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Sample records for measured soil properties

  1. Measurement of dielectric and magnetic properties of soil

    International Nuclear Information System (INIS)

    Patitz, W.E.; Brock, B.C.; Powell, E.G.

    1995-11-01

    The possibility of subsurface imaging using SAR technology has generated a considerable amount of interest in recent years. One requirement for the successful development of a subsurface imagin system is an understanding of how the soil affects the signal. In response to a need for an electromagnetic characterization of the soil properties, the Radar/Antenna department has developed a measurement system which determines the soils complex electric permittivity and magnetic permeability at UHF frequencies. The one way loss in dB is also calculated using the measured values. There are many reports of measurements of the electric properties of soil in the literature. However, most of these are primarily concerned with measuring only a real dielectric constant. Because some soils have ferromagnetic constituents it is desirable to measure both the electric and magnetic properties of the soil

  2. Using 137 Cs measurements to investigate the influence of erosion and soil redistribution on soil properties.

    Science.gov (United States)

    Du, P; Walling, D E

    2011-05-01

    Information on the interaction between soil erosion and soil properties is an important requirement for sustainable management of the soil resource. The relationship between soil properties and the soil redistribution rate, reflecting both erosion and deposition, is an important indicator of this interaction. This relationship is difficult to investigate using traditional approaches to documenting soil redistribution rates involving erosion plots and predictive models. However, the use of the fallout radionuclide (137)Cs to document medium-term soil redistribution rates offers a means of overcoming many of the limitations associated with traditional approaches. The study reported sought to demonstrate the potential for using (137)Cs measurements to assess the influence of soil erosion and redistribution on soil properties (particle size composition, total C, macronutrients N, P, K and Mg, micronutrients Mn, Mo, Fe, Cu and Zn and other elements, including Ti and As). (137)Cs measurements undertaken on 52 soil cores collected within a 7 ha cultivated field located near Colebrooke in Devon, UK were used to establish the magnitude and spatial pattern of medium-term soil redistribution rates within the field. The soil redistribution rates documented for the individual sampling points within the field ranged from an erosion rate of -12.9 t ha(-1) yr(-1) to a deposition rate of 19.2 t ha(-1) yr(-1). Composite samples of surface soil (0-5 cm) were collected immediately adjacent to each coring point and these samples were analysed for a range of soil properties. Individual soil properties associated with these samples showed significant variability, with CV values generally lying in the range 10-30%. The relationships between the surface soil properties and the soil redistribution rate were analysed. This analysis demonstrated statistically significant relationships between some soil properties (total phosphorus, % clay, Ti and As) and the soil redistribution rate, but for

  3. Using 137Cs measurements to investigate the influence of erosion and soil redistribution on soil properties

    International Nuclear Information System (INIS)

    Du, P.; Walling, D.E.

    2011-01-01

    Information on the interaction between soil erosion and soil properties is an important requirement for sustainable management of the soil resource. The relationship between soil properties and the soil redistribution rate, reflecting both erosion and deposition, is an important indicator of this interaction. This relationship is difficult to investigate using traditional approaches to documenting soil redistribution rates involving erosion plots and predictive models. However, the use of the fallout radionuclide 137 Cs to document medium-term soil redistribution rates offers a means of overcoming many of the limitations associated with traditional approaches. The study reported sought to demonstrate the potential for using 137 Cs measurements to assess the influence of soil erosion and redistribution on soil properties (particle size composition, total C, macronutrients N, P, K and Mg, micronutrients Mn, Mo, Fe, Cu and Zn and other elements, including Ti and As). 137 Cs measurements undertaken on 52 soil cores collected within a 7 ha cultivated field located near Colebrooke in Devon, UK were used to establish the magnitude and spatial pattern of medium-term soil redistribution rates within the field. The soil redistribution rates documented for the individual sampling points within the field ranged from an erosion rate of -12.9 t ha -1 yr -1 to a deposition rate of 19.2 t ha -1 yr -1 . Composite samples of surface soil (0-5 cm) were collected immediately adjacent to each coring point and these samples were analysed for a range of soil properties. Individual soil properties associated with these samples showed significant variability, with CV values generally lying in the range 10-30%. The relationships between the surface soil properties and the soil redistribution rate were analysed. This analysis demonstrated statistically significant relationships between some soil properties (total phosphorus, % clay, Ti and As) and the soil redistribution rate, but for most

  4. Measurement of thermal properties of soil and concrete samples

    DEFF Research Database (Denmark)

    Pagola, Maria Alberdi; Jensen, Rasmus Lund; Madsen, Søren

    February 2016 and February 2017. The presented work mainly consists of thermal property measurements. They become important as they form the basis for dimensioning a planned ground source heat pump installation based on closed loop vertical ground heat exchangers. This report complements the report......, the measurements of the properties of the concrete are treated. The work is extended in appendixes.......This document aims to present the laboratory work undertaken to analyse the thermal properties of the soil at two test sites in Denmark and the concrete produced by Centrum Pæle A/S, used to produce the pile heat exchangers studied in the present PhD project. The tasks have been carried out between...

  5. Characterization of field-measured soil-water properties

    International Nuclear Information System (INIS)

    Nielsen, D.R.; Reichardt, K.; Wierenga, P.J.

    1983-01-01

    As part of a five-year co-ordinated research programme of the International Atomic Energy Agency, the Use of Radiation and Isotope Techniques in Studies of Soil-Water Regimes, soil physicists examined soil-water properties of one or two field sites in 11 different countries (Brazil, Belgium, Cyprus, Chile, Israel, Japan, Madagascar, Nigeria, Senegal, Syria and Thailand). The results indicate that the redistribution method yields values of soil-water properties that have a large degree of uncertainty, and that this uncertainty is not necessarily related to the kind of soil being analysed. Regardless of the fundamental cause of this uncertainty (experimental and computational errors versus natural soil variability), the conclusion is that further developments of field technology depend upon stochastic rather than deterministic concepts

  6. Field soil-water properties measured through radiation techniques

    International Nuclear Information System (INIS)

    1984-07-01

    This report shows a major effort to make soil physics applicable to the behaviour of the field soils and presents a rich and diverse set of data which are essential for the development of effective soil-water management practices that improve and conserve the quality and quantity of agricultural lands. This piece of research has shown that the neutron moisture meter together with some complementary instruments like tensiometers, can be used not only to measure soil water contents but also be extremely handy to measure soil hydraulic characteristics and soil water flow. It is, however, recognized that hydraulic conductivity is highly sensitive to small changes in soil water content and texture, being extremely variable spatially and temporally

  7. Using {sup 137}Cs measurements to investigate the influence of erosion and soil redistribution on soil properties

    Energy Technology Data Exchange (ETDEWEB)

    Du, P. [School of Geography, Beijing Normal University, Beijing (China); Geography, College of Life and Environmental Sciences, University of Exeter, Amory Building, Rennes Drive, Exeter, EX4 4RJ, Devon (United Kingdom); Walling, D.E., E-mail: d.e.walling@exeter.ac.u [Geography, College of Life and Environmental Sciences, University of Exeter, Amory Building, Rennes Drive, Exeter, EX4 4RJ, Devon (United Kingdom)

    2011-05-15

    Information on the interaction between soil erosion and soil properties is an important requirement for sustainable management of the soil resource. The relationship between soil properties and the soil redistribution rate, reflecting both erosion and deposition, is an important indicator of this interaction. This relationship is difficult to investigate using traditional approaches to documenting soil redistribution rates involving erosion plots and predictive models. However, the use of the fallout radionuclide {sup 137}Cs to document medium-term soil redistribution rates offers a means of overcoming many of the limitations associated with traditional approaches. The study reported sought to demonstrate the potential for using {sup 137}Cs measurements to assess the influence of soil erosion and redistribution on soil properties (particle size composition, total C, macronutrients N, P, K and Mg, micronutrients Mn, Mo, Fe, Cu and Zn and other elements, including Ti and As). {sup 137}Cs measurements undertaken on 52 soil cores collected within a 7 ha cultivated field located near Colebrooke in Devon, UK were used to establish the magnitude and spatial pattern of medium-term soil redistribution rates within the field. The soil redistribution rates documented for the individual sampling points within the field ranged from an erosion rate of -12.9 t ha{sup -1} yr{sup -1} to a deposition rate of 19.2 t ha{sup -1} yr{sup -1}. Composite samples of surface soil (0-5 cm) were collected immediately adjacent to each coring point and these samples were analysed for a range of soil properties. Individual soil properties associated with these samples showed significant variability, with CV values generally lying in the range 10-30%. The relationships between the surface soil properties and the soil redistribution rate were analysed. This analysis demonstrated statistically significant relationships between some soil properties (total phosphorus, % clay, Ti and As) and the soil

  8. Measurement of soil lead bioavailability and influence of soil types and properties: A review.

    Science.gov (United States)

    Yan, Kaihong; Dong, Zhaomin; Wijayawardena, M A Ayanka; Liu, Yanju; Naidu, Ravi; Semple, Kirk

    2017-10-01

    Lead (Pb) is a widespread heavy metal which is harmful to human health, especially to young children. To provide a human health risk assessment that is more relevant to real conditions, Pb bioavailability in soils is increasingly employed in the assessment procedure. Both in vivo and in vitro measurements for lead bioavailability are available. In vivo models are time- consuming and expensive, while in vitro models are rapid, economic, reproducible, and reliable while involving more uncertainties. Uncertainties in various measurements create difficulties in accurately predicting Pb bioavailability, resulting in the unnecessary remediation of sites. In this critical review, we utilised available data from in vivo and in vitro studies to identify the key parameters influencing the in vitro measurements, and presented uncertainties existing in Pb bioavailability measurements. Soil type, properties and metal content are reported to influence lead bioavailability; however, the differences in methods for assessing bioavailability and the differences in Pb source limit one's ability to conduct statistical analyses on influences of soil factors on Pb bioavailability. The information provided in the review is fundamentally useful for the measurement of bioavailability and risk assessment practices. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Measuring Static and Dynamic Properties of Frozen Silty Soils

    Energy Technology Data Exchange (ETDEWEB)

    Furnish, M.D.

    1998-09-30

    A mechanical characterization of frozen silty soils has been conducted to support computer modeling of penetrators. The soils were obtained from the Eilson AFB (Alaska) vicinity. Quasi-static testing with a multiaxial system in a cold room and intermediate strain rate testing with a split Hopkinson pressure bar were conducted. Maximum stresses achieved were slightly above 1 GPa, apparently limiting the observed behavior primarily to elastic compression and pore crushing phenomena. Lower temperatures seem to increase the strength of the material markedly, although not by a simple factor. Lower temperatures and higher strain rates increase the apparent Young's and bulk moduli as well (an increase of {approximately} a factor of two is observed for strain rate increasing from 0.001 s{sup {minus}1} to 800 s{sup {minus}1}). The strength also depends strongly on strain rate. Increasing the strain rate from 0.001 {sup {minus}1} to 0.07 {sup {minus}1} increases the strength by a factor of five to ten (to values of order 1 GPa). However,only a small increase in strength is seen as strain rate is increased to {approximately} 10{sup 2}--10{sup 3} s{sup {minus}1}. The reliability of the strength measurements at strain rates< 1 s{sup {minus}1} is decreased due to details of the experimental geometry, although general trends are observable. A recipe is provided for a simulant soil based on bentonite, sand, clay-rich soil and water to fit the {approximately} 6% air-filled porosity, density and water content of the Alaska soils, based on benchtop mixing and jacketed compression testing of candidate mixes.

  10. A non-destructive method to measure the thermal properties of frozen soils during phase transition

    Directory of Open Access Journals (Sweden)

    Bin Zhang

    2015-04-01

    Full Text Available Frozen soils cover about 40% of the land surface on the earth and are responsible for the global energy balances affecting the climate. Measurement of the thermal properties of frozen soils during phase transition is important for analyzing the thermal transport process. Due to the involvement of phase transition, the thermal properties of frozen soils are rather complex. This paper introduces the uses of a multifunctional instrument that integrates time domain reflectometry (TDR sensor and thermal pulse technology (TPT to measure the thermal properties of soil during phase transition. With this method, the extent of phase transition (freezing/thawing was measured with the TDR module; and the corresponding thermal properties were measured with the TPT module. Therefore, the variation of thermal properties with the extent of freezing/thawing can be obtained. Wet soils were used to demonstrate the performance of this measurement method. The performance of individual modules was first validated with designed experiments. The new sensor was then used to monitor the properties of soils during freezing–thawing process, from which the freezing/thawing degree and thermal properties were simultaneously measured. The results are consistent with documented trends of thermal properties variations.

  11. Evaluating lysimeter drainage against soil deep percolation modeled with profile soil moisture, field tracer propagation, and lab measured soil hydraulic properties

    DEFF Research Database (Denmark)

    Vasquez, Vicente; Thomsen, Anton Gårde; Iversen, Bo Vangsø

    them have been reported. To compare among methods, one year of four large-scale lysimeters drainage (D) was evaluated against modeled soil deep percolation using either profile soil moisture, bromide breakthrough curves from suction cups, or measured soil hydraulic properties in the laboratory....... Measured volumetric soil water content (q) was 3-4% higher inside lysimeters than in the field probably due to a zero tension lower boundary condition inside lysimeters. D from soil hydraulic properties measured in the laboratory resulted in a 15% higher evapotranspiration and 12% lower drainage...... predictions than the model calibrated with field measured q. Bromide (Br) breakthrough curves indicated high variability between lysimeters and field suction cups with mean Br velocities at first arrival time of 110 and 33 mm/d, respectively. D was 520 mm/yr with lysimeters, 613 mm/yr with the calibrated...

  12. Soil Electromagnetic Properties and Metal Detector Performance: Theory and Measurement

    Science.gov (United States)

    2008-11-17

    configuration on 51 a uniform conductive half-space are predicted by the following relation reported by Oldenburg (1978) S(r, z) = s(r1, z)− s(r2, z)− s(r3...where γQ denotes an instrument-specific scaling factor. In complete analogy with sensitivity functions described for quadrapole electrode ar- rays ...www.bartington.com/media/aedd335c/om0408%20MS2%20v46.pdf Billings, S.D., Pasion, L.R. and Oldenburg , D.W., 2003, Characterizing magnetic soils: state of the art and

  13. Hanford Sludge Simulant Selection for Soil Mechanics Property Measurement

    Energy Technology Data Exchange (ETDEWEB)

    Wells, Beric E.; Russell, Renee L.; Mahoney, Lenna A.; Brown, Garrett N.; Rinehart, Donald E.; Buchmiller, William C.; Golovich, Elizabeth C.; Crum, Jarrod V.

    2010-03-23

    The current System Plan for the Hanford Tank Farms uses relaxed buoyant displacement gas release event (BDGRE) controls for deep sludge (i.e., high level waste [HLW]) tanks, which allows the tank farms to use more storage space, i.e., increase the sediment depth, in some of the double-shell tanks (DSTs). The relaxed BDGRE controls are based on preliminary analysis of a gas release model from van Kessel and van Kesteren. Application of the van Kessel and van Kesteren model requires parametric information for the sediment, including the lateral earth pressure at rest and shear modulus. No lateral earth pressure at rest and shear modulus in situ measurements for Hanford sludge are currently available. The two chemical sludge simulants will be used in follow-on work to experimentally measure the van Kessel and van Kesteren model parameters, lateral earth pressure at rest, and shear modulus.

  14. Hanford Sludge Simulant Selection for Soil Mechanics Property Measurement

    International Nuclear Information System (INIS)

    Wells, Beric E.; Russell, Renee L.; Mahoney, Lenna A.; Brown, Garrett N.; Rinehart, Donald E.; Buchmiller, William C.; Golovich, Elizabeth C.; Crum, Jarrod V.

    2010-01-01

    The current System Plan for the Hanford Tank Farms uses relaxed buoyant displacement gas release event (BDGRE) controls for deep sludge (i.e., high level waste (HLW)) tanks, which allows the tank farms to use more storage space, i.e., increase the sediment depth, in some of the double-shell tanks (DSTs). The relaxed BDGRE controls are based on preliminary analysis of a gas release model from van Kessel and van Kesteren. Application of the van Kessel and van Kesteren model requires parametric information for the sediment, including the lateral earth pressure at rest and shear modulus. No lateral earth pressure at rest and shear modulus in situ measurements for Hanford sludge are currently available. The two chemical sludge simulants will be used in follow-on work to experimentally measure the van Kessel and van Kesteren model parameters, lateral earth pressure at rest, and shear modulus.

  15. Measurement of Physical and Hydraulic Properties of Organic Soil Using Computed Tomographic Imagery

    Science.gov (United States)

    Blais, K. E.; Quinton, W. L.; Heck, R. J.; Price, J. S.; Schmidt, M. G.

    2005-12-01

    The Lower Liard River valley is located within the continental northern boreal region and the zone of discontinuous permafrost. Lying in the centre of the Mackenzie basin, this valley is an extensive flat headwater region with a high density of open water and peatlands. Several standard methods of measuring the physical properties of organic soils exist, although many of them have several drawbacks that limit their use. Organic soils, in particular, have unique properties that require special attention to ensure that the measured hydrological characteristics are represented as they exist in nature. The goal of this research was to devise an improved method of analyzing and measuring the physical and hydraulic properties of organic soil using MicroCT imagery. Specifically, this research seeks to determine if two and three-dimensional images of peat can be used to accurately characterize air-filled porosity, active porosity, pore size distribution, pore saturated area and capillarity of porous Sphagnum cells. Results indicate that measurements derived from these images are consistent with current literature. They also suggest that this non-destructive method is a valuable tool for measuring peat physical and hydraulic properties and that there is potential for additional research using CT technology.

  16. In situ measurement of some soil properties in paddy soil using visible and near-infrared spectroscopy.

    Directory of Open Access Journals (Sweden)

    Ji Wenjun

    Full Text Available In situ measurements with visible and near-infrared spectroscopy (vis-NIR provide an efficient way for acquiring soil information of paddy soils in the short time gap between the harvest and following rotation. The aim of this study was to evaluate its feasibility to predict a series of soil properties including organic matter (OM, organic carbon (OC, total nitrogen (TN, available nitrogen (AN, available phosphorus (AP, available potassium (AK and pH of paddy soils in Zhejiang province, China. Firstly, the linear partial least squares regression (PLSR was performed on the in situ spectra and the predictions were compared to those with laboratory-based recorded spectra. Then, the non-linear least-square support vector machine (LS-SVM algorithm was carried out aiming to extract more useful information from the in situ spectra and improve predictions. Results show that in terms of OC, OM, TN, AN and pH, (i the predictions were worse using in situ spectra compared to laboratory-based spectra with PLSR algorithm (ii the prediction accuracy using LS-SVM (R2>0.75, RPD>1.90 was obviously improved with in situ vis-NIR spectra compared to PLSR algorithm, and comparable or even better than results generated using laboratory-based spectra with PLSR; (iii in terms of AP and AK, poor predictions were obtained with in situ spectra (R2<0.5, RPD<1.50 either using PLSR or LS-SVM. The results highlight the use of LS-SVM for in situ vis-NIR spectroscopic estimation of soil properties of paddy soils.

  17. Mini Tensiometer-Time Domain Reflectometry Coil Probe for Measuring Soil Water Retention Properties

    DEFF Research Database (Denmark)

    Subedi, Shaphal; Kawamoto, Ken; Karunarathna, Anurudda Kumara

    2013-01-01

    Time domain reflectometry (TDR) is used widely for measuring soil-water content. New TDR coil probe technology facilitates the development of small, nondestructive probes for simultaneous measurement of soil-water content (θ) and soil-water potential (ψ). In this study we developed mini tensiomet...... between measured soil-water retention curves (ψ > –100 cm H2O) by the new T-TDR coil probes and independent measurements by the hanging water column method....

  18. Soil properties and processes

    NARCIS (Netherlands)

    Hartemink, A.E.; McBratney, A.B.; White, R.E.

    2009-01-01

    This four-volume set, edited by leading experts in soil science, brings together in one collection a series of papers that have been fundamental to the development of soil science as a defined discipline. Tis volume 2 on Soil Properties and Processes covers: - Soil physics - Soil (bio)chemistry -

  19. Cokriging of Electromagnetic Induction Soil Electrical Conductivity Measurements and Soil Textural Properties to Demarcate Sub-field Management Zones for Precision Irrigation.

    Science.gov (United States)

    Ding, R.; Cruz, L.; Whitney, J.; Telenko, D.; Oware, E. K.

    2017-12-01

    There is the growing need for the development of efficient irrigation management practices due to increasing irrigation water scarcity as a result of growing population and changing climate. Soil texture primarily controls the water-holding capacity of soils, which determines the amount of irrigation water that will be available to the plant. However, while there are significant variabilities in the textural properties of the soil across a field, conventional irrigation practices ignore the underlying variability in the soil properties, resulting in over- or under-irrigation. Over-irrigation leaches plant nutrients beyond the root-zone leading to fertilizer, energy, and water wastages with dire environmental consequences. Under-irrigation, in contrast, causes water stress of the plant, thereby reducing plant quality and yield. The goal of this project is to leverage soil textural map of a field to create water management zones (MZs) to guide site-specific precision irrigation. There is increasing application of electromagnetic induction methods to rapidly and inexpensively map spatially continuous soil properties in terms of the apparent electrical conductivity (ECa) of the soil. ECa is a measure of the bulk soil properties, including soil texture, moisture, salinity, and cation exchange capacity, making an ECa map a pseudo-soil map. Data for the project were collected from a farm site at Eden, NY. The objective is to leverage high-resolution ECa map to predict spatially dense soil textural properties from limited measurements of soil texture. Thus, after performing ECa mapping, we conducted particle-size analysis of soil samples to determine the textural properties of soils at selected locations across the field. We cokriged the high-resolution ECa measurements with the sparse soil textural data to estimate a soil texture map for the field. We conducted irrigation experiments at selected locations to calibrate representative water-holding capacities of each

  20. GEOPHYSICAL PROPERTIES OF SOILS

    KAUST Repository

    Santamarina, Carlos

    2016-12-01

    Low energy perturbations used in geophysical methods provide insightful information about constant-fabric soil properties and their spatial variability. There are causal links between soil type, index properties, elastic wave velocity, electromagnetic wave parameters and thermal properties. Soil type relates to the stress-dependent S-wave velocity, thermal and electrical conductivity and permittivity. The small strain stiffness reflects the state of stress, the extent of diagenetic cementation and/or freezing. Pore fluid chemistry, fluid phase and changes in either fluid chemistry or phase manifest through electromagnetic measurements. The volumetric water content measured with electromagnetic techniques is the best predictor of porosity if the water saturation is 100%. Changes in water saturation alter the P-wave velocity when Srà100%, the S-wave velocity at intermediate saturations, and the thermal conductivity when the saturation is low Srà0%. Finally, tabulated values suffice to estimate heat capacity and latent heat for engineering design, however thermal conductivity requires measurements under proper field conditions.

  1. Test speed and other factors affecting the measurements of tree root properties used in soil reinforcement models

    NARCIS (Netherlands)

    Cofie, P.; Koolen, A.J.

    2001-01-01

    Measured values of the mechanical properties of tree roots are found to be affected by a number of factors. Shear properties of tree roots are found to be partly influenced by size of the testing equipment, level of soil compaction, deformation of the root material and estimated width of the shear

  2. Variability of standard artificial soils: Physico-chemical properties and phenanthrene desorption measured by means of supercritical fluid extraction

    International Nuclear Information System (INIS)

    Bielská, Lucie; Hovorková, Ivana; Komprdová, Klára; Hofman, Jakub

    2012-01-01

    The study is focused on artificial soil which is supposed to be a standardized “soil like” medium. We compared physico-chemical properties and extractability of Phenanthrene from 25 artificial soils prepared according to OECD standardized procedures at different laboratories. A substantial range of soil properties was found, also for parameters which should be standardized because they have an important influence on the bioavailability of pollutants (e.g. total organic carbon ranged from 1.4 to 6.1%). The extractability of Phe was measured by supercritical fluid extraction (SFE) at harsh and mild conditions. Highly variable Phe extractability from different soils (3–89%) was observed. The extractability was strongly related (R 2 = 0.87) to total organic carbon content, 0.1–2 mm particle size, and humic/fulvic acid ratio in the following multiple regression model: SFE (%) = 1.35 * sand (%) − 0.77 * TOC (%)2 + 0.27 * HA/FA. - Highlights: ► We compared properties and extractability of Phe from 25 different artificial soils. ► Substantial range of soil properties was found, also for important parameters. ► Phe extractability was measured by supercritical fluid extraction (SFE) at 2 modes. ► Phe extractability was highly variable from different soils (3–89%). ► Extractability was strongly related to TOC, 0.1–2 mm particles, and HA/FA. - Significant variability in physico-chemical properties exists between artificial soils prepared at different laboratories and affects behavior of contaminants in these soils.

  3. Measurement of Mars Analog Soil Dielectric Properties for Mars 2020 Radar Science Applications

    Science.gov (United States)

    Decrossas, E.; Bell, D. J.; Jin, C.; Steinfeld, D.; Batres, J.

    2017-12-01

    possible frequency bands. In their 2004 paper, Williams and Greely reported on measurements of the dielectric and attenuation properties of Mars soil analogs made in the band of 200 MHz to 1300 MHz. Their results apply directly to the Mars rover telecom links at 435 MHz and 915 MHz. This paper reports on dielectric measurements made on the same Mars soil analogs over the band of 7 GHz to 40 GHz.

  4. Predicting soil properties in the tropics

    NARCIS (Netherlands)

    Minasny, B.; Hartemink, A.E.

    2011-01-01

    It is practically impossible to measure soil properties continuously at each location across the globe. Therefore, it is necessary to have robust systems that can predict soil properties at a given location. That is needed in many tropical countries where the dearth of soil property measurements is

  5. Combining hyperspectral imagery and legacy measured soil profiles to map subsurface soil properties in a Mediterranean area (Cap-Bon, Tunisia)

    Science.gov (United States)

    Lagacherie, Philippe; Sneep, Anne-Ruth; Gomez, Cécile

    2013-04-01

    were calibrated over the set of legacy measured profiles and ii) the application of these functions over the study, using as input the hyperspectral-derived digital soil maps of surface soil properties and the images of landscape covariates. Error propagation in these two steps was addressed using a Monte Carlo approach for estimating the mapping uncertainties. The main results werea s follows: i) fairly satisfactory (R2 between 0.55 and 0.81) surface-subsurface functions were obtained for predicting soil properties at 15-30 cm and 30-60 cm whereas predictions at 60-100 cm were less accurate (R2 between 0.38 and 0.43) ii) linear models generally outperformed random-forest ones in developing surface-subsurface functions iii) Due to error propagations, the final maps of subsurface soil properties captured from 1/3 to 2/3 of the total variability with a significant decrease of performance with prediction depth, iv) these maps brought significant improvements from the existing soil maps of the region and showed soil patterns that were largely in accordance with the local pedological knowledge.

  6. Combination of soil classification and some selected soil properties ...

    African Journals Online (AJOL)

    The advantage in the combined use of soil classification and top soil analysis for explaining crop yield variation was examined. Soil properties and yields of maize (Zea mays L) on different soil types were measured on farmers' fields for 2 years. Yield prediction improved from 2 per cent at the Order and Association levels to ...

  7. An automated microinfiltrometer to measure small-scale soil water infiltration properties

    Directory of Open Access Journals (Sweden)

    Gordon Dennis C.

    2014-09-01

    Full Text Available We developed an automated miniature constant-head tension infiltrometer that measures very small infiltration rates at millimetre resolution with minimal demands on the operator. The infiltrometer is made of 2.9 mm internal radius glass tube, with an integrated bubbling tower to maintain constant negative head and a porous mesh tip to avoid air-entry. In the bubbling tower, bubble formation and release changes the electrical resistance between two electrodes at the air-inlet. Tests were conducted on repacked sieved sands, sandy loam soil and clay loam soil, packed to a soil bulk density ρd of 1200 kg m-3 or 1400 kg m-3 and tested either air-dried or at a water potential ψ of -50 kPa. The change in water volume in the infiltrometer had a linear relationship with the number of bubbles, allowing bubble rate to be converted to infiltration rate. Sorptivity measured with the infiltrometer was similar between replicates and showed expected differences from soil texture and ρd, varying from 0.15 ± 0.01 (s.e. mm s-1/2 for 1400 kg m-3 clay loam at ψ = -50 kPa to 0.65 ± 0.06 mm s-1/2 for 1200 kg m-3 air dry sandy loam soil. An array of infiltrometers is currently being developed so many measurements can be taken simultaneously.

  8. Soil/Rock Properties Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — Soil/Rock Properties LaboratoryLocation: Spokane SiteThe Soil/Rock Properties Laboratory is contained in the soils bay, a 4,700 sq. ft. facility that provides space...

  9. Predicting Soil-Air and Soil-Water Transport Properties During Soil Vapor Extraction

    DEFF Research Database (Denmark)

    Poulsen, Tjalfe

    Increased application of in-situ technology for control and removal of volatile organic compounds (VOC) in the subsurface has made the understanding of soil physical properties and their impact upon contaminant transport even more important. Knowledge of contaminant transport is important when...... properties of undisturbed soil from more easily measurable soil properties are developed. The importance of soil properties with respect to contaminant migration during remediation by soil vapor extraction (SVE) in the unsaturated zone was investigated using numerical simulations....

  10. Agricultural Soil Spectral Response and Properties Assessment: Effects of Measurement Protocol and Data Mining Technique

    Directory of Open Access Journals (Sweden)

    Asa Gholizadeh

    2017-10-01

    Full Text Available Soil spectroscopy has shown to be a fast, cost-effective, environmentally friendly, non-destructive, reproducible and repeatable analytical technique. Soil components, as well as types of instruments, protocols, sampling methods, sample preparation, spectral acquisition techniques and analytical algorithms have a combined influence on the final performance. Therefore, it is important to characterize these differences and to introduce an effective approach in order to minimize the technical factors that alter reflectance spectra and consequent prediction. To quantify this alteration, a joint project between Czech University of Life Sciences Prague (CULS and Tel-Aviv University (TAU was conducted to estimate Cox, pH-H2O, pH-KCl and selected forms of Fe and Mn. Two different soil spectral measurement protocols and two data mining techniques were used to examine seventy-eight soil samples from five agricultural areas in different parts of the Czech Republic. Spectral measurements at both laboratories were made using different ASD spectroradiometers. The CULS protocol was based on employing a contact probe (CP spectral measurement scheme, while the TAU protocol was carried out using a CP measurement method, accompanied with the internal soil standard (ISS procedure. Two spectral datasets, acquired from different protocols, were both analyzed using partial least square regression (PLSR technique as well as the PARACUDA II®, a new data mining engine for optimizing PLSR models. The results showed that spectra based on the CULS setup (non-ISS demonstrated significantly higher albedo intensity and reflectance values relative to the TAU setup with ISS. However, the majority of statistics using the TAU protocol was not noticeably better than the CULS spectra. The paper also highlighted that under both measurement protocols, the PARACUDA II® engine proved to be a powerful tool for providing better results than PLSR. Such initiative is not only a way to

  11. Soil conservation measures: exercises

    OpenAIRE

    Figueiredo, Tomás de; Fonseca, Felícia

    2009-01-01

    Exercises proposed under the topic of Soil Conservation Measures addresses to the design of structural measure, namely waterways in the context of a soil conservation plan. However, to get a better insight on the actual meaning of soil loss as a resource loss, a prior exercise is proposed to students. It concerns calculations of soil loss due to sheet (interrill) erosion and to gully erosion, and allows the perception through realistic number of the impact of these mechanism...

  12. Spatial Variability of Soil Physical Properties Obtained with Laboratory Methods and Their Relation to Field Electrical Resistivity Measurements

    Science.gov (United States)

    Dathe, A.; Nemes, A.; Bloem, E.; Patterson, M.; Gimenez, D.; Angyal, A.; Koestel, J. K.; Jarvis, N.

