of material for examination.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.

  3. 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.

  4. 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.

  5. 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.

  6. Biochar addition impacts soil microbial community in tropical soils

    NASA Astrophysics Data System (ADS)

    Paz-Ferreiro, Jorge; Fu, Shenglei; Méndez, Ana; Gascó, Gabriel

    2014-05-01

    Studies on the effect of biochar on soil microbial activity and community structure in tropical areas are scarce. In this study we report the effect of several types of biochar (sewage sludge biochar, paper mill waste biochar, miscanthus biochar and pinewood biochar) in the soil microbial community of two tropical soils, an Acrisol and an Oxisol. In addition we study the effect of the presence or absence of earthworms in soil microbial community. Soil microbial community was more strongly affected by biochar than by the presence or absence of macrofauna.

  7. 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

  8. 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...

  9. 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)

  10. 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.

  11. Effects of water addition on soil arthropods and soil characteristics in a precipitation-limited environment

    NASA Astrophysics Data System (ADS)

    Chikoski, Jennifer M.; Ferguson, Steven H.; Meyer, Lense

    2006-09-01

    We investigated the effect of water addition and season on soil arthropod abundance and soil characteristics (%C, %N, C:N, moisture, pH). The experimental design consisted of 24 groups of five boxes distributed within a small aspen stand in Saskatchewan, Canada. The boxes depressed the soil to create a habitat with suitable microclimate for soil arthropods, and by overturning boxes we counted soil arthropods during weekly surveys from April to September 1999. Soil samples were collected at two-month intervals and water was added once per week to half of the plots. Of the eleven recognizable taxonomic units identified, only mites (Acari) and springtails (Collembola) responded to water addition by increasing abundance, whereas ants decreased in abundance with water addition. During summer, springtail numbers increased with water addition, whereas pH was a stronger determinant of mite abundance. In autumn, springtails were positively correlated with water and negatively correlated with mites, whereas mite abundance was negatively correlated with increasing C:N ratio, positively correlated to water addition, and negatively correlated with springtail abundance. Although both mite and springtail numbers decreased in autumn with a decrease in soil moisture, mites became more abundant than springtails suggesting a predator-prey (mite-springtail) relationship. Water had a significant effect on both springtails and mites in summer and autumn supporting the assertion that prairie soil communities are water limited.

  12. Immobilization of uranium in contaminated soil by natural apatite addition

    SciTech Connect

    Mrdakovic Popic, Jelena; Stojanovic, Mirjana; Milosevic, Sinisa; Iles, Deana; Zildzovic, Snezana

    2007-07-01

    Available in abstract form only. Full text of publication follows: The goal of this study was to evaluate the effectiveness of Serbian natural mineral apatite as soil additive for reducing the migration of uranium from contaminated sediments. In laboratory study we investigated the sorption properties of domestic apatite upon different experimental conditions, such as pH, adsorbent mass, reaction period, concentration of P{sub 2}O{sub 5} in apatite, solid/liquid ratio. In second part of study, we did the quantification of uranium in soil samples, taken from uranium mine site 'Kalna', by sequential extraction method. The same procedure was, also, used for uranium determination in contaminated soil samples after apatite addition, in order to determine the changes in U distribution in soil fraction. The obtained results showed the significant level of immobilization (96.7%) upon certain conditions. Increase of %P{sub 2}O{sub 5} in apatite and process of mechano-chemical activation led to increase of immobilization capacity from 17.50% till 91.64%. The best results for uranium binding were obtained at pH 5.5 and reaction period 60 days (98.04%) The sequential extraction showed the presence of uranium (48.2%) in potentially available soil fractions, but with the apatite addition uranium content in these fractions decreased (30.64%), what is considering environmental aspect significant fact. In situ immobilization of radionuclide using inexpensive sequestering agents, such as apatite, is very adequate for big contaminated areas of soil with low level of contamination. This investigation study on natural apatite from deposit 'Lisina' Serbia was the first one of this type in our country. Key words: apatite, uranium, immobilization, soil, contamination. (authors)

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. A global analysis of soil acidification caused by nitrogen addition

    NASA Astrophysics Data System (ADS)

    Tian, Dashuan; Niu, Shuli

    2015-02-01

    Nitrogen (N) deposition-induced soil acidification has become a global problem. However, the response patterns of soil acidification to N addition and the underlying mechanisms remain far from clear. Here, we conducted a meta-analysis of 106 studies to reveal global patterns of soil acidification in responses to N addition. We found that N addition significantly reduced soil pH by 0.26 on average globally. However, the responses of soil pH varied with ecosystem types, N addition rate, N fertilization forms, and experimental durations. Soil pH decreased most in grassland, whereas boreal forest was not observed a decrease to N addition in soil acidification. Soil pH decreased linearly with N addition rates. Addition of urea and NH4NO3 contributed more to soil acidification than NH4-form fertilizer. When experimental duration was longer than 20 years, N addition effects on soil acidification diminished. Environmental factors such as initial soil pH, soil carbon and nitrogen content, precipitation, and temperature all influenced the responses of soil pH. Base cations of Ca2+, Mg2+ and K+ were critical important in buffering against N-induced soil acidification at the early stage. However, N addition has shifted global soils into the Al3+ buffering phase. Overall, this study indicates that acidification in global soils is very sensitive to N deposition, which is greatly modified by biotic and abiotic factors. Global soils are now at a buffering transition from base cations (Ca2+, Mg2+ and K+) to non-base cations (Mn2+ and Al3+). This calls our attention to care about the limitation of base cations and the toxic impact of non-base cations for terrestrial ecosystems with N deposition.

  19. 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.

  20. 7 CFR 27.25 - Additional samples of cotton; drawing.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Additional samples of cotton; drawing. 27.25 Section... CONTAINER REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Inspection and Samples § 27.25 Additional samples of cotton; drawing. In addition to the samples hereinbefore...

  1. 7 CFR 27.25 - Additional samples of cotton; drawing.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Additional samples of cotton; drawing. 27.25 Section... CONTAINER REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Inspection and Samples § 27.25 Additional samples of cotton; drawing. In addition to the samples hereinbefore...

  2. 7 CFR 27.25 - Additional samples of cotton; drawing.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Additional samples of cotton; drawing. 27.25 Section... CONTAINER REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Inspection and Samples § 27.25 Additional samples of cotton; drawing. In addition to the samples hereinbefore...

  3. 7 CFR 27.25 - Additional samples of cotton; drawing.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Additional samples of cotton; drawing. 27.25 Section... CONTAINER REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Inspection and Samples § 27.25 Additional samples of cotton; drawing. In addition to the samples hereinbefore...

  4. 7 CFR 27.25 - Additional samples of cotton; drawing.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Additional samples of cotton; drawing. 27.25 Section... CONTAINER REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Inspection and Samples § 27.25 Additional samples of cotton; drawing. In addition to the samples hereinbefore...

  5. Regulation of Soil Microbial Carbon-use Efficiency by Soil Moisture, Substrate Addition, and Incubation Time

    NASA Astrophysics Data System (ADS)

    Stark, J.

    2015-12-01

    Microbial carbon-use efficiency (CUE) is a key variable in biogeochemical cycling that regulates soil C sequestration, greenhouse gas emissions, and retention of inorganic nutrients. Microbial CUE is the fraction of C converted to biomass rather than respired as CO2. Biogeochemical models have been shown to be highly sensitive to variation in CUE; however, we currently have a poor understanding of how CUE responds to environmental variables such as soil moisture and nutrient limitations. We examined the effect of soil moisture and C supply on CUE in soil from a western hemlock / sitka spruce forest in Oregon, USA, using a novel technique which supplies 13C and 15N substrates through the gas phase so that water addition is not necessary. Soil samples (28 g oven-dry equiv. wt) at two water potentials (-0.03 and -3.55 MPa) were exposed to 13C-acetic acid vapor for either 6 or 30 sec to provide two different concentrations of acetate to soil microbial communities. The soils were also injected with small amounts of 15NH3 gas to allow quantification of microbial N assimilation rates and to provide an alternate method of calculating CUE. Rates of 13CO2 respiration were measured continuously during a 48-h incubation using cavity ring-down spectroscopy. Soil samples were extracted at seven time intervals (0, 0.5, 1.5, 4.5, 12, 24, and 48 h) in 0.5 M K2SO4 and analyzed for DO13C, microbial 13C, DO15N, inorganic 15N, and microbial 15N to calculate how gross rates of C and N assimilation and microbial CUE change with incubation time. As expected, microbial C and N assimilation rates and CUE increased with soil moisture and the quantity of acetate added; however, C:N assimilated was higher at lower soil moisture, suggesting that either C-storage compounds were being created, or that fungal communities were responsible for a greater proportion of the assimilation in drier soils. Assimilation rates and CUE also changed with incubation time, demonstrating that estimates of CUE

  6. 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.

  7. 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.

  8. 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.

  9. Predicting the impact of biochar additions on soil hydraulic properties.

    PubMed

    Lim, T J; Spokas, K A; Feyereisen, G; Novak, J M

    2016-01-01

    Different physical and chemical properties of biochar, which is made out of a variety of biomass materials, can impact water movement through amended soil. The objective of this research was to develop a decision support tool predicting the impact of biochar additions on soil saturated hydraulic conductivity (Ksat). Four different kinds of biochar were added to four different textured soils (coarse sand, fine sand, loam, and clay texture) to assess these effects at the rates of 0%, 1%, 2%, and 5% (w/w). The Ksat of the biochar amended soils were significantly influenced by the rate and type of biochar, as well as the original particle size of soil. The Ksat decreased when biochar was added to coarse and fine sands. Biochar with larger particles sizes (60%; >1 mm) decreased Ksat to a larger degree than the smaller particle size biochar (60%; <1 mm) in the two sandy textured soils. Increasing tortuosity in the biochar amended sandy soil could explain this behavior. On the other hand, for the clay loam 1% and 2% biochar additions universally increased the Ksat with higher biochar amounts providing no further alterations. The developed model utilizes soil texture pedotransfer functions for predicting agricultural soil Ksat as a function of soil texture. The model accurately predicted the direction of the Ksat influence, even though the exact magnitude still requires further refinement. This represents the first step to a unified theory behind the impact of biochar additions on soil saturated conductivity. PMID:26145507

  10. Predicting the impact of biochar additions on soil hydraulic properties.

    PubMed

    Lim, T J; Spokas, K A; Feyereisen, G; Novak, J M

    2016-01-01

    Different physical and chemical properties of biochar, which is made out of a variety of biomass materials, can impact water movement through amended soil. The objective of this research was to develop a decision support tool predicting the impact of biochar additions on soil saturated hydraulic conductivity (Ksat). Four different kinds of biochar were added to four different textured soils (coarse sand, fine sand, loam, and clay texture) to assess these effects at the rates of 0%, 1%, 2%, and 5% (w/w). The Ksat of the biochar amended soils were significantly influenced by the rate and type of biochar, as well as the original particle size of soil. The Ksat decreased when biochar was added to coarse and fine sands. Biochar with larger particles sizes (60%; >1 mm) decreased Ksat to a larger degree than the smaller particle size biochar (60%; <1 mm) in the two sandy textured soils. Increasing tortuosity in the biochar amended sandy soil could explain this behavior. On the other hand, for the clay loam 1% and 2% biochar additions universally increased the Ksat with higher biochar amounts providing no further alterations. The developed model utilizes soil texture pedotransfer functions for predicting agricultural soil Ksat as a function of soil texture. The model accurately predicted the direction of the Ksat influence, even though the exact magnitude still requires further refinement. This represents the first step to a unified theory behind the impact of biochar additions on soil saturated conductivity.

  11. 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...

  12. 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.

  13. Effect of Exogenous Phytase Addition on Soil Phosphatase Activities: a Fluorescence Spectroscopy Study.

    PubMed

    Yang, Xiao-zhu; Chen, Zhen-hua; Zhang, Yu-lan; Chen, Li-jun

    2015-05-01

    The utilization of organic phosphorus (P) has directly or indirectly improved after exogenous phytase was added to soil. However, the mechanism by which exogenous phytase affected the soil phosphatases (phosphomonoesterase and phosphodiesterase) activities was not clear. The present work was aimed to study red soil, brown soil and cinnamon soil phosphomonoesterase (acid and alkaline) (AcP and AlP) and phosphodiesterase (PD) activities responding to the addition of exogenous phytase (1 g phytase/50 g air dry soil sample) based on the measurements performed via a fluorescence detection method combined with 96 microplates using a TECAN Infinite 200 Multi-Mode Microplate Reader. The results indicated that the acid phosphomonoesterase activity was significantly enhanced in red soil (p≤0. 01), while it was significantly reduced in cinnamon soil; alkaline phosphomonoesterase activity was significantly enhanced in cinnamon soil (p≤ 0. 01), while it was significantly reduced in red soil; phosphodiesterase activity was increased in three soils but it was significantly increased in brown soil (p≤0. 01) after the addition of exogenous phytase. The activities still remained strong after eight days in different soils, which indicated that exogenous phytase addition could be enhance soil phosphatases activities effectively. This effect was not only related to soil properties, such as pH and phosphorus forms, but might also be related to the excreted enzyme amount of the stimulating microorganism. Using fluorescence spectroscopy to study exogenous phytase addition influence on soil phosphatase activities was the first time at home and abroad. Compared with the conventional spectrophotometric method, the fluorescence microplate method is an accurate, fast and simple to use method to determine the relationships among the soil phosphatases activities.

  14. Predicting the impact of biochar additions on soil hydraulic properties

    NASA Astrophysics Data System (ADS)

    Spokas, Kurt; Lim, Tae Jun; Feyereisen, Gary; Novak, Jeff

    2015-04-01

    Different physical and chemical properties of biochar, which is made out of a variety of biomass materials, can impact water movement through amended soil. The objective of this research was to develop a decision support tool predicting the impact of biochar additions on soil saturated hydraulic conductivity (Ksat). Four different kinds of biochar were added to four different textured soils (coarse sand, fine sand, loam, and clay texture) to assess these effects at the rates of 0, 1, 2, and 5 % (w/w). The Ksat of the biochar amended soils were significantly influenced by the rate and type of biochar, as well as the original particle size of soil. The Ksat decreased when biochar was added to coarse and fine sands. Biochar with larger particles sizes (60%; >1 mm) decreased Ksat to a larger degree than the smaller particle size biochar (60%; <1 mm) in the two sandy textured soils. Increasing tortuosity in the amended sandy soil could explain this behavior. On the other hand, for the clay loam 1% and 2% biochar additions universally increased the Ksat with higher biochar amounts providing no further alterations. The developed model utilizes soil texture pedotransfer functions for predicting agricultural soil Ksat as a function of soil texture. The model accurately predicted the direction of the Ksat influence, even though the exact magnitude still requires further refinement.

  15. 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.

  16. 21 CFR 71.4 - Samples; additional information.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... samples of the color additive, articles used as components thereof, or of the food, drug, or cosmetic in... additive, or articles used as components thereof, or of the food, drug, or cosmetic in which the color... respect to the safety of the color additive or the physical or technical effect it produces. The date...

  17. 21 CFR 71.4 - Samples; additional information.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... samples of the color additive, articles used as components thereof, or of the food, drug, or cosmetic in... additive, or articles used as components thereof, or of the food, drug, or cosmetic in which the color... respect to the safety of the color additive or the physical or technical effect it produces. The date...

  18. Optimization of soil mixing technology through metallic iron addition.

    SciTech Connect

    Moos, L. P.

    1999-01-15

    Enhanced soil mixing is a process used to remove volatile organic compounds (VOCs) from soil. In this process, also known as soil mixing with thermally enhanced soil vapor extraction, or SM/TESVE, a soil mixing apparatus breaks up and mixes a column of soil up to 9 m (30 ft) deep; simultaneously, hot air is blown through the soil. The hot air carries the VOCs to the surface where they are collected and safely disposed of. This technology is cost effective at high VOC concentrations, but it becomes cost prohibitive at low concentrations. Argonne National Laboratory-East conducted a project to evaluate ways of improving the effectiveness of this system. The project investigated the feasibility of integrating the SM/TESVE process with three soil treatment processes--soil vapor extraction, augmented indigenous biodegradation, and zero-valent iron addition. Each of these technologies was considered a polishing treatment designed to remove the contaminants left behind by enhanced soil mixing. The experiment was designed to determine if the overall VOC removal effectiveness and cost-effectiveness of the SM/TESVE process could be improved by integrating this approach with one of the polishing treatment systems.

  19. 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

  20. Residual soil DNA extraction increases the discriminatory power between samples.

    PubMed

    Young, Jennifer M; Weyrich, Laura S; Clarke, Laurence J; Cooper, Alan

    2015-06-01

    Forensic soil analysis relies on capturing an accurate and reproducible representation of the diversity from limited quantities of soil; however, inefficient DNA extraction can markedly alter the taxonomic abundance. The performance of a standard commercial DNA extraction kit (MOBIO PowerSoil DNA Isolation kit) and three modified protocols of this kit: soil pellet re-extraction (RE); an additional 24-h lysis incubation step at room temperature (RT); and 24-h lysis incubation step at 55°C (55) were compared using high-throughput sequencing of the internal transcribed spacer I ribosomal DNA. DNA yield was not correlated with fungal diversity and the four DNA extraction methods displayed distinct fungal community profiles for individual samples, with some phyla detected exclusively using the modified methods. Application of a 24 h lysis step will provide a more complete inventory of fungal biodiversity, and re-extraction of the residual soil pellet offers a novel tool for increasing discriminatory power between forensic soil samples.

  1. Rapid Determination Of Radiostrontium In Large Soil Samples

    SciTech Connect

    Maxwell, Sherrod L.; Culligan, Brian K.; Shaw, Patrick J.

    2012-05-24

    A new method for the determination of radiostrontium in large soil samples has been developed at the Savannah River Environmental Laboratory (Aiken, SC, USA) that allows rapid preconcentration and separation of strontium in large soil samples for the measurement of strontium isotopes by gas flow proportional counting. The need for rapid analyses in the event of a Radiological Dispersive Device (RDD) or Improvised Nuclear Device (IND) event is well-known. In addition, the recent accident at Fukushima Nuclear Power Plant in March, 2011 reinforces the need to have rapid analyses for radionuclides in environmental samples in the event of a nuclear accident. The method employs a novel pre-concentration step that utilizes an iron hydroxide precipitation (enhanced with calcium phosphate) followed by a final calcium fluoride precipitation to remove silicates and other matrix components. The pre-concentration steps, in combination with a rapid Sr Resin separation using vacuum box technology, allow very large soil samples to be analyzed for {sup 89,90}Sr using gas flow proportional counting with a lower method detection limit. The calcium fluoride precipitation eliminates column flow problems typically associated with large amounts of silicates in large soil samples.

  2. 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.

  3. 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

  4. Applicability and limitations of enzyme addition assays for the characterisation of soil organic phosphorus across a range of soil types

    NASA Astrophysics Data System (ADS)

    Jarosch, Klaus; Doolette, Ashlea; Smernik, Ronald; Frossard, Emmanuel; Bünemann, Else K.

    2014-05-01

    Solution 31P NMR spectroscopy is a powerful tool for the characterisation and quantification of organic P classes in soil. Potential limitations are due to costs, equipment accessibility and the requirement of relatively large amounts of sample. A recent alternative approach for the quantification of specific organic P classes is the use of substrate-specific phosphohydrolase enzymes which cleave the inorganic orthophosphate from the organic moiety. The released orthophosphate is detectable by colorimetry. Conclusions about the hydrolysed class of organic P can be made based on the comparison of inorganic P concentrations in enzymatically treated and untreated samples. The aim of this study was to test the applicability of enzyme addition assays for the characterisation of organic P classes on a) NaOH-EDTA extracts, b) soil:water filtrates (0.2 μm) and c) soil:water suspensions. The organic P classes in NaOH-EDTA extracts were also determined by 31P NMR spectroscopy, enabling a comparison between methods. Ten topsoil samples from four continents (five cambisols, two ferralsols, two luvisols and one lixisol) with varying total P content (83 - 1,1560 mg kg-1), pHH2O (4.2 - 8.0) and land management (grassland or cropped land) were analysed. Four different classes of organic P were determined by the enzyme addition assay: 1) monoester like-P (by an acid phosphatase known to hydrolyse simple monoesters, pyrophosphate and ATP), 2) DNA-like P (by a nuclease in combination with an acid phosphatase), 3) inositol phosphate-like P (by a phytase known to hydrolyse all monoester like-P plus myo-inositol hexakisphosphate and scyllo-inositol hexakisphosphate) and 4) enzyme stable-P (enzymatically not hydrolysed organic P forms). In the ten topsoil samples, NaOH-EDTA-extractable organic P ranged from 6 - 1,115 mg P kg-1 soil. Of this, 33 - 92 % was enzyme labile, with inositol phosphate-like P being the largest organic P class in most soils (15 - 51%), followed by monoester

  5. Effect of N and P addition on soil organic C potential mineralization in forest soils in South China.

    PubMed

    Ouyang, Xuejun; Zhou, Guoyi; Huang, Zhongliang; Zhou, Cunyu; Li, Jiong; Shi, Junhui; Zhang, Deqiang

    2008-01-01

    Atmospheric nitrogen deposition is at a high level in some forests of South China. The effects of addition of exogenous N and P on soil organic carbon mineralization were studied to address: (1) if the atmospheric N deposition promotes soil C storage through decreasing mineralization; (2) if the soil available P is a limitation to organic carbon mineralization. Soils (0-10 cm) was sampled from monsoon evergreen broad-leaved forest (MEBF), coniferous and broad-leaved mixed forest (CBMF), and Pinus massoniana forest (PMF) in Dinghushan Biosphere Reserve (located in Guangdong Province, China). The soils were incubated at 25 degrees C for 45 weeks, with addition of N (NH4NO3 solution) or P (KH2PO4 solution). CO2-C emission and the inorganic N (NH4(+)-N and NO3(-)-N) of the soils were determined during the incubation. The results showed that CO2-C emission decreased with the N addition. The addition of P led to a short-term sharp increase in CO2 emission after P application, and the responses of CO2-C evolution to P addition in the later period of incubation related to forest types. Strong P inhibition to CO2 emission occurred in both PMF and CBMF soils in the later incubation. The two-pool kinetic model was fitted well to the data for C turnover in this experiment. The model analysis demonstrated that the addition of N and P changed the distribution of soil organic C between the labile and recalcitrant pool, as well as their mineralization rates. In our experiment, soil pH can not completely explain the negative effect of N addition on CO2-C emission. The changes of soil inorganic N during incubation seemed to support the hypothesis that the polymerization of added nitrogen with soil organic compound by abiotic reactions during incubation made the added nitrogen retard the soil organic carbon mineralization. We conclude that atmospheric N deposition contributes to soil C accretion in the three subtropical forest ecosystems, however, the shortage of soil available P in

  6. Influence of attrition scrubbing, ultrasonic treatment, and oxidant additions on uranium removal from contaminated soils

    SciTech Connect

    Timpson, M.E.; Elless, M.P.; Francis, C.W.

    1994-06-01

    As part of the Uranium in Soils Integrated Demonstration Project being conducted by the US Department of Energy, bench-scale investigations of selective leaching of uranium from soils at the Fernald Environmental Management Project site in Ohio were conducted at Oak Ridge National Laboratory. Two soils (storage pad soil and incinerator soil), representing the major contaminant sources at the site, were extracted using carbonate- and citric acid-based lixiviants. Physical and chemical processes were used in combination with the two extractants to increase the rate of uranium release from these soils. Attrition scrubbing and ultrasonic dispersion were the two physical processes utilized. Potassium permanganate was used as an oxidizing agent to transform tetravalent uranium to the hexavalent state. Hexavalent uranium is easily complexed in solution by the carbonate radical. Attrition scrubbing increased the rate of uranium release from both soils when compared with rotary shaking. At equivalent extraction times and solids loadings, however, attrition scrubbing proved effective only on the incinerator soil. Ultrasonic treatments on the incinerator soil removed 71% of the uranium contamination in a single extraction. Multiple extractions of the same sample removed up to 90% of the uranium. Additions of potassium permanganate to the carbonate extractant resulted in significant changes in the extractability of uranium from the incinerator soil but had no effect on the storage pad soil.

  7. Soil bacterial and fungal community responses to nitrogen addition across soil depth and microhabitat in an arid shrubland

    SciTech Connect

    Mueller, Rebecca C.; Belnap, Jayne; Kuske, Cheryl R.

    2015-09-04

    Arid shrublands are stressful environments, typified by alkaline soils low in organic matter, with biologically-limiting extremes in water availability, temperature, and UV radiation. The widely-spaced plants and interspace biological soil crusts in these regions provide soil nutrients in a localized fashion, creating a mosaic pattern of plant- or crust-associated microhabitats with distinct nutrient composition. With sporadic and limited rainfall, nutrients are primarily retained in the shallow surface soil, patterning biological activity. We examined soil bacterial and fungal community responses to simulated nitrogen (N) deposition in an arid Larrea tridentata-Ambrosia dumosa field experiment in southern Nevada, USA, using high-throughput sequencing of ribosomal RNA genes. To examine potential interactions among the N application, microhabitat and soil depth, we sampled soils associated with shrub canopies and interspace biological crusts at two soil depths (0–0.5 or 0–10 cm) across the N-amendment gradient (0, 7, and 15 kg ha–1 yr–1). We hypothesized that localized compositional differences in soil microbiota would constrain the impacts of N addition to a microhabitat distribution that would reflect highly localized geochemical conditions and microbial community composition. The richness and community composition of both bacterial and fungal communities differed significantly by microhabitat and with soil depth in each microhabitat. Only bacterial communities exhibited significant responses to the N addition. Community composition correlated with microhabitat and depth differences in soil geochemical features. Provided the distinct roles of soil bacteria and fungi in major nutrient cycles, the resilience of fungi and sensitivity of bacteria to N amendments suggests that increased N input predicted for many arid ecosystems could shift nutrient cycling toward pathways driven primarily by fungal communities.

  8. Soil bacterial and fungal community responses to nitrogen addition across soil depth and microhabitat in an arid shrubland

    DOE PAGES

    Mueller, Rebecca C.; Belnap, Jayne; Kuske, Cheryl R.

    2015-09-04

    Arid shrublands are stressful environments, typified by alkaline soils low in organic matter, with biologically-limiting extremes in water availability, temperature, and UV radiation. The widely-spaced plants and interspace biological soil crusts in these regions provide soil nutrients in a localized fashion, creating a mosaic pattern of plant- or crust-associated microhabitats with distinct nutrient composition. With sporadic and limited rainfall, nutrients are primarily retained in the shallow surface soil, patterning biological activity. We examined soil bacterial and fungal community responses to simulated nitrogen (N) deposition in an arid Larrea tridentata-Ambrosia dumosa field experiment in southern Nevada, USA, using high-throughput sequencing ofmore » ribosomal RNA genes. To examine potential interactions among the N application, microhabitat and soil depth, we sampled soils associated with shrub canopies and interspace biological crusts at two soil depths (0–0.5 or 0–10 cm) across the N-amendment gradient (0, 7, and 15 kg ha–1 yr–1). We hypothesized that localized compositional differences in soil microbiota would constrain the impacts of N addition to a microhabitat distribution that would reflect highly localized geochemical conditions and microbial community composition. The richness and community composition of both bacterial and fungal communities differed significantly by microhabitat and with soil depth in each microhabitat. Only bacterial communities exhibited significant responses to the N addition. Community composition correlated with microhabitat and depth differences in soil geochemical features. Provided the distinct roles of soil bacteria and fungi in major nutrient cycles, the resilience of fungi and sensitivity of bacteria to N amendments suggests that increased N input predicted for many arid ecosystems could shift nutrient cycling toward pathways driven primarily by fungal communities.« less

  9. Soil bacterial and fungal community responses to nitrogen addition across soil depth and microhabitat in an arid shrubland

    USGS Publications Warehouse

    Mueller, Rebecca C; Belnap, Jayne; Kuske, Cheryl R

    2015-01-01

    Arid shrublands are stressful environments, typified by alkaline soils low in organic matter, with biologically-limiting extremes in water availability, temperature, and UV radiation. The widely-spaced plants and interspace biological soil crusts in these regions provide soil nutrients in a localized fashion, creating a mosaic pattern of plant- or crust-associated microhabitats with distinct nutrient composition. With sporadic and limited rainfall, nutrients are primarily retained in the shallow surface soil, patterning biological activity. We examined soil bacterial and fungal community responses to simulated nitrogen (N) deposition in an arid Larrea tridentata-Ambrosia dumosa field experiment in southern Nevada, USA, using high-throughput sequencing of ribosomal RNA genes. To examine potential interactions among the N application, microhabitat and soil depth, we sampled soils associated with shrub canopies and interspace biological crusts at two soil depths (0–0.5 or 0–10 cm) across the N-amendment gradient (0, 7, and 15 kg ha−1 yr−1). We hypothesized that localized compositional differences in soil microbiota would constrain the impacts of N addition to a microhabitat distribution that would reflect highly localized geochemical conditions and microbial community composition. The richness and community composition of both bacterial and fungal communities differed significantly by microhabitat and with soil depth in each microhabitat. Only bacterial communities exhibited significant responses to the N addition. Community composition correlated with microhabitat and depth differences in soil geochemical features. Given the distinct roles of soil bacteria and fungi in major nutrient cycles, the resilience of fungi and sensitivity of bacteria to N amendments suggests that increased N input predicted for many arid ecosystems could shift nutrient cycling toward pathways driven primarily by fungal communities.

  10. Soil bacterial and fungal community responses to nitrogen addition across soil depth and microhabitat in an arid shrubland

    PubMed Central

    Mueller, Rebecca C.; Belnap, Jayne; Kuske, Cheryl R.

    2015-01-01

    Arid shrublands are stressful environments, typified by alkaline soils low in organic matter, with biologically-limiting extremes in water availability, temperature, and UV radiation. The widely-spaced plants and interspace biological soil crusts in these regions provide soil nutrients in a localized fashion, creating a mosaic pattern of plant- or crust-associated microhabitats with distinct nutrient composition. With sporadic and limited rainfall, nutrients are primarily retained in the shallow surface soil, patterning biological activity. We examined soil bacterial and fungal community responses to simulated nitrogen (N) deposition in an arid Larrea tridentata-Ambrosia dumosa field experiment in southern Nevada, USA, using high-throughput sequencing of ribosomal RNA genes. To examine potential interactions among the N application, microhabitat and soil depth, we sampled soils associated with shrub canopies and interspace biological crusts at two soil depths (0–0.5 or 0–10 cm) across the N-amendment gradient (0, 7, and 15 kg ha−1 yr−1). We hypothesized that localized compositional differences in soil microbiota would constrain the impacts of N addition to a microhabitat distribution that would reflect highly localized geochemical conditions and microbial community composition. The richness and community composition of both bacterial and fungal communities differed significantly by microhabitat and with soil depth in each microhabitat. Only bacterial communities exhibited significant responses to the N addition. Community composition correlated with microhabitat and depth differences in soil geochemical features. Given the distinct roles of soil bacteria and fungi in major nutrient cycles, the resilience of fungi and sensitivity of bacteria to N amendments suggests that increased N input predicted for many arid ecosystems could shift nutrient cycling toward pathways driven primarily by fungal communities. PMID:26388845

  11. Soil bacterial and fungal community responses to nitrogen addition across soil depth and microhabitat in an arid shrubland.

    PubMed

    Mueller, Rebecca C; Belnap, Jayne; Kuske, Cheryl R

    2015-01-01

    Arid shrublands are stressful environments, typified by alkaline soils low in organic matter, with biologically-limiting extremes in water availability, temperature, and UV radiation. The widely-spaced plants and interspace biological soil crusts in these regions provide soil nutrients in a localized fashion, creating a mosaic pattern of plant- or crust-associated microhabitats with distinct nutrient composition. With sporadic and limited rainfall, nutrients are primarily retained in the shallow surface soil, patterning biological activity. We examined soil bacterial and fungal community responses to simulated nitrogen (N) deposition in an arid Larrea tridentata-Ambrosia dumosa field experiment in southern Nevada, USA, using high-throughput sequencing of ribosomal RNA genes. To examine potential interactions among the N application, microhabitat and soil depth, we sampled soils associated with shrub canopies and interspace biological crusts at two soil depths (0-0.5 or 0-10 cm) across the N-amendment gradient (0, 7, and 15 kg ha(-1) yr(-1)). We hypothesized that localized compositional differences in soil microbiota would constrain the impacts of N addition to a microhabitat distribution that would reflect highly localized geochemical conditions and microbial community composition. The richness and community composition of both bacterial and fungal communities differed significantly by microhabitat and with soil depth in each microhabitat. Only bacterial communities exhibited significant responses to the N addition. Community composition correlated with microhabitat and depth differences in soil geochemical features. Given the distinct roles of soil bacteria and fungi in major nutrient cycles, the resilience of fungi and sensitivity of bacteria to N amendments suggests that increased N input predicted for many arid ecosystems could shift nutrient cycling toward pathways driven primarily by fungal communities. PMID:26388845

  12. Use of Additives in Bioremediation of Contaminated Groundwater and Soil

    EPA Science Inventory

    This chapter reviews application of additives used in bioremediation of chlorinated solvents and fuels for groundwater and soil remediation. Soluble carbon substrates are applicable to most site conditions except aquifers with very high or very low groundwater flow. Slow-release ...

  13. Nitrogen addition regulates soil nematode community composition through ammonium suppression.

    PubMed

    Wei, Cunzheng; Zheng, Huifen; Li, Qi; Lü, Xiaotao; Yu, Qiang; Zhang, Haiyang; Chen, Quansheng; He, Nianpeng; Kardol, Paul; Liang, Wenju; Han, Xingguo

    2012-01-01

    Nitrogen (N) enrichment resulting from anthropogenic activities has greatly changed the composition and functioning of soil communities. Nematodes are one of the most abundant and diverse groups of soil organisms, and they occupy key trophic positions in the soil detritus food web. Nematodes have therefore been proposed as useful indicators for shifts in soil ecosystem functioning under N enrichment. Here, we monitored temporal dynamics of the soil nematode community using a multi-level N addition experiment in an Inner Mongolia grassland. Measurements were made three years after the start of the experiment. We used structural equation modeling (SEM) to explore the mechanisms regulating nematode responses to N enrichment. Across the N enrichment gradient, significant reductions in total nematode abundance, diversity (H' and taxonomic richness), maturity index (MI), and the abundance of root herbivores, fungivores and omnivores-predators were found in August. Root herbivores recovered in September, contributing to the temporal variation of total nematode abundance across the N gradient. Bacterivores showed a hump-shaped relationship with N addition rate, both in August and September. Ammonium concentration was negatively correlated with the abundance of total and herbivorous nematodes in August, but not in September. Ammonium suppression explained 61% of the variation in nematode richness and 43% of the variation in nematode trophic group composition. Ammonium toxicity may occur when herbivorous nematodes feed on root fluid, providing a possible explanation for the negative relationship between herbivorous nematodes and ammonium concentration in August. We found a significantly positive relationship between fungivores and fungal phospholipid fatty acids (PLFA), suggesting bottom-up control of fungivores. No such relationship was found between bacterivorous nematodes and bacterial PLFA. Our findings contribute to the understanding of effects of N enrichment in

  14. Microbial Community Responses to Glycine Addition in Kansas Prairie Soils

    NASA Astrophysics Data System (ADS)

    Bottos, E.; Roy Chowdhury, T.; White, R. A., III; Brislawn, C.; Fansler, S.; Kim, Y. M.; Metz, T. O.; McCue, L. A.; Jansson, J.

    2015-12-01

    Advances in sequencing technologies are rapidly expanding our abilities to unravel aspects of microbial community structure and function in complex systems like soil; however, characterizing the highly diverse communities is problematic, due primarily to challenges in data analysis. To tackle this problem, we aimed to constrain the microbial diversity in a soil by enriching for particular functional groups within a community through addition of "trigger substrates". Such trigger substrates, characterized by low molecular weight, readily soluble and diffusible in soil solution, representative of soil organic matter derivatives, would also be rapidly degradable. A relatively small energy investment to maintain the cell in a state of metabolic alertness for such substrates would be a better evolutionary strategy and presumably select for a cohort of microorganisms with the energetics and cellular machinery for utilization and growth. We chose glycine, a free amino acid (AA) known to have short turnover times (in the range of hours) in soil. As such, AAs are a good source of nitrogen and easily degradable, and can serve as building blocks for microbial proteins and other biomass components. We hypothesized that the addition of glycine as a trigger substrate will decrease microbial diversity and evenness, as taxa capable of metabolizing it are enriched in relation to those that are not. We tested this hypothesis by incubating three Kansas native prairie soils with glycine for 24 hours at 21 degree Celsius, and measured community level responses by 16S rRNA gene sequencing, metagenomics, and metatranscriptomics. Preliminary evaluation of 16S rRNA gene sequences revealed minor changes in bacterial community composition in response to glycine addition. We will also present data on functional gene abundance and expression. The results of these analyses will be useful in designing sequencing strategies aimed at dissecting and deciphering complex microbial communities.

  15. Soil microbial responses to nitrogen addition in arid ecosystems

    SciTech Connect

    Sinsabaugh, Robert L.; Belnap, Jayne; Rudgers, Jennifer; Kuske, Cheryl R.; Martinez, Noelle; Sandquist, Darren

    2015-08-14

    The N cycle of arid ecosystems is influenced by low soil organic matter, high soil pH, and extremes in water potential and temperature that lead to open canopies and development of biological soil crusts (biocrusts). We investigated the effects of N amendment on soil microbial dynamics in a Larrea tridentata-Ambrosia dumosa shrubland site in southern Nevada USA. Sites were fertilized with a NO3-NH4 mix at 0, 7, and 15 kg N ha-1 y-1 from March 2012 to March 2013. In March 2013, biocrust (0–0.5 cm) and bulk soils (0–10 cm) were collected beneath Ambrosia canopies and in the interspaces between plants. Biomass responses were assessed as bacterial and fungal SSU rRNA gene copy number and chlorophyll a concentration. Metabolic responses were measured by five ecoenzyme activities and rates of N transformation. With most measures, nutrient availability, microbial biomass, and process rates were greater in soils beneath the shrub canopy compared to the interspace between plants, and greater in the surface biocrust horizon compared to the deeper 10 cm soil profile. Most measures responded positively to experimental N addition. Effect sizes were generally greater for bulk soil than biocrust. Results were incorporated into a meta-analysis of arid ecosystem responses to N amendment that included data from 14 other studies. Effect sizes were calculated for biomass and metabolic responses. Regressions of effect sizes, calculated for biomass, and metabolic responses, showed similar trends in relation to N application rate and N load (rate × duration). The critical points separating positive from negative treatment effects were 88 kg ha-1 y-1 and 159 kg ha-1, respectively, for biomass, and 70 kg ha-1 y-1 and 114 kg ha-1, respectively, for metabolism. These critical values are comparable to those for microbial biomass, decomposition rates and respiration

  16. Soil microbial responses to nitrogen addition in arid ecosystems

    DOE PAGES

    Sinsabaugh, Robert L.; Belnap, Jayne; Rudgers, Jennifer; Kuske, Cheryl R.; Martinez, Noelle; Sandquist, Darren

    2015-08-14

    The N cycle of arid ecosystems is influenced by low soil organic matter, high soil pH, and extremes in water potential and temperature that lead to open canopies and development of biological soil crusts (biocrusts). We investigated the effects of N amendment on soil microbial dynamics in a Larrea tridentata-Ambrosia dumosa shrubland site in southern Nevada USA. Sites were fertilized with a NO3-NH4 mix at 0, 7, and 15 kg N ha-1 y-1 from March 2012 to March 2013. In March 2013, biocrust (0–0.5 cm) and bulk soils (0–10 cm) were collected beneath Ambrosia canopies and in the interspaces betweenmore » plants. Biomass responses were assessed as bacterial and fungal SSU rRNA gene copy number and chlorophyll a concentration. Metabolic responses were measured by five ecoenzyme activities and rates of N transformation. With most measures, nutrient availability, microbial biomass, and process rates were greater in soils beneath the shrub canopy compared to the interspace between plants, and greater in the surface biocrust horizon compared to the deeper 10 cm soil profile. Most measures responded positively to experimental N addition. Effect sizes were generally greater for bulk soil than biocrust. Results were incorporated into a meta-analysis of arid ecosystem responses to N amendment that included data from 14 other studies. Effect sizes were calculated for biomass and metabolic responses. Regressions of effect sizes, calculated for biomass, and metabolic responses, showed similar trends in relation to N application rate and N load (rate × duration). The critical points separating positive from negative treatment effects were 88 kg ha-1 y-1 and 159 kg ha-1, respectively, for biomass, and 70 kg ha-1 y-1 and 114 kg ha-1, respectively, for metabolism. These critical values are comparable to those for microbial biomass, decomposition rates and respiration reported in broader meta-analyses of N amendment effects in mesic ecosystems. The large effect sizes at low N

  17. Soil microbial responses to nitrogen addition in arid ecosystems.

    PubMed

    Sinsabaugh, Robert L; Belnap, Jayne; Rudgers, Jennifer; Kuske, Cheryl R; Martinez, Noelle; Sandquist, Darren

    2015-01-01

    The N cycle of arid ecosystems is influenced by low soil organic matter, high soil pH, and extremes in water potential and temperature that lead to open canopies and development of biological soil crusts (biocrusts). We investigated the effects of N amendment on soil microbial dynamics in a Larrea tridentata-Ambrosia dumosa shrubland site in southern Nevada USA. Sites were fertilized with a NO3-NH4 mix at 0, 7, and 15 kg N ha(-1) y(-1) from March 2012 to March 2013. In March 2013, biocrust (0-0.5 cm) and bulk soils (0-10 cm) were collected beneath Ambrosia canopies and in the interspaces between plants. Biomass responses were assessed as bacterial and fungal SSU rRNA gene copy number and chlorophyll a concentration. Metabolic responses were measured by five ecoenzyme activities and rates of N transformation. By most measures, nutrient availability, microbial biomass, and process rates were greater in soils beneath the shrub canopy compared to the interspace between plants, and greater in the surface biocrust horizon compared to the deeper 10 cm soil profile. Most measures responded positively to experimental N addition. Effect sizes were generally greater for bulk soil than biocrust. Results were incorporated into a meta-analysis of arid ecosystem responses to N amendment that included data from 14 other studies. Effect sizes were calculated for biomass and metabolic responses. Regressions of effect sizes, calculated for biomass, and metabolic responses, showed similar trends in relation to N application rate and N load (rate × duration). The critical points separating positive from negative treatment effects were 88 kg ha(-1) y(-1) and 159 kg ha(-1), respectively, for biomass, and 70 kg ha(-1) y(-1) and 114 kg ha(-1), respectively, for metabolism. These critical values are comparable to those for microbial biomass, decomposition rates and respiration reported in broader meta-analyses of N amendment effects in mesic ecosystems. However, large effect sizes at low N

  18. Soil microbial responses to nitrogen addition in arid ecosystems

    PubMed Central

    Sinsabaugh, Robert L.; Belnap, Jayne; Rudgers, Jennifer; Kuske, Cheryl R.; Martinez, Noelle; Sandquist, Darren

    2015-01-01

    The N cycle of arid ecosystems is influenced by low soil organic matter, high soil pH, and extremes in water potential and temperature that lead to open canopies and development of biological soil crusts (biocrusts). We investigated the effects of N amendment on soil microbial dynamics in a Larrea tridentata-Ambrosia dumosa shrubland site in southern Nevada USA. Sites were fertilized with a NO3-NH4 mix at 0, 7, and 15 kg N ha-1 y-1 from March 2012 to March 2013. In March 2013, biocrust (0–0.5 cm) and bulk soils (0–10 cm) were collected beneath Ambrosia canopies and in the interspaces between plants. Biomass responses were assessed as bacterial and fungal SSU rRNA gene copy number and chlorophyll a concentration. Metabolic responses were measured by five ecoenzyme activities and rates of N transformation. By most measures, nutrient availability, microbial biomass, and process rates were greater in soils beneath the shrub canopy compared to the interspace between plants, and greater in the surface biocrust horizon compared to the deeper 10 cm soil profile. Most measures responded positively to experimental N addition. Effect sizes were generally greater for bulk soil than biocrust. Results were incorporated into a meta-analysis of arid ecosystem responses to N amendment that included data from 14 other studies. Effect sizes were calculated for biomass and metabolic responses. Regressions of effect sizes, calculated for biomass, and metabolic responses, showed similar trends in relation to N application rate and N load (rate × duration). The critical points separating positive from negative treatment effects were 88 kg ha-1 y-1 and 159 kg ha-1, respectively, for biomass, and 70 kg ha-1 y-1 and 114 kg ha-1, respectively, for metabolism. These critical values are comparable to those for microbial biomass, decomposition rates and respiration reported in broader meta-analyses of N amendment effects in mesic ecosystems. However, large effect sizes at low N addition

  19. Effect of rock fragment addition on hydro-dispersive properties of compacted soils

    NASA Astrophysics Data System (ADS)

    Gargiulo, Laura; Mele, Giacomo; Coppola, Antonio; De Mascellis, Roberto; Di Matteo, Bruno; Terribile, Fabio; Basile, Angelo

    2014-05-01

    Compaction of agricultural soils is an increasingly challenging problem for crop production and environment. Mechanization of agricultural practices is one of the main factors inducing degradation of soil structure, especially in fragile soils with little organic matter and low shrinking-swelling capacity. Moreover, rock picking from stony soils is a routine practice to avoid tillage problems in some agricultural productions, but stone removal can significantly increase soil compaction, which lowers water infiltration rates and increases surface runoff and soil erosion. The practice of crushing and returning smaller rock fragments to the field could reduce the above problems. The aim of this work was to test the addition of rock fragments as practice to restore soil physical quality of not-stony soils susceptible to compaction. We carried out a lab experiment mixing five different volume concentrations (5%, 10%, 15%, 25% and 35%) of 4-8mm rock fragments with an Alfisol and an Entisol, showing compact structure and water stagnation problems in field. The repacked samples have undergone nine wet/dry cycles in order to induce soil structure formation and its stabilization. Bulk density, porosity and soil hydraulic properties and hydro-dispersive characteristics were measured. Soil hydraulic properties, namely water retention and hydraulic conductivity, were inferred from an infiltration experiment performed by a tension infiltrometer disc coupled with an inverse parameter estimation method; hydro-dispersive characteristics were performed from a tracer inflow-outflow experiment conducted in unsaturated condition, followed by the analysis of the breakthrough curve. Soil image analysis was used to enhance parameterization of the hydrological models near saturation. Preliminary results showed that bulk density significantly changed only after addition of 35% of rock fragments and a good physical restoration was reached at 15% volume concentration in Entisol and at 25% in

  20. 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.

  1. Effects of soil warming and nitrogen addition on soil respiration in a New Zealand tussock grassland.

    PubMed

    Graham, Scott L; Hunt, John E; Millard, Peter; McSeveny, Tony; Tylianakis, Jason M; Whitehead, David

    2014-01-01

    Soil respiration (RS) represents a large terrestrial source of CO2 to the atmosphere. Global change drivers such as climate warming and nitrogen deposition are expected to alter the terrestrial carbon cycle with likely consequences for RS and its components, autotrophic (RA) and heterotrophic respiration (RH). Here we investigate the impacts of a 3°C soil warming treatment and a 50 kg ha(-1) y(-1) nitrogen addition treatment on RS, RH and their respective seasonal temperature responses in an experimental tussock grassland. Average respiration in untreated soils was 0.96±0.09 μmol m(-2) s(-1) over the course of the experiment. Soil warming and nitrogen addition increased RS by 41% and 12% respectively. These treatment effects were additive under combined warming and nitrogen addition. Warming increased RH by 37% while nitrogen addition had no effect. Warming and nitrogen addition affected the seasonal temperature response of RS by increasing the basal rate of respiration (R10) by 14% and 20% respectively. There was no significant interaction between treatments for R10. The treatments had no impact on activation energy (E0). The seasonal temperature response of RH was not affected by either warming or nitrogen addition. These results suggest that the additional CO2 emissions from New Zealand tussock grassland soils as a result of warming-enhanced RS constitute a potential positive feedback to rising atmospheric CO2 concentration.

  2. 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.

  3. Planning Considerations Related to Collecting and Analyzing Samples of the Martian Soils

    NASA Technical Reports Server (NTRS)

    Liu, Yang; Mellon, Mike T.; Ming, Douglas W.; Morris, Richard V.; Noble, Sarah K.; Sullivan, Robert J.; Taylor, Lawrence A.; Beaty, David W.

    2014-01-01

    The Mars Sample Return (MSR) End-to-End International Science Analysis Group (E2E-iSAG [1]) established scientific objectives associ-ated with Mars returned-sample science that require the return and investigation of one or more soil samples. Soil is defined here as loose, unconsolidated materials with no implication for the presence or absence of or-ganic components. The proposed Mars 2020 (M-2020) rover is likely to collect and cache soil in addition to rock samples [2], which could be followed by future sample retrieval and return missions. Here we discuss key scientific consid-erations for sampling and caching soil samples on the proposed M-2020 rover, as well as the state in which samples would need to be preserved when received by analysts on Earth. We are seeking feedback on these draft plans as input to mission requirement formulation. A related planning exercise on rocks is reported in an accompanying abstract [3].

  4. Changes of pore systems and infiltration analysis in two degraded soils after rock fragment addition

    NASA Astrophysics Data System (ADS)

    Gargiulo, Laura; Coppola, Antonio; De Mascellis, Roberto; Basile, Angelo; Mele, Giacomo; Terribile, Fabio

    2015-04-01

    Many soils in arid and semi-arid environments contain high amounts of rock fragments as a result of both natural soil forming processes and human activities. The amount, dimension and shape of rock fragment strongly influence soil structure development and therefore many soil processes (e.g. infiltration, water storage, solute transport, etc.). The aim of this work was to test the effects on both infiltration process and soil pore formation following an addition of rock fragments. The test was performed on two different soils: a clayey soil (Alfisol) and a clay loamy soil (Entisol) showing both a natural compact structure and water stagnation problems in field. Three concentrations of 4-8mm rock fragments (15%, 25% and 35%) were added to air-dried soils and the repacked samples have been subject to nine wet/dry cycles in order to induce soil structure formation and its stabilization. The process of infiltration was monitored at -12 cm of pressure heads imposed at the soil surface and kept constant for a certain time by a tension infiltrometer. Moreover, k(h) was determined imposing -9, -6,-3 and -1 cm at soil surface and applying a steady-state solution. After the hydrological measurements the soil samples were resin-impregnated and images of vertical sections of the samples, acquired at 20µm resolution, were analyzed in order to quantify the pore size distribution. This latter was calculated using the "successive opening" approach. The Entisol samples showed similar infiltration curves I(t) among the 4 treatments, with higher percentage of stones (i.e. 25 and 35%) showing a faster rising in the early-time (< 2 min) infiltration; the Alfisol samples are spread, showing a higher variability: limiting the analysis to the first three, despite they show a similar shape, the higher the stones content the lower the cumulated infiltration. The behavior of the 35% sample diverges from the others: it shows a fast rising step at the very early time (< 2 min) followed by a

  5. Additional sampling directions improve detection range of wireless radiofrequency probes

    PubMed Central

    Mada, Marius; Carpenter, T. Adrian; Sawiak, Stephen J.; Williams, Guy B.

    2015-01-01

    Purpose While MRI is enhancing our knowledge about the structure and function of the human brain, subject motion remains a problem in many clinical applications. Recently, the use of wireless radiofrequency markers with three one‐dimensional (1D) navigators for prospective correction was demonstrated. This method is restricted in the range of motion that can be corrected, however, because of limited information in the 1D readouts. Methods Here, the limitation of techniques for disambiguating marker locations was investigated. It was shown that including more sampling directions extends the tracking range for head rotations. The efficiency of trading readout resolution for speed was explored. Results Tracking of head rotations was demonstrated from −19.2 to 34.4°, −2.7 to 10.0°, and −60.9 to 70.9° in the x‐, y‐, and z‐directions, respectively. In the presence of excessive head motion, the deviation of marker estimates from SPM8 was reduced by 17.1% over existing three‐projection methods. This was achieved by using an additional seven directions, extending the time needed for readouts by a factor of 3.3. Much of this increase may be circumvented by reducing resolution, without compromising accuracy. Conclusion Including additional sampling directions extends the range in which markers can be used, for patients who move a lot. Magn Reson Med 76:913–918, 2016. © 2015 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. PMID:26418189

  6. Analysis and Modeling of soil hydrology under different soil additives in artificial runoff plots

    NASA Astrophysics Data System (ADS)

    Ruidisch, M.; Arnhold, S.; Kettering, J.; Huwe, B.; Kuzyakov, Y.; Ok, Y.; Tenhunen, J. D.

    2009-12-01

    The impact of monsoon events during June and July in the Korean project region Haean Basin, which is located in the northeastern part of South Korea plays a key role for erosion, leaching and groundwater pollution risk by agrochemicals. Therefore, the project investigates the main hydrological processes in agricultural soils under field and laboratory conditions on different scales (plot, hillslope and catchment). Soil hydrological parameters were analysed depending on different soil additives, which are known for prevention of soil erosion and nutrient loss as well as increasing of water infiltration, aggregate stability and soil fertility. Hence, synthetic water-soluble Polyacrylamides (PAM), Biochar (Black Carbon mixed with organic fertilizer), both PAM and Biochar were applied in runoff plots at three agricultural field sites. Additionally, as control a subplot was set up without any additives. The field sites were selected in areas with similar hillslope gradients and with emphasis on the dominant land management form of dryland farming in Haean, which is characterised by row planting and row covering by foil. Hydrological parameters like satured water conductivity, matrix potential and water content were analysed by infiltration experiments, continuous tensiometer measurements, time domain reflectometry as well as pressure plates to indentify characteristic water retention curves of each horizon. Weather data were observed by three weather stations next to the runoff plots. Measured data also provide the input data for modeling water transport in the unsatured zone in runoff plots with HYDRUS 1D/2D/3D and SWAT (Soil & Water Assessment Tool).

  7. 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...

  8. Influence of residue and nitrogen fertilizer additions on carbon mineralization in soils with different texture and cropping histories

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To improve our ability to predict SOC mineralization response to residue and N additions in soils with different inherent and dynamic organic matter properties, a 330-day incubation was conducted using soil sampled from two long-term experiments (clay loam Mollisols in Iowa [IAsoil] and silt loam Ul...

  9. Effects of bagasse-charcoal addition to soil on nitrate leaching in calcaric soils

    NASA Astrophysics Data System (ADS)

    Kameyama, K.; Miyamoto, T.; Shinogi, Y.

    2009-12-01

    Nitrate leaching in soils is often an important aspect in agriculture. Nitrate is leached from the root zone, where plants can utilize them, by surplus rainfall because little nitrate is absorbed by soil colloids. Miyako Island (target area) is located in the subtropical zone and comprised of coral limestone with high permeability. Land surface is covered with calcaric dark red soil that is called “Shimajiri-Maji”. Since the soil has low water- and fertilizer-retaining capacity, fertilizer-derived nitrogen easily leaches from the root zone during surplus rainfall and the nitrogen utilization efficiency of crops is relatively low. Biochars, charcoal produced from pyrolysis of biomass, are known to adsorb dissolved nitrate. Sugarcane bagasse is the main biomass resource on the island because agriculture is the main industry on the island and sugarcane is cultivated in approximately 70% of the farmland. However, the adsorption characteristics of bagasse-charcoals for nitrate have not yet been clarified. The objective of this study was to evaluate the dependency of carbonization temperatures on the nitrate adsorption properties of bagasse-charcoals and the effects of bagasse-charcoal addition to the soil on NO3-N transport in the soil for optimal use of bagasse-charcoal as a soil amendment in Miyako Island. Sugarcane bagasse were air-dried and heated in a batch-type carbonization furnace at five different carbonization temperatures (400, 500, 600, 700 and 800°C) with a holding time of 2 h. Nitrate adsorption by soil and bagasse-charcoals at each carbonization temperature was measured by the batch equilibrium technique. NO3-N transport behavior in charcoal-amended soils (rates of charcoal addition: 0, 5 and 10 wt %) was evaluated in the column experiments. The breakthrough curves of NO3-N concentrations in the effluents from the bottom of the columns were analyzed with a convective-dispersion model. The model described one-dimensional transport of a sorbing solute

  10. 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...

  11. [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.

  12. 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.

  13. 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.

  14. Reduced plant uptake of pesticides with biochar additions to soil.

    PubMed

    Yu, Xiang-Yang; Ying, Guang-Guo; Kookana, Rai S

    2009-07-01

    We investigated the effectiveness of two types of biochars in reducing the bioavailability of two soil-applied insecticides (chlorpyrifos and carbofuran) to Spring onion (Allium cepa). The biochars prepared from the pyrolysis of Eucalyptus spp. wood chips at 450 and 850 degrees C (BC850) were thoroughly mixed into the soil to achieve 0%, 0.1%, 0.5% and 1% by soil weight. A spring onion crop was grown for 5 wk in the biochar-amended soils spiked with 50 mgkg(-1) of each pesticide. The loss of both pesticides due to degradation and or sequestration in soils decreased significantly with increasing amounts of biochars in soil. Over 35 d, 86-88% of the pesticides were lost from the control soil, whereas it was only 51% of carbofuran and 44% of chlorpyrifos from the soil amended with 1.0% BC850. Despite greater persistence of the pesticide residues in biochar-amended soils, the plant uptake of pesticides decreased markedly with increasing biochar content of the soil. With 1% of BC850 soil amendment, the total plant residues for chlorpyrifos and carbofuran decreased to 10% and 25% of that in the control treatment, respectively. The BC850 was particularly effective in reducing phytoavailability of both pesticides from soil, due to its high affinity for and ability to sequester pesticide residues.

  15. Soil quality changes after topsoil addition to eroded land

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil-landscape rehabilitation within eroded fields can be accomplished by moving topsoil from depositional to eroded landscape positions. The purpose is to improve soil quality and productivity of the upper root zone in eroded areas of the field. Changes in soil quality may be estimated through chan...

  16. Reduced plant uptake of pesticides with biochar additions to soil.

    PubMed

    Yu, Xiang-Yang; Ying, Guang-Guo; Kookana, Rai S

    2009-07-01

    We investigated the effectiveness of two types of biochars in reducing the bioavailability of two soil-applied insecticides (chlorpyrifos and carbofuran) to Spring onion (Allium cepa). The biochars prepared from the pyrolysis of Eucalyptus spp. wood chips at 450 and 850 degrees C (BC850) were thoroughly mixed into the soil to achieve 0%, 0.1%, 0.5% and 1% by soil weight. A spring onion crop was grown for 5 wk in the biochar-amended soils spiked with 50 mgkg(-1) of each pesticide. The loss of both pesticides due to degradation and or sequestration in soils decreased significantly with increasing amounts of biochars in soil. Over 35 d, 86-88% of the pesticides were lost from the control soil, whereas it was only 51% of carbofuran and 44% of chlorpyrifos from the soil amended with 1.0% BC850. Despite greater persistence of the pesticide residues in biochar-amended soils, the plant uptake of pesticides decreased markedly with increasing biochar content of the soil. With 1% of BC850 soil amendment, the total plant residues for chlorpyrifos and carbofuran decreased to 10% and 25% of that in the control treatment, respectively. The BC850 was particularly effective in reducing phytoavailability of both pesticides from soil, due to its high affinity for and ability to sequester pesticide residues. PMID:19419749

  17. [Effects of nitrogen addition on soil physico-chemical properties and enzyme activities in desertified steppe].

    PubMed

    Su, Jie-Qiong; Li, Xin-Rong; Bao, Jing-Ting

    2014-03-01

    To investigate the impacts of nitrogen (N) enrichment on soil physico-chemical property and soil enzyme activities in desert ecosystems, a field experiment by adding N at 0, 1.75, 3.5, 7, or 14 g N x m(-2) a(-1) was conducted in a temperate desert steppe in the southeastern fringe of the Tengger Desert. The results showed that N addition led to accumulations of total N, NO(3-)-N, NH(4+)-N, and available N in the upper soil (0-10 cm) and subsoil (10-20 cm), however, reductions in soil pH were observed, causing soil acidification to some extent. N addition pronouncedly inhibited soil enzyme activities, which were different among N addition levels, soil depths, and years, respectively. Soil enzyme activities were significantly correlated with the soil N level, soil pH, and soil moisture content, respectively.

  18. 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

  19. 21 CFR 71.4 - Samples; additional information.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... respect to the safety of the color additive or the physical or technical effect it produces. The date used for computing the 90-day limit for the purposes of section 721(d)(1) of the act shall be moved...

  20. 21 CFR 71.4 - Samples; additional information.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... respect to the safety of the color additive or the physical or technical effect it produces. The date used for computing the 90-day limit for the purposes of section 721(d)(1) of the act shall be moved...

  1. 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

  2. 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.

  3. 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

  4. 52 additional reference population samples for the 55 AISNP panel.

    PubMed

    Pakstis, Andrew J; Haigh, Eva; Cherni, Lotfi; ElGaaied, Amel Ben Ammar; Barton, Alison; Evsanaa, Baigalmaa; Togtokh, Ariunaa; Brissenden, Jane; Roscoe, Janet; Bulbul, Ozlem; Filoglu, Gonul; Gurkan, Cemal; Meiklejohn, Kelly A; Robertson, James M; Li, Cai-Xia; Wei, Yi-Liang; Li, Hui; Soundararajan, Usha; Rajeevan, Haseena; Kidd, Judith R; Kidd, Kenneth K

    2015-11-01

    Ancestry inference for a person using a panel of SNPs depends on the variation of frequencies of those SNPs around the world and the amount of reference data available for calculation/comparison. The Kidd Lab panel of 55 AISNPs has been incorporated in commercial kits by both Life Technologies and Illumina for massively parallel sequencing. Therefore, a larger set of reference populations will be useful for researchers using those kits. We have added reference population allele frequencies for 52 population samples to the 73 previously entered so that there are now allele frequencies publicly available in ALFRED and FROG-kb for a total of 125 population samples. PMID:26355664

  5. Compost addition reduces porosity and chlordecone transfer in soil microstructure.

    PubMed

    Woignier, Thierry; Clostre, Florence; Fernandes, Paula; Rangon, Luc; Soler, Alain; Lesueur-Jannoyer, Magalie

    2016-01-01

    Chlordecone, an organochlorine insecticide, pollutes soils and contaminates crops and water resources and is biomagnified by food chains. As chlordecone is partly trapped in the soil, one possible alternative to decontamination may be to increase its containment in the soil, thereby reducing its diffusion into the environment. Containing the pesticide in the soil could be achieved by adding compost because the pollutant has an affinity for organic matter. We hypothesized that adding compost would also change soil porosity, as well as transport and containment of the pesticide. We measured the pore features and studied the nanoscale structure to assess the effect of adding compost on soil microstructure. We simulated changes in the transport properties (hydraulic conductivity and diffusion) associated with changes in porosity. During compost incubation, the clay microstructure collapsed due to capillary stresses. Simulated data showed that the hydraulic conductivity and diffusion coefficient were reduced by 95 and 70% in the clay microstructure, respectively. Reduced transport properties affected pesticide mobility and thus helped reduce its transfer from the soil to water and to the crop. We propose that the containment effect is due not only to the high affinity of chlordecone for soil organic matter but also to a trapping mechanism in the soil porosity.