    2017-12-01

    Soil spatial heterogeneity plays a critical role for describing water and solute transport processes in the unsaturated zone. Although we have a sound understanding of the physical properties underlying this heterogeneity (like macropores causing preferential water flow), their quantification in a spatial context is still a challenge. To improve existing knowledge and modelling approaches we established a field experiment on an agriculturally used silty clay loam (Stagnosol) in SE Norway. Centimeter to decimeter scale heterogeneities were investigated in the field using electrical resistivity tomography (ERT) in a quasi-3D and a real 3D approach. More than 100 undisturbed soil samples were taken in the 2x1x1 m3plot investigated with 3D ERT to determine soil water retention, saturated and unsaturated hydraulic conductivities and bulk density in the laboratory. A subset of these samples was scanned at the computer tomography (CT) facility at the Swedish University of Agricultural Sciences in Uppsala, Sweden, with special emphasis on characterizing macroporosity. Results show that the ERT measurements captured the spatial distribution of bulk densities and reflected soil water contents. However, ERT could not resolve the large variation observed in saturated hydraulic conductivities from the soil samples. Saturated hydraulic conductivity was clearly related to the macroporosity visible in the CT scans obtained from the respective soil cores. Hydraulic conductivities close to saturation mainly changed with depths in the soil profile and therefore with bulk density. In conclusion, to quantify the spatial heterogeneity of saturated hydraulic conductivities scanning methods with a resolution smaller than the size of macropores have to be used. This is feasible only when the information obtained from for example CT scans of soil cores would be upscaled in a meaningful way.

  13. Simple measures of climate, soil properties and plant traits predict national-scale grassland soil carbon stocks

    NARCIS (Netherlands)

    Manning, P.; de Vries, F.T.; Tallowin, J.R.B.; Smith, R.; Mortimer, S.R.; Pilgrim, E.S.; Harrison, K.A.; Wright, D.G.; Quirk, H.; Benson, J.; Shipley, B.; Cornelissen, J.H.C.; Kattge, J.; Bönisch, G.; Wirth, C.; Bardgett, R.D.

    2015-01-01

    Soil carbon (C) storage is a key ecosystem service. Soil C stocks play a vital role in soil fertility and climate regulation, but the factors that control these stocks at regional and national scales are unknown, particularly when their composition and stability are considered. As a result, their

  14. Assessment the effect of homogenized soil on soil hydraulic properties and soil water transport

    Science.gov (United States)

    Mohawesh, O.; Janssen, M.; Maaitah, O.; Lennartz, B.

    2017-09-01

    Soil hydraulic properties play a crucial role in simulating water flow and contaminant transport. Soil hydraulic properties are commonly measured using homogenized soil samples. However, soil structure has a significant effect on the soil ability to retain and to conduct water, particularly in aggregated soils. In order to determine the effect of soil homogenization on soil hydraulic properties and soil water transport, undisturbed soil samples were carefully collected. Five different soil structures were identified: Angular-blocky, Crumble, Angular-blocky (different soil texture), Granular, and subangular-blocky. The soil hydraulic properties were determined for undisturbed and homogenized soil samples for each soil structure. The soil hydraulic properties were used to model soil water transport using HYDRUS-1D.The homogenized soil samples showed a significant increase in wide pores (wCP) and a decrease in narrow pores (nCP). The wCP increased by 95.6, 141.2, 391.6, 3.9, 261.3%, and nCP decreased by 69.5, 10.5, 33.8, 72.7, and 39.3% for homogenized soil samples compared to undisturbed soil samples. The soil water retention curves exhibited a significant decrease in water holding capacity for homogenized soil samples compared with the undisturbed soil samples. The homogenized soil samples showed also a decrease in soil hydraulic conductivity. The simulated results showed that water movement and distribution were affected by soil homogenizing. Moreover, soil homogenizing affected soil hydraulic properties and soil water transport. However, field studies are being needed to find the effect of these differences on water, chemical, and pollutant transport under several scenarios.

  15. Effects of environmental factors and soil properties on topographic variations of soil respiration

    OpenAIRE

    Tamai, K.

    2010-01-01

    Soil respiration rates were measured along different parts of a slope in (a) an evergreen forest with common brown forest soil and (b) a deciduous forest with immature soil. The effects of soil temperature, soil moisture and soil properties were estimated individually, and the magnitudes of these effects in the deciduous and evergreen forests were compared. In the evergreen forest with common brown forest soil, soil properties had the greatest effect on soil respiration rates, followed by soi...

  16. Soil hydraulic properties of Cuban soils

    International Nuclear Information System (INIS)

    Ruiz, M.E.; Medina, H.

    2004-01-01

    Because soil hydraulic properties are indispensable for determining soil water retention and soil water movement, their input for deterministic crop simulation models is essential. From these models is possible to access the effect of the weather changes, soil type or different irrigation schedules on crop yields. With these models, possibilities are provided to answer questions regarding virtual 'what happen if' experiments with a minimum of fieldwork. Nevertheless, determining soil hydraulic properties can be very difficult owing to unavailability of necessary equipment or the lack of personal with the proper knowledge for those tasks. These deficiencies are a real problem in developing countries, and even more so when there is not enough financial possibilities for research work. This paper briefly presents the way these properties have been accessed for Cuban soils, which methods have been used and the work now in progress. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Husson, Olivier, E-mail: Olivier.husson@cirad.fr [CIRAD/PERSYST/UPR 115 AIDA and AfricaRice Centre, 01 BP 2031 Cotonou (Benin); Husson, Benoit, E-mail: bhusson@ideeaquaculture.com [IDEEAQUACULTURE, Parc Euromédecine 2, 39 Rue Jean Giroux, 34080 Montpellier (France); Brunet, Alexandre, E-mail: brunet.alexandre@outlook.com [CIRAD/US 49 Analyse, Avenue Agropolis, TA B-49/01, 34398 Montpellier Cedex (France); Babre, Daniel, E-mail: Daniel.babre@cirad.fr [CIRAD/US 49 Analyse, Avenue Agropolis, TA B-49/01, 34398 Montpellier Cedex (France); Alary, Karine, E-mail: Karine.alary@cirad.fr [CIRAD/US 49 Analyse, Avenue Agropolis, TA B-49/01, 34398 Montpellier Cedex (France); Sarthou, Jean-Pierre, E-mail: sarthou@ensat.fr [ENSAT/INRA/INP UMR AGIR. BP 52627, Chemin de Borde Rouge, 31326 Castanet-Tolosan Cedex (France); Charpentier, Hubert, E-mail: Charpentier.hub@wanadoo.fr [La Boisfarderie, Brives 36100 (France); Durand, Michel, E-mail: earldeslacs@orange.fr [Le Cazals, Castanet 81 150 (France); Benada, Jaroslav, E-mail: benada@vukrom.cz [Agrotest fyto, Kromeriz Institute, Havlíckova 2787, 76701 Kromeriz (Czech Republic); Henry, Marc, E-mail: henry@unistra.fr [UMR CNRS/UdS 7140, Université de Strasbourg, Institut Le Bel, 4, rue Blaise Pascal, CS 90032, Strasbourg 67081 (France)

    2016-02-04

    The soil redox potential (Eh) can provide essential information to characterise soil conditions. In practice, however, numerous problems may arise regarding: (i) Eh determination in soils, especially aerobic soils, e.g. variations in the instrumentation and methodology for Eh measurement, high spatial and temporal Eh variability in soils, irreversibility of the redox reaction at the surface electrode, chemical disequilibrium; and (ii) measurement interpretation. This study aimed at developing a standardised method for redox potential measurement in soils, in order to use Eh as a soil quality indicator. This paper presents practical improvements in soil Eh measurement, especially regarding the control of electromagnetic perturbations, electrode choice and preparation, soil sample preparation (drying procedure) and soil:water extraction rate. The repeatability and reproducibility of the measurement method developed are highlighted. The use of Eh corrected at pH7, pe+pH or rH{sub 2}, which are equivalent notions, is proposed to facilitate interpretation of the results. The application of this Eh measurement method allows characterisation of soil conditions with sufficient repeatability, reproducibility and accuracy to demonstrate that conservation agriculture systems positively alter the protonic and electronic balance of soil as compared to conventional systems. - Highlights: • Electromagnetic fields can dramatically perturb soil Eh measurement. • Our method overcomes the main difficulties in soil Eh measurement. • Accurate and reproducible measurement of mean soil Eh are achieved. • Eh{sub pH7}, pe+pH and rH{sub 2} are equivalent notions characterising electron activity. • Agricultural practices alter soil protonic and electronic characteristics.

  18. Soil properties differently influence estimates of soil CO2 efflux from three chamber-based measurement systems

    Science.gov (United States)

    John R. Butnor; Kurt H. Johnsen; Chris A. Maier

    2005-01-01

    Soil C02 efflux is a major component of net ecosystem productivity (NEP) of forest systems. Combining data from multiple researchers for larger-scale modeling and assessment will only be valid if their methodologies provide directly comparable results. We conducted a series of laboratory and field tests to assess the presence and magnitude of...

  19. Comparative Study of Microbial Activity and Chemical Properties of Soil by Implementing Anti-erosion Measure Vertical Mulching with Organic Residues

    Directory of Open Access Journals (Sweden)

    Gergana Slavova Kuncheva

    2015-01-01

    Full Text Available Water soil erosion is a phenomenon in which soil particles are separated transported and translocated by the action of rain water. Removal of topsoil by water flow leads to a decrease of humus in the soil, deterioration of soil structure, compaction, and reduction of microbial activity.Developed and tested have been number of methods and technologies for soil protection from the effects of water erosion. Such technology is vertical mulching, and straw or compost applied as mulching material.This work is a study of the changes that occur in some soil chemical properties and soil microbiological activity, as a result in the implementation of anti-erosion measure vertical mulching with different mulching materials for growing corn and wheat grain on carbonate chernozem, on sloping agricultural lands.

  20. Efficiency evaluation of ground-penetrating radar by the results of measurement of dielectric properties of soils

    Energy Technology Data Exchange (ETDEWEB)

    Khakiev, Zelimkhan; Kislitsa, Konstantin; Yavna, Victor [Rostov State Transport University, Rostov-on-Don (Russian Federation)

    2012-12-15

    The work considers the depth evaluation of ground penetrating radar (GPR) surveys using the attenuation factor of electromagnetic radiation in a medium. A method of determining the attenuation factor of low-conductive non-magnetic soils is developed based on the results of direct measurements of permittivity and conductivity of soils in the range of typical frequencies of GPR. The method relies on measuring the shift and width of the resonance line after a soil sample is being placed into a tunable cavity resonator. The advantage of this method is the preservation of soil structure during the measurement.

  1. Monitoring the bio-stimulation of hydrocarbon-contaminated soils by measurements of soil electrical properties, and CO2 content and its 13C/12C isotopic signature

    Science.gov (United States)

    Noel, C.; Gourry, J.; Ignatiadis, I.; Colombano, S.; Dictor, M.; Guimbaud, C.; Chartier, M.; Dumestre, A.; Dehez, S.; Naudet, V.

    2013-12-01

    Hydrocarbon contaminated soils represent an environmental issue as it impacts on ecosystems and aquifers. Where significant subsurface heterogeneity exists, conventional intrusive investigations and groundwater sampling can be insufficient to obtain a robust monitoring of hydrocarbon contaminants, as the information they provide is restricted to vertical profiles at discrete locations, with no information between sampling points. In order to obtain wider information in space volume on subsurface modifications, complementary methods can be used like geophysics. Among geophysical methods, geoelectrical techniques such as electrical resistivity (ER) and induced polarization (IP) seem the more promising, especially to study the effects of biodegradation processes. Laboratory and field geoelectrical experiments to characterize soils contaminated by oil products have shown that mature hydrocarbon-contaminated soils are characterized by enhanced electrical conductivity although hydrocarbons are electrically resistive. This high bulk conductivity is due to bacterial impacts on geological media, resulting in changes in the chemical and physical properties and thus, to the geophysical properties of the ground. Moreover, microbial activity induced CO2 production and isotopic deviation of carbon. Indeed, produced CO2 will reflect the pollutant isotopic signature. Thus, the ratio δ13C(CO2) will come closer to δ13C(hydrocarbon). BIOPHY, project supported by the French National Research Agency (ANR), proposes to use electrical methods and gas analyses to develop an operational and non-destructive method for monitoring in situ biodegradation of hydrocarbons in order to optimize soil treatment. Demonstration field is located in the South of Paris (France), where liquid fuels (gasoline and diesel) leaked from some tanks in 1997. In order to stimulate biodegradation, a trench has been dug to supply oxygen to the water table and thus stimulate aerobic metabolic bioprocesses. ER and

  2. Thermal Properties of Soils

    Science.gov (United States)

    1981-12-01

    plagio - clase feldspar and pyroxene. The tine fraction may Surface area and its effects contain the clay "sheet" minerals (i.e. kaolinite. illite...Pyroxene, Kaoliniwe Unified By By Ortho. Plagio . amphibole, Basic clay min. Hematite Soil Soil soil petrogr. X.ray clase clase and Igneous and clay and no

  3. Evaluating sensitivity of unsaturated soil properties

    International Nuclear Information System (INIS)

    Abdel-Rahman, R.O.; El-Kamash, A.M.; Nagy, M.E.; Khalill, M.Y.

    2005-01-01

    The assessment of near surface disposal performance relay on numerical models of groundwater flow and contaminant transport. These models use the unsaturated soil properties as input parameters, which are subject to uncertainty due to measurements errors and the spatial variability in the subsurface environment. To ascertain how much the output of the model will depend on the unsaturated soil properties the parametric sensitivity analysis is used. In this paper, a parametric sensitivity analysis of the Van Genuchten moisture retention characteristic (VGMRC) model will be presented and conducted to evaluate the relative importance of the unsaturated soil properties under different pressure head values that represent various dry and wet conditions. (author)

  4. NASA Cold Land Processes Experiment (CLPX 2002/03): Field measurements of snowpack properties and soil moisture

    Science.gov (United States)

    Kelly Elder; Don Cline; Glen E. Liston; Richard Armstrong

    2009-01-01

    A field measurement program was undertaken as part NASA's Cold Land Processes Experiment (CLPX). Extensive snowpack and soil measurements were taken at field sites in Colorado over four study periods during the two study years (2002 and 2003). Measurements included snow depth, density, temperature, grain type and size, surface wetness, surface roughness, and...

  5. Hydraulic Property and Soil Textural Classification Measurements for Rainier Mesa, Nevada Test Site, Nevada

    Science.gov (United States)

    Ebel, Brian A.; Nimmo, John R.

    2010-01-01

    This report presents particle size analysis, field-saturated hydraulic conductivity measurements, and qualitative descriptions of surficial materials at selected locations at Rainier Mesa, Nevada. Measurements and sample collection were conducted in the Rainier Mesa area, including unconsolidated sediments on top of the mesa, an ephemeral wash channel near the mesa edge, and dry U12n tunnel pond sediments below the mesa. Particle size analysis used a combination of sieving and optical diffraction techniques. Field-saturated hydraulic conductivity measurements employed a single-ring infiltrometer with analytical formulas that correct for falling head and spreading outside the ring domain. These measurements may prove useful to current and future efforts at Rainier Mesa aimed at understanding infiltration and its effect on water fluxes and radionuclide transport in the unsaturated zone.

  6. Physical properties, structure, and shape of radioactive Cs from the Fukushima Daiichi Nuclear Power Plant accident derived from soil, bamboo and shiitake mushroom measurements.

    Science.gov (United States)

    Niimura, Nobuo; Kikuchi, Kenji; Tuyen, Ninh Duc; Komatsuzaki, Masakazu; Motohashi, Yoshinobu

    2015-01-01

    We conducted an elution experiment with contaminated soils using various aqueous reagent solutions and autoradiography measurements of contaminated bamboo shoots and shiitake mushrooms to determine the physical and chemical characteristics of radioactive Cs from the Fukushima Daiichi Nuclear Power Plant accident. Based on our study results and data in the literature, we conclude that the active Cs emitted by the accident fell to the ground as granular non-ionic materials. Therefore, they were not adsorbed or trapped by minerals in the soil, but instead physically adhere to the rough surfaces of the soil mineral particles. Granular Cs* can be transferred among media, such as soils and plants. The physical properties and dynamic behavior of the granular Cs* is expected to be helpful in considering methods for decontamination of soil, litter, and other media. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  7. Tillage Effects on Soil Properties & Respiration

    Science.gov (United States)

    Rusu, Teodor; Bogdan, Ileana; Moraru, Paula; Pop, Adrian; Duda, Bogdan; Cacovean, Horea; Coste, Camelia

    2015-04-01

    Soil tillage systems can be able to influence soil compaction, water dynamics, soil temperature and soil structural condition. These processes can be expressed as changes of soil microbiological activity, soil respiration and sustainability of agriculture. Objectives of this study were: 1) to assess the effects of tillage systems (Conventional System-CS, Minimum Tillage-MT, No-Tillage-NT) on soil compaction, soil temperature, soil moisture and soil respiration and 2) to establish the relationship that exists in changing soil properties. Three treatments were installed: CS-plough + disc; MT-paraplow + rotary grape; NT-direct sowing. The study was conducted on an Argic-Stagnic Faeoziom. The MT and NT applications reduce or completely eliminate the soil mobilization, due to this, soil is compacted in the first year of application. The degree of compaction is directly related to soil type and its state of degradation. The state of soil compaction diminished over time, tending toward a specific type of soil density. Soil moisture was higher in NT and MT at the time of sowing and in the early stages of vegetation and differences diminished over time. Moisture determinations showed statistically significant differences. The MT and NT applications reduced the thermal amplitude in the first 15 cm of soil depth and increased the soil temperature by 0.5-2.20C. The determinations confirm the effect of soil tillage system on soil respiration; the daily average was lower at NT (315-1914 mmoli m-2s-1) and followed by MT (318-2395 mmoli m-2s-1) and is higher in the CS (321-2480 mmol m-2s-1). Comparing with CS, all the two conservation tillage measures decreased soil respiration, with the best effects of no-tillage. An exceeding amount of CO2 produced in the soil and released into the atmosphere, resulting from aerobic processes of mineralization of organic matter (excessive loosening) is considered to be not only a way of increasing the CO2 in the atmosphere, but also a loss of

  8. Effects of environmental factors and soil properties on topographic variations of soil respiration

    Directory of Open Access Journals (Sweden)

    K. Tamai

    2010-03-01

    Full Text Available Soil respiration rates were measured along different parts of a slope in (a an evergreen forest with common brown forest soil and (b a deciduous forest with immature soil. The effects of soil temperature, soil moisture and soil properties were estimated individually, and the magnitudes of these effects in the deciduous and evergreen forests were compared. In the evergreen forest with common brown forest soil, soil properties had the greatest effect on soil respiration rates, followed by soil moisture and soil temperature. These results may be explained by the fact that different soil properties matured within different environments. It can be argued that the low soil respiration rates in the low parts of the slope in the evergreen forest resulted from soil properties and not from wet soil conditions. In the deciduous forest, soil respiration rates were more strongly affected by soil moisture and soil temperature than by soil properties. These effects were likely due to the immaturity of the forest soil.

  9. Postwildfire measurement of soil physical and hydraulic properties at selected sampling sites in the 2011 Las Conchas wildfire burn scar, Jemez Mountains, north-central New Mexico

    Science.gov (United States)

    Romero, Orlando C.; Ebel, Brian A.; Martin, Deborah A.; Buchan, Katie W.; Jornigan, Alanna D.

    2018-04-10

    The generation of runoff and the resultant flash flooding can be substantially larger following wildfire than for similar rainstorms that precede wildfire disturbance. Flash flooding after the 2011 Las Conchas Fire in New Mexico provided the motivation for this investigation to assess postwildfire effects on soil-hydraulic properties (SHPs) and soil-physical properties (SPPs) as a function of remotely sensed burn severity 4 years following the wildfire. A secondary purpose of this report is to illustrate a methodology to determine SHPs that analyzes infiltrometer data by using three different analysis methods. The SPPs and SHPs are measured as a function of remotely sensed burn severity by using the difference in the Normalized Burn Ratio (dNBR) metric for seven sites. The dNBR metric was used to guide field sample collection across a full spectrum of burn severities that covered the range of Monitoring Trends in Burn Severity (MTBS) and Burned Area Reflectance Classification (BARC) thematic classes from low to high severity. The SPPs (initial and saturated soil-water content, bulk density, soil-organic matter, and soil-particle size) and SHPs (field-saturated hydraulic conductivity and sorptivity) were measured under controlled laboratory conditions for soil cores collected in the field. The SHPs were estimated by using tension infiltrometer measurements and three different data analysis methods. These measurements showed large effects of burn severity, focused in the top1 centimeter (cm) of soil, on some SPPs (bulk density, soil organic matter, and particle sizes). The threshold of these bulk density and soil organic matter effects was between 300 and 400 dNBR, which corresponds to a MTBS thematic class between moderate and high burn severity and a BARC4 thematic class of high severity. Gravel content and the content of fines in the top 1 cm of soil had a higher threshold value between 450 and 500 dNBR. Lesser effects on SPPs were observed at depths of 1–3 cm

  10. Combined effects of climate, restoration measures and slope position in change in soil chemical properties and nutrient loss across lands affected by the Wenchuan Earthquake in China.

    Science.gov (United States)

    Lin, Yongming; Deng, Haojun; Du, Kun; Rafay, Loretta; Zhang, Guang-Shuai; Li, Jian; Chen, Can; Wu, Chengzhen; Lin, Han; Yu, Wei; Fan, Hailan; Ge, Yonggang

    2017-10-15

    The MS 8.0Wenchuan Earthquake in 2008 caused huge damage to land cover in the northwest of China's Sichuan province. In order to determine the nutrient loss and short term characteristics of change in soil chemical properties, we established an experiment with three treatments ('undestroyed', 'destroyed and treated', and 'destroyed and untreated'), two climate types (semi-arid hot climate and subtropical monsoon climate), and three slope positions (upslope, mid-slope, and bottom-slope) in 2011. Ten soil properties-including pH, organic carbon, total nitrogen, total phosphorus, total potassium, Ca 2+ , Mg 2+ , alkaline hydrolysable nitrogen, available phosphorus, and available potassium-were measured in surface soil samples in December 2014. Analyses were performed to compare the characteristics of 3-year change in soil chemical properties in two climate zones. This study revealed that soil organic carbon, total nitrogen, Ca 2+ content, alkaline hydrolysable nitrogen, available phosphorus, and available potassium were significantly higher in subtropical monsoon climate zones than in semi-arid hot climate zones. However, subtropical monsoon climate zones had a higher decrease in soil organic carbon, total nitrogen, total phosphorus, total potassium, and alkaline hydrolysable nitrogen in 'destroyed and untreated' sites than in semi-arid hot climate zones. Most soil chemical properties exhibited significant interactions, indicating that they may degrade or develop concomitantly. 'Destroyed and treated' sites in both climate types had lower C:P and N:P ratios than 'destroyed and untreated' sites. Principal component analysis (PCA) showed that the first, second, and third principal components explained 76.53% of the variation and might be interpreted as structural integrity, nutrient supply availability, and efficiency of soil; the difference of soil parent material; as well as weathering and leaching effects. Our study indicated that the characteristics of short term

  11. Soil physical properties affecting soil erosion in tropical soils

    International Nuclear Information System (INIS)

    Lobo Lujan, D.

    2004-01-01

    The total vegetated land area of the earth is about 11,500 hectare. Of this, about 12% is in South America. Of this, about 14% is degraded area. Water erosion, chemical degradation, wind erosion, and physical degradation have been reported as main types of degradation. In South America water erosion is a major process for soil degradation. Nevertheless, water erosion can be a consequence of degradation of the soil structure, especially the functional attributes of soil pores to transmit and retain water, and to facilitate root growth. Climate, soil and topographic characteristics determine runoff and erosion potential from agricultural lands. The main factors causing soil erosion can be divided into three groups: Energy factors: rainfall erosivity, runoff volume, wind strength, relief, slope angle, slope length; Protection factors: population density, plant cover, amenity value (pressure for use) and land management; and resistance factors: soil erodibility, infiltration capacity and soil management. The degree of soil erosion in a particular climatic zone, with particular soils, land use and socioeconomic conditions, will always result from a combination of the above mentioned factors. It is not easy to isolate a single factor. However, the soil physical properties that determine the soil erosion process, because the deterioration of soil physical properties is manifested through interrelated problems of surface sealing, crusting, soil compaction, poor drainage, impeded root growth, excessive runoff and accelerated erosion. When an unprotected soil surface is exposed to the direct impact of raindrops it can produce different responses: Production of smaller aggregates, dispersed particles, particles in suspension and translocation and deposition of particles. When this has occurred, the material is reorganized at the location into a surface seal. Aggregate breakdown under rainfall depends on soil strength and a certain threshold kinetic energy is needed to start

  12. Relationship between Topography and Some Soil Properties

    Directory of Open Access Journals (Sweden)

    M. J. Pajand

    2016-09-01

    Full Text Available Introduction: Topography is an important and effective property affecting the soil quality. Some researchers demonstrated that degree and aspect of land slope may influence the particle size distribution and gravel. Slope degree affects the surface and subsurface run-off, drainage, soil temperature, stability of soil aggregates and soil erosion. This research was carried out to determine the spatial variation of soil properties in different slope degrees of northern and southern slopes in Khorasan Razavei province, Iran. Material and Methods: This study was performed in Sanganeh research station (longitude 60o 15ʹ60ʺ and latitude 36o 41ʹ 36ʺ, of north-eastern, Khorasan Razavi province of Iran. In order to study the effects of topography on some soil physical and chemical properties, a topo-sequence with the same slope length, parent materials and cover crops was selected. 30 soil samples (0-30 cm depth were collected from different slopes of less than 5, 5-15, 15-30, 30-50 and more than 50 percent of both southern and northern aspects. In this study, the soil particle size distribution (texture was measured by hydrometer method, organic carbon and calcium carbonate were determined by wet oxidation and titration with HCl 6 M, respectively and soil structural stability index, aggregates mean weight diameter and particles fractal dimension were calculated by related equations. Finally, the studied soil properties of 5 slopes (less than 5, 5-15, 15-30, 30-50, and more than 50% and 2 aspects (north and south with 3 replicates were compared by nested experimental design and Tuky test in JMP statistical software. Results and Discussion: The maximum and minimum clay contents as well as fractal dimension and organic carbon contents were found in less than 5% and more than 50% of south slopes, respectively. Clay content and fractal dimension in north aspect were also significantly (P

  13. Mapping specific soil functions based on digital soil property maps

    Science.gov (United States)

    Pásztor, László; Fodor, Nándor; Farkas-Iványi, Kinga; Szabó, József; Bakacsi, Zsófia; Koós, Sándor

    2016-04-01

    Quantification of soil functions and services is a great challenge in itself even if the spatial relevance is supposed to be identified and regionalized. Proxies and indicators are widely used in ecosystem service mapping. Soil services could also be approximated by elementary soil features. One solution is the association of soil types with services as basic principle. Soil property maps however provide quantified spatial information, which could be utilized more versatilely for the spatial inference of soil functions and services. In the frame of the activities referred as "Digital, Optimized, Soil Related Maps and Information in Hungary" (DOSoReMI.hu) numerous soil property maps have been compiled so far with proper DSM techniques partly according to GSM.net specifications, partly by slightly or more strictly changing some of its predefined parameters (depth intervals, pixel size, property etc.). The elaborated maps have been further utilized, since even DOSoReMI.hu was intended to take steps toward the regionalization of higher level soil information (secondary properties, functions, services). In the meantime the recently started AGRAGIS project requested spatial soil related information in order to estimate agri-environmental related impacts of climate change and support the associated vulnerability assessment. One of the most vulnerable services of soils in the context of climate change is their provisioning service. In our work it was approximated by productivity, which was estimated by a sequential scenario based crop modelling. It took into consideration long term (50 years) time series of both measured and predicted climatic parameters as well as accounted for the potential differences in agricultural practice and crop production. The flexible parametrization and multiple results of modelling was then applied for the spatial assessment of sensitivity, vulnerability, exposure and adaptive capacity of soils in the context of the forecasted changes in

  14. Soil properties mapping with the DIGISOIL multi-sensor system

    Science.gov (United States)

    Grandjean, G.

    2012-04-01

    The multidisciplinary DIGISOIL project aimed to integrate and improve in situ and proximal measurement technologies for the assessment of soil properties and soil degradation indicators, going from the sensing technologies to their integration and their application in (digital) soil mapping (DSM). In order to assess and prevent soil degradation and to benefit from the different ecological, economical and historical functions of the soil in a sustainable way, high resolution and quantitative maps of soil properties are needed. The core objective of the project is to explore and exploit new capabilities of advanced geophysical technologies for answering this societal demand. To this aim, DIGISOIL addresses four issues covering technological, soil science and economic aspects: (i) the validation of geophysical (in situ, proximal and airborne) technologies and integrated pedo-geophysical inversion techniques (mechanistic data fusion) (ii) the relation between the geophysical parameters and the soil properties, (iii) the integration of the derived soil properties for mapping soil functions and soil threats, (iv) the pre-evaluation, standardisation and sub-industrialization of the proposed methodologies, including technical and economical studies related to the societal demand. With respect to these issues, the DIGISOIL project allows to develop, test and validate the most relevant geophysical technologies for mapping soil properties. The system was tested on different field tests, and validated the proposed technologies and solutions for each of the identified methods: geoelectric, GPR, EMI, seismics, magnetic and hyperspectral. After data acquisition systems, sensor geometry, and advanced data processing techniques have been developed and validated, we present now the solutions for going from geophysical data to soil properties maps. For two test sites, located respectively in Luxembourg (LU) and Mugello (IT) a set of soil properties maps have been produced. They give

  15. Bacterial community structure and soil properties of a subarctic tundra soil in Council, Alaska.

    Science.gov (United States)

    Kim, Hye Min; Jung, Ji Young; Yergeau, Etienne; Hwang, Chung Yeon; Hinzman, Larry; Nam, Sungjin; Hong, Soon Gyu; Kim, Ok-Sun; Chun, Jongsik; Lee, Yoo Kyung

    2014-08-01

    The subarctic region is highly responsive and vulnerable to climate change. Understanding the structure of subarctic soil microbial communities is essential for predicting the response of the subarctic soil environment to climate change. To determine the composition of the bacterial community and its relationship with soil properties, we investigated the bacterial community structure and properties of surface soil from the moist acidic tussock tundra in Council, Alaska. We collected 70 soil samples with 25-m intervals between sampling points from 0-10 cm to 10-20 cm depths. The bacterial community was analyzed by pyrosequencing of 16S rRNA genes, and the following soil properties were analyzed: soil moisture content (MC), pH, total carbon (TC), total nitrogen (TN), and inorganic nitrogen (NH4+ and NO3-). The community compositions of the two different depths showed that Alphaproteobacteria decreased with soil depth. Among the soil properties measured, soil pH was the most significant factor correlating with bacterial community in both upper and lower-layer soils. Bacterial community similarity based on jackknifed unweighted unifrac distance showed greater similarity across horizontal layers than through the vertical depth. This study showed that soil depth and pH were the most important soil properties determining bacterial community structure of the subarctic tundra soil in Council, Alaska. © 2014 The Authors. FEMS Microbiology Ecology published by John Wiley & Sons Ltd on behalf of the Federation of European Microbiological Societies.

  16. In-situ measurements of soil-water conductivity

    International Nuclear Information System (INIS)

    Murphy, C.E.

    1978-01-01

    Radionuclides and other environmentally important materials often move in association with water. In terrestrial ecosystems, the storage and movement of water in the soil is of prime importance to the hydrologic cycle of the ecosystem. The soil-water conductivity (the rate at which water moves through the soil) is a necessary input to models of soil-water movement. In situ techniques for measurement of soil-water conductivity have the advantage of averaging soil-water properties over larger areas than most laboratory methods. The in situ techniques also cause minimum disturbance of the soil under investigation. Results of measurements using a period of soil-water drainage after initial wetting indicate that soil-water conductivity and its variation with soil-water content can be determined with reasonable accuracy for the plot where the measurements were made. Further investigations are being carried out to look at variability between plots within a soil type

  17. Design and Fabrication of a Soil Moisture Meter Using Thermal Conductivity Properties of Soil

    Directory of Open Access Journals (Sweden)

    Subir DAS

    2011-09-01

    Full Text Available Study of soil for agricultural purposes is one of the main focuses of research since the beginning of civilization as food related requirements is closely linked with the soil. The study of soil has generated an interest among the researchers for very similar other reasons including understanding of soil water dynamics, evolution of agricultural water stress and validation of soil moisture modeling. In this present work design of a soil moisture measurement meter using thermal conductivity properties of soil has been proposed and experimental results are reported.

  18. Predicting saturated hydraulic conductivity using soil morphological properties

    Directory of Open Access Journals (Sweden)

    Gülay Karahan

    2016-01-01

    Full Text Available Many studies have been conducted to predict soil saturated hydraulic conductivity (Ks by parametric soil properties such as bulk density and particle-size distribution. Although soil morphological properties have a strong effect on Ks, studies predicting Ks by soil morphological properties such as type, size, and strength of soil structure; type, orientation and quantity of soil pores and roots and consistency are rare. This study aimed at evaluating soil morphological properties to predict Ks. Undisturbed soil samples (15 cm length and 8.0 cm id. were collected from topsoil (0-15 cm and subsoil (15-30 cm (120 samples with a tractor operated soil sampler at sixty randomly selected sampling sites on a paddy field and an adjecent grassland in Central Anatolia (Cankırı, Turkey. Synchronized disturbed soil samples were taken from the same sampling sites and sampling depths for basic soil analyses. Saturated hydraulic conductivity was measured on the soil columns using a constant-head permeameter. Following the Ks measurements, the upper part of soil columns were covered to prevent evaporation and colums were left to drain in the laboratory. When the water flow through the column was stopped, a subsample were taken for bulk density and then soil columns were disturbed for describing the soil morphological properties. In addition, soil texture, bulk density, pH, field capacity, wilting point, cation exchange capacity, specific surface area, aggregate stability, organic matter, and calcium carbonate were measured on the synchronized disturbed soil samples. The data were divided into training (80 data values and validation (40 data values sets. Measured values of Ks ranged from 0.0036 to 2.14 cmh-1 with a mean of 0.86 cmh-1. The Ks was predicted from the soil morphological and parametric properties by stepwise multiple linear regression analysis. Soil structure class, stickiness, pore-size, root-size, and pore-quantity contributed to the Ks prediction

  19. Hyperspectral remote sensing of postfire soil properties

    Science.gov (United States)

    Sarah A. Lewis; Peter R. Robichaud; William J. Elliot; Bruce E. Frazier; Joan Q. Wu

    2004-01-01

    Forest fires may induce changes in soil organic properties that often lead to water repellent conditions within the soil profile that decrease soil infiltration capacity. The remote detection of water repellent soils after forest fires would lead to quicker and more accurate assessment of erosion potential. An airborne hyperspectral image was acquired over the Hayman...

  20. Thermal remediation alters soil properties - a review.

    Science.gov (United States)

    O'Brien, Peter L; DeSutter, Thomas M; Casey, Francis X M; Khan, Eakalak; Wick, Abbey F

    2018-01-15

    Contaminated soils pose a risk to human and ecological health, and thermal remediation is an efficient and reliable way to reduce soil contaminant concentration in a range of situations. A primary benefit of thermal treatment is the speed at which remediation can occur, allowing the return of treated soils to a desired land use as quickly as possible. However, this treatment also alters many soil properties that affect the capacity of the soil to function. While extensive research addresses contaminant reduction, the range and magnitude of effects to soil properties have not been explored. Understanding the effects of thermal remediation on soil properties is vital to successful reclamation, as drastic effects may preclude certain post-treatment land uses. This review highlights thermal remediation studies that have quantified alterations to soil properties, and it supplements that information with laboratory heating studies to further elucidate the effects of thermal treatment of soil. Notably, both heating temperature and heating time affect i) soil organic matter; ii) soil texture and mineralogy; iii) soil pH; iv) plant available nutrients and heavy metals; v) soil biological communities; and iv) the ability of the soil to sustain vegetation. Broadly, increasing either temperature or time results in greater contaminant reduction efficiency, but it also causes more severe impacts to soil characteristics. Thus, project managers must balance the need for contaminant reduction with the deterioration of soil function for each specific remediation project. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Inversion of soil electrical conductivity data to estimate layered soil properties

    Science.gov (United States)

    CBulk apparent soil electrical conductivity (ECa) sensors respond to multiple soil properties, including clay content, water content, and salt content (i.e., salinity). They provide a single sensor value for an entire soil profile down to a sensor-dependent measurement depth, weighted by a nonlinear...

  2. The effect of intrinsic soil properties on soil quality assessments

    Directory of Open Access Journals (Sweden)

    Alessandro Samuel-Rosa

    2013-10-01

    Full Text Available The assessment of soil quality is based on indicators and indices derived from soil properties. However, intrinsic soil properties may interfere with other soil properties that vary under different land uses and are used to calculate the indices. The aim of this study was to assess the extent to which intrinsic soil properties (clay and iron oxide contents explain variable soil properties (sum of bases, potential acidity, organic carbon, total porosity, and bulk density under different land uses (native forest, no-tillage and conventional agriculture on small family farms in Southern Brazil. The results showed that the five properties evaluated can be included in soil quality assessments and are not influenced by the clay and iron oxide contents. It was concluded that for little weathered 1:1 and 2:1 phyllosilicate rich-soils, if the difference between the maximum and the minimum clay content under the different land uses is less than about 200 g kg-1 and the iron oxide content less than about 15 g kg-1, the physico-chemical soil properties in the surface layer are determined mostly by the land use.

  3. Ambient Vibrations Measurements and 1D Site Response Modelling as a Tool for Soil and Building Properties Investigation

    Directory of Open Access Journals (Sweden)

    Sebastiano Imposa

    2018-03-01

    Full Text Available The safety of historic buildings heritage is an important task that becomes more substantial when the buildings are directed to educational purposes. The present study aims at evaluating the dynamic features of the Benedettini complex, an historic monastery located in downtown Catania, which is at present the headquarters of the humanistic studies department of the University of Catania. Both the building’s complex response to a seismic input and the soil-to-structure interaction were investigated using ambient noise recordings. The results point out a multiple dynamic behaviour of the monastery structure that shows several oscillation modes, whereas the identification of a single natural frequency can be observed in some sites where the structure can more freely oscillate. This observation is also confirmed by the variability of computed damping values that appear linked to the different rigidity of the structure, as a function of the either the longitudinal or transversal orientation of the investigated structural elements. Moreover, the comparison between the building’s fundamental period and spectral ratios frequencies, which were obtained from free field ambient noise measurements located outside the monastery, outline the presence of potential resonance effects between the site and structure during a seismic event. Numerical modelling of the local seismic response confirms the obtained experimental site frequencies, setting into evidence that higher amplification factors are reached in the same frequency range characterizing the building.

  4. The TERRA-PNW Dataset: A New Source for Standardized Plant Trait, Forest Carbon Cycling, and Soil Properties Measurements from the Pacific Northwest US, 2000-2014.

    Science.gov (United States)

    Berner, L. T.; Law, B. E.

    2015-12-01

    Plant traits include physiological, morphological, and biogeochemical characteristics that in combination determine a species sensitivity to environmental conditions. Standardized, co-located, and geo-referenced species- and plot-level measurements are needed to address variation in species sensitivity to climate change impacts and for ecosystem process model development, parameterization and testing. We present a new database of plant trait, forest carbon cycling, and soil property measurements derived from multiple TERRA-PNW projects in the Pacific Northwest US, spanning 2000-2014. The database includes measurements from over 200 forest plots across Oregon and northern California, where the data were explicitly collected for scaling and modeling regional terrestrial carbon processes with models such as Biome-BGC and the Community Land Model. Some of the data are co-located at AmeriFlux sites in the region. The database currently contains leaf trait measurements (specific leaf area, leaf longevity, leaf carbon and nitrogen) from over 1,200 branch samples and 30 species, as well as plot-level biomass and productivity components, and soil carbon and nitrogen. Standardized protocols were used across projects, as summarized in an FAO protocols document. The database continues to expand and will include agricultural crops. The database will be hosted by the Oak Ridge National Laboratory (ORLN) Distributed Active Archive Center (DAAC). We hope that other regional databases will become publicly available to help enable Earth System Modeling to simulate species-level sensitivity to climate at regional to global scales.

  5. Photometric properties of Mars soils analogs

    Science.gov (United States)

    Pommerol, A.; Thomas, N.; Jost, B.; Beck, P.; Okubo, C.; McEwen, A.S.

    2013-01-01

    We have measured the bidirectional reflectance of analogs of dry, wet, and frozen Martian soils over a wide range of phase angles in the visible spectral range. All samples were produced from two geologic samples: the standard JSC Mars-1 soil simulant and Hawaiian basaltic sand. In a first step, experiments were conducted with the dry samples to investigate the effects of surface texture. Comparisons with results independently obtained by different teams with similar samples showed a satisfying reproducibility of the photometric measurements as well as a noticeable influence of surface textures resulting from different sample preparation procedures. In a second step, water was introduced to produce wet and frozen samples and their photometry investigated. Optical microscope images of the samples provided information about their microtexture. Liquid water, even in relatively low amount, resulted in the disappearance of the backscattering peak and the appearance of a forward-scattering peak whose intensity increases with the amount of water. Specular reflections only appeared when water was present in an amount large enough to allow water to form a film at the surface of the sample. Icy samples showed a wide variability of photometric properties depending on the physical properties of the water ice. We discuss the implications of these measurements in terms of the expected photometric behavior of the Martian surface, from equatorial to circum-polar regions. In particular, we propose some simple photometric criteria to improve the identification of wet and/or icy soils from multiple observations under different geometries.

  6. Soil physicochemical properties and their significance for ...

    African Journals Online (AJOL)

    Soil physicochemical properties and their significance for sustainable sugarcane production in Kesem Allaideghe plains irrigation project area, Eastern Ethiopia. ... In order to improve soil structure and water availability, addition of gypsum, plant residues and organic matter are recommended. Keywords: Soil survey ...

  7. The moisture response of soil heterotrophic respiration: interaction with soil properties

    DEFF Research Database (Denmark)

    Moyano, F E; Vasilyeva, N; Bouckaert, L

    2012-01-01

    the heterotrophic respiration response to moisture have limited empirical support and introduce an uncertainty of at least 4% in global soil carbon stock predictions by 2100. The necessity of improving the representation of this relationship in models has been highlighted in recent studies. Here we present a data......Soil moisture is of primary importance for predicting the evolution of soil carbon stocks and fluxes, both because it strongly controls organic matter decomposition and because it is predicted to change at global scales in the following decades. However, the soil functions used to model......-driven analysis of soil moisture-respiration relations based on 90 soils. With the use of linear models we show how the relationship between soil heterotrophic respiration and different measures of soil moisture is consistently affected by soil properties. The empirical models derived include main effects...

  8. Hygrothermal Material Properties for Soils in Building Science

    Energy Technology Data Exchange (ETDEWEB)

    Kehrer, Manfred [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Pallin, Simon B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-01-01

    Hygrothermal performance of soils coupled to buildings is complicated because of the dearth of information on soil properties. However they are important when numerical simulation of coupled heat and moisture transport for below-grade building components are performed as their temperature and moisture content has an influence on the durability of the below-grade building component. Soils can be classified by soil texture. According to the Unified Soil Classification System (USCA), 12 different soils can be defined on the basis of three soil components: clay, sand, and silt. This study shows how existing material properties for typical American soils can be transferred and used for the calculation of the coupled heat and moisture transport of building components in contact with soil. Furthermore a thermal validation with field measurements under known boundary conditions is part of this study, too. Field measurements for soil temperature and moisture content for two specified soils are carried out right now under known boundary conditions. As these field measurements are not finished yet, the full hygrothermal validation is still missing

  9. Physical properties of organic soils. Chapter 5.

    Science.gov (United States)

    Elon S. Verry; Don H. Boelter; Juhani Paivanen; Dale S. Nichols; Tom Malterer; Avi Gafni

    2011-01-01

    Compared with research on mineral soils, the study of the physical properties of organic soils in the United States is relatively new. A comprehensive series of studies on peat physical properties were conducted by Don Boelter (1959-1975), first at the Marcell Experimental Forest (MEF) and later throughout the northern Lakes States to investigate how to express bulk...

  10. Soil properties from seismic intrinsic dispersion

    NARCIS (Netherlands)

    Zhubayev, A.S.

    2014-01-01

    Theoretical and experimental studies in the past have shown the sensitivity of seismic waves to soil/rock properties, such as composition, porosity, pore fluid, and permeability. However, quantitative characterization of these properties has remained challenging. In case of unconsolidated soils, the

  11. Magnetic properties of alluvial soils polluted with heavy metals

    Science.gov (United States)

    Dlouha, S.; Petrovsky, E.; Boruvka, L.; Kapicka, A.; Grison, H.

    2012-04-01

    Magnetic properties of soils, reflecting mineralogy, concentration and grain-size distribution of Fe-oxides, proved to be useful tool in assessing the soil properties in terms of various environmental conditions. Measurement of soil magnetic properties presents a convenient method to investigate the natural environmental changes in soils as well as the anthropogenic pollution of soils with several risk elements. The effect of fluvial pollution with Cd, Cu, Pb and Zn on magnetic soil properties was studied on highly contaminated alluvial soils from the mining/smelting district (Příbram; CZ) using a combination of magnetic and geochemical methods. The basic soil characteristics, the content of heavy metals, oxalate, and dithionite extractable iron were determined in selected soil samples. Soil profiles were sampled using HUMAX soil corer and the magnetic susceptibility was measured in situ, further detailed magnetic analyses of selected distinct layers were carried out. Two types of variations of magnetic properties in soil profiles were observed corresponding to indentified soil types (Fluvisols, and Gleyic Fluvisols). Significantly higher values of topsoil magnetic susceptibility compared to underlying soil are accompanied with high concentration of heavy metals. Sequential extraction analysis proved the binding of Pb, Zn and Cd in Fe and Mn oxides. Concentration and size-dependent parameters (anhysteretic and isothermal magnetization) were measured on bulk samples in terms of assessing the origin of magnetic components. The results enabled to distinguish clearly topsoil layers enhanced with heavy metals from subsoil samples. The dominance of particles with pseudo-single domain behavior in topsoil and paramagnetic/antiferromagnetic contribution in subsoil were observed. These measurements were verified with room temperature hysteresis measurement carried out on bulk samples and magnetic extracts. Thermomagnetic analysis of magnetic susceptibility measured on

  12. Physical and Chemical Properties of Soils under Contrasting Land ...

    African Journals Online (AJOL)

    Physical and Chemical Properties of Soils under Contrasting Land Use ... the aim of understanding the response of the soil to different management practices over time. ... The soil chemical properties studied were soil pH, organic carbon, total ...

  13. The relationship between ancient trees health and soil properties

    African Journals Online (AJOL)

    Yomi

    2011-12-07

    Dec 7, 2011 ... Key words: Ancient trees health, soil properties, Beijing. INTRODUCTION ... growth. Soil chemical properties play an invaluable role ..... situation on soil nutrients and fertilization in eucalyptus plantations in. GuangXi. Soil and ...

  14. Soil Properties Database of Spanish Soils Volume III.- Extremadura

    International Nuclear Information System (INIS)

    Trueba, C; Millan, R.; Schmid, T.; Roquero, C; Magister, M.

    1998-01-01

    The soil vulnerability determines the sensitivity of the soil after an accidental radioactive contamination due to Cs-13 7 and Sr-90. The Departamento de Impacto Ambiental de la Energia of CIEMAT is carrying out an assessment of the radiological vulnerability of the different Spanish soils found on the Iberian Peninsula. This requires the knowledge of the soil properties for the various types of existing soils. In order to achieve this aim, a bibliographical compilation of soil profiles has been made to characterize the different soil types and create a database of their properties. Depending on the year of publication and the type of documentary source, the information compiled from the available bibliography is very heterogeneous. Therefore, an important effort has been made to normalize and process the information prior to its incorporation to the database. This volume presents the criteria applied to normalized and process the data as well as the soil properties of the various soil types belonging to the Comunidad Autonoma de Extremadura. (Author) 50 refs

  15. Soil Properties Database of Spanish Soils. Volume V.- Madrid

    International Nuclear Information System (INIS)

    Trueba, C.; Millan, R.; Schmid, T.; Roquero, C.; Magister, M.

    1998-01-01

    The soil vulnerability determines the sensitivity of the soil after an accidental radioactive contamination due to Cs-137 and Sr-90. The Departamento de Impacto Ambiental de la Energia of CIEMAT is carrying out an assessment of the radiological vulnerability of the different Spanish soils found on the Iberian Peninsula. This requires the knowledge of the soil properties for the various types of existing soils. In order to achieve this aim, a bibliographical compilation of soil profiles has been made to characterize the different soil types and create a database of their properties. Depending on the year of publication and the type of documentary source, the information compiled from the available bibliography is very heterogeneous. Therefore, an important effort has been made to normalize and process the information prior to its incorporation to the database. This volume presents the criteria applied to normalize and process the data as well as the soil properties of the various soil types belonging to the Comunidad Autonoma de Madrid. (Author) 39 refs

  16. Soil Properties Database of Spanish Soils. Volume XV.- Aragon

    International Nuclear Information System (INIS)

    Trueba, C; Millan, R.; Schmid, T.; Lago, C.; Roquero, C; Magister, M.

    1999-01-01

    The soil vulnerability determines the sensitivity of the soil after an accidental radioactive contamination due to Cs-137 and Sr-90. The Departamento de Impacto Ambiental de la Energia of CIEMAT is carrying out an assessment of the radiological vulnerability of the different Spanish soils found on the Iberian Peninsula. This requires the knowledge of the soil properties for the various types of existing soils. In order to achieve this aim, a bibliographical compilation of soil profiles has been made to characterize the different soil types and create a database of their properties. Depending on the year of publication and the type of documentary source, the information compiled from the available bibliography is very heterogeneous. Therefore, an important effort has been made to normalize and process the information prior to its incorporation to the database. This volume presents the criteria applied to normalize and process the data as well as the soil properties of the various soil types belonging to the Comunidad Autonoma of Aragon. (Author) 47 refs

  17. Soil Properties Database of Spanish Soils Volume I.-Galicia

    International Nuclear Information System (INIS)

    Trueba, C.; Millan, R.; Schmid, T.; Roquero, C.; Magister, M.

    1998-01-01

    The soil vulnerability determines the sensitivity of the soil after an accidental radioactive contamination due to Cs-13 7 and Sr-90. The Department de Impacto Ambiental de la Energia of CIEMAT is carrying out an assessment of the radiological vulnerability of the different Spanish soils found on the Iberian Peninsula. This requires the knowledge of the soil properties for the various types of existing soils. In order to achieve this aim. a bibliographical compilation of soil profiles has been made to characterize the different soil types and create a database of their properties. Depending on the year of publication and the type of documentary)' source, the information compiled from the available bibliography is very heterogeneous. Therefore, an important effort has been made to normalize and process the information prior to its incorporation to the database. This volume presents the criteria applied to normalize and process the data as well as the soil properties of the various soil types belonging to the Comunidad Autonoma de Galicia

  18. Soil Properties Database of Spanish Soils. Volume XIV.- Cataluna

    International Nuclear Information System (INIS)

    Trueba, C; Millan, R.; Schmid, T.; Lago, C.; Roquero, C; Magister, M.

    1999-01-01

    The soil vulnerability determines the sensitivity of the soil after an accidental radioactive contamination due to Cs-137 and Sr-90. The Departamento de Impacto Ambiental de la Energia of CIEMAT is carrying out an assessment of the radiological vulnerability of the different Spanish soils found on the Iberian Peninsula. This requires the knowledge of the soil properties for the various types of existing soils. In order to achieve this aim, a bibliographical compilation of soil profiles has been made to characterize the different soil types and create a database of their properties. Depending on the year of publication and the type of documentary source, the information compiled from the available bibliography is very heterogeneous. Therefore, an important effort has been made to normalize and process the information prior to its incorporation to the database. This volume presents the criteria applied to normalize and process the data as well as the soil properties of the various soil types belonging to the Comunidad Autonoma of Cataluna. (Author) 57 refs

  19. Hygrothermal Simulation of Foundations: Part 1 - Soil Material Properties

    Energy Technology Data Exchange (ETDEWEB)

    Kehrer, Manfred [ORNL; Pallin, Simon B [ORNL

    2012-10-01

    The hygrothermal performance of soils coupled to buildings is a complicated process. A computational approach for heat transfer through the ground has been well defined (EN ISO 13370:2007, 2007), and simplified methods have been developed (Staszczuk, Radon, and Holm 2010). However, these approaches generally ignore the transfer of soil moisture, which is not negligible (Janssen, Carmeliet, and Hens 2004). This study is divided into several parts. The intention of the first part is to gather, comprehend and adapt soil properties from Soil Science. The obtained information must be applicable to related tasks in Building Science and validated with hygrothermal calculation tools. Future parts of this study will focus on the validation aspect of the soil properties to be implemented. Basic changes in the software code may be requested at this time. Different types of basement construction will be created with a hygrothermal calculation tool, WUFI. Simulations from WUFI will be compared with existing or ongoing measurements. The intentions of the first part of this study have been fulfilled. The soil properties of interest in Building Science have been defined for 12 different soil textures. These properties will serve as input parameters when performing hygrothermal calculations of building constructions coupled to soil materials. The reliability of the soil parameters will be further evaluated with measurements in Part 2.

  20. Impacts of land leveling on lowland soil physical properties

    Directory of Open Access Journals (Sweden)

    José Maria Barbat Parfitt

    2014-02-01

    Full Text Available The practice of land leveling alters the soil surface to create a uniform slope to improve land conditions for the application of all agricultural practices. The aims of this study were to evaluate the impacts of land leveling through the magnitudes, variances and spatial distributions of selected soil physical properties of a lowland area in the State of Rio Grande do Sul, Brazil; the relationships between the magnitude of cuts and/or fills and soil physical properties after the leveling process; and evaluation of the effect of leveling on the spatial distribution of the top of the B horizon in relation to the soil surface. In the 0-0.20 m layer, a 100-point geo-referenced grid covering two taxonomic soil classes was used in assessment of the following soil properties: soil particle density (Pd and bulk density (Bd; total porosity (Tp, macroporosity (Macro and microporosity (Micro; available water capacity (AWC; sand, silt, clay, and dispersed clay in water (Disp clay contents; electrical conductivity (EC; and weighted average diameter of aggregates (WAD. Soil depth to the top of the B horizon was also measured before leveling. The overall effect of leveling on selected soil physical properties was evaluated by paired "t" tests. The effect on the variability of each property was evaluated through the homogeneity of variance test. The thematic maps constructed by kriging or by the inverse of the square of the distances were visually analyzed to evaluate the effect of leveling on the spatial distribution of the properties and of the top of the B horizon in relation to the soil surface. Linear regression models were fitted with the aim of evaluating the relationship between soil properties and the magnitude of cuts and fills. Leveling altered the mean value of several soil properties and the agronomic effect was negative. The mean values of Bd and Disp clay increased and Tp, Macro and Micro, WAD, AWC and EC decreased. Spatial distributions of all

  1. Effects of soil properties on copper toxicity to earthworm Eisenia fetida in 15 Chinese soils.

    Science.gov (United States)

    Duan, Xiongwei; Xu, Meng; Zhou, Youya; Yan, Zengguang; Du, Yanli; Zhang, Lu; Zhang, Chaoyan; Bai, Liping; Nie, Jing; Chen, Guikui; Li, Fasheng

    2016-02-01

    The bioavailability and toxicity of metals in soil are influenced by a variety of soil properties, and this principle should be recognized in establishing soil environmental quality criteria. In the present study, the uptake and toxicity of Cu to the earthworm Eisenia fetida in 15 Chinese soils with various soil properties were investigated, and regression models for predicting Cu toxicity across soils were developed. The results showed that earthworm survival and body weight change were less sensitive to Cu than earthworm cocoon production. The soil Cu-based median effective concentrations (EC50s) for earthworm cocoon production varied from 27.7 to 383.7 mg kg(-1) among 15 Chinese soils, representing approximately 14-fold variation. Soil cation exchange capacity and organic carbon content were identified as key factors controlling Cu toxicity to earthworm cocoon production, and simple and multiple regression models were developed for predicting Cu toxicity across soils. Tissue Cu-based EC50s for earthworm cocoon production were also calculated and varied from 15.5 to 62.5 mg kg(-1) (4-fold variation). Compared to the soil Cu-based EC50s for cocoon production, the tissue Cu-based EC50s had less variation among soils, indicating that metals in tissue were more relevant to toxicity than metals in soil and hence represented better measurements of bioavailability. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Synthesis of soil-hydraulic properties and infiltration timescales in wildfire-affected soils

    Science.gov (United States)

    Ebel, Brian A.; Moody, John A.

    2017-01-01

    We collected soil-hydraulic property data from the literature for wildfire-affected soils, ash, and unburned soils. These data were used to calculate metrics and timescales of hydrologic response related to infiltration and surface runoff generation. Sorptivity (S) and wetting front potential (Ψf) were significantly different (lower) in burned soils compared with unburned soils, whereas field-saturated hydraulic conductivity (Kfs) was not significantly different. The magnitude and duration of the influence of capillarity during infiltration was greatly reduced in burned soils, causing faster ponding times in response to rainfall. Ash had large values of S and Kfs but moderate values of Ψf, compared with unburned and burned soils, indicating ash has long ponding times in response to rainfall. The ratio of S2/Kfs was nearly constant (~100 mm) for unburned soils but more variable in burned soils, suggesting that unburned soils have a balance between gravity and capillarity contributions to infiltration that may depend on soil organic matter, whereas in burned soils the gravity contribution to infiltration is greater. Changes in S and Kfs in burned soils act synergistically to reduce infiltration and accelerate and amplify surface runoff generation. Synthesis of these findings identifies three key areas for future research. First, short timescales of capillary influences on infiltration indicate the need for better measurements of infiltration at times less than 1 min to accurately characterize S in burned soils. Second, using parameter values, such as Ψf, from unburned areas could produce substantial errors in hydrologic modeling when used without adjustment for wildfire effects, causing parameter compensation and resulting underestimation of Kfs. Third, more thorough measurement campaigns that capture soil-structural changes, organic matter impacts, quantitative water repellency trends, and soil-water content along with soil-hydraulic properties could drive the

  3. Effect of different soil washing solutions on bioavailability of residual arsenic in soils and soil properties.

    Science.gov (United States)

    Im, Jinwoo; Yang, Kyung; Jho, Eun Hea; Nam, Kyoungphile

    2015-11-01

    The effect of soil washing used for arsenic (As)-contaminated soil remediation on soil properties and bioavailability of residual As in soil is receiving increasing attention due to increasing interest in conserving soil qualities after remediation. This study investigates the effect of different washing solutions on bioavailability of residual As in soils and soil properties after soil washing. Regardless of washing solutions, the sequential extraction revealed that the residual As concentrations and the amount of readily labile As in soils were reduced after soil washing. However, the bioassay tests showed that the washed soils exhibited ecotoxicological effects - lower seed germination, shoot growth, and enzyme activities - and this could largely be attributed to the acidic pH and/or excessive nutrient contents of the washed soils depending on washing solutions. Overall, this study showed that treated soils having lower levels of contaminants could still exhibit toxic effects due to changes in soil properties, which highly depended on washing solutions. This study also emphasizes that data on the As concentrations, the soil properties, and the ecotoxicological effects are necessary to properly manage the washed soils for reuses. The results of this study can, thus, be utilized to select proper post-treatment techniques for the washed soils. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Pedotransfer functions estimating soil hydraulic properties using different soil parameters

    DEFF Research Database (Denmark)

    Børgesen, Christen Duus; Iversen, Bo Vangsø; Jacobsen, Ole Hørbye

    2008-01-01

    Estimates of soil hydraulic properties using pedotransfer functions (PTF) are useful in many studies such as hydrochemical modelling and soil mapping. The objective of this study was to calibrate and test parametric PTFs that predict soil water retention and unsaturated hydraulic conductivity...... parameters. The PTFs are based on neural networks and the Bootstrap method using different sets of predictors and predict the van Genuchten/Mualem parameters. A Danish soil data set (152 horizons) dominated by sandy and sandy loamy soils was used in the development of PTFs to predict the Mualem hydraulic...... conductivity parameters. A larger data set (1618 horizons) with a broader textural range was used in the development of PTFs to predict the van Genuchten parameters. The PTFs using either three or seven textural classes combined with soil organic mater and bulk density gave the most reliable predictions...

  5. Microwave remote sensing of soil moisture for estimation of profile soil property

    International Nuclear Information System (INIS)

    Mattikalli, N.M.; Engman, E.T.; Ahuja, L.R.; Jackson, T.J.

    1998-01-01

    Multi-temporal microwave remotely-sensed soil moisture has been utilized for the estimation of profile soil property, viz. the soil hydraulic conductivity. Passive microwave remote sensing was employed to collect daily soil moisture data across the Little Washita watershed, Oklahoma, during 10-18 June 1992. The ESTAR (Electronically Steered Thin Array Radiometer) instrument operating at L -band was flown on a NASA C-130 aircraft. Brightness temperature (TB) data collected at a ground resolution of 200m were employed to derive spatial distribution of surface soil moisture. Analysis of spatial and temporal soil moisture information in conjunction with soils data revealed a direct relation between changes in soil moisture and soil texture. A geographical information system (GIS) based analysis suggested that 2-days initial drainage of soil, measured from remote sensing, was related to an important soil hydraulic property viz. the saturated hydraulic conductivity (Ksat). A hydrologic modelling methodology was developed for estimation of Ksat of surface and sub-surface soil layers. Specifically, soil hydraulic parameters were optimized to obtain a good match between model estimated and field measured soil moisture profiles. Relations between 2-days soil moisture change and Ksat of 0-5 cm, 0-30 cm and 0-60cm depths yielded correla tions of 0.78, 0.82 and 0.71, respectively. These results are comparable to the findings of previous studies involving laboratory-controlled experiments and numerical simulations, and support their extension to the field conditions of the Little Washita watershed. These findings have potential applications of microwave remote sensing to obtain 2-days of soil moisture and then to quickly estimate the spatial distribution of Ksat over large areas. (author)

  6. Thermal Properties Measurement Report

    Energy Technology Data Exchange (ETDEWEB)

    Carmack, Jon [Idaho National Lab. (INL), Idaho Falls, ID (United States); Braase, Lori [Idaho National Lab. (INL), Idaho Falls, ID (United States); Papesch, Cynthia [Idaho National Lab. (INL), Idaho Falls, ID (United States); Hurley, David [Idaho National Lab. (INL), Idaho Falls, ID (United States); Tonks, Michael [Idaho National Lab. (INL), Idaho Falls, ID (United States); Zhang, Yongfeng [Idaho National Lab. (INL), Idaho Falls, ID (United States); Gofryk, Krzysztof [Idaho National Lab. (INL), Idaho Falls, ID (United States); Harp, Jason [Idaho National Lab. (INL), Idaho Falls, ID (United States); Fielding, Randy [Idaho National Lab. (INL), Idaho Falls, ID (United States); Knight, Collin [Idaho National Lab. (INL), Idaho Falls, ID (United States); Meyer, Mitch [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-08-01

    The Thermal Properties Measurement Report summarizes the research, development, installation, and initial use of significant experimental thermal property characterization capabilities at the INL in FY 2015. These new capabilities were used to characterize a U3Si2 (candidate Accident Tolerant) fuel sample fabricated at the INL. The ability to perform measurements at various length scales is important and provides additional data that is not currently in the literature. However, the real value of the data will be in accomplishing a phenomenological understanding of the thermal conductivity in fuels and the ties to predictive modeling. Thus, the MARMOT advanced modeling and simulation capability was utilized to illustrate how the microstructural data can be modeled and compared with bulk characterization data. A scientific method was established for thermal property measurement capability on irradiated nuclear fuel samples, which will be installed in the Irradiated Material Characterization Laboratory (IMCL).

  7. Interpreting, measuring, and modeling soil respiration

    Science.gov (United States)

    Michael G. Ryan; Beverly E. Law

    2005-01-01

    This paper reviews the role of soil respiration in determining ecosystem carbon balance, and the conceptual basis for measuring and modeling soil respiration. We developed it to provide background and context for this special issue on soil respiration and to synthesize the presentations and discussions at the workshop. Soil respiration is the largest component of...