  6. Compost addition reduces porosity and chlordecone transfer in soil microstructure.

    PubMed

    Woignier, Thierry; Clostre, Florence; Fernandes, Paula; Rangon, Luc; Soler, Alain; Lesueur-Jannoyer, Magalie

    2016-01-01

    Chlordecone, an organochlorine insecticide, pollutes soils and contaminates crops and water resources and is biomagnified by food chains. As chlordecone is partly trapped in the soil, one possible alternative to decontamination may be to increase its containment in the soil, thereby reducing its diffusion into the environment. Containing the pesticide in the soil could be achieved by adding compost because the pollutant has an affinity for organic matter. We hypothesized that adding compost would also change soil porosity, as well as transport and containment of the pesticide. We measured the pore features and studied the nanoscale structure to assess the effect of adding compost on soil microstructure. We simulated changes in the transport properties (hydraulic conductivity and diffusion) associated with changes in porosity. During compost incubation, the clay microstructure collapsed due to capillary stresses. Simulated data showed that the hydraulic conductivity and diffusion coefficient were reduced by 95 and 70% in the clay microstructure, respectively. Reduced transport properties affected pesticide mobility and thus helped reduce its transfer from the soil to water and to the crop. We propose that the containment effect is due not only to the high affinity of chlordecone for soil organic matter but also to a trapping mechanism in the soil porosity. PMID:26250815

  7. 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.

  8. 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

  9. Soil aggregate stability as affected by clay mineralogy and polyacrylamide addition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The addition of polyacrylamide (PAM) to soil leads to stabilization of existing aggregates and improved bonding between, and aggregation of adjacent soil particles However, the dependence of PAM efficacy as an aggregate stabilizing agent on soil-clay mineralogy has not been studied. Sixteen soil sam...

  10. Response surface methodology for the microwave-assisted extraction of insecticides from soil samples.

    PubMed

    Hernández-Soriano, M Carmen; Peña, Aránzazu; Mingorance, M Dolores

    2007-09-01

    The extraction of two pyrethroid insecticides (deltamethrin and alpha-cypermethrin) together with three organophosphorus insecticides (dimethoate, diazinon and malathion) from soil samples was carried out with microwave-assisted technology. Experimental designs showed that extraction temperature, addition of water to the extractant and solvent/soil ratio were the variables that affected the recoveries of the pesticide the most. Response surface methodology was applied to find the optimum values of the variables involved in the extractions of the analytes. In addition, in order to achieve near-optimal extraction conditions, a desirability function was used to optimize the five pesticides simultaneously. The optimized conditions were applied to different types of soils.

  11. Improvement in day zero recoveries in field soil dissipation studies using larger diameter soil samples.

    PubMed

    Sharma, Ashok K; Strek, Harry J; Barefoot, Aldos C

    2014-05-01

    Obtaining acceptable recovery of the applied test substance at zero time in field soil dissipation studies has been a subject of considerable interest among scientists conducting regulatory field studies. In particular, achieving recoveries of ≥90% in soil samples collected immediately after applications in most studies has been elusive. This study investigated a modified soil sampling method, which could be used not only on day zero but for the entire study duration, to see if the recoveries in soil samples, especially in the early stages, can be improved. The modified sampling system has demonstrated that recoveries averaging 90% are possible and can be routinely obtained on day zero. Description of this modified sampling procedure and statistical analysis of the data collected for day zero samples are discussed.

  12. Use of passive sampling devices to determine soil contaminant concentrations

    SciTech Connect

    Johnson, K.A. |; Hooper, M.J.; Weisskopf, C.P.

    1996-12-31

    The effective remediation of contaminated sites requires accurate identification of chemical distributions. A rapid sampling method using passive sampling devices (PSDs) can provide a thorough site assessment. We have been pursuing their application in terrestrial systems and have found that they increase the ease and speed of analysis, decrease solvent usage and overall cost, and minimize the transport of contaminated soils. Time and cost savings allow a higher sampling frequency than is generally the case using traditional methods. PSDs have been used in the field in soils of varying physical properties and have been successful in estimating soil concentrations ranging from 1 {mu}g/kg (parts per billion) to greater than 200 mg/kg (parts per million). They were also helpful in identifying hot spots within the sites. Passive sampling devices show extreme promise as an analytical tool to rapidly characterize contaminant distributions in soil. There are substantial time and cost savings in laboratory personnel and supplies. By selectively excluding common interferences that require sample cleanup, PSDs can be retrieved from the field and processed rapidly (one technician can process approximately 90 PSDs in an 8-h work day). The results of our studies indicate that PSDs can be used to accurately estimate soil contaminant concentrations and provide lower detection limits. Further, time and cost savings will allow a more thorough and detailed characterization of contaminant distributions. 13 refs., 4 figs., 2 tabs.

  13. Stability of volatile organics in environmental soil samples. Final report

    SciTech Connect

    Maskarinec, M.P.; Bayne, C.K.; Jenkins, R.A.; Johnson, L.H.; Holladay, S.K.

    1992-11-01

    This report focuses on data generated for the purpose of establishing the stability of 19 volatile organic compounds in environmental soil samples. The study was carried out over a 56 day (for two soils) and a 111 day (for one reference soil) time frame and took into account as many variables as possible within the constraints of budget and time. The objectives of the study were: 1) to provide a data base which could be used to provide guidance on pre-analytical holding times for regulatory purposes; and 2) to provide a basis for the evaluation of data which is generated outside of the currently allowable holding times.

  14. Stability of volatile organics in environmental soil samples

    SciTech Connect

    Maskarinec, M.P.; Bayne, C.K.; Jenkins, R.A.; Johnson, L.H.; Holladay, S.K.

    1992-11-01

    This report focuses on data generated for the purpose of establishing the stability of 19 volatile organic compounds in environmental soil samples. The study was carried out over a 56 day (for two soils) and a 111 day (for one reference soil) time frame and took into account as many variables as possible within the constraints of budget and time. The objectives of the study were: 1) to provide a data base which could be used to provide guidance on pre-analytical holding times for regulatory purposes; and 2) to provide a basis for the evaluation of data which is generated outside of the currently allowable holding times.

  15. Changes in bacterial diversity and community structure following pesticides addition to soil estimated by cultivation technique.

    PubMed

    Cycoń, Mariusz; Piotrowska-Seget, Zofia

    2009-07-01

    An experiment was conducted under laboratory conditions to investigate the effect of increasing concentrations of fenitrothion (2, 10 and 200 mg a.i./kg soil), diuron (1.5, 7.5 and 150 mg a.i./kg soil) and thiram (3.5, 17.5 and 350 mg a.i./kg soil) on soil respiration, bacterial counts and changes in culturable fraction of soil bacteria. To ascertain these changes, the community structure, bacterial biodiversity and process of colony formation, based on the r/K strategy concept, EP- and CD-indices and the FOR model, respectively, were determined. The results showed that the measured parameters were generally unaffected by the lowest dosages of pesticides, corresponding to the recommended field rates. The highest dosages of fenitrothion and thiram suppressed the peak SIR by 15-70% and 20-80%, respectively, while diuron increased respiration rate by 17-25% during the 28-day experiment. Also, the total numbers of bacteria increased in pesticide-treated soils. However, the reverse effect on day 1 and, in addition, in case of the highest dosages of insecticide on days 14 and 28, was observed. Analysis of the community structure revealed that in all soil treatments bacterial communities were generally dominated by K-strategists. Moreover, differences in the distribution of individual bacteria classes and the gradual domination of bacteria populations belonging to r-strategists during the experiment, as compared to control, was observed. However, on day 1, at the highest pesticide dosages, fast growing bacteria constituted only 1-10% of the total colonies number during 48 h of plate incubation, whereas in remaining samples they reached from 20 to 40% of total cfu. This effect, in case of fenitrothion, lasted till the end of the experiment. At the highest dosages of fenitrothion, diuron and at all dosages of thiram the decrease of biodiversity, as indicated by EP- and CD-indices on day 1, was found. At the next sampling time, no significant retarding or stimulating effect

  16. Effects of soil temperature, flooding, and organic matter addition on N2O emissions from a soil of Hongze Lake wetland, China.

    PubMed

    Lu, Yan; Xu, Hongwen

    2014-01-01

    The objectives of this study were to test the effects of soil temperature, flooding, and raw organic matter input on N2O emissions in a soil sampled at Hongze Lake wetland, Jiangsu Province, China. The treatments studied were-peat soil (I), peat soil under flooding (II), peat soil plus raw organic matter (III), and peat soil under flooding plus organic matter. These four treatments were incubated at 20°C and 35°C. The result showed that temperature increase could enhance N2O emissions rate and cumulative emissions significantly; moreover, the flooded soil with external organic matter inputs showed the lowest cumulative rise in N2O emissions due to temperature increment. Flooding might inhibit soil N2O emissions, and the inhibition was more pronounced after organic matter addition to the original soil. Conversely, organic matter input explained lower cumulative N2O emissions under flooding. Our results suggest that complex interactions between flooding and other environmental factors might appear in soil N2O emissions. Further studies are needed to understand potential synergies or antagonisms between environmental factors that control N2O emissions in wetland soils.

  17. Effects of soil temperature, flooding, and organic matter addition on N2O emissions from a soil of Hongze Lake wetland, China.

    PubMed

    Lu, Yan; Xu, Hongwen

    2014-01-01

    The objectives of this study were to test the effects of soil temperature, flooding, and raw organic matter input on N2O emissions in a soil sampled at Hongze Lake wetland, Jiangsu Province, China. The treatments studied were-peat soil (I), peat soil under flooding (II), peat soil plus raw organic matter (III), and peat soil under flooding plus organic matter. These four treatments were incubated at 20°C and 35°C. The result showed that temperature increase could enhance N2O emissions rate and cumulative emissions significantly; moreover, the flooded soil with external organic matter inputs showed the lowest cumulative rise in N2O emissions due to temperature increment. Flooding might inhibit soil N2O emissions, and the inhibition was more pronounced after organic matter addition to the original soil. Conversely, organic matter input explained lower cumulative N2O emissions under flooding. Our results suggest that complex interactions between flooding and other environmental factors might appear in soil N2O emissions. Further studies are needed to understand potential synergies or antagonisms between environmental factors that control N2O emissions in wetland soils. PMID:25133216

  18. The influence of compost addition on the water repellency of brownfield soils

    NASA Astrophysics Data System (ADS)

    Whelan, Amii; Kechavarzi, Cedric; Sakrabani, Ruben; Coulon, Frederic; Simmons, Robert; Wu, Guozhong

    2010-05-01

    Compost application to brownfield sites, which can facilitate the stabilisation and remediation of contaminants whilst providing adequate conditions for plant growth, is seen as an opportunity to divert biodegradable wastes from landfill and put degraded land back into productive use. However, although compost application is thought to improve soil hydraulic functioning, there is a lack of information on the impact of large amounts of compost on soil water repellency. Water repellency in soils is attributed to the accumulation of hydrophobic organic compounds released as root exudates, fungal and microbial by-products and decomposition of organic matter. It has also been shown that brownfield soils contaminated with petroleum-derived organic contaminants can exhibit strong water repellency, preventing the rapid infiltration of water and leading potentially to surface run off and erosion of contaminated soil. However, hydrophobic organic contaminants are known to become sequestrated by partitioning into organic matter or diffusing into nano- and micropores, making them less available over time (ageing). The effect of large amounts of organic matter addition through compost application on the water repellency of soils contaminated with petroleum-derived organic contaminants requires further investigation. We characterised the influence of compost addition on water repellency in the laboratory by measuring the Water Drop Penetration Time (WDPT), sorptivity and water repellency index through infiltration experiments on soil samples amended with two composts made with contrasting feedstocks (green waste and predominantly meat waste). The treatments consisted of a sandy loam, a clay loam and a sandy loam contaminated with diesel fuel and aged for 3 years, which were amended with the two composts at a rate equivalent to 750t/ha. In addition core samples collected from a brownfield site, amended with compost at three different rates (250, 500 and 750t/ha) in 2007, were

  19. Analysis of procedures for sampling contaminated soil using Gy's Sampling Theory and Practice.

    PubMed

    Boudreault, Jean-Philippe; Dubé, Jean-Sébastien; Sona, Mirela; Hardy, Eric

    2012-05-15

    Soil sampling is a critical step in environmental site assessment studies. The representativeness of soil samples has a direct influence on financial, liability, environmental and public health issues associated with the outcome of remediation activities. Representativeness must be quantified for assessing and designing soil sampling procedures. Gy's Sampling Theory and Practice (STP) was used to analyze the reproducibility of two soil sampling procedures, namely a procedure based on grab sampling (GSP) and an alternative procedure (ASP) developed from STP principles. Sampling reproducibility, a component of sampling representativeness, was determined by theoretical calculations and experimental measurement of relative variances in trace metals concentrations at each stage of both sampling procedures. The ASP significantly increased the reproducibility of soil sampling compared to the GSP. Larger relative variances occurred during field sampling for the ASP and during laboratory sampling for the GSP. They were due to subsample mass reduction without control over particle size. Relative theoretical and experimental variances were in agreement. However, large discrepancies were observed for all sampling stages of both procedures between absolute theoretical and experimental relative variances. In the case of Pb, theoretical calculations were closer to experimental measurements when using a calculated value of the liberation factor (l) based on mineralogical data rather than l=1. It was shown that the b-exponent had a large influence on theoretical variances. Increasing the estimate of b from 0.5 to 1 largely improved the agreement between theory and experiment. Finally, 99% of experimental relative variance was explained by sampling errors compared to analytical errors.

  20. GICHD Mine Dog Testing Project - Soil Sample Results No.3

    SciTech Connect

    PHELAN, JAMES M.; BARNETT, JAMES L.; BENDER, SUSAN FAE ANN; ARCHULETA, LUISA M.

    2003-03-01

    A mine dog evaluation project initiated by the Geneva International Center for Humanitarian Demining is evaluating the capability and reliability of mine detection dogs. The performance of field-operational mine detection dogs will be measured in test minefields in Afghanistan and Bosnia containing actual, but unfused landmines. Repeated performance testing over two years through various seasonal weather conditions will provide data simulating near real world conditions. Soil samples will be obtained adjacent to the buried targets repeatedly over the course of the test. Chemical analysis results from these soil samples will be used to evaluate correlations between mine dog detection performance and seasonal weather conditions. This report documents the analytical chemical methods and results from the third batch of soils received. This batch contained samples from Kharga, Afghanistan collected in October 2002.

  1. GICHD mine dog testing project - soil sample results #4.

    SciTech Connect

    Barnett, James L.; Phelan, James M.; Archuleta, Luisa M.; Wood, Tyson B.; Donovan, Kelly L.; Bender, Susan Fae Ann

    2003-08-01

    A mine dog evaluation project initiated by the Geneva International Center for Humanitarian Demining is evaluating the capability and reliability of mine detection dogs. The performance of field-operational mine detection dogs will be measured in test minefields in Afghanistan and Bosnia containing actual, but unfused landmines. Repeated performance testing over two years through various seasonal weather conditions will provide data simulating near real world conditions. Soil samples will be obtained adjacent to the buried targets repeatedly over the course of the test. Chemical analysis results from these soil samples will be used to evaluate correlations between mine dog detection performance and seasonal weather conditions. This report documents the analytical chemical methods and results from the fourth batch of soils received. This batch contained samples from Kharga, Afghanistan collected in April 2003 and Sarajevo, Bosnia collected in May 2003.

  2. GICHD mine dog testing project : soil sample results #5.

    SciTech Connect

    Barnett, James L.; Phelan, James M.; Archuleta, Luisa M.; Donovan, Kelly L.; Bender, Susan Fae Ann

    2004-01-01

    A mine dog evaluation project initiated by the Geneva International Center for Humanitarian Demining is evaluating the capability and reliability of mine detection dogs. The performance of field-operational mine detection dogs will be measured in test minefields in Afghanistan containing actual, but unfused landmines. Repeated performance testing over two years through various seasonal weather conditions will provide data simulating near real world conditions. Soil samples will be obtained adjacent to the buried targets repeatedly over the course of the test. Chemical analysis results from these soil samples will be used to evaluate correlations between mine dog detection performance and seasonal weather conditions. This report documents the analytical chemical methods and results from the fifth batch of soils received. This batch contained samples from Kharga, Afghanistan collected in June 2003.

  3. Radon exhalation rates from some soil samples of Kharar, Punjab

    SciTech Connect

    Mehta, Vimal; Singh, Tejinder Pal; Chauhan, R. P.; Mudahar, G. S.

    2015-08-28

    Radon and its progeny are major contributors in the radiation dose received by general population of the world. Because radon is a noble gas, a large portion of it is free to migrate away from radium. The primary sources of radon in the houses are soils and rocks source emanations, emanation from building materials, and entry of radon into a structure from outdoor air. Keeping this in mind the study of radon exhalation rate from some soil samples of the Kharar, Punjab has been carried out using Can Technique. The equilibrium radon concentration in various soil samples of Kharar area of district Mohali varied from 12.7 Bqm{sup −3} to 82.9 Bqm{sup −3} with an average of 37.5 ± 27.0 Bqm{sup −3}. The radon mass exhalation rates from the soil samples varied from 0.45 to 2.9 mBq/kg/h with an average of 1.4 ± 0.9 mBq/kg/h and radon surface exhalation rates varied from 10.4 to 67.2 mBq/m{sup 2}/h with an average of 30.6 ± 21.8 mBq/m{sup 2}/h. The radon mass and surface exhalation rates of the soil samples of Kharar, Punjab were lower than that of the world wide average.

  4. Radon exhalation rates from some soil samples of Kharar, Punjab

    NASA Astrophysics Data System (ADS)

    Mehta, Vimal; Singh, Tejinder Pal; Chauhan, R. P.; Mudahar, G. S.

    2015-08-01

    Radon and its progeny are major contributors in the radiation dose received by general population of the world. Because radon is a noble gas, a large portion of it is free to migrate away from radium. The primary sources of radon in the houses are soils and rocks source emanations, emanation from building materials, and entry of radon into a structure from outdoor air. Keeping this in mind the study of radon exhalation rate from some soil samples of the Kharar, Punjab has been carried out using Can Technique. The equilibrium radon concentration in various soil samples of Kharar area of district Mohali varied from 12.7 Bqm-3 to 82.9 Bqm-3 with an average of 37.5 ± 27.0 Bqm-3. The radon mass exhalation rates from the soil samples varied from 0.45 to 2.9 mBq/kg/h with an average of 1.4 ± 0.9 mBq/kg/h and radon surface exhalation rates varied from 10.4 to 67.2 mBq/m2/h with an average of 30.6 ± 21.8 mBq/m2/h. The radon mass and surface exhalation rates of the soil samples of Kharar, Punjab were lower than that of the world wide average.

  5. Divergent Effects of Nitrogen Addition on Soil Respiration in a Semiarid Grassland

    PubMed Central

    Zhu, Cheng; Ma, Yiping; Wu, Honghui; Sun, Tao; La Pierre, Kimberly J.; Sun, Zewei; Yu, Qiang

    2016-01-01

    Nitrogen (N) deposition has been steadily increasing for decades, with consequences for soil respiration. However, we have a limited understanding of how soil respiration responds to N availability. Here, we investigated the soil respiration responses to low and high levels of N addition (0.4 mol N m−2 yr−1 vs 1.6 mol N m−2 yr−1) over a two-year period in a semiarid Leymus chinensis grassland in Inner Mongolia, China. Our results show that low-level N addition increased soil respiration, plant belowground biomass and soil microbial biomass carbon (MBC), while high-level N additions decreased them. Soil respiration was positively correlated with plant belowground biomass, MBC, soil temperature and soil moisture. Together plant belowground biomass and MBC explained 99.4% of variation in mean soil respiration, with plant belowground biomass explaining 63.4% of the variation and soil MBC explaining the remaining 36%. Finally, the temperature sensitivity of soil respiration was not influenced by N additions. Overall, our results suggest that low levels of N deposition may stimulate soil respiration, but large increases in N availability may decrease soil respiration, and that these responses are driven by the dissimilar responses of both plant belowground biomass and soil MBC. PMID:27629241

  6. Divergent Effects of Nitrogen Addition on Soil Respiration in a Semiarid Grassland.

    PubMed

    Zhu, Cheng; Ma, Yiping; Wu, Honghui; Sun, Tao; La Pierre, Kimberly J; Sun, Zewei; Yu, Qiang

    2016-01-01

    Nitrogen (N) deposition has been steadily increasing for decades, with consequences for soil respiration. However, we have a limited understanding of how soil respiration responds to N availability. Here, we investigated the soil respiration responses to low and high levels of N addition (0.4 mol N m(-2) yr(-1) vs 1.6 mol N m(-2) yr(-1)) over a two-year period in a semiarid Leymus chinensis grassland in Inner Mongolia, China. Our results show that low-level N addition increased soil respiration, plant belowground biomass and soil microbial biomass carbon (MBC), while high-level N additions decreased them. Soil respiration was positively correlated with plant belowground biomass, MBC, soil temperature and soil moisture. Together plant belowground biomass and MBC explained 99.4% of variation in mean soil respiration, with plant belowground biomass explaining 63.4% of the variation and soil MBC explaining the remaining 36%. Finally, the temperature sensitivity of soil respiration was not influenced by N additions. Overall, our results suggest that low levels of N deposition may stimulate soil respiration, but large increases in N availability may decrease soil respiration, and that these responses are driven by the dissimilar responses of both plant belowground biomass and soil MBC. PMID:27629241

  7. EG & G Mount Plant, December 1990 and January 1991, D & D soil box sampling

    SciTech Connect

    1991-04-01

    Six hundred eighty-two (682) containers of soil were generated at Mound Plant between April 1 and October 31, 1990 as a result of the excavation of soils containing plutonium-238 at two ongoing Decontamination and Decommissioning (D&D) Program sites; these areas are known as Area 14, the waste transfer system (WTS) hillside, and Area 17, the Special Metallurgical (SM) Building Area. The soils from these areas are part of the Mound Plant waste stream number AMDM-000000010, Contaminated Soil, and are proposed for shipment to the Nevada Test Site (NTS) for disposal as low-level radioactive waste. These containers of soil are currently in storage at Mound Plant. The purpose of this sampling and analysis was to demonstrate that the D&D soils comply with the waste acceptance requirements of the NTS, as presented In Nevada Test Site Defense Waste Acceptance Criteria, Certification, and Transfer Requirements (DOE 1988). The sealed waste packages, constructed of wood or metal, are currently being stored In Building 31 and at other locations throughout the Mound Plant. For additional historical information concerning the D&D soils, Including waste stream evaluations and past sampling data see the Sampling and Analysis Plan for Mound Plant D&D Soils Packages (EG&G 1991).

  8. Improved cryogenic coring device for sampling wetland soils

    SciTech Connect

    Cahoon, D.R.; Lynch, J.C.; Knaus, R.M.

    1996-09-01

    This paper is the third in a series on the design and construction (Knaus 1986) and improvements (Knaus and Cahoon 1990) of a cryogenic soil-coring device (cryocorer). Freezing wetland soils in place during sampling eliminates compaction, dewatering, and loss of flocculent material at the water-sediment interface. The cryocorer is suitable for sampling soils of emergent marsh and mangrove forests as well as shallow water bottoms, although it has been used primarily for the former. A small-diameter frozen soil core minimizes disruption of the surface, can be evaluated immediately for overall quality, and can be used to measure soil profiles and subsample for further analysis. The cryocorer continues to be used in studies of wetland accretion and soil bulk density throughout the US. Concomitant with the increased use of the device, improvements in cryocorer design and application have occurred. Reported here are improvements in design that have been made since 1992 with references to wetland research in which the cryocorer has been used extensively.

  9. Contamination of apple orchard soils and fruit trees with copper-based fungicides: sampling aspects.

    PubMed

    Wang, Quanying; Liu, Jingshuang; Liu, Qiang

    2015-01-01

    Accumulations of copper in orchard soils and fruit trees due to the application of Cu-based fungicides have become research hotspots. However, information about the sampling strategies, which can affect the accuracy of the following research results, is lacking. This study aimed to determine some sampling considerations when Cu accumulations in the soils and fruit trees of apple orchards are studied. The study was conducted in three apple orchards from different sites. Each orchard included two different histories of Cu-based fungicides usage, varying from 3 to 28 years. Soil samples were collected from different locations varying with the distances from tree trunk to the canopy drip line. Fruits and leaves from the middle heights of tree canopy at two locations (outer canopy and inner canopy) were collected. The variation in total soil Cu concentrations between orchards was much greater than the variation within orchards. Total soil Cu concentrations had a tendency to increase with the increasing history of Cu-based fungicides usage. Moreover, total soil Cu concentrations had the lowest values at the canopy drip line, while the highest values were found at the half distances between the trunk and the canopy drip line. Additionally, Cu concentrations of leaves and fruits from the outer parts of the canopy were significantly higher than from the inner parts. Depending on the findings of this study, not only the between-orchard variation but also the within-orchard variation should be taken into consideration when conducting future soil and tree samplings in apple orchards.

  10. Phase chemistry of Apollo 14 soil sample 14259

    NASA Technical Reports Server (NTRS)

    1974-01-01

    0.26 gm of Apollo 14 soil sample 14259 has been investigated by optical, X-ray diffraction and electron microprobe techniques. The mineral abundances in the soil are 45% plagioclase, 41% pyroxene, 7% olivine, 3% oxides, 2% K-feldspar, 1% nickel-iron and less than 1% troilite. Eleven percent of the glasses have compositions like those of mare basalts or mare soils and are believed to be mare-derived. Eighty-six percent of the glasses are equivalent in composition to basalts that have higher Al, and lower Ca/Al and Fe/Mg ratios than mare basalts. The most abundant compositional type is named Fra Mauro basaltic glass and is subdivided into three related types. The other major glass type in the soil corresponds in composition to anorthositic gabbro.

  11. RAPID SEPARATION METHOD FOR ACTINIDES IN EMERGENCY SOIL SAMPLES

    SciTech Connect

    Maxwell, S.; Culligan, B.; Noyes, G.

    2009-11-09

    A new rapid method for the determination of actinides in soil and sediment samples has been developed at the Savannah River Site Environmental Lab (Aiken, SC, USA) that can be used for samples up to 2 grams in emergency response situations. The actinides in soil method utilizes a rapid sodium hydroxide fusion method, a lanthanum fluoride soil matrix removal step, and a streamlined column separation process with stacked TEVA, TRU and DGA Resin cartridges. Lanthanum was separated rapidly and effectively from Am and Cm on DGA Resin. Vacuum box technology and rapid flow rates are used to reduce analytical time. Alpha sources are prepared using cerium fluoride microprecipitation for counting by alpha spectrometry. The method showed high chemical recoveries and effective removal of interferences. This new procedure was applied to emergency soil samples received in the NRIP Emergency Response exercise administered by the National Institute for Standards and Technology (NIST) in April, 2009. The actinides in soil results were reported within 4-5 hours with excellent quality.

  12. Soil mineral composition matters: response of microbial communities to phenanthrene and plant litter addition in long-term matured artificial soils.

    PubMed

    Babin, Doreen; Vogel, Cordula; Zühlke, Sebastian; Schloter, Michael; Pronk, Geertje Johanna; Heister, Katja; Spiteller, Michael; Kögel-Knabner, Ingrid; Smalla, Kornelia

    2014-01-01

    The fate of polycyclic aromatic hydrocarbons (PAHs) in soil is determined by a suite of biotic and abiotic factors, and disentangling their role in the complex soil interaction network remains challenging. Here, we investigate the influence of soil composition on the microbial community structure and its response to the spiked model PAH compound phenanthrene and plant litter. We used long-term matured artificial soils differing in type of clay mineral (illite, montmorillonite) and presence of charcoal or ferrihydrite. The soils received an identical soil microbial fraction and were incubated for more than two years with two sterile manure additions. The matured artificial soils and a natural soil were subjected to the following spiking treatments: (I) phenanthrene, (II) litter, (III) litter + phenanthrene, (IV) unspiked control. Total community DNA was extracted from soil sampled on the day of spiking, 7, 21, and 63 days after spiking. Bacterial 16S rRNA gene and fungal internal transcribed spacer amplicons were quantified by qPCR and subjected to denaturing gradient gel electrophoresis (DGGE). DGGE analysis revealed that the bacterial community composition, which was strongly shaped by clay minerals after more than two years of incubation, changed in response to spiked phenanthrene and added litter. DGGE and qPCR showed that soil composition significantly influenced the microbial response to spiking. While fungal communities responded only in presence of litter to phenanthrene spiking, the response of the bacterial communities to phenanthrene was less pronounced when litter was present. Interestingly, microbial communities in all artificial soils were more strongly affected by spiking than in the natural soil, which might indicate the importance of higher microbial diversity to compensate perturbations. This study showed the influence of soil composition on the microbiota and their response to phenanthrene and litter, which may increase our understanding of

  13. Soil Mineral Composition Matters: Response of Microbial Communities to Phenanthrene and Plant Litter Addition in Long-Term Matured Artificial Soils

    PubMed Central

    Babin, Doreen; Vogel, Cordula; Zühlke, Sebastian; Schloter, Michael; Pronk, Geertje Johanna; Heister, Katja; Spiteller, Michael; Kögel-Knabner, Ingrid; Smalla, Kornelia

    2014-01-01

    The fate of polycyclic aromatic hydrocarbons (PAHs) in soil is determined by a suite of biotic and abiotic factors, and disentangling their role in the complex soil interaction network remains challenging. Here, we investigate the influence of soil composition on the microbial community structure and its response to the spiked model PAH compound phenanthrene and plant litter. We used long-term matured artificial soils differing in type of clay mineral (illite, montmorillonite) and presence of charcoal or ferrihydrite. The soils received an identical soil microbial fraction and were incubated for more than two years with two sterile manure additions. The matured artificial soils and a natural soil were subjected to the following spiking treatments: (I) phenanthrene, (II) litter, (III) litter + phenanthrene, (IV) unspiked control. Total community DNA was extracted from soil sampled on the day of spiking, 7, 21, and 63 days after spiking. Bacterial 16S rRNA gene and fungal internal transcribed spacer amplicons were quantified by qPCR and subjected to denaturing gradient gel electrophoresis (DGGE). DGGE analysis revealed that the bacterial community composition, which was strongly shaped by clay minerals after more than two years of incubation, changed in response to spiked phenanthrene and added litter. DGGE and qPCR showed that soil composition significantly influenced the microbial response to spiking. While fungal communities responded only in presence of litter to phenanthrene spiking, the response of the bacterial communities to phenanthrene was less pronounced when litter was present. Interestingly, microbial communities in all artificial soils were more strongly affected by spiking than in the natural soil, which might indicate the importance of higher microbial diversity to compensate perturbations. This study showed the influence of soil composition on the microbiota and their response to phenanthrene and litter, which may increase our understanding of

  14. Mid-Level Soil Sample for Oven Number Seven

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Soil from a sample called Burning Coals was delivered through the doors of cell number seven (left) of the Thermal and Evolved-Gas Analyzer on NASA's Phoenix Mars Lander on Aug. 20, 2008, during the 85th Martian day, or sol, since Phoenix landed.

    This image from Phoenix's Robotic Arm Camera shows some of the soil on the screen beneath the doors. One of the cell's two doors is fully open, the other partially open.

    This soil sample comes from an intermediate depth between the ground surface and the hard, underground icy layer at the Phoenix site.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  15. Laboratory and Airborne BRDF Analysis of Vegetation Leaves and Soil Samples

    NASA Technical Reports Server (NTRS)

    Georgiev, Georgi T.; Gatebe, Charles K.; Butler, James J.; King, Michael D.

    2008-01-01

    Laboratory-based Bidirectional Reflectance Distribution Function (BRDF) analysis of vegetation leaves, soil, and leaf litter samples is presented. The leaf litter and soil samples, numbered 1 and 2, were obtained from a site located in the savanna biome of South Africa (Skukuza: 25.0degS, 31.5degE). A third soil sample, number 3, was obtained from Etosha Pan, Namibia (19.20degS, 15.93degE, alt. 1100 m). In addition, BRDF of local fresh and dry leaves from tulip tree (Liriodendron tulipifera) and acacia tree (Acacia greggii) were studied. It is shown how the BRDF depends on the incident and scatter angles, sample size (i.e. crushed versus whole leaf,) soil samples fraction size, sample status (i.e. fresh versus dry leaves), vegetation species (poplar versus acacia), and vegetation s biochemical composition. As a demonstration of the application of the results of this study, airborne BRDF measurements acquired with NASA's Cloud Absorption Radiometer (CAR) over the same general site where the soil and leaf litter samples were obtained are compared to the laboratory results. Good agreement between laboratory and airborne measured BRDF is reported.

  16. A CONCEPTUAL UNDERSTANDING OF LEAKAGE DURING SOIL-GAS SAMPLING

    EPA Science Inventory

    A heuristic model is developed to develop a conceptual understanding of leakage during soil-gas sampling. Leakage is shown to be simply a function of the permeability contrast between the formation and borehole and geometric factors. As the ratio of formation to borehole permea...

  17. FIELD SAMPLING OF RESIDUAL AVIATION GASOLINE IN SANDY SOIL

    EPA Science Inventory

    Two complimentary field sampling methods for the determination of residual aviation gasoline content in the contaminated capillary fringe of a fine, uniform, sandy soil were investigated. The first method featured filed extrusion of core barrels into pint size Mason jars, while ...

  18. A survey of scale insects in soil samples from Europe (Hemiptera, Coccomorpha).

    PubMed

    Kaydan, Mehmet Bora; Benedicty, Zsuzsanna Konczné; Kiss, Balázs; Szita, Éva

    2016-01-01

    In the last decades, several expeditions were organized in Europe by the researchers of the Hungarian Natural History Museum to collect snails, aquatic insects and soil animals (mites, springtails, nematodes, and earthworms). In this study, scale insect (Hemiptera: Coccomorpha) specimens extracted from Hungarian Natural History Museum soil samples (2970 samples in total), all of which were collected using soil and litter sampling devices, and extracted by Berlese funnel, were examined. From these samples, 43 scale insect species (Acanthococcidae 4, Coccidae 2, Micrococcidae 1, Ortheziidae 7, Pseudococcidae 21, Putoidae 1 and Rhizoecidae 7) were found in 16 European countries. In addition, a new species belonging to the family Pseudococcidae, Brevennia larvalis Kaydan, sp. n. and a new species of Ortheziidae, Ortheziola editae Szita & Konczné Benedicty, sp. n. are described and illustrated based on the adult female stage. Revised keys to the adult females of Brevennia and Ortheziola are presented.

  19. A survey of scale insects in soil samples from Europe (Hemiptera, Coccomorpha)

    PubMed Central

    Kaydan, Mehmet Bora; Benedicty, Zsuzsanna Konczné; Kiss, Balázs; Szita, Éva

    2016-01-01

    Abstract In the last decades, several expeditions were organized in Europe by the researchers of the Hungarian Natural History Museum to collect snails, aquatic insects and soil animals (mites, springtails, nematodes, and earthworms). In this study, scale insect (Hemiptera: Coccomorpha) specimens extracted from Hungarian Natural History Museum soil samples (2970 samples in total), all of which were collected using soil and litter sampling devices, and extracted by Berlese funnel, were examined. From these samples, 43 scale insect species (Acanthococcidae 4, Coccidae 2, Micrococcidae 1, Ortheziidae 7, Pseudococcidae 21, Putoidae 1 and Rhizoecidae 7) were found in 16 European countries. In addition, a new species belonging to the family Pseudococcidae, Brevennia larvalis Kaydan, sp. n. and a new species of Ortheziidae, Ortheziola editae Szita & Konczné Benedicty, sp. n. are described and illustrated based on the adult female stage. Revised keys to the adult females of Brevennia and Ortheziola are presented. PMID:27081335

  20. A survey of scale insects in soil samples from Europe (Hemiptera, Coccomorpha).

    PubMed

    Kaydan, Mehmet Bora; Benedicty, Zsuzsanna Konczné; Kiss, Balázs; Szita, Éva

    2016-01-01

    In the last decades, several expeditions were organized in Europe by the researchers of the Hungarian Natural History Museum to collect snails, aquatic insects and soil animals (mites, springtails, nematodes, and earthworms). In this study, scale insect (Hemiptera: Coccomorpha) specimens extracted from Hungarian Natural History Museum soil samples (2970 samples in total), all of which were collected using soil and litter sampling devices, and extracted by Berlese funnel, were examined. From these samples, 43 scale insect species (Acanthococcidae 4, Coccidae 2, Micrococcidae 1, Ortheziidae 7, Pseudococcidae 21, Putoidae 1 and Rhizoecidae 7) were found in 16 European countries. In addition, a new species belonging to the family Pseudococcidae, Brevennia larvalis Kaydan, sp. n. and a new species of Ortheziidae, Ortheziola editae Szita & Konczné Benedicty, sp. n. are described and illustrated based on the adult female stage. Revised keys to the adult females of Brevennia and Ortheziola are presented. PMID:27081335

  1. Molecular aspects of aromatic C additions to soils: Implications of biochar quality for ecosystem functionality

    EPA Science Inventory

    Solid residues of incomplete combustion (biochar or char) are continuously being added to soils due to natural vegetation fires in many ecosystems. However, new strategies for carbon sequestration in soils are likely to include the active addition of biochar to soils. Since bioc...

  2. RESPONSE OF SOIL MICROBIAL BIOMASS AND COMMUNITY COMPOSITION TO CHRONIC NITROGEN ADDITIONS AT HARVARD FOREST

    EPA Science Inventory

    Soil microbial communities may respond to anthropogenic increases in ecosystem nitrogen (N) availability, and their response may ultimately feedback on ecosystem carbon and N dynamics. We examined the long-term effects of chronic N additions on soil microbes by measuring soil mi...

  3. 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.

  4. Turnover of soil carbon pools following addition of switchgrass-derived biochar to four soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The amendment of soils with biochar may improve plant growth and sequester carbon, especially in marginal soils not suitable for the majority of commodity production. While biochar can persist in soils, it is not clear whether its persistence is affected by soil type. Moreover, we know little of how...

  5. Soil and leaf litter metaproteomics—a brief guideline from sampling to understanding

    PubMed Central

    Keiblinger, Katharina M.; Fuchs, Stephan; Zechmeister-Boltenstern, Sophie; Riedel, Katharina

    2016-01-01

    The increasing application of soil metaproteomics is providing unprecedented, in-depth characterization of the composition and functionality of in situ microbial communities. Despite recent advances in high-resolution mass spectrometry, soil metaproteomics still suffers from a lack of effective and reproducible protein extraction protocols and standardized data analyses. This review discusses the opportunities and limitations of selected techniques in soil-, and leaf litter metaproteomics, and presents a step-by-step guideline on their application, covering sampling, sample preparation, extraction and data evaluation strategies. In addition, we present recent applications of soil metaproteomics and discuss how such approaches, linking phylogenetics and functionality, can help gain deeper insights into terrestrial microbial ecology. Finally, we strongly recommend that to maximize the insights environmental metaproteomics may provide, such methods should be employed within a holistic experimental approach considering relevant aboveground and belowground ecosystem parameters.

  6. Soil and leaf litter metaproteomics—a brief guideline from sampling to understanding

    PubMed Central

    Keiblinger, Katharina M.; Fuchs, Stephan; Zechmeister-Boltenstern, Sophie; Riedel, Katharina

    2016-01-01

    The increasing application of soil metaproteomics is providing unprecedented, in-depth characterization of the composition and functionality of in situ microbial communities. Despite recent advances in high-resolution mass spectrometry, soil metaproteomics still suffers from a lack of effective and reproducible protein extraction protocols and standardized data analyses. This review discusses the opportunities and limitations of selected techniques in soil-, and leaf litter metaproteomics, and presents a step-by-step guideline on their application, covering sampling, sample preparation, extraction and data evaluation strategies. In addition, we present recent applications of soil metaproteomics and discuss how such approaches, linking phylogenetics and functionality, can help gain deeper insights into terrestrial microbial ecology. Finally, we strongly recommend that to maximize the insights environmental metaproteomics may provide, such methods should be employed within a holistic experimental approach considering relevant aboveground and belowground ecosystem parameters. PMID:27549116

  7. Geographic sampling of urban soils for contaminant mapping: how many samples and from where.

    PubMed

    Griffith, Daniel A

    2008-12-01

    Properly sampling soils and mapping soil contamination in urban environments requires that impacts of spatial autocorrelation be taken into account. As spatial autocorrelation increases in an urban landscape, the amount of duplicate information contained in georeferenced data also increases, whether an entire population or some type of random sample drawn from that population is being analyzed, resulting in conventional power and sample size calculation formulae yielding incorrect sample size numbers vis-à-vis model-based inference. Griffith (in Annals, Association of American Geographers, 95, 740-760, 2005) exploits spatial statistical model specifications to formulate equations for estimating the necessary sample size needed to obtain some predetermined level of precision for an analysis of georeferenced data when implementing a tessellation stratified random sampling design, labeling this approach model-informed, since a model of latent spatial autocorrelation is required. This paper addresses issues of efficiency associated with these model-based results. It summarizes findings from a data collection exercise (soil samples collected from across Syracuse, NY), as well as from a set of resampling and from a set of simulation experiments following experimental design principles spelled out by Overton and Stehman (in Communications in Statistics: Theory and Methods, 22, 2641-2660). Guidelines are suggested concerning appropriate sample size (i.e., how many) and sampling network (i.e., where).

  8. Seasonal Patterns of Soil Respiration and Related Soil Biochemical Properties under Nitrogen Addition in Winter Wheat Field.

    PubMed

    Liang, Guopeng; Houssou, Albert A; Wu, Huijun; Cai, Dianxiong; Wu, Xueping; Gao, Lili; Li, Jing; Wang, Bisheng; Li, Shengping

    2015-01-01

    Understanding the changes of soil respiration under increasing N fertilizer in cropland ecosystems is crucial to accurately predicting global warming. This study explored seasonal variations of soil respiration and its controlling biochemical properties under a gradient of Nitrogen addition during two consecutive winter wheat growing seasons (2013-2015). N was applied at four different levels: 0, 120, 180 and 240 kg N ha(-1) year(-1) (denoted as N0, N12, N18 and N24, respectively). Soil respiration exhibited significant seasonal variation and was significantly affected by soil temperature with Q10 ranging from 2.04 to 2.46 and from 1.49 to 1.53 during 2013-2014 and 2014-2015 winter wheat growing season, respectively. Soil moisture had no significant effect on soil respiration during 2013-2014 winter wheat growing season but showed a significant and negative correlation with soil respiration during 2014-2015 winter wheat growing season. Soil respiration under N24 treatment was significantly higher than N0 treatment. Averaged over the two growing seasons, N12, N18 and N24 significantly increased soil respiration by 13.4, 16.4 and 25.4% compared with N0, respectively. N addition also significantly increased easily extractable glomalin-related soil protein (EEG), soil organic carbon (SOC), total N, ammonium N and nitrate N contents. In addition, soil respiration was significantly and positively correlated with β-glucosidase activity, EEG, SOC, total N, ammonium N and nitrate N contents. The results indicated that high N fertilization improved soil chemical properties, but significantly increased soil respiration. PMID:26629695

  9. Seasonal Patterns of Soil Respiration and Related Soil Biochemical Properties under Nitrogen Addition in Winter Wheat Field.

    PubMed

    Liang, Guopeng; Houssou, Albert A; Wu, Huijun; Cai, Dianxiong; Wu, Xueping; Gao, Lili; Li, Jing; Wang, Bisheng; Li, Shengping

    2015-01-01

    Understanding the changes of soil respiration under increasing N fertilizer in cropland ecosystems is crucial to accurately predicting global warming. This study explored seasonal variations of soil respiration and its controlling biochemical properties under a gradient of Nitrogen addition during two consecutive winter wheat growing seasons (2013-2015). N was applied at four different levels: 0, 120, 180 and 240 kg N ha(-1) year(-1) (denoted as N0, N12, N18 and N24, respectively). Soil respiration exhibited significant seasonal variation and was significantly affected by soil temperature with Q10 ranging from 2.04 to 2.46 and from 1.49 to 1.53 during 2013-2014 and 2014-2015 winter wheat growing season, respectively. Soil moisture had no significant effect on soil respiration during 2013-2014 winter wheat growing season but showed a significant and negative correlation with soil respiration during 2014-2015 winter wheat growing season. Soil respiration under N24 treatment was significantly higher than N0 treatment. Averaged over the two growing seasons, N12, N18 and N24 significantly increased soil respiration by 13.4, 16.4 and 25.4% compared with N0, respectively. N addition also significantly increased easily extractable glomalin-related soil protein (EEG), soil organic carbon (SOC), total N, ammonium N and nitrate N contents. In addition, soil respiration was significantly and positively correlated with β-glucosidase activity, EEG, SOC, total N, ammonium N and nitrate N contents. The results indicated that high N fertilization improved soil chemical properties, but significantly increased soil respiration.

  10. Seasonal Patterns of Soil Respiration and Related Soil Biochemical Properties under Nitrogen Addition in Winter Wheat Field

    PubMed Central

    Liang, Guopeng; Houssou, Albert A.; Wu, Huijun; Cai, Dianxiong; Wu, Xueping; Gao, Lili; Li, Jing; Wang, Bisheng; Li, Shengping

    2015-01-01

    Understanding the changes of soil respiration under increasing N fertilizer in cropland ecosystems is crucial to accurately predicting global warming. This study explored seasonal variations of soil respiration and its controlling biochemical properties under a gradient of Nitrogen addition during two consecutive winter wheat growing seasons (2013–2015). N was applied at four different levels: 0, 120, 180 and 240 kg N ha-1 year-1 (denoted as N0, N12, N18 and N24, respectively). Soil respiration exhibited significant seasonal variation and was significantly affected by soil temperature with Q10 ranging from 2.04 to 2.46 and from 1.49 to 1.53 during 2013–2014 and 2014–2015 winter wheat growing season, respectively. Soil moisture had no significant effect on soil respiration during 2013–2014 winter wheat growing season but showed a significant and negative correlation with soil respiration during 2014–2015 winter wheat growing season. Soil respiration under N24 treatment was significantly higher than N0 treatment. Averaged over the two growing seasons, N12, N18 and N24 significantly increased soil respiration by 13.4, 16.4 and 25.4% compared with N0, respectively. N addition also significantly increased easily extractable glomalin-related soil protein (EEG), soil organic carbon (SOC), total N, ammonium N and nitrate N contents. In addition, soil respiration was significantly and positively correlated with β-glucosidase activity, EEG, SOC, total N, ammonium N and nitrate N contents. The results indicated that high N fertilization improved soil chemical properties, but significantly increased soil respiration. PMID:26629695

  11. Intrasite sampling of Hong Kong soils contaminated by Caesium-137.

    PubMed

    Ruse, M E; Peart, M R

    2000-07-01

    Previous measurements of soil contamination by Caesium-137 (137Cs) in Hong Kong have been used both to estimate background levels prior to the construction of the Guangdong Nuclear Power Station (GNPS) at Daya Bay and to evaluate health hazards arising from the radionuclide. These measurements are reviewed and contrasted with recent advances in understanding of 137Cs distribution in soil. Preliminary research findings are used to illustrate the microscale variability of 137Cs in the Hong Kong environment and to suggest intrasite sampling methods for establishing suitable reference values.

  12. Mercury Source Zone Identification using Soil Vapor Sampling and Analysis

    SciTech Connect

    Watson, David B; Miller, Carrie L; Lester, Brian P; Lowe, Kenneth Alan; Southworth, George R; Bogle, Mary Anna; Liang, Liyuan; Pierce, Eric M

    2014-01-01

    Development and demonstration of reliable measurement techniqes that can detect and help quantify the nature and extent of elemental mercury (Hg(0)) in the subsurface are needed to reduce certainties in the decision making process and increase the effectiveness of remedial actions. We conducted field tests at the Y-12 National Security Complex (NSC) in Oak Ridge, TN, to determine if sampling and analysis of Hg(0) vapors in the shallow subsurface (<0.3 m depth) can be used to as an indicator of the location and extent of Hg(0) releases in the subsurface. We constructed a rigid PVC pushprobe assembly, which was driven into the ground. Soil gas samples were collected through a sealed inner tube of the assembly and analyzed immediately in the field with a Lumex and/or Jerome Hg(0) analyzer. Time-series sampling showed that Hg vapor concentrations were fairly stable over time suggesting that the vapor phase Hg(0) was not being depleted and that sampling results were not dependent on the soil gas purge volume. Hg(0) vapor data collected at over 200 pushprobe locations at 3 different release sites correlated well to areas of known Hg(0) contamination. Vertical profiling of Hg(0) vapor concentrations conducted at 2 locations provided information on the vertical distribution of Hg(0) contamination in the subsurface. We concluded from our studies that soil gas sampling and analysis can be conducted rapidly and inexpensively at a large scale to help identify areas contaminated with Hg(0).

  13. Sampling and analysis plan for Mount Plant D & D soils packages, Revision 1

    SciTech Connect

    1991-02-01

    There are currently 682 containers of soils in storage at Mound Plant, generated between April 1 and October 31, 1990 as a result of excavation of soils containing plutonium-238 at two ongoing Decontamination and Decommissioning (D&D) Program sites. These areas are known as Area 14, the waste transfer system (WTS) hillside, and Area 17, the Special Metallurgical (SM) Building area. The soils from these areas are part of Mound Plant waste stream number AMDM-000000010, Contaminated Soil, and are proposed for shipment to the Nevada Test Site (NTS) for disposal as low-level radioactive waste. The sealed waste packages, constructed of either wood or metal, are currently being stored in Building 31 and at other locations throughout the Mound facility. At a meeting in Las Vegas, Nevada on October, 26, 1990, DOE Nevada Operations Office (DOE-NV) and NTS representatives requested that the Mound Plant D&D soils proposed for shipment to NTS be sampled for Toxicity Characteristic Leaching Procedure (TCLP) constituents. On December 14, 1990, DOE-NV also requested that additional analyses be performed on the soils from one of the soils boxes for polychlorinated biphenyls (PCBs), particle size distribution, and free liquids. The purpose of this plan is to document the proposed sampling and analyses of the packages of D&D soils produced prior to October 31, 1990. In order to provide a thorough description of the soils excavated from the WTS and SM areas, sections 1.1 and 1.2 provide historical Information concerning the D&D soils, including waste stream evaluations and past sampling data.

  14. 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

  15. The use of Vacutainer tubes for collection of soil samples for helium analysis

    USGS Publications Warehouse

    Hinkle, Margaret E.; Kilburn, James E.

    1979-01-01

    Measurements of the helium concentration of soil samples collected and stored in Vacutainer-brand evacuated glass tubes show that Vacutainers are reliable containers for soil collection. Within the limits of reproducibility, helium content of soils appears to be independent of variations in soil temperature, barometric pressure, and quantity of soil moisture present in the sample.

  16. Effects of substrate addition on soil respiratory carbon release under long-term warming and clipping in a tallgrass prairie.

    PubMed

    Jia, Xiaohong; Zhou, Xuhui; Luo, Yiqi; Xue, Kai; Xue, Xian; Xu, Xia; Yang, Yuanhe; Wu, Liyou; Zhou, Jizhong

    2014-01-01

    Regulatory mechanisms of soil respiratory carbon (C) release induced by substrates (i.e., plant derived substrates) are critical for predicting ecosystem responses to climate change, but the mechanisms are not well understood. In this study, we sampled soils from a long-term field manipulative experiment and conducted a laboratory incubation to explore the role of substrate supply in regulating the differences in soil C release among the experimental treatments, including control, warming, clipping, and warming plus clipping. Three types of substrates (glucose, C3 and C4 plant materials) were added with an amount equal to 1% of soil dry weight under the four treatments. We found that the addition of all three substrates significantly stimulated soil respiratory C release in all four warming and clipping treatments. In soils without substrate addition, warming significantly stimulated soil C release but clipping decreased it. However, additions of glucose and C3 plant materials (C3 addition) offset the warming effects, whereas C4 addition still showed the warming-induced stimulation of soil C release. Our results suggest that long-term warming may inhibit microbial capacity for decomposition of C3 litter but may enhance it for decomposition of C4 litter. Such warming-induced adaptation of microbial communities may weaken the positive C-cycle feedback to warming due to increased proportion of C4 species in plant community and decreased litter quality. In contrast, clipping may weaken microbial capacity for warming-induced decomposition of C4 litter but may enhance it for C3 litter. Warming- and clipping-induced shifts in microbial metabolic capacity may be strongly associated with changes in plant species composition and could substantially influence soil C dynamics in response to global change. PMID:25490701

  17. Effects of substrate addition on soil respiratory carbon release under long-term warming and clipping in a tallgrass prairie.

    PubMed

    Jia, Xiaohong; Zhou, Xuhui; Luo, Yiqi; Xue, Kai; Xue, Xian; Xu, Xia; Yang, Yuanhe; Wu, Liyou; Zhou, Jizhong

    2014-01-01

    Regulatory mechanisms of soil respiratory carbon (C) release induced by substrates (i.e., plant derived substrates) are critical for predicting ecosystem responses to climate change, but the mechanisms are not well understood. In this study, we sampled soils from a long-term field manipulative experiment and conducted a laboratory incubation to explore the role of substrate supply in regulating the differences in soil C release among the experimental treatments, including control, warming, clipping, and warming plus clipping. Three types of substrates (glucose, C3 and C4 plant materials) were added with an amount equal to 1% of soil dry weight under the four treatments. We found that the addition of all three substrates significantly stimulated soil respiratory C release in all four warming and clipping treatments. In soils without substrate addition, warming significantly stimulated soil C release but clipping decreased it. However, additions of glucose and C3 plant materials (C3 addition) offset the warming effects, whereas C4 addition still showed the warming-induced stimulation of soil C release. Our results suggest that long-term warming may inhibit microbial capacity for decomposition of C3 litter but may enhance it for decomposition of C4 litter. Such warming-induced adaptation of microbial communities may weaken the positive C-cycle feedback to warming due to increased proportion of C4 species in plant community and decreased litter quality. In contrast, clipping may weaken microbial capacity for warming-induced decomposition of C4 litter but may enhance it for C3 litter. Warming- and clipping-induced shifts in microbial metabolic capacity may be strongly associated with changes in plant species composition and could substantially influence soil C dynamics in response to global change.

  18. Heavy metal accumulation in soils, plants, and hair samples: an assessment of heavy metal exposure risks from the consumption of vegetables grown on soils previously irrigated with wastewater.

    PubMed

    Massaquoi, Lamin Daddy; Ma, Hui; Liu, Xue Hui; Han, Peng Yu; Zuo, Shu-Mei; Hua, Zhong-Xian; Liu, Dian-Wu

    2015-12-01

    It is common knowledge that soils irrigated with wastewater accumulate heavy metals more than those irrigated with cleaner water sources. However, little is known on metal concentrations in soils and cultivars after the cessation of wastewater use. This study assessed the accumulation and health risk of heavy metals 3 years post-wastewater irrigation in soils, vegetables, and farmers' hair. Soils, vegetables, and hair samples were collected from villages previously irrigating with wastewater (experimental villages) and villages with no history of wastewater irrigation (control villages). Soil samples were digested in a mixture of HCL/HNO3/HCLO4/HF. Plants and hair samples were digested in HNO3/HCLO4 mixture. Inductive coupled plasma-optical emission spectrometer (ICP-OES) was used to determine metal concentrations of digested extracts. Study results indicate a persistence of heavy metal concentration in soils and plants from farms previously irrigated with wastewater. In addition, soils previously irrigated with wastewater were severely contaminated with cadmium. Hair metal concentrations of farmers previously irrigating with wastewater were significantly higher (P < 0.05) than farmers irrigating with clean water, but metal concentrations in hair samples of farmers previously irrigating with wastewater were not associated with current soil metal concentrations. The study concludes that there is a persistence of heavy metals in soils and plants previously irrigated with wastewater, but high metal concentrations in hair samples of farmers cannot be associated with current soil metal concentrations.

  19. Uncertainty in sample estimates and the implicit loss function for soil information.

    NASA Astrophysics Data System (ADS)

    Lark, Murray

    2015-04-01

    One significant challenge in the communication of uncertain information is how to enable the sponsors of sampling exercises to make a rational choice of sample size. One way to do this is to compute the value of additional information given the loss function for errors. The loss function expresses the costs that result from decisions made using erroneous information. In certain circumstances, such as remediation of contaminated land prior to development, loss functions can be computed and used to guide rational decision making on the amount of resource to spend on sampling to collect soil information. In many circumstances the loss function cannot be obtained prior to decision making. This may be the case when multiple decisions may be based on the soil information and the costs of errors are hard to predict. The implicit loss function is proposed as a tool to aid decision making in these circumstances. Conditional on a logistical model which expresses costs of soil sampling as a function of effort, and statistical information from which the error of estimates can be modelled as a function of effort, the implicit loss function is the loss function which makes a particular decision on effort rational. In this presentation the loss function is defined and computed for a number of arbitrary decisions on sampling effort for a hypothetical soil monitoring problem. This is based on a logistical model of sampling cost parameterized from a recent geochemical survey of soil in Donegal, Ireland and on statistical parameters estimated with the aid of a process model for change in soil organic carbon. It is shown how the implicit loss function might provide a basis for reflection on a particular choice of sample size by comparing it with the values attributed to soil properties and functions. Scope for further research to develop and apply the implicit loss function to help decision making by policy makers and regulators is then discussed.

  20. Effects of sterile storage, cation saturation and substrate additions on the degradability and extractability of nonylphenol and phenanthrene in soil.

    PubMed

    Shchegolikhina, Anastasia; Marschner, Bernd

    2013-11-01

    The main objective of this study was to determine the effects of long-term abiotic processes during aging of organic pollutants in soil on their microbial degradability and formation of non-extractable residues. The specific aims of our study were to investigate how the fate of p353-nonylphenol (NP) and phenanthrene (Phe) in soils might be affected by: (i) saturation of soil by cations with different valency (Na(+), Ca(2+) or Al(3+)), (ii) addition of organic substrate (wood flour) during incubation period and (iii) different soil moisture levels. This study showed positive effect of long-term aging of sterilized samples on respiration of re-inoculated samples. However, the lack of aging effects on the mineralization of NP and Phe indicates that slow sorption processes by diffusion into less bioaccessible domains were not relevant in studied soils. Similarly, the lower respiration and xenobiotic mineralization rates in the Na(+) and Al(3+) treated soils indicate that this is due to toxic effects on microbial activity and not due to xenobiotic accessibility. Instead, the formation of non-extractable residues was strongly promoted by biological activity, most likely through formation of more reactive metabolites. The addition of wood flour greatly stimulated microbial respiration and enhanced NP mineralization while inhibiting that of Phe. Along with negligible effect of water addition after 4 weeks of incubation on kinetics of soil respiration, the soil moisture effect on xenobiotics mineralization indicates that most probably the bioavailability of NP and Phe increased due to bridging role of water films in soil.

  1. DUS II SOIL GAS SAMPLING AND AIR INJECTION TEST RESULTS

    SciTech Connect

    Noonkester, J.; Jackson, D.; Jones, W.; Hyde, W.; Kohn, J.; Walker, R.

    2012-09-20

    Soil vapor extraction (SVE) and air injection well testing was performed at the Dynamic Underground Stripping (DUS) site located near the M-Area Settling Basin (referred to as DUS II in this report). The objective of this testing was to determine the effectiveness of continued operation of these systems. Steam injection ended on September 19, 2009 and since this time the extraction operations have utilized residual heat that is present in the subsurface. The well testing campaign began on June 5, 2012 and was completed on June 25, 2012. Thirty-two (32) SVE wells were purged for 24 hours or longer using the active soil vapor extraction (ASVE) system at the DUS II site. During each test five or more soil gas samples were collected from each well and analyzed for target volatile organic compounds (VOCs). The DUS II site is divided into four parcels (see Figure 1) and soil gas sample results show the majority of residual VOC contamination remains in Parcel 1 with lesser amounts in the other three parcels. Several VOCs, including tetrachloroethylene (PCE) and trichloroethylene (TCE), were detected. PCE was the major VOC with lesser amounts of TCE. Most soil gas concentrations of PCE ranged from 0 to 60 ppmv with one well (VEW-22A) as high as 200 ppmv. Air sparging (AS) generally involves the injection of air into the aquifer through either vertical or horizontal wells. AS is coupled with SVE systems when contaminant recovery is necessary. While traditional air sparging (AS) is not a primary component of the DUS process, following the cessation of steam injection, eight (8) of the sixty-three (63) steam injection wells were used to inject air. These wells were previously used for hydrous pyrolysis oxidation (HPO) as part of the DUS process. Air sparging is different from the HPO operations in that the air was injected at a higher rate (20 to 50 scfm) versus HPO (1 to 2 scfm). . At the DUS II site the air injection wells were tested to determine if air sparging affected

  2. Phase chemistry of Apollo 14 soil sample 14259

    NASA Technical Reports Server (NTRS)

    Aitken, F. K.; Anderson, D. H.; Bass, M. N.; Brown, R. W.; Butler, P., Jr.; Heiken, G.; Jakes, P.; Reid, A. M.; Ridley, W. I.; Takeda, H.

    1974-01-01

    Optical, X-ray-diffraction and electron-microprobe techniques were used to investigate 0.26 gm of Apollo 14 soil sample 14259. Major element microprobe analyses were made of 470 mineral grains and 388 glass grains. The mineral abundances in the soil are 45% plagioclase, 41% pyroxene, 7% olivine, 3% oxides, 2% K-feldspar; 1% nickel-iron, and less than 1% troilite. The glasses have a wide range of compositions but preferred values are evident and are interpreted as representative of rock types contributing to the soil at the Fra Mauro site. Eleven per cent of the glasses have compositions like those of mare basalts or mare soils and are believed to be mare-derived. Eighty-six per cent of the glasses are equivalent in composition to basalts that have higher Al, and lower Ca/Al and Fe/Mg ratios than mare basalts. The most abundant compositional type is named Fra Mauro basaltic glass and is subdivided into three related types. The other major glass type in the soil corresponds in composition to anorthositic gabbro.

  3. Analysis methods for the determination of anthropogenic additions of P to agricultural soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phosphorus additions and measurement in soil is of concern on lands where biosolids have been applied. Colorimetric analysis for plant-available P may be inadequate for the accurate assessment of soil P. Phosphate additions in a regulatory environment need to be accurately assessed as the reported...

  4. Effect of exogenous phosphorus addition on soil respiration in Calamagrostis angustifolia freshwater marshes of Northeast China

    NASA Astrophysics Data System (ADS)

    Song, Changchun; Liu, Deyan; Song, Yanyu; Yang, Guisheng; Wan, Zhongmei; Li, Yingchen; Xu, Xiaofeng

    2011-03-01

    Anthropogenic activities have increased phosphorus (P) inputs to wetland ecosystems. However, little is known about the effect of P enrichment on soil respiration in these ecosystems. To understand the effect of P enrichment on soil respiration, we conducted a field experiment in Calamagrostis angustifolia-dominated freshwater marshes, the Sanjiang Plain, Northeast China. We investigated soil respiration in the first growing season after P addition at four rates (0, 1.2, 4.8 and 9.6 g P m-2 year-1). In addition, we also examined aboveground biomass, soil labile C fractions (dissolved organic C, DOC; microbial biomass C, MBC; easily oxidizable C, EOC) and enzyme activities (invertase, urease and acid phosphatase activities) following one year of P addition. P addition decreased soil respiration during the growing season. Dissolved organic C in soil pore water increased after P addition at both 5 and 15 cm depths. Moreover, increased P input generally inhibited soil MBC and enzyme activities, and had no effects on aboveground biomass and soil EOC. Our results suggest that, in the short-term, soil respiration declines under P enrichment in C. angustifolia-dominated freshwater marshes of Northeast China, and its extent varies with P addition levels.

  5. Practical method for extraction of PCR-quality DNA from environmental soil samples.

    PubMed

    Fitzpatrick, Kelly A; Kersh, Gilbert J; Massung, Robert F

    2010-07-01

    Methods for the extraction of PCR-quality DNA from environmental soil samples by using pairs of commercially available kits were evaluated. Coxiella burnetii DNA was detected in spiked soil samples at <1,000 genome equivalents per gram of soil and in 12 (16.4%) of 73 environmental soil samples.

  6. Adsorption of carbon monoxide by samples of soils and peat-sand mixtures

    NASA Astrophysics Data System (ADS)

    Smagin, A. V.; Sadovnikova, N. B.; Mazanova, V. S.; Dolzhich, A. R.

    2009-11-01

    The adsorption of carbon monoxide (CO) by loose samples of natural soils and artificial organomineral mixtures depending on the water content was studied in laboratory experiments. The highest adsorption of CO was found for the samples of 100% organic soil modifier and its 80% mixture with sand (200 µg of CO/kg per hour and more). The lowest CO adsorption (10-15 µg of CO/kg per hour) was observed for an Arenosol. The addition of 5 wt % of the modifier to the desert sand increased the adsorption of CO to 50-55 µg of CO/kg per hour, as was typical for the chernozem and soddy-podzolic soil. The adsorption of CO as depending on the water content in the samples was a unimodal function, and the adsorption levels corresponded to the optimum soil water content (about 0.4-0.6 of the maximum water capacity). On the basis of the results, the Arid Grow soil modifier was recommended as a highly efficient agent for the regulation of the gas function of soils in urban areas subjected to increased CO emissions from vehicles and industrial enterprises.

  7. Terrestrial exposure of oilfield flowline additives diminish soil structural stability and remediative microbial function.

    PubMed

    George, S J; Sherbone, J; Hinz, C; Tibbett, M

    2011-10-01

    Onshore oil production pipelines are major installations in the petroleum industry, stretching many thousands of kilometres worldwide which also contain flowline additives. The current study focuses on the effect of the flowline additives on soil physico-chemical and biological properties and quantified the impact using resilience and resistance indices. Our findings are the first to highlight deleterious effect of flowline additives by altering some fundamental soil properties, including a complete loss of structural integrity of the impacted soil and a reduced capacity to degrade hydrocarbons mainly due to: (i) phosphonate salts (in scale inhibitor) prevented accumulation of scale in pipelines but also disrupted soil physical structure; (ii) glutaraldehyde (in biocides) which repressed microbial activity in the pipeline and reduced hydrocarbon degradation in soil upon environmental exposure; (iii) the combinatory effects of these two chemicals synergistically caused severe soil structural collapse and disruption of microbial degradation of petroleum hydrocarbons.

  8. Soil microbial community structure and nitrogen cycling responses to agroecosystem management and carbon substrate addition

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

    Fertilizer application in conventional agriculture leads to N saturation and decoupled soil C and N cycling, whereas organic practices, e.g. complex rotations and legume incorporation, often results in increased SOM and tightly coupled cycles of C and N. These legacy effects of management on soils likely affect microbial community composition and microbial process rates. This project tested if agricultural management practices led to distinct microbial communities and if those communities differed in ability to utilize labile plant carbon substrates and to produce more plant available N. We addressed several specific questions in this project. 1) Do organic and conventional management legacies on similar soils produce distinct soil bacterial and fungal community structures and abundances? 2) How do these microbial community structures change in response to carbon substrate addition? 3) How do the responses of the microbial communities influence N cycling? To address these questions we conducted a laboratory incubation of organically and conventionally managed soils. We added C-13 labelled glucose either in one large dose or several smaller pulses. We extracted genomic DNA from soils before and after incubation for TRFLP community fingerprinting. We measured C in soil pools and respiration and N in soil extracts and leachates. Management led to different compositions of bacteria and fungi driven by distinct components in organic soils. Biomass did not differ across treatments indicating that differences in cycling were due to composition rather than abundance. C substrate addition led to convergence in bacterial communities; however management still strongly influenced the difference in communities. Fungal communities were very distinct between managements and plots with substrate addition not altering this pattern. Organic soils respired 3 times more of the glucose in the first week than conventional soils (1.1% vs 0.4%). Organic soils produced twice as much

  9. 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.

  10. Soil sample preparation using microwave digestion for uranium analysis

    SciTech Connect

    MOHAGHEGHI,AMIR H.; PRESTON,ROSE; AKBARZADEH,MANSOOR; BAKHTIAR,STEVEN

    2000-04-05

    A new sample preparation procedure has been developed for digestion of soil samples for uranium analysis. The technique employs a microwave oven digestion system to digest the sample and to prepare it for separation chemistry and analysis. The method significantly reduces the volume of acids used, eliminates a large fraction of acid vapor emissions, and speeds up the analysis time. The samples are analyzed by four separate techniques: Gamma Spectrometry, Alpha Spectroscopy using the open digestion method, Kinetic Phosphorescence Analysis (KPA) using open digestion, and KPA by Microwave digestion technique. The results for various analytical methods are compared and used to confirm the validity of the new procedure. The details of the preparation technique along with its benefits are discussed.

  11. [Effects of nitrogen addition on red soil microbes in the Cinnamomum camphora plantation].

    PubMed

    Yu, Pei-Yi; Zhu, Fan; Su, Shao-Feng; Wang, Zhi-Yong; Yan, Wen-De

    2013-08-01

    In order to investigate the effects of nitrogen addition on the red soil microbial communities in Cinnamomum camphora plantation, three treatments of nitrogen addition were designated as control (N0: 0 g x m(-2)), low nitrogen (N1: 5 g x m(-2)) and high nitrogen (N2 :15 g x m(-2)). Soil microbial numbers, microbial biomass carbon (C), biomass N and microbial community functional diversity were analyzed using the methods of plate counting, chloroform fumigation and BIOLOG system, respectively. The results showed that the numbers of bacteria in N1 and N2 were significantly higher than the control 1 month after nitrogen addition, but significantly lower than the control 13 months after nitrogen addition, and the number of fungi and actinomycetes were not significantly changed after nitrogen addition. The soil microbial biomass C, N increased with the increase of nitrogen at 1 month, but the soil microbial biomass C increased significantly 13 months after nitrogen addition when compared with 1 month after nitrogen addition. The soil microbial biomass N was lower 13 months after nitrogen addition when compared with 1 month after nitrogen addition, but the difference was not significant (P > 0.05). The variation of the carbon utilization efficiency of soil microbial communities was resulted from the nitrogen addition. The indices of Shannon index, Simpson index and McIntosh index were calculated to show the differences in nitrogen treatments and in times, which turned out to be insignificant.

  12. Microscope Image of a Martian Soil Surface Sample

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This is the closest view of the material underneath NASA's Phoenix Mars Lander. This sample was taken from the top centimeter of the Martian soil, and this image from the lander's Optical Microscope demonstrates its overall composition.

    The soil is mostly composed of fine orange particles, and also contains larger grains, about a tenth of a millimeter in diameter, and of various colors. The soil is sticky, keeping together as a slab of material on the supporting substrate even though the substrate is tilted to the vertical.

    The fine orange grains are at or below the resolution of the Optical Microscope. Mixed into the soil is a small amount&mdashabout 0.5 percent&mdashof white grains, possibly of a salt. The larger grains range from black to almost transparent in appearance. At the bottom of the image, the shadows of the Atomic Force Microscope (AFM) beams are visible. This image is 1 millimeter x 2 millimeters.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by JPL, Pasadena, Calif. Spacecraft development was by Lockheed Martin Space Systems, Denver.

  13. Characterization of Apollo Bulk Soil Samples Under Simulated Lunar Conditions

    NASA Astrophysics Data System (ADS)

    Donaldson Hanna, K. L.; Pieters, C. M.; Thomas, I.; Bowles, N. E.; Greenhagen, B. T.

    2013-12-01

    Remote observations provide key insights into the composition and evolution of planetary surfaces. A fundamentally important component to any remote compositional analysis of planetary surfaces is laboratory measurements of well-characterized samples measured under the appropriate environmental conditions. The vacuum environment of airless bodies like the Moon creates a steep thermal gradient in the upper hundreds of microns of regolith. Lab studies of particulate rocks and minerals as well as selected lunar soils under vacuum and lunar-like conditions have identified significant effects of this thermal gradient on thermal infrared (TIR) spectral measurements [e.g. Logan et al. 1973, Salisbury and Walter 1989, Thomas et al. 2012, Donaldson Hanna et al. 2012]. Such lab studies demonstrate the high sensitivity of TIR emissivity spectra to environmental conditions under which they are measured. To best understand the effects of the near surface-environment of the Moon, a consortium of four institutions with the capabilities of characterizing lunar samples was created. The goal of the Thermal Infrared Emission Studies of Lunar Surface Compositions Consortium (TIRES-LSCC) is to characterize Apollo bulk soil samples with a range of compositions and maturities in simulated lunar conditions to provide better context for the spectral effects due to varying compositions and soil maturity as well as for the interpretation of data obtained by the LRO Diviner Lunar Radiometer and future lunar and airless body thermal emission spectrometers. An initial set of thermal infrared emissivity measurements of the bulk lunar soil samples will be made in three of the laboratories included in the TIRES-LSCC: the Asteroid and Lunar Environment Chamber (ALEC) in RELAB at Brown University, the Simulated Lunar Environment chamber in the Planetary Spectroscopy Facility (PSF) at the University of Oxford, and the Simulated Airless Body Emission Laboratory (SABEL) at the Jet Propulsion Laboratory

  14. Seasonality, Rather than Nutrient Addition or Vegetation Types, Influenced Short-Term Temperature Sensitivity of Soil Organic Carbon Decomposition

    PubMed Central

    He, Feng-Peng; Wang, Wei

    2016-01-01

    The response of microbial respiration from soil organic carbon (SOC) decomposition to environmental changes plays a key role in predicting future trends of atmospheric CO2 concentration. However, it remains uncertain whether there is a universal trend in the response of microbial respiration to increased temperature and nutrient addition among different vegetation types. In this study, soils were sampled in spring, summer, autumn and winter from five dominant vegetation types, including pine, larch and birch forest, shrubland, and grassland, in the Saihanba area of northern China. Soil samples from each season were incubated at 1, 10, and 20°C for 5 to 7 days. Nitrogen (N; 0.035 mM as NH4NO3) and phosphorus (P; 0.03 mM as P2O5) were added to soil samples, and the responses of soil microbial respiration to increased temperature and nutrient addition were determined. We found a universal trend that soil microbial respiration increased with increased temperature regardless of sampling season or vegetation type. The temperature sensitivity (indicated by Q10, the increase in respiration rate with a 10°C increase in temperature) of microbial respiration was higher in spring and autumn than in summer and winter, irrespective of vegetation type. The Q10 was significantly positively correlated with microbial biomass and the fungal: bacterial ratio. Microbial respiration (or Q10) did not significantly respond to N or P addition. Our results suggest that short-term nutrient input might not change the SOC decomposition rate or its temperature sensitivity, whereas increased temperature might significantly enhance SOC decomposition in spring and autumn, compared with winter and summer. PMID:27070782

  15. Seasonality, Rather than Nutrient Addition or Vegetation Types, Influenced Short-Term Temperature Sensitivity of Soil Organic Carbon Decomposition.

    PubMed

    Qian, Yu-Qi; He, Feng-Peng; Wang, Wei

    2016-01-01

    The response of microbial respiration from soil organic carbon (SOC) decomposition to environmental changes plays a key role in predicting future trends of atmospheric CO2 concentration. However, it remains uncertain whether there is a universal trend in the response of microbial respiration to increased temperature and nutrient addition among different vegetation types. In this study, soils were sampled in spring, summer, autumn and winter from five dominant vegetation types, including pine, larch and birch forest, shrubland, and grassland, in the Saihanba area of northern China. Soil samples from each season were incubated at 1, 10, and 20°C for 5 to 7 days. Nitrogen (N; 0.035 mM as NH4NO3) and phosphorus (P; 0.03 mM as P2O5) were added to soil samples, and the responses of soil microbial respiration to increased temperature and nutrient addition were determined. We found a universal trend that soil microbial respiration increased with increased temperature regardless of sampling season or vegetation type. The temperature sensitivity (indicated by Q10, the increase in respiration rate with a 10°C increase in temperature) of microbial respiration was higher in spring and autumn than in summer and winter, irrespective of vegetation type. The Q10 was significantly positively correlated with microbial biomass and the fungal: bacterial ratio. Microbial respiration (or Q10) did not significantly respond to N or P addition. Our results suggest that short-term nutrient input might not change the SOC decomposition rate or its temperature sensitivity, whereas increased temperature might significantly enhance SOC decomposition in spring and autumn, compared with winter and summer.

  16. Seasonality, Rather than Nutrient Addition or Vegetation Types, Influenced Short-Term Temperature Sensitivity of Soil Organic Carbon Decomposition.

    PubMed

    Qian, Yu-Qi; He, Feng-Peng; Wang, Wei

    2016-01-01

    The response of microbial respiration from soil organic carbon (SOC) decomposition to environmental changes plays a key role in predicting future trends of atmospheric CO2 concentration. However, it remains uncertain whether there is a universal trend in the response of microbial respiration to increased temperature and nutrient addition among different vegetation types. In this study, soils were sampled in spring, summer, autumn and winter from five dominant vegetation types, including pine, larch and birch forest, shrubland, and grassland, in the Saihanba area of northern China. Soil samples from each season were incubated at 1, 10, and 20°C for 5 to 7 days. Nitrogen (N; 0.035 mM as NH4NO3) and phosphorus (P; 0.03 mM as P2O5) were added to soil samples, and the responses of soil microbial respiration to increased temperature and nutrient addition were determined. We found a universal trend that soil microbial respiration increased with increased temperature regardless of sampling season or vegetation type. The temperature sensitivity (indicated by Q10, the increase in respiration rate with a 10°C increase in temperature) of microbial respiration was higher in spring and autumn than in summer and winter, irrespective of vegetation type. The Q10 was significantly positively correlated with microbial biomass and the fungal: bacterial ratio. Microbial respiration (or Q10) did not significantly respond to N or P addition. Our results suggest that short-term nutrient input might not change the SOC decomposition rate or its temperature sensitivity, whereas increased temperature might significantly enhance SOC decomposition in spring and autumn, compared with winter and summer. PMID:27070782

  17. Soil bacterial communities respond to mowing and nutrient addition in a steppe ecosystem.

    PubMed

    Zhang, Ximei; Chen, Quansheng; Han, Xingguo

    2013-01-01

    In many grassland ecosystems, nitrogen (N) and phosphorus (P) are added to improve plant productivity, and the aboveground plant biomass is mowed and stored as hay for the bullamacow. Nutrient addition and mowing affect the biodiversity and ecosystem functioning, and most of the previous studies have primarily focused on their effects on macro-organisms, neglecting the responses of soil microbial communities. In this study, we examined the changes in three community attributes (abundance, richness, and composition) of the entire bacterial kingdom and 16 dominant bacterial phyla/classes in response to mowing, N addition, P addition, and their combinations, by conducting a 5-year experiment in a steppe ecosystem in Inner Mongolia, China. Overall, N addition had a greater effect than mowing and P addition on most of these bacterial groups, as indicated by changes in the abundance, richness and composition in response to these treatments. N addition affected these soil bacterial groups primarily through reducing soil pH and increasing available N content. Meanwhile, the 16 bacterial phyla/classes responded differentially to these experimental treatments, with Acidobacteria, Acidimicrobidae, Deltaproteobacteria, and Gammaproteobacteria being the most sensitive. The changes in the abundance, richness, and composition of various bacterial groups could imply some potential shift in their ecosystem functions. Furthermore, the important role of decreased soil pH caused by N addition in affecting soil bacterial communities suggests the importance of restoring acidified soil to maintain soil bacterial diversity. PMID:24391915

  18. Assessment of sampling strategy for explosives-contaminated soils

    SciTech Connect

    Thiboutot, S.; Ampleman, G.; Jenkins, T.F.; Walsh, M.E.; Thorne, P.G.; Ranney, T.A.; Grant, C.L.

    1997-12-31

    An explosives-contaminated site was characterized using composite sampling, in-field sample homogenization and on-site analysis. Explosives contaminated sites demonstrate large short-range heterogeneity due to the crystalline nature and poor water solubility of the dispersed contaminants. The sampling strategy must be carefully planned in order to minimize sampling error and total uncertainty. The site investigated in this particular study is an anti-tank firing range that has been in-use for over 20 years. The ammunition fired at this range is a melt-cast explosive based on a mixture of HMX and TNT in the ratio of 70:30. Two previous preliminary sampling surveys of this site have shown high levels of HMX in soil samples collected nearby the targeted tanks. This particular site was chosen for a collaborative effort between the Canadian Department of National Defence and the USA Department of Defense to study sampling strategies and sample heterogeneity where HMX is the main contaminant. On-site colorimetric TNT and HMX methods and enzyme immunoassay TNT and RDX methods were used initially to evaluate if the sampling pattern used provided representative results. A 6 m square grid (36 m{sup 2}) pattern was established, including two of the targeted tanks. Seventeen grids were installed and composite samples were collected within those grids. Four surface composite samples were collected in each quadrant of each grid using a circular pattern that sampled about 10% of the top 5 cm of the surface. Replicates were collected to assess the representativeness achieved. Field analysis showed concentrations of HMX ranged from as high as 1640 mg/kg near one target to 2.1 mg/kg at a distance of 15 m from the target. On the other hand, TNT concentrations were much lower than would be expected based on the 70:30 composition ratio. Results from the colorimetric on-site analyses were in excellent agreement with laboratory results.

  19. Process and apparatus for obtaining samples of liquid and gas from soil

    DOEpatents

    Rossabi, Joseph; May, Christopher P.; Pemberton, Bradley E.; Shinn, Jim; Sprague, Keith

    1999-01-01

    An apparatus and process for obtaining samples of liquid and gas from subsurface soil is provided having filter zone adjacent an external expander ring. The expander ring creates a void within the soil substrate which encourages the accumulation of soil-borne fluids. The fluids migrate along a pressure gradient through a plurality of filters before entering a first chamber. A one-way valve regulates the flow of fluid into a second chamber in further communication with a collection tube through which samples are collected at the surface. A second one-way valve having a reverse flow provides additional communication between the chambers for the pressurized cleaning and back-flushing of the apparatus.

  20. Process and apparatus for obtaining samples of liquid and gas from soil

    DOEpatents

    Rossabi, J.; May, C.P.; Pemberton, B.E.; Shinn, J.; Sprague, K.

    1999-03-30

    An apparatus and process for obtaining samples of liquid and gas from subsurface soil is provided having filter zone adjacent an external expander ring. The expander ring creates a void within the soil substrate which encourages the accumulation of soil-borne fluids. The fluids migrate along a pressure gradient through a plurality of filters before entering a first chamber. A one-way valve regulates the flow of fluid into a second chamber in further communication with a collection tube through which samples are collected at the surface. A second one-way valve having a reverse flow provides additional communication between the chambers for the pressurized cleaning and back-flushing of the apparatus. 8 figs.

  1. Identification of oxidized TNT metabolites in soil samples of a former ammunition plant.

    PubMed

    Bruns-Nagel, D; Schmidt, T C; Drzyzga, O; von Löw, E; Steinbach, K

    1999-01-01

    Water extracts of soil samples of the former ammunition plant "Tanne" near Clausthal-Zellerfeld, Lower Saxony, Germany, were investigated for highly polar oxidized 2,4,6-trinitrotoluene (TNT) metabolites. 0.4 to 9.0 mg/kg dry soil 2,4,6-trinitrobenzoic acid (TNBA) and 5.8 to 544 mg/kg dry soil 2-amino-4,6-dinitrobenzoic acid (2-ADNBA) were found. In addition to the oxidized metabolites, TNT, 4- and 2-aminodinitrotoluene (4- and 2-ADNT), and 2,4-dinitrotoluene (2,4-DNT) were extractable with water. Most interestingly, in one sample, 2-ADNBA represented the main contaminant. The origin of the oxidized nitroaromatics is unknown at this time. They might be generated chemically or photochemically. Furthermore, a biological synthesis seems possible.

  2. Soil carbon sequestration in semi-arid soil through the addition of fuel gas desulfurization gypsum (FGDG)

    NASA Astrophysics Data System (ADS)

    Han, Young-Soo; Tokunaga, Tetsu; Oh, Chamteut

    2014-05-01

    This study investigated a new strategy for increasing carbon retention in slightly alkaline soils through addition of fuel gas desulfurization gypsum (FGDG, CaSO4•2H2O). FGDG is moderately soluble and thus the FGDG amendment may be effective to reduce microbial respiration, to accelerate calcite (CaCO3) precipitation, and to promote soil organic carbon (SOC) complexation on mineral surfaces, but rates of these processes need to be understood. The effects of FGDG addition were tested in laboratory soil columns with and without FGDG-amended layers, and in greenhouse soil columns planted with switchgrass, a biofuel crop. The results of laboratory column experiments demonstrated that additions of FGDG promote soil carbon sequestration through suppressing microbial respiration to the extent of ~200 g per m2 soil per m of supplied water, and promoting calcite precipitation at similar rates. The greenhouse experiments showed that the FGDG treatments did not adversely affect biomass yield (~600 g dry biomass/m2/harvest) at the higher irrigation rate (50 cm/year), but substantially reduced recoverable biomass under the more water-limited conditions (irrigation rate = 20 cm/year). The main achievements of this study are (1) the identification of conditions in which inorganic and organic carbon sequestration is practical in semi-arid and arid soils, (2) development of a method for measuring the total carbon balance in unsaturated soil columns, and (3) the quantification of different pathways for soil carbon sequestration in response to FGDG amendments. These findings provide information for evaluating land use practices for increased soil carbon sequestration under semi-arid region biofuel crop production.

  3. Additive and synergistic effects on plant growth from polymers and organic matter applied to soil simultaneously

    SciTech Connect

    Wallace, A.; Wallace, G.A.

    1986-05-01

    The effect of applying to soil combinations of organic sources was tested and an anionic polyacrylamide and both singly on emergence and growth of tomato and wheat plants. The interactions were generally additive and synergistic. The organic sources and polyacrylamide often had a sparing effect on the need for the other. In one test with an organic source high in N (6%), there was a negative interaction on growth of tomato plants between the polyacrylamide and the organic source. In a test in which the polyacrylamide was applied to soil in solution with a high application of composted manure, the interaction on growth of tomato seedlings was additive. Maximum response for tomatoes for soils low in soil organic matter to polyacrylamide was obtained for low 224 kg ha/sup -1/) rather than high (448 and 1120 kg ha/sup -1/) application levels with or without addition of other organics. Interaction between polyacrylamide and organics on plant growth varied with soil characteristics.

  4. Livermore Big Trees Park 1998 soil sampling plan

    SciTech Connect

    Bainer, R. W.

    1998-10-01

    This sampling plan sets out the sampling goals, rationale, locations, and procedures for a plan to determine the extent of plutonium in soil above background levels in Big Trees Park and identify any possible pathways by which plutonium may have reached the park. The public is invited to witness the sampling at Big Trees Park. The plan has been developed by the U.S. Department of Energy (DOE) and Lawrence Livermore National Laboratory (LLNL) scientists with guidance from the Environmental Protection Agency (EPA), the Radiologic Health and Environmental Health Investigations Branches of the California Health Services Department (CDHS-RHB and CDHS-EHIB), and the Agency for Toxic Substances and Disease Registry (ATSDR). Input from citizens and community organizations was also received during an over-70-day public comment period.

  5. Evaluation of Virus and Microbial Purification in Wastewater Soil Absorption Systems Using Multicomponent Surrogate and Tracer Addition

    NASA Astrophysics Data System (ADS)

    Van Cuyk, S.; Siegrist, R. L.

    2001-05-01

    Wastewater soil absorption systems (WSAS) have the potential to achieve high treatment efficiencies, yet the understanding and predictability of performance with respect to removal of viruses and other pathogens remains limited. As part of a long-term program of research to elucidate the fundamental relationships between performance and WSAS process designs and environmental conditions, research has been completed to evaluate virus and microbial purification using multicomponent surrogate and tracer addition. The primary goal of this research was to quantify the removal of virus and bacteria in land-based treatment systems through the use of microbial surrogates and conservative tracers during controlled experiments with 3-D lysimeters in the laboratory and testing of mature WSAS under field conditions. The surrogates and tracers employed to date have included two viruses (MS-2 and PRD-1 bacteriophages), one bacterium (ice-nucleating active (INA) Pseudomonas) and one conservative tracer (bromide). In addition, efforts have been made to determine the relationship between virus and fecal coliforms in soil samples below a WSAS, and the correlation between E.coli concentrations measured in the percolating soil solution as compared to those estimated from analysis of soil solids samples. The results of the research completed to date have revealed that episodic breakthrough of virus and bacteria does occur in WSAS, particularly during early operation, but that a 3-log removal of virus and near complete removal of fecal coliform bacteria can reasonably be expected in WSAS with 60 to 90 cm of sandy medium. Additionally, results from the research indicate that fecal coliforms may be indicative of virus in soil media directly beneath WSAS receiving STE and the concentrations of fecal coliforms in percolating soil solution may be conservatively estimated from analysis of soil solids. Further laboratory and field research is continuing.

  6. GY SAMPLING THEORY IN ENVIRONMENTAL STUDIES 1: ASSESSING SOIL SPLITTING PROTOCOLS

    EPA Science Inventory

    Five soil sample splitting methods (riffle splitting, paper cone riffle splitting, fractional shoveling, coning and quartering, and grab sampling) were evaluated with synthetic samples to verify Pierre Gy sampling theory expectations. Individually prepared samples consisting of l...

  7. Green manure addition to soil increases grain zinc concentration in bread wheat.

    PubMed

    Aghili, Forough; Gamper, Hannes A; Eikenberg, Jost; Khoshgoftarmanesh, Amir H; Afyuni, Majid; Schulin, Rainer; Jansa, Jan; Frossard, Emmanuel

    2014-01-01

    Zinc (Zn) deficiency is a major problem for many people living on wheat-based diets. Here, we explored whether addition of green manure of red clover and sunflower to a calcareous soil or inoculating a non-indigenous arbuscular mycorrhizal fungal (AMF) strain may increase grain Zn concentration in bread wheat. For this purpose we performed a multifactorial pot experiment, in which the effects of two green manures (red clover, sunflower), ZnSO4 application, soil γ-irradiation (elimination of naturally occurring AMF), and AMF inoculation were tested. Both green manures were labeled with 65Zn radiotracer to record the Zn recoveries in the aboveground plant biomass. Application of ZnSO4 fertilizer increased grain Zn concentration from 20 to 39 mg Zn kg-1 and sole addition of green manure of sunflower to soil raised grain Zn concentration to 31 mg Zn kg-1. Adding the two together to soil increased grain Zn concentration even further to 54 mg Zn kg-1. Mixing green manure of sunflower to soil mobilized additional 48 µg Zn (kg soil)-1 for transfer to the aboveground plant biomass, compared to the total of 132 µg Zn (kg soil)-1 taken up from plain soil when neither green manure nor ZnSO4 were applied. Green manure amendments to soil also raised the DTPA-extractable Zn in soil. Inoculating a non-indigenous AMF did not increase plant Zn uptake. The study thus showed that organic matter amendments to soil can contribute to a better utilization of naturally stocked soil micronutrients, and thereby reduce any need for major external inputs.

  8. Green manure addition to soil increases grain zinc concentration in bread wheat.

    PubMed

    Aghili, Forough; Gamper, Hannes A; Eikenberg, Jost; Khoshgoftarmanesh, Amir H; Afyuni, Majid; Schulin, Rainer; Jansa, Jan; Frossard, Emmanuel

    2014-01-01

    Zinc (Zn) deficiency is a major problem for many people living on wheat-based diets. Here, we explored whether addition of green manure of red clover and sunflower to a calcareous soil or inoculating a non-indigenous arbuscular mycorrhizal fungal (AMF) strain may increase grain Zn concentration in bread wheat. For this purpose we performed a multifactorial pot experiment, in which the effects of two green manures (red clover, sunflower), ZnSO4 application, soil γ-irradiation (elimination of naturally occurring AMF), and AMF inoculation were tested. Both green manures were labeled with 65Zn radiotracer to record the Zn recoveries in the aboveground plant biomass. Application of ZnSO4 fertilizer increased grain Zn concentration from 20 to 39 mg Zn kg-1 and sole addition of green manure of sunflower to soil raised grain Zn concentration to 31 mg Zn kg-1. Adding the two together to soil increased grain Zn concentration even further to 54 mg Zn kg-1. Mixing green manure of sunflower to soil mobilized additional 48 µg Zn (kg soil)-1 for transfer to the aboveground plant biomass, compared to the total of 132 µg Zn (kg soil)-1 taken up from plain soil when neither green manure nor ZnSO4 were applied. Green manure amendments to soil also raised the DTPA-extractable Zn in soil. Inoculating a non-indigenous AMF did not increase plant Zn uptake. The study thus showed that organic matter amendments to soil can contribute to a better utilization of naturally stocked soil micronutrients, and thereby reduce any need for major external inputs. PMID:24999738

  9. Measurement of natural radioactivity from soil samples of Sind, Pakistan.

    PubMed

    Mujahid, S A; Hussain, S

    2011-06-01

    Natural radioactivity has been measured from the soil samples collected from the Sind province of Pakistan. The measured activities of ²²⁶Ra, ²³²Th and ⁴⁰K were found in the range of 18-47, 24-69 and 254-769 Bq kg⁻¹, respectively. The calculated values of the absorbed dose rate in air and the annual effective dose were in the range of 33-87 nGy h⁻¹ and 0.16-0.43 mSv, respectively. The measured results of activity were found compatible with the worldwide findings.

  10. Spectroscopic Evidence for Covalent Binding of Sulfadiazine to Natural Soils via 1,4-nucleophilic addition (Michael Type Addition) studied by Spin Labeling ESR

    NASA Astrophysics Data System (ADS)

    Aleksandrova, Olga

    2015-04-01

    with different polarity. As shown by the spin labeling ESR experiment, molecules modeling SDZ were promptly bound to non-hydrolysable network of soil organic matter only via the aromatic amines that was accompanied by a prompt enlargement of humic particles binding aromatic amines, whereas binding of decomposition products of SDZ to humic acids of soil via the aliphatic amines was not observable. The ESR spectra obviously showed a single-phase process of covalent binding of the aromatic amines. Repeated washouts of labeled soil samples using distil water and ultrafiltration through the membrane of 5000 MWCO PES confirmed irreversible binding of the aromatic amines, and showed that via the aliphatic amines, binding of SDZ or decomposition products of SDZ to soil might also occur but reversibly and only to small soil molecules, which don't enter into the composition of non-hydrolysable part of soil organic matter. SL ESR experiments of different soils at the presence of Laccase highlighted that covalent binding of the aromatic amines to humic particles occurred in the specific hydrophobic areas of soil found as depleted in oxygen. All measured data evidenced that first, SDZ might be decomposed that allowed for measuring the same change of a paramagnetic signal of soil organic matter influenced by both aromatic and aliphatic amines as in the experiment of the interaction of soil with SDZ. Second, a decomposition product of SDZ with the aromatic amine might be bound to non-hydrolysable parts of soil organic matter under specific anaerobic conditions only via 1,4 - nucleophilic addition, Michael-type addition. Gulkowska, A., Thalmann, B., D., Hollender, J., & Krauss, M. (2014). Chemosphere, 107, 366 - 372. Müller, T., Rosendahl, I., Focks, A., Siemens, J., Klasmeier, J., & Matthies. (2013). Environmental Pollution, 172,180 - 185. Nowak, K.M., Miltner, A., Gehre, M., Schaeffer, A., & Kaestner, M. (2011). Environmental Science & Technology 45, 999 - 1006. Weber, E.J., Spidle

  11. Spectroscopic Evidence for Covalent Binding of Sulfadiazine to Natural Soils via 1,4-nucleophilic addition (Michael Type Addition) studied by Spin Labeling ESR

    NASA Astrophysics Data System (ADS)

    Aleksandrova, Olga

    2015-04-01

    with different polarity. As shown by the spin labeling ESR experiment, molecules modeling SDZ were promptly bound to non-hydrolysable network of soil organic matter only via the aromatic amines that was accompanied by a prompt enlargement of humic particles binding aromatic amines, whereas binding of decomposition products of SDZ to humic acids of soil via the aliphatic amines was not observable. The ESR spectra obviously showed a single-phase process of covalent binding of the aromatic amines. Repeated washouts of labeled soil samples using distil water and ultrafiltration through the membrane of 5000 MWCO PES confirmed irreversible binding of the aromatic amines, and showed that via the aliphatic amines, binding of SDZ or decomposition products of SDZ to soil might also occur but reversibly and only to small soil molecules, which don't enter into the composition of non-hydrolysable part of soil organic matter. SL ESR experiments of different soils at the presence of Laccase highlighted that covalent binding of the aromatic amines to humic particles occurred in the specific hydrophobic areas of soil found as depleted in oxygen. All measured data evidenced that first, SDZ might be decomposed that allowed for measuring the same change of a paramagnetic signal of soil organic matter influenced by both aromatic and aliphatic amines as in the experiment of the interaction of soil with SDZ. Second, a decomposition product of SDZ with the aromatic amine might be bound to non-hydrolysable parts of soil organic matter under specific anaerobic conditions only via 1,4 - nucleophilic addition, Michael-type addition. Gulkowska, A., Thalmann, B., D., Hollender, J., & Krauss, M. (2014). Chemosphere, 107, 366 - 372. Müller, T., Rosendahl, I., Focks, A., Siemens, J., Klasmeier, J., & Matthies. (2013). Environmental Pollution, 172,180 - 185. Nowak, K.M., Miltner, A., Gehre, M., Schaeffer, A., & Kaestner, M. (2011). Environmental Science & Technology 45, 999 - 1006. Weber, E.J., Spidle

  12. Influences of biochar addition on vegetable soil nitrogen balance and pH buffering capacity

    NASA Astrophysics Data System (ADS)

    Yu, Y.; Odindo, AO; Xue, L.; Yang, L.

    2016-08-01

    Leaching is a major path for chemical nitrogen fertilizer loss from in vegetable soil, which would destroy soil pH buffering capacity soil and result in acidification. It has been a common phenomenon in Tai Lake Region, China. However, few study focused on the change soil pH buffering capacity, especially the effect of soil amendment on pH buffering capacity. In this study, a pot experiment was conducted to research the effects of biochar addition to a vegetable soil on nitrogen leaching and pH buffering capacity with pakchoi (B.chinensis L.) growth as the experimental crop. The results showed that biochar could significantly increase the pakchoi nitrogen utilization efficiency, decrease 48%-65% nitrogen loss from leaching under the urea continuous applied condition. Biochar also could effectively maintain the content of soil organic matter and base cations. Therefore, it rose up soil pH buffering capacity by 9.4%-36.8% and significantly slowed down acidification rate. It was suggested that 1%-2% addition ratio was recommended from this study when used as similar soil condition.

  13. Soil nutrient additions increase invertebrate herbivore abundances, but not herbivory, across three grassland systems.

    PubMed

    La Pierre, Kimberly J; Smith, Melinda D

    2016-02-01

    Resource availability may influence invertebrate communities, with important consequences for ecosystem function, such as biomass production. We assessed: (1) the effects of experimental soil nutrient additions on invertebrate abundances and feeding rates and (2) the resultant changes in the effects of invertebrates on aboveground plant biomass at three grassland sites spanning the North American Central Plains, across which plant tissue chemistry and biomass vary. Invertebrate communities and rates of herbivory were sampled within a long-term nutrient-addition experiment established at each site along the broad Central Plains precipitation gradient. Additionally, the effects of invertebrates on aboveground plant biomass were determined under ambient and elevated nutrient conditions. At the more mesic sites, invertebrate herbivore abundances increased and their per capita rate of herbivory decreased with nutrient additions. In contrast, at the semi-arid site where plant biomass is low and plant nutrient concentrations are high, invertebrate herbivore abundances did not vary and per capita rates of herbivory increased with nutrient additions. No change in the effect of invertebrate herbivores on aboveground plant biomass was observed at any of the sites. In sum, nutrient additions induced shifts in both plant biomass and leaf nutrient content, which altered invertebrate abundances and feeding rate. However, due to the inverse relationship between changes in herbivore abundance and per capita rates of herbivory, nutrient additions did not alter the effect of invertebrates on aboveground biomass. Overall, we suggest that this inverse response of herbivore abundance and per capita feeding rate may buffer ecosystems against changes in invertebrate damage in response to fluctuations in nutrient levels.

  14. Rain water transport and storage in a model sandy soil with hydrogel particle additives.

    PubMed

    Wei, Y; Durian, D J

    2014-10-01

    We study rain water infiltration and drainage in a dry model sandy soil with superabsorbent hydrogel particle additives by measuring the mass of retained water for non-ponding rainfall using a self-built 3D laboratory set-up. In the pure model sandy soil, the retained water curve measurements indicate that instead of a stable horizontal wetting front that grows downward uniformly, a narrow fingered flow forms under the top layer of water-saturated soil. This rain water channelization phenomenon not only further reduces the available rain water in the plant root zone, but also affects the efficiency of soil additives, such as superabsorbent hydrogel particles. Our studies show that the shape of the retained water curve for a soil packing with hydrogel particle additives strongly depends on the location and the concentration of the hydrogel particles in the model sandy soil. By carefully choosing the particle size and distribution methods, we may use the swollen hydrogel particles to modify the soil pore structure, to clog or extend the water channels in sandy soils, or to build water reservoirs in the plant root zone.

  15. Organic Matter and Water Addition Enhance Soil Respiration in an Arid Region

    PubMed Central

    Lai, Liming; Wang, Jianjian; Tian, Yuan; Zhao, Xuechun; Jiang, Lianhe; Chen, Xi; Gao, Yong; Wang, Shaoming; Zheng, Yuanrun

    2013-01-01

    Climate change is generally predicted to increase net primary production, which could lead to additional C input to soil. In arid central Asia, precipitation has increased and is predicted to increase further. To assess the combined effects of these changes on soil CO2 efflux in arid land, a two factorial manipulation experiment in the shrubland of an arid region in northwest China was conducted. The experiment used a nested design with fresh organic matter and water as the two controlled parameters. It was found that both fresh organic matter and water enhanced soil respiration, and there was a synergistic effect of these two treatments on soil respiration increase. Water addition not only enhanced soil C emission, but also regulated soil C sequestration by fresh organic matter addition. The results indicated that the soil CO2 flux of the shrubland is likely to increase with climate change, and precipitation played a dominant role in regulating soil C balance in the shrubland of an arid region. PMID:24204907

  16. Sampling strategy in molecular microbial ecology: influence of soil sample size on DNA fingerprinting analysis of fungal and bacterial communities.

    PubMed

    Ranjard, Lionel; Lejon, David P H; Mougel, Christophe; Schehrer, Lucie; Merdinoglu, Didier; Chaussod, Rémi

    2003-11-01

    Assessing soil microbial community structure by the use of molecular techniques requires a satisfactory sampling strategy that takes into account the high microbial diversity and the heterogeneous distribution of microorganisms in the soil matrix. The influence of the sample size of three different soil types (sand, silt and clay soils) on the DNA yield and analysis of bacterial and fungal community structure were investigated. Six sample sizes from 0.125 g to 4 g were evaluated. The genetic community structure was assessed by automated ribosomal intergenic spacer analysis (A-RISA fingerprint). Variations between bacterial (B-ARISA) and fungal (F-ARISA) community structure were quantified by using principal component analysis (PCA). DNA yields were positively correlated with the sample size for the sandy and silty soils, suggesting an influence of the sample size on DNA recovery, whereas no correlation was observed in the clay soil. B-ARISA was shown to be consistent between the different sample sizes for each soil type indicating that the sampling procedure has no influence on the assessment of bacterial community structure. On the contrary for F-ARISA profiles, strong variations were observed between replicates of the smaller samples (<1 g). Principal component analysis analysis revealed that sampling aliquots of soil > or =1 g are required to obtain robust and reproducible fingerprinting analysis of the genetic structure of fungal communities. However, the smallest samples could be adequate for the detection of minor populations masked by dominant ones in larger samples. The sampling strategy should therefore be different according to the objectives: rather large soil samples (> or =1 g) for a global description of the genetic community structure, or a large number of small soil samples for a more complete inventory of microbial diversity.

  17. Soil carbon sequestration in prairie grasslands increased by chronic nitrogen addition.

    PubMed

    Fornara, Dario A; Tilman, David

    2012-09-01

    Human-induced increases in nitrogen (N) deposition are common across many terrestrial ecosystems worldwide. Greater N availability not only reduces biological diversity, but also affects the biogeochemical coupling of carbon (C) and N cycles in soil ecosystems. Soils are the largest active terrestrial C pool and N deposition effects on soil C sequestration or release could have global importance. Here, we show that 27 years of chronic N additions to prairie grasslands increased C sequestration in mineral soils and that a potential mechanism responsible for this C accrual was an N-induced increase in root mass. Greater soil C sequestration followed a dramatic shift in plant community composition from native-species-rich C4 grasslands to naturalized-species-rich C3 grasslands, which, despite lower soil C gains per unit of N added, still acted as soil C sinks. Since both high plant diversity and elevated N deposition may increase soil C sequestration, but N deposition also decreases plant diversity, more research is needed to address the long-term implications for soil C storage of these two factors. Finally, because exotic C3 grasses often come to dominate N-enriched grasslands, it is important to determine if such N-dependent soil C sequestration occurs across C3 grasslands in other regions worldwide.

  18. 76 FR 11334 - Safety Zone; Soil Sampling; Chicago River, Chicago, IL

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-02

    ... SECURITY Coast Guard 33 CFR part 165 RIN 1625-AA00 Safety Zone; Soil Sampling; Chicago River, Chicago, IL... to restrict vessels from a portion of the North Branch of the Chicago River due to soil sampling in... the hazards ] associated with the soil sampling efforts. DATES: This rule is effective from 7 a.m....

  19. Nitrogen Addition Altered the Effect of Belowground C Allocation on Soil Respiration in a Subtropical Forest

    PubMed Central

    He, Tongxin; Wang, Qingkui; Wang, Silong; Zhang, Fangyue

    2016-01-01

    The availabilities of carbon (C) and nitrogen (N) in soil play an important role in soil carbon dioxide (CO2) emission. However, the variation in the soil respiration (Rs) and response of microbial community to the combined changes in belowground C and N inputs in forest ecosystems are not yet fully understood. Stem girdling and N addition were performed in this study to evaluate the effects of C supply and N availability on Rs and soil microbial community in a subtropical forest. The trees were girdled on 1 July 2012. Rs was monitored from July 2012 to November 2013, and soil microbial community composition was also examined by phospholipid fatty acids (PLFAs) 1 year after girdling. Results showed that Rs decreased by 40.5% with girdling alone, but N addition only did not change Rs. Interestingly, Rs decreased by 62.7% under the girdling with N addition treatment. The reducing effect of girdling and N addition on Rs differed between dormant and growing seasons. Girdling alone reduced Rs by 33.9% in the dormant season and 54.8% in the growing season compared with the control. By contrast, girdling with N addition decreased Rs by 59.5% in the dormant season and 65.4% in the growing season. Girdling and N addition significantly decreased the total and bacterial PLFAs. Moreover, the effect of N addition was greater than girdling. Both girdling and N addition treatments separated the microbial groups on the basis of the first principal component through principal component analysis compared with control. This indicated that girdling and N addition changed the soil microbial community composition. However, the effect of girdling with N addition treatment separated the microbial groups on the basis of the second principal component compared to N addition treatment, which suggested N addition altered the effect of girdling on soil microbial community composition. These results suggest that the increase in soil N availability by N deposition alters the effect of

  20. Collecting cometary soil samples? Development of the ROSETTA sample acquisition system

    NASA Technical Reports Server (NTRS)

    Coste, P. A.; Fenzi, M.; Eiden, Michael

    1993-01-01

    In the reference scenario of the ROSETTA CNRS mission, the Sample Acquisition System is mounted on the Comet Lander. Its tasks are to acquire three kinds of cometary samples and to transfer them to the Earth Return Capsule. Operations are to be performed in vacuum and microgravity, on a probably rough and dusty surface, in a largely unknown material, at temperatures in the order of 100 K. The concept and operation of the Sample Acquisition System are presented. The design of the prototype corer and surface sampling tool, and of the equipment for testing them at cryogenic temperatures in ambient conditions and in vacuum in various materials representing cometary soil, are described. Results of recent preliminary tests performed in low temperature thermal vacuum in a cometary analog ice-dust mixture are provided.

  1. Comparison of soil solution sampling techniques to assess metal fluxes from contaminated soil to groundwater.

    PubMed

    Coutelot, F; Sappin-Didier, V; Keller, C; Atteia, O

    2014-12-01

    The unsaturated zone plays a major role in elemental fluxes in terrestrial ecosystems. A representative chemical analysis of soil pore water is required for the interpretation of soil chemical phenomena and particularly to assess Trace Elements (TEs) mobility. This requires an optimal sampling system to avoid modification of the extracted soil water chemistry and allow for an accurate estimation of solute fluxes. In this paper, the chemical composition of soil solutions sampled by Rhizon® samplers connected to a standard syringe was compared to two other types of suction probes (Rhizon® + vacuum tube and Rhizon® + diverted flow system). We investigated the effects of different vacuum application procedures on concentrations of spiked elements (Cr, As, Zn) mixed as powder into the first 20 cm of 100-cm columns and non-spiked elements (Ca, Na, Mg) concentrations in two types of columns (SiO2 sand and a mixture of kaolinite + SiO2 sand substrates). Rhizon® was installed at different depths. The metals concentrations showed that (i) in sand, peak concentrations cannot be correctly sampled, thus the flux cannot be estimated, and the errors can easily reach a factor 2; (ii) in sand + clay columns, peak concentrations were larger, indicating that they could be sampled but, due to sorption on clay, it was not possible to compare fluxes at different depths. The different samplers tested were not able to reflect the elemental flux to groundwater and, although the Rhizon® + syringe device was more accurate, the best solution remains to be the use of a lysimeter, whose bottom is kept continuously at a suction close to the one existing in the soil. PMID:25277861

  2. Comparison of soil solution sampling techniques to assess metal fluxes from contaminated soil to groundwater.

    PubMed

    Coutelot, F; Sappin-Didier, V; Keller, C; Atteia, O

    2014-12-01

    The unsaturated zone plays a major role in elemental fluxes in terrestrial ecosystems. A representative chemical analysis of soil pore water is required for the interpretation of soil chemical phenomena and particularly to assess Trace Elements (TEs) mobility. This requires an optimal sampling system to avoid modification of the extracted soil water chemistry and allow for an accurate estimation of solute fluxes. In this paper, the chemical composition of soil solutions sampled by Rhizon® samplers connected to a standard syringe was compared to two other types of suction probes (Rhizon® + vacuum tube and Rhizon® + diverted flow system). We investigated the effects of different vacuum application procedures on concentrations of spiked elements (Cr, As, Zn) mixed as powder into the first 20 cm of 100-cm columns and non-spiked elements (Ca, Na, Mg) concentrations in two types of columns (SiO2 sand and a mixture of kaolinite + SiO2 sand substrates). Rhizon® was installed at different depths. The metals concentrations showed that (i) in sand, peak concentrations cannot be correctly sampled, thus the flux cannot be estimated, and the errors can easily reach a factor 2; (ii) in sand + clay columns, peak concentrations were larger, indicating that they could be sampled but, due to sorption on clay, it was not possible to compare fluxes at different depths. The different samplers tested were not able to reflect the elemental flux to groundwater and, although the Rhizon® + syringe device was more accurate, the best solution remains to be the use of a lysimeter, whose bottom is kept continuously at a suction close to the one existing in the soil.

  3. Multiple nitrogen components in lunar soil sample 12023

    NASA Technical Reports Server (NTRS)

    Brilliant, D. R.; Franchi, I. A.; Pillinger, C. T.

    1993-01-01

    Nitrogen is one of the enigmatic elements in lunar soils and breccias. The large range in (delta)N-15 values found within lunar soils was initially attributed to a secular increase in the N-15/N-14 ratio of 50 percent within the solar corona, and hence in the implanted nitrogen within the lunar regolith. However, more recent explanations have proposed a two (or many) component mixing model of solar wind nitrogen with some hypothetical non-solar components. Such components could include indigenous lunar nitrogen, nitrogen contained in interstellar grains in primitive meteorites, and magnetospheric nitrogen from the terrestrial atmosphere. To understand the makeup of multi-component mixtures it is advantageous to have carbon and noble gas data measured simultaneously, particularly in the case of lunar soils, where the solar wind is a likely fundamental contributor of nitrogen. To this end, a new nitrogen instrument was adapted to give some of the desired data in parallel. Conjoint measurements of N abundance and (delta)N-15 together with N/Ar-36 and Ar-36/Ar-38 ratios obtained during a stepped combustion of lunar soil 12023. The results are preliminary to a much more comprehensive investigation of well characterized fractions of the sample which we still have available from a previous study. Stepped combustion of a sample of 12023,7 yielded 94 ppm nitrogen with a (delta)N-15 = +22.2 percent, as well as the characteristic heavy-light-heavy pattern observed for lunar samples. The low temperature maximum was +75.1 percent at 550 C, the minimum at 800 C with (delta)N-15 = -16.7 percent and the high temperature (delta)N-15 peak is +90.6 percent at 1250 C. The major releases of nitrogen occurred between 650 C - 800 C in the form of a double peak; a third, substantial release occurred at 1150 C yielding 14.2 ppm of nitrogen coinciding with a small but recognizable drop in (delta)N-15 against a regularly increasing trend.

  4. 49 CFR 199.111 - Retention of samples and additional testing.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Retention of samples and additional testing. 199... SAFETY DRUG AND ALCOHOL TESTING Drug Testing § 199.111 Retention of samples and additional testing. (a... period, the employee or the employee's representative, the operator, the Administrator, or, if...

  5. Passive and active soil gas sampling at the Mixed Waste Landfill, Technical Area III, Sandia National Laboratories/New Mexico

    SciTech Connect

    McVey, M.D.; Goering, T.J.; Peace, J.L.

    1996-02-01

    The Environmental Restoration Project at Sandia National Laboratories, New Mexico is tasked with assessing and remediating the Mixed Waste Landfill in Technical Area III. The Mixed Waste Landfill is a 2.6 acre, inactive radioactive and mixed waste disposal site. In 1993 and 1994, an extensive passive and active soil gas sampling program was undertaken to identify and quantify volatile organic compounds in the subsurface at the landfill. Passive soil gas surveys identified levels of PCE, TCE, 1,1, 1-TCA, toluene, 1,1,2-trichlorotrifluoroethane, dichloroethyne, and acetone above background. Verification by active soil gas sampling confirmed concentrations of PCE, TCE, 1,1,1-TCA, and 1,1,2-trichloro-1,2,2-trifluoroethane at depths of 10 and 30 feet below ground surface. In addition, dichlorodifluoroethane and trichlorofluoromethane were detected during active soil gas sampling. All of the volatile organic compounds detected during the active soil gas survey were present in the low ppb range.

  6. Soil Samplers: New Techniques for Subsurface Sampling for Volatile Organic Compounds

    SciTech Connect

    Susan Sorini; John Schabron; Joseph Rovani; Mark Sanderson

    2009-03-31

    Soil sampling techniques for volatile organic analysis must be designed to minimize loss of volatile organic compounds (VOCs) from the soil that is being sampled. Preventing VOC loss from soil cores that are collected from the subsurface and brought to the surface for subsampling is often difficult. Subsurface bulk sample retrieval systems are designed to obtain intact cylindrical cores of soil ranging anywhere from one to four inches in diameter, and one to several feet in length. The current technique that is used to subsample these soil cores for VOC analysis is to expose a horizontal section of the soil core to the atmosphere; screen the exposed soil using a photoionization detector (PID) or other appropriate device to locate contamination in the soil core; and use a hand-operated coring tool to collect samples from the exposed soil for analysis. Because the soil core can be exposed to the atmosphere for a considerable length of time during screening and sample collection, the current sub-sampling technique provides opportunity for VOCs to be lost from the soil. This report describes three alternative techniques from the current technique for screening and collecting soil samples from subsurface soil cores for VOC analysis and field testing that has been done to evaluate the techniques. Based on the results of the field testing, ASTM D4547, Standard Guide for Sampling Waste and Soils for Volatile Organic Compounds, was revised to include information about the new techniques.

  7. 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).

  8. Stimulation of hybrid poplar growth in petroleum-contaminated soils through oxygen addition and soil nutrient amendments.

    PubMed

    Rentz, Jeremy A; Chapman, Brad; Alvarez, Pedro J J; Schnoor, Jerald L

    2003-01-01

    Hybrid poplar trees (Populus deltoides x nigra DN34) were grown in a green-house using hydrocarbon-contaminated soil from a phytoremediation demonstration site in Health, Ohio. Two independent experiments investigated the effect of nutrient addition on poplar growth and the importance of oxygen addition to root development and plant growth. Biomass measurements, poplar height, and leaf color were used as indicators of plant health in the selection of a 10/5/5 NPK fertilizer applied at 1121 kg/ha (112 kg-N, 24.4 kg-P, 46.5 kg-K per ha) to enhance hybrid poplar growth at the Health site. Five passive methods of oxygen delivery were examined, including aeration tubes, gravel addition, and an Oxygen Release Compound (ORC). When ORC was placed in coffee filters above hydrocarbon-contaminated soil, a statistically significant increase of 145% was observed in poplar biomass growth, relative to unamended controls. The ORC in filters also stimulated significant increases in root density. A 15.2-cm interval of soil directly below ORC addition exhibited an increase from 2.6 +/- 1.0 mg/cm3 to 4.8 +/- 1.0 mg/cm3, showing stimulation of root growth in hydrocarbon-stained soil. The positive response of hybrid poplars to oxygen amendments suggests that overcoming oxygen limitation to plants should be considered in phytoremediation projects when soil contamination exerts a high biochemical oxygen demand, such as in former refinery sites.

  9. Stimulation of hybrid poplar growth in petroleum-contaminated soils through oxygen addition and soil nutrient amendments.

    PubMed

    Rentz, Jeremy A; Chapman, Brad; Alvarez, Pedro J J; Schnoor, Jerald L

    2003-01-01

    Hybrid poplar trees (Populus deltoides x nigra DN34) were grown in a green-house using hydrocarbon-contaminated soil from a phytoremediation demonstration site in Health, Ohio. Two independent experiments investigated the effect of nutrient addition on poplar growth and the importance of oxygen addition to root development and plant growth. Biomass measurements, poplar height, and leaf color were used as indicators of plant health in the selection of a 10/5/5 NPK fertilizer applied at 1121 kg/ha (112 kg-N, 24.4 kg-P, 46.5 kg-K per ha) to enhance hybrid poplar growth at the Health site. Five passive methods of oxygen delivery were examined, including aeration tubes, gravel addition, and an Oxygen Release Compound (ORC). When ORC was placed in coffee filters above hydrocarbon-contaminated soil, a statistically significant increase of 145% was observed in poplar biomass growth, relative to unamended controls. The ORC in filters also stimulated significant increases in root density. A 15.2-cm interval of soil directly below ORC addition exhibited an increase from 2.6 +/- 1.0 mg/cm3 to 4.8 +/- 1.0 mg/cm3, showing stimulation of root growth in hydrocarbon-stained soil. The positive response of hybrid poplars to oxygen amendments suggests that overcoming oxygen limitation to plants should be considered in phytoremediation projects when soil contamination exerts a high biochemical oxygen demand, such as in former refinery sites. PMID:12710235

  10. Soil nitrous oxide emissions following crop residue addition: a meta-analysis.

    PubMed

    Chen, Huaihai; Li, Xuechao; Hu, Feng; Shi, Wei

    2013-10-01

    Annual production of crop residues has reached nearly 4 billion metric tons globally. Retention of this large amount of residues on agricultural land can be beneficial to soil C sequestration. Such potential impacts, however, may be offset if residue retention substantially increases soil emissions of N(2)O, a potent greenhouse gas and ozone depletion substance. Residue effects on soil N(2)O emissions have gained considerable attention since early 1990s; yet, it is still a great challenge to predict the magnitude and direction of soil N(2)O emissions following residue amendment. Here, we used a meta-analysis to assess residue impacts on soil N(2)O emissions in relation to soil and residue attributes, i.e., soil pH, soil texture, soil water content, residue C and N input, and residue C : N ratio. Residue effects were negatively associated with C : N ratios, but generally residue amendment could not reduce soil N(2)O emissions, even for C : N ratios well above ca. 30, the threshold for net N immobilization. Residue effects were also comparable to, if not greater than, those of synthetic N fertilizers. In addition, residue effects on soil N(2)O emissions were positively related to the amounts of residue C input as well as residue effects on soil CO(2) respiration. Furthermore, most significant and stimulatory effects occurred at 60-90% soil water-filled pore space and soil pH 7.1-7.8. Stimulatory effects were also present for all soil textures except sand or clay content ≤10%. However, inhibitory effects were found for soils with >90% water-filled pore space. Altogether, our meta-analysis suggests that crop residues played roles beyond N supply for N(2)O production. Perhaps, by stimulating microbial respiration, crop residues enhanced oxygen depletion and therefore promoted anaerobic conditions for denitrification and N(2)O production. Our meta-analysis highlights the necessity to connect the quantity and quality of crop residues with soil properties for predicting

  11. Killing and preserving nematodes in soil samples with chemicals and microwave energy.

    PubMed

    Barker, K R; Gooding, G V; Elder, A S; Eplee, R E

    1972-04-01

    Three basic procedures for treating nematode-bearing soil samples for international shipment or from areas under quarantine were tested for their killing effect and recovery of nematodes by sugar flotation for diagnostic and advisory purposes. These were: fumigation with methyl bromide followed by storage at -15 C; microwave treatment (2450 MHz, 630 w, 2-5 min) followed by addition of FAA + picric acid or 5% Formalin; and adding chemical preservatives (FAA + picric acid, 5% Formalin, NAN, and 2-phenoxyethanol) directly to the soil. Larvae of Heterodera glycines in eggs within cysts were stimulated to hatch by 2-rain exposure to microwaves, and an exposure of 5 rain was required to kill them. Soil type and moisture significantly affected microwave effectiveness. Direct saturation of soil samples with preservative chemical solutions (FAA + picric acid or 5% Formalin) was most effective, and often increased the number of nematodes recovered. The high concentration (2%) of NaN a required for soil sterilization is too hazardous for routine work. NaN, therefore, is not recommended for this purpose.

  12. Rapid methods for classification and quantitative assessment of petroleum hydrocarbons pollution in soil samples using reflectance spectroscopy.

    NASA Astrophysics Data System (ADS)

    Schwartz, G.; Eshel, G.; Ben-Haim, M.; Ben-Dor, E.

    2009-04-01

    Petroleum hydrocarbons (PHC) are one of the most significant environmental polluter (for both soil and water) mainly due to its mass production and use (13.26 million cubic meters of crude oil per day). The commonly used method for PHC determination in soil samples is by PHC extraction from the soil sample using 1,1,2-Trichlorotrifluoroethane (Freon 113) and afterwards determining the total PHC (TPH) by FTIR. This method is expensive and time consuming; in addition the use of Freon 113 was recently prohibited by the EPA. Therefore, there is a great need for alternative methods which are environmental friendly and can rapidly detect low concentrations of petroleum hydrocarbon in soils. The adoption of this approach to evaluate PHC contamination in soils is obvious and a few works have partially demonstrated this application. This study focused on using defused spectral analysis across the VNIR-SWIR region (400-2500 nm) to directly determine PHC in soil samples especially at low concentrations. We used artificially contaminated soil samples (diesel and fuel) that were analyzed by both the common method (extraction with Freon 113) and spectrally. Several statistical models were tested for predicting TPH in soils for a large concentration range (100 - 10000 ppm). More than one hundred field contaminated soil samples have been collected and analyzed in the same manner. Preliminary combined generic models are being tested, for in situ use for quantifying TPH in soils at high precisions levels, as well as identifying fuel type in the soil medium with great success. Our results show that PHC contamination in soils can be evaluated generically in situ, rapidly, accurately, and cost effectively.

  13. Microbial properties explain temporal variation in soil respiration in a grassland subjected to nitrogen addition

    PubMed Central

    Li, Yue; Liu, Yinghui; Wu, Shanmei; Niu, Lei; Tian, Yuqiang

    2015-01-01

    The role of soil microbial variables in shaping the temporal variability of soil respiration has been well acknowledged but is poorly understood, particularly under elevated nitrogen (N) deposition conditions. We measured soil respiration along with soil microbial properties during the early, middle, and late growing seasons in temperate grassland plots that had been treated with N additions of 0, 2, 4, 8, 16, or 32 g N m−2 yr−1 for 10 years. Representing the averages over three observation periods, total (Rs) and heterotrophic (Rh) respiration were highest with 4 g N m−2 yr−1, but autotrophic respiration (Ra) was highest with 8 to 16 g N m−2 yr−1. Also, the responses of Rh and Ra were unsynchronized considering the periods separately. N addition had no significant impact on the temperature sensitivity (Q10) for Rs but inhibited the Q10 for Rh. Significant interactions between observation period and N level occurred in soil respiration components, and the temporal variations in soil respiration components were mostly associated with changes in microbial biomass carbon (MBC) and phospholipid fatty acids (PLFAs). Further observation on soil organic carbon and root biomass is needed to reveal the long-term effect of N deposition on soil C sequestration. PMID:26678303

  14. Microbial properties explain temporal variation in soil respiration in a grassland subjected to nitrogen addition.

    PubMed

    Li, Yue; Liu, Yinghui; Wu, Shanmei; Niu, Lei; Tian, Yuqiang

    2015-12-18

    The role of soil microbial variables in shaping the temporal variability of soil respiration has been well acknowledged but is poorly understood, particularly under elevated nitrogen (N) deposition conditions. We measured soil respiration along with soil microbial properties during the early, middle, and late growing seasons in temperate grassland plots that had been treated with N additions of 0, 2, 4, 8, 16, or 32 g N m(-2) yr(-1) for 10 years. Representing the averages over three observation periods, total (Rs) and heterotrophic (Rh) respiration were highest with 4 g N m(-2) yr(-1), but autotrophic respiration (Ra) was highest with 8 to 16 g N m(-2) yr(-1). Also, the responses of Rh and Ra were unsynchronized considering the periods separately. N addition had no significant impact on the temperature sensitivity (Q10) for Rs but inhibited the Q10 for Rh. Significant interactions between observation period and N level occurred in soil respiration components, and the temporal variations in soil respiration components were mostly associated with changes in microbial biomass carbon (MBC) and phospholipid fatty acids (PLFAs). Further observation on soil organic carbon and root biomass is needed to reveal the long-term effect of N deposition on soil C sequestration.