  8. Soil properties related to 60Co bioavailability in tropical soils

    International Nuclear Information System (INIS)

    Bartoly, Flavia; Wasserman, Maria Angelica; Rochedo, Elaine Ruas Rodriguez; Viana, Aline Gonzalez; Souza, Rodrigo Camara; Oliveira, Giselle Rodrigues; Reis, Wagner Goncalves Soares; Perez, Daniel Vidal

    2005-01-01

    This work presents the results of field experiments to obtain soil to plants Transfer factor (TF) for 60 Co in reference plants cultivated in Ferralsol, Acrisol and Nitisol. These soils represent the majority of Brazilian agricultural area. Values of TF varied from 0.001 to 0.05 for corn and from 0.001 to 0.81 for cabbage. Results of 60 Co TF were discussed in relation to the physical and chemical properties of the soils and 60 Co geochemical partition. The sequential chemical extraction showed that more than 40% of the 60 Co present in the soils are associated to manganese oxides. These results will provide regional values for parameters used in the environmental radiological modeling aiming to optimize the planning of emergency interventions or the waste management related to tropical soils. (author)

  9. Geotechnical properties of Egyptian collapsible soils

    Directory of Open Access Journals (Sweden)

    Khaled E. Gaaver

    2012-09-01

    Full Text Available The risk of constructing structures on collapsible soils presents significant challenges to geotechnical engineers due to sudden reduction in volume upon wetting. Identifying collapsible soils when encountered in the field and taking the needed precautions should substantially reduce the risk of such problems usually reported in buildings and highways. Collapsible soils are those unsaturated soils that can withstand relatively high pressure without showing significant change in volume, however upon wetting; they are susceptible to a large and sudden reduction in volume. Collapsible soils cover significant areas around the world. In Egypt, collapsible soils were observed within the northern portion of the western desert including Borg El-Arab region, and around the city of Cairo in Six-of-October plateau, and Tenth-of-Ramadan city. Settlements associated with development on untreated collapsible soils usually lead to expensive repairs. One method for treating collapsible soils is to densify their structure by compaction. The ongoing study presents the effect of compaction on the geotechnical properties of the collapsible soils. Undisturbed block samples were recovered from test pits at four sites in Borg El-Arab district, located at about 20 km west of the city of Alexandria, Egypt. The samples were tested in both unsoaked and soaked conditions. Influence of water inundation on the geotechnical properties of collapsible soils was demonstrated. A comparative study between natural undisturbed and compacted samples of collapsible soils was performed. An attempt was made to relate the collapse potential to the initial moisture content. An empirical correlation between California Bearing Ratio of the compacted collapsible soils and liquid limit was adopted. The presented simple relationships should enable the geotechnical engineers to estimate the complex parameters of collapsible soils using simple laboratory tests with a reasonable accuracy.

  10. Modeling multidomain hydraulic properties of shrink-swell soils

    Science.gov (United States)

    Stewart, Ryan D.; Abou Najm, Majdi R.; Rupp, David E.; Selker, John S.

    2016-10-01

    Shrink-swell soils crack and become compacted as they dry, changing properties such as bulk density and hydraulic conductivity. Multidomain models divide soil into independent realms that allow soil cracks to be incorporated into classical flow and transport models. Incongruously, most applications of multidomain models assume that the porosity distributions, bulk density, and effective saturated hydraulic conductivity of the soil are constant. This study builds on a recently derived soil shrinkage model to develop a new multidomain, dual-permeability model that can accurately predict variations in soil hydraulic properties due to dynamic changes in crack size and connectivity. The model only requires estimates of soil gravimetric water content and a minimal set of parameters, all of which can be determined using laboratory and/or field measurements. We apply the model to eight clayey soils, and demonstrate its ability to quantify variations in volumetric water content (as can be determined during measurement of a soil water characteristic curve) and transient saturated hydraulic conductivity, Ks (as can be measured using infiltration tests). The proposed model is able to capture observed variations in Ks of one to more than two orders of magnitude. In contrast, other dual-permeability models assume that Ks is constant, resulting in the potential for large error when predicting water movement through shrink-swell soils. Overall, the multidomain model presented here successfully quantifies fluctuations in the hydraulic properties of shrink-swell soil matrices, and are suitable for use in physical flow and transport models based on Darcy's Law, the Richards Equation, and the advection-dispersion equation.

  11. Thermal properties of degraded lowland peat-moorsh soils

    Science.gov (United States)

    Gnatowski, Tomasz

    2016-04-01

    Soil thermal properties, i.e.: specific heat capacity (c), thermal conductivity (K), volumetric heat capacity (C) govern the thermal environment and heat transport through the soil. Hence the precise knowledge and accurate predictions of these properties for peaty soils with high amount of organic matter are especially important for the proper forecasting of soil temperature and thus it may lead to a better assessment of the greenhouse gas emissions created by microbiological activity of the peatlands. The objective of the study was to develop the predictive models of the selected thermal parameters of peat-moorsh soils in terms of their potential applicability for forecasting changes of soil temperature in degraded ecosystems of the Middle Biebrza River Valley area. Evaluation of the soil thermal properties was conducted for the parameters: specific heat capacity (c), volumetric heat capacities of the dry and saturated soil (Cdry, Csat) and thermal conductivities of the dry and saturated soil (Kdry, Ksat). The thermal parameters were measured using the dual-needle probe (KD2-Pro) on soil samples collected from seven peaty soils, representing total 24 horizons. The surface layers were characterized by different degrees of advancement of soil degradation dependent on intensiveness of the cultivation practises (peaty and humic moorsh). The underlying soil layers contain peat deposits of different botanical composition (peat-moss, sedge-reed, reed and alder) and varying degrees of decomposition of the organic matter, from H1 to H7 (von Post scale). Based on the research results it has been shown that the specific heat capacity of the soils differs depending on the type of soil (type of moorsh and type of peat). The range of changes varied from 1276 J.kg-1.K-1 in the humic moorsh soil to 1944 J.kg-1.K-1 in the low decomposed sedge-moss peat. It has also been stated that in degraded peat soils with the increasing of the ash content in the soil the value of specific heat

  12. Relationships between some soil physical and chemical properties with magnetic properties in different soil moisture regimes in Golestan province

    Directory of Open Access Journals (Sweden)

    M. Valaee

    2016-09-01

    Full Text Available Introduction: Soil moisture regime refers to the presence or absence either of ground water or of water held at a tension of less than 1500 kPa in the soil or in specific horizons during periods of the year. It is the most important factor in soil formation, soil evolution and fertility affecting on crop production and management. Also, it widely is practical in soil classification and soil mapping. The soil moisture regime depends on the soil properties, climatic and weather conditions, characteristics of natural plant formations and, in cultivated soils, is affected by the characteristics of crops grown, as well as the cultivation practices. Determination of soil moisture regime within a landscape scale requires high information and data about moisture balance of soil profile during some years according to Soil Survey Manual (2010. This approach is very expensive, labor, time and cost consuming. Therefore, achievement to an alternative approach is seems essential to overcome these problems. The main hypothesis of this study was to use capability of magnetic susceptibility as a cheap and rapid technique could determine the soil moisture regimes. Magnetic properties of soils reflect the impacts of soil mineral composition, particularly the quantity of ferrimagnetic minerals such as maghemite and magnetite. Magnetic susceptibility measurements can serve a variety of applications including the changes in soil forming processes and ecological services, understanding of lithological effects, insight of sedimentation processes and soil drainage. Materials and Methods: This study was conducted in an area located between 36°46َ 10˝ and 37° 2’ 28˝ N latitudes, and 54° 29’ 31˝ and 55° 12’ 47˝ E longitudes in Golestan province, northern Iran. In the study region mean annual temperature varies from 12.4 to 19.4 °C. The average annual rainfall and evapotranspiration varies from 230 mm and 2335 mm in Inchebrun district (Aridic regime, to 732

  13. Effects of biochars on hydraulic properties of clayey soil

    Science.gov (United States)

    Zhen, Jingbo; Palladino, Mario; Lazarovitch, Naftali; Bonanomi, Giuliano; Battista Chirico, Giovanni

    2017-04-01

    Biochar has gained popularity as an amendment to improve soil hydraulic properties. Since biochar properties depend on feedstocks and pyrolysis temperatures used for its production, proper selection of biochar type as soil amendment is of great importance for soil hydraulic properties improvement. This study investigated the effects of eight types of biochar on physical and hydraulic properties of clayey soil. Biochars were derived from four different feedstocks (Alfalfa hay, municipal organic waste, corn residues and wood chip) pyrolyzed at two different temperatures (300 and 550 °C). Clayey soil samples were taken from Leone farm (40° 26' 15.31" N, 14° 59' 45.54" E), Italy, and were oven-dried at 105 °C to determine dry bulk density. Biochars were mixed with the clayey soil at 5% by mass. Bulk densities of the mixtures were also determined. Saturated hydraulic conductivities (Ks) of the original clayey soil and corresponding mixtures were measured by means of falling-head method. Soil water retention measurements were conducted for clayey soil and mixtures using suction table apparatus and Richards' plate with the pressure head (h) up to 12000 cm. van Genuchten retention function was selected to evaluate the retention characteristics of clayey soil and mixtures. Available water content (AWC) was calculated by field capacity (h = - 500 cm) minus wilting pointing (h = -12000 cm). The results showed that biochar addition decreased the bulk density of clayey soil. The Ks of clayey soil increased due to the incorporation of biochars except for waste and corn biochars pyrolyzed at 550 °C. AWC of soils mixed with corn biochar pyrolyzed at 300 °C and wood biochar pyrolyzed at 550 °C, increased by 31% and 7%, respectively. Further analysis will be conducted in combination of biochar properties such as specific surface area and total pore volume. Better understanding of biochar impact on clayey soil will be helpful in biochar selection for soil amendment and

  14. Importance of soil-water relation in assessment endpoint in bioremediated soils: Plant growth and soil physical properties

    International Nuclear Information System (INIS)

    Li, X.; Sawatsky, N.

    1995-01-01

    Much effort has been focused on defining the end-point of bioremediated soils by chemical analysis (Alberta Tier 1 or CCME Guideline for Contaminated Soils) or toxicity tests. However, these tests do not completely assess the soil quality, or the capability of soil to support plant growth after bioremediation. This study compared barley (Hordeum vulgare) growth on: (i) non-contaminated, agricultural topsoil, (2) oil-contaminated soil (4% total extractable hydrocarbons, or TEH), and (3) oil-contaminated soil treated by bioremediation (< 2% TEH). Soil physical properties including water retention, water uptake, and water repellence were measured. The results indicated that the growth of barley was significantly reduced by oil-contamination of agricultural topsoil. Furthermore, bioremediation did not improve the barley yield. The lack of effects from bioremediation was attributed to development of water repellence in hydrocarbon contaminated soils. There seemed to be a critical water content around 18% to 20% in contaminated soils. Above this value the water uptake by contaminated soil was near that of the agricultural topsoil. For lower water contents, there was a strong divergence in sorptivity between contaminated and agricultural topsoil. For these soils, water availability was likely the single most important parameter controlling plant growth. This parameter should be considered in assessing endpoint of bioremediation for hydrocarbon contaminated soils

  15. Effects of different soil management practices on soil properties and microbial diversity

    Science.gov (United States)

    Gajda, Anna M.; Czyż, Ewa A.; Dexter, Anthony R.; Furtak, Karolina M.; Grządziel, Jarosław; Stanek-Tarkowska, Jadwiga

    2018-01-01

    The effects of different tillage systems on the properties and microbial diversity of an agricultural soil was investigated. In doing so, soil physical, chemical and biological properties were analysed in 2013-2015, on a long-term field experiment on a loamy sand at the IUNG-PIB Experimental Station in Grabów, Poland. Winter wheat was grown under two tillage treatments: conventional tillage using a mouldboard plough and traditional soil tillage equipment, and reduced tillage based on soil crushing-loosening equipment and a rigid-tine cultivator. Chopped wheat straw was used as a mulch on both treatments. Reduced tillage resulted in increased water content throughout the whole soil profile, in comparison with conventional tillage. Under reduced tillage, the content of readily dispersible clay was also reduced, and, therefore, soil stability was increased in the toplayers, compared with conventional tillage. In addition, the beneficial effects of reduced tillage were reflected in higher soil microbial activity as measured with dehydrogenases and hydrolysis of fluorescein diacetate, compared with conventional tillage. Moreover, the polimerase chain reaction - denaturing gradient gel electrophoresis analysis showed that soil under reduced till-age had greater diversity of microbial communities, compared with conventionally-tilled soil. Finally, reduced tillage increased organic matter content, stability in water and microbial diversity in the top layer of the soil.

  16. Effect of cryogel on soil properties

    Science.gov (United States)

    Altunina, L. K.; Fufaeva, M. S.; Filatov, D. A.; Svarovskaya, L. I.; Rozhdestvenskii, E. A.; Gan-Erdene, T.

    2014-05-01

    Samples from the A1 and A1A2 horizons of sandy loamy gray forest soil containing 3.1% organic matter have been mixed with a 5% solution of polyvinyl alcohol (PVA) at a ratio of 7 : 1 under laboratory conditions. The samples were frozen at -20°C in a refrigerator; after a freezing-thawing cycle, the evaporation of water from their surface, their thermal conductivity coefficient, their elasticity modulus, and other properties were studied. It has been experimentally found that the thermal conductivity coefficient of cryostructured soil is lower than that of common soil by 25%. It has been shown that the cryostructured soil retains water for a longer time and that the water evaporation rate from its surface is significantly lower compared to the control soil. Cryogel has no negative effect on the catalase activity of soil; it changes the physical properties of soils and positively affects the population of indigenous soil microflora and the growth of the sown plants.

  17. Predicting Key Agronomic Soil Properties with UV-Vis Fluorescence Measurements Combined with Vis-NIR-SWIR Reflectance Spectroscopy: A Farm-Scale Study in a Mediterranean Viticultural Agroecosystem.

    Science.gov (United States)

    Vaudour, Emmanuelle; Cerovic, Zoran G; Ebengo, Dav M; Latouche, Gwendal

    2018-04-10

    For adequate crop and soil management, rapid and accurate techniques for monitoring soil properties are particularly important when a farmer starts up his activities and needs a diagnosis of his cultivated fields. This study aimed to evaluate the potential of fluorescence measured directly on 146 whole soil solid samples, for predicting key soil properties at the scale of a 6 ha Mediterranean wine estate with contrasting soils. UV-Vis fluorescence measurements were carried out in conjunction with reflectance measurements in the Vis-NIR-SWIR range. Combining PLSR predictions from Vis-NIR-SWIR reflectance spectra and from a set of fluorescence signals enabled us to improve the power of prediction of a number of key agronomic soil properties including SOC, N tot , CaCO₃, iron, fine particle-sizes (clay, fine silt, fine sand), CEC, pH and exchangeable Ca 2+ with cross-validation RPD ≥ 2 and R² ≥ 0.75, while exchangeable K⁺, Na⁺, Mg 2+ , coarse silt and coarse sand contents were fairly predicted (1.42 ≤ RPD < 2 and 0.54 ≤ R² < 0.75). Predictions of SOC, N tot , CaCO₃, iron contents, and pH were still good (RPD ≥ 1.8, R² ≥ 0.68) when using a single fluorescence signal or index such as SFR_R or FERARI, highlighting the unexpected importance of red excitations and indices derived from plant studies. The predictive ability of single fluorescence indices or original signals was very significant for topsoil: this is very important for a farmer who wishes to update information on soil nutrient for the purpose of fertility diagnosis and particularly nitrogen fertilization. These results open encouraging perspectives for using miniaturized fluorescence devices enabling red excitation coupled with red or far-red fluorescence emissions directly in the field.

  18. Predicting Key Agronomic Soil Properties with UV-Vis Fluorescence Measurements Combined with Vis-NIR-SWIR Reflectance Spectroscopy: A Farm-Scale Study in a Mediterranean Viticultural Agroecosystem

    Directory of Open Access Journals (Sweden)

    Emmanuelle Vaudour

    2018-04-01

    Full Text Available For adequate crop and soil management, rapid and accurate techniques for monitoring soil properties are particularly important when a farmer starts up his activities and needs a diagnosis of his cultivated fields. This study aimed to evaluate the potential of fluorescence measured directly on 146 whole soil solid samples, for predicting key soil properties at the scale of a 6 ha Mediterranean wine estate with contrasting soils. UV-Vis fluorescence measurements were carried out in conjunction with reflectance measurements in the Vis-NIR-SWIR range. Combining PLSR predictions from Vis-NIR-SWIR reflectance spectra and from a set of fluorescence signals enabled us to improve the power of prediction of a number of key agronomic soil properties including SOC, Ntot, CaCO3, iron, fine particle-sizes (clay, fine silt, fine sand, CEC, pH and exchangeable Ca2+ with cross-validation RPD ≥ 2 and R² ≥ 0.75, while exchangeable K+, Na+, Mg2+, coarse silt and coarse sand contents were fairly predicted (1.42 ≤ RPD < 2 and 0.54 ≤ R² < 0.75. Predictions of SOC, Ntot, CaCO3, iron contents, and pH were still good (RPD ≥ 1.8, R² ≥ 0.68 when using a single fluorescence signal or index such as SFR_R or FERARI, highlighting the unexpected importance of red excitations and indices derived from plant studies. The predictive ability of single fluorescence indices or original signals was very significant for topsoil: this is very important for a farmer who wishes to update information on soil nutrient for the purpose of fertility diagnosis and particularly nitrogen fertilization. These results open encouraging perspectives for using miniaturized fluorescence devices enabling red excitation coupled with red or far-red fluorescence emissions directly in the field.

  19. Optical Properties of Airborne Soil Organic Particles

    Energy Technology Data Exchange (ETDEWEB)

    Veghte, Daniel P. [William; China, Swarup [William; Weis, Johannes [Chemical; Department; Kovarik, Libor [William; Gilles, Mary K. [Chemical; Laskin, Alexander [Department

    2017-09-27

    Recently, airborne soil organic particles (ASOP) were reported as a type of solid organic particles emitted after water droplets impacted wet soils. Chemical constituents of ASOP are macromolecules such as polysaccharides, tannins, and lignin (derived from degradation of plants and biological organisms). Optical properties of ASOP were inferred from the quantitative analysis of the electron energy-loss spectra acquired over individual particles in the transmission electron microscope. The optical constants of ASOP are further compared with those measured for laboratory generated particles composed of Suwanee River Fulvic Acid (SRFA) reference material, which was used as a laboratory surrogate of ASOP. The particle chemical compositions were analyzed using energy dispersive x-ray spectroscopy, electron energy-loss spectroscopy, and synchrotron-based scanning transmission x-ray microscopy with near edge x-ray absorption fine structure spectroscopy. ASOP and SRFA exhibit similar carbon composition, but SRFA has minor contributions of S and Na. When ASOP are heated to 350 °C their absorption increases as a result of their pyrolysis and partial volatilization of semi-volatile organic constituents. The retrieved refractive index (RI) at 532 nm of SRFA particles, ASOP, and heated ASOP were 1.22-62 0.07i, 1.29-0.07i, and 1.90-0.38i, respectively. Compared to RISRFA, RIASOP has a higher real part but similar imaginary part. These measurements of ASOP optical constants suggest that they have properties characteristic of atmospheric brown carbon and therefore their potential effects on the radiative forcing of climate need to be assessed in atmospheric models.

  20. Estimating Infiltration Rates for a Loessal Silt Loam Using Soil Properties

    Science.gov (United States)

    M. Dean Knighton

    1978-01-01

    Soil properties were related to infiltration rates as measured by single-ringsteady-head infiltometers. The properties showing strong simple correlations were identified. Regression models were developed to estimate infiltration rate from several soil properties. The best model gave fair agreement to measured rates at another location.

  1. Prediction of soil properties for agricultural and environmental applications from infrared and X-ray soil spectral properties

    International Nuclear Information System (INIS)

    Towett, Erick Kibet

    2013-01-01

    Many of today's most pressing problems facing developing countries, such as food security, climate change, and environmental protection, require large area data on soil functional capacity. Conventional assessments (methods and measurements) of soil capacity to perform specific agricultural and environmental functions are time consuming and expensive. In addition, repeatability, reproducibility and accuracy of conventional soil analytical data are major challenges. New, rapid methods to quantify soil properties are needed, especially in developing countries where reliable data on soil properties is sparse, and to take advantage of new opportunities for digital soil mapping. Mid infrared diffuse reflectance spectroscopy (MIR) has already shown promise as a rapid analytical tool and there are new opportunities to include other high-throughput techniques, such as total X-ray fluorescence (TXRF), and X-ray diffraction (XRD) spectroscopy. In this study TXRF and XRD were tested in conjunction with IR to provide powerful diagnostic capabilities for the direct prediction of key soil properties for agricultural and environmental applications especially for Sub-Saharan Africa (SSA) soils. Optimal combinations of spectral methods for use in pedotransfer functions for low cost, rapid prediction of chemical and physical properties of African soils as well as prediction models for soil organic carbon and soil fertility properties (soil extractable nutrients, pH and exchangeable acidity) were tested in this study. This study has developed and tested a method for the use of TXRF for direct quantification of total element concentrations in soils using a TXRF (S2 PICOFOX trademark) spectrometer and demonstrated that TXRF could be used as a rapid screening tool for total element concentrations in soils assuming sufficient calibration measures are followed. The results of the current study have shown that TXRF can provide efficient chemical fingerprinting which could be further

  2. Prediction of soil properties for agricultural and environmental applications from infrared and X-ray soil spectral properties

    Energy Technology Data Exchange (ETDEWEB)

    Towett, Erick Kibet

    2013-12-09

    Many of today's most pressing problems facing developing countries, such as food security, climate change, and environmental protection, require large area data on soil functional capacity. Conventional assessments (methods and measurements) of soil capacity to perform specific agricultural and environmental functions are time consuming and expensive. In addition, repeatability, reproducibility and accuracy of conventional soil analytical data are major challenges. New, rapid methods to quantify soil properties are needed, especially in developing countries where reliable data on soil properties is sparse, and to take advantage of new opportunities for digital soil mapping. Mid infrared diffuse reflectance spectroscopy (MIR) has already shown promise as a rapid analytical tool and there are new opportunities to include other high-throughput techniques, such as total X-ray fluorescence (TXRF), and X-ray diffraction (XRD) spectroscopy. In this study TXRF and XRD were tested in conjunction with IR to provide powerful diagnostic capabilities for the direct prediction of key soil properties for agricultural and environmental applications especially for Sub-Saharan Africa (SSA) soils. Optimal combinations of spectral methods for use in pedotransfer functions for low cost, rapid prediction of chemical and physical properties of African soils as well as prediction models for soil organic carbon and soil fertility properties (soil extractable nutrients, pH and exchangeable acidity) were tested in this study. This study has developed and tested a method for the use of TXRF for direct quantification of total element concentrations in soils using a TXRF (S2 PICOFOX trademark) spectrometer and demonstrated that TXRF could be used as a rapid screening tool for total element concentrations in soils assuming sufficient calibration measures are followed. The results of the current study have shown that TXRF can provide efficient chemical fingerprinting which could be further

  3. Measurement of soil creep by inclinometer

    Science.gov (United States)

    Robert R. Ziemer

    1977-01-01

    Abstract - Continued inclinometer measurements at borehole sites installed in 1964 in northern California suggest that previously reported rates of soil creep are excessively high. Upon analysis of 35 access casings located in forested and grassland sites, no consistent direction of soil movement could be detected. In addition, no significant rate of soil creep could...

  4. Soil properties and preferential solute transport at the field scale

    DEFF Research Database (Denmark)

    Koestel, J K; Minh, Luong Nhat; Nørgaard, Trine

    An important fraction of water flow and solute transport through soil takes place through preferential flow paths. Although this had been already observed in the nineteenth century, it had been forgotten by the scientific community until it was rediscovered during the 1970s. The awareness...... of the relevance of preferential flow was broadly re-established in the community by the early 1990s. However, since then, the notion remains widespread among soil scientists that the occurrence and strength of preferential flow cannot be predicted from measurable proxy variables such as soil properties or land...

  5. Measuring Soil Moisture in Skeletal Soils Using a COSMOS Rover

    Science.gov (United States)

    Medina, C.; Neely, H.; Desilets, D.; Mohanty, B.; Moore, G. W.

    2017-12-01

    The presence of coarse fragments directly influences the volumetric water content of the soil. Current surface soil moisture sensors often do not account for the presence of coarse fragments, and little research has been done to calibrate these sensors under such conditions. The cosmic-ray soil moisture observation system (COSMOS) rover is a passive, non-invasive surface soil moisture sensor with a footprint greater than 100 m. Despite its potential, the COSMOS rover has yet to be validated in skeletal soils. The goal of this study was to validate measurements of surface soil moisture as taken by a COSMOS rover on a Texas skeletal soil. Data was collected for two soils, a Marfla clay loam and Chinati-Boracho-Berrend association, in West Texas. Three levels of data were collected: 1) COSMOS surveys at three different soil moistures, 2) electrical conductivity surveys within those COSMOS surveys, and 3) ground-truth measurements. Surveys with the COSMOS rover covered an 8000-h area and were taken both after large rain events (>2") and a long dry period. Within the COSMOS surveys, the EM38-MK2 was used to estimate the spatial distribution of coarse fragments in the soil around two COSMOS points. Ground truth measurements included coarse fragment mass and volume, bulk density, and water content at 3 locations within each EM38 survey. Ground-truth measurements were weighted using EM38 data, and COSMOS measurements were validated by their distance from the samples. There was a decrease in water content as the percent volume of coarse fragment increased. COSMOS estimations responded to both changes in coarse fragment percent volume and the ground-truth volumetric water content. Further research will focus on creating digital soil maps using landform data and water content estimations from the COSMOS rover.

  6. Soil physical properties on Venezuelan steeplands: Applications to soil conservation planning

    International Nuclear Information System (INIS)

    Delgado, F.

    2004-01-01

    This paper presents a framework to support decision making for soil conservation on Venezuelan steeplands. The general approach is based on the evaluation of two important land qualities: soil productivity and soil erosion risk, both closely related to soil physical properties. Soil productivity can be estimated from soil characteristics such as soil air-water relationships, soil impedances and soil fertility. On the other hand, soil erosion risk depends basically on soil hydrologic properties, rainfall aggressiveness and terrain slope. Two indexes are obtained from soil and land characteristics: soil productivity index (PI) and erosion risk index (ERI), each one evaluates the respective land quality. Subsequently, a matrix with these two qualities shows different land classes as well as soil conservation priorities, conservation requirements and proposed land uses. The paper shows also some applications of the soil productivity index as an approach to evaluate soil loss tolerance for soil conservation programs on tropical steeplands. (author)

  7. Effect of herbicides on microbiological properties of soil

    Directory of Open Access Journals (Sweden)

    Milošević Nada A.

    2002-01-01

    Full Text Available Microorganisms decompose herbicides and they may serve as bioindicators of soil changes following herbicide application. Certain microbial species may be used as bioherbicides. This study has shown that Azotobacter is most sensitive to herbicide application; it is, therefore, a reliable indicator of the biological value of soil. The numbers of this group of nitrogen-fixing bacteria decrease considerably in the period of 7-14 days after herbicide application. Simultaneously, the numbers of Actinomycetes and less so of fungi increase, indicating that these microorganisms use herbicides as sources of biogenous elements. Rate of herbicidal decomposition depends on the properties of the preparation applied herbicide dose as well as on the physical and chemical soil properties, soil moisture and temperature, ground cover, agrotechnical measures applied and the resident microbial population.

  8. Application of Terahertz Radiation to Soil Measurements: Initial Results

    Science.gov (United States)

    Dworak, Volker; Augustin, Sven; Gebbers, Robin

    2011-01-01

    Developing soil sensors with the possibility of continuous online measurement is a major challenge in soil science. Terahertz (THz) electromagnetic radiation may provide the opportunity for the measurement of organic material density, water content and other soil parameters at different soil depths. Penetration depth and information content is important for a functional soil sensor. Therefore, we present initial research on the analysis of absorption coefficients of four different soil samples by means of THz transmission measurements. An optimized soil sample holder to determine absorption coefficients was used. This setup improves data acquisition because interface reflections can be neglected. Frequencies of 340 GHz to 360 GHz and 1.627 THz to 2.523 THz provided information about an existing frequency dependency. The results demonstrate the potential of this THz approach for both soil analysis and imaging of buried objects. Therefore, the THz approach allows different soil samples to be distinguished according to their different absorption properties so that relations among soil parameters may be established in future. PMID:22163737

  9. Soil organic carbon dynamics jointly controlled by climate, carbon inputs, soil properties and soil carbon fractions.

    Science.gov (United States)

    Luo, Zhongkui; Feng, Wenting; Luo, Yiqi; Baldock, Jeff; Wang, Enli

    2017-10-01

    Soil organic carbon (SOC) dynamics are regulated by the complex interplay of climatic, edaphic and biotic conditions. However, the interrelation of SOC and these drivers and their potential connection networks are rarely assessed quantitatively. Using observations of SOC dynamics with detailed soil properties from 90 field trials at 28 sites under different agroecosystems across the Australian cropping regions, we investigated the direct and indirect effects of climate, soil properties, carbon (C) inputs and soil C pools (a total of 17 variables) on SOC change rate (r C , Mg C ha -1  yr -1 ). Among these variables, we found that the most influential variables on r C were the average C input amount and annual precipitation, and the total SOC stock at the beginning of the trials. Overall, C inputs (including C input amount and pasture frequency in the crop rotation system) accounted for 27% of the relative influence on r C , followed by climate 25% (including precipitation and temperature), soil C pools 24% (including pool size and composition) and soil properties (such as cation exchange capacity, clay content, bulk density) 24%. Path analysis identified a network of intercorrelations of climate, soil properties, C inputs and soil C pools in determining r C . The direct correlation of r C with climate was significantly weakened if removing the effects of soil properties and C pools, and vice versa. These results reveal the relative importance of climate, soil properties, C inputs and C pools and their complex interconnections in regulating SOC dynamics. Ignorance of the impact of changes in soil properties, C pool composition and C input (quantity and quality) on SOC dynamics is likely one of the main sources of uncertainty in SOC predictions from the process-based SOC models. © 2017 John Wiley & Sons Ltd.

  10. Evaluation of different field methods for measuring soil water infiltration

    Science.gov (United States)

    Pla-Sentís, Ildefonso; Fonseca, Francisco

    2010-05-01

    Soil infiltrability, together with rainfall characteristics, is the most important hydrological parameter for the evaluation and diagnosis of the soil water balance and soil moisture regime. Those balances and regimes are the main regulating factors of the on site water supply to plants and other soil organisms and of other important processes like runoff, surface and mass erosion, drainage, etc, affecting sedimentation, flooding, soil and water pollution, water supply for different purposes (population, agriculture, industries, hydroelectricity), etc. Therefore the direct measurement of water infiltration rates or its indirect deduction from other soil characteristics or properties has become indispensable for the evaluation and modelling of the previously mentioned processes. Indirect deductions from other soil characteristics measured under laboratory conditions in the same soils, or in other soils, through the so called "pedo-transfer" functions, have demonstrated to be of limited value in most of the cases. Direct "in situ" field evaluations have to be preferred in any case. In this contribution we present the results of past experiences in the measurement of soil water infiltration rates in many different soils and land conditions, and their use for deducing soil water balances under variable climates. There are also presented and discussed recent results obtained in comparing different methods, using double and single ring infiltrometers, rainfall simulators, and disc permeameters, of different sizes, in soils with very contrasting surface and profile characteristics and conditions, including stony soils and very sloping lands. It is concluded that there are not methods universally applicable to any soil and land condition, and that in many cases the results are significantly influenced by the way we use a particular method or instrument, and by the alterations in the soil conditions by the land management, but also due to the manipulation of the surface

  11. Effects of Chromolaena and Tithonia Mulches on Soil Properties

    African Journals Online (AJOL)

    User

    2 Department of Crop, Soil and Pest Management, Federal University of Technology, P.M.B. ... Chromolaena mulch produced higher values of soil chemical properties, leaf nutrient concentrations, ..... increased activities of beneficial soil fauna.

  12. Soil Properties Control Glyphosate Sorption in Soils Amended with Birch Wood Biochar

    DEFF Research Database (Denmark)

    Kahawaththa Gamage, Inoka Damayanthi Kumari; Moldrup, Per; Paradelo, Marcos

    2016-01-01

    Abstract Despite a contemporary interest in biochar application to agricultural fields to improve soil quality and long-term carbon sequestration, a number of potential side effects of biochar incorporation in field soils remain poorly understood, e.g., in relation to interactions...... with agrochemicals such as pesticides. In a fieldbased study at two experimental sites in Denmark (sandy loam soils at Risoe and Kalundborg), we investigated the influence of birch wood biochar with respect to application rate, aging (7–19 months), and physico- chemical soil properties on the sorption coefficient......, Kd (L kg−1), of the herbicide glyphosate. We measured Kd in equilibrium batch sorption experiments with triplicate soil samples from 20 field plots that received biochar at different application rates (0 to 100 Mg ha−1). The results showed that pure biochar had a lower glyphosate Kd value as compared...