  15. Microbial properties explain temporal variation in soil respiration in a grassland subjected to nitrogen addition

    NASA Astrophysics Data System (ADS)

    Li, Yue; Liu, Yinghui; Wu, Shanmei; Niu, Lei; Tian, Yuqiang

    2015-12-01

    The role of soil microbial variables in shaping the temporal variability of soil respiration has been well acknowledged but is poorly understood, particularly under elevated nitrogen (N) deposition conditions. We measured soil respiration along with soil microbial properties during the early, middle, and late growing seasons in temperate grassland plots that had been treated with N additions of 0, 2, 4, 8, 16, or 32 g N m-2 yr-1 for 10 years. Representing the averages over three observation periods, total (Rs) and heterotrophic (Rh) respiration were highest with 4 g N m-2 yr-1, but autotrophic respiration (Ra) was highest with 8 to 16 g N m-2 yr-1. Also, the responses of Rh and Ra were unsynchronized considering the periods separately. N addition had no significant impact on the temperature sensitivity (Q10) for Rs but inhibited the Q10 for Rh. Significant interactions between observation period and N level occurred in soil respiration components, and the temporal variations in soil respiration components were mostly associated with changes in microbial biomass carbon (MBC) and phospholipid fatty acids (PLFAs). Further observation on soil organic carbon and root biomass is needed to reveal the long-term effect of N deposition on soil C sequestration.

  16. Metallic phases in the Luna 24 soil samples

    NASA Technical Reports Server (NTRS)

    Friel, J. J.; Goldstein, J. I.

    1977-01-01

    The metal and sulfide phases in the Luna 24 soil samples were studied with the optical microscope and the electron microprobe. The compositions of the metal particles fall into three groups based on their Ni and Co contents: (1) Samples of meteoritic composition which have undergone metamorphism on the lunar surface. (2) Samples of submeteoritic, low Ni and low Co contents, including most of the metal particles observed. These particles are contained in glass and agglutinate particles and were probably formed by the mixing of meteoritic metal with lunar metal produced by the reduction of silicates during shock-impact. (3) Samples of high-CO content probably formed by mixing of meteoritic material with high-Co metal from the mare basalt or by fractional crystallization from a metal silicate melt. The sulfide minerals were also studied. These are almost pure FeS, and crystallized from a late stage liquid in the mare basalt. Three high-Ni sulfides were also found in the glass phase of agglutinates.

  17. Design of a Soil Science practical exercise to understand the soil carbon sequestration after biochar addition

    NASA Astrophysics Data System (ADS)

    Gascó, Gabriel; Cely, Paola; Saa-Requejo, Antonio; Mendez, Ana; Antón, Jose Manuel; Sánchez, Elena; Moratiel, Ruben; Tarquis, Ana M.

    2014-05-01

    The adaptation of the Universities to European Higher Education Area (EHEA) involves changes in the learning system. Students must obtain specific capabilities in the different degrees or masters. For example, in the degree of Agronomy at the Universidad Politécnica de Madrid (UPM, Spain), they must command Soil science, Mathematics or English. Sometimes, There is not a good communication between teachers and it causes that students do not understand the importance of the different subjects of a career. For this reason, teachers of the Soil Science and Mathematics Departments of the UPM designed a common practice to teach to the students the role of soil on the carbon sequestration. The objective of this paper is to explain the followed steps to the design of the practice. Acknowledgement to Universidad Politécnica de Madrid for the Projects in Education Innovation IE12_13-02009 and IE12_13-02012.

  18. Nutrient additions to a tropical rain forest drive substantial soil carbon dioxide losses to the atmosphere

    PubMed Central

    Cleveland, Cory C.; Townsend, Alan R.

    2006-01-01

    Terrestrial biosphere–atmosphere carbon dioxide (CO2) exchange is dominated by tropical forests, where photosynthetic carbon (C) uptake is thought to be phosphorus (P)-limited. In P-poor tropical forests, P may also limit organic matter decomposition and soil C losses. We conducted a field-fertilization experiment to show that P fertilization stimulates soil respiration in a lowland tropical rain forest in Costa Rica. In the early wet season, when soluble organic matter inputs to soil are high, P fertilization drove large increases in soil respiration. Although the P-stimulated increase in soil respiration was largely confined to the dry-to-wet season transition, the seasonal increase was sufficient to drive an 18% annual increase in CO2 efflux from the P-fertilized plots. Nitrogen (N) fertilization caused similar responses, and the net increases in soil respiration in response to the additions of N and P approached annual soil C fluxes in mid-latitude forests. Human activities are altering natural patterns of tropical soil N and P availability by land conversion and enhanced atmospheric deposition. Although our data suggest that the mechanisms driving the observed respiratory responses to increased N and P may be different, the large CO2 losses stimulated by N and P fertilization suggest that knowledge of such patterns and their effects on soil CO2 efflux is critical for understanding the role of tropical forests in a rapidly changing global C cycle. PMID:16793925

  19. Plant interspecific differences in arbuscular mycorrhizal colonization as a result of soil carbon addition.

    PubMed

    Eschen, René; Müller-Schärer, Heinz; Schaffner, Urs

    2013-01-01

    Soil nutrient availability and colonization by arbuscular mycorrhizal fungi are important and potentially interacting factors shaping vegetation composition and succession. We investigated the effect of carbon (C) addition, aimed at reducing soil nutrient availability, on arbuscular mycorrhizal colonization. Seedlings of 27 plant species with different sets of life-history traits (functional group affiliation, life history strategy and nitrophilic status) were grown in pots filled with soil from a nutrient-rich set-aside field and amended with different amounts of C. Mycorrhizal colonization was progressively reduced along the gradient of increasing C addition in 17 out of 27 species, but not in the remaining species. Grasses had lower colonization levels than forbs and legumes and the decline in AM fungal colonization was more pronounced in legumes than in other forbs and grasses. Mycorrhizal colonization did not differ between annual and perennial species, but decreased more rapidly along the gradient of increasing C addition in plants with high Ellenberg N values than in plants with low Ellenberg N values. Soil C addition not only limits plant growth through a reduction in available nutrients, but also reduces mycorrhizal colonization of plant roots. The effect of C addition on mycorrhizal colonization varies among plant functional groups, with legumes experiencing an overproportional reduction in AM fungal colonization along the gradient of increasing C addition. We therefore propose that for a better understanding of vegetation succession on set-aside fields one may consider the interrelationship between plant growth, soil nutrient availability and mycorrhizal colonization of plant roots.

  20. Differences on soil organic carbon stock estimation according to sampling type in Mediterranean areas

    NASA Astrophysics Data System (ADS)

    Parras-Alcántara, Luis; Lozano-García, Beatriz

    2016-04-01

    Soil organic carbon (SOC) is an important part of the global carbon (C) cycle. In addition, SOC is a soil property subject to changes and highly variable in space and time. Consequently, the scientific community is researching the fate of the organic carbon in the ecosystems. In this line, soil organic matter configuration plays an important role in the Soil System (Parras-Alcántara and Lozano García, 2014). Internationally it is known that soil C sequestration is a strategy to mitigate climate change. In this sense, many soil researchers have studied this parameter (SOC). However, many of these studies were carried out arbitrarily using entire soil profiles (ESP) by pedogenetic horizons or soil control sections (SCS) (edaphic controls to different thickness). As a result, the indiscriminate use of both methodologies implies differences with respect to SOC stock (SOCS) quantification. This scenario has been indicated and warned for different researchers (Parras-Alcántara et al., 2015a; Parras-Alcántara et al., 2015b). This research sought to analyze the SOC stock (SOCS) variability using both methods (ESP and SCS) in the Cardeña and Montoro Natural Park (Spain). This nature reserve is a forested area with 385 km2 in southern Spain. Thirty-seven sampling points were selected in the study zone. Each sampling point was analyzed in two different ways, as ESP (by horizons) and as SCS with different depth increments (0-25, 25-50, 50-75 and 75-100 cm). The major goal of this research was to study the SOCS variability at regional scale. The studied soils were classified as Phaeozems, Cambisols, Regosols and Leptosols. The results obtained show an overestimation of SOCS when SCS sampling approach is used compared to ESP. This supports that methodology selection is very important to SOCS quantification. This research is an assessment for modeling SOCS at the regional level in Mediterranean natural areas. References Parras-Alcántara, L., Lozano-García, B., 2014

  1. Modification of sandy soil hydrophysical environment through bagasse additive under laboratory experiment

    NASA Astrophysics Data System (ADS)

    Abd El-Halim, A. A.; Kumlung, Arunsiri

    2015-01-01

    Until now sandy soils can be considered as one roup having common hydrophysical problems. Therefore, a laboratory experiment was conducted to evaluate the influence of bagasse as an amendment to improve hydrophysical properties of sandy soil, through the determination of bulk density, aggregatesize distribution, total porosity, hydraulic conductivity, pore-space structure and water retention. To fulfil this objective, sandy soils were amended with bagasse at the rate of 0, 0.5, 1, 2, 3 and 4% on the dry weight basis. The study results demonstrated that the addition of bagasse to sandy soils in between 3 to 4% on the dry weight basis led to a significant decrease in bulk density, hydraulic conductivity, and rapid-drainable pores, and increase in the total porosity, water-holding pores, fine capillary pores, water retained at field capacity, wilting point, and soil available water as compared with the control treatment

  2. Analysis of core samples from jet grouted soil

    SciTech Connect

    Allan, M.L.; Kukacka, L.E.

    1995-10-01

    Superplasticized cementitious grouts were tested for constructing subsurface containment barriers using jet grouting in July, 1994. The grouts were developed in the Department of Applied Science at Brookhaven National Laboratory. The test site was located close to the Chemical Waste Landfill at Sandia National Laboratories, Albuquerque, NM. Sandia was responsible for the placement contract. The jet grouted soil was exposed to the service environment for one year and core samples were extracted to evaluate selected properties. The cores were tested for strength, density, permeability (hydraulic conductivity) and cementitious content. The tests provided an opportunity to determine the performance of the grouts and grout-treated soil. Several recommendations arise from the results of the core tests. These are: (1) grout of the same mix proportions as the final grout should be used as a drilling fluid in order to preserve the original mix design and utilize the benefits of superplasticizers; (2) a high shear mixer should be used for preparation of the grout; (3) the permeability under unsaturated conditions requires consideration when subsurface barriers are used in the vadose zone; and (4) suitable methods for characterizing the permeability of barriers in-situ should be applied.

  3. Effects of biochar addition to soil on nitrogen fluxes in a winter wheat lysimeter experiment

    NASA Astrophysics Data System (ADS)

    Hüppi, Roman; Leifeld, Jens; Neftel, Albrecht; Conen, Franz; Six, Johan

    2014-05-01

    Biochar is a carbon-rich, porous residue from pyrolysis of biomass that potentially increases crop yields by reducing losses of nitrogen from soils and/or enhancing the uptake of applied fertiliser by the crops. Previous research is scarce about biochar's ability to increase wheat yields in temperate soils or how it changes nitrogen dynamics in the field. In a lysimeter system with two different soils (sandy/silt loam) nitrogen fluxes were traced by isotopic 15N enriched fertiliser to identify changes in nitrous oxide emissions, leaching and plant uptake after biochar addition. 20t/ha woodchip-waste biochar (pH=13) was applied to these soils in four lysimeters per soil type; the same number of lysimeters served as a control. The soils were cropped with winter wheat during the season 2012/2013. 170 kg-N/ha ammonium nitrate fertiliser with 10% 15N was applied in 3 events during the growing season and 15N concentrations where measured at different points in time in plant, soil, leachate and emitted nitrous oxide. After one year the lysimeter system showed no difference between biochar and control treatment in grain- and straw yield or nitrogen uptake. However biochar did reduce nitrous oxide emissions in the silt loam and losses of nitrate leaching in sandy loam. This study indicates potential reduction of nitrogen loss from cropland soil by biochar application but could not confirm increased yields in an intensive wheat production system.

  4. Metal-contaminated soil remediation by means of paper mill sludges addition: chemical and ecotoxicological evaluation.

    PubMed

    Calace, N; Campisi, T; Iacondini, A; Leoni, M; Petronio, B M; Pietroletti, M

    2005-08-01

    Metal pollution of soils is a great environmental problem. The major risks due to metal pollution of soil consist of leaching to groundwater and potential toxicity to plants and/or animals. The objective of this study is to evaluate by means of chemical and ecotoxicological approach the effects of paper mill sludge addition on the mobile metal fraction of polluted metal soils. The study was carried out on acidic soil derived from mining activities and thus polluted with heavy metals, and on two paper mill sludges having different chemical features. The results obtained by leaching experiments showed that the addition of a paper mill sludge, consisting mainly of carbonates, silicates and organic matter, to a heavy-metal polluted soil produces a decrease of available metal forms. The carbonate content seems to play a key role in the chemical stabilisation of metals and consequently in a decrease of toxicity of soil. The leached solutions have a non-toxic effect. The mild remediation by addition of sludge has moreover a lasting effect.

  5. Iodide sorption and partitioning in solid, liquid and gas phases in soil samples collected from Japanese paddy fields.

    PubMed

    Ishikawa, Nao K; Uchida, Shigeo; Tagami, Keiko

    2011-07-01

    Sorption kinetics of iodide (I(-)), which is one of the major inorganic chemical forms of iodine in soil environments, were studied under four sets of experimental conditions characterised by temperature or biological activity. We compared partitioning ratios in solid, liquid and gas phases in soils as well as soil-soil solution distribution coefficients (K(d)s) at two different temperatures 4 and 23 °C, for 63 paddy soil samples collected throughout Japan. Interestingly, (125)I emission from soil was observed; the partitioning ratios in gas phase ranged from 0 to 27 % at 4 °C and from 0 to 42 % at 23 °C. In addition, the authors found that K(d) values at 23 °C had good correlation with pH though there was no correlation between K(d) values at 4 °C and pH because of the difference in biological activity.

  6. Effects of biochar addition on the sorption of polar herbicides in paddy soils

    NASA Astrophysics Data System (ADS)

    Garcia-Jaramillo, Manuel; Cox, Lucía; Hermosín, Mari Carmen; Helmus, Rick; Parsons, John R.; Kalbitz, Karsten

    2016-04-01

    Organic amendments, and their water soluble fraction, induce an important impact on pesticide dissipation in soils, affecting their adsorption and transport processes through various chemical interactions. Although in most cases addition of organic amendments increases sorption, leaching of the pesticides can be either reduced or promoted. Because of that, their effect on pesticide behavior must be assessed in order to optimize their use. The major objectives of this study were to investigate the impact of biochar and biochar water extractable substances (BWES) on the sorption behavior of two polar herbicides, azimsulfuron and penoxsulam, in two amended and unamended paddy soils under flooded conditions. The adsorption - desorption of these herbicides was studied in soils amended with fresh biochar and in soils amended with a washed version of the biochar, simulating the conditions of a soil recently amended and a soil where biochar was applied longer time before and most part of the BWES has been already removed because of the flooded conditions. Therefore, sorption on biochar was assessed before and after removing 80% of its water extractable substances, separately and in combination with each soil (at 2 and 5% w/w). BWES were analyzed by high resolution mass spectrometry. The most abundant fractions present in the high mass range were nitrogen-containing molecules. The aromatic character of the DOC-extracts of the unamended and amended soils, based on the specific UV absorbance at 280 nm (SUVA280), was increased with the amendment in all the conditions tested. Adsorption data of both herbicides fitted very well to the Freundlich equation, with R2 values higher than 0.9 in all the conditions tested. Sorption isotherms were in all cases nonlinear, with Nf values <1, resembling L-type isotherms. Biochar had a very different effect on the sorptive properties of each soil. The highest sorption affinity of azimsulfuron to amended soils was observed for the soils

  7. Additives

    NASA Technical Reports Server (NTRS)

    Smalheer, C. V.

    1973-01-01

    The chemistry of lubricant additives is discussed to show what the additives are chemically and what functions they perform in the lubrication of various kinds of equipment. Current theories regarding the mode of action of lubricant additives are presented. The additive groups discussed include the following: (1) detergents and dispersants, (2) corrosion inhibitors, (3) antioxidants, (4) viscosity index improvers, (5) pour point depressants, and (6) antifouling agents.

  8. Review of sample preparation techniques for the analysis of pesticide residues in soil.

    PubMed

    Tadeo, José L; Pérez, Rosa Ana; Albero, Beatriz; García-Valcárcel, Ana I; Sánchez-Brunete, Consuelo

    2012-01-01

    This paper reviews the sample preparation techniques used for the analysis of pesticides in soil. The present status and recent advances made during the last 5 years in these methods are discussed. The analysis of pesticide residues in soil requires the extraction of analytes from this matrix, followed by a cleanup procedure, when necessary, prior to their instrumental determination. The optimization of sample preparation is a very important part of the method development that can reduce the analysis time, the amount of solvent, and the size of samples. This review considers all aspects of sample preparation, including extraction and cleanup. Classical extraction techniques, such as shaking, Soxhlet, and ultrasonic-assisted extraction, and modern techniques like pressurized liquid extraction, microwave-assisted extraction, solid-phase microextraction and QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) are reviewed. The different cleanup strategies applied for the purification of soil extracts are also discussed. In addition, the application of these techniques to environmental studies is considered.

  9. Transgenic nematodes as biosensors for metal stress in soil pore water samples.

    PubMed

    Anbalagan, Charumathi; Lafayette, Ivan; Antoniou-Kourounioti, Melissa; Haque, Mainul; King, John; Johnsen, Bob; Baillie, David; Gutierrez, Carmen; Martin, Jose A Rodriguez; de Pomerai, David

    2012-03-01

    Caenorhabditis elegans strains carrying stress-reporter green fluorescent protein transgenes were used to explore patterns of response to metals. Multiple stress pathways were induced at high doses by most metals tested, including members of the heat shock, oxidative stress, metallothionein (mtl) and xenobiotic response gene families. A mathematical model (to be published separately) of the gene regulatory circuit controlling mtl production predicted that chemically similar divalent metals (classic inducers) should show additive effects on mtl gene induction, whereas chemically dissimilar metals should show interference. These predictions were verified experimentally; thus cadmium and mercury showed additive effects, whereas ferric iron (a weak inducer) significantly reduced the effect of mercury. We applied a similar battery of tests to diluted samples of soil pore water extracted centrifugally after mixing 20% w/w ultrapure water with air-dried soil from an abandoned lead/zinc mine in the Murcia region of Spain. In addition, metal contents of both soil and soil pore water were determined by ICP-MS, and simplified mixtures of soluble metal salts were tested at equivalent final concentrations. The effects of extracted soil pore water (after tenfold dilution) were closely mimicked by mixtures of its principal component ions, and even by the single most prevalent contaminant (zinc) alone, though other metals modulated its effects both positively and negatively. In general, mixtures containing similar (divalent) metal ions exhibited mainly additive effects, whereas admixture of dissimilar (e.g. trivalent) ions often resulted in interference, reducing overall levels of stress-gene induction. These findings were also consistent with model predictions. PMID:22037694

  10. Microscopic Investigation of Martian Soil Samples at the Phoenix Site

    NASA Astrophysics Data System (ADS)

    Pike, W. T.; Staufer, U.; Hecht, M. H.; Marshall, J.; Team, M. M.

    2008-12-01

    We have used the optical and atomic force microscopes (OM and AFM) of the MECA microscopy station on Phoenix (M. Hecht et al., Microscopy Capabilities of the Microscopy, Electrochemistry, and Conductivity Analyzer , JGR accepted for publication) to image samples within reach of the robot arm and delivered to sets of substrates mounted in a sample wheel. For loading the sample, the wheel was pushed out of the MECA enclosure, exposing only one set of substrates: strong and weak magnets, micro-buckets, silicone and silicon featuring grids of micromachined small holes and posts to capture particles. A thickness of up to 200 micrometers of material can be brought into the microscopy station under a leveling blade before the samples are rotated into the field of view of the microscopes as the substrates are tilted from horizontal to vertical. This tilt can cause the loss of a portion of the material depending on the relative strength of the adhesion forces compared to Martian gravity. The time constraints of sample delivery have so far ensured that any ice would have sublimed prior to delivery. From OM images of fully loaded substrates the particles found so far can be very coarsely grouped into three different categories: 1. subrounded strongly magnetic grains, of both a rough and glassy appearance with different shades of yellow, red, brown and black color in a size range of 50 to 100 micrometers, comprising about 10% of the sample volume; 2. small white flecks of a few micrometers in size, about 0.5% of the sample volume; 3. a majority component of a fine, uniformly coloured orange-reddish dust forming agglomerations from a few tens of microns in diameter to below the resolution of the OM with less magnetic attraction than the larger grains. Using populations on more sparsely populated substrates a size distribution could be estimated. The particle size distribution increases with decreasing size until cut off by the 4-micrometer resolution limit of the OM. The AFM

  11. 49 CFR 199.111 - Retention of samples and additional testing.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY DRUG AND ALCOHOL TESTING Drug Testing § 199.111 Retention of samples and additional testing. (a) Samples that yield positive results on confirmation must be retained by the laboratory in properly...

  12. 40 CFR 80.8 - Sampling methods for gasoline, diesel fuel, fuel additives, and renewable fuels.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... of the Federal Register under 5 U.S.C. 552(a) and 1 CFR part 51. To enforce any edition other than... 40 Protection of Environment 17 2014-07-01 2014-07-01 false Sampling methods for gasoline, diesel... Provisions § 80.8 Sampling methods for gasoline, diesel fuel, fuel additives, and renewable fuels....

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

    NASA Astrophysics Data System (ADS)

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

    Microbial activities have been detected in such extreme terrestrial environments as deep lithosphere, a submarine hydrothermal systems, stratosphere, and Antarctica. Microorganisms have adapted to such harsh environments by evolving their biomolecules. Some of these biomolecules such as enzymes might have different characteristics from those of organisms in ordinary environments. Many biosignatures (or biomarkers) have been proposed to detect microbial activities in such extreme environments. A number of techniques are proposed to evaluate biological activities in extreme environments including cultivation methods, assay of metabolism, and analysis of bioorganic compounds like amino acids and DNA. Enzyme activities are useful signature of extant life in extreme environments. Among many enzymes, phosphatase could be a good indicator of biological activities, since phosphate esters are essential for all the living terrestrial organisms. In addition, alkaline phosphatase is known as a typical zinc-containing metalloenzyme and quite stable in environments. We analyzed phosphatase activities in Antarctica soil samples to see whether they can be used as biosignatures for extant life. In addition, we characterized phosphatases extracted from the Antarctica soil samples, and compared with those obtained from other types of environments. Antarctica surface environments are quite severe environments for life since it is extremely cold and dry and exposed to strong UV and cosmic rays. We tried to evaluate biological activities in Antarctica by measuring phosphatase activities. Surface soil samples are obtained at the Sites 1-8 near Showa Base in Antarctica during the 47th Japan Antarctic exploration mission in 2005-6. Activities of acid phosphatase (ACP) and alkaline phosphatase (ALP) are measured spectrophotometrically after mixing the powdered sample and p-nitrophenyl phosphate solution (pH 6.5 for ACP, pH 8.0 for ALP). ALP was characterized after extraction from soils with

  14. δ(15) N from soil to wine in bulk samples and proline.

    PubMed

    Paolini, Mauro; Ziller, Luca; Bertoldi, Daniela; Bontempo, Luana; Larcher, Roberto; Nicolini, Giorgio; Camin, Federica

    2016-09-01

    The feasibility of using δ(15) N as an additional isotopic marker able to link wine to its area of origin was investigated. The whole production chain (soil-leaves-grape-wine) was considered. Moreover, the research included evaluation of the effect of the fermentation process, the use of different types of yeast and white and red vinification, the addition of nitrogen adjuvants and ultrasound lysis simulating wine ageing. The δ(15) N of grapes and wine was measured in bulk samples and compounds, specifically in proline, for the first time. Despite isotopic fractionation from soil to wine, the δ(15) N values of leaves, grapes, wine and particularly must and wine proline conserved the variability of δ(15) N in the growing soil. Fermentation and ultrasound treatment did not affect the δ(15) N values of grape must, which was therefore conserved in wine. The addition of inorganic or organic adjuvants was able to influence the δ(15) N of bulk wine, depending on the amount and the difference between the δ(15) N of must and that of the adjuvant. The δ(15) N of wine proline was not influenced by adjuvant addition and is therefore the best marker for tracing the geographical origin of wine. Copyright © 2016 John Wiley & Sons, Ltd.

  15. δ(15) N from soil to wine in bulk samples and proline.

    PubMed

    Paolini, Mauro; Ziller, Luca; Bertoldi, Daniela; Bontempo, Luana; Larcher, Roberto; Nicolini, Giorgio; Camin, Federica

    2016-09-01

    The feasibility of using δ(15) N as an additional isotopic marker able to link wine to its area of origin was investigated. The whole production chain (soil-leaves-grape-wine) was considered. Moreover, the research included evaluation of the effect of the fermentation process, the use of different types of yeast and white and red vinification, the addition of nitrogen adjuvants and ultrasound lysis simulating wine ageing. The δ(15) N of grapes and wine was measured in bulk samples and compounds, specifically in proline, for the first time. Despite isotopic fractionation from soil to wine, the δ(15) N values of leaves, grapes, wine and particularly must and wine proline conserved the variability of δ(15) N in the growing soil. Fermentation and ultrasound treatment did not affect the δ(15) N values of grape must, which was therefore conserved in wine. The addition of inorganic or organic adjuvants was able to influence the δ(15) N of bulk wine, depending on the amount and the difference between the δ(15) N of must and that of the adjuvant. The δ(15) N of wine proline was not influenced by adjuvant addition and is therefore the best marker for tracing the geographical origin of wine. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27479606

  16. Electrical properties of lunar soil sample 15301,38

    NASA Technical Reports Server (NTRS)

    Olhoeft, G. R.; Frisillo, A. L.; Strangway, D. W.

    1974-01-01

    Electrical property measurements have been made on an Apollo 15 lunar soil sample in ultrahigh vacuum from room temperature to 827 C for the frequency spectrum from 100 Hz through 1 MHz. The dielectric constant, the total ac loss tangent, and the dc conductivity were measured. The dc conductivity showed no thermal hysteresis, but an irreversible (in vacuum) thermal effect was found in the dielectric loss tangent on heating above 700 C and during the subsequent cooling. This appears to be related to several effects associated with lunar glass above 700 C. The sample also showed characteristic low-frequency dispersion in the dielectric constant with increasing temperature, presumably due to Maxwell-Wagner intergranular effects. The dielectric properties may be fitted to a model involving a Cole-Cole frequency distribution that is relatively temperature-independent below 200 C and follows a Boltzmann temperature distribution with an activation energy of 2.5 eV above 200 C. The dc conductivity is fitted by an exponential temperature distribution and becomes the dominant loss above 700 C.

  17. Psychrotrophic lipase producers from Arctic soil and sediment samples.

    PubMed

    Rasol, R; Rashidah, A R; Nazuha, R Siti Nur; Smykla, J; Maznah, W O Wan; Alias, S A

    2014-01-01

    Culturable microorganisms were successfully isolated from soil and sediment samples collected in 2011 on the northern coast of Hornsund, West Spitsbergen. A total of 63 single colony isolates from three sampling sites obtained were subjected to temperature dependence study to assess whether they are obligate psychrophilic or psychrotrophic strains. From initial temperature screening, only 53 psychrotrophic isolates were selected that are capable of growing between 4-28 degrees C. The rest that were capable of tolerating higher temperatures up to 37 degrees C were not included in this study. These isolates were chosen for lipase enzyme screening confirmation with the standard plate assay of olive oil and fluorescent dye Rhodamine B. Six lipase positive isolates were also subjected for subsequent lipase enzyme plate screening on tributyrin, triolein, olive oil and palm oil agar. Lipase production by these six isolates was further assayed by using colorimetric method with palm oil and olive oil as the substrate. These isolates with promising lipase activity ranging from 20 U/ml up to 160 U/ml on palm oil and olive oil substrate were successfully identified. Molecular identification by using 16S rRNA revealed that five out of six isolates were Gram-negative Proteobacteria and the other one was a Gram-positive Actinobacteria. PMID:25033666

  18. Carbon flux from plants to soil microbes is highly sensitive to nitrogen addition and biochar amendment

    NASA Astrophysics Data System (ADS)

    Kaiser, C.; Solaiman, Z. M.; Kilburn, M. R.; Clode, P. L.; Fuchslueger, L.; Koranda, M.; Murphy, D. V.

    2012-04-01

    The release of carbon through plant roots to the soil has been recognized as a governing factor for soil microbial community composition and decomposition processes, constituting an important control for ecosystem biogeochemical cycles. Moreover, there is increasing awareness that the flux of recently assimilated carbon from plants to the soil may regulate ecosystem response to environmental change, as the rate of the plant-soil carbon transfer will likely be affected by increased plant C assimilation caused by increasing atmospheric CO2 levels. What has received less attention so far is how sensitive the plant-soil C transfer would be to possible regulations coming from belowground, such as soil N addition or microbial community changes resulting from anthropogenic inputs such as biochar amendments. In this study we investigated the size, rate and sensitivity of the transfer of recently assimilated plant C through the root-soil-mycorrhiza-microbial continuum. Wheat plants associated with arbuscular mycorrhizal fungi were grown in split-boxes which were filled either with soil or a soil-biochar mixture. Each split-box consisted of two compartments separated by a membrane which was penetrable for mycorrhizal hyphae but not for roots. Wheat plants were only grown in one compartment while the other compartment served as an extended soil volume which was only accessible by mycorrhizal hyphae associated with the plant roots. After plants were grown for four weeks we used a double-labeling approach with 13C and 15N in order to investigate interactions between C and N flows in the plant-soil-microorganism system. Plants were subjected to an enriched 13CO2 atmosphere for 8 hours during which 15NH4 was added to a subset of split-boxes to either the root-containing or the root-free compartment. Both, 13C and 15N fluxes through the plant-soil continuum were monitored over 24 hours by stable isotope methods (13C phospho-lipid fatty acids by GC-IRMS, 15N/13C in bulk plant

  19. Artificial stimulation of soil amine production by addition of organic carbon and nitrogen transforming enzymes

    NASA Astrophysics Data System (ADS)

    Kieloaho, Antti-Jussi; Parshintsev, Jevgeni; Riekkola, Marja-Liisa; Kulmala, Markku; Pumpanen, Jukka; Heinonsalo, Jussi

    2013-04-01

    The major part of nitrogen (N) in boreal forest soil is in organic form (Soil Organic Nitrogen, SON). One of the main pathways for amine production is the decay of SON in soil. Amino acids react with specific decarboxylase enzymes which transform them to amines. Amino acid turnover time in forest soil is relatively fast (in hours) because amino acids can be used as N and C source by plants and microbes. Therefore, amino acid production by protease enzymes might be the critical step for amine production and release from forest soil. The aim of the study was to artificially introduce enzymes responsible for protein transformation into amino acids (proteases) as well as soil organic matter (SOM) decomposition (laccase and manganese peroxidase) in order to increase SON transformation and amine synthesis. Glucose addition has been shown to induce natural soil protease activity. Bovine serum albumin (BSA) was used as control protein. Treatments were conducted both in Scots pine seedlings containing as well as non-planted microcosms. N transformations were examined, as well as amine concentration in soil. The experiment consisted of eight different treatments; two as controls concerning enzyme addition, four treatments were planted with one year old nursery grown Scots pine (Pinus sylvestris L.) seedlings and four were non-planted. The experiment lasted approximately six months and the treatments with the additions were conducted within one more month. The protease activity was discovered more commonly after the treatment with protease or glucose additions. In planted BSA-control some natural protease activity was found but not in non-planted controls. Different substrate additions did not cause any differences in total N percentage, but the presence of the seedlings diminished soil N% by approximately 20%. In addition, the same effect was clearly seen in dissolved N, NH4+ and NO3-. Plant has exploited the soluble N forms almost entirely from the system, irrespective of

  20. Analysis on Soil Seed Bank Diversity Characteristics and Its Relation with Soil Physical and Chemical Properties after Substrate Addition

    PubMed Central

    He, Mengxuan; Lv, Lingyue; Li, Hongyuan; Meng, Weiqing; Zhao, Na

    2016-01-01

    Aims Considered as an essential measure in the application of soil seed bank (SSB) projects, the mixing of substrate and surface soil can effectively improve soil condition. This research is aimed at exploring the diversity characteristics of SSBs and the relationships between SSBs and soil properties. Methods Canonical correspondence analysis (CCA) was adopted to describe the ordination of SSBs on soil properties’ gradients; multiple linear regressions were adopted to analyze the relationship between average growth height and soil properties, density and soil properties. Results Experimental groups of mixed substrate (the mixture of organic and inorganic substrates) had high diversity indexes, especially the Shannon-Wiener Index compared with those of single substrate. Meanwhile, a higher number of species and increased density were also noted in those of mixed substrate. The best test group, No.16, had the highest diversity indexes with a Shannon-Wiener of 1.898, Simpson of 0.633 and Pielou of 0.717, and also showed the highest density of 14000 germinants /m2 and 21 species. In addition, an improvement of the soil’s chemical and physical properties was noted when the substrates were mixed. The mixed substrate of turfy soil and perlite could effectively enhance the soil moisture content, whilst a mixed substrate of rice husk carbon and vermiculite could improve the content of available potassium (AK) and phosphorus (AP) and strengthen soil fertility. The germinated plants also reflected obvious regularities of ordination on soil factor gradients. Three distinct cluster groups were presented, of which the first cluster was distributed in an area with a relatively higher content of AK and AP; the second cluster was distributed at places with relatively higher soil moisture content; and the third cluster of plants didn’t show any obvious relationship with soil physical and chemical properties. Through CCA analysis, AK and AP were considered the most important

  1. Tank farms backlog soil sample and analysis results supporting a contained-in determination

    SciTech Connect

    Jackson, C.L., Fluor Daniel Hanford

    1997-02-27

    Soil waste is generated from Tank Farms and associated Tank Farms facilities operations. The soil is a mixed waste because it is an environmental media which contains tank waste, a listed mixed waste. The soil is designated with the listed waste codes (FOO1 through F005) which have been applied to all tank wastes. The scope of this report includes Tank Farms soil managed under the Backlog program. The Backlog Tank Farm soil in storage consists of drums and 5 boxes (originally 828 drums). The Backlog Waste Program dealt with 2276 containers of solid waste generated by Tank Farms operations during the time period from 1989 through early 1993. The containers were mismanaged by being left in the field for an extended period of time without being placed into permitted storage. As a corrective action for this situation, these containers were placed in interim storage at the Central Waste Complex (CWC) pending additional characterization. The Backlog Waste Analysis Plan (BWAP) (RL 1993) was written to define how Backlog wastes would be evaluated for proper designation and storage. The BWAP was approved in August 1993 and all work required by the BWAP was completed by July 1994. This document presents results of testing performed in 1992 & 1996 that supports the attainment of a Contained-In Determination for Tank Farm Backlog soils. The analytical data contained in this report is evaluated against a prescribed decision rule. If the decision rule is satisfied then the Washington State Department of ecology (Ecology) may grant a Contained-In Determination. A Contained-In Determination for disposal to an unlined burial trench will be requested from Ecology . The decision rule and testing requirements provided by Ecology are described in the Tank Farms Backlog Soil Sample Analysis Plan (SAP) (WHC 1996).

  2. Phosphate addition enhanced soil inorganic nutrients to a large extent in three tropical forests.

    PubMed

    Zhu, Feifei; Lu, Xiankai; Liu, Lei; Mo, Jiangming

    2015-01-21

    Elevated nitrogen (N) deposition may constrain soil phosphorus (P) and base cation availability in tropical forests, for which limited evidence have yet been available. In this study, we reported responses of soil inorganic nutrients to full factorial N and P treatments in three tropical forests different in initial soil N status (N-saturated old-growth forest and two less-N-rich younger forests). Responses of microbial biomass, annual litterfall production and nutrient input were also monitored. Results showed that N treatments decreased soil inorganic nutrients (except N) in all three forests, but the underlying mechanisms varied depending on forests: through inhibition on litter decomposition in the old-growth forest and through Al(3+) replacement of Ca(2+) in the two younger forests. In contrast, besides great elevation in soil available P, P treatments induced 60%, 50%, 26% increases in sum of exchangeable (K(+)+Ca(2+)+Mg(2+)) in the old-growth and the two younger forests, respectively. These positive effects of P were closely related to P-stimulated microbial biomass and litter nutrient input, implying possible stimulation of nutrient return. Our results suggest that N deposition may result in decreases in soil inorganic nutrients (except N) and that P addition can enhance soil inorganic nutrients to support ecosystem processes in these tropical forests.

  3. Phosphate addition enhanced soil inorganic nutrients to a large extent in three tropical forests

    PubMed Central

    Zhu, Feifei; Lu, Xiankai; Liu, Lei; Mo, Jiangming

    2015-01-01

    Elevated nitrogen (N) deposition may constrain soil phosphorus (P) and base cation availability in tropical forests, for which limited evidence have yet been available. In this study, we reported responses of soil inorganic nutrients to full factorial N and P treatments in three tropical forests different in initial soil N status (N-saturated old-growth forest and two less-N-rich younger forests). Responses of microbial biomass, annual litterfall production and nutrient input were also monitored. Results showed that N treatments decreased soil inorganic nutrients (except N) in all three forests, but the underlying mechanisms varied depending on forests: through inhibition on litter decomposition in the old-growth forest and through Al3+ replacement of Ca2+ in the two younger forests. In contrast, besides great elevation in soil available P, P treatments induced 60%, 50%, 26% increases in sum of exchangeable (K++Ca2++Mg2+) in the old-growth and the two younger forests, respectively. These positive effects of P were closely related to P-stimulated microbial biomass and litter nutrient input, implying possible stimulation of nutrient return. Our results suggest that N deposition may result in decreases in soil inorganic nutrients (except N) and that P addition can enhance soil inorganic nutrients to support ecosystem processes in these tropical forests. PMID:25605567

  4. Eolian additions to late Quaternary alpine soils, Indian Peaks Wilderness Area, Colorado Front Range

    USGS Publications Warehouse

    Muhs, D.R.; Benedict, J.B.

    2006-01-01

    Surface horizons of many alpine soils on Quaternary deposits in high-mountain settings are enriched in silt. The origin of these particles has been debated, particularly in the Rocky Mountain region of North America. The most common explanations are frost shattering of coarser particles and eolian additions from distant sources. We studied soil A horizons on alpine moraines of late-glacial (Satanta Peak) age in the Colorado Front Range. Surface horizons of soils on these moraines are enriched in silt and have a particle size distribution that resembles loess and dust deposits found elsewhere. The compositions of sand and silt fractions of the soils were compared to possible local source rocks, using immobile trace elements Ti, Nb, Zr, Ce, and Y. The sand fractions of soils have a wide range of trace element ratios, similar to the range of values in the local biotite gneiss bedrock. In contrast, silt fractions have narrower ranges of trace element ratios that do not overlap the range of these ratios in biotite gneiss. The particle size and geochemical results support an interpretation that silts in these soils are derived from airborne dust. Eolian silts were most likely derived from distant sources, such as the semiarid North Park and Middle Park basins to the west. We hypothesize that much of the eolian influx to soils of the Front Range occurred during an early to mid-Holocene warm period, when sediment availability in semiarid source basins was at a maximum.

  5. Analysis of zinc in biological samples by flame atomic absorption spectrometry: use of addition calibration technique.

    PubMed

    Dutra, Rosilene L; Cantos, Geny A; Carasek, Eduardo

    2006-01-01

    The quantification of target analytes in complex matrices requires special calibration approaches to compensate for additional capacity or activity in the matrix samples. The standard addition is one of the most important calibration procedures for quantification of analytes in such matrices. However, this technique requires a great number of reagents and material, and it consumes a considerable amount of time throughout the analysis. In this work, a new calibration procedure to analyze biological samples is proposed. The proposed calibration, called the addition calibration technique, was used for the determination of zinc (Zn) in blood serum and erythrocyte samples. The results obtained were compared with those obtained using conventional calibration techniques (standard addition and standard calibration). The proposed addition calibration was validated by recovery tests using blood samples spiked with Zn. The range of recovery for blood serum and erythrocyte samples were 90-132% and 76-112%, respectively. Statistical studies among results obtained by the addition technique and conventional techniques, using a paired two-tailed Student's t-test and linear regression, demonstrated good agreement among them. PMID:16943611

  6. Spectroscopic analyses of soil samples outside Nile Delta of Egypt.

    PubMed

    Fakhry, Ahmed; Osman, Osama; Ezzat, Hend; Ibrahim, Medhat

    2016-11-01

    Soil in Egypt, especially around Delta is exposed to various pollutants which are affecting adversely soil fertility and stability. Humic Acids (HA) as a main part of soil organic matter (SOM) represent the heart of the interaction process of inorganic pollutants with soil. Consequently, Fourier transform infrared spectroscopy (FTIR) and Nuclear magnetic resonances (NMR) were used to characterize soil, sediment and extracted HA. Resulting data confirmed that the HA was responsible for transporting inorganic pollutants from surface to subsurface reaching the ground water, which may represent a high risk on public health. The transport process is coming as carboxyl in surface soil changed into metal carboxylate then transferred into the carboxyl in bottom soil.

  7. Spectroscopic analyses of soil samples outside Nile Delta of Egypt

    NASA Astrophysics Data System (ADS)

    Fakhry, Ahmed; Osman, Osama; Ezzat, Hend; Ibrahim, Medhat

    2016-11-01

    Soil in Egypt, especially around Delta is exposed to various pollutants which are affecting adversely soil fertility and stability. Humic Acids (HA) as a main part of soil organic matter (SOM) represent the heart of the interaction process of inorganic pollutants with soil. Consequently, Fourier transform infrared spectroscopy (FTIR) and Nuclear magnetic resonances (NMR) were used to characterize soil, sediment and extracted HA. Resulting data confirmed that the HA was responsible for transporting inorganic pollutants from surface to subsurface reaching the ground water, which may represent a high risk on public health. The transport process is coming as carboxyl in surface soil changed into metal carboxylate then transferred into the carboxyl in bottom soil.

  8. Spectroscopic analyses of soil samples outside Nile Delta of Egypt.

    PubMed

    Fakhry, Ahmed; Osman, Osama; Ezzat, Hend; Ibrahim, Medhat

    2016-11-01

    Soil in Egypt, especially around Delta is exposed to various pollutants which are affecting adversely soil fertility and stability. Humic Acids (HA) as a main part of soil organic matter (SOM) represent the heart of the interaction process of inorganic pollutants with soil. Consequently, Fourier transform infrared spectroscopy (FTIR) and Nuclear magnetic resonances (NMR) were used to characterize soil, sediment and extracted HA. Resulting data confirmed that the HA was responsible for transporting inorganic pollutants from surface to subsurface reaching the ground water, which may represent a high risk on public health. The transport process is coming as carboxyl in surface soil changed into metal carboxylate then transferred into the carboxyl in bottom soil. PMID:27294554

  9. Ammonia-oxidizing archaea respond positively to inorganic nitrogen addition in desert soils.

    PubMed

    Marusenko, Yevgeniy; Garcia-Pichel, Ferran; Hall, Sharon J

    2015-02-01

    In soils, nitrogen (N) addition typically enhances ammonia oxidation (AO) rates and increases the population density of ammonia-oxidizing bacteria (AOB), but not that of ammonia-oxidizing archaea (AOA). We asked if long-term inorganic N addition also has similar consequences in arid land soils, an understudied yet spatially ubiquitous ecosystem type. Using Sonoran Desert top soils from between and under shrubs within a long-term N-enrichment experiment, we determined community concentration-response kinetics of AO and measured the total and relative abundance of AOA and AOB based on amoA gene abundance. As expected, N addition increased maximum AO rates and the abundance of bacterial amoA genes compared to the controls. Surprisingly, N addition also increased the abundance of archaeal amoA genes. We did not detect any major effects of N addition on ammonia-oxidizing community composition. The ammonia-oxidizing communities in these desert soils were dominated by AOA as expected (78% of amoA gene copies were related to Nitrososphaera), but contained unusually high contributions of Nitrosomonas (18%) and unusually low numbers of Nitrosospira (2%). This study highlights unique traits of ammonia oxidizers in arid lands, which should be considered globally in predictions of AO responses to changes in N availability.

  10. Soil Sampling Plan for the transuranic storage area soil overburden and final report: Soil overburden sampling at the RWMC transuranic storage area

    SciTech Connect

    Stanisich, S.N.

    1994-12-01

    This Soil Sampling Plan (SSP) has been developed to provide detailed procedural guidance for field sampling and chemical and radionuclide analysis of selected areas of soil covering waste stored at the Transuranic Storage Area (TSA) at the Idaho National Engineering Laboratory`s (INEL) Radioactive Waste Management Complex (RWMC). The format and content of this SSP represents a complimentary hybrid of INEL Waste Management--Environmental Restoration Program, and Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) Remedial Investigation/Feasibility Study (RI/FS) sampling guidance documentation. This sampling plan also functions as a Quality Assurance Project Plan (QAPP). The QAPP as a controlling mechanism during sampling to ensure that all data collected are valid, reliabile, and defensible. This document outlines organization, objectives and quality assurance/quality control (QA/QC) activities to achieve the desired data quality goals. The QA/QC requirements for this project are outlined in the Data Collection Quality Assurance Plan (DCQAP) for the Buried Waste Program. The DCQAP is a program plan and does not outline the site specific requirements for the scope of work covered by this SSP.

  11. Bacterial biodegradation of melamine-contaminated aged soil: influence of different pre-culture media or addition of activation material.

    PubMed

    Hatakeyama, Takashi; Takagi, Kazuhiro

    2016-08-01

    This study aimed to investigate the biodegrading potential of Arthrobacter sp. MCO, Arthrobacter sp. CSP, and Nocardioides sp. ATD6 in melamine-contaminated upland soil (melamine: approx. 10.5 mg/kg dry weight) after 30 days of incubation. The soil sample used in this study had undergone annual treatment of lime nitrogen, which included melamine; it was aged for more than 10 years in field. When R2A broth was used as the pre-culture medium, Arthrobacter sp. MCO could degrade 55 % of melamine after 30 days of incubation, but the other strains could hardly degrade melamine (approximately 25 %). The addition of trimethylglycine (betaine) in soil as an activation material enhanced the degradation rate of melamine by each strain; more than 50 % of melamine was degraded by all strains after 30 days of incubation. In particular, strain MCO could degrade 72 % of melamine. When the strains were pre-cultured in R2A broth containing melamine, the degradation rate of melamine in soil increased remarkably. The highest (72 %) melamine degradation rate was noted when strain MCO was used with betaine addition.

  12. Bacterial biodegradation of melamine-contaminated aged soil: influence of different pre-culture media or addition of activation material.

    PubMed

    Hatakeyama, Takashi; Takagi, Kazuhiro

    2016-08-01

    This study aimed to investigate the biodegrading potential of Arthrobacter sp. MCO, Arthrobacter sp. CSP, and Nocardioides sp. ATD6 in melamine-contaminated upland soil (melamine: approx. 10.5 mg/kg dry weight) after 30 days of incubation. The soil sample used in this study had undergone annual treatment of lime nitrogen, which included melamine; it was aged for more than 10 years in field. When R2A broth was used as the pre-culture medium, Arthrobacter sp. MCO could degrade 55 % of melamine after 30 days of incubation, but the other strains could hardly degrade melamine (approximately 25 %). The addition of trimethylglycine (betaine) in soil as an activation material enhanced the degradation rate of melamine by each strain; more than 50 % of melamine was degraded by all strains after 30 days of incubation. In particular, strain MCO could degrade 72 % of melamine. When the strains were pre-cultured in R2A broth containing melamine, the degradation rate of melamine in soil increased remarkably. The highest (72 %) melamine degradation rate was noted when strain MCO was used with betaine addition. PMID:27080407

  13. Charcoal addition to soils in NE England: a carbon sink with environmental co-benefits?

    PubMed

    Bell, M J; Worrall, F

    2011-04-01

    Interest in the application of biochar (charcoal produced during the pyrolysis of biomass) to agricultural land is increasing across the world, recognised as a potential way to capture and store atmospheric carbon. Its interest is heightened by its potential co-benefits for soil quality and fertility. The majority of research has however been undertaken in tropical rather than temperate regions. This study assessed the potential for lump-wood charcoal addition (as a substitute for biochar) to soil types which are typically under arable and forest land-use in North East England. The study was undertaken over a 28 week period and found: i) No significant difference in net ecosystem respiration (NER) between soils containing charcoal and those without, other than in week 1 of the trial. ii) A significantly higher dissolved organic carbon (DOC) flux from soils containing large amounts of charcoal than from those untreated, when planted with ryegrass. iii) That when increased respiration or DOC loss did occur, neither was sufficiently large to alter the carbon sink benefits of charcoal application. iv) That charcoal incorporation resulted in a significantly lower nitrate flux in soil leachate from mineral soils. v) That charcoal incorporation caused significant increases in soil pH, from 6.98 to 7.22 on bare arable soils when 87,500 kg charcoal/ha was applied. Consideration of both the carbon sink and environmental benefits observed here suggests that charcoal application to temperate soils typical of North East England should be considered as a method of carbon sequestration. Before large scale land application is encouraged, further large scale trials should be undertaken to confirm the positive results of this research.

  14. Minimum Additive Waste Stabilization (MAWS), Phase I: Soil washing final report

    SciTech Connect

    1995-08-01

    As a result of the U.S. Department of Energy`s environmental restoration and technology development activities, GTS Duratek, Inc., and its subcontractors have demonstrated an integrated thermal waste treatment system at Fernald, OH, as part the Minimum Additive Waste Stabilization (MAWS) Program. Specifically, MAWS integrates soil washing, vitrification of mixed waste streams, and ion exchange to recycle and remediate process water to achieve, through a synergistic effect, a reduction in waste volume, increased waste loading, and production of a durable, leach-resistant, stable waste form suitable for disposal. This report summarizes the results of the demonstration/testing of the soil washing component of the MAWS system installed at Fernald (Plant 9). The soil washing system was designed to (1) process contaminated soil at a rate of 0.25 cubic yards per hour; (2) reduce overall waste volume and provide consistent-quality silica sand and contaminant concentrates as raw material for vitrification; and (3) release clean soil with uranium levels below 35 pCi/g. Volume reductions expected ranged from 50-80 percent; the actual volume reduction achieved during the demonstration reached 66.5 percent. The activity level of clean soil was reduced to as low as 6 pCi/g from an initial average soil activity level of 17.6 pCi/g (the highest initial level of soil provided for testing was 41 pCi/g). Although the throughput of the soil washing system was inconsistent throughout the testing period, the system was online for sufficient periods to conclude that a rate equivalent to 0.25 cubic yards per hour was achieved.

  15. The responses of soil respiration to nitrogen addition in a temperate grassland in northern China.

    PubMed

    Luo, Qinpu; Gong, Jirui; Zhai, Zhanwei; Pan, Yan; Liu, Min; Xu, Sha; Wang, Yihui; Yang, Lili; Baoyin, Taoge-Tao

    2016-11-01

    Anthropogenic activities have increased nitrogen (N) inputs to grassland ecosystems. Knowledge of the impact of soil N availability on soil respiration (RS) is critical to understand soil carbon balances and their responses to global climate change. A 2-year field experiment was conducted to evaluate the response of RS to soil mineral N in a temperate grassland in northern China. RS, abiotic and biotic factors, and N mineralization were measured in the grassland, at rates of N addition ranging from 0 to 25gNm(-2)yr(-1). Annual and dormant-season RS ranged from 241.34 to 283.64g C m(-2) and from 61.34 to 83.84g C m(-2) respectively. High N application significantly increased RS, possibly due to increased root biomass and increased microbial biomass. High N treatment significantly increased soil NO3-N and inorganic N content compared with the control. The ratio of NO3-N to NH4-N and the N mineralization rate were significantly positively correlated with RS, but NH4-N was not correlated or negatively correlated with RS during the growing season. The temperature sensitivity of RS (Q10) was not significantly affected by N levels, and ranged from 1.90 to 2.20, but decreased marginally significantly at high N. RS outside the growing season is an important component of annual RS, accounting for 25.0 to 29.6% of the total. High N application indirectly stimulated RS by increasing soil NO3-N and net nitrification, thereby eliminating soil N limitations, promoting ecosystem productivity, and increasing soil CO2 efflux. Our results show the importance of distinguishing between NO3-N and NH4-N, as their impact on soil CO2 efflux differed.

  16. The responses of soil respiration to nitrogen addition in a temperate grassland in northern China.

    PubMed

    Luo, Qinpu; Gong, Jirui; Zhai, Zhanwei; Pan, Yan; Liu, Min; Xu, Sha; Wang, Yihui; Yang, Lili; Baoyin, Taoge-Tao

    2016-11-01

    Anthropogenic activities have increased nitrogen (N) inputs to grassland ecosystems. Knowledge of the impact of soil N availability on soil respiration (RS) is critical to understand soil carbon balances and their responses to global climate change. A 2-year field experiment was conducted to evaluate the response of RS to soil mineral N in a temperate grassland in northern China. RS, abiotic and biotic factors, and N mineralization were measured in the grassland, at rates of N addition ranging from 0 to 25gNm(-2)yr(-1). Annual and dormant-season RS ranged from 241.34 to 283.64g C m(-2) and from 61.34 to 83.84g C m(-2) respectively. High N application significantly increased RS, possibly due to increased root biomass and increased microbial biomass. High N treatment significantly increased soil NO3-N and inorganic N content compared with the control. The ratio of NO3-N to NH4-N and the N mineralization rate were significantly positively correlated with RS, but NH4-N was not correlated or negatively correlated with RS during the growing season. The temperature sensitivity of RS (Q10) was not significantly affected by N levels, and ranged from 1.90 to 2.20, but decreased marginally significantly at high N. RS outside the growing season is an important component of annual RS, accounting for 25.0 to 29.6% of the total. High N application indirectly stimulated RS by increasing soil NO3-N and net nitrification, thereby eliminating soil N limitations, promoting ecosystem productivity, and increasing soil CO2 efflux. Our results show the importance of distinguishing between NO3-N and NH4-N, as their impact on soil CO2 efflux differed. PMID:27396319

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

    SciTech Connect

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

    2011-03-01

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

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

    PubMed

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

    2011-03-01

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

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

    PubMed

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

    2011-03-01

    Microbial communities and their associated enzyme activities affect the amount and chemical quality of carbon (C) in soils. Increasing nitrogen (N) deposition, particularly in N-rich tropical forests, is likely to change the composition and behavior of microbial communities and feed back on ecosystem structure and function. This study presents a novel assessment of mechanistic links between microbial responses to N deposition and shifts in soil organic matter (SOM) quality and quantity. We used phospholipid fatty acid (PLFA) analysis and microbial enzyme assays in soils to assess microbial community responses to long-term N additions in two distinct tropical rain forests. We used soil density fractionation and 13C nuclear magnetic resonance (NMR) spectroscopy to measure related changes in SOM pool sizes and chemical quality. Microbial biomass increased in response to N fertilization in both tropical forests and corresponded to declines in pools of low-density SOM. The chemical quality of this soil C pool reflected ecosystem-specific changes in microbial community composition. In the lower-elevation forest, there was an increase in gram-negative bacteria PLFA biomass, and there were significant losses of labile C chemical groups (O-alkyls). In contrast, the upper-elevation tropical forest had an increase in fungal PLFAs with N additions and declines in C groups associated with increased soil C storage (alkyls). The dynamics of microbial enzymatic activities with N addition provided a functional link between changes in microbial community structure and SOM chemistry. Ecosystem-specific changes in microbial community composition are likely to have far-reaching effects on soil carbon storage and cycling. This study indicates that microbial communities in N-rich tropical forests can be sensitive to added N, but we can expect significant variability in how ecosystem structure and function respond to N deposition among tropical forest types. PMID:21608471

  20. The Benefits of Sample Return: Connecting Apollo Soils and Diviner Lunar Radiometer Remote Sensing Data

    NASA Technical Reports Server (NTRS)

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

    2014-01-01

    The Diviner Lunar Radiometer, onboard NASA's Lunar Reconnaissance Orbiter, has produced the first global, high resolution, thermal infrared observations of an airless body. The Moon, which is the most accessible member of this most abundant class of solar system objects, is also the only body for which we have extraterrestrial samples with known spatial context. Here we present the results of a comprehensive study to reproduce an accurate simulated lunar environment, evaluate the most appropriate sample and measurement conditions, collect thermal infrared spectra of a representative suite of Apollo soils, and correlate them with Diviner observations of the lunar surface. We find that analyses of Diviner observations of individual sampling stations and SLE measurements of returned Apollo soils show good agreement, while comparisons to thermal infrared reflectance under terrestrial conditions do not agree well, which underscores the need for SLE measurements and validates the Diviner compositional dataset. Future work includes measurement of additional soils in SLE and cross comparisons with measurements in JPL Simulated Airless Body Emission Laboratory (SABEL).

  1. Remediation of metal polluted soils by phytorremediation combined with biochar addition

    NASA Astrophysics Data System (ADS)

    Méndez, Ana; Paz-Ferreiro, Jorge; Gómez-Limón, Dulce; César Arranz, Julio; Saa, Antonio; Gascó, Gabriel

    2016-04-01

    The main objective of this work is to optimize and quantify the treatment of metal polluted soils through phytoremediation techniques combined with the addition of biochar. Biochar is a carbon rich material obtained by thermal treatment of biomass in inert atmosphere. In recent years, it has been attracted considerable interest due to their positive effect after soil addition. The use of biochar also seems appropriate for the treatment of metal-contaminated soils decreasing their mobility. Biochar properties highly depend on the raw material composition and manufacturing conditions. This paper is based on the use of manure wastes, rich in nutrients and therefore interesting raw materials for biochar production, especially when combined with phytoremediation techniques since the biochar act as conditioner and slow release fertilizer. We are very grateful to Ministerio de Economia y Competitividad (Spain) for financial support under Project CGL2014-58322-R.

  2. Radionuclide Activities in Contaminated Soils: Effects of Sampling Bias on Remediation of Coarse-Grained Soils in Hanford Formation

    SciTech Connect

    Mattigod, Shas V.; Martin, Wayne J.

    2001-08-28

    Only a limited set of particle size-contaminant concentration data is available for soils from the Hanford Site. These data are based on bench-scale tests on single soil samples from one waste site each in operable units 100-BC-1, 100-DR-1, and 100-FR-1, and three samples from the North Pond 300-FF-1 operable unit. The objective of this study was to 1) examine available particle size-contaminant of concern activity and concentration data for 100 and 300 Area soils, 2) assess the effects of sampling bias, 3) suggest sampling protocols, and 4) formulate a method to determine the contaminant of concern activities and concentrations of the whole soil based on the measurements conducted on a finer size fraction of the whole soil.

  3. Effect of alcohol addition on the movement of petroleum hydrocarbon fuels in soil.

    PubMed

    Adam, Gillian; Gamoh, Keiji; Morris, David G; Duncan, Harry

    2002-03-01

    Groundwater contamination by fuel spills from aboveground and underground storage tanks has been of growing concern in recent years. This problem has been magnified by the addition of oxygenates, such as ethanol and methyl-tertiary-butyl ether (MTBE) to fuels to reduce vehicular emissions to the atmosphere. These additives, although beneficial in reducing atmospheric pollution, may, however, increase groundwater contamination due to the co-solvency of petroleum hydrocarbons and by the provision of a preferential substrate for microbial utilisation. With the introduction of ethanol to diesel fuel imminent and the move away from MTBE use in many states of the USA, the environmental implications associated with ethanol additive fuels must be thoroughly investigated. Diesel fuel movement was followed in a 1-m soil column and the effect of ethanol addition to diesel fuel on this movement determined. The addition of 5% ethanol to diesel fuel was found to enhance the downward migration of the diesel fuel components, thus increasing the risk of groundwater contamination. A novel method using soil packed HPLC columns allowed the influence of ethanol on individual aromatic hydrocarbon movement to be studied. The levels of ethanol addition investigated were at the current additive level (approx. 25%) for ethanol additive fuels in Brazil and values above (50%) and below (10%) this level. An aqueous ethanol concentration above 10% was required for any movement to occur. At 25% aqueous ethanol, the majority of hydrocarbons were mobilised and the retention behaviour of the soil column lessened. At 50% aqueous ethanol, all the hydrocarbons were found to move unimpeded through the columns. The retention behaviour of the soil was found to change significantly when both organic matter content and silt/clay content was reduced. Unexpectedly, sandy soil with low organic matter and low silt/clay was found to have a retentive behaviour similar to sandy subsoil with moderate silt

  4. Using site-specific soil samples as a substitution for improved hydrological and nonpoint source predictions.

    PubMed

    Chen, Lei; Wang, Guobo; Zhong, Yucen; Zhao, Xin; Shen, Zhenyao

    2016-08-01

    Soil databases are one of the most important inputs for watershed models, and the quality of soil properties affects how well a model performs. The objectives of this study were to (1) quantify the sensitivity of model outputs to soil properties and to (2) use site-specific soil properties as a substitution for more accurate hydrological and nonpoint source (H/NPS) predictions. Soil samples were collected from a typical mountainous watershed in China, and the impacts of soil sample parameters on H/NPS predictions were quantified using the Soil and Water Assessment Tool (SWAT). The most sensitive parameters related to predicting flow, sediment, and total phosphorus (TP) mainly were the soil hydrological, the channel erosion processes, and the initial soil chemical environment, respectively. When the site-specific soil properties were used, the uncertainties (coefficient of variation) related to predicting the hydrology, sediment and TP decreased by 75∼80 %, 75∼84 %, and 46∼61 %, respectively. Based on changes in the Nash-Sutcliff coefficient, the model performance improved by 4.9 and 19.45 % for the hydrological and sediment model, accordingly. However, site-specific soil properties did not contribute to better TP predictions because of the high spatial variability of the soil P concentrations across the large watershed. Thus, although site-specific soil samples can be used to obtain more accurate H/NPS predictions, more sampling sites are required to apply this method in large watersheds. PMID:27146539

  5. Using site-specific soil samples as a substitution for improved hydrological and nonpoint source predictions.

    PubMed

    Chen, Lei; Wang, Guobo; Zhong, Yucen; Zhao, Xin; Shen, Zhenyao

    2016-08-01

    Soil databases are one of the most important inputs for watershed models, and the quality of soil properties affects how well a model performs. The objectives of this study were to (1) quantify the sensitivity of model outputs to soil properties and to (2) use site-specific soil properties as a substitution for more accurate hydrological and nonpoint source (H/NPS) predictions. Soil samples were collected from a typical mountainous watershed in China, and the impacts of soil sample parameters on H/NPS predictions were quantified using the Soil and Water Assessment Tool (SWAT). The most sensitive parameters related to predicting flow, sediment, and total phosphorus (TP) mainly were the soil hydrological, the channel erosion processes, and the initial soil chemical environment, respectively. When the site-specific soil properties were used, the uncertainties (coefficient of variation) related to predicting the hydrology, sediment and TP decreased by 75∼80 %, 75∼84 %, and 46∼61 %, respectively. Based on changes in the Nash-Sutcliff coefficient, the model performance improved by 4.9 and 19.45 % for the hydrological and sediment model, accordingly. However, site-specific soil properties did not contribute to better TP predictions because of the high spatial variability of the soil P concentrations across the large watershed. Thus, although site-specific soil samples can be used to obtain more accurate H/NPS predictions, more sampling sites are required to apply this method in large watersheds.