  13. Soil chemical and physical properties that differentiate urban land-use and cover types

    Science.gov (United States)

    R.V. Pouyat; I.D. Yesilonis; J. Russell-Anelli; N.K. Neerchal

    2007-01-01

    We investigated the effects of land use and cover and surface geology on soil properties in Baltimore, MD, with the objectives to: (i) measure the physical and chemical properties of surface soils (0?10 cm) by land use and cover; and (ii) ascertain whether land use and cover explain differences in these properties relative to surface geology. Mean and median values of...

  14. Physical properties of magnesium affected soils in Colombia

    International Nuclear Information System (INIS)

    Garcia-Ocampo, A.

    2004-01-01

    Magnesium has some capacity to develop higher exchangeable sodium levels in clays and soil materials. The Mg +2 accumulation on the exchange complex of soils to a very high saturation levels affect their physical, chemical and biological properties. Colombia has a large area of these soils, located mainly in the main rivers valleys and in the Caribbean Region. In the Cauca River Valley there are about 117,000 hectares affected. There is a lack of information about the soil forming processes, the Mg +2 effects on soils, the type and source of compounds responsible for the magnesium enrichment, their relationship with the landscape and the way this accumulation occurs. To identify and quantify soil Mg +2 enriched areas over 2500 soil profiles from different landscape positions of the Cauca River Valley were studied. The information was processed to generate Mg-saturation maps, to identify the different soil profile types and to estimate the affected area. A topographic sequence from the alluvial inundation plain to the hills was used to explore the presence of diagnostic horizons and to determine the main soil characteristics and genetic, mineralogical or chemical evidences of soil forming processes. Two 180 kilometer transects parallel to the river were used to: a) study the type and source of Mg-compounds responsible for the Mg-enrichment and the way this accumulation occurs. b) the soil hydraulic properties like infiltration, saturated hydraulic conductivity and matrix potential at different depths were also measured. Samples of nine profiles were collected and the porosity and soil volume changes at different water content were examined. The program RETC was used for prediction of the hydraulic properties of non saturated soils. These properties involved the retention curve, the function of hydraulic conductivity and the diffusivity of the water in the soil. By grouping together the soil profiles, five main type of Mg-affected soils were identified as being

  15. Estimation of soil-soil solution distribution coefficient of radiostrontium using soil properties.

    Science.gov (United States)

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

    2009-02-01

    We propose a new approach for estimation of soil-soil solution distribution coefficient (K(d)) of radiostrontium using some selected soil properties. We used 142 Japanese agricultural soil samples (35 Andosol, 25 Cambisol, 77 Fluvisol, and 5 others) for which Sr-K(d) values had been determined by a batch sorption test and listed in our database. Spearman's rank correlation test was carried out to investigate correlations between Sr-K(d) values and soil properties. Electrical conductivity and water soluble Ca had good correlations with Sr-K(d) values for all soil groups. Then, we found a high correlation between the ratio of exchangeable Ca to Ca concentration in water soluble fraction and Sr-K(d) values with correlation coefficient R=0.72. This pointed us toward a relatively easy way to estimate Sr-K(d) values.

  16. Micronutrient Availability in Relation to Selected Soil Properties and landscape Position in Calcareous Soils of Golpayegan

    Directory of Open Access Journals (Sweden)

    Mojtaba Fathi

    2017-02-01

    Full Text Available Introduction: Variety of soil reactions govern the distribution of metal micronutrients that includes complexation with organic and inorganic ligands, ion exchange, adsorption and desorption processes, precipitation and dissolution of solids and acid-based equilibria. The relative importance of these reactions depends on many factors such as soil physical, chemical, and mineralogical properties and the nature of metal ions. Environmental factors such as climate, physiographic position, and soil development may affect variability of some soil properties and thereby nutrient availability. The present research was conducted to find relationships between Iron, manganese, zinc, and copper availability and some major soil properties, physiographic condition and soil development. Materials and Methods: Golpayegan region is located in northwest of Isfahan province in central Iran. The mean elevation of the studied area is 1790 above sea level. Annual precipitation was about 244mm and mean monthly temperature ranges from -6 in January to 34°C in August. The soils were developed on different physiographic conditions including piedmont plains, alluvial-fan, plateaus, and flood plains belonging to Entisols and Aridisols. Soil samples (0–60 cm were collected from 98 grid points with 2000m distance in the agricultural area of Golpayegan. Particle size distribution, calcium carbonate, organic carbon, available potassium and phosphorus of the soils were measured by SWRI standard methods. Available Zn, Cu, Mn, and Fe were determined by addition of 10 g soil to 20mL 0.005M diethylentriaminepentacetic‏. The solutions were shaken for 2 h at 25°C, centrifuged, filtered, and Fe, Mn, Zn, and Cu concentrations were measured by an atomic absorption spectrophotometer. Results Discussion: Studied soils were developed on calcareous material and about 60% of samples have more than 20% of calcium carbonate. Available Fe ranged from 1.4 to 6.5 mg kg-1 (mean 15.8 mg kg-1

  17. Assessment of Soil Health in Urban Agriculture: Soil Enzymes and Microbial Properties

    Directory of Open Access Journals (Sweden)

    Avanthi Deshani Igalavithana

    2017-02-01

    Full Text Available Urban agriculture has been recently highlighted with the increased importance for recreation in modern society; however, soil quality and public health may not be guaranteed because of continuous exposure to various pollutants. The objective of this study was to evaluate the soil quality of urban agriculture by soil microbial assessments. Two independent variables, organic and inorganic fertilizers, were considered. The activities of soil enzymes including dehydrogenase, β-glucosidase, arylsulfatase, urease, alkaline and acid phosphatases were used as indicators of important microbial mediated functions and the soil chemical properties were measured in the soils applied with organic or inorganic fertilizer for 10 years. Fatty acid methyl ester analysis was applied to determine the soil microbial community composition. Relatively higher microbial community richness and enzyme activities were found in the organic fertilizers applied soils as compared to the inorganic fertilizers applied soils. Principal component analysis explained the positive influence of organic fertilizers on the microbial community. The application of organic fertilizers can be a better alternative compared to inorganic fertilizers for the long-term health and security of urban agriculture.

  18. Measurement of soil moisture using gypsum blocks

    DEFF Research Database (Denmark)

    Friis Dela, B.

    the building. Consequently, measuring the moisture of the surrounding soil is of great importance for detecting the source of moisture in a building. Up till now, information has been needed to carry out individual calibrations for the different types of gypsum blocks available on the market and to account......For the past 50 years, gypsum blocks have been used to determine soil moisture content. This report describes a method for calibrating gypsum blocks for soil moisture measurements. Moisture conditions inside a building are strongly influenced by the moisture conditions in the soil surrounding...

  19. Constitutive Soil Properties for Mason Sand and Kennedy Space Center

    Science.gov (United States)

    Thomas, Michael A.; Chitty, Daniel E.

    2011-01-01

    Accurate soil models are required for numerical simulations of land landings for the Orion Crew Exploration Vehicle (CEV). This report provides constitutive material models for two soil conditions at Kennedy Space Center (KSC) and four conditions of Mason Sand. The Mason Sand is the test sand for LaRC s drop tests and swing tests of the Orion. The soil models are based on mechanical and compressive behavior observed during geotechnical laboratory testing of remolded soil samples. The test specimens were reconstituted to measured in situ density and moisture content. Tests included: triaxial compression, hydrostatic compression, and uniaxial strain. A fit to the triaxial test results defines the strength envelope. Hydrostatic and uniaxial tests define the compressibility. The constitutive properties are presented in the format of LSDYNA Material Model 5: Soil and Foam. However, the laboratory test data provided can be used to construct other material models. The soil models are intended to be specific to the soil conditions they were tested at. The two KSC models represent two conditions at KSC: low density dry sand and high density in-situ moisture sand. The Mason Sand model was tested at four conditions which encompass measured conditions at LaRC s drop test site.

  20. Effect of EDTA washing of metal polluted garden soils. Part I: Toxicity hazards and impact on soil properties.

    Science.gov (United States)

    Jelusic, Masa; Lestan, Domen

    2014-03-15

    We applied a multi-level approach assessing the quality, toxicity and functioning of Pb, Zn and Cd contaminated/remediated soil from a vegetable garden in Meza Valley, Slovenia. Contaminated soil was extracted with EDTA and placed into field experimental plots equipped with lysimeters. Soil properties were assessed by standard pedological analysis. Fractionation and leachability of toxic metals were analyzed by sequential extraction and TCLP and metal bioaccessibility by UBM tests. Soil respiration and enzyme activities were measured as indicators of soil functioning. Remediation reduced the metal burden by 80, 28 and 72% for Pb, Zn and Cd respectively, with a limited impact on soil pedology. Toxic metals associated with labile soil fractions were largely removed. No shifts between labile and residual fractions were observed during the seven months of the experiment. Initial metal leaching measured through lysimeters eventually ceased. However, remediation significantly diminished potential soil enzyme activity and no trends were observed of the remediated soil recovering its biological properties. Soil washing successfully removed available forms of Pb, Zn and Cd and thus lowered the human and environmental hazards of the remediated soil; however, remediation also extracted the trace elements essential for soil biota. In addition to reduced water holding capacity, soil health was not completely restored. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. Evaluation of soil conservation technologies from the perspective of selected physical soil properties and infiltration capacity of the soil

    Directory of Open Access Journals (Sweden)

    Miroslav Dumbrovský

    2011-01-01

    Full Text Available This paper evaluates different technologies of soil cultivation (conventional and minimization in terms of physical properties and water regime of soils, where infiltration of surface water is a major component of subsurface water. Soil physical properties (the current humidity, reduced bulk density, porosity, water retention capacity of soil, pore distribution and soil aeration is determined from soil samples taken from the organic horizon according to standard methodology. To observe the infiltration characteristics of surface layers of topsoil, the drench method (double ring infiltrometers was used. For the evaluation of field measurements of infiltration, empirical and physically derived equations by Kostiakov and Philip and the three-parameter Philip-type equation were used. The Philip three-parameter equation provides physical based parameters near the theoretical values, a good estimation of saturated hydraulic conductivity Ks and sorptivity C1. The parameter S of Philip’s equation describes the real value of the sorptivity of the soil. Experimental research work on the experimental plots H. Meziříčko proceeded in the years 2005–2008.

  2. Spectral Assessment of Soil Properties: Standoff Quantification of Soil Organic Matter Content in Surface Mineral Soils and Alaskan Peat

    Science.gov (United States)

    2017-08-01

    Soil Properties Standoff Quantification of Soil Organic Matter Content in Surface Mineral Soils and Alaskan Peat En gi ne er R es ea rc h an d D...ERDC 6.2 GRE ARTEMIS STO-R DRTSPORE ERDC TR-17-9 August 2017 Spectral Assessment of Soil Properties Standoff Quantification of Soil Organic...Matter Content in Surface Mineral Soils and Alaskan Peat Stacey L. Jarvis, Karen L. Foley, Robert M. Jones, Stephen D. Newman, and Robyn A. Barbato

  3. GEMAS: Unmixing magnetic properties of European agricultural soil

    Science.gov (United States)

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

    2016-04-01

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

  4. Determination of hydraulic properties of unsaturated soil via inverse modeling

    International Nuclear Information System (INIS)

    Kodesova, R.

    2004-01-01

    The method for determining the hydraulic properties of unsaturated soil with inverse modeling is presented. A modified cone penetrometer has been designed to inject water into the soil through a screen, and measure the progress of the wetting front with two tensiometer rings positioned above the screen. Cumulative inflow and pressure head readings are analyzed to obtain estimates of the hydraulic parameters describing K(h) and θ(h). Optimization results for tests at one side are used to demonstrate the possibility to evaluate either the wetting branches of the soil hydraulic properties, or the wetting and drying curves simultaneously, via analysis of different parts of the experiment. The optimization results are compared to the results of standard laboratory and field methods. (author)

  5. Applying soil property information for watershed assessment.

    Science.gov (United States)

    Archer, V.; Mayn, C.; Brown, S. R.

    2017-12-01

    The Forest Service uses a priority watershed scheme to guide where to direct watershed restoration work. Initial assessment was done across the nation following the watershed condition framework process. This assessment method uses soils information for a three step ranking across each 12 code hydrologic unit; however, the soil information used in the assessment may not provide adequate detail to guide work on the ground. Modern remote sensing information and terrain derivatives that model the environmental gradients hold promise of showing the influence of soil forming factors on watershed processes. These small scale data products enable the disaggregation of coarse scale soils mapping to show continuous soil property information across a watershed. When this information is coupled with the geomorphic and geologic information, watershed specialists can more aptly understand the controlling influences of drainage within watersheds and focus on where watershed restoration projects can have the most success. A case study on the application of this work shows where road restoration may be most effective.

  6. Litter decay controlled by temperature, not soil properties, affecting future soil carbon.

    Science.gov (United States)

    Gregorich, Edward G; Janzen, Henry; Ellert, Benjamin H; Helgason, Bobbi L; Qian, Budong; Zebarth, Bernie J; Angers, Denis A; Beyaert, Ronald P; Drury, Craig F; Duguid, Scott D; May, William E; McConkey, Brian G; Dyck, Miles F

    2017-04-01

    Widespread global changes, including rising atmospheric CO 2 concentrations, climate warming and loss of biodiversity, are predicted for this century; all of these will affect terrestrial ecosystem processes like plant litter decomposition. Conversely, increased plant litter decomposition can have potential carbon-cycle feedbacks on atmospheric CO 2 levels, climate warming and biodiversity. But predicting litter decomposition is difficult because of many interacting factors related to the chemical, physical and biological properties of soil, as well as to climate and agricultural management practices. We applied 13 C-labelled plant litter to soil at ten sites spanning a 3500-km transect across the agricultural regions of Canada and measured its decomposition over five years. Despite large differences in soil type and climatic conditions, we found that the kinetics of litter decomposition were similar once the effect of temperature had been removed, indicating no measurable effect of soil properties. A two-pool exponential decay model expressing undecomposed carbon simply as a function of thermal time accurately described kinetics of decomposition. (R 2  = 0.94; RMSE = 0.0508). Soil properties such as texture, cation exchange capacity, pH and moisture, although very different among sites, had minimal discernible influence on decomposition kinetics. Using this kinetic model under different climate change scenarios, we projected that the time required to decompose 50% of the litter (i.e. the labile fractions) would be reduced by 1-4 months, whereas time required to decompose 90% of the litter (including recalcitrant fractions) would be reduced by 1 year in cooler sites to as much as 2 years in warmer sites. These findings confirm quantitatively the sensitivity of litter decomposition to temperature increases and demonstrate how climate change may constrain future soil carbon storage, an effect apparently not influenced by soil properties. © 2016 Her Majesty

  7. The effects of land use types and soil depth on soil properties of ...

    African Journals Online (AJOL)

    The effects of land use types and soil depth on soil properties of Agedit watershed, Northwest Ethiopia. ... immediate intervention to protect the remnant forests and to replenish the degraded soil properties for sustainable agricultural productivity. Keywords: cultivation, deforestation, grazing, land management, soil fertility ...

  8. Shallow tillage effects on soil properties for temperate-region hard-setting soils

    DEFF Research Database (Denmark)

    Schjønning, Per; Thomsen, Ingrid Kaag

    2013-01-01

    Shallow tillage (ST; typically soil physical properties and hence modifies significantly the conditions for root growth and soil biotic activity as compared to mouldboard ploughing (MP; typically ∼25 cm). At field capacity in the spring, we measured cone...... quoted 1.5 MPa critical limit for root growth. Across the 11 field experiments, the untilled ST soil at 14–18 cm generally had lower ɛa and ka than the mechanically loosened soil at the same depth for MP. Also the specific air permeability (pore organization = ka/ɛa) was lower for ST than for MP. SOC...... penetration resistance (PR) of the top 40 cm soil and sampled intact soil cores (at 0–4 and 14–18 cm depths) in 11 field experiments (4–23% clay) after continued ST and MP management for mostly 4–8 years (two experiments >30 years). Bulk soil was sampled from 0 to ∼20 cm of the MP soil and from the two layers...

  9. Effective soil hydraulic properties in space and time: some field data analysis and modeling concepts

    Science.gov (United States)

    Soil hydraulic properties, which control surface fluxes and storage of water and chemicals in the soil profile, vary in space and time. Spatial variability above the measurement scale (e.g., soil area of 0.07 m2 or support volume of 14 L) must be upscaled appropriately to determine “effective” hydr...

  10. Effect of tillage on soil physical properties, growth and yield of ...

    African Journals Online (AJOL)

    ... ploughing plus harrowing plus bedding (PHB), on soil physical properties, growth and shoot yield of large-green leafy amaranth (Amaranth sp.). Soil moisture retention and infiltration rates were also measured in two cropping seasons. Soil moisture retention did not reflect any significant differences in the first and second ...

  11. Tillage system affects microbiological properties of soil

    Science.gov (United States)

    Delgado, A.; de Santiago, A.; Avilés, M.; Perea, F.

    2012-04-01

    Soil tillage significantly affects organic carbon accumulation, microbial biomass, and subsequently enzymatic activity in surface soil. Microbial activity in soil is a crucial parameter contributing to soil functioning, and thus a basic quality factor for soil. Since enzymes remain soil after excretion by living or disintegrating cells, shifts in their activities reflect long-term fluctuations in microbial biomass. In order to study the effects of no-till on biochemical and microbiological properties in comparison to conventional tillage in a representative soil from South Spain, an experiment was conducted since 1982 on the experimental farm of the Institute of Agriculture and Fisheries Research of Andalusia (IFAPA) in Carmona, SW Spain (37o24'07''N, 5o35'10''W). The soil at the experimental site was a very fine, montomorillonitic, thermic Chromic Haploxerert (Soil Survey Staff, 2010). A randomized complete block design involving three replications and the following two tillage treatments was performed: (i) Conventional tillage, which involved mouldboard plowing to a depth of 50 cm in the summer (once every three years), followed by field cultivation to a depth of 15 cm before sowing; crop residues being burnt, (ii) No tillage, which involved controlling weeds before sowing by spraying glyphosate and sowing directly into the crop residue from the previous year by using a planter with double-disk openers. For all tillage treatments, the crop rotation (annual crops) consisted of winter wheat, sunflower, and legumes (pea, chickpea, or faba bean, depending on the year), which were grown under rainfed conditions. Enzymatic activities (ß-glucosidase, dehydrogenase, aryl-sulphatase, acid phosphatase, and urease), soil microbial biomass by total viable cells number by acridine orange direct count, the density of cultivable groups of bacteria and fungi by dilution plating on semi-selective media, the physiological profiles of the microbial communities by BiologR, and the

  12. Influence of Height Waterlogging on Soil Physical Properties of Potential and Actual Acid Sulphate Soils

    Directory of Open Access Journals (Sweden)

    Arifin Fahmi

    2014-06-01

    Full Text Available Water management is main factor that determines the successful of rice cultivation in acid sulphate soil. Soil waterlogging determines the direction and rate of chemical, geochemical and biological reaction in the soil, indirectly these reactions may influence to the changes of soil psycal properties during soil waterlogging process. The experiment was aimed to study the changes of two type of acid sulphate soils physical properties during rice straw decomposition processes. The research was conducted in the greenhouse consisting of the three treatment factors using the completely randomized design with three replications. The first factor was soil type: potential acid sulphate soil (PASS and actual acid sulphate soil (AASS. The second factor was height of water waterlogging: 0.5-1.0 cm (muddy water–level condition and 4.0 cm from above the soil surface (waterlogged. The third factor was organic matter type: rice straw (RS, purun tikus (Eleocharis dulcis (PT and mixed of RS and PT (MX. Soil physical properties such as aggregate stability, total soil porosity, soil permeability, soil particle density and bulk density were observed at the end of experiment (vegetative maximum stage. The results showed that acid sulphate soil type had large effect on soil physicl properties, soil waterlogging decreased aggregate stability, soil particle density and bulk density both of soil type.

  13. Soil gas measurements at high permeabilities and below foundation depth

    International Nuclear Information System (INIS)

    Johner, H.U; Surbeck, H.

    2000-01-01

    We started a project of soil gas measurements beneath houses. Since the foundations of houses often lie deeper than 0.5 to 1 m - the depth where soil gas measurements are often made - the first approach was to apply the method developed previously to deeper soil layers. The radon availability index (RAI), which was defined empirically, proved to be a reliable indicator for radon problems in nearby houses. The extreme values of permeability, non-Darcy flow and scale dependence of permeability stimulated the development of a multi-probe method. A hydrological model was applied to model the soil gas transport. The soil gas measurements below foundation depth provided a wealth of new information. A good classification of soil properties could be achieved. If soil gas measurements are to be made, the low permeability layer has to be traversed. A minimum depth of 1 .5 m is suggested, profiles to below the foundation depth are preferable. There are also implications for mitigation works. A sub-slab suction system should reach the permeable layer to function well. This also holds for radon wells. If a house is located on a slope, it is most convenient to install the sub-slab suction system on the hillside, as the foundation reaches the deepest levels there

  14. Measuring and understanding soil water repellency through novel interdisciplinary approaches

    Science.gov (United States)

    Balshaw, Helen; Douglas, Peter; Doerr, Stefan; Davies, Matthew

    2017-04-01

    Food security and production is one of the key global issues faced by society. It has become evermore essential to work the land efficiently, through better soil management and agronomy whilst protecting the environment from air and water pollution. The failure of soil to absorb water - soil water repellency - can lead to major environmental problems such as increased overland flow and soil erosion, poor uptake of agricultural chemicals and increased risk of groundwater pollution due to the rapid transfer of contaminants and nutrient leaching through uneven wetting and preferential flow pathways. Understanding the causes of soil hydrophobicity is essential for the development of effective methods for its amelioration, supporting environmental stability and food security. Organic compounds deposited on soil mineral or aggregate surfaces have long been recognised as a major factor in causing soil water repellency. It is widely accepted that the main groups of compounds responsible are long-chain acids, alkanes and other organic compounds with hydrophobic properties. However, when reapplied to sands and soils, the degree of water repellency induced by these compounds and mixtures varied widely with compound type, amount and mixture, in a seemingly unpredictable way. Our research to date involves two new approaches for studying soil wetting. 1) We challenge the theoretical basis of current ideas on the measured water/soil contact angle measurements. Much past and current discussion involves Wenzel and Cassie-Baxter models to explain anomalously high contact angles for organics on soils, however here we propose that these anomalously high measured contact angles are a consequence of the measurement of a water drop on an irregular non-planar surface rather than the thermodynamic factors of the Cassie-Baxter and Wenzel models. In our analysis we have successfully used a much simpler geometric approach for non-flat surfaces such as soil. 2) Fluorescent and phosphorescent

  15. Manual for soil physical measurements; Version 3

    NARCIS (Netherlands)

    Stolte, J.

    1997-01-01

    Manuals are given for several laboratory methods for determining hydraulic conductivity, water retention and shrinkage characteristics of soil. Measurement techniques described are: the constant-head and falling-head methods for saturated conductivitythe drip infiltrometer for unsaturated

  16. Radar for Measuring Soil Moisture Under Vegetation

    Science.gov (United States)

    Moghaddam, Mahta; Moller, Delwyn; Rodriguez, Ernesto; Rahmat-Samii, Yahya

    2004-01-01

    A two-frequency, polarimetric, spaceborne synthetic-aperture radar (SAR) system has been proposed for measuring the moisture content of soil as a function of depth, even in the presence of overlying vegetation. These measurements are needed because data on soil moisture under vegetation canopies are not available now and are necessary for completing mathematical models of global energy and water balance with major implications for global variations in weather and climate.

  17. Studying soil properties using visible and near infrared spectral analysis

    Science.gov (United States)

    Moretti, S.; Garfagnoli, F.; Innocenti, L.; Chiarantini, L.

    2009-04-01

    This research is carried out inside the DIGISOIL Project, whose purposes are the integration and improvement of in situ and proximal measurement technologies, for the assessment of soil properties and soil degradation indicators, going form the sensing technologies to their integration and their application in digital soil mapping. The study area is located in the Virginio river basin, about 30 km south of Firenze, in the Chianti area, where soils with agricultural suitability have a high economic value connected to the production of internationally famous wines and olive oils. The most common soil threats, such as erosion and landslide, may determine huge economic losses, which must be considered in farming management practices. This basin has a length of about 23 km for a basin area of around 60,3 Km2. Geological formations outcropping in the area are Pliocene to Pleistocene marine and lacustrine sediments in beds with almost horizontal bedding. Vineyards, olive groves and annual crops are the main types of land use. A typical Mediterranean climate prevails with a dry summer followed by intense and sometimes prolonged rainfall in autumn, decreasing in winter. In this study, three types of VNIR and SWIR techniques, operating at different scales and in different environments (laboratory spectroscopy, portable field spectroscopy) are integrated to rapidly quantify various soil characteristics, in order to acquire data for assessing the risk of occurrence for typically agricultural practice-related soil threats (swelling, compaction, erosion, landslides, organic matter decline, ect.) and to collect ground data in order to build up a spectral library to be used in image analysis from air-borne and satellite sensors. Difficulties encountered in imaging spectroscopy, such as influence of measurements conditions, atmospheric attenuation, scene dependency and sampling representation are investigated and mathematical pre-treatments, using proper algorithms, are applied and

  18. Comparison among monitoring strategies to assess water flow dynamic and soil hydraulic properties in agricultural soils

    Energy Technology Data Exchange (ETDEWEB)

    Valdes-Abellan, J.; Jiménez-Martínez, J.; Candela, L.; Tamoh, K.

    2015-07-01

    Irrigated agriculture is usually performed in semi-arid regions despite scarcity of water resources. Therefore, optimal irrigation management by monitoring the soil is essential, and assessing soil hydraulic properties and water flow dynamics is presented as a first measure. For this purpose, the control of volumetric water content, θ, and pressure head, h, is required. This study adopted two types of monitoring strategies in the same experimental plot to control θ and h in the vadose zone: i) non-automatic and more time-consuming; ii) automatic connected to a datalogger. Water flux was modelled with Hydrus-1D using the data collected from both acquisition strategies independently (3820 daily values for the automatic; less than 1000 for the non-automatic). Goodness-of-fit results reported a better adjustment in case of automatic sensors. Both model outputs adequately predicted the general trend of θ and h, but with slight differences in computed annual drainage (711 mm and 774 mm). Soil hydraulic properties were inversely estimated from both data acquisition systems. Major differences were obtained in the saturated volumetric water content, θs, and the n and α van Genuchten model shape parameters. Saturated hydraulic conductivity, Ks, shown lower variability with a coefficient of variation range from 0.13 to 0.24 for the soil layers defined. Soil hydraulic properties were better assessed through automatic data acquisition as data variability was lower and accuracy was higher. (Author)

  19. Comparison among monitoring strategies to assess water flow dynamic and soil hydraulic properties in agricultural soils

    Directory of Open Access Journals (Sweden)

    Javier Valdes-Abellan

    2015-03-01

    Full Text Available Abstract Irrigated agriculture is usually performed in semi-arid regions despite scarcity of water resources. Therefore, optimal irrigation management by monitoring the soil is essential, and assessing soil hydraulic properties and water flow dynamics is presented as a first measure. For this purpose, the control of volumetric water content, θ, and pressure head, h, is required. This study adopted two types of monitoring strategies in the same experimental plot to control θ and h in the vadose zone: i non-automatic and more time-consuming; ii automatic connected to a datalogger. Water flux was modelled with Hydrus-1D using the data collected from both acquisition strategies independently (3820 daily values for the automatic; less than 1000 for the non-automatic. Goodness-of-fit results reported a better adjustment in case of automatic sensors. Both model outputs adequately predicted the general trend of θ and h, but with slight differences in computed annual drainage (711 mm and 774 mm. Soil hydraulic properties were inversely estimated from both data acquisition systems. Major differences were obtained in the saturated volumetric water content, θs, and the n and α van Genuchten model shape parameters. Saturated hydraulic conductivity, Ks, shown lower variability with a coefficient of variation range from 0.13 to 0.24 for the soil layers defined. Soil hydraulic properties were better assessed through automatic data acquisition as data variability was lower and accuracy was higher.

  20. VARIABILITY OF ARABLE AND FOREST SOILS PROPERTIES ON ERODED SLOPES

    Directory of Open Access Journals (Sweden)

    Paweł Wiśniewski

    2014-10-01

    Full Text Available The basic method of reducing soil and land erosion is a change of land use, for example, from arable to forest. Particularly effective as a protective role – according to the Polish law – soil-protecting forests. The thesis presents differences in the deformation of the basic soil properties on moraine slopes, depending on land use. There has been presented the function and the efficiency of the soil-protecting forests in erosion control. The soil cross section transects and soil analysis displayed that soil-protecting forests are making an essential soil cover protection from degradation, inter alia, limiting the decrease of humus content, reduction of upper soil horizons and soil pedons layer. On the afforested slopes it was stated some clear changes of grain size and chemical properties of soils in relation to adjacent slopes agriculturally used.

  1. ENZYME ACTIVITIES OF PADDY SOILS AND RELATIONSHIPS WITH THE SOIL PROPERTIES

    Directory of Open Access Journals (Sweden)

    Rıdvan KIZILKAYA

    1998-03-01

    Full Text Available This study was carried out to determine the effect of soil properties on enzyme activities of paddy soils, the sample of which were taken from Üçpınar, Harız, Doğancı, Kaygusuz, Emenli, Sarıköy and Gelemenağarı villages where rice cultivation is an intensive agricultural system. In this study, soil properties having effects on urease, phosphatase, ß-glucosidase and catalase enzyme activities were setforth. Urease enzyme activities of soil samples varied from 24.12 to 39.03 mg N 100 g dry soil -1 . Significant correlations were determined between urease enzyme activities and organic matter (r = 0.89**, extractable Mn (r = 0.74**, exchangable K (r = 0.73** and total P content of soil (r = 0.81*. Acid phosphatase enzyme activity varied between 3.00-17.44 mg phenol 100 g dry soil -1 , alkaline phosphatase enzyme activity between 12.00-25.53 mg phenol 100 g dry soil-1 . Exchangable Mg (r = 0.71* and extractable Cu (r = 0.74* were found to have positive effect on acid phosphatase enzyme activity and pH (r = 0.73*, exchangable Ca (r = 0.74*, exchangable Mg (r = 0.71*, exchangable total basic cations (r = 0.79* and extractable Cu (r = 0.70* had positive effects on alkaline phosphatase enzyme activity, whereas total P (r = - 0.84** affected the activity negatively. ß-glucosidase enzyme activity was measured to vary between 1.12-3.64 mg salingen 100 g dry soil -1 . It was also observed that extractable Zn content of soil samples (r = - 0.97** had negative effect on ß-glucosidase activity, wheras total exchangable acidic cations (r = 0.70* affected the activity positively. Catalase enzyme activities of soils changed between 5.25 - 9.00 mg O2 5 g dry soil -1 . Significant correlations were found between catalase activities and fraction of soils and extractable Fe content. Positive correlations, however, were determined between catalase activities and clay fraction (r = 0.82* and salt content (r = 0.83** of samples.

  2. Measurements of radon in soil gas

    International Nuclear Information System (INIS)

    Paschuk, Sergei A.; Correa, Janine Nicolosi; Schelin, Hugo R.; Barbosa, Laercio; Sadula, Tatyana; Matsuzaki, Cristiana A.

    2009-01-01

    Full text: After the decades of systematic and numerous studies performed at different countries of the World, it has been concluded that radon as well as its progeny is the main cause of lung cancer. It is well known that more than 50% of the effective annual radiation dose received by a human being is related to the radon and its progenies. Among the principle mechanisms that bring the radon inside the dwelling is the soil exhalation as well as exhalation and release from the water. Radon concentration in the soil and its transport (emanation, diffusion, advection and adsorption) to the surface depends on different physical, geological and ambient parameters such as the geology of the area, geochemical composition of the soil, its porosity and permeability, grain size, soil humidity, bottom sediments and inputs from streams, temperature, atmospheric pressure, etc. Since the main part of indoor radon originates in the soil, the measurements of radon concentration in soil gas have to be considered as an important tool and indicator of probable high levels of radon inside the dwellings. Present work describes the radon in soil gas measurements performed during the last two years in cooperation between the Laboratory of Applied Nuclear Physics of the Federal University of Technology (UTFPR), the Nuclear Technology Development Center (CDTN) and the Institute of Radiation Protection and Dosimetry (IRD) from the Brazilian Nuclear Energy Commission (CNEN). Following previously concluded measurements of radon concentration in dwellings and the measurements of 222 Rn activity in drinking water collected at artesian bores of Curitiba urban area, present step of activities has been dedicated to measurements of radon concentration in soil gas. Experimental setup was based on the Professional Radon Monitor (ALPHA GUARD) connected to specially developed for such measurements Soil Gas Probe through the air pump and filter system. The equipment was adjusted with air flow of 0

  3. Infiltration properties of soils during extreme precipitation in the catchment area of Litavka

    OpenAIRE

    Hubinger, Lukáš

    2013-01-01

    The aim of this work is the measurement of some selected soil parameters and hydraulic conductivity. By the evalution of these data is determined the resolution of selected soil properties on the base of these characteristics and also predisposition to surface runoff and erosion washes away during a certain rain intensity. This paper contain the comparison of the soil infiltration capacity at selected values of soil water saturation. From the rainfall data is determined the size, frequency, d...

  4. Density measures and additive property

    OpenAIRE

    Kunisada, Ryoichi

    2015-01-01

    We deal with finitely additive measures defined on all subsets of natural numbers which extend the asymptotic density (density measures). We consider a class of density measures which are constructed from free ultrafilters on natural numbers and study a certain additivity property of such density measures.

  5. Heavy metals content in degraded agricultural soils of a mountain region related to soil properties

    Science.gov (United States)

    Navarro-Pedreño, José; Belén Almendro-Candel, María; Gómez, Ignacio; Jordán, Manuel M.; Bech, Jaume; Zorpas, Antonis

    2017-04-01

    Agriculture has been practiced for long time in Mediterranean regions. Intensive agriculture and irrigation have developed mainly in the valleys and coastal areas. In the mountainous areas, dry farming has been practiced for centuries. Soils have been fertilized using mainly organic amendments. Plants extracted nutrients and other elements like heavy metals presented in soils and agricultural practices modified soil properties that could favor the presence of heavy metals. In this work, it has been checked the content of heavy metals in 100 agricultural soils samples of the NorthWest area of the province of Alicante (Spain) which has been long cultivated with cereals and olive trees, and now soils are abandoned and degraded because of the low agricultural yields. European policy has the aim to improve the sustainable agriculture and recover landscapes of mountain regions. So that, it is important to check the state of the soils (Marques et al. 2007). Soils samples (arable layer) were analyzed determining: pH (1:5, w/v, water extract), equivalent calcium carbonate content, organic matter by Walkley-Black method (Nelson and Sommers 1996), micronutrients (Cu, Fe, Mn, Zn) extracted with DTPA (Lindsay and Norvell, 1978) and measured by atomic absorption spectrometry, and total content of metals (Cd, Cr, Ni, Pb) measured in soil samples after microwave acid digestion (Moral et al. 1996), quantifying the content of metals by ICP analysis. The correlation between soil properties and metals. The results indicated that pH and carbonates are the most important properties of these soils correlated with the metals (both micronutrients and heavy metals). The available micronutrients (all of them) are close correlated with the pH and carbonates in soils. Moreover, heavy metals like Pb and Ni are related to available Mn and Zn. Keywords: pH, carbonates, heavy metals, abandoned soils. References: Lindsay,W.L., andW.A. Norvell. 1978. "Development of a DTPA Soil Test for Zinc, Iron

  6. Role of soil properties in sewage sludge toxicity to soil collembolans

    OpenAIRE

    Domene, X.

    2010-01-01

    Soil properties are one of the most important factors explaining the different toxicity results found in different soils. Although there is knowledge about the role of soil properties on the toxicity of individual chemicals, not much is known about its relevance for sewage sludge amendments. In particular little is known about the effect of soil properties on the toxicity modulation of these complex wastes. In addition, in most studies on sewage sludges the identity of the main substances lin...

  7. Novel evaporation experiment to determine soil hydraulic properties

    Directory of Open Access Journals (Sweden)

    K. Schneider

    2006-01-01

    Full Text Available A novel experimental approach to determine soil hydraulic material properties for the dry and very dry range is presented. Evaporation from the surface of a soil column is controlled by a constant flux of preconditioned air and the resulting vapour flux is measured by infrared absorption spectroscopy. The data are inverted under the assumptions that (i the simultaneous movement of water in the liquid and vapour is represented by Richards' equation with an effective hydraulic conductivity and that (ii the coupling between the soil and the well-mixed atmosphere can be modelled by a boundary layer with a constant transfer resistance. The optimised model fits the data exceptionally well. Remaining deviations during the initial phase of an experiment are thought to be well-understood and are attributed to the onset of the heat flow through the column which compensates the latent heat of evaporation.

  8. Saturation and porosity measurements of different soil samples by gamma ray transmission

    International Nuclear Information System (INIS)

    Akbal, S.; Filiz Baytas, A.

    2000-01-01

    Gamma-ray transmission methods have been used accurately for the study of the properties of soil samples. In this study, the soil samples were collected from various regions of Turkey and a Nal (TI) detector measured the attenuation of strongly collimated monoenergetic gamma beam (from Cs-137) through soil samples. The water saturation and porosity were therefore calculated from the transmission measurements for each soil sample. (authors)

  9. The Electrochemical Properties of Biochars and How They Affect Soil Redox Properties and Processes

    Directory of Open Access Journals (Sweden)

    Stephen Joseph

    2015-07-01

    Full Text Available Biochars are complex heterogeneous materials that consist of mineral phases, amorphous C, graphitic C, and labile organic molecules, many of which can be either electron donors or acceptors when placed in soil. Biochar is a reductant, but its electrical and electrochemical properties are a function of both the temperature of production and the concentration and composition of the various redox active mineral and organic phases present. When biochars are added to soils, they interact with plant roots and root hairs, micro-organisms, soil organic matter, proteins and the nutrient-rich water to form complex organo-mineral-biochar complexes Redox reactions can play an important role in the development of these complexes, and can also result in significant changes in the original C matrix. This paper reviews the redox processes that take place in soil and how they may be affected by the addition of biochar. It reviews the available literature on the redox properties of different biochars. It also reviews how biochar redox properties have been measured and presents new methods and data for determining redox properties of fresh biochars and for biochar/soil systems.

  10. Anaerobic N mineralization in paddy soils in relation to inundation management, physicochemical soil fractions, mineralogy and soil properties

    Science.gov (United States)

    Sleutel, Steven; Kader, Mohammed Abdul; Ara Begum, Shamim; De Neve, Stefaan

    2013-04-01

    Anaerobic N mineralization measured from (saturated) repacked soil cores from 25 paddy fields in Bangladesh and was previously found to negatively related to soil N content on a relative basis. This suggests that other factors like soil organic matter (SOM) quality or abiotic factors instead control the anaerobic N mineralization process. We therefore assessed different physical and chemical fractions of SOM, management factors and various soil properties as predictors for the net anaerobic N mineralization. 1° First, we assessed routinely analyzed soil parameters (soil N and soil organic carbon, texture, pH, oxalate- and pyrophosphate-extractable Fe, Al, and Mn, fixed-NH4 content). We found no significant influences of neither soil mineralogy nor the annual length of inundation on soil N mineralization. The anaerobic N mineralization correlated positively with Na-pyrophosphate-extractable Fe and negatively with pH (both at Presistant OM fraction, followed by extraction of mineral bound OM with 10%HF thereby isolating the HF-resistant OM. None of the physicochemical SOM fractions were found useful predictors anaerobic N mineralization. The linkage between these chemical soil N fractions and N supplying processes actually occurring in the soil thus appears to be weak. Regardless, we hypothesize that variation in strength of N-mineral and N-OM linkages is likely to explain variation in bio-availability of organic N and proneness to mineralization. Yet, in order to separate kinetically different soil N fractions we then postulated that an alternative approach would be required, which instead isolates soil N fractions on the basis of bonding strength. In this respect bonding strength should be seen as opposite of proneness to dissolution of released N into water, the habitat of soil microorganisms mediating soil N mineralization. We hypothesize that soil N extracted by water at increasing temperatures would reflect such N fractions with increasing bonding strength, in

  11. Grey water impact on soil physical properties

    Directory of Open Access Journals (Sweden)

    Miguel L. Murcia-Sarmiento

    2014-01-01

    Full Text Available Due to the increasing demand for food produced by the increase in population, water as an indispensable element in the growth cycle of plants every day becomes a fundamental aspect of production. The demand for the use of this resource is necessary to search for alternatives that should be evaluated to avoid potential negative impacts. In this paper, the changes in some physical properties of soil irrigated with synthetic gray water were evaluated. The experimental design involved: one factor: home water and two treatments; without treated water (T1 and treated water (T2. The variables to consider in the soil were: electrical conductivity (EC, exchangeable sodium percentage (ESP, average weighted diameter (MWD and soil moisture retention (RHS. The water used in drip irrigation high frequency was monitored by tensiometer for producing a bean crop (Phaseolous vulgaris L. As filtration system used was employed a unit composed of a sand filter (FLA and a subsurface flow wetland artificial (HFSS. The treatments showed significant differences in the PSI and the RHS. The FLA+HFSS system is an alternative to the gray water treatment due to increased sodium retention.

  12. Using the Rasch model as an objective and probabilistic technique to integrate different soil properties

    Science.gov (United States)

    Rebollo, Francisco J.; Jesús Moral García, Francisco

    2016-04-01

    Soil apparent electrical conductivity (ECa) is one of the simplest, least expensive soil measurements that integrates many soil properties affecting crop productivity, including, for instance, soil texture, water content, and cation exchange capacity. The ECa measurements obtained with a 3100 Veris sensor, operating in both shallow (0-30 cm), ECs, and deep (0-90 cm), ECd, mode, can be used as an additional and essential information to be included in a probabilistic model, the Rasch model, with the aim of quantifying the overall soil fertililty potential in an agricultural field. This quantification should integrate the main soil physical and chemical properties, with different units. In this work, the formulation of the Rasch model integrates 11 soil properties (clay, silt and sand content, organic matter -OM-, pH, total nitrogen -TN-, available phosphorus -AP- and potassium -AK-, cation exchange capacity -CEC-, ECd, and ECs) measured at 70 locations in a field. The main outputs of the model include a ranking of all soil samples according to their relative fertility potential and the unexpected behaviours of some soil samples and properties. In the case study, the considered soil variables fit the model reasonably, having an important influence on soil fertility, except pH, probably due to its homogeneity in the field. Moreover, ECd, ECs are the most influential properties on soil fertility and, on the other hand, AP and AK the less influential properties. The use of the Rasch model to estimate soil fertility potential (always in a relative way, taking into account the characteristics of the studied soil) constitutes a new application of great practical importance, enabling to rationally determine locations in a field where high soil fertility potential exists and establishing those soil samples or properties which have any anomaly; this information can be necessary to conduct site-specific treatments, leading to a more cost-effective and sustainable field

  13. Measuring environmental change in forest ecosystems by repeated soil sampling: A North American perspective

    Science.gov (United States)

    Gregory B. Lawrence; Ivan J. Fernandez; Daniel D. Richter; Donald S. Ross; Paul W. Hazlett; Scott W. Bailey; Rock Ouimet; Richard A. F. Warby; Arthur H. Johnson; Henry Lin; James M. Kaste; Andrew G. Lapenis; Timothy J. Sullivan

    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...

  14. Estimating saturated hydraulic conductivity and air permeability from soil physical properties using state-space analysis

    DEFF Research Database (Denmark)

    Poulsen, Tjalfe; Møldrup, Per; Nielsen, Don

    2003-01-01

    and gaseous chemicals in the vadose zone. In this study, three modeling approaches were used to identify the dependence of saturated hydraulic conductivity (K-S) and air permeability at -100 cm H2O soil-water potential (k(a100)) on soil physical properties in undisturbed soil: (i) Multiple regression, (ii......) ARIMA (autoregressive integrated moving average) modeling, and (iii) State-space modeling. In addition to actual soil property values, ARIMA and state-space models account for effects of spatial correlation in soil properties. Measured data along two 70-m-long transects at a 20-year old constructed......Estimates of soil hydraulic conductivity (K) and air permeability (k(a)) at given soil-water potentials are often used as reference points in constitutive models for K and k(a) as functions of moisture content and are, therefore, a prerequisite for predicting migration of water, air, and dissolved...

  15. Soil properties in old-growth Douglas-fir gaps in the western Cascade Mountains of Oregon

    Science.gov (United States)

    Robert P. Griffiths; Andrew N. Gray; Thomas A. Spies

    2010-01-01

    This study had three objectives: (1) to determine if there are correlations between aboveground vegetation and belowground soil properties within large 50-m-diameter gaps, (2) to determine how large gaps influence forest soils compared with nongap soils, and (3) to measure the effects of differently sized gaps on gap soils. Circular canopy gaps were created in old-...

  16. Distribution coefficients for 85Sr and 137Cs in Japanese agricultural soils and their correlations with soil properties

    International Nuclear Information System (INIS)

    Kamei-Ishikawa, N.; Uchida, S.; Tagami, K.

    2008-01-01

    In this work, soil-soil solution distribution coefficients (K d ) of Sr and Cs were obtained for 112 Japanese agricultural soil samples (50 paddy soil and 62 upland soil samples) using batch sorption test. The relationships between Sr- or Cs-K d values and soil properties were discussed. Furthermore, the amount of Cs fixed in soil was estimated for 22 selected soil samples using a sequential extraction method. Then, cross effects of some soil properties for Cs fixation were evaluated. (author)

  17. Vital soil; function, value and properties

    NARCIS (Netherlands)

    Doelman, P.; Eijsackers, H.J.P.

    2004-01-01

    Healthy soil, with active soil life, deters long-term soil degradation and ensures that geo-physical processes are undisturbed. Is the vitality of soil under threat due to human civilization? Or is it due to contamination, intensification, and deforestation? Vital Soil aims to look at the effects

  18. Soil friability - Concept, Assessment and Effects of Soil Properties and Management

    DEFF Research Database (Denmark)

    Munkholm, Lars Juhl

    Soil friability is a key soil physical property yielding valuable information on the ease of productin a favorable seed- and root beds during tillage operations. Therefore, soil friability is acrucial soil property in relation to the ability of soil to support plant growth and to minimzethe energy...... required for tillage. The topic has interested farmers and soil scientiest for centuries, but is was the paper by Utomo and Dexter (1981) that significantly put the topic on the soil science agenda. The awareness of soil friability is growing, both in practiceand in soil science. This must be viewed...... in the light of the present renewed focus on global food security together with a focus on fossil fuel consumption and greenhouse gas emissions in crop production. Certainly, the demand for well-functioning, arable soils is rising to meet the global challenges....

  19. Rheological properties of different minerals and clay soils

    Directory of Open Access Journals (Sweden)

    Dolgor Khaydapova

    2015-07-01

    Full Text Available Rheological properties of kaolinite, montmorillonite, ferralitic soil of the humid subtropics (Norfolk island, southwest of Oceania, alluvial clay soil of arid subtropics (Konyaprovince, Turkey and carbonate loess loam of Russian forest-steppe zone were determined. A parallel plate rheometer MCR-302 (Anton Paar, Austria was used in order to conduct amplitude sweep test. Rheological properties allow to assess quantitatively structural bonds and estimate structural resistance to a mechanical impact. Measurements were carried out on samples previously pounded and capillary humidified during 24 hours. In the amplitude sweep method an analyzed sample was placed between two plates. The upper plate makes oscillating motions with gradually extending amplitude. Software of the device allows to receive several rheological parameters such as elastic modulus (G’, Pa, viscosity modulus (G", Pa, linear viscoelasticity range (G’>>G”, and point of destruction of structure at which the elastic modulus becomes equal to the viscosity modulus (G’=G”- crossover. It was found out that in the elastic behavior at G '>> G " strength of structural links of kaolinite, alluvial clay soil and loess loam constituted one order of 105 Pa. Montmorillonit had a minimum strength - 104 Pa and ferrallitic soil of Norfolk island [has] - a maximum one -106 Pa. At the same time montmorillonite and ferralitic soil were characterized by the greatest plasticity. Destruction of their structure (G '= G" took place only in the cases when strain was reaching 11-12%. Destraction of the kaolinite structure happened at 5% of deformation and of the alluvial clay soil and loess loam - at 4.5%.

  20. Impacts of Solar PV Arrays on Physicochemical Properties of Soil

    Science.gov (United States)

    Cagle, A.; Choi, C. S.; Macknick, J.; Ravi, S.; Bickhart, R.

    2017-12-01

    The deployment of renewable energy technologies, such as solar photovoltaics (PV), is rapidly escalating. While PV can provide clean, renewable energy, there is uncertainty regarding its potential positive and/or negative impacts on the local environment. Specifically, its effects on the physicochemical properties of the underlying soil have not been systematically quantified. This study facilitates the discussion on the effects of PV installations related to the following questions: i. How do soil moisture, infiltration rates, total organic carbon, and nitrogen contents vary spatially under a PV array? ii. How do these physicochemical properties compare to undisturbed and adjacent land covered in native vegetation? iii. Are these variations statistically significant to provide insight on whether PV installations have beneficial or detrimental impacts on soil? We address these questions through field measurements of soil moisture, infiltration, grain particle size distribution, total organic carbon, and nitrogen content at a 1-MW solar PV array located at the National Renewable Energy Laboratory in Golden, Colorado. We collect data via multiple transects underneath the PV array as as well as in an adjacent plot of undisturbed native vegetation. Measurements are taken at four positions under the solar panels; the east-facing edge, center area under the panel, west-facing edge, and interspace between panel rows to capture differences in sun exposure as well as precipitation runoff of panels. Measurements are collected before and after a precipitation event to capture differences in soil moisture and infiltration rates. Results of this work can provide insights for research fields associated with the co-location of agriculture and PV installations as well as the long term ecological impacts of solar energy development. Trends in physicochemical properties under and between solar panels can affect the viability of co-location of commercial crops in PV arrays, the

  1. Fauna-associated changes in chemical and biochemical properties of soil.

    Science.gov (United States)

    Tripathi, G; Sharma, B M

    2006-12-01

    To study the impacts of abundance of woodlice, termites, and mites on some functional aspects of soil in order to elucidate the specific role of soil fauna in improving soil fertility in desert. Fauna-rich sites were selected as experimental sites and adjacent areas were taken as control. Soil samples were collected from both sites. Soil respiration was measured at both sites. The soil samples were sent to laboratory, their chemical and biochemical properties were analyzed. Woodlice showed 25% decrease in organic carbon and organic matter as compared to control site. Whereas termites and mites showed 58% and 16% decrease in organic carbon and organic matter. In contrast, available nitrogen (nitrate and ammonical both) and phosphorus exhibited 2-fold and 1.2-fold increase, respectively. Soil respiration and dehydrogenase activity at the sites rich in woodlice, termites and mites produced 2.5-, 3.5- and 2-fold increases, respectively as compared to their control values. Fauna-associated increase in these biological parameters clearly reflected fauna-induced microbial activity in soil. Maximum decrease in organic carbon and increase in nitrate-nitrogen and ammonical-nitrogen, available phosphorus, soil respiration and dehydrogenase activity were produced by termites and minimum by mites reflecting termite as an efficient soil improver in desert environment. The soil fauna-associated changes in chemical (organic carbon, nitrate-nitrogen, ammonical-nitrogen, phosphorus) and biochemical (soil respiration, dehydrogenase activity) properties of soil improve soil health and help in conservation of desert pedoecosystem.

  2. 3D-Digital soil property mapping by geoadditive models

    Science.gov (United States)

    Papritz, Andreas

    2016-04-01

    In many digital soil mapping (DSM) applications, soil properties must be predicted not only for a single but for multiple soil depth intervals. In the GlobalSoilMap project, as an example, predictions are computed for the 0-5 cm, 5-15 cm, 15-30 cm, 30-60 cm, 60-100 cm, 100-200 cm depth intervals (Arrouays et al., 2014). Legacy soil data are often used for DSM. It is common for such datasets that soil properties were measured for soil horizons or for layers at varying soil depth and with non-constant thickness (support). This poses problems for DSM: One strategy is to harmonize the soil data to common depth prior to the analyses (e.g. Bishop et al., 1999) and conduct the statistical analyses for each depth interval independently. The disadvantage of this approach is that the predictions for different depths are computed independently from each other so that the predicted depth profiles may be unrealistic. Furthermore, the error induced by the harmonization to common depth is ignored in this approach (Orton et al. 2016). A better strategy is therefore to process all soil data jointly without prior harmonization by a 3D-analysis that takes soil depth and geographical position explicitly into account. Usually, the non-constant support of the data is then ignored, but Orton et al. (2016) presented recently a geostatistical approach that accounts for non-constant support of soil data and relies on restricted maximum likelihood estimation (REML) of a linear geostatistical model with a separable, heteroscedastic, zonal anisotropic auto-covariance function and area-to-point kriging (Kyriakidis, 2004.) Although this model is theoretically coherent and elegant, estimating its many parameters by REML and selecting covariates for the spatial mean function is a formidable task. A simpler approach might be to use geoadditive models (Kammann and Wand, 2003; Wand, 2003) for 3D-analyses of soil data. geoAM extend the scope of the linear model with spatially correlated errors to

  3. Difficulties in the evaluation and measuring of soil water infiltration

    Science.gov (United States)

    Pla-Sentís, Ildefonso

    2013-04-01

    -Medellín (Colombia). ISSN 0124.177X Pla, I. 2011. Medición y evaluación de propiedades físicas de los suelos: dificultades y errores más frecuentes. II-Propiedades hidrológicas. Suelos Ecuatoriales 40 (2): 94-127 Reynolds W.D., B.T. Bowman, R.R. Brunke, C.F. Drury and C.S. Tan. 2000. Comparison of Tension Infiltrometer, Pressure Infiltrometer, and Soil Core Estimates of Saturated Hydraulic Conductivity . Soil Science Society of America Journal 64:478-484 Richards, L. A., 1952. Report of the Subcommittee on Permeability and Infiltration, Committee on Terminology, Soil Science Society of America: Soil Sci. Soc.America Proc., v. 16, p. 85-88. Segal, E., S.A.Bradford, P. Shouse; N. Lazarovich, and D. Corwin. 2008. Integration of Hard and Soft Data to Characterize Field-Scale Hydraulic Properties for Flow and Transport Studies. Vadose Zone J 7:878-889 Young, E. 1991. Infiltration measurements, a review. Hydrological processes 5: 309-320

  4. Soil thermal properties at Kalpakkam in coastal south India

    Indian Academy of Sciences (India)

    Time series of soil surface and subsurface temperatures, soil heat ux, net radiation, air temperature and wind speed were measured at two locations in Kalpakkam, coastal southeast India. The data were analysed to estimate soil thermal di usivity, thermal conductivity, volumetric heat capacity and soil heat ux. This paper ...

  5. Erodibility of calcareous soils as influenced by land use and intrinsic soil properties in a semiarid region of central Iran.

    Science.gov (United States)

    Ayoubi, Shamsollah; Mokhtari, Javad; Mosaddeghi, Mohammad Reza; Zeraatpisheh, Mojtaba

    2018-03-06

    The most important properties affecting the soil loss and runoff were investigated, and the effects of land use on the soil properties, together with the erodibility indices in a semiarid zone, central Iran, were evaluated. The locations of 100 positions were acquired by cLHS and 0-5-cm surface soil layer samples were used for laboratory analyses from the Borujen Region, Chaharmahal-Va-Bakhtiari Province, central Iran. To measure in situ runoff and soil erodibility of three different land uses comprising dryland, irrigated farming, and rangeland, a portable rainfall simulator was used. The results showed that the high variations (coefficient of variation, CV) were obtained for electrical conductivity (EC), mean weight diameter (MWD), soil organic carbon (SOC), and soil erodibility indices including runoff volume, soil loss, and sediment concentration (CV ~ 43.6-77.4%). Soil erodibility indices showed positive and significant correlations with bulk density and negative correlations with SOC, MWD, clay content, and soil shear strength in the area under investigation. The values of runoff in the dryland, irrigated farming, and rangeland were found 1.5, 28.9, and 58.7 cm 3 ; soil loss in the dryland, irrigated farming, and rangeland were observed 0.25, 2.96, and 76.8 g; and the amount of sediment concentration in the dryland, irrigated farming, and rangeland were found 0.01, 0.11, and 0.15 g cm -3 . It is suggested that further investigations should be carried out on soil erodibility and the potential of sediment yield in various land uses with varying topography and soil properties in semiarid regions of Iran facing the high risk of soil loss.

  6. Quantifying the heterogeneity of soil compaction, physical soil properties and soil moisture across multiple spatial scales

    Science.gov (United States)

    Coates, Victoria; Pattison, Ian; Sander, Graham

    2016-04-01

    England's rural landscape is dominated by pastoral agriculture, with 40% of land cover classified as either improved or semi-natural grassland according to the Land Cover Map 2007. Since the Second World War the intensification of agriculture has resulted in greater levels of soil compaction, associated with higher stocking densities in fields. Locally compaction has led to loss of soil storage and an increased in levels of ponding in fields. At the catchment scale soil compaction has been hypothesised to contribute to increased flood risk. Previous research (Pattison, 2011) on a 40km2 catchment (Dacre Beck, Lake District, UK) has shown that when soil characteristics are homogeneously parameterised in a hydrological model, downstream peak discharges can be 65% higher for a heavy compacted soil than for a lightly compacted soil. However, at the catchment scale there is likely to be a significant amount of variability in compaction levels within and between fields, due to multiple controlling factors. This research focusses in on one specific type of land use (permanent pasture with cattle grazing) and areas of activity within the field (feeding area, field gate, tree shelter, open field area). The aim was to determine if the soil characteristics and soil compaction levels are homogeneous in the four areas of the field. Also, to determine if these levels stayed the same over the course of the year, or if there were differences at the end of the dry (October) and wet (April) periods. Field experiments were conducted in the River Skell catchment, in Yorkshire, UK, which has an area of 120km2. The dynamic cone penetrometer was used to determine the structural properties of the soil, soil samples were collected to assess the bulk density, organic matter content and permeability in the laboratory and the Hydrosense II was used to determine the soil moisture content in the topsoil. Penetration results show that the tree shelter is the most compacted and the open field area

  7. Spectral estimation of soil properties in siberian tundra soils and relations with plant species composition

    DEFF Research Database (Denmark)

    Bartholomeus, Harm; Schaepman-Strub, Gabriela; Blok, Daan

    2012-01-01

    yields a good prediction model for K and a moderate model for pH. Using these models, soil properties are determined for a larger number of samples, and soil properties are related to plant species composition. This analysis shows that variation of soil properties is large within vegetation classes......Predicted global warming will be most pronounced in the Arctic and will severely affect permafrost environments. Due to its large spatial extent and large stocks of soil organic carbon, changes to organic matter decomposition rates and associated carbon fluxes in Arctic permafrost soils...

  8. LBA-ECO ND-10 Soil Properties of Pasture Chronosequences, Para, Brazil: 1997

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set provides the results of soil physical property and chemical measurements of samples collected from two pasture chronosequences (years since...

  9. LBA-ECO ND-10 Soil Properties of Pasture Chronosequences, Para, Brazil: 1997

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides the results of soil physical property and chemical measurements of samples collected from two pasture chronosequences (years since conversion...

  10. Predicting Soluble Nickel in Soils Using Soil Properties and Total Nickel.

    Science.gov (United States)

    Zhang, Xiaoqing; Li, Jumei; Wei, Dongpu; Li, Bo; Ma, Yibing

    2015-01-01

    Soil soluble nickel (Ni) concentration is very important for determining soil Ni toxicity. In the present study, the relationships between soil properties, total and soluble Ni concentrations in soils were developed in a wide range of soils with different properties and climate characteristics. The multiple regressions showed that soil pH and total soil Ni concentrations were the most significant parameters in predicting soluble Ni concentrations with the adjusted determination coefficients (Radj2) values of 0.75 and 0.68 for soils spiked with soluble Ni salt and the spiked soils leached with artificial rainwater to mimic field conditions, respectively. However, when the soils were divided into three categories (pH 8), they obtained better predictions with Radj2 values of 0.78-0.90 and 0.79-0.94 for leached and unleached soils, respectively. Meanwhile, the other soil properties, such as amorphous Fe and Al oxides and clay, were also found to be important for determining soluble Ni concentrations, indicating that they were also presented as active adsorbent surfaces. Additionally, the whole soil speciation including bulk soil properties and total soils Ni concentrations were analyzed by mechanistic speciation models WHAM VI and Visual MINTEQ3.0. It was found that WHAM VI provided the best predictions for the soils with pH 8. The Visual MINTEQ3.0 could provide better estimation for pH 8. These results indicated the possibility and applicability of these models to predict soil soluble Ni concentration by soil properties.

  11. Assessment of Index Properties and Bearing Capacities of Soils for ...

    African Journals Online (AJOL)

    Mrs Owoyemi

    on the physical properties and foundation bearing capacity of the soil in this area. This research aimed ... While many new structures are springing up daily in the .... plasticity soil. Most soil samples from both locations classify as A-2 -4 under the AASHTO classification system, rating as good subgrade materials. Bulk density ...

  12. Effects of sewage sludge application on selected soil properties and ...

    African Journals Online (AJOL)

    NSK/2) and one pit on the site that did not (NS/NSK) and described them before collecting soil samples from the genetic horizons of each pit for analysis of soil properties. Soil organic carbon (OC), microbial respiration, electrical conductivity (EC), ...

  13. Linkages between aggregate formation, porosity and soil chemical properties

    NARCIS (Netherlands)

    Regelink, I.C.; Stoof, C.R.; Rousseva, S.; Weng, L.; Lair, G.J.; Kram, P.; Nikolaidis, N.P.; Kercheva, M.; Banwart, S.; Comans, R.N.J.

    2015-01-01

    Linkages between soil structure and physical–chemical soil properties are still poorly understood due to the wide size-range at which aggregation occurs and the variety of aggregation factors involved. To improve understanding of these processes, we collected data on aggregate fractions, soil

  14. Influence of Soil Properties on Soldierless Termite Distribution

    Czech Academy of Sciences Publication Activity Database

    Bourguignon, T.; Drouet, T.; Šobotník, J.; Hanus, Robert; Roisin, Y.

    2015-01-01

    Roč. 10, č. 8 (2015), e0135341/1-e0135341/11 E-ISSN 1932-6203 Institutional support: RVO:61388963 Keywords : tropical termites * soil -feeding termites * soil properties * soil preference Subject RIV: EH - Ecology, Behaviour Impact factor: 3.057, year: 2015 http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0135341

  15. IMPACT OF OIL ON THE MECHANICAL PROPERTIES OF SOIL SUBSIDENCE

    Directory of Open Access Journals (Sweden)

    Алексей Алексеевич Бурцев

    2016-08-01

    Full Text Available The paper studied the effect of oil content on the mechanical properties of soil subsidence - Ek modulus and compressibility factor m0, obtained in the laboratory with the help of artificial impregnation oil soil samples. A comparison of the above parameters with samples of the same soil in the natural and water-saturated conditions has been perfomed.

  16. Relationship between the standing vegetation, soil properties and ...

    African Journals Online (AJOL)

    This study assessed the floristic composition, soil properties and the soil seedbank of the vegetation around the Iron smelting factory. This was with a view to determining the functional role played by soil chemical composition and the seed bank in the modifications of vegetation patterns. Five 100 m × 5 m plots were ...

  17. Soil profile property estimation with field and laboratory VNIR spectroscopy

    Science.gov (United States)

    Diffuse reflectance spectroscopy (DRS) soil sensors have the potential to provide rapid, high-resolution estimation of multiple soil properties. Although many studies have focused on laboratory-based visible and near-infrared (VNIR) spectroscopy of dried soil samples, previous work has demonstrated ...

  18. Spectral induced polarization (SIP) measurement of NAPL contaminated soils

    Science.gov (United States)

    Schwartz, N.; Huisman, J. A.; Furman, A.