  6. FIELD-SCALE STUDIES: HOW DOES SOIL SAMPLE PRETREATMENT AFFECT REPRESENTATIVENESS ? (ABSTRACT)

    EPA Science Inventory

    Samples from field-scale studies are very heterogeneous and can contain large soil and rock particles. Oversize materials are often removed before chemical analysis of the soil samples because it is not practical to include these materials. Is the extracted sample representativ...

  7. FIELD-SCALE STUDIES: HOW DOES SOIL SAMPLE PRETREATMENT AFFECT REPRESENTATIVENESS?

    EPA Science Inventory

    Samples from field-scale studies are very heterogeneous and can contain large soil and rock particles. Oversize materials are often removed before chemical analysis of the soil samples because it is not practical to include these materials. Is the extracted sample representativ...

  8. Sampling and Analysis for Lead in Water and Soil Samples on a University Campus: A Student Research Project.

    ERIC Educational Resources Information Center

    Butala, Steven J.; Zarrabi, Kaveh

    1995-01-01

    Describes a student research project that determined concentrations of lead in water drawn from selected drinking fountains and in selected soil samples on the campus of the University of Nevada, Las Vegas. (18 references) (DDR)

  9. Validation of Sensor-Directed Spatial Simulated Annealing Soil Sampling Strategy.

    PubMed

    Scudiero, Elia; Lesch, Scott M; Corwin, Dennis L

    2016-07-01

    Soil spatial variability has a profound influence on most agronomic and environmental processes at field and landscape scales, including site-specific management, vadose zone hydrology and transport, and soil quality. Mobile sensors are a practical means of mapping spatial variability because their measurements serve as a proxy for many soil properties, provided a sensor-soil calibration is conducted. A viable means of calibrating sensor measurements over soil properties is through linear regression modeling of sensor and target property data. In the present study, two sensor-directed, model-based, sampling scheme delineation methods were compared to validate recent applications of soil apparent electrical conductivity (EC)-directed spatial simulated annealing against the more established EC-directed response surface sampling design (RSSD) approach. A 6.8-ha study area near San Jacinto, CA, was surveyed for EC, and 30 soil sampling locations per sampling strategy were selected. Spatial simulated annealing and RSSD were compared for sensor calibration to a target soil property (i.e., salinity) and for evenness of spatial coverage of the study area, which is beneficial for mapping nontarget soil properties (i.e., those not correlated with EC). The results indicate that the linear modeling EC-salinity calibrations obtained from the two sampling schemes provided salinity maps characterized by similar errors. The maps of nontarget soil properties show similar errors across sampling strategies. The Spatial Simulated Annealing methodology is, therefore, validated, and its use in agronomic and environmental soil science applications is justified. PMID:27380070

  10. Increased loss of soil-derived carbon in response to litter addition and temperature

    NASA Astrophysics Data System (ADS)

    Creamer, C.; Krull, E. S.; Sanderman, J.; Farrell, M.

    2013-12-01

    In order to predict the response of soil organic matter (SOM) to increasing temperatures, a mechanistic understanding of the interactions between OM quality, OM availability, and microbial community structure and function is needed. We used short-term incubations of 13C enriched (20 atom%) fresh and pre-incubated eucalyptus leaf litter in an Australian woodland soil to determine changes in allocation of C to various OM pools, as dictated by microbial activity, in response to temperature and substrate quality. The quantity and isotopic composition of microbial phospholipid fatty acids (PLFA) and dissolved organic C (DOC) were measured along with the quantity of dissolved inorganic and organic nitrogen at four destructive time points. The quantity and isotopic composition of respired CO2 was measured throughout the incubation. Although the temperature sensitivities of the two litters were similar (despite different chemical compositions), soil-C was significantly more temperature sensitive than litter-C. We also observed negative priming of soil-C in the fresh litter treatment and positive priming of soil-C in the pre-incubated litter treatment relative to the control (no litter addition). The extent of positive priming in the pre-incubated litter treatment also increased significantly with temperature. The quantity of soil-derived DOC was consistent between both litter treatments and the control, confirming that differences in soil-C availability were not controlling the observed differences in soil-C mineralization. In contrast, dissolved N was significantly higher in the pre-incubated litter treatment and increased with temperature, suggesting enhanced SOM decomposition in the pre-incubated litter treatment resulted in greater N cycling, production, or destabilization from SOM. The pre-incubated litter treatment also had greater proportions of PLFA that predominately cycled soil-derived OM (gram-positive bacteria), and increased in response to elevated temperature

  11. Total elemental composition analysis of soil samples using the PIXE technique

    NASA Astrophysics Data System (ADS)

    Bolormaa, Oyuntsetseg; Baasansuren, Jamsranjav; Kawasaki, Katsunori; Watanabe, Makiko; Hattroi, Toshiyuki

    2007-09-01

    The determination of major and trace element contents in soils was developed by acid digestion method combined with particle-induced X-ray emission spectrometry (PIXE). The digestion of soils was achieved by using nitric acid (HNO3), hydrochloric acid HCl and hydrogen peroxide (H2O2) with repeated additions. A 20 μL aliquot from the digested samples was evaporated on the Nuclepore Track-Etch Membrane and irradiated by the 2.5 MeV proton beam from the single-end type Van de Graaff accelerator. The accuracy of this methodology was estimated based on series of measurements done for a reference material of soil CRM 023-050. The proposed experimental procedure was shown to have good reproducibility of the experimental results. The corresponding limits of detection (LODs) for Na, Mg, Al, P, S, Cl, K, Cr, Mn, Fe, Ni, Cu, Zn, As, Sr, Mo and Cd were estimated. Other soil characteristics such as total carbon (TC) and nitrogen (TN) content, pH and electrical conductivity (EC) were also measured.

  12. STATISTICAL SAMPLING APPROACH FOR CLOSING A SOIL VENTING SITE

    EPA Science Inventory

    The USEPA allowed the Performing Parties (PPs) to perform a soil vapor extraction process to a site contaminated by volatile organic compounds (VOC), contingent upon the process reducing the VOC concentrations in the soil by 75% within one year. An innovative injection-extraction...

  13. Central Colorado Assessment Project (CCAP)-Geochemical data for rock, sediment, soil, and concentrate sample media

    USGS Publications Warehouse

    Granitto, Matthew; DeWitt, Ed H.; Klein, Terry L.

    2010-01-01

    This database was initiated, designed, and populated to collect and integrate geochemical data from central Colorado in order to facilitate geologic mapping, petrologic studies, mineral resource assessment, definition of geochemical baseline values and statistics, environmental impact assessment, and medical geology. The Microsoft Access database serves as a geochemical data warehouse in support of the Central Colorado Assessment Project (CCAP) and contains data tables describing historical and new quantitative and qualitative geochemical analyses determined by 70 analytical laboratory and field methods for 47,478 rock, sediment, soil, and heavy-mineral concentrate samples. Most samples were collected by U.S. Geological Survey (USGS) personnel and analyzed either in the analytical laboratories of the USGS or by contract with commercial analytical laboratories. These data represent analyses of samples collected as part of various USGS programs and projects. In addition, geochemical data from 7,470 sediment and soil samples collected and analyzed under the Atomic Energy Commission National Uranium Resource Evaluation (NURE) Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) program (henceforth called NURE) have been included in this database. In addition to data from 2,377 samples collected and analyzed under CCAP, this dataset includes archived geochemical data originally entered into the in-house Rock Analysis Storage System (RASS) database (used by the USGS from the mid-1960s through the late 1980s) and the in-house PLUTO database (used by the USGS from the mid-1970s through the mid-1990s). All of these data are maintained in the Oracle-based National Geochemical Database (NGDB). Retrievals from the NGDB and from the NURE database were used to generate most of this dataset. In addition, USGS data that have been excluded previously from the NGDB because the data predate earliest USGS geochemical databases, or were once excluded for programmatic reasons

  14. Occurrence of Leptospira DNA in water and soil samples collected in eastern Poland.

    PubMed

    Wójcik-Fatla, Angelina; Zając, Violetta; Wasiński, Bernard; Sroka, Jacek; Cisak, Ewa; Sawczyn, Anna; Dutkiewicz, Jacek

    2014-01-01

    Leptospira is an important re-emerging zoonotic human pathogen, disseminated by sick and carrier animals, water and soil. Weather calamities, such as flooding or cyclones favour the spreading of these bacteria. To check a potential role of natural water and soil in the persistence and spread of Leptospira on the territory of eastern Poland, 40 samples of natural water and 40 samples of soil were collected from areas exposed to flooding, and 64 samples of natural water and 68 samples of soil were collected from areas not exposed to flooding. Samples of water were taken from various reservoirs (rivers, natural lakes, artificial lakes, canals, ponds, farm wells) and samples of soils were taken at the distance of 1-3 meters from the edge of the reservoirs. The samples were examined for the presence of Leptospira DNA by nested-PCR. Two out of 40 samples of water (5.0%) collected from the area exposed to flooding showed the presence of Leptospira DNA, while all 40 samples of soil from this area were negative. All samples of water and soil (64 and 68, respectively) collected from the areas not exposed to flooding were negative. No significant difference were found between the results obtained in the areas exposed and not exposed to flooding. In conclusion, these results suggest that water and soil have only limited significance in the persistence and dissemination of Leptospira in eastern Poland. PMID:25528911

  15. Evaluation of sampling techniques to characterize topographically-dependent variability for soil moisture downscaling

    NASA Astrophysics Data System (ADS)

    Werbylo, Kevin L.; Niemann, Jeffrey D.

    2014-08-01

    Downscaling methods have been proposed to estimate catchment-scale soil moisture patterns from coarser resolution patterns. These methods usually infer the fine-scale variability in soil moisture using variations in ancillary variables like topographic attributes that have relationships to soil moisture. Previously, such relationships have been observed in catchments using soil moisture observations taken on uniform grids at hundreds of locations on multiple dates, but collecting data in this manner limits the applicability of this approach. The objective of this paper is to evaluate the effectiveness of two strategic sampling techniques for characterizing the relationships between topographic attributes and soil moisture for the purpose of constraining downscaling methods. The strategic sampling methods are conditioned Latin hypercube sampling (cLHS) and stratified random sampling (SRS). Each sampling method is used to select a limited number of locations or dates for soil moisture monitoring at three catchments with detailed soil moisture datasets. These samples are then used to calibrate two available downscaling methods, and the effectiveness of the sampling methods is evaluated by the ability of the downscaling methods to reproduce the known soil moisture patterns. cLHS outperforms random sampling in almost every case considered. SRS usually performs better than cLHS when very few locations are sampled, but it can perform worse than random sampling for intermediate and large numbers of locations.

  16. Effects of nitrogen addition on soil microbes and their implications for soil C emission in the Gurbantunggut Desert, center of the Eurasian Continent.

    PubMed

    Huang, Gang; Cao, Yan Feng; Wang, Bin; Li, Yan

    2015-05-15

    Nitrogen (N) deposition can influence carbon cycling of terrestrial ecosystems. However, a general recognition of how soil microorganisms respond to increasing N deposition is not yet reached. We explored soil microbial responses to two levels of N addition (2.5 and 5 gN m(-2) yr(-1)) in interplant soil and beneath shrubs of Haloxylon ammodendron and their consequences to soil respiration in the Gurbantunggut Desert, northwestern China from 2011 to 2013. Microbial biomass and respiration were significantly higher beneath H. ammodendron than in interplant soil. The responses of microbial biomass carbon (MBC) and microbial respiration (MR) showed opposite responses to N addition in interplant and beneath H. ammodendron. N addition slightly increased MBC and MR in interplant soil and decreased them beneath H. ammodendron, with a significant inhibition only in 2012. N addition had no impacts on the total microbial physiological activity, but N addition decreased the labile carbon substrate utilization beneath H. ammodendron when N addition level was high. Phospholipid fatty acid (PLFA) analysis showed that N addition did not alter the soil microbial community structure as evidenced by the similar ratios of fungal to bacterial PLFAs and gram-negative to gram-positive bacterial PLFAs. Microbial biomass and respiration showed close correlations with soil water content and dissolved carbon, and they were independent of soil inorganic nitrogen across three years. Our study suggests that N addition effects on soil microorganisms and carbon emission are dependent on the respiratory substrates and water availability in the desert ecosystem.

  17. Insights into stable isotope characterization to monitor the signification of soil water sampling for environmental studies dealing with soil water dynamics through the unsaturated zone

    NASA Astrophysics Data System (ADS)

    Brenot, Agnès; Benoît, Marc; Carignan, Jean; France-Lanord, Christian

    2015-11-01

    Porous cup samplers and drainage samplers are two of the broadly used techniques to monitor soil water for agronomical studies. This study provides further insight into the sample signification of these two sampling techniques. For that purpose, temporal variations of soil water δD and δ18O values collected by these two techniques have been monitored for an experimental field studied by INRA. The stable isotope data acquired provide further evidence that soil water samples collected by these two techniques are not equivalent and correspond to different water dynamics in soils: 1) quick infiltration along preferential flow paths for drainage (short residence time) and 2) water with longer residence time for porous cups. This implies that stable isotopic tools could be useful to provide additional information to "classical" monitoring of soil water. This could be of particular interest to estimate the residence time of soil water and could be relevant to follow the effectiveness of agricultural pressure reduction programs on natural water ecosystems.

  18. RAPID SEPARATION METHOD FOR 237NP AND PU ISOTOPES IN LARGE SOIL SAMPLES

    SciTech Connect

    Maxwell, S.; Culligan, B.; Noyes, G.

    2010-07-26

    A new rapid method for the determination of {sup 237}Np and Pu isotopes in soil and sediment samples has been developed at the Savannah River Site Environmental Lab (Aiken, SC, USA) that can be used for large soil samples. The new soil method utilizes an acid leaching method, iron/titanium hydroxide precipitation, a lanthanum fluoride soil matrix removal step, and a rapid column separation process with TEVA Resin. The large soil matrix is removed easily and rapidly using this two simple precipitations with high chemical recoveries and effective removal of interferences. Vacuum box technology and rapid flow rates are used to reduce analytical time.

  19. Global change and biological soil crusts: Effects of ultraviolet augmentation under altered precipitation regimes and nitrogen additions

    USGS Publications Warehouse

    Belnap, J.; Phillips, S.L.; Flint, S.; Money, J.; Caldwell, M.

    2008-01-01

    Biological soil crusts (BSCs), a consortium of cyanobacteria, lichens, and mosses, are essential in most dryland ecosystems. As these organisms are relatively immobile and occur on the soil surface, they are exposed to high levels of ultraviolet (UV) radiation and atmospheric nitrogen (N) deposition, rising temperatures, and alterations in precipitation patterns. In this study, we applied treatments to three types of BSCs (early, medium, and late successional) over three time periods (spring, summer, and spring-fall). In the first year, we augmented UV and altered precipitation patterns, and in the second year, we augmented UV and N. In the first year, with average air temperatures, we saw little response to our treatments except quantum yield, which was reduced in dark BSCs during one of three sample times and in Collema BSCs two of three sample times. There was more response to UV augmentation the second year when air temperatures were above average. Declines were seen in 21% of the measured variables, including quantum yield, chlorophyll a, UV-protective pigments, nitrogenase activity, and extracellular polysaccharides. N additions had some negative effects on light and dark BSCs, including the reduction of quantum yield, ??-carotene, nitrogenase activity, scytonemin, and xanthophylls. N addition had no effects on the Collema BSCs. When N was added to samples that had received augmented UV, there were only limited effects relative to samples that received UV without N. These results indicate that the negative effect of UV and altered precipitation on BSCs will be heightened as global temperatures increase, and that as their ability to produce UV-protective pigments is compromised, physiological functioning will be impaired. N deposition will only ameliorate UV impacts in a limited number of cases. Overall, increases in UV will likely lead to lowered productivity and increased mortality in BSCs through time, which, in turn, will reduce their ability to contribute

  20. Phosphate addition and plant species alters microbial community structure in acidic upland grassland soil.

    PubMed

    Rooney, Deirdre C; Clipson, Nicholas J W

    2009-01-01

    Agricultural improvement (addition of fertilizers, liming) of seminatural acidic grasslands across Ireland and the UK has resulted in significant shifts in floristic composition, soil chemistry, and microbial community structure. Although several factors have been proposed as responsible for driving shifts in microbial communities, the exact causes of such changes are not well defined. Phosphate was added to grassland microcosms to investigate the effect on fungal and bacterial communities. Plant species typical of unimproved grasslands (Agrostis capillaris, Festuca ovina) and agriculturally improved grasslands (Lolium perenne) were grown, and phosphate was added 25 days after seed germination, with harvesting after a further 50 days. Phosphate addition significantly increased root biomass (p < 0.001) and shoot biomass (p < 0.05), soil pH (by 0.1 U), and microbial activity (by 5.33 mg triphenylformazan [TPF] g(-1) soil; p < 0.001). A slight decrease (by 0.257 mg biomass-C g(-1) soil; p < 0.05) in microbial biomass after phosphate addition was found. The presence of plant species significantly decreased soil pH (p < 0.05; by up to 0.2 U) and increased microbial activity (by up to 6.02 mg TPF g(-1) soil) but had no significant effect on microbial biomass. Microbial communities were profiled using automated ribosomal intergenic spacer analysis. Multidimensional scaling plots and canonical correspondence analysis revealed that phosphate addition and its interactions with upland grassland plant species resulted in considerable changes in the fungal and bacterial communities of upland soil. The fungal community structure was significantly affected by both phosphate (R = 0.948) and plant species (R = 0.857), and the bacterial community structure was also significantly affected by phosphate (R = 0.758) and plant species (R = 0.753). Differences in microbial community structure following P addition were also revealed by similarity percentage analysis. These data suggest

  1. Changes in the enzymatic activity of soil samples upon their storage

    NASA Astrophysics Data System (ADS)

    Dadenko, E. V.; Kazeev, K. Sh.; Kolesnikov, S. I.; Val'Kov, V. F.

    2009-12-01

    The influence of the duration and conditions of storage of soil samples on the activity of soil enzymes (catalase, β-fructofuranosidase, and dehydrogenase) was studied for the main soils of southern Russia (different subtypes of chernozems, chestnut soils, brown forest soils, gray forest soils, solonetzes, and solonchaks). The following soil storage conditions were tested: (1) the air-dry state at room temperature, (2) the airdry state at a low positive (in a refrigerator, +4°C) temperature, (3) naturally moist samples at a low positive temperature, and (4) naturally moist samples at a negative (in a freezer, -5°C) temperature. It was found that the sample storing caused significant changes in the enzymatic activities, which depended on the soil type, the land use, the type of enzyme, and the duration and conditions of the sample storage. In the course of the storage, the changes in the enzymatic activity had a nonlinear character. The maximum changes were observed in the initial period (up to 12 weeks). Then, a very gradual decrease in the activity of the studied enzymes was observed. Upon the long-term (>12 weeks) storage under the different conditions, the difference in the activities of the soil enzymes became less pronounced. The storage of soil samples in the air-dried state at room temperature can be recommended for mass investigations.

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

    USGS Publications Warehouse

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

    2011-01-01

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

  3. Additive quantification on polymer thin films by ToF-SIMS: aging sample effects

    NASA Astrophysics Data System (ADS)

    Poleunis, Claude; Médard, Nicolas; Bertrand, Patrick

    2004-06-01

    Thin films (150 nm) of an amorphous polyester (polyethylene(terephthalate-isophthalate)) containing variable concentrations of an antioxidant (Irgafos™ 168) and a UV-stabilizer (Hostavin™ N30) have been prepared by spin-coating. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) results showed, in the case of a single additive system (antioxidant), that the additive intensity increased on the polymer surface during the first five aging days (exudation phenomenon), followed by an intensity decrease, which was related to the adsorption of hydrocarbon contaminations on the sample surface. This kinetic competition was observed whatever the used additive concentration. In the case of the binary additive system (antioxidant and UV-stabilizer), the antioxidant behavior was similar to the single additive system, whereas, the UV-stabilizer evolution corresponded to an additive depletion, followed by an exudation. These results indicate that it is necessary to be very careful when comparing ToF-SIMS data for additive quantification on polymer surfaces. It is strongly recommended to compare samples having the same aging time, because the surface composition was seen to be strongly dependent of the aging time.

  4. 31. VIEW FROM SOUTHWEST TO CORNER WHERE SAMPLING/CRUSHING ADDITIONS ABUT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    31. VIEW FROM SOUTHWEST TO CORNER WHERE SAMPLING/CRUSHING ADDITIONS ABUT CRUSHED OXIDIZED ORE BIN. INTACT BARREN SOLUTION TANK VISIBLE IN FRONT OF CRUSHED ORE BIN. - Bald Mountain Gold Mill, Nevada Gulch at head of False Bottom Creek, Lead, Lawrence County, SD

  5. Arthrobacter deserti sp. nov., isolated from a desert soil sample.

    PubMed

    Hu, Qing-Wen; Chu, Xiao; Xiao, Min; Li, Chang-Tian; Yan, Zheng-Fei; Hozzein, Wael N; Kim, Chang-Jin; Zhi, Xiao-Yang; Li, Wen-Jun

    2016-05-01

    A Gram-stain-positive, non-motile, rod-shaped, catalase-positive and oxidase-negative bacterium, designated YIM CS25T, was isolated from a soil sample collected from Turpan desert in Xinjiang Uyghur Autonomous Region, north-western China. The isolate grew at 15-40 °C, at pH 6.0-8.0 and with 0-6 % (w/v) NaCl. The phylogenetic trees based on 16S rRNA gene sequences revealed that strain YIM CS25T belonged to the genus Arthrobacter and was closely related to Arthrobacter halodurans JSM 078085T (95.89 % similarity). The peptidoglycan type contained lysine, alanine and glutamic acid. The major whole-cell sugars were galactose, glucose and ribose. The isolate contained diphosphatidylglycerol, phosphatidylglycerol and phosphatidylinositol as the major polar lipids and MK-9 (H2) as the predominant menaquinone. The major cellular fatty acids were anteiso-C15 : 0, iso-C15 : 0, anteiso-C17 : 0, iso-C16 : 0 and anteiso-C17 : 1ω9c. The genomic DNA G+C content was 68.3 mol%. On the basis of phylogenetic, phenotypic and chemotaxonomic analysis, strain YIM CS25T is considered to represent a novel species of the genus Arthrobacter, for which the name Arthrobacter deserti sp. nov. is proposed. The type strain is YIM CS25T ( = KCTC 39544T = CGMCC 1.15091T). PMID:26908080

  6. An Efficient Sampling Technique for Observing Topographically-Dependent Spatial Variability in Catchment-Scale Soil Moisture Patterns

    NASA Astrophysics Data System (ADS)

    Werbylo, K. L.; Niemann, J. D.

    2012-12-01

    stratifications for each variable or the number of locations sampled in each joint stratification. The locations selected from the stratified sampling method can also be supplemented with random locations. The method is applied to three different catchments: Tarrawarra, Satellite Station, and Cache la Poudre. The observations are used to calibrate a conceptual model known as the Equilibrium Moisture from Topography (EMT) model and an empirical model based on empirical orthogonal function (EOF) analysis. The efficiency of the sampling method is evaluated by the models' ability to reproduce the soil moisture values at unobserved locations. The stratified method is also compared to a random sampling method. The results show that both the random and stratified sampling methods can characterize the soil moisture variation with many fewer locations than have been collected previously. In addition, the stratified sampling method exhibits much better performance than random sampling when relatively few observations are collected.

  7. Effect of sulfur additions on soil and the nutrition of wheat

    SciTech Connect

    Mahler, R.J.; Maples, R.L.

    1987-01-01

    A field experiment was conducted for two years to determine the effects of four sulfur (S) sources applied at various rates on the elemental composition of Coker 747/sup 3/ wheat and on the soil S concentration. The concentration of S in plants increased by all sources of applied S. Increased S in the soil from S application decreased P concentrations in plants regardless of the S source used. Sulfur additions did not significantly affect the concentrations of Cu, Ca, Mg, or N in plants. The concentrations of Mn, Zn, and Fe in plants either increased or decreased depending on S source used. Analysis of the silt loam soil to a depth of 90 cm revealed that applied S moved readily from the surface to the lower depths and that the elemental form of S moved less rapidly than the more soluble forms of applied S.

  8. The response of soil organic matter decomposition and carbon cycling to temperature increase and nitrogen addition

    NASA Astrophysics Data System (ADS)

    Choi, I.; Kang, M.; Choi, J.

    2012-12-01

    Global warming caused by greenhouse effects has raised the worldwide air temperature by 1.4~5.8°C from the pre-industrial level. It has been known that the enhanced air temperature leads to increase the rate of soil organic matter decomposition. The enhanced soil organic matter decomposition could increase the emission of GHG (Green House Gas-mostly CO2, CH4) from the terrestrial ecosystem. GHG emission from the decomposition of soil organic matter can be affected by N deposition. N deposition of Asia has significantly grown from 1000mg N m2yr-1 to 2000mg N m2yr-1during the period of 1990s. It is expected that large area of South and East Asia will receive as large as 5000mg N m2yr-1of nitrogen in the future. Therefore, it is interesting to investigate the effects of global change factors, such as elevated temperature and N deposition on GHG emission from the terrestrial ecosystem. Growth chamber experiments were conducted under the enhanced air temperature and N addition (controlled at 10°C(30°C), 20°C(40°C) from ambient air temperature 18°C/23°C(day/night)) and GHG(CH4,CO2)was measured using gas chromatograph. Since combined changes in temperature and N deposition are sensitive to litter quantity and quality, especially C:N ratio of organic material, we select three sites with different C:N ratio (rice paddy, forest, wetland) in the southern part of Han river in Korea. Our results show that, for the case of rice paddy and forest, CO2 flux at 30°C was higher than at 40°C. However, wetland soil produces higher CO2 flux at 40°C than at 30°C. While CH4 flux was not detected at 30°C for all of three soils, only wetland soil produced CH4 flux at 40°C. Every flux under the condition of N addition was higher than that of N limitation. The GHG fluxes clearly related to the temperature, N concentration difference and soil types. Long term laboratory experiments are needed in three different soil types to determine how different soil type affects GHG by

  9. A Review of Metal Concentrations Measured in Surface Soil Samples Collected on and Around the Hanford Site

    SciTech Connect

    Fritz, Brad G.

    2009-07-27

    The data used in this report was collected by two separate projects. The Surface Environmental Surveillance Project collected routine samples in 2008 at 41 locations on and around the Hanford Site, and had them analyzed for metals in addition to the normal radiological constituents. In 2004 and 2005, soil samples were collected at 117 locations on the Hanford Reach National Monument (HRNM) in support of the radiological release of that property. In 2008, archived HRNM soil samples were analyzed for metals to supplement the radiological analyses. Concentration results for 30 individual metals were generated by the analytical methods. Selenium and antimony were not measured at detectable concentrations in most of the samples. Mercury was detected in about half of the samples analyzed. All other constituents were measured at detectable concentrations in nearly all samples analyzed. The average concentrations measured in this study were well below the soil cleanup levels for unrestricted land use established by the Model Toxics Control Act (MTCA). In addition to the average concentration being less than the benchmark, the 90th percentile concentration was also lower than the benchmark for the metals included in the MTCA. The results indicate that the measured concentrations of metals in surface soil were within the expected natural range of concentrations.

  10. Studies of levels of biogenic amines in meat samples in relation to the content of additives.

    PubMed

    Jastrzębska, Aneta; Kowalska, Sylwia; Szłyk, Edward

    2016-01-01

    The impact of meat additives on the concentration of biogenic amines and the quality of meat was studied. Fresh white and red meat samples were fortified with the following food additives: citric and lactic acids, disodium diphosphate, sodium nitrite, sodium metabisulphite, potassium sorbate, sodium chloride, ascorbic acid, α-tocopherol, propyl 3,4,5-trihydroxybenzoate (propyl gallate) and butylated hydroxyanisole. The content of spermine, spermidine, putrescine, cadaverine, histamine, tyramine, tryptamine and 2-phenylethylamine was determined by capillary isotachophoretic methods in meat samples (fresh and fortified) during four days of storage at 4°C. The results were applied to estimate the impact of the tested additives on the formation of biogenic amines in white and red meat. For all tested meats, sodium nitrite, sodium chloride and disodium diphosphate showed the best inhibition. However, cadaverine and putrescine were characterised by the biggest changes in concentration during the storage time of all the additives. Based on the presented data for the content of biogenic amines in meat samples analysed as a function of storage time and additives, we suggest that cadaverine and putrescine have a significant impact on meat quality. PMID:26515667

  11. Studies of levels of biogenic amines in meat samples in relation to the content of additives.

    PubMed

    Jastrzębska, Aneta; Kowalska, Sylwia; Szłyk, Edward

    2016-01-01

    The impact of meat additives on the concentration of biogenic amines and the quality of meat was studied. Fresh white and red meat samples were fortified with the following food additives: citric and lactic acids, disodium diphosphate, sodium nitrite, sodium metabisulphite, potassium sorbate, sodium chloride, ascorbic acid, α-tocopherol, propyl 3,4,5-trihydroxybenzoate (propyl gallate) and butylated hydroxyanisole. The content of spermine, spermidine, putrescine, cadaverine, histamine, tyramine, tryptamine and 2-phenylethylamine was determined by capillary isotachophoretic methods in meat samples (fresh and fortified) during four days of storage at 4°C. The results were applied to estimate the impact of the tested additives on the formation of biogenic amines in white and red meat. For all tested meats, sodium nitrite, sodium chloride and disodium diphosphate showed the best inhibition. However, cadaverine and putrescine were characterised by the biggest changes in concentration during the storage time of all the additives. Based on the presented data for the content of biogenic amines in meat samples analysed as a function of storage time and additives, we suggest that cadaverine and putrescine have a significant impact on meat quality.

  12. Direct/Delayed Response Project: Definition of soil-sampling classes and selection of sampling sites for the Northeast

    SciTech Connect

    Lee, J.J.; Marmorek, D.R.; Thornton, K.W.; Stevens, D.L.; Lammers, D.A.

    1989-04-01

    The Direct/Delayed Response Project (DDRP) was designed and implemented to estimate the number of lakes and streams that might become acidic in three regions due to current or altered levels of acidic deposition. As part of DDRP, 145 watersheds in the northeast US were mapped at 1:24,000 for soils, vegetation, depth to bedrock, and bedrock geology. About 600 soils were identified during mapping. These were grouped into 38 soil-sampling classes. Each of these was sampled about 8 times across the region, so that regional means and standard deviations of soil properties could be computed for each class. The regional soil data will be used with the soil maps to estimate soil properties for each watershed. The watershed estimates will be used in the array of DDRP models to estimate future effects of acidic deposition on lakes in the northeast. The sampling classes were developed at a workshop held in Corvallis, Oregon July 16-18, 1985. This report documents the process and decisions of the workshop.

  13. The Viking X ray fluorescence experiment - Sampling strategies and laboratory simulations. [Mars soil sampling

    NASA Technical Reports Server (NTRS)

    Baird, A. K.; Castro, A. J.; Clark, B. C.; Toulmin, P., III; Rose, H., Jr.; Keil, K.; Gooding, J. L.

    1977-01-01

    Ten samples of Mars regolith material (six on Viking Lander 1 and four on Viking Lander 2) have been delivered to the X ray fluorescence spectrometers as of March 31, 1977. An additional six samples at least are planned for acquisition in the remaining Extended Mission (to January 1979) for each lander. All samples acquired are Martian fines from the near surface (less than 6-cm depth) of the landing sites except the latest on Viking Lander 1, which is fine material from the bottom of a trench dug to a depth of 25 cm. Several attempts on each lander to acquire fresh rock material (in pebble sizes) for analysis have yielded only cemented surface crustal material (duricrust). Laboratory simulation and experimentation are required both for mission planning of sampling and for interpretation of data returned from Mars. This paper is concerned with the rationale for sample site selections, surface sampler operations, and the supportive laboratory studies needed to interpret X ray results from Mars.

  14. Cometabolic mineralization of benzo[a]pyrene caused by hydrocarbon additions to soil

    SciTech Connect

    Kanaly, R.A.; Bartha, R.

    1999-10-01

    The mineralization of [7-{sup 14}C]benzo[a]pyrene (BaP) in soil was investigated in response to additions of individual hydrocarbons, defined hydrocarbon mixtures, crude oil, and crude oil fractions. Neither substantial BaP mineralization nor enrichment of BaP degraders occurred in BaP-spiked soil in the absence of a suitable hydrocarbon supplement. Crude oil, the saturated and aromatic class components of crude oil, the distillates heating oil, jet fuel, and diesel fuel supported up to 60% mineralization of 80 {micro}g [7-{sup 14}C]BaP per gram of soil in 40 d. Neither single hydrocarbons nor defined hydrocarbon mixtures containing normal and branched alkanes, alicyclics, and aromatics supported comparable BaP mineralization. Evolution of {sup 14}CO{sub 2} occurred after lag periods characteristic to specific petroleum products and their concentrations. Time required for microbial proliferation, hydrocarbon toxicity, and competitive inhibition might have contributed to these lag periods, but the complete inhibition of BaP mineralization by diesel-fuel vapors pointed to a dominant role of competitive inhibition. A lack of radiocarbon incorporation into soil biomass from [7-{sup 14}C]BaP indicated that at least the initial steps of BaP biodegradation in soil were cometabolic in nature. Suitable hydrocarbon mixtures not only supported BaP mineralization by serving as primary substrates, but also enhanced BaP bioavailability by dissolving this hydrophobic solid.

  15. Perfluoroalkyl carboxylic acids with up to 22 carbon atoms in snow and soil samples from a ski area.

    PubMed

    Plassmann, Merle M; Berger, Urs

    2013-05-01

    The use of fluorinated ski waxes as a direct input route of perfluoroalkyl carboxylic acids (PFCAs) to the environment was investigated. PFCA homologues with 6-22 carbon atoms (C6-22 PFCAs) were detected in fluorinated ski waxes and their raw materials by liquid chromatography coupled to tandem mass spectrometry. Snow and soil samples from a ski area in Sweden were taken after a skiing competition and after snowmelt, respectively. In both snow and soil samples C6-22 PFCAs were detected, representing the first report of PFCAs with up to 22 carbon atoms in environmental samples. Single analyte concentrations in snow (analyzed as melt water) and soil ranged up to 0.8μgL(-1) and 5ngg(-1) dry weight, respectively. ∑PFCA concentrations in snow and soil decreased from the start to the finish of the ski trail. Distinct differences in PFCA patterns between snow (prevalence of C14-20 PFCAs) and soil samples (C6-14 PFCAs dominating) were observed. Additionally, a PFCA pattern change from the start to about two third of the distance of the ski trail was found both for snow and soil, with a larger fraction of longer chain homologues present in samples from the start. These observations are probably a result of differences in PFCA homologue patterns present in different types of waxes. The calculated PFCA input from snow affected by the skiing competition was smaller than the PFCA inventory in soil for all chain lengths and markedly smaller for C6-15 PFCAs, presenting evidence for long-term accumulation in soil.

  16. Drilling power consumption and soil conveying volume performances of lunar sampling auger

    NASA Astrophysics Data System (ADS)

    Tian, Ye; Tang, Dewei; Deng, Zongquan; Jiang, Shengyuan; Quan, Qiquan

    2015-05-01

    The sampling auger used in lunar sampling and return mission is to transmit power and convey soil, and its performance is the key factor of the whole mission. However, there is currently a lack of the optimization research on soil conveying volume and power consumption models in auger structure design. To provide the drilled object, the simulation lunar soil, whose physical and mechanical property is the same as the real soil, is made by reducing soil void ratio. The models are formulated to analyze the influence of auger structure parameters on power consumption and soil conveying volume. To obtain the optimized structure parameters of auger, the multi-objective optimization functions of the maximum soil conveying volume and minimum power consumption are developed. To verify the correctness of the models, the performances of different augers drilling simulation soil are tested. The test results demonstrate that the power consumption of optimized auger is the lowest both in theory and test, and the experimental results of soil conveying volume are in agreement with theoretical analysis. Consequently, a new method for designing a lunar sampling auger is proposed which includes the models of soil conveying volume and transportation power consumption, the optimization of structure parameters and the comparison tests. This method provides a reference for sampling auger designing of the Chinese Lunar Sample Mission.

  17. 137Cs re-sampling as a method for soil erosion assessment in Alpine grasslands

    NASA Astrophysics Data System (ADS)

    Arata, Laura; Meusburger, Katrin; Bissig, Nicole; Mabit, Lionel; Alewell, Christine

    2014-05-01

    Over the past decades, radioactive fallout 137Cs has been used as a tracer to provide information on soil erosion and sedimentation rates. However, the method may produce relatively large uncertainties in Alpine grasslands. The latter difficulties are caused by a combination of (i) the heterogeneous distribution of atmospheric 137Cs Chernobyl fallout, (ii) the partly snow covered ground in Alpine areas during the fallout event in April 1986, which results in inhomogeneous 137Cs distribution during snow melt and (iii) uncertainties in finding undisturbed references sites in the geomorphological and anthropogenic highly active slopes of the Alps. To overcome these difficulties, our aim is to replace the classical 137Cs approach, where an undisturbed reference site is compared to erosional sites, with a re-sampling approach, where we re-sample sites which have already been measured for 137Cs inventories in the past. Thus, we use temporal instead of spatial reference. The study area is located in the Central Swiss Alps in the Urseren Valley. Potential erosional sites have been sampled in 2007 and re-sampled in 2012. Two different grassland types were investigated: hayfield (2 sites) and pasture without dwarf shrubs (3 sites). For each site, 4 to 9 sampling points have been defined, and at each point two soil samples have been collected. To reduce the random error, the two soil samples were bulked prior to gamma-analysis. 137Cs inventories of the two sampling years were calculated and used to assess recent soil erosion in the experimental sites. Our results show that within the 5 years measurable soil erosion and deposition processes have occurred within the sites, as indicated by the relevant difference between the 137Cs inventories of 2007 and 2012. 64% of the sites exhibit a decrease in 137Cs inventories, 20% of the sites an increase, and the remaining 16% no significant difference. In particular, hayfield sites have been affected by erosion processes, mostly due to

  18. Preliminary examination of lunar samples. [characteristics of rocks, soils, and subsurface samples returned by Apollo 17 flight

    NASA Technical Reports Server (NTRS)

    1973-01-01

    An analysis of the lunar samples returned by Apollo 17 was conducted to determine the petrographic characteristics. A table listing all the rocks returned by Apollo 17 by sample number, weight, and rock type is presented. Photographs of lunar samples are included to show the variety of rocks returned. Lunar soils were collected to aid in characterizing the four major photogeologic units determined by preflight studies. Tables are developed to show grain size and grain type for the lunar soils. Radiographs of the drive tubes are interpreted to show the formations existing at various depths below the lunar surface.

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

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

  20. Do microbes destabilise old soil organic matter after fresh substrate addition?

    NASA Astrophysics Data System (ADS)

    Derrien, Delphine; Plain, Caroline; Courty, Pierre-Emmanuel; Gelhaye, Louisette; Moerdijk-Poortvliet, Tanja; Thomas, Fabien; Versini, Antoine; Zeller, Bernd; Koutika, Lydie-Stella; Boschker, Eric; Epron, Daniel

    2014-05-01

    The input of fresh organic matter to soil may stimulate microbial activity and alter soil carbon storage by enhancing mineralization of native soil organic carbon (SOC). Assessing the age of sequestered SOC utilised by stimulated microbes is a major challenge as the destabilisation of old SOC would be much more damageable for the overall carbon budget than the mobilization of recent SOC. Here, we investigated the microbial populations sequentially activated after the addition of a labile substrate. We questioned wether they have distinct metabolic potential and we characterised the age of the native SOC they mineralised. We used C3-C4 soils from Congolese Eucalyptus plantations that were previously under savannah: old (C4) and recent (C3) SOC exhibited different delta 13C. Soils were amended with glucose and incubated for one week. To partition respiration sources, the delta 13C of CO2 was continuously recorded using a tuneable diode laser spectrometer (TDLS). To characterise active microbial populations, this was combined with phospholipids fatty acids (PLFA) analyses and potential metabolic activities measurements after two and seven days of incubation. A peak of glucose mineralization occurred after 17 hours of incubation. After the peak of glucose consumption, over-mineralization of native SOC occurred for some days, first affecting the recent C3 SOC, and later the old C4 SOC. Before this peak, some decomposer populations with a strong feeding preference for recent SOC were triggered by glucose addition. They were likely responsible for glucose consumption but also for the subsequent enhanced mineralization of recent C3 SOC. They were then out-competed by slower communities preferentially utilising the old C4 SOC and displaying a high potential for degrading P- and N- containing substrates. As nitrogen enrichment of old soil organic matter is a general feature, we postulated that nitrogen exhaustion in the poor soil solution was responsible for the succession

  1. Effects of atmospheric precipitation additions on phytoplankton photosynthesis in Lake Michigan water samples

    SciTech Connect

    Parker, J.I.; Tisue, G.T.; Kennedy, C.W.; Seils, C.A.

    1981-01-01

    The effects of incremental additions (0.1 to 50% v/v) of atmospheric precipitation on phytoplankton photosynthesis (/sup 14/C uptake) were tested in Lake Michigan water samples. Wet deposition was used in experiments I, III, and IV, and a melted snow core was used in experiment II. Additions of precipitation significantly reduced photosynthesis in the first three experiments, starting at about the 5 to 15% treatment level. No significant difference occurred in experiment IV, but photosynthesis was greater than in the control samples and this precipitation sample appeared to stimulate primary productivity. Soluble reactive phosphate, nitrate, and ammonia levels in the precipitation samples exceeded the lake water averages by factors of 10, 2, and 50, respectively. Silicon levels in precipitation reduced pH very little and no consistent relationship was observed with reduced photosynthesis. Alkalinity was greatly reduced in the treated samples and special precautions were required in ce, Ti, Be, Co, Cu, Mo, Ni, P,f the Pd crystals of about 30 A. Possible mechanisms are discussed for isotope exchange in CO molecules in these catalysts and for the promoting effect of Pd on the activity of CuO.

  2. Effects of zinc addition to a copper-contaminated vineyard soil on sorption of Zn by soil and plant physiological responses.

    PubMed

    Tiecher, Tadeu L; Ceretta, Carlos A; Tiecher, Tales; Ferreira, Paulo A A; Nicoloso, Fernando T; Soriani, Hilda H; Rossato, Liana V; Mimmo, Tanja; Cesco, Stefano; Lourenzi, Cledimar R; Giachini, Admir J; Brunetto, Gustavo

    2016-07-01

    The occurrence of high levels of Cu in vineyard soils is often the result of intensive use of fungicides for the preventive control of foliar diseases and can cause toxicity to plants. Nowadays many grape growers in Southern Brazil have replaced Cu-based with Zn-based products. The aim of the study was to evaluate whether the increase in Zn concentration in a soil with high Cu contents can interfere with the dynamics of these elements, and if this increase in Zn may cause toxicity to maize (Zea mays L.). Soil samples were collected in two areas, one in a vineyard with more than 30 years of cultivation and high concentration of Cu and the other on a natural grassland area adjacent to the vineyard. Different doses of Cu and Zn were added to the soil, and the adsorption isotherms were built following the Langmuir's model. In a second experiment, the vineyard soil was spiked with different Zn concentrations (0, 30, 60, 90, 180, and 270mg Zn kg(-1)) in 3kg pots where maize was grown in a greenhouse for 35 days. When Cu and Zn were added together, there was a reduction in the quantities adsorbed, especially for Zn. Zn addition decreased the total plant dry matter and specific leaf mass. Furthermore, with the increase in the activity of catalase, an activation of the antioxidant system was observed. However, the system was not sufficiently effective to reverse the stress levels imposed on soil, especially in plants grown in the highest doses of Zn. At doses higher than 90Znmgkg(-1) in the Cu-contaminated vineyard soil, maize plants were no longer able to activate the protection mechanism and suffered from metal stress, resulting in suppressed dry matter yields due to impaired functioning of the photosynthetic apparatus and changes in the enzymatic activity of plants. Replacement of Cu- by Zn-based fungicides to avoid Cu toxicity has resulted in soil vineyards contaminated with these metals and damaging of plant photosynthetic apparatus and enzyme activity. PMID:27011111

  3. Short and mid-term effects of different biochar additions on soil GHG fluxes

    NASA Astrophysics Data System (ADS)

    Maier, Regine; Soja, Gerhard; Friesl-Hanl, Wolfgang; Dunst, Gerald; Kitzler, Barbara

    2015-04-01

    The application of biochar (BC) to soils may have a positive influence on physico-chemical soil properties and the mitigation of greenhouse gas (GHG) emissions. Furthermore, biochar contributes to a long-term soil carbon sequestration. The aim of this study is to explore short and mid-term effects (one day up to six months) of different BC-compost applications on soil GHG emissions, particularly CO2, CH4, N2O and NOx. In addition, compounds of the nitrogen cycle like NH4+, NO3- and the microbial biomass nitrogen (Nmic) were measured. For this purpose a field experiment in Kaindorf (Styria/Austria, gleyic Cambisol, loamy, 376 m.a.s.l.) with 16 plots and four different treatments was conducted. K = no BC-compost mixture but fertilized (NH4SO4) corresponding to T3 in 2013; T1 = 1 % BC-compost mixture, no addition of N in 2013 and 2014; T2 = 0.5 % BC-compost mixture, + 175 kg N ha-1 in 2013 and 2014; T3 = 1% BC-compost mixture, + 350 kg N ha-1 in 2013. Nitrogen was added as (NH4)2SO4 directly to the freshly produced biochar before mixing it with compost. Greenhouse gas fluxes (CO2, CH4, N2O) were measured monthly from closed chambers in the field over a period of six months, starting 30 days before BC application and ended shortly before harvesting in September. For the analysis of nitric oxide (NO) fluxes intact soil cylinders were taken from each plot and incubated at the laboratory at ambient air temperature. Mineral N contents were measured by the extraction with KCl-solution and the microbial biomass with chloroform-fumigation extraction (CFE). Biochar application to our agricultural soil showed no reduction potential of NO emissions, but N2O fluxes were significantly lower at T1 and T3 compared to treatment K. Gaseous N fluxes of the pure BC-compost mixture and the additional N fertilization with (NH4)2SO4 led to enormous gaseous N losses in form of N2O and NO. However, after application to the soil, fluxes were only higher for a short time period. We suggest

  4. Short-Term Responses of Soil Respiration and C-Cycle Enzyme Activities to Additions of Biochar and Urea in a Calcareous Soil.

    PubMed

    Song, Dali; Xi, Xiangyin; Huang, Shaomin; Liang, Guoqing; Sun, Jingwen; Zhou, Wei; Wang, Xiubin

    2016-01-01

    Biochar (BC) addition to soil is a proposed strategy to enhance soil fertility and crop productivity. However, there is limited knowledge regarding responses of soil respiration and C-cycle enzyme activities to BC and nitrogen (N) additions in a calcareous soil. A 56-day incubation experiment was conducted to investigate the combined effects of BC addition rates (0, 0.5, 1.0, 2.5 and 5.0% by mass) and urea (U) application on soil nutrients, soil respiration and C-cycle enzyme activities in a calcareous soil in the North China Plain. Our results showed soil pH values in both U-only and U plus BC treatments significantly decreased within the first 14 days and then stabilized, and CO2emission rate in all U plus BC soils decreased exponentially, while there was no significant difference in the contents of soil total organic carbon (TOC), dissolved organic carbon (DOC), total nitrogen (TN), and C/N ratio in each treatment over time. At each incubation time, soil pH, electrical conductivity (EC), TOC, TN, C/N ratio, DOC and cumulative CO2 emission significantly increased with increasing BC addition rate, while soil potential activities of the four hydrolytic enzymes increased first and then decreased with increasing BC addition rate, with the largest values in the U + 1.0%BC treatment. However, phenol oxidase activity in all U plus BC soils showed a decreasing trend with the increase of BC addition rate. Our results suggest that U plus BC application at a rate of 1% promotes increases in hydrolytic enzymes, does not highly increase C/N and C mineralization, and can improve in soil fertility. PMID:27589265

  5. Short-Term Responses of Soil Respiration and C-Cycle Enzyme Activities to Additions of Biochar and Urea in a Calcareous Soil

    PubMed Central

    Song, Dali; Xi, Xiangyin; Huang, Shaomin; Liang, Guoqing; Sun, Jingwen; Zhou, Wei; Wang, Xiubin

    2016-01-01

    Biochar (BC) addition to soil is a proposed strategy to enhance soil fertility and crop productivity. However, there is limited knowledge regarding responses of soil respiration and C-cycle enzyme activities to BC and nitrogen (N) additions in a calcareous soil. A 56-day incubation experiment was conducted to investigate the combined effects of BC addition rates (0, 0.5, 1.0, 2.5 and 5.0% by mass) and urea (U) application on soil nutrients, soil respiration and C-cycle enzyme activities in a calcareous soil in the North China Plain. Our results showed soil pH values in both U-only and U plus BC treatments significantly decreased within the first 14 days and then stabilized, and CO2emission rate in all U plus BC soils decreased exponentially, while there was no significant difference in the contents of soil total organic carbon (TOC), dissolved organic carbon (DOC), total nitrogen (TN), and C/N ratio in each treatment over time. At each incubation time, soil pH, electrical conductivity (EC), TOC, TN, C/N ratio, DOC and cumulative CO2 emission significantly increased with increasing BC addition rate, while soil potential activities of the four hydrolytic enzymes increased first and then decreased with increasing BC addition rate, with the largest values in the U + 1.0%BC treatment. However, phenol oxidase activity in all U plus BC soils showed a decreasing trend with the increase of BC addition rate. Our results suggest that U plus BC application at a rate of 1% promotes increases in hydrolytic enzymes, does not highly increase C/N and C mineralization, and can improve in soil fertility. PMID:27589265

  6. Short-Term Responses of Soil Respiration and C-Cycle Enzyme Activities to Additions of Biochar and Urea in a Calcareous Soil.

    PubMed

    Song, Dali; Xi, Xiangyin; Huang, Shaomin; Liang, Guoqing; Sun, Jingwen; Zhou, Wei; Wang, Xiubin

    2016-01-01

    Biochar (BC) addition to soil is a proposed strategy to enhance soil fertility and crop productivity. However, there is limited knowledge regarding responses of soil respiration and C-cycle enzyme activities to BC and nitrogen (N) additions in a calcareous soil. A 56-day incubation experiment was conducted to investigate the combined effects of BC addition rates (0, 0.5, 1.0, 2.5 and 5.0% by mass) and urea (U) application on soil nutrients, soil respiration and C-cycle enzyme activities in a calcareous soil in the North China Plain. Our results showed soil pH values in both U-only and U plus BC treatments significantly decreased within the first 14 days and then stabilized, and CO2emission rate in all U plus BC soils decreased exponentially, while there was no significant difference in the contents of soil total organic carbon (TOC), dissolved organic carbon (DOC), total nitrogen (TN), and C/N ratio in each treatment over time. At each incubation time, soil pH, electrical conductivity (EC), TOC, TN, C/N ratio, DOC and cumulative CO2 emission significantly increased with increasing BC addition rate, while soil potential activities of the four hydrolytic enzymes increased first and then decreased with increasing BC addition rate, with the largest values in the U + 1.0%BC treatment. However, phenol oxidase activity in all U plus BC soils showed a decreasing trend with the increase of BC addition rate. Our results suggest that U plus BC application at a rate of 1% promotes increases in hydrolytic enzymes, does not highly increase C/N and C mineralization, and can improve in soil fertility.

  7. Sampling errors associated with soil composites used to estimate mean Ra-226 concentrations at an UMTRA remedial-action site

    SciTech Connect

    Gilbert, R.O.; Baker, K.R.; Nelson, R.A.; Miller, R.H.; Miller, M.L.

    1987-07-01

    The decision whether to take additional remedial action (removal of soil) from regions contaminated by uranium mill tailings involves collecting 20 plugs of soil from each 10-m by 10-m plot in the region and analyzing a 500-g portion of the mixed soil for /sup 226/Ra. A soil sampling study was conducted in the windblown mill-tailings flood plain area at Shiprock, New Mexico, to evaluate whether reducing the number of soil plugs to 9 would have any appreciable impact on remedial-action decisions. The results of the Shiprock study are described and used in this paper to develop a simple model of the standard deviation of /sup 226/Ra measurements on composite samples formed from 21 or fewer plugs. This model is used to predict as a function of the number of soil plugs per composite, the percent accuracy with which the mean /sup 226/Ra concentration in surface soil can be estimated, and the probability of making incorrect remedial action decisions on the basis of statistical tests. 8 refs., 15 figs., 9 tabs.

  8. Additive non-uniform random sampling in superimposed fiber Bragg grating strain gauge

    NASA Astrophysics Data System (ADS)

    Ma, Y. C.; Liu, H. Y.; Yan, S. B.; Yang, Y. H.; Yang, M. W.; Li, J. M.; Tang, J.

    2013-05-01

    This paper demonstrates an additive non-uniform random sampling and interrogation method for dynamic and/or static strain gauge using a reflection spectrum from two superimposed fiber Bragg gratings (FBGs). The superimposed FBGs are designed to generate non-equidistant space of a sensing pulse train in the time domain during dynamic strain gauge. By combining centroid finding with smooth filtering methods, both the interrogation speed and accuracy are improved. A 1.9 kHz dynamic strain is measured by generating an additive non-uniform randomly distributed 2 kHz optical sensing pulse train from a mean 500 Hz triangular periodically changing scanning frequency.

  9. Rapid Recovery of Cyanobacterial Pigments in Desiccated Biological Soil Crusts following Addition of Water

    PubMed Central

    Abed, Raeid M. M.; Polerecky, Lubos; Al-Habsi, Amal; Oetjen, Janina; Strous, Marc; de Beer, Dirk

    2014-01-01

    We examined soil surface colour change to green and hydrotaxis following addition of water to biological soil crusts using pigment extraction, hyperspectral imaging, microsensors and 13C labeling experiments coupled to matrix-assisted laser desorption and ionization time of flight-mass spectrometry (MALD-TOF MS). The topsoil colour turned green in less than 5 minutes following water addition. The concentrations of chlorophyll a (Chl a), scytonemin and echinenon rapidly increased in the top <1 mm layer while in the deeper layer, their concentrations remained low. Hyperspectral imaging showed that, in both wet and dehydrated crusts, cyanobacteria formed a layer at a depth of 0.2–0.4 mm and this layer did not move upward after wetting. 13C labeling experiments and MALDI TOF analysis showed that Chl a was already present in the desiccated crusts and de novo synthesis of this molecule started only after 2 days of wetting due to growth of cyanobacteria. Microsensor measurements showed that photosynthetic activity increased concomitantly with the increase of Chl a, and reached a maximum net rate of 92 µmol m−2 h−1 approximately 2 hours after wetting. We conclude that the colour change of soil crusts to green upon water addition was not due to hydrotaxis but rather to the quick recovery and reassembly of pigments. Cyanobacteria in crusts can maintain their photosynthetic apparatus intact even under prolonged periods of desiccation with the ability to resume their photosynthetic activities within minutes after wetting. PMID:25375172

  10. In situ weathering vs eolian additions to soils: A proposed solution from lava tubes and cumulic soils, Owens Valley, Calif

    SciTech Connect

    Lafarge, D.W.; Burke, R.M. . Dept. of Geology)

    1993-04-01

    Natural dust traps in the form of open conduits to lava tubes, collapsed lava tubes, cinder cone depressions, and range-front half grabens create favorable environments for the accumulation of eolian materials through extended periods of geologic time. The radiometrically dated basalt flows in the Big Pine Lava Field, CA provide minimum and maximum constraining dates for accumulation rates of such eolian materials, which are also added, at least partially, to regional soils developed on moraines and alluvial fans. 1.2 meters of well sorted silts to fine sands are located within a lava tube formed in a flow emanating from the northern cone of the Stooges Range along the range front of the Inyo Mountains. This non-basaltic material records a minimum eolian accumulation rate of 4.8 mm/ka, whereas a somewhat thicker section in the subaerially exposed collapsed portion of the tube system suggests an accumulation rate of 8.0 mm/ka. Across Owens Valley along the Sierra Nevada range front, a cumulic soil described to a depth of 363+ cm is formed in a geomorphically youthful half graben near Crater Mountain (CM). This site records a bimodal particle size distribution of eolian silts and coarse sands, with locally derived very coarse sands and fine pebble gravels from juxtaposed granitic bedrock. Two plausible explanations for the cumulic, bimodal nature of the soil, with accompanying clay bulges are: (1) episodic sources for eolian dust induced by desiccation of pluvial Owens Lake, which would be in phase with Pleistocene climatic changes; or (2) continual input of the eolian component with episodic additions of the coarse-grained granitic materials brought about by periods of tectonism along the Sierra Nevada range front fault, thus not related to paleoclimate. Prevailing southerly winds suggested for times of peak dust availability, and the model of soil forming intervals proposed by Chadwick and Davis (1990) favor the first of these two explanations for the CM.

  11. On-site spectrophotometric determination of antimony in water, soil and dust samples of Central India.

    PubMed

    Shrivas, Kamlesh; Agrawal, Kavita; Harmukh, Neetu

    2008-06-30

    A new, selective and sensitive on-site spectrophotometric method for the determination of antimony at trace level in water, soil and dust samples of Central India has been demonstrated. It is based on the color reaction of Sb(III) with I(-) ions in the presence of a cationic surfactant cetylpyridinium chloride (CPC) in acidic media, and subsequent extraction of the complex with N-phenylbenzimidoylthiourea (PBITU) into chloroform to give a yellow colored complex. The value of apparent molar absorptivity of the complex in the terms of Sb is (7.84) x 10(4)l mol(-1)cm(-1) at 440 nm. The detection limit of the method is 5 ng ml(-1). In addition, the present method is free from interferences of all metal ions that are associated during the determination of antimony in environmental samples.

  12. On-site spectrophotometric determination of antimony in water, soil and dust samples of Central India.

    PubMed

    Shrivas, Kamlesh; Agrawal, Kavita; Harmukh, Neetu

    2008-06-30

    A new, selective and sensitive on-site spectrophotometric method for the determination of antimony at trace level in water, soil and dust samples of Central India has been demonstrated. It is based on the color reaction of Sb(III) with I(-) ions in the presence of a cationic surfactant cetylpyridinium chloride (CPC) in acidic media, and subsequent extraction of the complex with N-phenylbenzimidoylthiourea (PBITU) into chloroform to give a yellow colored complex. The value of apparent molar absorptivity of the complex in the terms of Sb is (7.84) x 10(4)l mol(-1)cm(-1) at 440 nm. The detection limit of the method is 5 ng ml(-1). In addition, the present method is free from interferences of all metal ions that are associated during the determination of antimony in environmental samples. PMID:18155833

  13. Micro-PIXE evaluation of radioactive cesium transfer in contaminated soil samples

    NASA Astrophysics Data System (ADS)

    Fujishiro, F.; Ishii, K.; Matsuyama, S.; Arai, H.; Ishizaki, A.; Osada, N.; Sugai, H.; Kusano, K.; Nozawa, Y.; Yamauchi, S.; Karahashi, M.; Oshikawa, S.; Kikuchi, K.; Koshio, S.; Watanabe, K.; Suzuki, Y.

    2014-01-01

    Micro-PIXE analysis has been performed on two soil samples with high cesium activity concentrations. These soil samples were contaminated by fallout from the accident at Fukushima Daiichi Nuclear Power Plant. One exhibits a radioactive cesium transfer of ˜0.01, and the other shows a radioactive cesium transfer of less than 0.001, even though both samples have high cesium activity concentrations exceeding 10,000 Bq/kg. X-ray spectra and elemental images of the soil samples revealed the presence of chlorine, which can react with cesium to produce an inorganic soluble compound, and phosphorus-containing cesium-capturable organic compounds.

  14. Greenhouse gas emissions from sub-tropical agricultural soils after addition of organic by-products.

    PubMed

    Nguyen, Dai H; Biala, Johannes; Grace, Peter R; Scheer, Clemens; Rowlings, David W

    2014-01-01

    As the cost of mineral fertilisers increases globally, organic soil amendments (OAs) from agricultural sources are increasingly being used as substitutes for nitrogen. However, the impact of OAs on the production of greenhouse gases (CO2 and N2O) is not well understood. A 60-day laboratory incubation experiment was conducted to investigate the impacts of applying OAs (equivalent to 296 kg N ha(-1) on average) on N2O and CO2 emissions and soil properties of clay and sandy loam soils from sugar cane production. The experiment included 6 treatments, one being an un-amended (UN) control with addition of five OAs being raw mill mud (MM), composted mill mud (CM), high N compost (HC), rice husk biochar (RB), and raw mill mud plus rice husk biochar (MB). These OAs were incubated at 60, 75 and 90% water-filled pore space (WFPS) at 25°C with urea (equivalent to 200 kg N ha(-1)) added to the soils thirty days after the incubation commenced. Results showed WFPS did not influence CO2 emissions over the 60 days but the magnitude of emissions as a proportion of C applied was RB < CM < MB < HC < MM. Nitrous oxide emissions were significantly less in the clay soil compared to the sandy loam at all WFPS, and could be ranked RB < MB < MM < CM < UN < HC. These results led to linear models being developed to predict CO2 and N2O emissions as a function of the dry matter and C/N ratio of the OAs, WFPS, and the soil CEC. Application of RB reduced N2O emissions by as much as 42-64% depending on WFPS. The reductions in both CO2 and N2O emissions after application of RB were due to a reduced bioavailability of C and not immobilisation of N. These findings show that the effect of OAs on soil GHG emissions can vary substantially depending on their chemical properties. OAs with a high availability of labile C and N can lead to elevated emissions of CO2 and N2O, while rice husk biochar showed potential in reducing overall soil GHG emissions.

  15. Greenhouse gas emissions from sub-tropical agricultural soils after addition of organic by-products.

    PubMed

    Nguyen, Dai H; Biala, Johannes; Grace, Peter R; Scheer, Clemens; Rowlings, David W

    2014-01-01

    As the cost of mineral fertilisers increases globally, organic soil amendments (OAs) from agricultural sources are increasingly being used as substitutes for nitrogen. However, the impact of OAs on the production of greenhouse gases (CO2 and N2O) is not well understood. A 60-day laboratory incubation experiment was conducted to investigate the impacts of applying OAs (equivalent to 296 kg N ha(-1) on average) on N2O and CO2 emissions and soil properties of clay and sandy loam soils from sugar cane production. The experiment included 6 treatments, one being an un-amended (UN) control with addition of five OAs being raw mill mud (MM), composted mill mud (CM), high N compost (HC), rice husk biochar (RB), and raw mill mud plus rice husk biochar (MB). These OAs were incubated at 60, 75 and 90% water-filled pore space (WFPS) at 25°C with urea (equivalent to 200 kg N ha(-1)) added to the soils thirty days after the incubation commenced. Results showed WFPS did not influence CO2 emissions over the 60 days but the magnitude of emissions as a proportion of C applied was RB < CM < MB < HC < MM. Nitrous oxide emissions were significantly less in the clay soil compared to the sandy loam at all WFPS, and could be ranked RB < MB < MM < CM < UN < HC. These results led to linear models being developed to predict CO2 and N2O emissions as a function of the dry matter and C/N ratio of the OAs, WFPS, and the soil CEC. Application of RB reduced N2O emissions by as much as 42-64% depending on WFPS. The reductions in both CO2 and N2O emissions after application of RB were due to a reduced bioavailability of C and not immobilisation of N. These findings show that the effect of OAs on soil GHG emissions can vary substantially depending on their chemical properties. OAs with a high availability of labile C and N can lead to elevated emissions of CO2 and N2O, while rice husk biochar showed potential in reducing overall soil GHG emissions. PMID

  16. Vigorous Mold Growth in Soils After Addition of Water-Insoluble Fatty Substances

    PubMed Central

    Krause, Frank P.; Lange, Willy

    1965-01-01

    Various water-insoluble fatty compounds, when added to soil in finely divided form, will support as high-caloric nutrients a visible, vigorous growth of the molds, Fusarium solani Mart., F. diversisporum Sherb., and F. equiseti. n-Paraffins and olefins are most effective, because the effect of additives is reduced to the extent that oxygen atoms are introduced into the molecule. n-Fatty alcohols support growth in soil almost as well as the paraffins; however, growth is reduced when branched-chain compounds are added as nutrients. Compounds that will support mold growth when added to air-dried soil as finely powdered solids will not do so when incorporated at temperatures above their melting point, but will produce dense growth when applied to wet soil in this form. Mold growth is correlated with degradation of fatty matter. The rate of degradation is controlled by the availability of water, oxygen, and the basic inorganic nutrients. Images Fig. 1 Fig. 2 PMID:14325872

  17. Use of mass spectrometry coupled with a solids insertion probe to prescreen soil samples for environmental samples

    SciTech Connect

    Check, C.E.; Bach, S.B.H.

    1995-12-31

    The contamination of air, water, and soils by a myriad of sources generates a large sample Currently, sample volume for hazardous constituent analyses is approximately half a million samples per year. The total analytical costs associated with this are astronomical. The analysis of these samples is vital in terms of assessing the types of contamination present and to what degree a site has been contaminated. The results of these analyses are very important for making an informed, knowledgeable decision as to the need for remediation and what type of remediation processes should be initiated based on site suitability vs non-action for the various sample sites. With an ever growing environmental consciousness in today`s society, the assessment and subsequent remediation of a site needs to be accomplished promptly despite the time constraints traditional methods place on such actions. In order to facilitate a rapid assessment, it is desirable to utilize instrumentation and equipment which afford the most information about a site allowing for optimization in environmental assessment while maintaining a realistic time schedule for the resulting remediation process. Because there are various types of environmental samples that can be taken at a site, different combinations of instrumentation and methods are required for assessing the level and type of contamination present whether it is in air, water, or soils. This study is limited to analyzing soil-like media that would normally fall under EPA Method 8270 which is used to analyze solid waste matrices, soils, and groundwater for semi-volatile organic compounds.

  18. Quantitative Field Testing Heterodera glycines from Metagenomic DNA Samples Isolated Directly from Soil under Agronomic Production

    PubMed Central

    Li, Yan; Lawrence, Gary W.; Lu, Shien; Balbalian, Clarissa; Klink, Vincent P.

    2014-01-01

    A quantitative PCR procedure targeting the Heterodera glycines ortholog of the Caenorhabditis elegans uncoordinated-78 gene was developed. The procedure estimated the quantity of H. glycines from metagenomic DNA samples isolated directly from field soil under agronomic production. The estimation of H. glycines quantity was determined in soil samples having other soil dwelling plant parasitic nematodes including Hoplolaimus, predatory nematodes including Mononchus, free-living nematodes and biomass. The methodology provides a framework for molecular diagnostics of nematodes from metagenomic DNA isolated directly from field soil. PMID:24587100

  19. Quantitative field testing Heterodera glycines from metagenomic DNA samples isolated directly from soil under agronomic production.

    PubMed

    Li, Yan; Lawrence, Gary W; Lu, Shien; Balbalian, Clarissa; Klink, Vincent P

    2014-01-01

    A quantitative PCR procedure targeting the Heterodera glycines ortholog of the Caenorhabditis elegans uncoordinated-78 gene was developed. The procedure estimated the quantity of H. glycines from metagenomic DNA samples isolated directly from field soil under agronomic production. The estimation of H. glycines quantity was determined in soil samples having other soil dwelling plant parasitic nematodes including Hoplolaimus, predatory nematodes including Mononchus, free-living nematodes and biomass. The methodology provides a framework for molecular diagnostics of nematodes from metagenomic DNA isolated directly from field soil.

  20. X-ray spectrometry and X-ray microtomography techniques for soil and geological samples analysis

    NASA Astrophysics Data System (ADS)

    Kubala-Kukuś, A.; Banaś, D.; Braziewicz, J.; Dziadowicz, M.; Kopeć, E.; Majewska, U.; Mazurek, M.; Pajek, M.; Sobisz, M.; Stabrawa, I.; Wudarczyk-Moćko, J.; Góźdź, S.

    2015-12-01

    A particular subject of X-ray fluorescence analysis is its application in studies of the multielemental sample of composition in a wide range of concentrations, samples with different matrices, also inhomogeneous ones and those characterized with different grain size. Typical examples of these kinds of samples are soil or geological samples for which XRF elemental analysis may be difficult due to XRF disturbing effects. In this paper the WDXRF technique was applied in elemental analysis concerning different soil and geological samples (therapeutic mud, floral soil, brown soil, sandy soil, calcium aluminum cement). The sample morphology was analyzed using X-ray microtomography technique. The paper discusses the differences between the composition of samples, the influence of procedures with respect to the preparation of samples as regards their morphology and, finally, a quantitative analysis. The results of the studies were statistically tested (one-way ANOVA and correlation coefficients). For lead concentration determination in samples of sandy soil and cement-like matrix, the WDXRF spectrometer calibration was performed. The elemental analysis of the samples was complemented with knowledge of chemical composition obtained by X-ray powder diffraction.

  1. Addition of a clay subsoil to a sandy top soil alters CO2 release and the interactions in residue mixtures.

    PubMed

    Shi, Andong; Marschner, Petra

    2013-11-01

    Addition of clay-rich subsoils to sandy top soils is an agricultural management option to increase water and nutrient retention and may also increase organic carbon sequestration by decreasing the decomposition rates. An incubation experiment was carried out in a loamy sand top soil mixed with a clay-rich subsoil (84% clay) at 0, 10 and 30% (w/w) amended with finely ground mature shoot residues of two native perennial grasses and annual barley individually or in 1:1 mixtures of two residues. Extractable C, microbial biomass C, available N and soil pH were analysed at days 0, 3, 14 and 28. Cumulative respiration after 28 days was highest with barley residue and lowest with Wallaby grass at all clay soil addition rates; 30% clay soil addition reduced cumulative respiration, especially with barley alone. In the mixture of native grasses and barley, the measured respiration was lower than expected at a clay soil addition rate of 10%. A synergistic effect (higher than expected cumulative respiration) was only found in mixture of Kangaroo grass and barley at a clay soil addition rate of 30%. Clay soil addition also decreased extractable C, available N and soil pH. The temporal change in microbial biomass C and available N in residue mixtures differed among clay addition rates. In the mixture of Wallaby grass and Kangaroo grass, microbial biomass C (MBC) decreased from day 0 to day 28 at clay soil addition rates of 0 and 10%, whereas at 30% clay MBC increased from day 0 to day 3 and then decreased. Our study shows that addition of a clay-rich subsoil to a loamy sand soil can increase C sequestration by reducing CO2 release and extractable C which are further modulated by the type of residues present individually or as mixtures.

  2. The Development of Mathematical Prediction Model to Predict Resilient Modulus for Natural Soil Stabilized by Pofa-Opc Additive for the Use in Unpaved Road Design

    NASA Astrophysics Data System (ADS)

    Gamil, Y. M. R.; Bakar, I. H.

    2016-07-01

    Resilient Modulus (Mr) is considered one of the most important parameters in the design of road structure. This paper describes the development of the mathematical model to predict resilient modulus of organic soil stabilized by the mix of Palm Oil Fuel Ash - Ordinary Portland Cement (POFA-OPC) soil stabilization additives. It aims to optimize the use of the use of POFA in soil stabilization. The optimization models enable to eliminate the arbitrary selection and its associated disadvantages in determination of the optimum additive proportion. The model was developed based on Scheffe regression theory. The mix proportions of the samples in the experiment were adopted from similar studies reported in the literature Twenty five samples were designed, prepared and then characterized for each mix proportion based on the MR in 28 days curing. The results are used to develop the mathematical prediction model. The model was statistically analyzed and verified for its adequacy and validity using F-test.

  3. Determining the relative importance of soil sample locations to predict risk of child lead exposure.

    PubMed

    Zahran, Sammy; Mielke, Howard W; McElmurry, Shawn P; Filippelli, Gabriel M; Laidlaw, Mark A S; Taylor, Mark P

    2013-10-01

    Soil lead in urban neighborhoods is a known predictor of child blood lead levels. In this paper, we address the question where one ought to concentrate soil sample collection efforts to efficiently predict children at-risk for soil Pb exposure. Two extensive data sets are combined, including 5467 surface soil samples collected from 286 census tracts, and geo-referenced blood Pb data for 55,551 children in metropolitan New Orleans, USA. Random intercept least squares, random intercept logistic, and quantile regression results indicate that soils collected within 1m adjacent to residential streets most reliably predict child blood Pb outcomes in child blood Pb levels. Regression decomposition results show that residential street soils account for 39.7% of between-neighborhood explained variation, followed by busy street soils (21.97%), open space soils (20.25%), and home foundation soils (18.71%). Just as the age of housing stock is used as a statistical shortcut for child risk of exposure to lead-based paint, our results indicate that one can shortcut the characterization of child risk of exposure to neighborhood soil Pb by concentrating sampling efforts within 1m and adjacent to residential and busy streets, while significantly reducing the total costs of collection and analysis. This efficiency gain can help advance proactive upstream, preventive methods of environmental Pb discovery.

  4. Increases in soil aggregation following phosphorus additions in a tropical premontane forest are not driven by root and arbuscular mycorrhizal fungal abundances

    NASA Astrophysics Data System (ADS)

    Camenzind, Tessa; Papathanasiou, Helena; Foerster, Antje; Dietrich, Karla; Hertel, Dietrich; Homeier, Juergen; Oelmann, Yvonne; Olsson, Pål Axel; Suárez, Juan; Rillig, Matthias

    2015-12-01

    Tropical ecosystems have an important role in global change scenarios, in part because they serve as a large terrestrial carbon pool. Carbon protection is mediated by soil aggregation processes, whereby biotic and abiotic factors influence the formation and stability of aggregates. Nutrient additions may affect soil structure indirectly by simultaneous shifts in biotic factors, mainly roots and fungal hyphae, but also via impacts on abiotic soil properties. Here, we tested the hypothesis that soil aggregation will be affected by nutrient additions primarily via changes in arbuscular mycorrhizal fungal (AMF) hyphae and root length in a pristine tropical forest system. Therefore, the percentage of water-stable macroaggregates (> 250µm) (WSA) and the soil mean weight diameter (MWD) was analyzed, as well as nutrient contents, pH, root length and AMF abundance. Phosphorus additions significantly increased the amount of WSA, which was consistent across two different sampling times. Despite a positive effect of phosphorus additions on extraradical AMF biomass, no relationship between WSA and extra-radical AMF nor roots was revealed by regression analyses, contrary to the proposed hypothesis. These findings emphasize the importance of analyzing soil structure in understudied tropical systems, since it might be affected by increasing nutrient deposition expected in the future.

  5. Consistent effects of canopy vs. understory nitrogen addition on the soil exchangeable cations and microbial community in two contrasting forests.

    PubMed

    Shi, Leilei; Zhang, Hongzhi; Liu, Tao; Zhang, Weixin; Shao, Yuanhu; Ha, Denglong; Li, Yuanqiu; Zhang, Chuangmao; Cai, Xi-an; Rao, Xingquan; Lin, Yongbiao; Zhou, Lixia; Zhao, Ping; Ye, Qing; Zou, Xiaoming; Fu, Shenglei

    2016-05-15

    Anthropogenic N deposition has been well documented to cause substantial impacts on the chemical and biological properties of forest soils. In most studies, however, atmospheric N deposition has been simulated by directly adding N to the forest floor. Such studies thus ignored the potentially significant effect of some key processes occurring in forest canopy (i.e., nitrogen retention) and may therefore have incorrectly assessed the effects of N deposition on soils. Here, we conducted an experiment that included both understory addition of N (UAN) and canopy addition of N (CAN) in two contrasting forests (temperate deciduous forest vs. subtropical evergreen forest). The goal was to determine whether the effects on soil exchangeable cations and microbial biomass differed between CAN and UAN. We found that N addition reduced pH, BS (base saturation) and exchangeable Ca and increased exchangeable Al significantly only at the temperate JGS site, and reduced the biomass of most soil microbial groups only at the subtropical SMT site. Except for soil exchangeable Mn, however, effects on soil chemical properties and soil microbial community did not significantly differ between CAN and UAN. Although biotic and abiotic soil characteristics differ significantly and the responses of both soil exchangeable cations and microbial biomass were different between the two study sites, we found no significant interactive effects between study site and N treatment approach on almost all soil properties involved in this study. In addition, N addition rate (25 vs. 50 kg N ha(-1) yr(-1)) did not show different effects on soil properties under both N addition approaches. These findings did not support previous prediction which expected that, by bypassing canopy effects (i.e., canopy retention and foliage fertilization), understory addition of N would overestimate the effects of N deposition on forest soil properties, at least for short time scale.

  6. Consistent effects of canopy vs. understory nitrogen addition on the soil exchangeable cations and microbial community in two contrasting forests.

    PubMed

    Shi, Leilei; Zhang, Hongzhi; Liu, Tao; Zhang, Weixin; Shao, Yuanhu; Ha, Denglong; Li, Yuanqiu; Zhang, Chuangmao; Cai, Xi-an; Rao, Xingquan; Lin, Yongbiao; Zhou, Lixia; Zhao, Ping; Ye, Qing; Zou, Xiaoming; Fu, Shenglei

    2016-05-15

    Anthropogenic N deposition has been well documented to cause substantial impacts on the chemical and biological properties of forest soils. In most studies, however, atmospheric N deposition has been simulated by directly adding N to the forest floor. Such studies thus ignored the potentially significant effect of some key processes occurring in forest canopy (i.e., nitrogen retention) and may therefore have incorrectly assessed the effects of N deposition on soils. Here, we conducted an experiment that included both understory addition of N (UAN) and canopy addition of N (CAN) in two contrasting forests (temperate deciduous forest vs. subtropical evergreen forest). The goal was to determine whether the effects on soil exchangeable cations and microbial biomass differed between CAN and UAN. We found that N addition reduced pH, BS (base saturation) and exchangeable Ca and increased exchangeable Al significantly only at the temperate JGS site, and reduced the biomass of most soil microbial groups only at the subtropical SMT site. Except for soil exchangeable Mn, however, effects on soil chemical properties and soil microbial community did not significantly differ between CAN and UAN. Although biotic and abiotic soil characteristics differ significantly and the responses of both soil exchangeable cations and microbial biomass were different between the two study sites, we found no significant interactive effects between study site and N treatment approach on almost all soil properties involved in this study. In addition, N addition rate (25 vs. 50 kg N ha(-1) yr(-1)) did not show different effects on soil properties under both N addition approaches. These findings did not support previous prediction which expected that, by bypassing canopy effects (i.e., canopy retention and foliage fertilization), understory addition of N would overestimate the effects of N deposition on forest soil properties, at least for short time scale. PMID:26930308

  7. EFFECT OF NITROGEN AND METAL ADDITIONS ON NITROGEN FIXATION ACTIVITY IN BIOLOGICAL SOIL CRUSTS

    NASA Astrophysics Data System (ADS)

    Alexander, K.; Lui, D.; Anbar, A. D.; Garcia-Pichel, F.; Hartnett, H. E.

    2009-12-01

    Biological soil crusts (BSCs) are diverse consortia of microorganisms that live in intimate association with soils in arid environments. Also called cryptogamic or microbiotic crusts, these communities can include cyanobacteria, algae, heterotrophic bacteria, fungi, lichens, and mosses. Together, these organisms provide many services to their surrounding ecosystems, including reduction of water runoff, promotion of water infiltration, and prevention of soil erosion. The cyanobacteria and algae also provide fixed carbon (C) to the soil through photosynthesis, and because atmospheric deposition of nitrogen (N) in arid environments is low, the major input of biologically available N comes from cyanobacteria capable of converting nitrogen gas (N2) to ammonium (NH4+). Biological soil crusts are easily destroyed by livestock grazing, motor vehicle travel, and many forms of recreational and agricultural land use. Loss of BSC cover can leave the soil vulnerable to intense erosion that can remove the nutrients necessary to sustain plant and animal life, thus accelerating the process of desertification. In order to preserve existing crusts and encourage the development of new crusts, it is crucial to understand the nutrient requirements of metabolism and growth in these microbial communities. This study investigated the affect of nitrogen and metal additions on N2-fixation activity in cyanobacterially-dominated crusts from the Colorado Plateau near Moab, Utah. Although N2-fixation has been studied in this system before, the affect of nutrient additions on N2-fixation activity has not been documented. The goal of this work was to understand how N and metal supplementation affects crust N metabolism. Three experiments were conducted to observe how N2-fixation activity changed with the addition of N, molybdenum (Mo), and vanadium (V). Molybdenum and vanadium were chosen because they are most commonly found at the active site of the enzyme nitrogenase, the molecule responsible

  8. Methane flux in non-wetland soils in response to nitrogen addition: a meta-analysis.

    PubMed

    Aronson, E L; Helliker, B R

    2010-11-01

    The controls on methane (CH4) flux into and out of soils are not well understood. Environmental variables including temperature, precipitation, and nitrogen (N) status can have strong effects on the magnitude and direction (e.g., uptake vs. release) of CH4 flux. To better understand the interactions between CH4-cycling microorganisms and N in the non-wetland soil system, a meta-analysis was performed on published literature comparing CH4 flux in N amended and matched control plots. An appropriate study index was developed for this purpose. It was found that smaller amounts of N tended to stimulate CH4 uptake while larger amounts tended to inhibit uptake by the soil. When all other variables were accounted for, the switch occurred at 100 kg N x ha(-1) x yr(-1). Managed land and land with a longer duration of fertilization showed greater inhibition of CH4 uptake with added N. These results support the hypotheses that large amounts of available N can inhibit methanotrophy, but also that methanotrophs in upland soils can be N limited in their consumption of CH4 from the atmosphere. There were interactions between other variables and N addition on the CH4 flux response: lower temperature and, to a lesser extent, higher precipitation magnified the inhibition of CH4 uptake due to N addition. Several mechanisms that may cause these trends are discussed, but none could be conclusively supported with this approach. Further controlled and in situ study should be undertaken to isolate the correct mechanism(s) responsible and to model upland CH4 flux. PMID:21141185

  9. Stabilization and Destabilization of Soil Carbon with Nitrogen Additions in Two Tropical Forests

    NASA Astrophysics Data System (ADS)

    Cusack, D. F.; Silver, W.; Torn, M.; McDowell, W. H.

    2008-12-01

    Nitrogen (N) deposition is known to effect carbon (C) cycling in temperate ecosystems, but less is known about the effects of added N in tropical forests, where N is not generally limiting to plant growth. We examined changes in soil C dynamics with N fertilization in two tropical forest types (lower elevation and montane) in the Luquillo Mountains, Puerto Rico. We hypothesized that increased N would accelerate the decomposition of labile C pools, while decreasing losses of more recalcitrant C compounds. We measured C and C:N in bulk soil C and C fractions (free light, occluded light, and heavy fractions) as measures of C content and chemical properties in fertilized and control plots. To address our hypotheses, we conducted several measures of microbial activity, including extracellular enzyme activities and respiration during a long-term soil incubation. We included measurements of 14C of CO2 respired during the soil incubation to determine whether added N changed the age of respired C. After 3.5 years of N fertilization, plots with added N had higher C content (42.3 ± 6.8 and 40.7 ± 4.7 g/cm2, lower elevation and montane respectively) than control plots (34.2 ± 5.9 and 34.3 ± 1.3 g/cm2) at 0 - 10 cm depth. While the labile fraction of C declined with added N as a proportion of total soil weight, the C concentration of the heavy fraction increased in fertilized plots (2.9 ± 0.3 and 4.0 ± 0.7%) relative to control plots (2.6 ± 0.4 and 2.8 ± 0.5 %), helping explain the increase in bulk soil C content. The soil incubation revealed changes in microbial respiration with added N, and a trend toward higher 14C of CO2 in fertilized plots for the lower elevation forest. Together, these results indicate that rates of C stabilization in the heavy fraction exceeded the increase in respiration of older C with N additions.

  10. 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.

  11. Radiochemical determination of 237NP in soil samples contaminated with weapon grade plutonium

    NASA Astrophysics Data System (ADS)

    Antón, M. P.; Espinosa, A.; Aragón, A.

    2006-01-01

    The Palomares terrestrial ecosystem (Spain) constitutes a natural laboratory to study transuranics. This scenario is partially contaminated with weapon-grade plutonium since the burnout and fragmentation of two thermonuclear bombs accidentally dropped in 1966. While performing radiometric measurements in the field, the possible presence of 237Np was observed through its 29 keV gamma emission. To accomplish a detailed characterization of the source term in the contaminated area using the isotopic ratios Pu-Am-Np, the radiochemical isolation and quantification by alpha spectrometry of 237Np was initiated. The selected radiochemical procedure involves separation of Np from Am, U and Pu with ionic resins, given that in soil samples from Palomares 239+240Pu levels are several orders of magnitude higher than 237Np. Then neptunium is isolated using TEVA organic resins. After electrodeposition, quantification is performed by alpha spectrometry. Different tests were done with blank solutions spiked with 236Pu and 237Np, solutions resulting from the total dissolution of radioactive particles and soil samples. Results indicate that the optimal sequential radionuclide separation order is Pu-Np, with decontamination percentages obtained with the ionic resins ranging from 98% to 100%. Also, the addition of NaNO2 has proved to be necessary, acting as a stabilizer of Pu-Np valences.

  12. Quantitative Field Testing Rotylenchulus reniformis DNA from Metagenomic Samples Isolated Directly from Soil

    PubMed Central

    Showmaker, Kurt; Lawrence, Gary W.; Lu, Shien; Balbalian, Clarissa; Klink, Vincent P.

    2011-01-01

    A quantitative PCR procedure targeting the β-tubulin gene determined the number of Rotylenchulus reniformis Linford & Oliveira 1940 in metagenomic DNA samples isolated from soil. Of note, this outcome was in the presence of other soil-dwelling plant parasitic nematodes including its sister genus Helicotylenchus Steiner, 1945. The methodology provides a framework for molecular diagnostics of nematodes from metagenomic DNA isolated directly from soil. PMID:22194958

  13. Carbon mineralisation and plant growth in soil amended with compost samples at different degrees of maturity.

    PubMed

    García-Gómez, Antonio; Bernal, María Pilar; Roig, Asunción

    2003-04-01

    The carbon and nitrogen mineralisation of a composting mixture of brewing yeast and lemon tree prunings was studied, at different degrees of stabilisation of this matrix, within an incubation experiment in soil. Meanwhile, a growth test in pots with ryegrass (Lolium perenne L.) was carried out using the selected soil and equal amounts of the composting mixture taken at different maturation steps, in order to evaluate the additions of these organic amendments in terms of fertilising value. Samples of the composting mixture, when poorly transformed through the biostabilisation process, showed high CO2-C releases in the soil, due to the microbial attack on easily degradable organic fractions still present in the mixture, with 24.7% mineralisation of the initial total organic carbon (TOC) after a 70 day incubation. On the other hand, mature compost was the most stable matrix, with only 5.4% of TOC mineralised after 70 days. Furthermore, amendments with the initial composting mixture led to negative net N-mineralisation during 56 days of incubation with soil. Only slight negative values of the net N-mineralisation were detected with fully stabilised compost. Nevertheless, pot experiments with ryegrass revealed that mature compost may promote N mineralisation to certain extents. Moreover, mature compost did not produce any phytotoxic effect, behaving as a slow-action organic fertiliser with N made available through a progressive mineralisation. Thus, the results gained through this study are a confirmation that the fertilising quality of a compost destined for agricultural uses is heavily affected by the complete exhaustion of the maturation reactions.

  14. Quantitative passive soil vapor sampling for VOCs--part 3: field experiments.

    PubMed

    McAlary, Todd; Groenevelt, Hester; Nicholson, Paul; Seethapathy, Suresh; Sacco, Paolo; Crump, Derrick; Tuday, Michael; Hayes, Heidi; Schumacher, Brian; Johnson, Paul; Górecki, Tadeusz; Rivera-Duarte, Ignacio

    2014-03-01

    Volatile organic compounds (VOCs) are commonly associated with contaminated land and may pose a risk to human health via subsurface vapor intrusion to indoor air. Soil vapor sampling is commonly used to assess the nature and extent of VOC contamination, but can be complicated because of the wide range of geologic material permeability and moisture content conditions that might be encountered, the wide variety of available sampling and analysis methods, and several potential causes of bias and variability, including leaks of atmospheric air, adsorption-desorption interactions, inconsistent sampling protocols and varying levels of experience among sampling personnel. Passive sampling onto adsorbent materials has been available as an alternative to conventional whole-gas sample collection for decades, but relationships between the mass sorbed with time and the soil vapor concentration have not been quantitatively established and the relative merits of various commercially available passive samplers for soil vapor concentration measurement is unknown. This paper presents the results of field experiments using several different passive samplers under a wide range of conditions. The results show that properly designed and deployed quantitative passive soil vapor samplers can be used to measure soil vapor concentrations with accuracy and precision comparable to conventional active soil vapor sampling (relative concentrations within a factor of 2 and RSD comparable to active sampling) where the uptake rate is low enough to minimize starvation and the exposure duration is not excessive for weakly retained compounds.

  15. Phytate addition to soil induces changes in the abundance and expression of Bacillus β-propeller phytase genes in the rhizosphere.

    PubMed

    Jorquera, Milko A; Saavedra, Nicolás; Maruyama, Fumito; Richardson, Alan E; Crowley, David E; del C Catrilaf, Rosa; Henriquez, Evelyn J; de la Luz Mora, María

    2013-02-01

    Phytate-mineralizing rhizobacteria (PMR) perform an essential function for the mineralization of organic phosphorus but little is known about their ecology in soils and rhizosphere. In this study, PCR-based methods were developed for detection and quantification of the Bacillus β-propeller phytase (BPP) gene. Experiments were conducted to monitor the presence and persistence of a phytate-mineralizing strain, Bacillus sp. MQH19, after inoculation of soil microcosms and within the rhizosphere. The occurrence of the BPP gene in natural pasture soils from Chilean Andisols was also examined. The results showed that the Bacillus BPP gene was readily detected in sterile and nonsterile microcosms, and that the quantitative PCR (qPCR) methods could be used to monitor changes in the abundance of the BPP gene over time. Our results also show that the addition of phytate to nonsterile soils induced the expression of the BPP gene in the rhizosphere of ryegrass and the BPP gene was detected in all pasture soils sampled. This study shows that phytate addition soils induced changes in the abundance and expression of Bacillus BPP to genes in the rhizosphere and demonstrates that Bacillus BPP gene is cosmopolitan in pasture soils from Chilean Andisols.

  16. The Importance of Sample Processing in Analysis of Asbestos Content in Rocks and Soils

    NASA Astrophysics Data System (ADS)

    Neumann, R. D.; Wright, J.

    2012-12-01

    Analysis of asbestos content in rocks and soils using Air Resources Board (ARB) Test Method 435 (M435) involves the processing of samples for subsequent analysis by polarized light microscopy (PLM). The use of different equipment and procedures by commercial laboratories to pulverize rock and soil samples could result in different particle size distributions. It has long been theorized that asbestos-containing samples can be over-pulverized to the point where the particle dimensions of the asbestos no longer meet the required 3:1 length-to-width aspect ratio or the particles become so small that they no longer can be tested for optical characteristics using PLM where maximum PLM magnification is typically 400X. Recent work has shed some light on this issue. ARB staff conducted an interlaboratory study to investigate variability in preparation and analytical procedures used by laboratories performing M435 analysis. With regard to sample processing, ARB staff found that different pulverization equipment and processing procedures produced powders that have varying particle size distributions. PLM analysis of the finest powders produced by one laboratory showed all but one of the 12 samples were non-detect or below the PLM reporting limit; in contrast to the other 36 coarser samples from the same field sample and processed by three other laboratories where 21 samples were above the reporting limit. The set of 12, exceptionally fine powder samples produced by the same laboratory was re-analyzed by transmission electron microscopy (TEM) and results showed that these samples contained asbestos above the TEM reporting limit. However, the use of TEM as a stand-alone analytical procedure, usually performed at magnifications between 3,000 to 20,000X, also has its drawbacks because of the miniscule mass of sample that this method examines. The small amount of powder analyzed by TEM may not be representative of the field sample. The actual mass of the sample powder analyzed by

  17. On the asymptotic improvement of supervised learning by utilizing additional unlabeled samples - Normal mixture density case

    NASA Technical Reports Server (NTRS)

    Shahshahani, Behzad M.; Landgrebe, David A.

    1992-01-01

    The effect of additional unlabeled samples in improving the supervised learning process is studied in this paper. Three learning processes. supervised, unsupervised, and combined supervised-unsupervised, are compared by studying the asymptotic behavior of the estimates obtained under each process. Upper and lower bounds on the asymptotic covariance matrices are derived. It is shown that under a normal mixture density assumption for the probability density function of the feature space, the combined supervised-unsupervised learning is always superior to the supervised learning in achieving better estimates. Experimental results are provided to verify the theoretical concepts.

  18. 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.

  19. 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

  20. Multiplex short tandem repeat amplification of low template DNA samples with the addition of proofreading enzymes.

    PubMed

    Davis, Carey P; Chelland, Lynzee A; Pavlova, Victoria R; Illescas, María J; Brown, Kelly L; Cruz, Tracey Dawson

    2011-05-01

    With <100 pg of template DNA, routine short tandem repeat (STR) analysis often fails, resulting in no or partial profiles and increased stochastic effects. To overcome this, some have investigated preamplification methods that include the addition of proofreading enzymes to the PCR cocktail. This project sought to determine whether adding proofreading polymerases directly in the STR amplification mixture would improve the reaction when little template DNA is available. Platinum Taq High Fidelity and GeneAmp High Fidelity were tested in Profiler Plus™ STR reactions alone and in combination with AmpliTaq(®) Gold. All reactions included the additional step of a post-PCR purification step. With both pristine low template DNA and casework samples, the addition of these polymerases resulted in comparable or no improvement in the STR amplification signal. Further, stochastic effects and artifacts were observed equally across all enzyme conditions. Based on these studies, the addition of these proofreading enzymes to a multiplex STR amplification is not recommended for low template DNA work.

  1. Quantitative passive soil vapor sampling for VOCs--part 1: theory.

    PubMed

    McAlary, Todd; Wang, Xiaomin; Unger, Andre; Groenevelt, Hester; Górecki, Tadeusz

    2014-03-01

    Volatile organic compounds are the primary chemicals of concern at many contaminated sites and soil vapor sampling and analysis is a valuable tool for assessing the nature and extent of contamination. Soil gas samples are typically collected by applying vacuum to a probe in order to collect a whole-gas sample, or by drawing gas through a tube filled with an adsorbent (active sampling). There are challenges associated with flow and vacuum levels in low permeability materials, and leak prevention and detection during active sample collection can be cumbersome. Passive sampling has been available as an alternative to conventional gas sample collection for decades, but quantitative relationships between the mass of chemicals sorbed, the soil vapor concentrations, and the sampling time have not been established. This paper presents transient and steady-state mathematical models of radial vapor diffusion to a drilled hole and considerations for passive sampler sensitivity and practical sampling durations. The results indicate that uptake rates in the range of 0.1 to 1 mL min(-1) will minimize the starvation effect for most soil moisture conditions and provide adequate sensitivity for human health risk assessment with a practical sampling duration. This new knowledge provides a basis for improved passive soil vapour sampler design.

  2. Operable Unit 3-13, Group 3, Other Surface Soils (Phase II) Field Sampling Plan

    SciTech Connect

    G. L. Schwendiman

    2006-07-27

    This Field Sampling Plan describes the Operable Unit 3-13, Group 3, Other Surface Soils, Phase II remediation field sampling activities to be performed at the Idaho Nuclear Technology and Engineering Center located within the Idaho National Laboratory Site. Sampling activities described in this plan support characterization sampling of new sites, real-time soil spectroscopy during excavation, and confirmation sampling that verifies that the remedial action objectives and remediation goals presented in the Final Record of Decision for Idaho Nuclear Technology and Engineering Center, Operable Unit 3-13 have been met.

  3. 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.

  4. 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.

  5. Apollo 16 regolith breccias and soils - Recorders of exotic component addition to the Descartes region of the moon

    NASA Technical Reports Server (NTRS)

    Simon, S. B.; Papike, J. J.; Laul, J. C.; Hughes, S. S.; Schmitt, R. A.

    1988-01-01

    Using the subdivision of Apollo 16 regolith breccias into ancient (about 4 Gyr) and younger samples (McKay et al., 1986), with the present-day soils as a third sample, a petrologic and chemical determination of regolith evolution and exotic component addition at the A-16 site was performed. The modal petrologies and mineral and chemical compositions of the regolith breccias in the region are presented. It is shown that the early regolith was composed of fragments of plutonic rocks, impact melt rocks, and minerals and impact glasses. It is found that KREEP lithologies and impact melts formed early in lunar history. The mare components, mainly orange high-TiO2 glass and green low-TiO2 glass, were added to the site after formation of the ancient breccias and prior to the formation of young breccias. The major change in the regolith since the formation of the young breccias is an increase in maturity represented by the formation of fused soil particles with prolonged exposure to micrometeorite impacts.

  6. Sampling protocol recommendations for measuring soil organic carbon stocks in the tropics

    NASA Astrophysics Data System (ADS)

    van Straaten, Oliver; Veldkamp, Edzo; Corre, Marife D.

    2013-04-01

    In the tropics, there is an urgent need for cost effective sampling approaches to quantify soil organic carbon (SOC) changes associated with land-use change given the lack of reliable data. The tropics are especially important considering the high deforestation rates, the huge belowground carbon pool and the fast soil carbon turnover rates. In the framework of a pan-tropic (Peru, Cameroon and Indonesia) land-use change study, some highly relevant recommendations on the SOC stocks sampling approaches have emerged. In this study, where we focused on deeply weathered mineral soils, we quantified changes in SOC stock following land-use change (deforestation and subsequent establishment of other land-uses). We used a space-for-time substitution sampling approach, measured SOC stocks in the top three meters of soil and compared recently converted land-uses with adjacent reference forest plots. In each respective region we investigated the most predominant land-use trajectories. In total 157 plots were established across the three countries, where soil samples were taken to a depth of three meters from a central soil pit and from the topsoil (to 0.5m) from 12 pooled composite samples. Finding 1 - soil depth: despite the fact that the majority of SOC stock from the three meter profile is found below one meter depth (50 to 60 percent of total SOC stock), the significant changes in SOC were only measured in the top meter of soil, while the subsoil carbon stock remained relatively unchanged by the land-use conversion. The only exception was for older (>50 yrs) cacao plantations in Cameroon where significant decreases were found below one meter. Finding 2 - pooled composite samples taken across the plot provided more spatially representative estimates of SOC stocks than samples taken from the central soil pit.

  7. Understanding soil-gas velocity leads to new sampling techniques

    SciTech Connect

    Roy, K.A.

    1989-12-01

    Predicting when periods of maximum vertical gas velocity occur for any geographic point mightily increases the sensitivity and reliability of detection. This article discusses sampling programs. Sampling programs can be completed during periods of maximum velocity, allowing field workers to collect the maximum amount of contaminant in trace-gas form per given unit of time.

  8. Local versus field scale soil heterogeneity characterization - a challenge for representative sampling in pollution studies

    NASA Astrophysics Data System (ADS)

    Kardanpour, Z.; Jacobsen, O. S.; Esbensen, K. H.

    2015-12-01

    This study is a contribution to development of a heterogeneity characterization facility for "next-generation" soil sampling aimed, for example, at more realistic and controllable pesticide variability in laboratory pots in experimental environmental contaminant assessment. The role of soil heterogeneity in quantification of a set of exemplar parameters is described, including a brief background on how heterogeneity affects sampling/monitoring procedures in environmental pollutant studies. The theory of sampling (TOS) and variographic analysis has been applied to develop a more general fit-for-purpose soil heterogeneity characterization approach. All parameters were assessed in large-scale transect (1-100 m) vs. small-scale (0.1-0.5 m) replication sampling point variability. Variographic profiles of experimental analytical results from a specific well-mixed soil type show that it is essential to sample at locations with less than a 2.5 m distance interval to benefit from spatial auto-correlation and thereby avoid unnecessary, inflated compositional variation in experimental pots; this range is an inherent characteristic of the soil heterogeneity and will differ among other soils types. This study has a significant carrying-over potential for related research areas, e.g. soil science, contamination studies, and environmental monitoring and environmental chemistry.

  9. MACRO- MICRO-PURGE SOIL GAS SAMPLING METHODS FOR THE COLLECTION OF CONTAMINANT VAPORS

    EPA Science Inventory

    Purging influence on soil gas concentrations for volatile organic compounds (VOCs), as affected by sampling tube inner diameter and sampling depth (i.e., dead-space purge volume), was evaluated at different field sites. A macro-purge sampling system consisted of a standard hollo...

  10. A probe for sampling interstitial waters of stream sediments and bog soils

    USGS Publications Warehouse

    Nowlan, G.A.; Carollo, C.

    1974-01-01

    A probe for sampling interstitial waters of stream sediments and bog soils is described. Samples can be obtained within a stratigraphic interval of 2-3 cm, to a depth of 60-80 cm, and with little or no contamination of the samples by sediment or air. ?? 1974.

  11. Challenges in Bulk Soil Sampling and Analysis for Vapor Intrusion Screening of Soil

    EPA Science Inventory

    This draft Engineering Issue Paper discusses technical issues with monitoring soil excavations for VOCs and describes options for such monitoring as part of a VI pathway assessment at sites where soil excavation is being considered or used as part of the remedy for VOC-contaminat...

  12. Nitrogen retention capacity of a northern hardwood forest soil under ammonium sulfate additions

    SciTech Connect

    Christ, M. |; Zhang, Y.; Likens, G.E.

    1995-08-01

    To determine the N-retaining capacity of a beech-dominated stand in the Hubbard Brook Experimental Forest, we added (NH{sub 4}){sub 2}SO{sub 4} at three levels (40, 160 and 520 kg N{center_dot}ha{sup {minus}1}{center_dot}yr{sup {minus}1}) to replicate plots in monthly increments for two years, and measured NH{sub 4}{sup +} and NO{sub 3}{sup {minus}} concentrations in monthly samples from zero-tension lysimeters. The two lower treatment levels failed to increase N loss through the deepest soils horizon when compared to controls. Plots under the highest treatment level retained >95% of the added N; NH{sub 4}{sup +} accounted for 77% of the leaching loss. The treatments caused an accumulation of exchangeable NH{sub 4}{sup +} in the soil, but concentrations of exchangeable NO{sub 3}{sup {minus}} remained small, even after samples were incubated at room temperature. Leaching, uptake by plants, and the increase exchangeable NH{sub 4}{sup +} accounted for 3-25% of the added N. Accumulation of available N without nitrification contradicts common expectations concerning N saturation. It was not clear why excess N was not nitrified. 74 refs., 4 figs., 4 tabs.

  13. Using Soil Apparent Electrical Conductivity to Optimize Sampling of Soil Penetration Resistance and to Improve the Estimations of Spatial Patterns of Soil Compaction

    PubMed Central

    Siqueira, Glécio Machado; Dafonte, Jorge Dafonte; Bueno Lema, Javier; Valcárcel Armesto, Montserrat; Silva, Ênio Farias França e

    2014-01-01

    This study presents a combined application of an EM38DD for assessing soil apparent electrical conductivity (ECa) and a dual-sensor vertical penetrometer Veris-3000 for measuring soil electrical conductivity (ECveris) and soil resistance to penetration (PR). The measurements were made at a 6 ha field cropped with forage maize under no-tillage after sowing and located in Northwestern Spain. The objective was to use data from ECa for improving the estimation of soil PR. First, data of ECa were used to determine the optimized sampling scheme of the soil PR in 40 points. Then, correlation analysis showed a significant negative relationship between soil PR and ECa, ranging from −0.36 to −0.70 for the studied soil layers. The spatial dependence of soil PR was best described by spherical models in most soil layers. However, below 0.50 m the spatial pattern of soil PR showed pure nugget effect, which could be due to the limited number of PR data used in these layers as the values of this parameter often were above the range measured by our equipment (5.5 MPa). The use of ECa as secondary variable slightly improved the estimation of PR by universal cokriging, when compared with kriging. PMID:25610899

  14. Using soil apparent electrical conductivity to optimize sampling of soil penetration resistance and to improve the estimations of spatial patterns of soil compaction.

    PubMed

    Machado Siqueira, Glécio; Dafonte Dafonte, Jorge; Bueno Lema, Javier; Valcárcel Armesto, Montserrat; França e Silva, Ênio Farias

    2014-01-01

    This study presents a combined application of an EM38DD for assessing soil apparent electrical conductivity (ECa) and a dual-sensor vertical penetrometer Veris-3000 for measuring soil electrical conductivity (ECveris) and soil resistance to penetration (PR). The measurements were made at a 6 ha field cropped with forage maize under no-tillage after sowing and located in Northwestern Spain. The objective was to use data from ECa for improving the estimation of soil PR. First, data of ECa were used to determine the optimized sampling scheme of the soil PR in 40 points. Then, correlation analysis showed a significant negative relationship between soil PR and ECa, ranging from -0.36 to -0.70 for the studied soil layers. The spatial dependence of soil PR was best described by spherical models in most soil layers. However, below 0.50 m the spatial pattern of soil PR showed pure nugget effect, which could be due to the limited number of PR data used in these layers as the values of this parameter often were above the range measured by our equipment (5.5 MPa). The use of ECa as secondary variable slightly improved the estimation of PR by universal cokriging, when compared with kriging.

  15. Addition of organic amendments contributes to C sequestration in trace element contaminated soils.

    NASA Astrophysics Data System (ADS)

    del Mar Montiel Rozas, María; Panettier, Marco; Madejón Rodríguez, Paula; Madejón Rodríguez, Engracia

    2015-04-01

    Nowadays, the study of global C cycle and the different natural sinks of C have become especially important in a climate change context. Fluxes of C have been modified by anthropogenic activities and, presently, the global objective is the decrease of net CO2 emission. For this purpose, many studies are being conducted at local level for evaluate different C sequestration strategies. These techniques must be, in addition to safe in the long term, environmentally friendly. Restoration of contaminated and degraded areas is considered as a strategy for SOC sequestration. Our study has been carried out in the Guadiamar Green Corridor (Seville, Spain) affected by the Aznalcóllar mining accident. This accident occurred 16 years ago, due to the failure of the tailing dam which contained 4-5 million m3 of toxic tailings (slurry and acid water).The affected soils had a layer of toxic sludge containing heavy metals as As, Cd, Cu, Pb and Zn. Restoration techniques began to be applied just after the accident, including the removal of the toxic sludge and a variable layer of topsoil (10-30 cm) from the surface. In a second phase, in a specific area (experimental area) of the Green Corridor the addition of organic amendments (Biosolid compost (BC) and Leonardite (LE), a low grade coal rich in humic acids) was carried out to increase pH, organic matter and fertility in a soil which lost its richest layer during the clean-up operation. In our experimental area, half of the plots (A) received amendments for four years (2002, 2003, 2006 and 2007) whereas the other half (B) received amendments only for two years (2002-2003). To compare, plots without amendments were also established. Net balance of C was carried out using values of Water Soluble Carbon (WSC) and Total Organic Carbon (TOC) for three years (2012, 2013 and 2015). To eliminate artificial changes carried out in the plots, amendment addition and withdrawal of biomass were taken into account to calculate balance of kg TOC

  16. Geochemistry of Soil Samples from 50 Solution-Collapse Features on the Coconino Plateau, Northern Arizona

    USGS Publications Warehouse

    Van Gosen, Bradley S.; Wenrich, Karen J.

    1991-01-01

    Soil sampling surveys were conducted during 1984-1986 across 50 solution-collapse features exposed on the Coconino Plateau of northern Arizona in order to determine whether soil geochemistry can be used to distinguish mineralized breccia pipes from unmineralized collapse features. The 50 sampled features represent the variety of collapse features that crop out on plateau surfaces in northwestern Arizonaoodeeplyorooted solution-collapse breccia pipes, near-surface gypsum collapses, and sinkholes. Of the 50 features that were sampled in this study, 3 are confirmed breccia pipes that contain significant uranium and base-metal minerals, I is believed to be a sinkhole with no economic potential, and 4 are stratabound copper deposits whose possible relationship to breccia pipes is yet to be determined. The remaining collapse features are suspected to overlie breccia pipes, although some of these may represent near surface gypsum collapse features. However, no exploratory drilling results or breccia exposures exist to indicate their underlying structure. The low cost and ease of soil sampling suggested that this technique be evaluated for breccia pipe exploration. This report provides the locations and geochemical results for the soil sampling surveys and brief descriptions of the 50 collapse features. The analytical results of almost 2,000 soil samples are provided in tabular hardcopy and dBase III Plus diskcopy format. The analytical data is provided in digital format to allow the reader to choose their own methods for evaluating the effectiveness of soil sampling over known and suspected breccia pipes. A pilot survey conducted over 17 collapse features in 1984 suggested that soil sampling might be useful in distinguishing mineralized breccia pipes from other circular features. Followup detailed surveys in 1985 and 1986 used a radial sampling pattern at each of 50 sites; at least one third of the samples were collected from areas outside of the collapse feature to

  17. Responses of soil enzyme activity and microbial community compositions to nitrogen addition in bulk and microaggregate soil in the temperate steppe of Inner Mongolia

    NASA Astrophysics Data System (ADS)

    Shi, Yao; Sheng, Lianxi; Wang, Zhongqiang; Zhang, Xinyu; He, Nianpeng; Yu, Qiang

    2016-10-01

    In order to explore the responses of soil enzyme activities and microbial community compositions to long-term nitrogen (N) addition in both bulk soil and microaggregate of chestnut soil, we conducted a 7-year urea addition experiment with N treatments at 6 levels (0, 56, 112, 224, 392 and 560 kg N ha-1 yr-1) in a temperate steppe of Inner Mongolia in China. Soil properties and the activities of four enzymes involved in carbon (C), nitrogen (N) and phosphorus (P) cycling were measured in both bulk soil and microaggregate, and phospholipid fatty acids (PLFAs) were measured in bulk soil. The results indicated that: 1) in bulk soil, N addition significantly decreased β-1,4-glucosidase (BG) and leucine aminopeptidase (LAP) activities at the treatment amounts of 224, 392 and 560 kg N ha-1 yr-1, and obviously suppressed β-1,4-N-acetylglucosaminidase (NAG) activity at the treatment amount of 560 kg N ha-1 yr-1. N addition enhanced total PLFAs (totPLFAs) and bacterial PLFAs (bacPLFAs) at the treatment amounts of 392 and 560 kg N ha-1 yr-1, respectively, but fungal PLFAs showed no response to N addition. The activities of BG, NAG and LAP were positively correlated with soil pH, but negatively correlated with the concentration of NH 4 + -N; 2) in microaggregate (53-250 μm), the activities of BG, NAG and AP showed no response to increased addition of N, but the significantly decreased LAP activity was observed at the treatment amount of 392 kg N ha-1 yr-1. These results suggested that enzyme activities were more sensitive to N addition than PLFA biomarkers in soil, and LAP activity in microaggregate may be a good indicator for evaluating N cycle response to long-term N addition.

  18. Neutron Activation Analysis of Soil Samples from Different Parts of Edirne in Turkey*

    NASA Astrophysics Data System (ADS)

    Zaim, N.; Dogan, C.; Camtakan, Z.

    2016-05-01

    The concentrations of constituent elements were determined in soil samples collected from different parts of the Maritza Basin, Edirne, Turkey. Neutron activation analysis, an extremely accurate technique, and the comparator method (using a standard) were applied for the first time in this region. After preparing the soil samples for neutron activation analysis, they were activated with thermal neutrons in a nuclear reactor, TRIGA-MARK II, at Istanbul Technical University. The activated samples were analyzed using a high-efficiency high-purity germanium detector, and gamma spectrometry was employed to determine the elemental concentration in the samples. Eight elements (chromium, manganese, cobalt, zinc, arsenic, molybdenum, cadmium, and barium) were qualitatively and quantitatively identified in 36 samples. The concentrations of some elements in the soil samples were high compared with values reported in the literature.

  19. The effects of fire severity on black carbon additions to forest soils - 10 years post fire

    NASA Astrophysics Data System (ADS)

    Poore, R.; Wessman, C. A.; Buma, B.

    2013-12-01

    Wildfires play an active role in the global carbon cycle. While large amounts of carbon dioxide are released, a small fraction of the biomass consumed by the fire is only partially combusted, yielding soot and charcoal. These products, also called black carbon (BC) make up only 1-5% of the biomass burnt, yet they can have a disproportionate effect on both the atmosphere and fluxes in long-term carbon pools. This project specifically considers the fraction that is sequestered in forest soils. Black carbon is not a specific compound, and exists along a continuum ranging from partially burned biomass to pure carbon or graphite. Increasing aromaticity as the result of partial combustion means charcoal is highly resistant to oxidation. Although debated, most studies indicate a turnover time on the order of 500-1,000 years in warm, wet, aerobic soils. Charcoal may function as a long-term carbon sink, however its overall significance depends on its rate of formation and loss. At the landscape level, fire characteristics are one of the major factors controlling charcoal production. A few studies suggest that charcoal production increases with cooler, less-severe fires. However, there are many factors to tease apart, partly because of a lack of specificity in how fire severity is defined. Within this greater context, our lab has been working on a landscape-level study within Routt National Forest, north of Steamboat Springs, Colorado. In 2002, a large fire swept through a subalpine spruce, fir and lodgepole pine forest. In 2011-2013 we sampled BC pools in 44 plots across a range of fire severities from unburned to severe crown We hypothesized that charcoal stocks will be higher in areas of low severity fire as compared to high severity because of decreased re-combustion of charcoal in the organic soil and increased overall charcoal production due to lower temperatures. In each of our plots we measured charcoal on snags and coarse woody debris, sampled the entire organic

  20. Spatial Variation in Soil Properties among North American Ecosystems and Guidelines for Sampling Designs

    PubMed Central

    Loescher, Henry; Ayres, Edward; Duffy, Paul; Luo, Hongyan; Brunke, Max

    2014-01-01

    Soils are highly variable at many spatial scales, which makes designing studies to accurately estimate the mean value of soil properties across space challenging. The spatial correlation structure is critical to develop robust sampling strategies (e.g., sample size and sample spacing). Current guidelines for designing studies recommend conducting preliminary investigation(s) to characterize this structure, but are rarely followed and sampling designs are often defined by logistics rather than quantitative considerations. The spatial variability of soils was assessed across ∼1 ha at 60 sites. Sites were chosen to represent key US ecosystems as part of a scaling strategy deployed by the National Ecological Observatory Network. We measured soil temperature (Ts) and water content (SWC) because these properties mediate biological/biogeochemical processes below- and above-ground, and quantified spatial variability using semivariograms to estimate spatial correlation. We developed quantitative guidelines to inform sample size and sample spacing for future soil studies, e.g., 20 samples were sufficient to measure Ts to within 10% of the mean with 90% confidence at every temperate and sub-tropical site during the growing season, whereas an order of magnitude more samples were needed to meet this accuracy at some high-latitude sites. SWC was significantly more variable than Ts at most sites, resulting in at least 10× more SWC samples needed to meet the same accuracy requirement. Previous studies investigated the relationship between the mean and variability (i.e., sill) of SWC across space at individual sites across time and have often (but not always) observed the variance or standard deviation peaking at intermediate values of SWC and decreasing at low and high SWC. Finally, we quantified how far apart samples must be spaced to be statistically independent. Semivariance structures from 10 of the 12-dominant soil orders across the US were estimated, advancing our

  1. Spatial variation in soil properties among North American ecosystems and guidelines for sampling designs.

    PubMed

    Loescher, Henry; Ayres, Edward; Duffy, Paul; Luo, Hongyan; Brunke, Max

    2014-01-01

    Soils are highly variable at many spatial scales, which makes designing studies to accurately estimate the mean value of soil properties across space challenging. The spatial correlation structure is critical to develop robust sampling strategies (e.g., sample size and sample spacing). Current guidelines for designing studies recommend conducting preliminary investigation(s) to characterize this structure, but are rarely followed and sampling designs are often defined by logistics rather than quantitative considerations. The spatial variability of soils was assessed across ∼1 ha at 60 sites. Sites were chosen to represent key US ecosystems as part of a scaling strategy deployed by the National Ecological Observatory Network. We measured soil temperature (Ts) and water content (SWC) because these properties mediate biological/biogeochemical processes below- and above-ground, and quantified spatial variability using semivariograms to estimate spatial correlation. We developed quantitative guidelines to inform sample size and sample spacing for future soil studies, e.g., 20 samples were sufficient to measure Ts to within 10% of the mean with 90% confidence at every temperate and sub-tropical site during the growing season, whereas an order of magnitude more samples were needed to meet this accuracy at some high-latitude sites. SWC was significantly more variable than Ts at most sites, resulting in at least 10× more SWC samples needed to meet the same accuracy requirement. Previous studies investigated the relationship between the mean and variability (i.e., sill) of SWC across space at individual sites across time and have often (but not always) observed the variance or standard deviation peaking at intermediate values of SWC and decreasing at low and high SWC. Finally, we quantified how far apart samples must be spaced to be statistically independent. Semivariance structures from 10 of the 12-dominant soil orders across the US were estimated, advancing our

  2. Effects of Biochar Addition on CO2 and N2O Emissions following Fertilizer Application to a Cultivated Grassland Soil.

    PubMed

    Chen, Jingjing; Kim, Hyunjin; Yoo, Gayoung

    2015-01-01

    Carbon (C) sequestration potential of biochar should be considered together with emission of greenhouse gases when applied to soils. In this study, we investigated CO2 and N2O emissions following the application of rice husk biochars to cultivated grassland soils and related gas emissions tos oil C and nitrogen (N) dynamics. Treatments included biochar addition (CHAR, NO CHAR) and amendment (COMPOST, UREA, NO FERT). The biochar application rate was 0.3% by weight. The temporal pattern of CO2 emissions differed according to biochar addition and amendments. CO2 emissions from the COMPOST soils were significantly higher than those from the UREA and NO FERT soils and less CO2 emission was observed when biochar and compost were applied together during the summer. Overall N2O emission was significantly influenced by the interaction between biochar and amendments. In UREA soil, biochar addition increased N2O emission by 49% compared to the control, while in the COMPOST and NO FERT soils, biochar did not have an effect on N2O emission. Two possible mechanisms were proposed to explain the higher N2O emissions upon biochar addition to UREA soil than other soils. Labile C in the biochar may have stimulated microbial N mineralization in the C-limited soil used in our study, resulting in an increase in N2O emission. Biochar may also have provided the soil with the ability to retain mineral N, leading to increased N2O emission. The overall results imply that biochar addition can increase C sequestration when applied together with compost, and might stimulate N2O emission when applied to soil amended with urea.

  3. Effects of Biochar Addition on CO2 and N2O Emissions following Fertilizer Application to a Cultivated Grassland Soil

    PubMed Central

    Chen, Jingjing; Kim, Hyunjin; Yoo, Gayoung

    2015-01-01

    Carbon (C) sequestration potential of biochar should be considered together with emission of greenhouse gases when applied to soils. In this study, we investigated CO2 and N2O emissions following the application of rice husk biochars to cultivated grassland soils and related gas emissions tos oil C and nitrogen (N) dynamics. Treatments included biochar addition (CHAR, NO CHAR) and amendment (COMPOST, UREA, NO FERT). The biochar application rate was 0.3% by weight. The temporal pattern of CO2 emissions differed according to biochar addition and amendments. CO2 emissions from the COMPOST soils were significantly higher than those from the UREA and NO FERT soils and less CO2 emission was observed when biochar and compost were applied together during the summer. Overall N2O emission was significantly influenced by the interaction between biochar and amendments. In UREA soil, biochar addition increased N2O emission by 49% compared to the control, while in the COMPOST and NO FERT soils, biochar did not have an effect on N2O emission. Two possible mechanisms were proposed to explain the higher N2O emissions upon biochar addition to UREA soil than other soils. Labile C in the biochar may have stimulated microbial N mineralization in the C-limited soil used in our study, resulting in an increase in N2O emission. Biochar may also have provided the soil with the ability to retain mineral N, leading to increased N2O emission. The overall results imply that biochar addition can increase C sequestration when applied together with compost, and might stimulate N2O emission when applied to soil amended with urea. PMID:26020941

  4. Effects of Biochar Addition on CO2 and N2O Emissions following Fertilizer Application to a Cultivated Grassland Soil.

    PubMed

    Chen, Jingjing; Kim, Hyunjin; Yoo, Gayoung

    2015-01-01

    Carbon (C) sequestration potential of biochar should be considered together with emission of greenhouse gases when applied to soils. In this study, we investigated CO2 and N2O emissions following the application of rice husk biochars to cultivated grassland soils and related gas emissions tos oil C and nitrogen (N) dynamics. Treatments included biochar addition (CHAR, NO CHAR) and amendment (COMPOST, UREA, NO FERT). The biochar application rate was 0.3% by weight. The temporal pattern of CO2 emissions differed according to biochar addition and amendments. CO2 emissions from the COMPOST soils were significantly higher than those from the UREA and NO FERT soils and less CO2 emission was observed when biochar and compost were applied together during the summer. Overall N2O emission was significantly influenced by the interaction between biochar and amendments. In UREA soil, biochar addition increased N2O emission by 49% compared to the control, while in the COMPOST and NO FERT soils, biochar did not have an effect on N2O emission. Two possible mechanisms were proposed to explain the higher N2O emissions upon biochar addition to UREA soil than other soils. Labile C in the biochar may have stimulated microbial N mineralization in the C-limited soil used in our study, resulting in an increase in N2O emission. Biochar may also have provided the soil with the ability to retain mineral N, leading to increased N2O emission. The overall results imply that biochar addition can increase C sequestration when applied together with compost, and might stimulate N2O emission when applied to soil amended with urea. PMID:26020941

  5. 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.

  6. Plant-Soil Relationships of Bromus tectorum L.: Interactions among Labile Carbon Additions, Soil Invasion Status, and Fertilizer.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Invasion of western North America by the annual exotic grass Bromus tectorum L. (cheatgrass) has been an ecological disaster. High soil bioavailability of nitrogen is a contributing factor in the invasive potential of B. tectorum. Application of labile carbon sources to the soil can immobilize soil ...

  7. Naturally occurring radionuclides and rare earth elements in weathered Japanese soil samples

    NASA Astrophysics Data System (ADS)

    Sahoo, Sarata; Hosoda, Masahiro; Prasad, Ganesh; Takahashi, Hiroyuki; Sorimachi, Atsuyuki; Ishikawa, Tetsuo; Tokonami, Shinji; Uchida, Shigeo

    2013-08-01

    The activity concentrations of 226Ra and 228Ac in weathered Japanese soils from two selected prefectures have been measured using a γ-ray spectroscopy system with high purity germanium detector. The uranium, thorium, and rare earth elements (REEs) concentrations were determined from the same soil samples using inductively coupled plasma mass spectrometry (ICP-MS). For example, granitic rocks contain higher amounts of U, Th, and light REEs compared to other igneous rocks such as basalt and andesites. Therefore, it is necessary to understand the interaction between REEs and nature of soils since soils are complex heterogeneous mixture of organic and inorganic solids, water, and gases. In this paper, we will discuss about distribution pattern of 238U and 232Th along with REEs in soil samples of weathered acid rock (granite) collected from two prefectures of Japan: Hiroshima and Miyagi.

  8. Chemical analyses of soil samples collected from the Sandia National Laboratories/NM, Tonopah Test Range environs, 1994-2005.

    SciTech Connect

    Deola, Regina Anne; Oldewage, Hans D.; Herrera, Heidi M.; Miller, Mark Laverne

    2006-05-01

    From 1994 through 2005, the Environmental Management Department of Sandia National Laboratories (SNL) at the Tonopah Test Range (TTR), NV, has collected soil samples at numerous locations on-site, on the perimeter, and off-site for the purpose of determining potential impacts to the environs from operations at TTR. These samples were submitted to an analytical laboratory of metal-in-soil analyses. Intercomparisons of these results were then made to determine if there was any statistical difference between on-site, perimeter, and off-site samples, or if there were increasing or decreasing trends which indicated that further investigation may be warranted. This work provided the SNL Environmental Management Department with a sound baseline data reference against which to compare future operational impacts. In addition, it demonstrates the commitment that the Laboratories have to go beyond mere compliance to achieve excellence in its operations. This data is presented in graphical format with narrative commentaries on particular items of interest.

  9. LRO Diviner Soil Composition Measurements - Lunar Sample Ground Truth

    NASA Technical Reports Server (NTRS)

    Allen, Carlton C.; Greenhagen, Benjamin T.; Paige, David A.

    2010-01-01

    The Diviner Lunar Radiometer Experiment on the Lunar Reconnaissance Orbiter [1,2] includes three thermal infrared channels spanning the wavelength ranges 7.55-8.05 microns 8.10-8.40 microns, and 8.38-8.68 microns. These "8 micron" bands were specifically selected to measure the "Christiansen feature". The wavelength location of this feature, referred to herein as CF, is particularly sensitive to silicate minerals including plagioclase, pyroxene, and olivine the major crystalline components of lunar rocks and soil. The general trend is that lower CF values are correlated with higher silica content and higher CF values are correlated with lower silica content. In a companion abstract, Greenhagen et al. [3] discuss the details of lunar mineral identification using Diviner data.