    2010-12-01

    The potential applicability of spectral induce polarization (SIP) as a tool to map NAPLs (non aqueous phase liquids) contaminants at the subsurface lead researchers to investigate the electric signature of those contaminant on the spectral response. However, and despite the cumulative efforts, the effect of NAPL on the electrical properties of soil, and the mechanisms that control this effect are largely unknown. In this work a novel experiment is designed to further examine the effect of NAPL on the electrical properties of partially saturated soil. The measurement system that used is the ZEL-SIP04 impedance meter developed at the Forschungszentrum Julich, Germany. The system accurately (nominal phase precision of 0.1 mrad below 1 kHz) measures the phase and the amplitude of a material possessing a very low polarization (such as soil). The sample holder has a dimension of 60 cm long and 4.6 cm in diameter. Current and potential electrodes were made of brass, and while the current electrodes were inserted in full into the soil, the contact between the potential electrode and the soil was made through an Agarose bridge. Two types of soils were used: clean quartz sand, and a mixture of sand with clean Bentonite. Each soil (sandy or clayey) was mixed with water to get saturation degree of 30%. Following the mixture with water, NAPL was added and the composite were mixed again. Packing was done by adding and compressing small portions of the soil to the column. A triplicate of each mixture was made with a good reproducible bulk density. Both for the sandy and clayey soils, the results indicate that additions of NAPL decrease the real part of the complex resistivity. Additionally, for the sandy soil this process is time depended, and that a further decrease in resistivity develops over time. The results are analyzed considering geometrical factors: while the NAPL is electrically insulator, addition of NAPL to the soil is expected to increase the connectivity of the

  19. Towards soil property retrieval from space: Proof of concept using in situ observations

    Science.gov (United States)

    Bandara, Ranmalee; Walker, Jeffrey P.; Rüdiger, Christoph

    2014-05-01

    Soil moisture is a key variable that controls the exchange of water and energy fluxes between the land surface and the atmosphere. However, the temporal evolution of soil moisture is neither easy to measure nor monitor at large scales because of its high spatial variability. This is mainly a result of the local variation in soil properties and vegetation cover. Thus, land surface models are normally used to predict the evolution of soil moisture and yet, despite their importance, these models are based on low-resolution soil property information or typical values. Therefore, the availability of more accurate and detailed soil parameter data than are currently available is vital, if regional or global soil moisture predictions are to be made with the accuracy required for environmental applications. The proposed solution is to estimate the soil hydraulic properties via model calibration to remotely sensed soil moisture observation, with in situ observations used as a proxy in this proof of concept study. Consequently, the feasibility is assessed, and the level of accuracy that can be expected determined, for soil hydraulic property estimation of duplex soil profiles in a semi-arid environment using near-surface soil moisture observations under naturally occurring conditions. The retrieved soil hydraulic parameters were then assessed by their reliability to predict the root zone soil moisture using the Joint UK Land Environment Simulator model. When using parameters that were retrieved using soil moisture observations, the root zone soil moisture was predicted to within an accuracy of 0.04 m3/m3, which is an improvement of ∼0.025 m3/m3 on predictions that used published values or pedo-transfer functions.

  20. Environmental and management influences on temporal variability of near saturated soil hydraulic properties.

    Science.gov (United States)

    Bodner, G; Scholl, P; Loiskandl, W; Kaul, H-P

    2013-08-01

    Structural porosity is a decisive property for soil productivity and soil environmental functions. Hydraulic properties in the structural range vary over time in response to management and environmental influences. Although this is widely recognized, there are few field studies that determine dominant driving forces underlying hydraulic property dynamics. During a three year field experiment we measured temporal variability of soil hydraulic properties by tension infiltrometry. Soil properties were characterized by hydraulic conductivity, effective macroporosity and Kosugi's lognormal pore size distribution model. Management related influences comprised three soil cover treatment (mustard and rye vs. fallow) and an initial mechanical soil disturbance with a rotary harrow. Environmental driving forces were derived from meteorological and soil moisture data. Soil hydraulic parameters varied over time by around one order of magnitude. The coefficient of variation of soil hydraulic conductivity K(h) decreased from 69.5% at saturation to 42.1% in the more unsaturated range (- 10 cm pressure head). A slight increase in the Kosugi parameter showing pore heterogeneity was observed under the rye cover crop, reflecting an enhanced structural porosity. The other hydraulic parameters were not significantly influenced by the soil cover treatments. Seedbed preparation with a rotary harrow resulted in a fourfold increase in macroporosity and hydraulic conductivity next to saturation, and homogenized the pore radius distribution. Re-consolidation after mechanical loosening lasted over 18 months until the soil returned to its initial state. The post-tillage trend of soil settlement could be approximated by an exponential decay function. Among environmental factors, wetting-drying cycles were identified as dominant driving force explaining short term hydraulic property changes within the season (r 2  = 0.43 to 0.59). Our results suggested that beside considering average

  1. Continuous measurements of H2 and CO deposition onto soil: a laboratory soil chamber experiment

    Science.gov (United States)

    Ghosh, P.; Eiler, J.; Smith, N. V.; Thrift-Viveros, D. L.

    2004-12-01

    Hydrogen uptake in soil is the largest single component of the global budget of atmospheric H2, and is the most important parameter for predicting changes in atmospheric concentration with future changing sources (anthropogenic and otherwise). The rate of hydrogen uptake rate by soil is highly uncertain [1]. As a component of the global budget, it is simply estimated as the difference among estimates for other recognized sources and sinks, assuming the atmosphere is presently in steady state. Previous field chamber experiments [2] show that H2 deposition velocity varies complexly with soil moisture level, and possibly with soil organic content and temperature. We present here results of controlled soil chamber experiments on 3 different soil blocks (each ~20 x ~20 x ~21 cm) with a controlled range of moisture contents. All three soils are arid to semi arid, fine grained, and have organic contents of 10-15%. A positive air pressure (slightly higher than atmospheric pressure) and constant temperature and relative humidity was maintained inside the 10.7 liter, leak-tight plexiglass chamber, and a stream of synthetic air with known H2 concentration was continuously bled into the chamber through a needle valve and mass flow meter. H2, CO and CO2 concentrations were continuously analyzed in the stream of gas exiting the chamber, using a TA 3000 automated Hg-HgO reduced gas analyzer and a LI-820 CO2 gas analyzer. Our experimental protocol involved waiting until concentrations of analyte gases in the exiting gas stream reached a steady state, and documenting how that steady state varied with various soil properties and the rate at which gases were delivered to the chamber. The rate constants for H2 and CO consumption in the chamber were measured at several soil moisture contents. The calculated deposition velocities of H2 and CO into the soil are positively correlated with steady-state concentrations, with slopes and curvatures that vary with soil type and moisture level

  2. Soil Catena Properties of Daher Al- Jabal in South Syria

    Directory of Open Access Journals (Sweden)

    Hussam H. M. Husein

    2017-02-01

    Full Text Available Soil catena concept is a sequence of soils extends across relief positions and is developed from similar parent material. This study highlighted on the important aspects and properties of soil catena of Daher El-Jabal in Jabal Al-Arab mountainous area South eastern of Syria, by implementing pedologic study in 2010-2012. Six soil profiles have been studied along pedo-genetic transect in order to highlight the soil catena prevailing properties. The results reveal that the soil has formed from igneous basaltic parent casts, related to Neogen era, where reliefs had the key role in the developing of soil solum. Consequently, Entisols were dominated on eroded summits, Inceptisols on back slops and mountain flanks, Mollisols on depressions. Both water erosion of soil surface and leaching inside soil solum processes were responsible for variation of soil texture, as such soils showed evident of changing in particles size distribution as well as in clay content. Cation exchange capacity (CEC was less than moderate with domination of Magnesium cation. Soil trace elements were poor to somewhat poor. Soil pH values in general were low; which reflect the pedo-genic character of igneous parent material in which soil drifted from. In some cases, where soil body subjected to continuous leaching of soil bases, in particular calcium cation; soil profiles became totally freed from calcium carbonates. Accordingly soil problems related to downing of soil reaction (pH are more expected to be increasing by time. This is main reason for some physical diseases, which beginning arise on pomes fruits, particularly bitter pit.INTERNATIONAL JOURNAL OF ENVIRONMENT Volume-6, Issue-1, Dec-Feb 2016/17, page: 87-107

  3. Implementing a physical soil water flow model with minimal soil characteristics and added value offered by surface soil moisture measurements assimilation.

    Science.gov (United States)

    Chanzy, André

    2010-05-01

    Soil moisture is a key variable for many soil physical and biogeochemical processes. Its dynamic results from water fluxes in soil and at its boundaries, as well as soil water storage properties. If the water flows are dominated by diffusive processes, modelling approaches based on the Richard's equation or the Philip and de Vries coupled heat and water flow equations lead to a satisfactory representation of the soil moisture dynamic. However, It requires the characterization of soil hydraulic functions, the initialisation and the boundary conditions, which are expensive to obtain. The major problem to assess soil moisture for decision making or for representing its spatiotemporal evolution over complex landscape is therefore the lack of information to run the models. The aim of the presentation is to analyse how a soil moisture model can be implemented when only climatic data and basic soil information are available (soil texture, organic matter) and what would be the added of making a few soil moisture measurements. We considered the field scale, which is the key scale for decision making application (the field being the management unit for farming system) and landscape modelling (field size being comparable to the computation unit of distributed hydrological models). The presentation is limited to the bare soil case in order to limit the complexity of the system and the TEC model based on Philip and De Vries equations is used in this study. The following points are addressed: o the within field spatial variability. This spatial variability can be induced by the soil hydraulic properties and/or by the amount of infiltrated water induced by water rooting towards infiltration areas. We analyse how an effective parameterization of soil properties and boundary conditions can be used to simulate the field average moisture. o The model implementation with limited information. We propose strategies that can be implemented when information are limited to soil texture and

  4. Global soil-climate-biome diagram: linking soil properties to climate and biota

    Science.gov (United States)

    Zhao, X.; Yang, Y.; Fang, J.

    2017-12-01

    As a critical component of the Earth system, soils interact strongly with both climate and biota and provide fundamental ecosystem services that maintain food, climate, and human security. Despite significant progress in digital soil mapping techniques and the rapidly growing quantity of observed soil information, quantitative linkages between soil properties, climate and biota at the global scale remain unclear. By compiling a large global soil database, we mapped seven major soil properties (bulk density [BD]; sand, silt and clay fractions; soil pH; soil organic carbon [SOC] density [SOCD]; and soil total nitrogen [STN] density [STND]) based on machine learning algorithms (regional random forest [RF] model) and quantitatively assessed the linkage between soil properties, climate and biota at the global scale. Our results demonstrated a global soil-climate-biome diagram, which improves our understanding of the strong correspondence between soils, climate and biomes. Soil pH decreased with greater mean annual precipitation (MAP) and lower mean annual temperature (MAT), and the critical MAP for the transition from alkaline to acidic soil pH decreased with decreasing MAT. Specifically, the critical MAP ranged from 400-500 mm when the MAT exceeded 10 °C but could decrease to 50-100 mm when the MAT was approximately 0 °C. SOCD and STND were tightly linked; both increased in accordance with lower MAT and higher MAP across terrestrial biomes. Global stocks of SOC and STN were estimated to be 788 ± 39.4 Pg (1015 g, or billion tons) and 63 ± 3.3 Pg in the upper 30-cm soil layer, respectively, but these values increased to 1654 ± 94.5 Pg and 133 ± 7.8 Pg in the upper 100-cm soil layer, respectively. These results reveal quantitative linkages between soil properties, climate and biota at the global scale, suggesting co-evolution of the soil, climate and biota under conditions of global environmental change.

  5. Net sulfur mineralization potential in Swedish arable soils in relation to long-term treatment history and soil properties

    DEFF Research Database (Denmark)

    Boye, Kristin; Nilsson, S Ingvar; Eriksen, Jørgen

    2009-01-01

    accumulated net S mineralization (SAccMin) and a number of soil physical and chemical properties were determined. Treatments and soil differences in SAccMin, as well as correlations with soil variables, were tested with single and multivariate analyses. Long-term FYM application resulted in a significantly (p......The long-term treatment effect (since 1957-1966) of farmyard manure (FYM) application compared with crop residue incorporation was investigated in five soils (sandy loam to silty clay) with regards to the net sulfur (S) mineralization potential. An open incubation technique was used to determine...... = 0.012) higher net S mineralization potential, although total amounts of C, N, and S were not significantly (p soils within this treatment. The measured soil variables were not significantly correlated...

  6. Electric Properties Measurement of Lentil

    Directory of Open Access Journals (Sweden)

    Novák Ján

    2018-03-01

    Full Text Available This paper contains the results of the electric properties measurement of lentil set. Electric measurements with use of these materials are of fundamental importance in relation to the analysis of quantity of absorbed water and dielectric heating characteristics. The aim of this paper was to perform the measurements of conductivity, dielectric constant and loss tangent on samples of lentil, the electrical properties of which had not been sufficiently measured. Measurements were performed under various moisture contents, and the frequency of electric field ranged from 1 MHz to 16 MHz, using a Q meter with coaxial probe. It was concluded that conductivity, relative permittivity and loss tangent increased with an increase in moisture content, and dielectric constant and loss tangent decreased as the frequency of electric field increased.

  7. Relationships between soil erosion risk, soil use and soil properties in Mediterranean areas. A comparative study of three typical sceneries

    Science.gov (United States)

    Gil, Juan; Priego-Navas, Mercedes; Zavala, Lorena M.; Jordán, Antonio

    2013-04-01

    Generally, literature shows that the high variability of rainfall-induced soil erosion is related to climatic differences, relief, soil properties and land use. Very different runoff rates and soil loss values have been reported in Mediterranean cropped soils depending on soil management practices, but also in soils under natural vegetation types. OBJECTIVES The aim of this research is to study the relationships between soil erosion risk, soil use and soil properties in three typical Mediterranean areas from southern Spain: olive groves under conventional tillage, minimum tillage and no-till practices, and soils under natural vegetation. METHODS Rainfall simulation experiments have been carried out in order to assess the relationship between soil erosion risk, land use, soil management and soil properties in olive-cropped soils under different types of management and soils under natural vegetation type from Mediterranean areas in southern Spain RESULTS Results show that mean runoff rates decrease from 35% in olive grove soils under conventional tillage to 25% in olive (Olea europaea) grove soils with minimum tillage or no-till practices, and slightly over 22% in soils under natural vegetation. Moreover, considering the different vegetation types, runoff rates vary in a wide range, although runoff rates from soils under holm oak (Quercus rotundifolia), 25.70%, and marginal olive groves , 25.31%, are not significantly different. Results from soils under natural vegetation show that the properties and nature of the organic residues play a role in runoff characteristics, as runoff rates above 50% were observed in less than 10% of the rainfall simulations performed on soils with a organic layer. In contrast, more than half of runoff rates from bare soils reached or surpassed 50%. Quantitatively, average values for runoff water losses increase up to 2.5 times in unprotected soils. This is a key issue in the study area, where mean annual rainfall is above 600 mm

  8. Effect of a controlled burn on the thermophysical properties of a dry soil using a new model of soil heat flow and a new high temperature heat flux sensor

    Science.gov (United States)

    W. J. Massman; J. M. Frank

    2004-01-01

    Some fires can be beneficial to soils but, if a fire is sufficiently intense, soil can be irreversible altered. We measured soil temperatures and heat fluxes at several soil depths before, during, and after a controlled surface burn at Manitou Experimental Forest (southern Colorado, USA) to evaluate its effects on the soil's thermophysical properties (thermal...

  9. Plant species diversity affects infiltration capacity in an experimental grassland through changes in soil properties

    NARCIS (Netherlands)

    Fischer, C.; Tischer, J.; Roscher, C.; Eisenhauer, N.; Ravenek, J.; Gleixner, G.; Attinger, S.; Jensen, B.; Kroon, de H.; Mommer, L.; Scheu, S.; Hildebrandt, A.

    2015-01-01

    Background and aims Soil hydraulic properties drive water distribution and availability in soil. There exists limited knowledge of how plant species diversity might influence soil hydraulic properties. Methods We quantified the change in infiltration capacity affected by soil structural variables

  10. Measuring Soil Water Potential for Water Management in Agriculture: A Review

    Directory of Open Access Journals (Sweden)

    Marco Bittelli

    2010-05-01

    Full Text Available Soil water potential is a soil property affecting a large variety of bio-physical processes, such as seed germination, plant growth and plant nutrition. Gradients in soil water potential are the driving forces of water movement, affecting water infiltration, redistribution, percolation, evaporation and plants’ transpiration. The total soil water potential is given by the sum of gravity, matric, osmotic and hydrostatic potential. The quantification of the soil water potential is necessary for a variety of applications both in agricultural and horticultural systems such as optimization of irrigation volumes and fertilization. In recent decades, a large number of experimental methods have been developed to measure the soil water potential, and a large body of knowledge is now available on theory and applications. In this review, the main techniques used to measure the soil water potential are discussed. Subsequently, some examples are provided where the measurement of soil water potential is utilized for a sustainable use of water resources in agriculture.

  11. Chemical and microbial properties in contaminated soils around a magnesite mine in northeast China

    Science.gov (United States)

    D Yang; D-H Zeng; J Zhang; L-J Li; R. Mao

    2012-01-01

    We measured soil chemical and microbial properties at a depth of 0–20 cm among mine tailings, abandoned mined land, contaminated cropland, and uncontaminated cropland around a magnesite mine near Haicheng City, Liaoning Province, China. The objective was to clarify the impact of Mg on the soils. We found that soluble Mg2+ concentration and pH...

  12. Interaction Among Machine Traffic, Soil Physical Properties and Loblolly Pine Root Prolifereation in a Piedmont Soil

    Science.gov (United States)

    Emily A. Carter; Timothy P. McDonald

    1997-01-01

    The impact of forwarder traffic on soil physical properties was evaluated on a Gwinnett sandy loam, a commonly found soil of the Piedmont. Soil strength and saturated hydraulic conductivity were significantly altered by forwarder traffic, but reductions in air-filled porosity also occurred. Bulk density did not increase significantly in trafficked treatments. The...

  13. Impact of land management on soil structure and soil hydraulic properties

    Czech Academy of Sciences Publication Activity Database

    Kodešová, R.; Jirků, V.; Nikodem, A.; Mühlhanselová, M.; Žigová, Anna

    2010-01-01

    Roč. 12, - (2010) ISSN 1029-7006. [European Geosciences Union General Assembly 2010. 02.05.2010-07.05.2010, Wienna] R&D Projects: GA ČR GA526/08/0434 Institutional research plan: CEZ:AV0Z30130516 Keywords : land management * soil structure * soil hydraulic properties * micromorphology Subject RIV: DF - Soil Science

  14. Soil heating in chaparral fires: effects on soil properties, plant nutrients, erosion, and runoff

    Science.gov (United States)

    Leonard F. DeBano; Raymond M. Rice; Conrad C. Eugene

    1979-01-01

    This state-of-the-art report summarizes what is known about the effects of heat on soil during chaparral fires. It reviews the literature on the effects of such fires on soil properties, availabilty and loss of plant nutrients, soil wettability, erosion, and surface runoff. And it reports new data collected during recent prescribed burns and a wildfire in southern...

  15. Soil formation and soil biological properties post mining sites after coal mining in central Europe

    Czech Academy of Sciences Publication Activity Database

    Kaneda, Satoshi; Frouz, Jan; Krištůfek, Václav; Elhottová, Dana; Pižl, Václav; Starý, Josef; Háněl, Ladislav; Tajovský, Karel; Chroňáková, Alica

    2007-01-01

    Roč. 53, - (2007), s. 13 ISSN 0288-5840. [Annual Meeting Japanese Society of Soil Science and Plant Nutrition . 22.08.2007, Setagaya city] Institutional research plan: CEZ:AV0Z60660521 Keywords : soil formation * soil biological properties * post mining sites Subject RIV: EH - Ecology, Behaviour

  16. Soil physical property estimation from soil strength and apparent electrical conductivity sensor data

    Science.gov (United States)

    Quantification of soil physical properties through soil sampling and laboratory analyses is time-, cost-, and labor-consuming, making it difficult to obtain the spatially-dense data required for precision agriculture. Proximal soil sensing is an attractive alternative, but many currently available s...

  17. Soil thermal properties at Kalpakkam in coastal south India

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging Solutions)

    2012-02-01

    Feb 1, 2012 ... K Anandakumar1, R Venkatesan2, Thara V. Prabha1. 1Crop and ... Time series of soil surface and subsurface temperatures, soil heat flux, net radiation, air temperature and wind ... measured directly using thermal conductivity.

  18. Geoelectrical Soil Properties of Farmlands Located on Ancient River Floodplains in EL Paso County Texas

    Science.gov (United States)

    Pegues, J. G.; Kaip, G.; Doser, D. I.

    2013-12-01

    Farming in Rio Grande flood plain deposit soils has presented challenges concerning soil salinity, soil drainage and soil collapse. Typical soil forms include Saneli silted clay loam, Harkey loam, Harkey silky loam clay and Tigua silty clay. In the lower valley farmlands of Socorro, TX, cotton and alfalfa are the principal crops, but grain sorghum, corn and vegetable crops also are suitable. Pecan trees, as well as fruit trees suited to the climate, can be grown. Agrarians are faced with varying results of crop yields over relatively small stretches of land; for example, a 22 acre area can contain multiple soil inclusions. This study was conducted on a 22 acre tract of farmland which has recently undergone multiple geophysical testing analyses that include: magnetics, DC resistivity, gravity, and ground penetrating radar. Results will compare flood plain sedimentation qualities to agricultural soil classes through the identification of soil salinity and grain size. This investigation will focus on the testing of geo-electrical soil properties through resistivity assessment. Examination of the sight using a capacity coupled resistivity meter to measure the soil properties over various time periods will be conducted. The results will be compared with the other geophysical data to look for correlations that highlight soil properties.

  19. Soil measurements during HAPEX-Sahel intensive observation period.

    NARCIS (Netherlands)

    Cuenca, R.H.; Brouwer, J.; Chanzy, A.; Droogers, P.; Galle, S.; Gaze, S.R.; Sicot, M.; Stricker, J.N.M.; Angulo-Jaramillo, R.; Boyle, S.A.; Bromley, J.; Chebhouni, A.G.

    1997-01-01

    This article describes measurements made at each site and for each vegetation cover as part of the soils program for the HAPEX-Sahel regional scale experiment. The measurements were based on an initial sampling scheme and included profile soil water content, surface soil water content, soil water

  20. Relating soil geochemical properties to arsenic bioaccessibility

    Data.gov (United States)

    U.S. Environmental Protection Agency — soil element total concentration, soil pH and arsenic bioaccessibility values. This dataset is not publicly accessible because: EPA cannot release personally...

  1. Predicting radiocaesium sorption characteristics with soil chemical properties for Japanese soils.

    Science.gov (United States)

    Uematsu, Shinichiro; Smolders, Erik; Sweeck, Lieve; Wannijn, Jean; Van Hees, May; Vandenhove, Hildegarde

    2015-08-15

    The high variability of the soil-to-plant transfer factor of radiocaesium (RCs) compels a detailed analysis of the radiocaesium interception potential (RIP) of soil, which is one of the specific factors ruling the RCs transfer. The range of the RIP values for agricultural soils in the Fukushima accident affected area has not yet been fully surveyed. Here, the RIP and other major soil chemical properties were characterised for 51 representative topsoils collected in the vicinity of the Fukushima contaminated area. The RIP ranged a factor of 50 among the soils and RIP values were lower for Andosols compared to other soils, suggesting a role of soil mineralogy. Correlation analysis revealed that the RIP was most strongly and negatively correlated to soil organic matter content and oxalate extractable aluminium. The RIP correlated weakly but positively to soil clay content. The slope of the correlation between RIP and clay content showed that the RIP per unit clay was only 4.8 mmol g(-1) clay, about threefold lower than that for clays of European soils, suggesting more amorphous minerals and less micaceous minerals in the clay fraction of Japanese soils. The negative correlation between RIP and soil organic matter may indicate that organic matter can mask highly selective sorption sites to RCs. Multiple regression analysis with soil organic matter and cation exchange capacity explained the soil RIP (R(2)=0.64), allowing us to map soil RIP based on existing soil map information. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Variation of Desert Soil Hydraulic Properties with Pedogenic Maturity

    Science.gov (United States)

    Nimmo, J. R.; Perkins, K. S.; Mirus, B. B.; Schmidt, K. M.; Miller, D. M.; Stock, J. D.; Singha, K.

    2006-12-01

    Older alluvial desert soils exhibit greater pedogenic maturity, having more distinct desert pavements, vesicular (Av) horizons, and more pronounced stratification from processes such as illuviation and salt accumulation. These and related effects strongly influence the soil hydraulic properties. Older soils have been observed to have lower saturated hydraulic conductivity, and possibly greater capacity to retain water, but the quantitative effect of specific pedogenic features on the soil water retention or unsaturated hydraulic conductivity (K) curves is poorly known. With field infiltration/redistribution experiments on three different-aged soils developed within alluvial wash deposits in the Mojave National Preserve, we evaluated effective hydraulic properties over a scale of several m horizontally and to 1.5 m depth. We then correlated these properties with pedogenic features. The selected soils are (1) recently deposited sediments, (2) a soil of early Holocene age, and (3) a highly developed soil of late Pleistocene age. In each experiment we ponded water in a 1-m-diameter infiltration ring for 2.3 hr. For several weeks we monitored subsurface water content and matric pressure using surface electrical resistance imaging, dielectric-constant probes, heat-dissipation probes, and tensiometers. Analysis of these data using an inverse modeling technique gives the water retention and K properties needed for predictive modeling. Some properties show a consistent trend with soil age. Progressively more developed surface and near-surface features such as desert pavement and Av horizons are the likely cause of an observed consistent decline of infiltration capacity with soil age. Other properties, such as vertical flow retardation by layer contrasts, appear to have a more complicated soil-age dependence. The wash deposits display distinct depositional layering that has a retarding effect on vertical flow, an effect that may be less pronounced in the older Holocene soil

  3. Topsoil and subsoil properties influence phosphorus leaching from four agricultural soils.

    Science.gov (United States)

    Andersson, Helena; Bergström, Lars; Djodjic, Faruk; Ulén, Barbro; Kirchmann, Holger

    2013-01-01

    Eutrophication, a major problem in many fresh and brackish waters, is largely caused by nonpoint-source pollution by P from agricultural soils. This lysimeter study examined the influence of P content, physical properties, and sorption characteristics in topsoil and subsoil on P leaching measured during 21 mo in 1-m-long, undisturbed soil columns of two clay and two sandy soils. Total P losses during the period varied between 0.65 and 7.40 kg ha. Dissolved reactive P was the dominant form in leachate from the sandy soils and one clay soil, varying from 48 to 76%. Particulate P dominated in leachate from the other clay soil, where low pH (5.2) in the subsoil decreased aggregate stability and thereby probably increased the dispersion of clay particles. Phosphorus leaching was small from soils with high P sorption index (PSI) and low P saturation (35% of PSI) in the profile. High sorption capacity in the subsoil was more important for P leaching in sandy soils than in clay soils with macropore flow, where the effect of high sorption capacity was reduced due to less interaction between percolating water and the soil matrix. The results suggest that P leaching is greatly affected by subsoil properties and that topsoil studies, which dominate current research, are insufficient for assessing P leaching in many soils. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  4. INFLUENCES OF SOIL PROPERTIES ON CHROMIUM (III SORPTION

    Directory of Open Access Journals (Sweden)

    R. Salmasi, F. Salmasi

    2007-07-01

    Full Text Available Soil adsorbing properties reduce sorption ability of the metal, which in turn may influence decision for remediation at contaminated sites. The objective of this study is presentation of a model based on soil properties to estimate the sorption of Cr(III in chromium contaminated soils. Twenty uncontaminated soil samples, with properties similar to the contaminated soils were selected from around of city of Tabriz and treated with Cr as CrCl3. A multiple regression analysis with statgraph software was used to drive an expression that related Cr sorption to common soil properties. The results showed that four soil properties were important in determining the amount of Cr adsorbed by the soils including pH, cation exchange capacity, total inorganic carbon and clay content with nearly 80% variability in Cr sorption and a reasonable level of confidence by this model. The obtained model suggested that Cr(III sorption was enhanced by higher soil pH, more total inorganic carbon, more clay, and higher cation exchange capacity.

  5. Effect of quick lime on physicochemical properties of clay soil

    Directory of Open Access Journals (Sweden)

    Bessaim Mohammed Mustapha

    2018-01-01

    Full Text Available Clay soils are known for their water sensitivity, which causes irreparable damage to any structure built on this type of soil. In order to avoid such problem, it is necessary to use various improvement and stabilization methods such as treatment with lime. This process has been used successfully in the field for decades. The addition of lime generates various physicochemical reactions within the soil such as cation exchange and pozzolanic reactions which are largely responsible for the improvement of the soil in question. This paper presents a study concerning the variation of physicochemical properties of clayey soil with the addition of quicklime at different percentages. Experiments were performed on two clayey soils (CL type in order to investigate the influence of quicklime on Atterberg limits and pH. These tests were carried out in an attempt to study and follow the development and progression of various reactions occurred within the soil with various lime percentages. The results show that the addition of quicklime causes a significant improvement in soil properties by reducing plasticity and thereby improves the soil workability. It can also be found that the addition of lime increase pH of soil, which allow activating pozzolanic reactions who tend to stabilize the soil in question by formation of cementitious compounds. Finally, the pH can be considered as a relevant parameter who allows a better understanding of the reactions that occur in the soil matrix.

  6. Calibrating soil respiration measures with a dynamic flux apparatus using artificial soil media of varying porosity

    Science.gov (United States)

    John R. Butnor; Kurt H. Johnsen

    2004-01-01

    Measurement of soil respiration to quantify ecosystem carbon cyclingrequires absolute, not relative, estimates of soil CO2 efflux. We describe a novel, automated efflux apparatus that can be used to test the accuracy of chamber-based soil respiration measurements by generating known CO2 fluxes. Artificial soil is supported...

  7. Integrated assessment of space, time, and management-related variability of soil hydraulic properties

    Energy Technology Data Exchange (ETDEWEB)

    Es, H.M. van; Ogden, C.B.; Hill, R.L.; Schindelbeck, R.R.; Tsegaye, T.

    1999-12-01

    Computer-based models that simulate soil hydrologic processes and their impacts on crop growth and contaminant transport depend on accurate characterization of soil hydraulic properties. Soil hydraulic properties have numerous sources of variability related to spatial, temporal, and management-related processes. Soil type is considered to be the dominant source of variability, and parameterization is typically based on soil survey databases. This study evaluated the relative significance of other sources of variability: spatial and temporal at multiple scales, and management-related factors. Identical field experiments were conducted for 3 yr. at two sites in New York on clay loam and silt loam soils, and at two sites in Maryland on silt loam and sandy loam soils, all involving replicated plots with plow-till and no-till treatments. Infiltrability was determined from 2054 measurements using parameters, and Campbell's a and b parameters were determined based on water-retention data from 875 soil cores. Variance component analysis showed that differences among the sites were the most important source of variability for a (coefficient of variation, CV = 44%) and b (CV = 23%). Tillage practices were the most important source of variability for infiltrability (CV = 10%). For all properties, temporal variability was more significant than field-scale spatial variability. Temporal and tillage effects were more significant for the medium- and fine-textured soils, and correlated to initial soil water conditions. The parameterization of soil hydraulic properties solely based on soil type may not be appropriate for agricultural lands since soil-management factors are more significant. Sampling procedures should give adequate recognition to soil-management and temporal processes at significant sources of variability to avoid biased results.

  8. Soil disturbance as a grassland restoration measure

    DEFF Research Database (Denmark)

    Schnoor, Tim; Bruun, Hans Henrik; Olsson, Pål Axel

    2015-01-01

    Soil disturbance is recognized as an important driver of biodiversity in dry grasslands, and can therefore be implemented as a restoration measure. However, because community re-assembly following disturbance includes stochastic processes, a focus only on species richness or establishment success...... to experimental disturbance treatments (ploughing or rotavation), and the vegetation was surveyed during four subsequent years of succession. Treated plots were compared with control plots representing untreated grassland, as well as nearby plots characterized by plant communities representing the restoration...

  9. Influence of physical properties of soil on 137 Cs mobility

    International Nuclear Information System (INIS)

    Kanapickas, A.; Paulaitiene, I.; Mazeika, J.; Bauziene, I.