  10. Arsenic(V) adsorption-desorption in agricultural and mine soils: Effects of organic matter addition and phosphate competition.

    PubMed

    Arco-Lázaro, Elena; Agudo, Inés; Clemente, Rafael; Bernal, M Pilar

    2016-09-01

    High total and bioavailable concentrations of As in soils represent a potential risk for groundwater contamination and entry in the food chain. The use of organic amendments in the remediation of As-contaminated soils has been found to produce distinct effects on the solubility of As in the soil. Therefore, knowledge about As adsorption-desorption processes that govern its solubility in soil is of relevance in order to predict the behaviour of this element during these processes. In this paper, the objective was to determine As adsorption and desorption in four different soils, with and without compost addition, and also in competition with phosphate, through the determination of sorption isotherms. Batch experiments were carried out using three soils affected differently by previous mining activity of the Sierra Minera of La Unión-Cartagena (SE Spain) and an agricultural soil from Segovia province (central Spain). Adsorption was higher in the mining soils (and highest in the acidic one) than in the agricultural soils, although the latter were not affected negatively by organic matter or phosphate competition for sorption sites. The results show that As adsorption in most soils, both with and without compost, fitted better a multimolecular layer model (Freundlich), whereas As adsorption in competition with P fitted a monolayer model (Langmuir). Moreover, the use of compost and phosphate reduced the adsorption of As in the mining soils, while in the agricultural soils compost increased their low adsorption capacity. Therefore, the use of compost can be a good option to favour As immobilisation in soils of low adsorption, but knowledge of the soil composition will be crucial to predict the effects of organic amendments on As solubility in soils and its associated environmental risk.

  11. Arsenic(V) adsorption-desorption in agricultural and mine soils: Effects of organic matter addition and phosphate competition.

    PubMed

    Arco-Lázaro, Elena; Agudo, Inés; Clemente, Rafael; Bernal, M Pilar

    2016-09-01

    High total and bioavailable concentrations of As in soils represent a potential risk for groundwater contamination and entry in the food chain. The use of organic amendments in the remediation of As-contaminated soils has been found to produce distinct effects on the solubility of As in the soil. Therefore, knowledge about As adsorption-desorption processes that govern its solubility in soil is of relevance in order to predict the behaviour of this element during these processes. In this paper, the objective was to determine As adsorption and desorption in four different soils, with and without compost addition, and also in competition with phosphate, through the determination of sorption isotherms. Batch experiments were carried out using three soils affected differently by previous mining activity of the Sierra Minera of La Unión-Cartagena (SE Spain) and an agricultural soil from Segovia province (central Spain). Adsorption was higher in the mining soils (and highest in the acidic one) than in the agricultural soils, although the latter were not affected negatively by organic matter or phosphate competition for sorption sites. The results show that As adsorption in most soils, both with and without compost, fitted better a multimolecular layer model (Freundlich), whereas As adsorption in competition with P fitted a monolayer model (Langmuir). Moreover, the use of compost and phosphate reduced the adsorption of As in the mining soils, while in the agricultural soils compost increased their low adsorption capacity. Therefore, the use of compost can be a good option to favour As immobilisation in soils of low adsorption, but knowledge of the soil composition will be crucial to predict the effects of organic amendments on As solubility in soils and its associated environmental risk. PMID:27239690

  12. [Soil greenhouse gases emission from an Acacia crassicarpa plantation under effects of understory removal and Cassia alata addition].

    PubMed

    Li, Hai-Fang; Zhang, Xing-Feng

    2010-03-01

    Forest soil is one of the main sources of greenhouse gases CO2, CH4, and N2O. By using static chamber and GS technique, this paper measured in situ the CO2, CH4, and N2O fluxes of Acacia crassicarpa plantation in Heshan Hilly Land Interdisciplinary Experimental Station under Chinese Academy of Sciences (CAS), and studied the soil CO2, CH4 and N2O emissions from the plantation under effects of understory removal and Cassia alata addition. The CO2 flux of the plantation maintained at a higher level during rainy season but decreased obviously in dry season, while the CH4 and N2O fluxes varied widely from September to November, with the peaks in October. Under the effects of understory removal and C. alata addition, the soil in the plantation could be a sink or a source of CH4, but consistently a source of CO2 and N2O. Understory removal enhanced the soil CO2 emission (P < 0.05 ), C. alata addition increased the soil CH4 emission (P < 0.05), while both understory removal and C. alata addition increased the soil N2O emission (P < 0.05). Surface soil temperature, moisture content, NO3(-) -N concentration, and microbial biomass carbon were the main factors affecting the soil CO2, CH4 and N2O emissions.

  13. Integrating legacy soil information in a Digital Soil Mapping approach based on a modified conditioned Latin Hypercube Sampling design

    NASA Astrophysics Data System (ADS)

    Stumpf, Felix; Schmidt, Karsten; Behrens, Thorsten; Schoenbrodt-Stitt, Sarah; Scholten, Thomas

    2014-05-01

    One crucial component of a Digital Soil Mapping (DSM) framework is outlined by geo-referenced soil observations. Nevertheless, highly informative legacy soil information, acquired by traditional soil surveys, is often neglected due to lacking accordance with specific statistical DSM designs. The focus of this study is to integrate legacy data into a state-of-the-art DSM approach, based on a modified conditioned Latin Hypercube Sampling (cLHS) design and Random Forest. Furthermore, by means of the cLHS modification the scope of actually unique cLHS sampling locations is widened in order to compensate limited accessability in the field. As well, the maximally stratified cLHS design is not diluted by the modification. Exemplarily the target variables of the modelling are represented by sand and clay fractions. The study site is a small mountainous hydrological catchment of 4.2 km² in the reservoir of the Three Gorges Dam in Central China. The modification is accomplished by demarcating the histogram borders of each cLHS stratum, which are based on the multivariate cLHS feature space. Thereby, all potential sample locations per stratum are identified. This provides a possibility to integrate legacy data samples that match one of the newly created sample locations, and flexibility with respect to field accessibility. Consequently, six legacy data samples, taken from a total sample size of n = 30 were integrated into the sampling design and for all strata several potential sample locations are identified. The comparability of the modified and standard cLHS data sets is approved by (i) identifying their feature space coverage with respect to the cLHS stratifying variables, and (ii) by assessing the Random Forest accuracy estimates.

  14. Hydrocarbon Magnetic Authigenesis Mechanisms in Well and Soil Samples: Review of Studies in Venezuela

    NASA Astrophysics Data System (ADS)

    Aldana, M.; Diaz, M.; Costanzo, V.

    2008-05-01

    In recent studies we have tried to establish the correlation between shallow micromagnetic anomalies from oil wells and soil samples, with the underlying reservoir. We have combined rock magnetic experiments with Electronic Paramagnetic Resonance (EPR) studies. Logs of Magnetic Susceptibility (MS), Extractable Organic Matter Concentration (EOMC) and Organic Matter Free Radical Concentration (OMFRC) have been compared. Additionally, rock magnetic and EPR experiments were carried out to identify the magnetic phases responsible for these anomalies. In wells from oil fields located in western Venezuela, MS and EOMC anomalies coincide at the same depth levels, and OMFRC anomalies lie close to them. These anomalies are associated to framboids of authigenic magnetite. In samples from eastern Venezuela oil fields, MS anomalies seem to be caused mainly by the presence of Fe sulphides (i.e. greigite). EOMC peaks do not coincide at the same depth levels of their MS counterparts. These results lead us to the conclusion that two different authigenic processes could operate. In western Venezuela, secondary magnetic minerals could be produced by the achievement of proper themochemical conditions, reached at shallow depth levels, combined with the presence of organic matter. The hydrocarbon gas leakage alters the organic matter, and a net electron transfer from this degraded matter to Fe(III) should occur, precipitating Fe(II) magnetic minerals (e.g. magnetite). Results from soil samples at a nearby prospective area suggest a similar process. In this case the alteration of organic matter has been observed via remote sensors. On the other hand, in eastern Venezuela oil fields, high concentrations of H2S at shallow depth levels, might allow the formation of secondary Fe-sulphides without the presence of organic matter. Different results for these two areas could be linked to their inherent distinct structural complexities and chemical properties of their hydrocarbons.

  15. [Spatial Heterogeneity of Soil Respiration in a Larch Plantation of North China at Different Sampling Scales].

    PubMed

    Yan, Jun-xia; Liang, Ya-nan; Li, Hong-jian; Li, Jun-jian

    2015-12-01

    Based on observations of soil respiration rate (Rs) and both biotic and abiotic factors in Pangquangou Nature Reserve at three sampling scales (4, 2, and 1 m), we studied the spatial heterogeneity of Rs and the factors, and analyzed impacts of soil temperature at the 5, 10 and 15 cm depth (T5, T10, T15), soil moisture over the depth of 0-10 cm (Ws), and soil total nitrogen (N), soil total organic carbon (C), ratio of carbon and nitrogen (C/N), soil total sulfur (S), litter fall mass (Lw) and litter fall moisture (Lm) on the spatial heterogeneity of Rs, respectively. We also calculated the minimum sampling number of all the factors at different confidence levels and under the responding estimation accuracy. The results showed that: (1) the spatial heterogeneity of C/N at 4 m sampling scale, Ws at 2 m sampling scale and T10, T15 at 1 m sampling scale had low variability, while the spatial variation of Rs and other related factors had medium variability. Coefficients of variation of Rs, C/N and S decreased with the increase of the sampling scales, but those of N, C, Ws, T₅, T₁₀, T₁₅, Lw and Lm showed contrary trend; (2) the spatial autocorrelation of Rs, Ws, T₅, T₁₀, T₁₅, Lw and Lm decreased with the decrease of sampling scales but the spatial autocorrelation of C, N, C/N increased with the decrease of sampling scales, and the spatial autocorrelation of S decreased with the decrease of the sampling scales at initial stage and then increased; (3) the key factors that influenced the spatial heterogeneity of soil respiration were different at different sampling scales. Soil temperature was the key factor influencing the spatial heterogeneity of Rs at a larger scale. However, at a smaller scale, the spatial heterogeneity of Rs was influenced by C, Lw and Lm; (4) the minimum sampling number for soil respiration measurement and its influencing factors reduced greatly with the decrease of confidence level and responding estimation accuracy. The sampling

  16. [Spatial Heterogeneity of Soil Respiration in a Larch Plantation of North China at Different Sampling Scales].

    PubMed

    Yan, Jun-xia; Liang, Ya-nan; Li, Hong-jian; Li, Jun-jian

    2015-12-01

    Based on observations of soil respiration rate (Rs) and both biotic and abiotic factors in Pangquangou Nature Reserve at three sampling scales (4, 2, and 1 m), we studied the spatial heterogeneity of Rs and the factors, and analyzed impacts of soil temperature at the 5, 10 and 15 cm depth (T5, T10, T15), soil moisture over the depth of 0-10 cm (Ws), and soil total nitrogen (N), soil total organic carbon (C), ratio of carbon and nitrogen (C/N), soil total sulfur (S), litter fall mass (Lw) and litter fall moisture (Lm) on the spatial heterogeneity of Rs, respectively. We also calculated the minimum sampling number of all the factors at different confidence levels and under the responding estimation accuracy. The results showed that: (1) the spatial heterogeneity of C/N at 4 m sampling scale, Ws at 2 m sampling scale and T10, T15 at 1 m sampling scale had low variability, while the spatial variation of Rs and other related factors had medium variability. Coefficients of variation of Rs, C/N and S decreased with the increase of the sampling scales, but those of N, C, Ws, T₅, T₁₀, T₁₅, Lw and Lm showed contrary trend; (2) the spatial autocorrelation of Rs, Ws, T₅, T₁₀, T₁₅, Lw and Lm decreased with the decrease of sampling scales but the spatial autocorrelation of C, N, C/N increased with the decrease of sampling scales, and the spatial autocorrelation of S decreased with the decrease of the sampling scales at initial stage and then increased; (3) the key factors that influenced the spatial heterogeneity of soil respiration were different at different sampling scales. Soil temperature was the key factor influencing the spatial heterogeneity of Rs at a larger scale. However, at a smaller scale, the spatial heterogeneity of Rs was influenced by C, Lw and Lm; (4) the minimum sampling number for soil respiration measurement and its influencing factors reduced greatly with the decrease of confidence level and responding estimation accuracy. The sampling

  17. Effect of almond shell biochar addition on the hydro-physical properties of an arable Central Valley soil

    NASA Astrophysics Data System (ADS)

    Lopez, V.; Ghezzehei, T. A.

    2014-12-01

    Biochar is composed of any carbonaceous matter pyrolyzed under low oxygen exposure. Its use as a soil amendment to address soil infertility has been accelerated by studies reporting positive effects of enhanced nutrient retention, cation exchange capacity, microbial activity, and vegetative growth over time. Biochar has also been considered as a carbon sequestration method because of its reported environmental persistence. While the aforementioned effects are positive benefits of biochar's use, its impact on soil physical properties and water flow are equally important in maintaining soil fertility. This study aims to show how soil physical and hydraulic properties change over time with biochar addition. To address these aims, we conducted a 9 week microcosm incubation experiment with local arable loamy sand soils amended with biochar. Biochar was created from locally collected almond shells and differs by pyrolysis temperatures (350°C, 700°C) and size (<250 μm, 1-2mm). Additionally, biochar was applied to soil at a low (10 t/ha) or high (60 t/ha) rates. Changes in soil water flow properties were analyzed by infiltration or pressure cell experiments immediately after creating our soil-biochar mixtures. These experiments were repeated during and after the incubation period to observe if and how flow is altered over time. Following incubation and hydraulic experiments, a water drop penetration time (WDPT) test was conducted to observe any alterations in surface hydrophobicity. Changes in soil physical properties were analyzed by determining content of water stable aggregates remaining after wet sieving. This series of experiments is expected to provide a greater understanding on the impact biochar addition on soil physical and hydraulic properties. Furthermore, it provides insight into whether or not converting local agricultural waste into biochar for soil use will be beneficial, especially in agricultural systems undergoing climate stress.

  18. Rapid assessment of soil and groundwater tritium by vegetation sampling

    SciTech Connect

    Murphy, C.E. Jr.

    1995-09-01

    A rapid and relatively inexpensive technique for defining the extent of groundwater contamination by tritium has been investigated. The technique uses existing vegetation to sample the groundwater. Water taken up by deep rooted trees is collected by enclosing tree branches in clear plastic bags. Water evaporated from the leaves condenses on the inner surface of the bag. The water is removed from the bag with a syringe. The bags can be sampled many times. Tritium in the water is detected by liquid scintillation counting. The water collected in the bags has no color and counts as well as distilled water reference samples. The technique was used in an area of known tritium contamination and proved to be useful in defining the extent of tritium contamination.

  19. 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

  20. Recovery of Francisella tularensis from soil samples by filtration and detection by real-time PCR and cELISA.

    PubMed

    Sellek, Ricela; Jimenez, Oscar; Aizpurua, Carmen; Fernandez-Frutos, Begoña; De Leon, Patricia; Camacho, Maite; Fernandez-Moreira, Daniel; Ybarra, Carmen; Carlos Cabria, Juan

    2008-03-01

    The aim of this study was to develop a specific and highly sensitive method able to detect very low concentrations of Francisella tularensis in soil samples by real-time PCR (qPCR) with SYBR Green I. tul4 gene, which encodes the 17-kDa protein (TUL4) in F. tularensis strains, was amplified using a LightCycler (LC) device. We achieved a detection limit of 0.69 fg of genomic DNA from F. tularensis subp. holarctica live vaccine strain (LVS), corresponding to a value less than 3.4 genome equivalents per reaction. The qPCR was shown to be specific, highly sensitive and reproducible. In addition, we evaluated 2 new methods for recovering bacteria from soil based on 1-step filtration using glass fiber filters and PVDF filters. These filtration methods enabled us to recover F. tularensis efficiently from soil samples. As few as 50 CFU per 0.5 g of soil were detected by qPCR. Capture enzyme-linked immunosorbent assay (cELISA) allowed us to detect and quantify the amount of bacteria recovered from soil by an immunological method. Although qPCR was more sensitive than cELISA, we did not observe substantial differences in the amount of bacteria quantified by both methods.

  1. Responses of soil microbial communities and enzyme activities to nitrogen and phosphorus additions in Chinese fir plantations of subtropical China

    NASA Astrophysics Data System (ADS)

    Dong, W. Y.; Zhang, X. Y.; Liu, X. Y.; Fu, X. L.; Chen, F. S.; Wang, H. M.; Sun, X. M.; Wen, X. F.

    2015-07-01

    Nitrogen (N) and phosphorus (P) additions to forest ecosystems are known to influence various above-ground properties, such as plant productivity and composition, and below-ground properties, such as soil nutrient cycling. However, our understanding of how soil microbial communities and their functions respond to nutrient additions in subtropical plantations is still not complete. In this study, we added N and P to Chinese fir plantations in subtropical China to examine how nutrient additions influenced soil microbial community composition and enzyme activities. The results showed that most soil microbial properties were responsive to N and/or P additions, but responses often varied depending on the nutrient added and the quantity added. For instance, there were more than 30 % greater increases in the activities of β-Glucosidase (βG) and N-acetyl-β-D-glucosaminidase (NAG) in the treatments that received nutrient additions compared to the control plot, whereas acid phosphatase (aP) activity was always higher (57 and 71 %, respectively) in the P treatment. N and P additions greatly enhanced the PLFA abundanceespecially in the N2P treatment, the bacterial PLFAs (bacPLFAs), fungal PLFAs (funPLFAs) and actinomycic PLFAs (actPLFAs) were about 2.5, 3 and 4 times higher, respectively, than in the CK. Soil enzyme activities were noticeably higher in November than in July, mainly due to seasonal differences in soil moisture content (SMC). βG or NAG activities were significantly and positively correlated with microbial PLFAs. There were also significant relationships between gram-positive (G+) bacteria and all three soil enzymes. These findings indicate that G+ bacteria is the most important microbial community in C, N, and P transformations in Chinese fir plantations, and that βG and NAG would be useful tools for assessing the biogeochemical transformation and metabolic activity of soil microbes. We recommend combined additions of N and P fertilizer to promote soil

  2. Characterization of the geochemical and physical properties of wetland soils on the Savannah River Site: Field sampling activities. Final report

    SciTech Connect

    Dixon, K.L.

    1992-11-01

    There are 36,000 acres of wetlands on the Savannah River Site (SRS) and an additional 5,000 acres of floodplain. Recent studies of wetland soils near various waste sites at SRS have shown that some wetlands have been contaminated with pollutants resulting from SRS operations. In general, releases of contaminants to wetland areas have been indirect. These releases may have originated at disposal lagoons or waste facilities located in the vicinity of the wetland areas. Transport mechanisms such as surface runoff, soil erosion, sediment transport, and groundwater seepage into downgradient wetland areas are responsible for the indirect discharges to the wetland areas. The SRS determined that a database of background geochemical and physical properties for wetland soils on the SRS was needed to facilitate future remedial investigations, human health and ecological risk assessments, treatability studies, and feasibility studies for the wetland areas. These data are needed for comparison to contaminant data collected from wetland soils that have been affected by contamination from SRS operations. This report describes the efforts associated with the collection of soil cores, preparation of a lithologic log for each core, and the processing and packaging of individual soil samples for shipment to analytical laboratory facilities.

  3. Characterization of the geochemical and physical properties of wetland soils on the Savannah River Site: Field sampling activities

    SciTech Connect

    Dixon, K.L. )

    1992-11-01

    There are 36,000 acres of wetlands on the Savannah River Site (SRS) and an additional 5,000 acres of floodplain. Recent studies of wetland soils near various waste sites at SRS have shown that some wetlands have been contaminated with pollutants resulting from SRS operations. In general, releases of contaminants to wetland areas have been indirect. These releases may have originated at disposal lagoons or waste facilities located in the vicinity of the wetland areas. Transport mechanisms such as surface runoff, soil erosion, sediment transport, and groundwater seepage into downgradient wetland areas are responsible for the indirect discharges to the wetland areas. The SRS determined that a database of background geochemical and physical properties for wetland soils on the SRS was needed to facilitate future remedial investigations, human health and ecological risk assessments, treatability studies, and feasibility studies for the wetland areas. These data are needed for comparison to contaminant data collected from wetland soils that have been affected by contamination from SRS operations. This report describes the efforts associated with the collection of soil cores, preparation of a lithologic log for each core, and the processing and packaging of individual soil samples for shipment to analytical laboratory facilities.

  4. Soil characterization by energy dispersive X-ray fluorescence: sampling strategy for in situ analysis.

    PubMed

    Custo, Graciela; Boeykens, Susana; Dawidowski, L; Fox, L; Gómez, D; Luna, F; Vázquez, Cristina

    2005-07-01

    This work describes a sampling strategy that will allow the use of portable EDXRF (energy dispersive X-ray fluorescence) instruments for "in situ" soil analysis. The methodology covers a general approach to planning field investigations for any type of environmental studies and it was applied for a soil characterization study in the zone of Campana, Argentina, by evaluating data coming from an EDXRF spectrometer with a radioisotope excitation source. Simulating non-treated sampled as "in situ" samples and a soil characterization for Campana area was intended. "In situ" EDXRF methodology is a powerful analytical modality with the advantage of providing data immediately, allowing a fast general screening of the soil composition. PMID:16038489

  5. Toxicity of the antimicrobial oxytetracycline to soil organisms in a multi-species-soil system (MS.3) and influence of manure co-addition.

    PubMed

    Boleas, Sara; Alonso, Carmen; Pro, Javier; Fernández, Carlos; Carbonell, Gregoria; Tarazona, Jose V

    2005-07-15

    The effects of oxytetracycline (OTC) on soil organisms have been studied using a multi-species-soil system (MS.3). Oxytetracycline concentrations of 0.01 mg/kg, 1 mg/kg and 100 mg/kg soil were added to the 20 cm top arable soil layer, with and without horse/cow manure (0.15 g organic N/kg soil) co-addition. No mortality was observed for Eisenia foetida S. but significant effects on soil microbial enzymatic activities (phosphatase, dehydrogenase) were observed. The effects on soil microorganism were observed earlier but then recovered in systems with manure co-addition. More important, OTC related plant inhibition was observed in the manured but not in the non-manured systems. Oxytetracycline reached 0.19 and 1.85 mg/l in the leachate of the soil spiked with 1 and 100 mg OTC/kg, respectively and 0.05 and 1.14 mg/l for the same OTC concentrations in the manured systems. The results confirm that manure can modify both the fate and the effects of OTC and that the multi-species-soil systems can reproduce the conditions for a realistic effect estimation of veterinary medicines.

  6. Metallic particles of high cobalt content in Apollo 15 soil samples.

    NASA Technical Reports Server (NTRS)

    Axon, H. J.; Goldstein, J. I.

    1973-01-01

    Single phase alpha-kamacite containing more than 3.2 wt % Co and gamma-taenite containing from 30 to 60 wt % Ni from the Apollo 15 soils - 15031, 15071, 15081, 15261, and 15271 - have been examined by metallographic and electron microprobe techniques. In addition two phase alpha + gamma particles from soils 14003, 15071, 15261, and 15271 with Ni and Co contents well outside the meteoritic range have also been examined. Two distinct types of alpha-gamma structure occur, one analogous to 'clear taenite' in ordinary chondrites, and the other analogous to a 'Widmanstaetten' structure in Ni-rich ataxites. The measured Ni gradients in the two-phase particles are very similar to those meteorites having the same structure. However the Co content is much higher than the meteoritic samples, up to 12 wt % in the alpha phase. Approximate phase equilibria data for the Fe-Ni-Co system indicate equilibration of the two-phase particles during cooling to approximately 350 C. Estimates of cooling rates and second-phase growth times indicate that the maximum time necessary for the development of the high-Co two-phase structures is roughly 25 to 100 m.y. These estimates argue for the development of the two-phase structures during formation of the lunar crust, at a depth of 10 to 20 km beneath the moon's surface.

  7. Methods for preparing comparative standards and field samples for neutron activation analysis of soil

    SciTech Connect

    Glasgow, D.C.; Dyer, F.F.; Robinson, L.

    1994-06-01

    One of the more difficult problems associated with comparative neutron activation analysis (CNAA) is the preparation of standards which are tailor-made to the desired irradiation and counting conditions. Frequently, there simply is not a suitable standard available commercially, or the resulting gamma spectrum is convoluted with interferences. In a recent soil analysis project, the need arose for standards which contained about 35 elements. In response, a computer spreadsheet was developed to calculate the appropriate amount of each element so that the resulting gamma spectrum is relatively free of interferences. Incorporated in the program are options for calculating all of the irradiation and counting parameters including activity produced, necessary flux/bombardment time, counting time, and appropriate source-to-detector distance. The result is multi-element standards for CNAA which have optimal concentrations. The program retains ease of use without sacrificing capability. In addition to optimized standard production, a novel soil homogenization technique was developed which is a low cost, highly efficient alternative to commercially available homogenization systems. Comparative neutron activation analysis for large scale projects has been made easier through these advancements. This paper contains details of the design and function of the NAA spreadsheet and innovative sample handling techniques.

  8. Rapid fusion method for the determination of refractory thorium and uranium isotopes in soil samples

    SciTech Connect

    Maxwell, Sherrod L.; Hutchison, Jay B.; McAlister, Daniel R.

    2015-02-14

    Recently, approximately 80% of participating laboratories failed to accurately determine uranium isotopes in soil samples in the U.S Department of Energy Mixed Analyte Performance Evaluation Program (MAPEP) Session 30, due to incomplete dissolution of refractory particles in the samples. Failing laboratories employed acid dissolution methods, including hydrofluoric acid, to recover uranium from the soil matrix. The failures illustrate the importance of rugged soil dissolution methods for the accurate measurement of analytes in the sample matrix. A new rapid fusion method has been developed by the Savannah River National Laboratory (SRNL) to prepare 1-2 g soil sample aliquots very quickly, with total dissolution of refractory particles. Soil samples are fused with sodium hydroxide at 600 ºC in zirconium crucibles to enable complete dissolution of the sample. Uranium and thorium are separated on stacked TEVA and TRU extraction chromatographic resin cartridges, prior to isotopic measurements by alpha spectrometry on cerium fluoride microprecipitation sources. Plutonium can also be separated and measured using this method. Batches of 12 samples can be prepared for measurement in <5 hours.

  9. Rapid fusion method for the determination of refractory thorium and uranium isotopes in soil samples

    DOE PAGES

    Maxwell, Sherrod L.; Hutchison, Jay B.; McAlister, Daniel R.

    2015-02-14

    Recently, approximately 80% of participating laboratories failed to accurately determine uranium isotopes in soil samples in the U.S Department of Energy Mixed Analyte Performance Evaluation Program (MAPEP) Session 30, due to incomplete dissolution of refractory particles in the samples. Failing laboratories employed acid dissolution methods, including hydrofluoric acid, to recover uranium from the soil matrix. The failures illustrate the importance of rugged soil dissolution methods for the accurate measurement of analytes in the sample matrix. A new rapid fusion method has been developed by the Savannah River National Laboratory (SRNL) to prepare 1-2 g soil sample aliquots very quickly, withmore » total dissolution of refractory particles. Soil samples are fused with sodium hydroxide at 600 ºC in zirconium crucibles to enable complete dissolution of the sample. Uranium and thorium are separated on stacked TEVA and TRU extraction chromatographic resin cartridges, prior to isotopic measurements by alpha spectrometry on cerium fluoride microprecipitation sources. Plutonium can also be separated and measured using this method. Batches of 12 samples can be prepared for measurement in <5 hours.« less

  10. Rapid fusion method for the determination of Pu, Np, and Am in large soil samples

    DOE PAGES

    Maxwell, Sherrod L.; Culligan, Brian; Hutchison, Jay B.; McAlister, Daniel R.

    2015-02-14

    A new rapid sodium hydroxide fusion method for the preparation of 10-20 g soil samples has been developed by the Savannah River National Laboratory (SRNL). The method enables lower detection limits for plutonium, neptunium, and americium in environmental soil samples. The method also significantly reduces sample processing time and acid fume generation compared to traditional soil digestion techniques using hydrofluoric acid. Ten gram soil aliquots can be ashed and fused using the new method in 1-2 hours, completely dissolving samples, including refractory particles. Pu, Np and Am are separated using stacked 2mL cartridges of TEVA and DGA Resin and measuredmore » using alpha spectrometry. The method can be adapted for measurement by inductively-coupled plasma mass spectrometry (ICP-MS). Two 10 g soil aliquots of fused soil may be combined prior to chromatographic separations to further improve detection limits. Total sample preparation time, including chromatographic separations and alpha spectrometry source preparation, is less than 8 hours.« less

  11. Rapid fusion method for the determination of Pu, Np, and Am in large soil samples

    SciTech Connect

    Maxwell, Sherrod L.; Culligan, Brian; Hutchison, Jay B.; McAlister, Daniel R.

    2015-02-14

    A new rapid sodium hydroxide fusion method for the preparation of 10-20 g soil samples has been developed by the Savannah River National Laboratory (SRNL). The method enables lower detection limits for plutonium, neptunium, and americium in environmental soil samples. The method also significantly reduces sample processing time and acid fume generation compared to traditional soil digestion techniques using hydrofluoric acid. Ten gram soil aliquots can be ashed and fused using the new method in 1-2 hours, completely dissolving samples, including refractory particles. Pu, Np and Am are separated using stacked 2mL cartridges of TEVA and DGA Resin and measured using alpha spectrometry. The method can be adapted for measurement by inductively-coupled plasma mass spectrometry (ICP-MS). Two 10 g soil aliquots of fused soil may be combined prior to chromatographic separations to further improve detection limits. Total sample preparation time, including chromatographic separations and alpha spectrometry source preparation, is less than 8 hours.

  12. Bioaccessibility of uranium in soil samples from Port Hope, Ontario, Canada.

    PubMed

    Jovanovic, Slobodan V; Pan, Pujing; Wong, Larry

    2012-08-21

    Adequate assessment of human health risk of uranium contamination at hazardous waste sites, which is an important step in determining the cleanup strategy, is based on bioavailability data. Bioavailability of uranium from contaminated soil has not been properly determined yet. Bioaccessibility is an in vitro conservative estimate of bioavailability and is thus frequently used for site-specific risk assessment. Bioaccessibility of uranium was measured in 33 soil samples from the Port Hope area in Ontario, Canada, by the physiologically based extraction test (PBET). Higher bioaccessibility values in the gastric plus intestinal phase, 48.4% ± 16.8%, than in the gastric phase, 20.8% ± 11.7%, are very probably the result of more efficient extraction of uranium from soil by intestinal fluid rich in carbonate ions. The observed variability of measured bioaccessibility values is discussed in light of the results of scanning electron microscope examination of the soil samples. Uranium bioaccessibility values in both gastric (acidic) and gastric plus intestinal (neutral) phases are higher in soil samples with smaller uranium-bearing particles and lower in samples where the uranium-bearing particles are larger. We postulate that the most important reason for variability of measured bioaccessibility values in Port Hope soil samples may be the difference in particle size of uranium-bearing particles.

  13. Spatial Variation of Soil Lead in an Urban Community Garden: Implications for Risk-Based Sampling.

    PubMed

    Bugdalski, Lauren; Lemke, Lawrence D; McElmurry, Shawn P

    2014-01-01

    Soil lead pollution is a recalcitrant problem in urban areas resulting from a combination of historical residential, industrial, and transportation practices. The emergence of urban gardening movements in postindustrial cities necessitates accurate assessment of soil lead levels to ensure safe gardening. In this study, we examined small-scale spatial variability of soil lead within a 15 × 30 m urban garden plot established on two adjacent residential lots located in Detroit, Michigan, USA. Eighty samples collected using a variably spaced sampling grid were analyzed for total, fine fraction (less than 250 μm), and bioaccessible soil lead. Measured concentrations varied at sampling scales of 1-10 m and a hot spot exceeding 400 ppm total soil lead was identified in the northwest portion of the site. An interpolated map of total lead was treated as an exhaustive data set, and random sampling was simulated to generate Monte Carlo distributions and evaluate alternative sampling strategies intended to estimate the average soil lead concentration or detect hot spots. Increasing the number of individual samples decreases the probability of overlooking the hot spot (type II error). However, the practice of compositing and averaging samples decreased the probability of overestimating the mean concentration (type I error) at the expense of increasing the chance for type II error. The results reported here suggest a need to reconsider U.S. Environmental Protection Agency sampling objectives and consequent guidelines for reclaimed city lots where soil lead distributions are expected to be nonuniform. PMID:23614628

  14. [Effects of water levels and the additions of different nitrogen forms on soil net nitrogen transformation rate and N2O emission in subtropical forest soils].

    PubMed

    Ma, Fen; Ma, Hong-liang; Qiu, Hong; Yang, Hong-yu

    2015-02-01

    An incubation experiment was conducted to investigate the effects of the additions of different nitrogen forms on nitrogen transformation in red soils of subtropical forest under soil moisture conditions with 40%, 70% and 110% of water holding capacity (WHC). The results showed that soil net mineralization and ammonification rates were maximum at 70% WHC and minimum at 40% WHC. Compared with the control, the addition of NO(3-)-N decreased the soil net mineralization and ammonification rates by 56.1% and 43.0% under 70% WHC condition, and decreased by 68.2% and 19.0% under 110% WHC, respectively. However, the proportion of ammonification to mineralization increased at 70% and 110% WHC, which suggested that nitrate addition inhibited the nitrification. With addition of NO(3-)-N at 110% WHC, the net nitrification rate was lowest while N20 emission was highest with the concomitant decrease of nitrate content, indicating that N2O emission was largely derived from denitrification. However, at 40% WHC and 70% WHC, the maximum N20 flux was found at the early stage of incubation. Even with addition of NH(4+)-N and NO(3-)-N, N2O flux did not change much at the latter stage of incubation, indicating that autotrophic nitrification was dominant for N20 production at the early stage of incubation. Under 40% WHC condition, soluble organic carbon increased more and it increased largely with NH(4+)-N addition, which meant NH(4+)-N addition could enhance the mineralization of soil organic matter. Under 40% and 110% WHC conditions, the addition of NH(4+)-N increased significantly the soil soluble organic nitrogen (SON) by 73.6% and 176.6% compared with the control, respectively. A significant increase of 78.7% for SON was only found at 40% WHC under addition of NO(3-)-N compared with the control. These results showed that high soil moisture condition and addition of NH(4+)-N were of benefit to SON formation.

  15. Soil pore-gas sampling by photoacoustic radiometry

    SciTech Connect

    Sollid, J.E.

    1994-11-01

    Concentrations of volatile organics in a soil pore-gas plume were measured using a commercially available multigas monitor. The monitor is a photoacoustic radiometer (PAR) controlled by an on-board, programmable microprocessor. The measurements determine the extent and location of the vapor plume in the subsurface. At least twelve wells surrounding the sources are measured quarterly. The sources are located in former liquid chemical waste disposal pits and shafts at Los Alamos National Laboratory. The primary constituents of the plume are 1,1,1 trichloroethane (TCA), trichloroethene (TCE), and tetrachloroethene or perchloroethene or perchloroethene (PCE). Four quarters of data are presented for TCA. All were used primarily as solvents and degreasers. Previously the composition of the vapor plume was determined by Gas Chromatography Mass Spectrometer GCMS methods. Photoacoustic radiometry and gas chromatography are discussed giving the advantages and disadvantages of each method, although in this program they are basically complementary. Gas chromatography is a more qualitative method to determine which analytes are present and the approximate concentration. Photoacoustic radiometry, to function well, requires foreknowledge of constituents and serves best to determine how much is present. Measurements are quicker and more direct with photoacoustic methods. Once the constituents to be measured are known, the cost to monitor is much less using photoacoustics, and the results are available more quickly.

  16. ECa-Directed Soil Sampling for Characterizing Spatial Variability: Monitoring Management- Induced Change

    NASA Astrophysics Data System (ADS)

    Corwin, D. L.

    2006-05-01

    Characterizing spatial variability is an important consideration of any landscape-scale soil-related problem. Geospatial measurements of apparent soil electrical conductivity (ECa) are useful for characterizing spatial variability by directing soil sampling. The objective of this presentation is to discuss equipment, protocols, sampling designs, and a case study of an ECa survey to characterize spatial variability. Specifically, a preliminary spatio-temporal study of management-induced changes to soil quality will be demonstrated for a drainage water reuse study site. The spatio-temporal study used electromagnetic induction ECa data and a response surface sampling design to select 40 sites that reflected the spatial variability of soil properties (i.e., salinity, Na levels, Mo, and B) impacting the intended agricultural use of a saline-sodic field in California's San Joaquin Valley. Soil samples were collected in August 1999 and April 2002. Data from 1999 indicate the presence of high salinity, which increased with depth, high sodium adsorption ratio (SAR), which also increased with depth, and moderate to high B and Mo, which showed no specific trends with depth. The application of drainage water for 32 months resulted in leaching of B from the top 0.3 of soil, leaching of salinity from the top 0.6 m of soil, and leaching of Na and Mo from the top 1.2 m of soil. The leaching fraction over the time period from 1999-2002 was estimated to be 0.10. The level of salinity in the reused drainage water (i.e., 3-5 dS/m) allowed infiltration and leaching to occur even though high sodium and high expanding-lattice clay levels posed potential water flow problems. The leaching of salinity, Na, Mo, and B has resulted in increased forage yield and improved quality of those yields. Preliminary spatio-temporal analyses indicate at least short-term feasibility of drainage water reuse from the perspective of soil quality when the goal is forage production for grazing livestock. The

  17. Exploring effective sampling design for monitoring soil organic carbon in degraded Tibetan grasslands.

    PubMed

    Chang, Xiaofeng; Bao, Xiaoying; Wang, Shiping; Zhu, Xiaoxue; Luo, Caiyun; Zhang, Zhenhua; Wilkes, Andreas

    2016-05-15

    The effects of climate change and human activities on grassland degradation and soil carbon stocks have become a focus of both research and policy. However, lack of research on appropriate sampling design prevents accurate assessment of soil carbon stocks and stock changes at community and regional scales. Here, we conducted an intensive survey with 1196 sampling sites over an area of 190 km(2) of degraded alpine meadow. Compared to lightly degraded meadow, soil organic carbon (SOC) stocks in moderately, heavily and extremely degraded meadow were reduced by 11.0%, 13.5% and 17.9%, respectively. Our field survey sampling design was overly intensive to estimate SOC status with a tolerable uncertainty of 10%. Power analysis showed that the optimal sampling density to achieve the desired accuracy would be 2, 3, 5 and 7 sites per 10 km(2) for lightly, moderately, heavily and extremely degraded meadows, respectively. If a subsequent paired sampling design with the optimum sample size were performed, assuming stock change rates predicted by experimental and modeling results, we estimate that about 5-10 years would be necessary to detect expected trends in SOC in the top 20 cm soil layer. Our results highlight the utility of conducting preliminary surveys to estimate the appropriate sampling density and avoid wasting resources due to over-sampling, and to estimate the sampling interval required to detect an expected sequestration rate. Future studies will be needed to evaluate spatial and temporal patterns of SOC variability.

  18. Enhancement of carbon sequestration in soil in the temperature grasslands of northern China by addition of nitrogen and phosphorus.

    PubMed

    He, Nianpeng; Yu, Qiang; Wang, Ruomeng; Zhang, Yunhai; Gao, Yang; Yu, Guirui

    2013-01-01

    Increased nitrogen (N) deposition is common worldwide. Questions of where, how, and if reactive N-input influences soil carbon (C) sequestration in terrestrial ecosystems are of great concern. To explore the potential for soil C sequestration in steppe region under N and phosphorus (P) addition, we conducted a field experiment between 2006 and 2012 in the temperate grasslands of northern China. The experiment examined 6 levels of N (0-56 g N m(-2) yr(-1)), 6 levels of P (0-12.4 g P m(-2) yr(-1)), and a control scenario. Our results showed that addition of both N and P enhanced soil total C storage in grasslands due to significant increases of C input from litter and roots. Compared with control plots, soil organic carbon (SOC) in the 0-100 cm soil layer varied quadratically, from 156.8 to 1352.9 g C m(-2) with N addition gradient (R(2) = 0.99, P < 0.001); and logarithmically, from 293.6 to 788.6 g C m(-2) with P addition gradient (R(2) = 0.56, P = 0.087). Soil inorganic carbon (SIC) decreased quadratically with N addition. The net C sequestration on grassland (including plant, roots, SIC, and SOC) increased linearly from -128.6 to 729.0 g C m(-2) under N addition (R(2) = 0.72, P = 0.023); and increased logarithmically, from 248.5 to 698 g C m(-2)under P addition (R(2) = 0.82, P = 0.014). Our study implies that N addition has complex effects on soil carbon dynamics, and future studies of soil C sequestration on grasslands should include evaluations of both SOC and SIC under various scenarios.

  19. Soil microbial responses to forest floor litter manipulation and nitrogen addition in a mixed-wood forest of northern China

    PubMed Central

    Sun, Xiao-Lu; Zhao, Jing; You, Ye-Ming; Jianxin Sun, Osbert

    2016-01-01

    Changes in litterfall dynamics and soil properties due to anthropogenic or natural perturbations have important implications to soil carbon (C) and nutrient cycling via microbial pathway. Here we determine soil microbial responses to contrasting types of litter inputs (leaf vs. fine woody litter) and nitrogen (N) deposition by conducting a multi-year litter manipulation and N addition experiment in a mixed-wood forest. We found significantly higher soil organic C, total N, microbial biomass C (MBC) and N (MBN), microbial activity (MR), and activities of four soil extracellular enzymes, including β-glucosidase (BG), N-acetyl-β-glucosaminidase (NAG), phenol oxidase (PO), and peroxidase (PER), as well as greater total bacteria biomass and relative abundance of gram-negative bacteria (G-) community, in top soils of plots with presence of leaf litter than of those without litter or with presence of only fine woody litter. No apparent additive or interactive effects of N addition were observed in this study. The occurrence of more labile leaf litter stimulated G-, which may facilitate microbial community growth and soil C stabilization as inferred by findings in literature. A continued treatment with contrasting types of litter inputs is likely to result in divergence in soil microbial community structure and function. PMID:26762490

  20. Spatial prediction of Soil Organic Carbon contents in croplands, grasslands and forests using environmental covariates and Generalized Additive Models (Southern Belgium)

    NASA Astrophysics Data System (ADS)

    Chartin, Caroline; Stevens, Antoine; van Wesemael, Bas

    2015-04-01

    Providing spatially continuous Soil Organic Carbon data (SOC) is needed to support decisions regarding soil management, and inform the political debate with quantified estimates of the status and change of the soil resource. Digital Soil Mapping techniques are based on relations existing between a soil parameter (measured at different locations in space at a defined period) and relevant covariates (spatially continuous data) that are factors controlling soil formation and explaining the spatial variability of the target variable. This study aimed at apply DSM techniques to recent SOC content measurements (2005-2013) in three different landuses, i.e. cropland, grassland, and forest, in the Walloon region (Southern Belgium). For this purpose, SOC databases of two regional Soil Monitoring Networks (CARBOSOL for croplands and grasslands, and IPRFW for forests) were first harmonized, totalising about 1,220 observations. Median values of SOC content for croplands, grasslands, and forests, are respectively of 12.8, 29.0, and 43.1 g C kg-1. Then, a set of spatial layers were prepared with a resolution of 40 meters and with the same grid topology, containing environmental covariates such as, landuses, Digital Elevation Model and its derivatives, soil texture, C factor, carbon inputs by manure, and climate. Here, in addition to the three classical texture classes (clays, silt, and sand), we tested the use of clays + fine silt content (particles < 20 µm and related to stable carbon fraction) as soil covariate explaining SOC variations. For each of the three land uses (cropland, grassland and forest), a Generalized Additive Model (GAM) was calibrated on two thirds of respective dataset. The remaining samples were assigned to a test set to assess model performance. A backward stepwise procedure was followed to select the relevant environmental covariates using their approximate p-values (the level of significance was set at p < 0.05). Standard errors were estimated for each of

  1. Measuring environmental change in forest ecosystems by repeated soil sampling: a North American perspective

    USGS Publications Warehouse

    Lawrence, Gregory B.; Fernandez, Ivan J.; Richter, Daniel D.; Ross, Donald S.; Hazlett, Paul W.; Bailey, Scott W.; Oiumet, Rock; Warby, Richard A.F.; Johnson, Arthur H.; Lin, Henry; Kaste, James M.; Lapenis, Andrew G.; Sullivan, Timothy J.

    2013-01-01

    Environmental change is monitored in North America through repeated measurements of weather, stream and river flow, air and water quality, and most recently, soil properties. Some skepticism remains, however, about whether repeated soil sampling can effectively distinguish between temporal and spatial variability, and efforts to document soil change in forest ecosystems through repeated measurements are largely nascent and uncoordinated. In eastern North America, repeated soil sampling has begun to provide valuable information on environmental problems such as air pollution. This review synthesizes the current state of the science to further the development and use of soil resampling as an integral method for recording and understanding environmental change in forested settings. The origins of soil resampling reach back to the 19th century in England and Russia. The concepts and methodologies involved in forest soil resampling are reviewed and evaluated through a discussion of how temporal and spatial variability can be addressed with a variety of sampling approaches. Key resampling studies demonstrate the type of results that can be obtained through differing approaches. Ongoing, large-scale issues such as recovery from acidification, long-term N deposition, C sequestration, effects of climate change, impacts from invasive species, and the increasing intensification of soil management all warrant the use of soil resampling as an essential tool for environmental monitoring and assessment. Furthermore, with better awareness of the value of soil resampling, studies can be designed with a long-term perspective so that information can be efficiently obtained well into the future to address problems that have not yet surfaced.

  2. Measuring environmental change in forest ecosystems by repeated soil sampling: a north american perspective.

    PubMed

    Lawrence, Gregory B; Fernandez, Ivan J; Richter, Daniel D; Ross, Donald S; Hazlett, Paul W; Bailey, Scott W; Ouimet, Rock; Warby, Richard A F; Johnson, Arthur H; Lin, Henry; Kaste, James M; Lapenis, Andrew G; Sullivan, Timothy J

    2013-01-01

    Environmental change is monitored in North America through repeated measurements of weather, stream and river flow, air and water quality, and most recently, soil properties. Some skepticism remains, however, about whether repeated soil sampling can effectively distinguish between temporal and spatial variability, and efforts to document soil change in forest ecosystems through repeated measurements are largely nascent and uncoordinated. In eastern North America, repeated soil sampling has begun to provide valuable information on environmental problems such as air pollution. This review synthesizes the current state of the science to further the development and use of soil resampling as an integral method for recording and understanding environmental change in forested settings. The origins of soil resampling reach back to the 19th century in England and Russia. The concepts and methodologies involved in forest soil resampling are reviewed and evaluated through a discussion of how temporal and spatial variability can be addressed with a variety of sampling approaches. Key resampling studies demonstrate the type of results that can be obtained through differing approaches. Ongoing, large-scale issues such as recovery from acidification, long-term N deposition, C sequestration, effects of climate change, impacts from invasive species, and the increasing intensification of soil management all warrant the use of soil resampling as an essential tool for environmental monitoring and assessment. Furthermore, with better awareness of the value of soil resampling, studies can be designed with a long-term perspective so that information can be efficiently obtained well into the future to address problems that have not yet surfaced. PMID:23673928

  3. Chemical and particle-size evidence for addition of fine dust to soils of the midwestern United States

    NASA Astrophysics Data System (ADS)

    Mason, Joseph A.; Jacobs, Peter M.

    1998-12-01

    Significant long-term atmospheric dust additions to soils are well documented in many parts of the world, but not in the midwestern United States. We investigated elemental mass fluxes associated with soil development in late Wisconsinan loess in Illinois and Minnesota, using Zr as a stable index element. Positive mass fluxes of Al, Fe, and Ti can most plausibly be explained by additions to these soils of fine far-traveled dust, with higher Al/Zr, Fe/Zr, and Ti/Zr ratios than the coarser locally derived loess. High-resolution particle-size analyses support this explanation. The proposed dust influx will complicate efforts to quantify weathering processes in these soils. Far-traveled dust influx could have occurred simultaneously with the final phase of local loess deposition, and/or later, in the Holocene. Depending on the timing of dust influx, many other soils of the region may have been affected by it.

  4. Responses of soil nitrogen fixation to Spartina alterniflora invasion and nitrogen addition in a Chinese salt marsh.

    PubMed

    Huang, Jingxin; Xu, Xiao; Wang, Min; Nie, Ming; Qiu, Shiyun; Wang, Qing; Quan, Zhexue; Xiao, Ming; Li, Bo

    2016-02-12

    Biological nitrogen fixation (BNF) is the major natural process of nitrogen (N) input to ecosystems. To understand how plant invasion and N enrichment affect BNF, we compared soil N-fixation rates and N-fixing microbes (NFM) of an invasive Spartina alterniflora community and a native Phragmites australis community in the Yangtze River estuary, with and without N addition. Our results indicated that plant invasion relative to N enrichment had a greater influence on BNF. At each N level, the S. alterniflora community had a higher soil N-fixation rate but a lower diversity of the nifH gene in comparison with the native community. The S. alterniflora community with N addition had the highest soil N-fixation rate and the nifH gene abundance across all treatments. Our results suggest that S. alterniflora invasion can increase soil N fixation in the high N-loading estuarine ecosystem, and thus may further mediate soil N availability.

  5. Responses of soil nitrogen fixation to Spartina alterniflora invasion and nitrogen addition in a Chinese salt marsh

    PubMed Central

    Huang, Jingxin; Xu, Xiao; Wang, Min; Nie, Ming; Qiu, Shiyun; Wang, Qing; Quan, Zhexue; Xiao, Ming; Li, Bo

    2016-01-01

    Biological nitrogen fixation (BNF) is the major natural process of nitrogen (N) input to ecosystems. To understand how plant invasion and N enrichment affect BNF, we compared soil N-fixation rates and N-fixing microbes (NFM) of an invasive Spartina alterniflora community and a native Phragmites australis community in the Yangtze River estuary, with and without N addition. Our results indicated that plant invasion relative to N enrichment had a greater influence on BNF. At each N level, the S. alterniflora community had a higher soil N-fixation rate but a lower diversity of the nifH gene in comparison with the native community. The S. alterniflora community with N addition had the highest soil N-fixation rate and the nifH gene abundance across all treatments. Our results suggest that S. alterniflora invasion can increase soil N fixation in the high N-loading estuarine ecosystem, and thus may further mediate soil N availability. PMID:26869197

  6. Effect of chronic nitrogen additions on soil nitrogen fractions in red spruce stands

    USGS Publications Warehouse

    David, M.B.; Cupples, A.M.; Lawrence, G.B.; Shi, G.; Vogt, K.; Wargo, P.M.

    1998-01-01

    The responses of temperate and boreal forest ecosystems to increased nitrogen (N) inputs have been varied, and the responses of soil N pools have been difficult to measure. In this study, fractions and pool sizes of N were determined in the forest floor of red spruce stands at four sites in the northeastern U.S. to evaluate the effect of increased N inputs on forest floor N. Two of the stands received 100 kg N ha-1 yr-1 for three years, one stand received 34 kg N ha-1 yr-1 for six years, and the remaining stand received only ambient N inputs. No differences in total N content or N fractions were measured in samples of the Oie and Oa horizons between treated and control plots in the three sites that received N amendments. The predominant N fraction in these samples was amino acid N (31-45 % of total N), followed by hydrolyzable unidentified N (16-31% of total N), acid- soluble N (18-22 % of total N), and NH4/+-N (9-13 % of total N). Rates of atmospheric deposition varied greatly among the four stands. Ammonium N and amino acid N concentrations in the Oie horizon were positively related to wet N deposition, with respective r2 values of 0.92 and 0.94 (n = 4, p < 0.05). These relationships were somewhat stronger than that observed between atmospheric wet N deposition and total N content of the forest floor, suggesting that these pools retain atmospherically deposited N. The NH4/+- N pool may represent atmospherically deposited N that is incorporated into organic matter, whereas the amino acid N pool could result from microbial immobilization of atmospheric N inputs. The response of forest floor N pools to applications of N may be masked, possibly by the large soil N pool, which has been increased by the long-term input of N from atmospheric deposition, thereby overwhelming the short-term treatments.

  7. Validation of Bayesian kriging of arsenic, chromium, lead and mercury surface soil concentrations based on internode sampling

    PubMed Central

    Aelion, C.M.; Davis, H.T.; Liu, Y.; Lawson, A.B.; McDermott, S.

    2009-01-01

    Bayesian kriging is a useful tool for estimating spatial distributions of metals; however, estimates are generally only verified statistically. In this study surface soil samples were collected on a uniform grid and analyzed for As, Cr, Pb, and Hg. The data were interpolated at individual locations by Bayesian kriging. Estimates were validated using a leave-one-out cross validation (LOOCV) statistical method which compared the measured and LOOCV predicted values. Validation also was carried out using additional field sampling of soil metal concentrations at points between original sampling locations, which were compared to kriging prediction distributions. LOOCV results suggest that Bayesian kriging was a good predictor of metal concentrations. When measured internode metal concentrations and estimated kriged values were compared, the measured values were located within the 5th – 95th percentile prediction distributions in over half of the internode locations. Estimated and measured internode concentrations were most similar for As and Pb. Kriged estimates did not compare as well to measured values for concentrations below the analytical minimum detection limit, or for internode samples that were very close to the original sampling node. Despite inherent variability in metal concentrations in soils, the kriged estimates were validated statistically and by in situ measurement. PMID:19603658

  8. Identification and Genotyping of Mycobacterium tuberculosis Isolated From Water and Soil Samples of a Metropolitan City

    PubMed Central

    Velayati, Ali Akbar; Farnia, Parissa; Mozafari, Mohadese; Malekshahian, Donya; Farahbod, Amir Masoud; Seif, Shima; Rahideh, Snaz

    2015-01-01

    BACKGROUND: The potential role of environmental Mycobacterium tuberculosis in the epidemiology of TB remains unknown. We investigated the transmission of M tuberculosis from humans to the environment and the possible transmission of M tuberculosis from the environment to humans. METHODS: A total of 1,500 samples were collected from three counties of the Tehran, Iran metropolitan area from February 2012 to January 2014. A total of 700 water samples (47%) and 800 soil samples (53%) were collected. Spoligotyping and the mycobacterial interspersed repetitive units-variable number of tandem repeats typing method were performed on DNA extracted from single colonies. Genotypes of M tuberculosis strains isolated from the environment were compared with the genotypes obtained from 55 patients with confirmed pulmonary TB diagnosed during the study period in the same three counties. RESULTS: M tuberculosis was isolated from 11 of 800 soil samples (1%) and 71 of 700 water samples (10%). T family (56 of 82, 68%) followed by Delhi/CAS (11 of 82, 13.4%) were the most frequent M tuberculosis superfamilies in both water and soil samples. Overall, 27.7% of isolates in clusters were related. No related typing patterns were detected between soil, water, and clinical isolates. The most frequent superfamily of M tuberculosis in clinical isolates was Delhi/CAS (142, 30.3%) followed by NEW-1 (127, 27%). The bacilli in contaminated soil (36%) and damp water (8.4%) remained reculturable in some samples up to 9 months. CONCLUSIONS: Although the dominant M tuberculosis superfamilies in soil and water did not correspond to the dominant M tuberculosis family in patients, the presence of circulating genotypes of M tuberculosis in soil and water highlight the risk of transmission. PMID:25340935

  9. Aeromicrobium halotolerans sp. nov., isolated from desert soil sample.

    PubMed

    Yan, Zheng-Fei; Lin, Pei; Chu, Xiao; Kook, MooChang; Li, Chang-Tian; Yi, Tae-Hoo

    2016-07-01

    A Gram-positive, aerobic, and non-motile, rod-shaped actinomycete strain, designated YIM Y47(T), was isolated from soils collected from Turpan desert, China, and subjected to a polyphasic taxonomic study. Phylogenetic analysis indicated that strain YIM Y47(T) belonged to the genus Aeromicrobium. YIM Y47(T) shared highest 16S rRNA gene sequence similarities with Aeromicrobium massiliense JC14(T) (96.47 %). Growth occurs at 20-45 °C (optimum at 30 °C), pH 6.0-8.0 (optimum at pH 7.0), and salinities of 0-7.0 % NaCl (optimum at 4.0 %). The strain YIM Y47(T) exhibits chemotaxonomic features with menaquinone-7 (MK-7) as the predominant quinone, C16:0, C18:1 ω9c and 10-methyl C18:0 (>10 %) as major fatty acids. The cell-wall peptidoglycan of strain YIM Y47(T) contained LL-diaminopimelic acid as the diagnostic diamino acid. The polar lipids were found to consist of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, and unknown phospholipids. The G+C content of the genomic DNA of strain YIM Y47(T) was found to be 44.7 mol%. On the basis of phylogenetic analyses and phenotypic data, it is proposed that strain YIM Y47(T) should be classified as representing a novel species of the genus Aeromicrobium, with the name Aeromicrobium halotolerans sp. nov. The type strain is YIM Y47(T) (=KCTC 39113(T)=CGMCC 1.15063(T)=DSM 29939(T)=JCM 30627(T)).

  10. Sample preparation and characterization for a study of environmentally acceptable endpoints for hydrocarbon-contaminated soil

    SciTech Connect

    Kreitinger, J.P.; Finn, J.T.

    1995-12-31

    In the past, the interdisciplinary research effort required to investigate the acceptable cleanup endpoints for hydrocarbon-impacted soils has been limited by the lack of standardized soils for testing. To support the efforts of the various researchers participating in the EAE research initiative, soil samples were collected from ten sites representing hydrocarbon-impacted soils typical of exploration/production, refinery, and bulk storage terminal operations. The hydrocarbons in the standard soils include crude oil, mixed refinery products, diesel, gasoline, and jet fuel. Physical characterization included analysis of soil texture, water retention, particle density, nanoporosity, pH, electrical conductivity, cation exchange capacity, buffer capacity, organic carbon, sodium adsorption ratio, and clay mineralogy. Chemical characterization included analysis of total recoverable petroleum hydrocarbons, total volatile and semivolatile organic compounds and metals, and TCLP for metals and organics. An analysis of the aliphatic and aromatic hydrocarbon fractions was performed on each soil to support the use of various models for assessing soil toxicity. Screening-level toxicity tests were conducted using Microtox{trademark}, plant seed germination and growth, and earthworm mortality and growth. Biodegradability screening tests were performed in slurry shake flasks to estimate the availability of hydrocarbon fractions to soil microorganisms.

  11. Taxonomic and functional profiles of soil samples from Atlantic forest and Caatinga biomes in northeastern Brazil

    PubMed Central

    Pacchioni, Ralfo G; Carvalho, Fabíola M; Thompson, Claudia E; Faustino, André L F; Nicolini, Fernanda; Pereira, Tatiana S; Silva, Rita C B; Cantão, Mauricio E; Gerber, Alexandra; Vasconcelos, Ana T R; Agnez-Lima, Lucymara F

    2014-01-01

    Although microorganisms play crucial roles in ecosystems, metagenomic analyses of soil samples are quite scarce, especially in the Southern Hemisphere. In this work, the microbial diversity of soil samples from an Atlantic Forest and Caatinga was analyzed using a metagenomic approach. Proteobacteria and Actinobacteria were the dominant phyla in both samples. Among which, a significant proportion of stress-resistant bacteria associated to organic matter degradation was found. Sequences related to metabolism of amino acids, nitrogen, and DNA and stress resistance were more frequent in Caatinga soil, while the forest sample showed the highest occurrence of hits annotated in phosphorous metabolism, defense mechanisms, and aromatic compound degradation subsystems. The principal component analysis (PCA) showed that our samples are close to the desert metagenomes in relation to taxonomy, but are more similar to rhizosphere microbiota in relation to the functional profiles. The data indicate that soil characteristics affect the taxonomic and functional distribution; these characteristics include low nutrient content, high drainage (both are sandy soils), vegetation, and exposure to stress. In both samples, a rapid turnover of organic matter with low greenhouse gas emission was suggested by the functional profiles obtained, reinforcing the importance of preserving natural areas. PMID:24706600

  12. Automated microbial metabolism laboratory. [design of advanced labeled release experiment based on single addition of soil and multiple sequential additions of media into test chambers

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The design and rationale of an advanced labeled release experiment based on single addition of soil and multiple sequential additions of media into each of four test chambers are outlined. The feasibility for multiple addition tests was established and various details of the methodology were studied. The four chamber battery of tests include: (1) determination of the effect of various atmospheric gases and selection of that gas which produces an optimum response; (2) determination of the effect of incubation temperature and selection of the optimum temperature for performing Martian biochemical tests; (3) sterile soil is dosed with a battery of C-14 labeled substrates and subjected to experimental temperature range; and (4) determination of the possible inhibitory effects of water on Martian organisms is performed initially by dosing with 0.01 ml and 0.5 ml of medium, respectively. A series of specifically labeled substrates are then added to obtain patterns in metabolic 14CO2 (C-14)O2 evolution.

  13. Nitrogen and phosphorus addition impact soil N2O emission in a secondary tropical forest of South China

    PubMed Central

    Wang, Faming; Li, Jian; Wang, Xiaoli; Zhang, Wei; Zou, Bi; Neher, Deborah A.; Li, Zhian

    2014-01-01

    Nutrient availability greatly regulates ecosystem processes and functions of tropical forests. However, few studies have explored impacts of N addition (aN), P addition (aP) and N×P interaction on tropical forests N2O fluxes. We established an N and P addition experiment in a tropical forest to test whether: (1) N addition would increase N2O emission and nitrification, and (2) P addition would increase N2O emission and N transformations. Nitrogen and P addition had no effect on N mineralization and nitrification. Soil microbial biomass was increased following P addition in wet seasons. aN increased 39% N2O emission as compared to control (43.3 μgN2O-N m−2h−1). aP did not increase N2O emission. Overall, N2O emission was 60% greater for aNP relative to the control, but significant difference was observed only in wet seasons, when N2O emission was 78% greater for aNP relative to the control. Our results suggested that increasing N deposition will enhance soil N2O emission, and there would be N×P interaction on N2O emission in wet seasons. Given elevated N deposition in future, P addition in this tropical soil will stimulate soil microbial activities in wet seasons, which will further enhance soil N2O emission. PMID:25001013

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

    PubMed Central

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

    2015-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-11-01

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

  16. Responses of soil microbial communities and enzyme activities to nitrogen and phosphorus additions in Chinese fir plantations of subtropical China

    NASA Astrophysics Data System (ADS)

    Dong, W. Y.; Zhang, X. Y.; Liu, X. Y.; Fu, X. L.; Chen, F. S.; Wang, H. M.; Sun, X. M.; Wen, X. F.

    2015-09-01

    Nitrogen (N) and phosphorus (P) additions to forest ecosystems are known to influence various above-ground properties, such as plant productivity and composition, and below-ground properties, such as soil nutrient cycling. However, our understanding of how soil microbial communities and their functions respond to nutrient additions in subtropical plantations is still not complete. In this study, we added N and P to Chinese fir plantations in subtropical China to examine how nutrient additions influenced soil microbial community composition and enzyme activities. The results showed that most soil microbial properties were responsive to N and/or P additions, but responses often varied depending on the nutrient added and the quantity added. For instance, there were more than 30 % greater increases in the activities of β-glucosidase (βG) and N-acetyl-β-D-glucosaminidase (NAG) in the treatments that received nutrient additions compared to the control plot, whereas acid phosphatase (aP) activity was always higher (57 and 71 %, respectively) in the P treatment. N and P additions greatly enhanced the phospholipid fatty acids (PLFAs) abundance especially in the N2P (100 kg ha-1 yr-1 of N +50 kg ha-1 yr-1 of P) treatment; the bacterial PLFAs (bacPLFAs), fungal PLFAs (funPLFAs) and actinomycic PLFAs (actPLFAs) were about 2.5, 3 and 4 times higher, respectively, than in the CK (control). Soil enzyme activities were noticeably higher in November than in July, mainly due to seasonal differences in soil moisture content (SMC). βG or NAG activities were significantly and positively correlated with microbial PLFAs. These findings indicate that βG and NAG would be useful tools for assessing the biogeochemical transformation and metabolic activity of soil microbes. We recommend combined additions of N and P fertilizer to promote soil fertility and microbial activity in this kind of plantation.

  17. Phosphorus applications improved the soil microbial responses under nitrogen additions in Chinese fir plantations of subtropical China

    NASA Astrophysics Data System (ADS)

    Zhang, Xinyu; Li, Dandan; Yang, Yang; Tang, Yuqian; Wang, Huimin; Chen, Fusheng; Sun, Xiaomin

    2016-04-01

    Nitrogen (N) deposition and low soil phosphorus (P) content aggravate the P limitation in subtropical forest soils. However, the responses of soil microbial communities, enzyme kinetics, and N cycling genes to P additions in subtropical plantations are still not clear. The hypothesis that P application can alleviate the limitation and improve the soil microbial properties was tested by long term field experiment in the Chinese fir plantations in subtropical China. Thirty 20m×20m plots were established in November 2011 and six different treatments were randomly distributed with five replicates. The treatments are control (CK, no N and P application), low N addition (N1: 50 kg N ha-1 yr-1), high N addition (N2: 100 kg N ha-1 yr-1), P addition (P: 50 kg P ha-1 yr-1), low N and P addition (N1P: 50 kg N ha-1 yr-1 and 50 kg P ha-1 yr-1) and high N and P addition (N2P: 100 kg N ha-1 yr-1 and 50 kg P ha-1 yr-1). A suite of responses of soil microorganism across four years (2012-2015) during three seasons (spring, summer and autumn) were measured. Following 4 years of N amendments, fertilized soils were more acidic and had lower soil microbial biomass carbon contents than CK. However, P alleviated the soil acidification and increased the soil microbial biomass carbon contents. Increases in microbial PLFA biomarkers and exoenzyme kinetics in N fertilized plots were observed in the initial year (2013) but reduced since then (2014 and 2015). Whereas P amendments increased the soil PLFA biomarkers and exoenzyme kinetics through the four years except that the acid phosphatase activities declined after 3 years applications. P applications enhanced the soil N cycling by increases the abundances of nitrifiers (ammonia-oxidizing archea) and denitrifiers (nos Z, norG, and nirK). The bacterial and fungal residue carbons (calculated by amino sugar indicators) were higher under NP fertilizations than the other treatments. Our results suggest that P application could improve the soil

  18. [Effects of biochar addition into soils in semiarid land on water infiltration under the condition of the same bulk density].

    PubMed

    Qi, Rui-Peng; Zhang, Lei; Yan, Yong-Hao; Wen, Man; Zheng, Ji-Yong

    2014-08-01

    Making clear the effects of biochar addition on soil water infiltration process can provide the scientific basis for the evaluation of the influence of biochar application on soil hydrology in semi-arid region. In this paper, through the soil column simulation method in laboratory, the effects of biochar of three sizes (1-2 mm, 0.25-1 mm and ≤ 0.25 mm) at 4 doses (10, 50, 100 and 150 g x kg(-1)) on the cumulative infiltration, the permeability and the stable infiltration rate of two different soils (anthrosol and aeolian sandy soil) were studied. The results showed that the infiltration capacity of the anthrosol was obviously increased compared to the control, however, the one in the aeolian sandy soil was decreased due to the biochar addition. At 100 minutes after infiltration starting, the averaged cumulative infiltration was increased by 25.1% in the anthrosol with comparison to the control. Contrarily, the averaged cumulative infiltration was decreased by 11.1% in the aeolian sandy soil at 15 minutes after infiltration starting. When the dose was the same, biochar with different particle sizes improved the infiltration for the anthrosol, but for the different dose treatments, the particle size of biochar which showed the greatest improvement was different. As for the aeolian sandy soil, the infiltration increased at the dose of 10 g x kg(-1) after the addition of biochar with different particle sizes, while decreased at the higher dose of 50, 100 and 150 g x kg(-1). The cumulative infiltration of the aeolian sandy soil was decreased with the increase in addition amount of biochar with the same particle size, while it was not so for the anthrosol. The determination coefficient fitted by the Philip infiltration model ranged from 0.965 to 0.999, suggesting this model was suitable for the simulation of soil water infiltration process after biochar application. Statistical analysis of main effects showed that the biochar particle size, the biochar addition amount

  19. 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.

  20. Application of a Permethrin Immunosorbent Assay Method to Residential Soil and Dust Samples

    EPA Science Inventory

    A low-cost, high throughput bioanalytical screening method was developed for monitoring cis/trans-permethrin in dust and soil samples. The method consisted of a simple sample preparation procedure [sonication with dichloromethane followed by a solvent exchange into methanol:wate...

  1. Balloon and core sampling for determining bulk density of alluvial desert soil

    USGS Publications Warehouse

    Andraski, B.J.

    1991-01-01

    Samples were collected from major strata in the upper 5 m of an alluvial soil profile in the Amargosa Desert of southern Nevada to compare rubber-balloon and drive-core bulk-density measurement methods. Outside the range of fine-soil texture, where soil consistency was either very loose or very hard, the core method appeared to sample inaccurately, resulting in bulk-density values less than those determined by the balloon method. Under the severe sampling conditions encountered, large decreases in the relative accuracy of the core method were not directly related to rock-fragment content, but were related to extremes in the cohesiveness of the strata sampled. -from Author

  2. Differential responses of short-term soil respiration dynamics to the experimental addition of nitrogen and water in the temperate semi-arid steppe of Inner Mongolia, China.

    PubMed

    Qi, Yuchun; Liu, Xinchao; Dong, Yunshe; Peng, Qin; He, Yating; Sun, Liangjie; Jia, Junqiang; Cao, Congcong

    2014-04-01

    We examined the effects of simulated rainfall and increasing N supply of different levels on CO2 pulse emission from typical Inner Mongolian steppe soil using the static opaque chamber technique, respectively in a dry June and a rainy August. The treatments included NH4NO3 additions at rates of 0, 5, 10, and 20 g N/(m(2)·year) with or without water. Immediately after the experimental simulated rainfall events, the CO2 effluxes in the watering plots without N addition (WCK) increased greatly and reached the maximum value at 2 hr. However, the efflux level reverted to the background level within 48 hr. The cumulative CO2 effluxes in the soil rang ed from 5.60 to 6.49 g C/m(2) over 48 hr after a single water application, thus showing an increase of approximately 148.64% and 48.36% in the effluxes during both observation periods. By contrast, the addition of different N levels without water addition did not result in a significant change in soil respiration in the short term. Two-way ANOVA showed that the effects of the interaction between water and N addition were insignificant in short-term soil CO2 effluxes in the soil. The cumulative soil CO2 fluxes of different treatments over 48 hr accounted for approximately 5.34% to 6.91% and 2.36% to 2.93% of annual C emission in both experimental periods. These results stress the need for improving the sampling frequency after rainfall in future studies to ensure more accurate evaluation of the grassland C emission contribution. PMID:25079414

  3. Differential responses of short-term soil respiration dynamics to the experimental addition of nitrogen and water in the temperate semi-arid steppe of Inner Mongolia, China.

    PubMed

    Qi, Yuchun; Liu, Xinchao; Dong, Yunshe; Peng, Qin; He, Yating; Sun, Liangjie; Jia, Junqiang; Cao, Congcong

    2014-04-01

    We examined the effects of simulated rainfall and increasing N supply of different levels on CO2 pulse emission from typical Inner Mongolian steppe soil using the static opaque chamber technique, respectively in a dry June and a rainy August. The treatments included NH4NO3 additions at rates of 0, 5, 10, and 20 g N/(m(2)·year) with or without water. Immediately after the experimental simulated rainfall events, the CO2 effluxes in the watering plots without N addition (WCK) increased greatly and reached the maximum value at 2 hr. However, the efflux level reverted to the background level within 48 hr. The cumulative CO2 effluxes in the soil rang ed from 5.60 to 6.49 g C/m(2) over 48 hr after a single water application, thus showing an increase of approximately 148.64% and 48.36% in the effluxes during both observation periods. By contrast, the addition of different N levels without water addition did not result in a significant change in soil respiration in the short term. Two-way ANOVA showed that the effects of the interaction between water and N addition were insignificant in short-term soil CO2 effluxes in the soil. The cumulative soil CO2 fluxes of different treatments over 48 hr accounted for approximately 5.34% to 6.91% and 2.36% to 2.93% of annual C emission in both experimental periods. These results stress the need for improving the sampling frequency after rainfall in future studies to ensure more accurate evaluation of the grassland C emission contribution.

  4. Situ soil sampling probe system with heated transfer line

    DOEpatents

    Robbat, Jr., Albert

    2002-01-01

    The present invention is directed both to an improved in situ penetrometer probe and to a heated, flexible transfer line. The line and probe may be implemented together in a penetrometer system in which the transfer line is used to connect the probe to a collector/analyzer at the surface. The probe comprises a heater that controls a temperature of a geologic medium surrounding the probe. At least one carrier gas port and vapor collection port are located on an external side wall of the probe. The carrier gas port provides a carrier gas into the geologic medium, and the collection port captures vapors from the geologic medium for analysis. In the transfer line, a flexible collection line that conveys a collected fluid, i.e., vapor, sample to a collector/analyzer. A flexible carrier gas line conveys a carrier gas to facilitate the collection of the sample. A system heating the collection line is also provided. Preferably the collection line is electrically conductive so that an electrical power source can generate a current through it so that the internal resistance generates heat.

  5. RESULTS FROM EPA FUNDED RESEARCH PROGRAMS ON THE IMPORTANCE OF PURGE VOLUME, SAMPLE VOLUME, SAMPLE FLOW RATE AND TEMPORAL VARIATIONS ON SOIL GAS CONCENTRATIONS

    EPA Science Inventory

    Two research studies funded and overseen by EPA have been conducted since October 2006 on soil gas sampling methods and variations in shallow soil gas concentrations with the purpose of improving our understanding of soil gas methods and data for vapor intrusion applications. Al...

  6. Representing major soil variability at regional scale by constrained Latin Hypercube Sampling of remote sensing data

    NASA Astrophysics Data System (ADS)

    Mulder, V. L.; de Bruin, S.; Schaepman, M. E.

    2013-04-01

    This paper presents a sparse, remote sensing-based sampling approach making use of conditioned Latin Hypercube Sampling (cLHS) to assess variability in soil properties at regional scale. The method optimizes the sampling scheme for a defined spatial population based on selected covariates, which are assumed to represent the variability of the target variables. The optimization also accounts for specific constraints and costs expressing the field sampling effort. The approach is demonstrated using a case study in Morocco, where a small but representative sample record had to be collected over a 15,000 km2 area within 2 weeks. The covariate space of the Latin Hypercube consisted of the first three principal components of ASTER imagery as well as elevation. Comparison of soil properties taken from the topsoil with the existing soil map, a geological map and lithological data showed that the sampling approach was successful in representing major soil variability. The cLHS sample failed to express spatial correlation; constraining the LHS by a distance criterion favoured large spatial variability within a short distances resulting in an overestimation of the variograms nugget and short distance variability. However, the exhaustive covariate data appeared to be spatially correlated which supports our premise that once the relation between spatially explicit remote sensing data and soil properties has been modelled, the latter can be spatially predicted based on the densely sampled remotely sensed data. Therefore, the LHS approach is considered as time and cost efficient for regional scale surveys that rely on remote sensing-based prediction of soil properties.

  7. Accurately measuring volume of soil samples using low cost Kinect 3D scanner

    NASA Astrophysics Data System (ADS)

    van der Sterre, Boy-Santhos; Hut, Rolf; van de Giesen, Nick

    2013-04-01

    The 3D scanner of the Kinect game controller can be used to increase the accuracy and efficiency of determining in situ soil moisture content. Soil moisture is one of the principal hydrological variables in both the water and energy interactions between soil and atmosphere. Current in situ measurements of soil moisture either rely on indirect measurements (of electromagnetic constants or heat capacity) or on physically taking a sample and weighing it in a lab. The bottleneck in accurately retrieving soil moisture using samples is the determining of the volume of the sample. Currently this is mostly done by the very time consuming "sand cone method" in which the volume were the sample used to sit is filled with sand. We show that 3D scanner that is part of the 150 game controller extension "Kinect" can be used to make 3D scans before and after taking the sample. The accuracy of this method is tested by scanning forms of known volume. This method is less time consuming and less error-prone than using a sand cone.

  8. Accurately measuring volume of soil samples using low cost Kinect 3D scanner

    NASA Astrophysics Data System (ADS)

    van der Sterre, B.; Hut, R.; Van De Giesen, N.

    2012-12-01

    The 3D scanner of the Kinect game controller can be used to increase the accuracy and efficiency of determining in situ soil moisture content. Soil moisture is one of the principal hydrological variables in both the water and energy interactions between soil and atmosphere. Current in situ measurements of soil moisture either rely on indirect measurements (of electromagnetic constants or heat capacity) or on physically taking a sample and weighing it in a lab. The bottleneck in accurately retrieving soil moisture using samples is the determining of the volume of the sample. Currently this is mostly done by the very time consuming "sand cone method" in which the volume were the sample used to sit is filled with sand. We show that 3D scanner that is part of the $150 game controller extension "Kinect" can be used to make 3D scans before and after taking the sample. The accuracy of this method is tested by scanning forms of known volume. This method is less time consuming and less error-prone than using a sand cone.

  9. Local versus field scale soil heterogeneity characterization - a challenge for representative sampling in pollution studies

    NASA Astrophysics Data System (ADS)

    Kardanpour, Z.; Jacobsen, O. S.; Esbensen, K. H.

    2015-06-01

    This study is a contribution to development of a heterogeneity characterisation facility for "next generation" sampling aimed at more realistic and controllable pesticide variability in laboratory pots in experimental environmental contaminant assessment. The role of soil heterogeneity on quantification of a set of exemplar parameters, organic matter, loss on ignition (LOI), biomass, soil microbiology, MCPA sorption and mineralization is described, including a brief background on how heterogeneity affects sampling/monitoring procedures in environmental pollutant studies. The Theory of Sampling (TOS) and variographic analysis has been applied to develop a fit-for-purpose heterogeneity characterization approach. All parameters were assessed in large-scale profile (1-100 m) vs. small-scale (0.1-1 m) replication sampling pattern. Variographic profiles of experimental analytical results concludes that it is essential to sample at locations with less than a 2.5 m distance interval to benefit from spatial auto-correlation and thereby avoid unnecessary, inflated compositional variation in experimental pots; this range is an inherent characteristic of the soil heterogeneity and will differ among soils types. This study has a significant carrying-over potential for related research areas e.g. soil science, contamination studies, and environmental monitoring and environmental chemistry.

  10. PIXE Analysis of Aerosol and Soil Samples Collected in the Adirondack Mountains

    NASA Astrophysics Data System (ADS)

    Yoskowitz, Joshua; Ali, Salina; Nadareski, Benjamin; Labrake, Scott; Vineyard, Michael

    2014-09-01

    We have performed an elemental analysis of aerosol and soil samples collected at Piseco Lake in Upstate New York using proton induced X-ray emission spectroscopy (PIXE). This work is part of a systematic study of airborne pollution in the Adirondack Mountains. Of particular interest is the sulfur content that can contribute to acid rain, a well-documented problem in the Adirondacks. We used a nine-stage cascade impactor to collect the aerosol samples near Piseco Lake and distribute the particulate matter onto Kapton foils by particle size. The soil samples were also collected at Piseco Lake and pressed into cylindrical pellets for experimentation. PIXE analysis of the aerosol and soil samples were performed with 2.2-MeV proton beams from the 1.1-MV Pelletron accelerator in the Union College Ion-Beam Analysis Laboratory. There are higher concentrations of sulfur at smaller particle sizes (0.25-1 μm), suggesting that it could be suspended in the air for days and originate from sources very far away. Other elements with significant concentrations peak at larger particle sizes (1-4 μm) and are found in the soil samples, suggesting that these elements could originate in the soil. The PIXE analysis will be described and the resulting data will be presented.

  11. CTEPP STANDARD OPERATING PROCEDURE FOR COLLECTION OF SOIL SAMPLES FOR PERSISTENT ORGANIC POLLUTANTS (SOP-2.20)

    EPA Science Inventory

    This SOP describes the method for collecting soil samples from the child's outdoor play area to measure for persistent organic pollutants. Soil samples are collected by scraping up the top 0.5 cm of soil in a 0.095 m2 (1 ft2) area in the middle of the child's play area.

  12. Isolation and partial characterization of phosphate solubilizing bacteria isolated from soil and marine samples.

    PubMed

    Mujahid, Talat Yasmeen; Siddiqui, Khaizran; Ahmed, Rifat; Kazmi, Shahana U; Ahmed, Nuzhat

    2014-09-01

    In the present study the potential of indigenous bacterial isolates from soil rhizosphere and marine environment to promote plant growth was determined. Eight bacterial strains isolated from soil and marine samples were characterized for the phosphate solubilizing activity. Qualitative and quantitative estimation of phosphate solubilization is done. MIC of antibiotic and heavy metals were checked for these strains. Strains show a diverse pattern of antibiotic and heavy metals resistance.

  13. Integrated Field Lysimetry and Porewater Sampling for Evaluation of Chemical Mobility in Soils and Established Vegetation

    PubMed Central

    Gannon, Travis W.; Polizzotto, Matthew L.

    2014-01-01

    Potentially toxic chemicals are routinely applied to land to meet growing demands on waste management and food production, but the fate of these chemicals is often not well understood. Here we demonstrate an integrated field lysimetry and porewater sampling method for evaluating the mobility of chemicals applied to soils and established vegetation. Lysimeters, open columns made of metal or plastic, are driven into bareground or vegetated soils. Porewater samplers, which are commercially available and use vacuum to collect percolating soil water, are installed at predetermined depths within the lysimeters. At prearranged times following chemical application to experimental plots, porewater is collected, and lysimeters, containing soil and vegetation, are exhumed. By analyzing chemical concentrations in the lysimeter soil, vegetation, and porewater, downward leaching rates, soil retention capacities, and plant uptake for the chemical of interest may be quantified. Because field lysimetry and porewater sampling are conducted under natural environmental conditions and with minimal soil disturbance, derived results project real-case scenarios and provide valuable information for chemical management. As chemicals are increasingly applied to land worldwide, the described techniques may be utilized to determine whether applied chemicals pose adverse effects to human health or the environment. PMID:25045915

  14. Optimal spatial sampling techniques for ground truth data in microwave remote sensing of soil moisture

    NASA Technical Reports Server (NTRS)

    Rao, R. G. S.; Ulaby, F. T.

    1977-01-01

    The paper examines optimal sampling techniques for obtaining accurate spatial averages of soil moisture, at various depths and for cell sizes in the range 2.5-40 acres, with a minimum number of samples. Both simple random sampling and stratified sampling procedures are used to reach a set of recommended sample sizes for each depth and for each cell size. Major conclusions from statistical sampling test results are that (1) the number of samples required decreases with increasing depth; (2) when the total number of samples cannot be prespecified or the moisture in only one single layer is of interest, then a simple random sample procedure should be used which is based on the observed mean and SD for data from a single field; (3) when the total number of samples can be prespecified and the objective is to measure the soil moisture profile with depth, then stratified random sampling based on optimal allocation should be used; and (4) decreasing the sensor resolution cell size leads to fairly large decreases in samples sizes with stratified sampling procedures, whereas only a moderate decrease is obtained in simple random sampling procedures.

  15. Sampling design optimization for multivariate soil mapping, case study from Hungary

    NASA Astrophysics Data System (ADS)

    Szatmári, Gábor; Pásztor, László; Barta, Károly

    2014-05-01

    Direct observations of the soil are important for two main reasons in Digital Soil Mapping (DSM). First, they are used to characterize the relationship between the soil property of interest and the auxiliary information. Second, they are used to improve the predictions based on the auxiliary information. Hence there is a strong necessity to elaborate a well-established soil sampling strategy based on geostatistical tools, prior knowledge and available resources before the samples are actually collected from the area of interest. Fieldwork and laboratory analyses are the most expensive and labor-intensive part of DSM, meanwhile the collected samples and the measured data have a remarkable influence on the spatial predictions and their uncertainty. Numerous sampling strategy optimization techniques developed in the past decades. One of these optimization techniques is Spatial Simulated Annealing (SSA) that has been frequently used in soil surveys to minimize the average universal kriging variance. The benefit of the technique is, that the surveyor can optimize the sampling design for fixed number of observations taking auxiliary information, previously collected samples and inaccessible areas into account. The requirements are the known form of the regression model and the spatial structure of the residuals of the model. Another restriction is, that the technique is able to optimize the sampling design for just one target soil variable. However, in practice a soil survey usually aims to describe the spatial distribution of not just one but several pedological variables. In the recent paper we present a procedure developed in R-code to simultaneously optimize the sampling design by SSA for two soil variables using spatially averaged universal kriging variance as optimization criterion. Soil Organic Matter (SOM) content and rooting depth were chosen for this purpose. The methodology is illustrated with a legacy data set from a study area in Central Hungary. Legacy soil

  16. Toward a mechanistic understanding of the effect of biochar addition on soil water retention

    NASA Astrophysics Data System (ADS)

    Yi, S.; Chang, N.; Guo, M.; Imhoff, P. T.

    2014-12-01

    Biochar (BC) is a carbon-rich product produced by thermal degradation of biomass in an oxygen-free environment, whose application to sediment is said to improve water retention. However, BC produced from different feedstocks and pyrolyzed at different temperatures have distinct properties, which may alter water retention in ways difficult to predict a priori. Our goal is to develop a mechanistic understanding of BC addition on water retention by examining the impact of BC from two feedstocks, poultry litter (PL) and hardwood (HW), on the soil-water retention curves (SWRC) of a uniform sand and a sandy loam (SL). For experiments with sand, BC and sand were sieved to the same particle size (~ 0.547 mm) to minimize effects of BC addition on particle size distribution. Experiments with SL contained the same sieved BC. PL and HW bicohars were added at 2 and 7% (w/w), and water retention was measured from 0 to -4.38 × 106 cm-H2O. Both BCs increased porosities for sand and SL, up to 39 and 13% for sand and SL, respectively, with 7% HW BC addition. The primary cause for these increases was the internal porosity of BC particles. While the matric potential for air-entry was unchanged with BC addition, BC amendment increased water retention for sand and SL in the capillary region (0 to -15,000 cm-H2O) by an average of 26 and 33 % for 7% PL and HW BC in sand, respectively, but only 7 and 14 % for 7% PL and HW BC in SL. The most dramatic influence of BC amendment on water retention occurred in the adsorption region (< -15,000 cm-H2O), where water retention increased by a factor of 11 and 22 for 7% PL and HW BC in sand, respectively, but by 140 and 190 % for 7% PL and HW BC in SL, respectively. The impact of BC on water retention in these sediments is explained primarily by the additional surface area and internal porosity of PL and HW BC particles. van Genuchten (VG) models were fitted to the water retention data. For SL where the impact of BC addition on water retention was

  17. Sulphate reducing activity detected in soil samples from Antarctica, Ecology Glacier Forefield, King George Island.

    PubMed

    Wolicka, Dorota; Zdanowski, Marek K; Żmuda-Baranowska, Magdalena J; Poszytek, Anna; Grzesiak, Jakub

    2014-01-01

    We determined sulphate-reducing activities in media inoculated with soils and with kettle lake sediments in order to investigate their potential in geomicrobiological processes in low-temperature, terrestrial maritime Antarctic habitats. Soil and sediment samples were collected in a glacier valley abandoned by Ecology Glacier during the last 30 years: from a new formed kettle lake sediment and forefield soil derived from ground moraine. Inoculated with these samples, liquid Postgate C and minimal media supplemented with various carbon sources as electron donors were incubated for 8 weeks at 4°C. High rates of sulphate reduction were observed only in media inoculated with soil. No sulphate reduction was detected in media inoculated with kettle lake sediments. In soil samples culture media calcite and elemental sulphur deposits were observed, demonstrating that sulphate-reducing activity is associated with a potential to mineral formation in cold environments. Cells observed on scanning microscopy (SEM) micrographs of post-culture-soil deposits could be responsible for sulphate-reducing activity. PMID:25804064

  18. Sulphate reducing activity detected in soil samples from Antarctica, Ecology Glacier Forefield, King George Island.

    PubMed

    Wolicka, Dorota; Zdanowski, Marek K; Żmuda-Baranowska, Magdalena J; Poszytek, Anna; Grzesiak, Jakub

    2014-01-01

    We determined sulphate-reducing activities in media inoculated with soils and with kettle lake sediments in order to investigate their potential in geomicrobiological processes in low-temperature, terrestrial maritime Antarctic habitats. Soil and sediment samples were collected in a glacier valley abandoned by Ecology Glacier during the last 30 years: from a new formed kettle lake sediment and forefield soil derived from ground moraine. Inoculated with these samples, liquid Postgate C and minimal media supplemented with various carbon sources as electron donors were incubated for 8 weeks at 4°C. High rates of sulphate reduction were observed only in media inoculated with soil. No sulphate reduction was detected in media inoculated with kettle lake sediments. In soil samples culture media calcite and elemental sulphur deposits were observed, demonstrating that sulphate-reducing activity is associated with a potential to mineral formation in cold environments. Cells observed on scanning microscopy (SEM) micrographs of post-culture-soil deposits could be responsible for sulphate-reducing activity.

  19. Restoration of species-rich grasslands on ex-arable land: seed addition outweighs soil fertility reduction

    SciTech Connect

    Kardol, Paul

    2008-01-01

    A common practice in biodiversity conservation is restoration of former species-rich grassland on ex-arable land. Major constraints for grassland restoration are high soil fertility and limited dispersal ability of plant species to target sites. Usually, studies focus on soil fertility or on methods to introduce plant seeds. However, the question is whether soil fertility reduction is always necessary for getting plant species established on target sites. In a three-year field experiment with ex-arable soil with intensive farming history, we tested single and combined effects of soil fertility reduction and sowing mid-successional plant species on plant community development and soil biological properties. A controlled microcosm study was performed to test short-term effects of soil fertility reduction measures on biomass production of mid-successional species. Soil fertility was manipulated by adding carbon (wood or straw) to incorporate plant-available nutrients into organic matter, or by removing nutrients through top soil removal (TSR). The sown species established successfully and their establishment was independent of carbon amendments. TSR reduced plant biomass, and effectively suppressed arable weeds, however, created a desert-like environment, inhibiting the effectiveness of sowing mid-successional plant species. Adding straw or wood resulted in short-term reduction of plant biomass, suggesting a temporal decrease in plant-available nutrients by microbial immobilisation. Straw and wood addition had little effects on soil biological properties, whereas TSR profoundly reduced numbers of bacteria, fungal biomass and nematode abundance. In conclusion, in ex-arable soils, on a short term sowing is more effective for grassland restoration than strategies aiming at soil fertility reduction.

  20. Radon exhalation from Libyan soil samples measured with the SSNTD technique.

    PubMed

    Saad, A F; Abdallah, R M; Hussein, N A

    2013-02-01

    Radon concentrations in soil samples collected from the cities of Benghazi and Al-Marj, located in northeastern Libya, were measured using the sealed-can technique based on the CR-39 SSNTDs. Mass and areal radon exhalation rates, radium content and radon concentration contribute to indoor radon, and annual effective doses were determined. The results indicate mostly normal rates, but there were some higher levels of radon concentration and emanation in samples collected from Al-Marj and one sample from Benghazi.

  1. Analysis of core soil and water samples from the Cactus Crater Disposal Site at Enewetak atoll

    SciTech Connect

    Robison, W.L.; Noshkin, V.E.

    1981-02-18

    Core soil samples and water samples were collected from the Cactus Crater Disposal Site at Enewetak for analysis of /sup 137/Cs, /sup 90/Sr, /sup 239 +240/Pu and /sup 241/Am by both gamma spectroscopy and, through a contractor laboratory, by wet chemistry procedures. The samples processing methods, the analytical methods and the analytical quality control are all procedures developed for the continuing Marshall Island radioecology and dose assessment work.

  2. A novel in situ method for sampling urban soil dust: particle size distribution, trace metal concentrations, and stable lead isotopes.

    PubMed

    Bi, Xiangyang; Liang, Siyuan; Li, Xiangdong

    2013-06-01

    In this study, a novel in situ sampling method was utilized to investigate the concentrations of trace metals and Pb isotope compositions among different particle size fractions in soil dust, bulk surface soil, and corresponding road dust samples collected within an urban environment. The aim of the current study was to evaluate the feasibility of using soil dust samples to determine trace metal contamination and potential risks in urban areas in comparison with related bulk surface soil and road dust. The results of total metal loadings and Pb isotope ratios revealed that soil dust is more sensitive than bulk surface soil to anthropogenic contamination in urban areas. The new in situ method is effective at collecting different particle size fractions of soil dust from the surface of urban soils, and that soil dust is a critical indicator of anthropogenic contamination and potential human exposure in urban settings.

  3. A Monte Carlo approach to estimate the uncertainty in soil CO2 emissions caused by spatial and sample size variability.

    PubMed

    Shi, Wei-Yu; Su, Li-Jun; Song, Yi; Ma, Ming-Guo; Du, Sheng

    2015-10-01

    The soil CO2 emission is recognized as one of the largest fluxes in the global carbon cycle. Small errors in its estimation can result in large uncertainties and have important consequences for climate model predictions. Monte Carlo approach is efficient for estimating and reducing spatial scale sampling errors. However, that has not been used in soil CO2 emission studies. Here, soil respiration data from 51 PVC collars were measured within farmland cultivated by maize covering 25 km(2) during the growing season. Based on Monte Carlo approach, optimal sample sizes of soil temperature, soil moisture, and soil CO2 emission were determined. And models of soil respiration can be effectively assessed: Soil temperature model is the most effective model to increasing accuracy among three models. The study demonstrated that Monte Carlo approach may improve soil respiration accuracy with limited sample size. That will be valuable for reducing uncertainties of global carbon cycle.

  4. A Monte Carlo approach to estimate the uncertainty in soil CO2 emissions caused by spatial and sample size variability.

    PubMed

    Shi, Wei-Yu; Su, Li-Jun; Song, Yi; Ma, Ming-Guo; Du, Sheng

    2015-10-01

    The soil CO2 emission is recognized as one of the largest fluxes in the global carbon cycle. Small errors in its estimation can result in large uncertainties and have important consequences for climate model predictions. Monte Carlo approach is efficient for estimating and reducing spatial scale sampling errors. However, that has not been used in soil CO2 emission studies. Here, soil respiration data from 51 PVC collars were measured within farmland cultivated by maize covering 25 km(2) during the growing season. Based on Monte Carlo approach, optimal sample sizes of soil temperature, soil moisture, and soil CO2 emission were determined. And models of soil respiration can be effectively assessed: Soil temperature model is the most effective model to increasing accuracy among three models. The study demonstrated that Monte Carlo approach may improve soil respiration accuracy with limited sample size. That will be valuable for reducing uncertainties of global carbon cycle. PMID:26664693

  5. The EXOMARS High Resolution Camera (HRC) for Mars Landscape Observation and Soil Samples Inspection

    NASA Astrophysics Data System (ADS)

    Mosebach, Herbert; Gutruf, Sven; Glier, Markus; Michaelis, Harald; Schmitz, Nicole

    In co-operation with the DLR, Kayser-Threde is developing the High Resolution Camera (HRC) as one of the core scientific instruments on the EXOMARS rover. The HRC is part of the Panoramic Camera (PanCam) system, and the one with a high optical resolution. The main objectives of the camera are to observe interesting land sites on MARS, to assist the rover during locomotion. Additionally, the collected soil samples put by the drill into the sample tray of the rover shall be inspected before feeding the tray into the inside of the rover for scientific investigation. The camera is integrated inside the overall PanCam housing, which is located atop the rover mast as a cross bar. The instrument consists of a focus mechanism to adjust the focus range between 1 m and infinity. The FOV of the camera is 4.5 degrees, which leads to a resolution of about 0.8 mm at 10 m object distance. The camera is equipped with a 1024x1024 pixel detector, on which a RGB filter is applied. In this configuration colour images with the HRC are possible. placeMission launch is scheduled for early 2018. The landing on Mars is expected for the following year. This paper presents the objectives of the HRC camera, its optical and opto-mechanical design as well as the current development status.

  6. Artificial Warming and Rain Addition Increase Phenol Oxidase Activity in Arctic Soils

    NASA Astrophysics Data System (ADS)

    Kang, H.; Seo, J.; Jang, I.; Lee, Y. K.

    2014-12-01

    Artic tundra is one of the largest carbon stocks, of which amount is estimated up to 1,600 Pg. Global climate change models predict surface temperature rise and higher precipitation during summer in Arctic regions, raising concerns about faster decomposition of organic carbon and consequent releases of CO2, CH4 and DOC. Microorganisms are directly involved in decomposition process by releasing various extracellular enzymes. In particular, phenol oxidase was noted to play a key role because it is related to dynamics of highly recalcitrant carbon, which often represents a rate-limiting step of overall decomposition. In this study, we monitored phenol oxidase activity, hydrolases (β-glucosidase, cellobiohydrolase, N-acetylglucosaminidase and aminopeptidase), microbial abundance (qPCR) and chemical properties (δ13C and δ15N signatures) of tundra soils exposed to artificial warming and rain addition, by employing a passive chamber method in Cambridge Bay, Canada. Warming and rain addition combinedly increased phenol oxidase activity while no such changes were discernible for other hydrolases. Stable isotope signature indicates that warming induced water stress to the ecosystem and that nitrogen availability may be enhanced, which is partially responsible for the changes in enzyme activities. A short-term warming (2 years) may not accelerate mineralization of easily decomposable carbon, but may affect phenol oxidase which has the longer-term influence on recalcitrant carbon.

  7. Uncertainty assessment of heavy metal soil contamination mapping using spatiotemporal sequential indicator simulation with multi-temporal sampling points.

    PubMed

    Yang, Yong; Christakos, George

    2015-09-01

    Mapping the space-time distribution of heavy metals in soils plays a key role in contaminated site classification under conditions of in situ uncertainty, whereas uncertainty assessment is based on the quantification of the specific uncertainties in terms of exceedance probabilities. Geostatistical space-time kriging (STK) is increasingly used to estimate pollutant concentrations in soils. Sequential indicator simulation (SIS) technique is popular in uncertainty assessment of heavy metal contamination of soils. However, these techniques cannot handle multi-temporal data. In this work, spatiotemporal sequential indicator simulation (STSIS) based on an additive space-time semivariogram model (STSIS_A) and on a non-separable space-time semivariogram model (STSIS_NS) was used to assimilate multi-temporal data in the mapping and uncertainty assessment of heavy metal distributions in contaminated soils. Cu concentrations in soils sampled during the period 2010-2014 in the Qingshan district (Wuhan City, Hubei Province, China) were used as the experimental data set. Based on a number of STSIS realizations, we assessed different kinds of mapping uncertainty, including single-location uncertainty during 1 year and during multiple years, multi-location uncertainty during 1 year, and during multiple years. The comparison of the STSIS technique vs. SIS and STK techniques showed that STSIS performs better than both STK and SIS.

  8. Successful implementation of biochar carbon sequestration in European soils requires additional benefits and close collaboration with the bioenergy sector

    NASA Astrophysics Data System (ADS)

    Hauggaard-Nielsen, Henrik; Müller-Stöver, Dorette; Bruun, Esben W.; Petersen, Carsten T.

    2014-05-01

    Biochar soil application has been proposed as a measure to mitigate climate change and on the same time improve soil fertility by increased soil carbon sequestration. However, while on tropical soils the beneficial effects of biochar application on crop growth often become immediately apparent, it has been shown to be more difficult to demonstrate these effects on the more fertile soils in temperate regions. Therefore and because of the lack of carbon credits for farmers, it is necessary to link biochar application to additional benefits, both related to agricultural as well as to bioenergy production. Thermal gasification of biomass is an efficient (95% energy efficiency) and flexible way (able to cope with many different and otherwise difficult-to-handle biomass fuels) to generate bioenergy, while producing a valuable by-product - gasification biochar, containing recalcitrant carbon and essential crop nutrients. The use of the residual char product in agricultural soils will add value to the technology as well as result in additional soil benefits such as providing plant nutrients and improving soil water-holding capacity while reducing leaching risks. From a soil column (30 x 130 cm) experiment with gasification straw biochar amendment to coarse sandy subsoil increased root density of barley at critical depths in the soil profile reducing the mechanical resistance was shown, increasing yields, and the soil's capacity to store plant available water. Incorporation of residuals from a bioenergy technology like gasification show great potentials to reduce subsoil constraints increasing yield potentials on poor soils. Another advantage currently not appropriately utilized is recovery of phosphorus (P). In a recent pot experiments char products originating from low-temperature gasification of various biofuels were evaluated for their suitability as P fertilizers. Wheat straw gasification biochar generally had a low P content but a high P plant availability. To improve

  9. Application of portable gas chromatography-photo ionization detector combined with headspace sampling for field analysis of benzene, toluene, ethylbenzene, and xylene in soils.

    PubMed

    Zhou, You-Ya; Yu, Ji-Fang; Yan, Zeng-Guang; Zhang, Chao-Yan; Xie, Ya-Bo; Ma, Li-Qiang; Gu, Qing-Bao; Li, Fa-Sheng

    2013-04-01

    A method based on headspace (HS) sampling coupling with portable gas chromatography (GC) with photo ionization detector (PID) was developed for rapid determination of benzene, toluene, ethylbenzene, and xylenes (BTEX) in soils. Optimal conditions for HS gas sampling procedure were determined, and the influence of soil organic matter on the recovery of BTEX from soil was investigated using five representative Chinese soils. The results showed that the HS-portable-GC-PID method could be effectively operated at ambient temperature, and the addition of 15 ml of saturated NaCl solution in a 40-ml sampling vial and 60 s of shaking time for sample solution were optimum for the HS gas sampling procedure. The recoveries of each BTEX in soils ranged from 87.2 to 105.1 %, with relative standard deviations varying from 5.3 to 7.8 %. Good linearity was obtained for all BTEX compounds, and the detection limits were in the 0.1 to 0.8 μg kg(-1) range. Soil organic matter was identified as one of the principal elements that affect the HS gas sampling of BTEX in soils. The HS-portable-GC-PID method was successfully applied for field determination of benzene and toluene in soils of a former chemical plant in Jilin City, northeast China. Considering its satisfactory repeatability and reproducibility and particular suitability to be operated in ambient environment, HS sampling coupling with portable GC-PID is, therefore, recommended to be a suitable screening tool for rapid on-site determination of BTEX in soils.

  10. Assessment of sampling and analytical uncertainty of trace element contents in arable field soils.

    PubMed

    Buczko, Uwe; Kuchenbuch, Rolf O; Ubelhör, Walter; Nätscher, Ludwig

    2012-07-01

    Assessment of trace element contents in soils is required in Germany (and other countries) before sewage sludge application on arable soils. The reliability of measured element contents is affected by measurement uncertainty, which consists of components due to (1) sampling, (2) laboratory repeatability (intra-lab) and (3) reproducibility (between-lab). A complete characterization of average trace element contents in field soils should encompass the uncertainty of all these components. The objectives of this study were to elucidate the magnitude and relative proportions of uncertainty components for the metals As, B, Cd, Co, Cr, Mo, Ni, Pb, Tl and Zn in three arable fields of different field-scale heterogeneity, based on a collaborative trial (CT) (standardized procedure) and two sampling proficiency tests (PT) (individual sampling procedure). To obtain reference values and estimates of field-scale heterogeneity, a detailed reference sampling was conducted. Components of uncertainty (sampling person, sampling repetition, laboratory) were estimated by variance component analysis, whereas reproducibility uncertainty was estimated using results from numerous laboratory proficiency tests. Sampling uncertainty in general increased with field-scale heterogeneity; however, total uncertainty was mostly dominated by (total) laboratory uncertainty. Reproducibility analytical uncertainty was on average by a factor of about 3 higher than repeatability uncertainty. Therefore, analysis within one single laboratory and, for heterogeneous fields, a reduction of sampling uncertainty (for instance by larger numbers of sample increments and/or a denser coverage of the field area) would be most effective to reduce total uncertainty. On the other hand, when only intra-laboratory analytical uncertainty was considered, total sampling uncertainty on average prevailed over analytical uncertainty by a factor of 2. Both sampling and laboratory repeatability uncertainty were highly variable

  11. Effects of Fertilization and Sampling Time on Composition and Diversity of Entire and Active Bacterial Communities in German Grassland Soils

    PubMed Central

    Herzog, Sarah; Wemheuer, Franziska; Wemheuer, Bernd; Daniel, Rolf

    2015-01-01

    Soil bacteria are major players in driving and regulating ecosystem processes. Thus, the identification of factors shaping the diversity and structure of these communities is crucial for understanding bacterial-mediated processes such as nutrient transformation and cycling. As most studies only target the entire soil bacterial community, the response of active community members to environmental changes is still poorly understood. The objective of this study was to investigate the effect of fertilizer application and sampling time on structure and diversity of potentially active (RNA-based) and the entire (DNA-based) bacterial communities in German grassland soils. Analysis of more than 2.3 million 16S rRNA transcripts and gene sequences derived from amplicon-based sequencing of 16S rRNA genes revealed that fertilizer application and sampling time significantly altered the diversity and composition of entire and active bacterial communities. Although the composition of both the entire and the active bacterial community was correlated with environmental factors such as pH or C/N ratio, the active community showed a higher sensitivity to environmental changes than the entire community. In addition, functional analyses were performed based on predictions derived from 16S rRNA data. Genes encoding the uptake of nitrate/nitrite, nitrification, and denitrification were significantly more abundant in fertilized plots compared to non-fertilized plots. Hence, this study provided novel insights into changes in dynamics and functions of soil bacterial communities as response to season and fertilizer application. PMID:26694644

  12. Effects of Fertilization and Sampling Time on Composition and Diversity of Entire and Active Bacterial Communities in German Grassland Soils.

    PubMed

    Herzog, Sarah; Wemheuer, Franziska; Wemheuer, Bernd; Daniel, Rolf

    2015-01-01

    Soil bacteria are major players in driving and regulating ecosystem processes. Thus, the identification of factors shaping the diversity and structure of these communities is crucial for understanding bacterial-mediated processes such as nutrient transformation and cycling. As most studies only target the entire soil bacterial community, the response of active community members to environmental changes is still poorly understood. The objective of this study was to investigate the effect of fertilizer application and sampling time on structure and diversity of potentially active (RNA-based) and the entire (DNA-based) bacterial communities in German grassland soils. Analysis of more than 2.3 million 16S rRNA transcripts and gene sequences derived from amplicon-based sequencing of 16S rRNA genes revealed that fertilizer application and sampling time significantly altered the diversity and composition of entire and active bacterial communities. Although the composition of both the entire and the active bacterial community was correlated with environmental factors such as pH or C/N ratio, the active community showed a higher sensitivity to environmental changes than the entire community. In addition, functional analyses were performed based on predictions derived from 16S rRNA data. Genes encoding the uptake of nitrate/nitrite, nitrification, and denitrification were significantly more abundant in fertilized plots compared to non-fertilized plots. Hence, this study provided novel insights into changes in dynamics and functions of soil bacterial communities as response to season and fertilizer application. PMID:26694644

  13. High-throughput diagnosis of potato cyst nematodes in soil samples.

    PubMed

    Reid, Alex; Evans, Fiona; Mulholland, Vincent; Cole, Yvonne; Pickup, Jon

    2015-01-01

    Potato cyst nematode (PCN) is a damaging soilborne pest of potatoes which can cause major crop losses. In 2010, a new European Union directive (2007/33/EC) on the control of PCN came into force. Under the new directive, seed potatoes can only be planted on land which has been found to be free from PCN infestation following an official soil test. A major consequence of the new directive was the introduction of a new harmonized soil sampling rate resulting in a threefold increase in the number of samples requiring testing. To manage this increase with the same staffing resources, we have replaced the traditional diagnostic methods. A system has been developed for the processing of soil samples, extraction of DNA from float material, and detection of PCN by high-throughput real-time PCR. Approximately 17,000 samples are analyzed each year using this method. This chapter describes the high-throughput processes for the production of float material from soil samples, DNA extraction from the entire float, and subsequent detection and identification of PCN within these samples. PMID:25981252

  14. Sampling the soil in long-term forest plots: the implications of spatial variation.

    PubMed

    Kirwan, N; Oliver, M A; Moffat, A J; Morgan, G W

    2005-12-01

    Long-term monitoring of forest soils as part of a pan-European network to detect environmental change depends on an accurate determination of the mean of the soil properties at each monitoring event. Forest soil is known to be very variable spatially, however. A study was undertaken to explore and quantify this variability at three forest monitoring plots in Britain. Detailed soil sampling was carried out, and the data from the chemical analyses were analysed by classical statistics and geostatistics. An analysis of variance showed that there were no consistent effects from the sample sites in relation to the position of the trees. The variogram analysis showed that there was spatial dependence at each site for several variables and some varied in an apparently periodic way. An optimal sampling analysis based on the multivariate variogram for each site suggested that a bulked sample from 36 cores would reduce error to an acceptable level. Future sampling should be designed so that it neither targets nor avoids trees and disturbed ground. This can be achieved best by using a stratified random sampling design. PMID:16311827

  15. High-throughput diagnosis of potato cyst nematodes in soil samples.

    PubMed

    Reid, Alex; Evans, Fiona; Mulholland, Vincent; Cole, Yvonne; Pickup, Jon

    2015-01-01

    Potato cyst nematode (PCN) is a damaging soilborne pest of potatoes which can cause major crop losses. In 2010, a new European Union directive (2007/33/EC) on the control of PCN came into force. Under the new directive, seed potatoes can only be planted on land which has been found to be free from PCN infestation following an official soil test. A major consequence of the new directive was the introduction of a new harmonized soil sampling rate resulting in a threefold increase in the number of samples requiring testing. To manage this increase with the same staffing resources, we have replaced the traditional diagnostic methods. A system has been developed for the processing of soil samples, extraction of DNA from float material, and detection of PCN by high-throughput real-time PCR. Approximately 17,000 samples are analyzed each year using this method. This chapter describes the high-throughput processes for the production of float material from soil samples, DNA extraction from the entire float, and subsequent detection and identification of PCN within these samples.

  16. DNA-based determination of microbial biomass suitable for frozen and alkaline soil samples

    NASA Astrophysics Data System (ADS)

    Semenov, Mikhail; Blagodatskaya, Evgeniya; Kogut, Boris; Kuzyakov, Yakov

    2015-04-01

    Microbial biomass is a sensitive indicator of changes due to soil management, long before other basic soil measures such as Corg or Ntot. Improvement of methods for determination of microbial biomass still remains relevant, and these methods should be correctly applicable for the soil samples being in various state. This study was designed to demonstrate the applicability of DNA-based determination of microbial biomass under conditions when the common basic approaches, namely chloroform fumigation-extraction (CFE) and substrate-induced respiration (SIR), are restricted by certain soil properties, experimental designs or research needs, e.g. in frozen, alkaline or carbonaceous soils. We compared microbial biomass determined by CFE, SIR and by DNA approaches in the range of neutral and slightly alkaline Chernozem and alkaline Calcisol of semi-arid climate. The samples of natural and agricultural ecosystems were taken throughout the soil profile from long-term static field experiments in the European part of Russia. Extraction and subsequent quantification of dsDNA revealed a strong agreement with SIR and CFE when analyzing the microbial biomass content in soils with pH below 8. The conversion factors (FDNA) from dsDNA to SIR-Cmic (5.10) and CFE-Cmic (4.41) were obtained by testing a range of the soil samples down to 1.5 m depth and indicated a good reproducibility of DNA-based estimations. In alkaline soils (pH > 8), CO2 retention due to alkaline pH and exchange with carbonates resulted in a strong underestimation of soil microbial biomass by SIR or even in the absence of any CO2 emission, especially at low absolute values of microbial biomass in subsoil. Correction of CO2 efflux by theoretical retention pH-dependent factors caused overestimation of SIR-biomass. In alkaline conditions, DNA extraction proved to be a reliable alternative for microbial biomass determination. Moreover, the DNA-based approach can serve as an excellent alternative enabling correct

  17. Geochemical and mineralogical evidence for Sahara and Sahel dust additions to Quaternary soils on Lanzarote, eastern Canary Islands, Spain

    USGS Publications Warehouse

    Muhs, D.R.; Budahn, J.; Skipp, G.; Prospero, J.M.; Patterson, D.; Bettis, E. Arthur

    2010-01-01

    Africa is the most important source of dust in the world today, and dust storms are frequent on the nearby Canary Islands. Previous workers have inferred that the Sahara is the most important source of dust to Canary Islands soils, with little contribution from the Sahel region. Soils overlying a late Quaternary basalt flow on Lanzarote, Canary Islands, contain, in addition to volcanic minerals, quartz and mica, exotic to the island's bedrock. Kaolinite in the soils also likely has an exotic origin. Trace-element geochemistry shows that the soils are derived from varying proportions of locally derived basalt and African dust. Major-element geochemistry, clay mineralogy and interpretation of satellite imagery suggest that dust additions to the Canary Islands come not only from the Sahara Desert, but also from the Sahel region. ?? Published 2010. This article is a US Government work and is in the public domain in the USA.

  18. Diversity of bacteria producing pigmented colonies in aerosol, snow and soil samples from remote glacial areas (Antarctica, Alps and Andes)

    NASA Astrophysics Data System (ADS)

    González-Toril, E.; Amils, R.; Delmas, R. J.; Petit, J.-R.; Komárek, J.; Elster, J.

    2008-04-01

    Four different communities and one culture of pigmented microbial assemblages were obtained by incubation in mineral medium of samples collected from high elevation snow in the Alps (Mt. Blanc area) and the Andes (Nevado Illimani summit, Bolivia), from Antarctic aerosol (French station Dumont d'Urville) and a maritime Antarctic soil (King George Island, South Shetlands, Uruguay Station Artigas). Molecular analysis of more than 200 16S rRNA gene sequences showed that all cultured cells belong to the Bacteria domain. The phylogenetic comparison with the currently available rDNA database allowed the identification of sequences belonging to Proteobacteria (Alpha-, Beta- and Gamma-proteobacteria), Actinobacteria and Bacteroidetes phyla. The Andes snow culture was the richest in bacterial diversity (eight microorganisms identified) and the maritime Antarctic soil the poorest (only one). Snow samples from Col du midi (Alps) and the Andes shared the highest number of identified microorganisms (Agrobacterium, Limnobacter, Aquiflexus and two uncultured Alphaproteobacteria clones). These two sampling sites also shared four sequences with the Antarctic aerosol sample (Limnobacter, Pseudonocardia and an uncultured Alphaproteobacteria clone). The only microorganism identified in the maritime Antarctica soil (Brevundimonas sp.) was also detected in the Antarctic aerosol. The two snow samples from the Alps only shared one common microorganism. Most of the identified microorganisms have been detected previously in cold environments (Dietzia kujamenisi, Pseudonocardia Antarctica, Hydrogenophaga palleronii and Brebundimonas sp.), marine sediments (Aquiflexus balticus, Pseudomonas pseudoalkaligenes, Pseudomonas sp. and one uncultured Alphaproteobacteria), and soils and rocks (Pseudonocardia sp., Agrobactrium sp., Limnobacter sp. and two uncultured Alphaproteobacetria clones). Air current dispersal is the best model to explain the presence of very specific microorganisms, like those

  19. Sensitive and rapid quantitative detection of anthrax spores isolated from soil samples by real-time PCR.

    PubMed

    Ryu, Chunsun; Lee, Kyunghee; Yoo, Cheonkwon; Seong, Won Keun; Oh, Hee-Bok

    2003-01-01

    Quantitative analysis of anthrax spores from environmental samples is essential for accurate detection and risk assessment since Bacillus anthracis spores have been shown to be one of the most effective biological weapons. Using TaqMan real-time PCR, specific primers and probes were designed for the identification of pathogenic B. anthracis strains from pag gene and cap gene on two plasmids, pXO1 and pXO2, as well as a sap gene encoded on the S-layer. To select the appropriate lysis method of anthrax spore from environmental samples, several heat treatments and germination methods were evaluated with multiplex-PCR. Among them, heat treatment of samples suspended with sucrose plus non-ionic detergent was considered an effective spore disruption method because it detected up to 10(5) spores/g soil by multiplex-PCR. Serial dilutions of B. anthracis DNA and spore were detected up to a level of 0.1 ng/ microliters and 10 spores/ml, respectively, at the correlation coefficient of 0.99 by real-time PCR. Quantitative analysis of anthrax spore could be obtained from the comparison between C(T) value and serial dilutions of soil sample at the correlation coefficient of 0.99. Additionally, spores added to soil samples were detected up to 10(4) spores/g soil within 3 hr by real-time PCR. As a consequence, we established a rapid and accurate detection system for environmental anthrax spores using real-time PCR, avoiding time and labor-consuming preparation steps such as enrichment culturing and DNA preparation.

  20. Carbon stabilization and microbial growth in acidic mine soils after addition of different amendments for soil reclamation

    NASA Astrophysics Data System (ADS)

    Zornoza, Raúl; Acosta, Jose; Ángeles Muñoz, María; Martínez-Martínez, Silvia; Faz, Ángel; Bååth, Erland

    2016-04-01

    The extreme soil conditions in metalliferous mine soils have a negative influence on soil biological activity and therefore on soil carbon estabilization. Therefore, amendments are used to increase organic carbon content and activate microbial communities. In order to elucidate some of the factors controlling soil organic carbon stabilization in reclaimed acidic mine soils and its interrelationship with microbial growth and community structure, we performed an incubation experiment with four amendments: pig slurry (PS), pig manure (PM) and biochar (BC), applied with and without marble waste (MW; CaCO3). Results showed that PM and BC (alone or together with MW) contributed to an important increment in recalcitrant organic C, C/N ratio and aggregate stability. Bacterial and fungal growths were highly dependent on pH and labile organic C. PS supported the highest microbial growth; applied alone it stimulated fungal growth, and applied with MW it stimulated bacterial growth. BC promoted the lowest microbial growth, especially for fungi, with no significant increase in fungal biomass. MW+BC increased bacterial growth up to values similar to PM and MW+PM, suggesting that part of the biochar was degraded, at least in short-term mainly by bacteria rather than fungi. PM, MW+PS and MW+PM supported the highest microbial biomass and a similar community structure, related with the presence of high organic C and high pH, with immobilization of metals and increased soil quality. BC contributed to improved soil structure, increased recalcitrant organic C, and decreased metal mobility, with low stimulation of microbial growth.

  1. A Needed Paradigm Change for Environmental Soil Sampling at Urban Sites

    NASA Astrophysics Data System (ADS)

    Clausen, J. L.; Bednar, A. J.

    2015-12-01

    Heterogeneous distribution of solid contaminant residues in surface soils creates an unique challenge for collecting soil samples yielding representative and reproducible results. Research over the past decade involving energetic and metallic residues indicates conventional grab sampling yields unreproducible, biased, results with poor precision non-representative of site conditions. Spatially, grab sampling yields information only about the point sampled. However, risk assessment and remedial decisions are based on contaminant distribution over an area. Multiple grab samples are collected for spatial coverage with the number often based on "expert opinion". Recent research suggests new field sampling and laboratory processing procedures encompassed in the Incremental Sampling Methodology (ISM) and incorporated into United States Environmental Protection (USEPA) Method 8330B for energetics and the update to Method 3050B for metals are necessary to overcome heterogeneity issues. The ISM approach is different from conventional grab sampling due to the focus on a spatially averaged result over a decision unit (DU) obtained by the collection of many increments using a systematic random sampling approach to form a single sample. Total precision error using ISM is typically <30%, whereas relative errors > 100% are observed between field splits and laboratory replicates with conventional grab sampling. Field splitting often employed prior to laboratory sample processing resulted in poor precision and is not recommended. Milling or grinding of soil samples is necessary to reduce the total error of the sample and to obtain acceptable precision, especially in situations where the mean contaminant concentration is expected to be near the action level or other regulatory value.

  2. Determination of naturally occurring radionuclides in soil samples of Ayranci, Turkey

    NASA Astrophysics Data System (ADS)

    Agar, Osman; Eke, Canel; Boztosun, Ismail; Emin Korkmaz, M.

    2015-04-01

    The specific activity, radiation hazard index and the annual effective dose of the naturally occurring radioactive elements (238U, 232Th and 40K) were determined in soil samples collected from 12 different locations in Ayranci region by using a NaI(Tl) gamma-ray spectrometer. The measured activity concentrations of the natural radionuclides in studied soil samples were compared with the corresponding results of different countries and the internationally reported values. From the analysis, it is found that these materials may be safely used as construction materials and do not pose significant radiation hazards.

  3. Impacts of woodchip biochar additions on greenhouse gas production and sorption/degradation of two herbicides in a Minnesota soil.

    PubMed

    Spokas, K A; Koskinen, W C; Baker, J M; Reicosky, D C

    2009-10-01

    A potential abatement to increasing levels of carbon dioxide (CO(2)) in the atmosphere is the use of pyrolysis to convert vegetative biomass into a more stable form of carbon (biochar) that could then be applied to the soil. However, the impacts of pyrolysis biochar on the soil system need to be assessed before initiating large scale biochar applications to agricultural fields. We compared CO(2) respiration, nitrous oxide (N(2)O) production, methane (CH(4)) oxidation and herbicide retention and transformation through laboratory incubations at field capacity in a Minnesota soil (Waukegan silt loam) with and without added biochar. CO(2) originating from the biochar needs to be subtracted from the soil-biochar combination in order to elucidate the impact of biochar on soil respiration. After this correction, biochar amendments reduced CO(2) production for all amendment levels tested (2, 5, 10, 20, 40 and 60% w/w; corresponding to 24-720 tha(-1) field application rates). In addition, biochar additions suppressed N(2)O production at all levels. However, these reductions were only significant at biochar amendment levels >20% w/w. Biochar additions also significantly suppressed ambient CH(4) oxidation at all levels compared to unamended soil. The addition of biochar (5% w/w) to soil increased the sorption of atrazine and acetochlor compared to non-amended soils, resulting in decreased dissipation rates of these herbicides. The recalcitrance of the biochar suggests that it could be a viable carbon sequestration strategy, and might provide substantial net greenhouse gas benefits if the reductions in N(2)O production are lasting.

  4. EDTA addition enhances bacterial respiration activities and hydrocarbon degradation in bioaugmented and non-bioaugmented oil-contaminated desert soils.

    PubMed

    Al Kharusi, Samiha; Abed, Raeid M M; Dobretsov, Sergey

    2016-03-01

    The low number and activity of hydrocarbon-degrading bacteria and the low solubility and availability of hydrocarbons hamper bioremediation of oil-contaminated soils in arid deserts, thus bioremediation treatments that circumvent these limitations are required. We tested the effect of Ethylenediaminetetraacetic acid (EDTA) addition, at different concentrations (i.e. 0.1, 1 and 10 mM), on bacterial respiration and biodegradation of Arabian light oil in bioaugmented (i.e. with the addition of exogenous alkane-degrading consortium) and non-bioaugmented oil-contaminated desert soils. Post-treatment shifts in the soils' bacterial community structure were monitored using MiSeq sequencing. Bacterial respiration, indicated by the amount of evolved CO2, was highest at 10 mM EDTA in bioaugmented and non-bioaugmented soils, reaching an amount of 2.2 ± 0.08 and 1.6 ± 0.02 mg-CO2 g(-1) after 14 days of incubation, respectively. GC-MS revealed that 91.5% of the C14-C30 alkanes were degraded after 42 days when 10 mM EDTA and the bacterial consortium were added together. MiSeq sequencing showed that 78-91% of retrieved sequences in the original soil belonged to Deinococci, Alphaproteobacteria, Gammaproteobacteia and Bacilli. The same bacterial classes were detected in the 10 mM EDTA-treated soils, however with slight differences in their relative abundances. In the bioaugmented soils, only Alcanivorax sp. MH3 and Parvibaculum sp. MH21 from the exogenous bacterial consortium could survive until the end of the experiment. We conclude that the addition of EDTA at appropriate concentrations could facilitate biodegradation processes by increasing hydrocarbon availability to microbes. The addition of exogenous oil-degrading bacteria along with EDTA could serve as an ideal solution for the decontamination of oil-contaminated desert soils.

  5. A model for estimating the value of sampling programs and the optimal number of samples for contaminated soil

    NASA Astrophysics Data System (ADS)

    Back, Pär-Erik

    2007-04-01

    A model is presented for estimating the value of information of sampling programs for contaminated soil. The purpose is to calculate the optimal number of samples when the objective is to estimate the mean concentration. A Bayesian risk-cost-benefit decision analysis framework is applied and the approach is design-based. The model explicitly includes sample uncertainty at a complexity level that can be applied to practical contaminated land problems with limited amount of data. Prior information about the contamination level is modelled by probability density functions. The value of information is expressed in monetary terms. The most cost-effective sampling program is the one with the highest expected net value. The model was applied to a contaminated scrap yard in Göteborg, Sweden, contaminated by metals. The optimal number of samples was determined to be in the range of 16-18 for a remediation unit of 100 m2. Sensitivity analysis indicates that the perspective of the decision-maker is important, and that the cost of failure and the future land use are the most important factors to consider. The model can also be applied for other sampling problems, for example, sampling and testing of wastes to meet landfill waste acceptance procedures.

  6. Guidance for characterizing explosives contaminated soils: Sampling and selecting on-site analytical methods

    SciTech Connect

    Crockett, A.B.; Craig, H.D.; Jenkins, T.F.; Sisk, W.E.

    1996-09-01

    A large number of defense-related sites are contaminated with elevated levels of secondary explosives. Levels of contamination range from barely detectable to levels above 10% that need special handling due to the detonation potential. Characterization of explosives-contaminated sites is particularly difficult due to the very heterogeneous distribution of contamination in the environment and within samples. To improve site characterization, several options exist including collecting more samples, providing on-site analytical data to help direct the investigation, compositing samples, improving homogenization of samples, and extracting larger samples. On-site analytical methods are essential to more economical and improved characterization. On-site methods might suffer in terms of precision and accuracy, but this is more than offset by the increased number of samples