    2005-01-01

    A model to account for the mobility of radiocesium in soil is presented. The model requires a minimal set of coefficients that describe radiocesium migration and fixation rates, which can be related to physical soil properties. The peculiarities of experimental radiocesium profiles in soil are explained by the composition of soil, which affects the radiocesium fixation rate. It is shown that the migration of radiocesium in soil is governed by vertical convection of a mobile form, whereas diffusion is a slower process due to strong fixation. The results show that the velocity of vertical migration downward of mobile radiocesium can be set constant, because the overall migration rate depends on fixation. Modeling of experimental radiocesium soil profiles suggests that organic (humic) layers with reduced mineral content and humidity have a high radiocesium fixation rate. Soil structure that maintains high soil humidity and mineral content has an increased cesium exchangeability and. consequently, higher radiocesium mobility. (author)

  10. The neutronic method for measuring soil moisture

    International Nuclear Information System (INIS)

    Couchat, Ph.

    1967-01-01

    The three group diffusion theory being chosen as the most adequate method for determining the response of the neutron soil moisture probe, a mathematical model is worked out using a numerical calculation programme with Fortran IV coding. This model is fitted to the experimental conditions by determining the effect of different parameters of measuring device: channel, fast neutron source, detector, as also the soil behaviour under neutron irradiation: absorbers, chemical binding of elements. The adequacy of the model is tested by fitting a line through the image points corresponding to the couples of experimental and theoretical values, for seven media having different chemical composition: sand, alumina, line stone, dolomite, kaolin, sandy loam, calcareous clay. The model chosen gives a good expression of the dry density influence and allows α, β, γ and δ constants to be calculated for a definite soil according to the following relation which gives the count rate of the soil moisture probe: N = (α ρ s +β) H v +γ ρ s + δ. (author) [fr

  11. Soil properties evolution after irrigation with reclaimed water

    Science.gov (United States)

    Leal, M.; González-Naranjo, V.; de Miguel, A.; Martínez-Hernández, V.; Lillo, J.

    2012-04-01

    Many arid and semi-arid countries are forced to look for new and alternative water sources. The availability of suitable quality water for agriculture in these regions often is threatened. In this context of water scarcity, the reuse of treated wastewater for crop irrigation could represent a feasible solution. Through rigorous planning and management, irrigation with reclaimed water presents some advantages such as saving freshwater, reducing wastewater discharges into freshwater bodies and decreasing the amount of added fertilizers due to the extra supply of nutrients by reclaimed water. The current study, which involves wastewater reuse in agriculture, has been carried out in the Experimental Plant of Carrión de los Céspedes (Sevile, Spain). Here, two survey parcels equally designed have been cultivated with Jatropha curcas L, a bioenergetic plant and a non-interfering food security crop. The only difference between the two parcels lies on the irrigation water quality: one is irrigated with groundwater and another one with reclaimed water. The main aim of this study focuses on analysing the outstanding differences in soil properties derived from irrigation with two water qualities, due to their implications for plant growth. To control and monitor the soil variables, soil samples were collected before and after irrigation in the two parcels. pH, electrical conductivity, cation exchange capacity, exchangeable cations (Ca2+, Mg2+, Na+ and K+), kjeldahl nitrogen, organic matter content and nutrients (boron, phosphorus, nitrogen, potassium) were measured. Data were statistically analyzed using the R package. To evaluate the variance ANOVA test was used and to obtain the relations between water quality and soil parameters, Pearson correlation coefficient was computed. According to other authors, a decrease in the organic matter content and an increase of parameters such as pH, electrical conductivity and some exchangeable cations were expected. To date and after

  12. A Preliminary Study of the Application of Electromagnetic Conductivity Meter on Soil Properties of Paddy Cultivation Areas at Wue Village, Jantho, Aceh Besar District, Indonesia

    OpenAIRE

    Marwan,

    2015-01-01

    Conventional soil sampling is time consuming and requires meticulous laboratory analysis. Hence, mapping of soil apparent in respect to electrical conductivity (ECa) has been developed to identify areas of contrasting soil properties. Such ECa values are represent measures of soil properties. The sensor system, GF Instrument model CMD-4 were used to analyze soil physical properties. This system consists of three important parts, ECa sensor, data logger and Global Positioning System (DGPS) rec...

  13. Sorption of citalopram, irbesartan and fexofenadine in soils: Estimation of sorption coefficients from soil properties.

    Science.gov (United States)

    Klement, Aleš; Kodešová, Radka; Bauerová, Martina; Golovko, Oksana; Kočárek, Martin; Fér, Miroslav; Koba, Olga; Nikodem, Antonín; Grabic, Roman

    2018-03-01

    The sorption of 3 pharmaceuticals, which may exist in 4 different forms depending on the solution pH (irbesartan in cationic, neutral and anionic, fexofenadine in cationic, zwitter-ionic and anionic, and citalopram cationic and neutral), in seven different soils was studied. The measured sorption isotherms were described by Freundlich equations, and the sorption coefficients, K F (for the fixed n exponent for each compound), were related to the soil properties to derive relationships for estimating the sorption coefficients from the soil properties (i.e., pedotransfer rules). The largest sorption was obtained for citalopram (average K F value for n = 1 was 1838 cm 3  g -1 ) followed by fexofenadine (K F  = 35.1 cm 3/n μg 1-1/n g -1 , n = 1.19) and irbesartan (K F  = 3.96 cm 3/n μg 1-1/n g -1 , n = 1.10). The behavior of citalopram (CIT) in soils was different than the behaviors of irbesartan (IRB) and fexofenadine (FEX). Different trends were documented according to the correlation coefficients between the K F values for different compounds (R IRB,FEX  = 0.895, p-valuesoil properties in the pedotransfer functions. While the K F value for citalopram was positively related to base cation saturation (BCS) or sorption complex saturation (SCS) and negatively correlated to the organic carbon content (Cox), the K F values of irbesartan and fexofenadine were negatively related to BCS, SCS or the clay content and positively related to Cox. The best estimates were obtained by combining BCS and Cox for citalopram (R 2  = 93.4), SCS and Cox for irbesartan (R 2  = 96.3), and clay content and Cox for fexofenadine (R 2  = 82.9). Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Research Note:Determination of soil hydraulic properties using pedotransfer functions in a semi-arid basin, Turkey

    Directory of Open Access Journals (Sweden)

    M. Tombul

    2004-01-01

    Full Text Available Spatial and temporal variations in soil hydraulic properties such as soil moisture q(h and hydraulic conductivity K(q or K(h, may affect the performance of hydrological models. Moreover, the cost of determining soil hydraulic properties by field or laboratory methods makes alternative indirect methods desirable. In this paper, various pedotransfer functions (PTFs are used to estimate soil hydraulic properties for a small semi-arid basin (Kurukavak in the north-west of Turkey. The field measurements were a good fit with the retention curve derived using Rosetta SSC-BD for a loamy soil. To predict parameters to describe soil hydraulic characteristics, continuous PTFs such as Rosetta SSC-BD (Model H3 and SSC-BD-q33q1500 (Model H5 have been applied. Using soil hydraulic properties that vary in time and space, the characteristic curves for three soil types, loam, sandy clay loam and sandy loam have been developed. Spatial and temporal variations in soil moisture have been demonstrated on a plot and catchment scale for loamy soil. It is concluded that accurate site-specific measurements of the soil hydraulic characteristics are the only and probably the most promising method to progress in the future. Keywords: soil hydraulic properties, soil characteristic curves, PTFs

  15. Effects of Fuel Oil on the Geotechnical Properties of Clay Soil

    Directory of Open Access Journals (Sweden)

    Mahdi Obaid Karkush

    2017-08-01

    Full Text Available The present study highlights the effects of medium fuel oil (MFO on the chemical, physical and mechanical properties of clay soil samples (disturbed and undisturbed obtained from the site of the electrical power plant in the campus of the University of Baghdad at Al-Jadriah district in Baghdad/Iraq. The soil sample was classified according to the unified soil classification system (USCS as CL and described as lean clay of low plasticity. The medium fuel oil is an industrial wastewater disposed as a byproduct from the fuel used in the electricity power plant. The soil samples are artificially contaminated with two percentages of medium fuel oil, 10 and 20 % related to the dry weight of soil. The soil samples were mixed with the contaminant (MFO by hand and then left for 4 days for homogeneity. A series of laboratory tests are conducted on both natural and artificially contaminated soil samples to measure the effects of medium fuel oil on the chemical, physical and mechanical properties of soil samples. The results of tests showed that the medium fuel oil has significant impacts on some properties of soil and slight effects on the others. Increasing the percentage of contaminant causes a slight decrease in the liquid limit and particle size distribution; on the other hand, it causes a considerable increase in the consolidation parameters and decrease in shear strength parameters. Also, there is a slight change in the chemical composition of soil samples.

  16. Influence of physical and chemical properties of different soil types on optimal soil moisture for tillage

    Directory of Open Access Journals (Sweden)

    Vladimir Zebec

    2017-01-01

    Full Text Available Soil plasticity is the area of soil consistency, i.e. it represents a change in soil condition due to different soil moisture influenced by external forces activity. Consistency determines soil resistance in tillage, therefore, the aim of the research was to determine the optimum soil moisture condition for tillage and the influence of the chemical and physical properties of the arable land horizons on the soil plasticity on three different types of soil (fluvisol, luvisol and humic glaysol. Statistically significant differences were found between all examined soil types, such as the content of clay particles, the density of packaging and the actual and substitution acidity, the cation exchange capacity and the content of calcium. There were also statistically significant differences between the examined types of soil for the plasticity limit, liquid limit and the plasticity index. The average established value of plasticity limit as an important element for determining the optimal moment of soil tillage was 18.9% mass on fluvisol, 24.0% mass on luvisol and 28.6% mass on humic glaysol. Very significant positive direction correlation with plasticity limits was shown by organic matter, clay, fine silt, magnesium, sodium and calcium, while very significant negative direction correlation was shown by hydrolytic acidity, coarse sand, fine sand and coarse silt. Created regression models can estimate the optimal soil moisture condition for soil cultivation based on the basic soil properties. The model precision is significantly increased by introducing a greater number of agrochemical and agrophysical soil properties, and the additional precision of the model can be increased by soil type data.

  17. Sorption of samarium in soils: influence of soil properties and Sm concentration

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez-Guinart, Oriol; Salaberria, Aitor; Rigol, Anna; Vidal, Miquel [Analytical Chemistry department, Faculty of Chemistry, University of Barcelona, Marti i Franques 1-11, 08028, Barcelona (Spain)

    2014-07-01

    Due to the fact that barriers of Deep Geological Repositories (DGR) may lose efficiency before the radioisotopes present in the High Level Radioactive Waste (HLRW) completely decay, it is possible that, in the long-term, radioactive leachates may escape from the DGR and reach the soil and water compartments in the biosphere. Therefore, it is required to examine the interaction and mobility of radionuclides present in the HLRW, or their chemical analogues, to predict the impact of their eventual incorporation in the biosphere and to assess the derived risk. Although relevant data have been recently obtained for a few radionuclides in soils, there are still some important gaps for some radionuclides, such us for samarium (Sm). Sm is a lanthanide that, besides being considered as a natural analogue of actinides, may also be present in HLRW in the form of the radioactive isotope {sup 151}Sm. The main objective of this work was to obtain sorption data (K{sub d}) of {sup 151}Sm gathered from a set of soil samples physicochemical fully-characterized (pH, texture, cationic exchange capacity, soil solution cationic composition, organic matter, carbonate and metallic oxides content, etc.). Additionally, as an alternative for testing sorption capacity of radionuclides in soils is the use of the corresponding stable isotope or a chemical analogue, the influence of Sm concentration was also checked. To evaluate {sup 151}Sm sorption, batch assays were carried out for each soil sample, which consisted in a pre-equilibration step of 2 g of each soil with 50 ml of double deionised water, and a subsequent equilibration step with the same solution, but labelled with {sup 151}Sm. The activity of {sup 151}Sm in initial and final solutions was measured by liquid scintillation and K{sub d} ({sup 151}Sm) data were calculated. The reversibly sorbed fraction was estimated by the application of a single extraction test, with double deionised water, to soil residues coming from the previous

  18. Long-Term Effects of Legacy Copper Contamination on Microbial Activity and Soil Physical Properties

    DEFF Research Database (Denmark)

    Arthur, Emmanuel; Møldrup, Per; Holmstrup, Martin

    Soils heavily contaminated with copper (Cu) are considered unsuitable for agricultural use due to adverse impacts on microbial activity, soil physical properties, and direct toxicity to crops. This study investigated effects of Cu pollution from timber preservation activities between 1911 and 1924...... on soil micro-organisms and subsequent effects on physical properties of a sandy loam soil. Tillage operations over the last 70 years have caused spreading of the initially localized contamination and have created a Cu concentration gradient from 20 to 3800 mg kg-1 across an agricultural field in Hygum......, Denmark. Soil samples obtained from the fallow field were used to determine total microbial activity using fluorescein diacetate and dehydrogenase assays. The physical properties measured included water-dispersible clay, bulk density, air permeability and air-filled porosity. Significant differences...

  19. Behaviour of oxyfluorfen in soils amended with edaphic biostimulants/biofertilizers obtained from sewage sludge and chicken feathers. Effects on soil biological properties.

    Science.gov (United States)

    Rodríguez-Morgado, Bruno; Gómez, Isidoro; Parrado, Juan; Tejada, Manuel

    2014-09-01

    We studied the behaviour of oxyfluorfen herbicide at a rate of 4 l ha(-1) on biological properties of a Calcaric Regosol amended with two edaphic biostimulants/biofertilizers (SS, derived from sewage sludge; and CF, derived from chicken feathers). Oxyfluorfen was surface broadcast on 11 March 2013. Two days after application of oxyfluorfen to soil, both biostimulants/biofertilizers (BS) were also applied to the soil. An unamended soil without oxyfluorfen was used as control. For 2, 4, 7, 9, 20, 30, 60, 90 and 120 days of the application of herbicide to the soil and for each treatment, the soil dehydrogenase, urease, β-glucosidase and phosphatase activities were measured. For 2, 7, 30 and 120 days of the application of herbicide to the soil and for each treatment, soil microbial community was determined. The application of both BS to soil without the herbicide increased the enzymatic activities and soil biodiversity, mainly at 7 days of beginning the experiment. However, this stimulation was higher in the soil amended with SS than for CF. The application of herbicide in organic-amended soils decreased the inhibition of soil enzymatic activities and soil biodiversity. Possibly, the low-molecular-weight protein content easily assimilated by soil microorganisms is responsible for less inhibition of these soil biological properties.

  20. Soil biochemical properties of grassland ecosystems under anthropogenic emission of nitrogen compounds

    Science.gov (United States)

    Kudrevatykh, Irina; Ivashchenko, Kristina; Ananyeva, Nadezhda

    2016-04-01

    Inflow of pollutants in terrestrial ecosystems nowadays increases dramatically, that might be led to disturbance of natural biogeochemical cycles and landscapes structure. Production of nitrogen fertilizers is one of the air pollution sources, namely by nitrogen compounds (NH4+, NO3-, NO2-). Air pollution by nitrogen compounds of terrestrial ecosystems might be affected on soil biochemical properties, which results increasing mineral nitrogen content in soil, changing soil P/N and Al/Ca ratios, and, finally, the deterioration of soil microbial community functioning. The research is focused on the assessment of anthropogenic emission of nitrogen compounds on soil properties of grassland ecosystems in European Russia. Soil samples (Voronic Chernozem Pachic, upper 10 cm mineral layer, totally 10) were taken from grassland ecosystem: near (5-10 m) nitrogen fertilizer factory (NFF), and far from it (20-30 km, served as a control) in Tula region. In soil samples the NH4+ and NO3- (Kudeyarov's photocolorimetric method), P, Ca, Al (X-ray fluorescence method) contents were measured. Soil microbial biomass carbon (Cmic) was analyzed by substrate-induced respiration method. Soil microbial respiration (MR) was assessed by CO2 rate production. Soil microbial metabolic quotient (qCO2) was calculated as MR/Cmic ratio. Near NFF the soil ammonium and nitrate nitrogen contents were a strongly varied, variation coefficient (CV) was 42 and 86This study was supported by Russian Foundation of Basic Research Grant No. 14-04-00098, 15-44-03220, 15-04-00915.

  1. Effects of pig slurry application on soil physical and chemical properties and glyphosate mobility

    Directory of Open Access Journals (Sweden)

    Daniela Aparecida de Oliveira

    2014-10-01

    Full Text Available Pig slurry applied to soil at different rates may affect soil properties and the mobility of chemical compounds within the soil. The purpose of this study was to evaluate the effects of rates of pig slurry application in agricultural areas on soil physical and chemical properties and on the mobility of glyphosate through the soil profile. The study was carried out in the 12th year of an experiment with pig slurry applied at rates of 0 (control, 50, 100 and 200 m³ ha-1 yr-1 on a Latossolo Vermelho distrófico (Hapludox soil. In the control, the quantities of P and K removed by harvested grains were replaced in the next crop cycle. Soil physical properties (bulk density, porosity, texture, and saturated hydraulic conductivity and chemical properties (organic matter, pH, extractable P, and exchangeable K were measured. Soil solution samples were collected at depths of 20, 40 and 80 cm using suction lysimeters, and glyphosate concentrations were measured over a 60-day period after slurry application. Soil physical and chemical properties were little affected by the pig slurry applications, but soil pH was reduced and P levels increased in the surface layers. In turn, K levels were increased in sub-surface layers. Glyphosate concentrations tended to decrease over time but were not affected by pig slurry application. The concentrations of glyphosate found in different depths show that the pratice of this application in agricultural soils has the potential for contamination of groundwater, especially when the water table is the surface and heavy rains occur immediately after application.

  2. Variability of the soil-to-plant radiocaesium transfer factor for Japanese soils predicted with soil and plant properties.

    Science.gov (United States)

    Uematsu, Shinichiro; Vandenhove, Hildegarde; Sweeck, Lieve; Van Hees, May; Wannijn, Jean; Smolders, Erik

    2016-03-01

    Food chain contamination with radiocaesium (RCs) in the aftermath of the Fukushima accident calls for an analysis of the specific factors that control the RCs transfer. Here, soil-to-plant transfer factors (TF) of RCs for grass were predicted from the potassium concentration in soil solution (mK) and the Radiocaesium Interception Potential (RIP) of the soil using existing mechanistic models. The mK and RIP were (a) either measured for 37 topsoils collected from the Fukushima accident affected area or (b) predicted from the soil clay content and the soil exchangeable potassium content using the models that had been calibrated for European soils. An average ammonium concentration was used throughout in the prediction. The measured RIP ranged 14-fold and measured mK varied 37-fold among the soils. The measured RIP was lower than the RIP predicted from the soil clay content likely due to the lower content of weathered micas in the clay fraction of Japanese soils. Also the measured mK was lower than that predicted. As a result, the predicted TFs relying on the measured RIP and mK were, on average, about 22-fold larger than the TFs predicted using the European calibrated models. The geometric mean of the measured TFs for grass in the affected area (N = 82) was in the middle of both. The TFs were poorly related to soil classification classes, likely because soil fertility (mK) was obscuring the effects of the soil classification related to the soil mineralogy (RIP). This study suggests that, on average, Japanese soils are more vulnerable than European soils at equal soil clay and exchangeable K content. The affected regions will be targeted for refined model validation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Laboratory analysis of soil hydraulic properties of TA-49 soil samples. Volume I: Report summary

    International Nuclear Information System (INIS)

    1995-04-01

    The Hydrologic Testing Laboratory at Daniel B. Stephens ampersand Associates, Inc. (DBS ampersand A) has completed laboratory tests on TA-49 soil samples as specified by Mr. Daniel A. James and summarized in Table 1. Tables 2 through 12 give the results of the specified analyses. Raw laboratory data and graphical plots of data (where appropriate) are contained in Appendices A through K. Appendix L lists the methods used in these analyses. A detailed description of each method is available upon request. Thermal properties were calculated using methods reviewed by Campbell and covered in more detail in Appendix K. Typically, soil thermal conductivities are determined using empirical fitting parameters (five in this case), Some assumptions are also made in the equations used to reduce the raw data. In addition to the requested thermal property measurements, calculated values are also presented as the best available internal check on data quality. For both thermal conductivities and specific heats, calculated and measured values are consistent and the functions often cross. Interestingly, measured thermal conductivities tend to be higher than calculated thermal conductivities around typically encountered in situ moisture contents (±5 percent). While we do not venture an explanation of the difference, sensitivity testing of any problem requiring nonisothermal modeling across this range is in order

  4. Spatial variability of physical properties of tropical soil

    International Nuclear Information System (INIS)

    Reichardt, K.; Libardi, P.L.; Queiroz, S.V.; Grohmann, F.

    1976-04-01

    A basic study with objectives of improving the use of soil and water resources under a particular condition and of developing means for controlling the dynamics of soil-water movement are presented. Special emphasis is given to the variability in space of geometric soil properties such as bulk density, particle density and texture in order to make it possible to define representative means which ideed will be usable to describe the movement of water and of salt in the entire field

  5. Effect of land use change on soil properties and functions

    Science.gov (United States)

    Tonutare, Tonu; Kõlli, Raimo; Köster, Tiina; Rannik, Kaire; Szajdak, Lech; Shanskiy, Merrit

    2014-05-01

    For good base of sustainable land management and ecologically sound protection of soils are researches on soil properties and functioning. Ecosystem approach to soil properties and functioning is equally important in both natural and cultivated land use conditions. Comparative analysis of natural and agro-ecosystems formed on similar soil types enables to elucidate principal changes caused by land use change (LUC) and to elaborate the best land use practices for local pedo-ecological conditions. Taken for actual analysis mineral soils' catena - rendzina → brown soils → pseudopodzolic soils → gley-podzols - represent ca 1/3 of total area of Estonian normal mineral soils. All soils of this catena differ substantially each from other by calcareousness, acidity, nutrition conditions, fabric and humus cover type. This catena (representative to Estonian pedo-ecological conditions) starts with drought-prone calcareous soils. Brown (distributed in northern and central Estonia) and pseudopodzolic soils (in southern Estonia) are the most broadly acknowledged for agricultural use medium-textured high-quality automorphic soils. Dispersedly distributed gley-podzols are permanently wet and strongly acid, low-productivity sandy soils. In presentation four complex functions of soils are treated: (1) being a suitable soil environment for plant cover productivity (expressed by annual increment, Mg ha-1 yr-1); (2) forming adequate conditions for decomposition, transformation and conversion of fresh falling litter (characterized by humus cover type); (3) deposition of humus, individual organic compounds, plant nutrition elements, air and water, and (4) forming (bio)chemically variegated active space for soil type specific edaphon. Capacity of soil cover as depositor (3) depends on it thickness, texture, calcareousness and moisture conditions. Biological activity of soil (4) is determined by fresh organic matter influx, quality and quantity of biochemical substances and humus

  6. Measuring lateral saturated soil hydraulic conductivity at different spatial scales

    Science.gov (United States)

    Di Prima, Simone; Marrosu, Roberto; Pirastru, Mario; Niedda, Marcello

    2017-04-01

    Among the soil hydraulic properties, saturated soil hydraulic conductivity, Ks, is particularly important since it controls many hydrological processes. Knowledge of this soil property allows estimation of dynamic indicators of the soil's ability to transmit water down to the root zone. Such dynamic indicators are valuable tools to quantify land degradation and developing 'best management' land use practice (Castellini et al., 2016; Iovino et al., 2016). In hillslopes, lateral saturated soil hydraulic conductivity, Ks,l, is a key factor since it controls subsurface flow. However, Ks,l data collected by point-scale measurements, including infiltrations tests, could be unusable for interpreting field hydrological processes and particularly subsurface flow in hillslopes. Therefore, they are generally not representative of subsurface processes at hillslope-scale due mainly to soil heterogeneities and the unknown total extent and connectivity of macropore network in the porous medium. On the other hand, large scale Ks,l measurements, which allow to average soil heterogeneities, are difficult and costly, thus remain rare. Reliable Ks,l values should be measured on a soil volume similar to the representative elementary volume (REV) in order to incorporate the natural heterogeneity of the soil. However, the REV may be considered site-specific since it is expected to increase for soils with macropores (Brooks et al., 2004). In this study, laboratory and in-situ Ks,l values are compared in order to detect the dependency Ks,l from the spatial scale of investigation. The research was carried out at a hillslope located in the Baratz Lake watershed, in northwest Sardinia, Italy, characterized by degraded vegetation (grassland established after fire or clearing of the maquis). The experimental area is about 60 m long, with an extent of approximately 2000 m2, and a mean slope of 30%. The soil depth is about 35 to 45 cm. The parent material is a very dense grayish, altered

  7. Predicting molybdenum toxicity to higher plants: Influence of soil properties

    Energy Technology Data Exchange (ETDEWEB)

    McGrath, S.P., E-mail: steve.mcgrath@bbsrc.ac.u [Soil Science Department, Centre for Soils and Ecosystems Functions, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ (United Kingdom); Mico, C. [Soil Science Department, Centre for Soils and Ecosystems Functions, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ (United Kingdom); Curdy, R. [Laboratory for Environmental Biotechnology (LBE), Swiss Federal Institute of Technology Lausanne (EPFL) Station 6 CH, 1015 Lausanne (Switzerland); Zhao, F.J. [Soil Science Department, Centre for Soils and Ecosystems Functions, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ (United Kingdom)

    2010-10-15

    The effect of soil properties on the toxicity of molybdenum (Mo) to four plant species was investigated. Soil organic carbon or ammonium-oxalate extractable Fe oxides were found to be the best predictors of the 50% effective dose (ED{sub 50}) of Mo in different soils, explaining > 65% of the variance in ED{sub 50} for four species except for ryegrass (26-38%). Molybdenum concentrations in soil solution and consequently plant uptake were increased when soil pH was artificially raised because sorption of Mo to amorphous oxides is greatly reduced at high pH. The addition of sulphate significantly decreased Mo uptake by oilseed rape. For risk assessment, we suggest that Mo toxicity values for plants should be normalised using soil amorphous iron oxide concentrations. - Amorphous iron oxides or organic carbon were found to be the best predictors of the toxicity threshold values of Mo to higher plants on different soils.

  8. Predicting molybdenum toxicity to higher plants: Influence of soil properties

    International Nuclear Information System (INIS)

    McGrath, S.P.; Mico, C.; Curdy, R.; Zhao, F.J.

    2010-01-01

    The effect of soil properties on the toxicity of molybdenum (Mo) to four plant species was investigated. Soil organic carbon or ammonium-oxalate extractable Fe oxides were found to be the best predictors of the 50% effective dose (ED 50 ) of Mo in different soils, explaining > 65% of the variance in ED 50 for four species except for ryegrass (26-38%). Molybdenum concentrations in soil solution and consequently plant uptake were increased when soil pH was artificially raised because sorption of Mo to amorphous oxides is greatly reduced at high pH. The addition of sulphate significantly decreased Mo uptake by oilseed rape. For risk assessment, we suggest that Mo toxicity values for plants should be normalised using soil amorphous iron oxide concentrations. - Amorphous iron oxides or organic carbon were found to be the best predictors of the toxicity threshold values of Mo to higher plants on different soils.

  9. Natural radionuclides in soils - relation between soil properties and the activities

    International Nuclear Information System (INIS)

    Fujiyoshi, Ryoko; Nakayama, Masashi; Sawamura, Sadashi

    2000-01-01

    Vertical profiles of natural radionuclides (K-40 and Ra-226) have been investigated in a soil core with 8 m in depth to elucidate its relation to the bed rock activity and to several soil properties. Pattern of the Ra-226 activity with soil depth suggests inhomogeneity of this nuclide during the accumulating process. Radiometric sorption experiments with Pb-210 as a tracer gave the result that almost all Pb(II) in the soil solution disappeared to be sorbed to the soil components

  10. Soil physical and hydraulic properties modification under Arachis ...

    African Journals Online (AJOL)

    A field study was carried out to determine the effects of 3 plant densities (33333, 66667 and 83333 plants/ha)on soil properties and water loss through evaporation from soils under 2 cultivars of Arachis hypogaeaL. (SAMNUT 10 and SAMNUT 21) and Arachis pintoi(PINTOI) in Ibadan, south western Nigeria. The experiment ...

  11. Effect of Cassava Processing Effluent on Soil Properties, Growth and ...

    African Journals Online (AJOL)

    A study, comprising a survey, greenhouse and field experiments was conducted to examine the effect of Cassava Processing Effluent (CPE) on soil chemical properties, maize growth performances and grain yield. In the survey, soil samples were taken (0-15 and 15 – 30cm) of CPE contaminated and non contaminated ...

  12. Mechanical properties of millet husk ash bitumen stabilized soil block

    African Journals Online (AJOL)

    This study presents an investigation into the improvement of strength and durability properties of lateritic soil blocks using Millet Husk Ash (MHA) and Bitumen as additives so as to reduce its high cost and find alternative disposal method for agricultural waste. The lateritic soil samples were selected and treated with 0%, ...

  13. Effect of animal manures on selected soil chemical properties (1 ...

    African Journals Online (AJOL)

    The effects of animal manures on selected soil properties were studied in the laboratory. Manures of Rabbit (RBM), Swine (SWM), Poultry (POM), Goat, (GTM) and Cow (COM) were added at 10, 20, 30 and 40 t/ha to an acidic Ultisol. The amended soils were incubated at 70% water holding capacity for 3 weeks.

  14. Mechanical Properties of Millet Husk Ash Bitumen Stabilized Soil ...

    African Journals Online (AJOL)

    Akorede

    lateritic soil blocks using Millet Husk Ash (MHA) and Bitumen as additives so as to reduce its high cost and find ... eliminating the need for air-conditioning and are warm during the cold ... The mix properties were used in producing soil bricks of ...

  15. Sensor data fusion to predict multiple soil properties

    NARCIS (Netherlands)

    Mahmood, H.S.; Hoogmoed, W.B.; Henten, van E.J.

    2012-01-01

    The accuracy of a single sensor is often low because all proximal soil sensors respond to more than one soil property of interest. Sensor data fusion can potentially overcome this inability of a single sensor and can best extract useful and complementary information from multiple sensors or sources.

  16. Evaluation Of Management Properties Of Wetland Soils Of Akwa ...

    African Journals Online (AJOL)

    Evaluation Of Management Properties Of Wetland Soils Of Akwa Ibom State, Nigeria For Sustainable Crop Production. ... Organic matter content values were high with mean of 12.59, 60.01, and 3.20 percent for Inland valley, Flood plain and mangrove soils respectively. Effective cation exchange capacity (ECEC) was below ...

  17. A selection of sensing techniques for mapping soil hydraulic properties

    NARCIS (Netherlands)

    Knotters, M.; Egmond, van F.M.; Bakker, G.; Walvoort, D.J.J.; Brouwer, F.

    2017-01-01

    Data on soil hydraulic properties are needed as input for many models, such as models to predict unsaturated water movement and crop growth, and models to predict leaching of nutrients and pesticides to groundwater. The soil physics database of the Netherlands shows several lacunae, and a

  18. Acoustic Determination of Near-Surface Soil Properties

    Science.gov (United States)

    2008-12-01

    requiring geostatistical analysis, while nearby others are spatially independent. In studies involving many different soil properties and chemistry ...Am 116(6), p. 3354-3369. Kravchenko, N., C.W. Boast, D.G. Bullock, 1991. Fractal analysis of soil spatial variability. Agronomy Journal 91

  19. Effect of biosolids application on soil chemical properties and uptake ...

    African Journals Online (AJOL)

    Effect of biosolids application on soil chemical properties and uptake of some heavy metals by Cercis siliquastrum. ... and municipal solid waste compost (50% CM + 50% MC) at three levels of 0, 2.5 and 5 kg/shrub and three replicates in calcareous sandy loam soil at the botanical garden of Mobarekeh steel company.

  20. Soil properties influence kinetics of soil acid phosphatase in response to arsenic toxicity.

    Science.gov (United States)

    Wang, Ziquan; Tan, Xiangping; Lu, Guannan; Liu, Yanju; Naidu, Ravi; He, Wenxiang

    2018-01-01

    Soil phosphatase, which plays an important role in phosphorus cycling, is strongly inhibited by Arsenic (As). However, the inhibition mechanism in kinetics is not adequately investigated. In this study, we investigated the kinetic characteristics of soil acid phosphatase (ACP) in 14 soils with varied properties, and also explored how kinetic properties of soil ACP changed with different spiked As concentrations. The results showed that the Michaelis constant (K m ) and maximum reaction velocity (V max ) values of soil ACP ranged from 1.18 to 3.77mM and 0.025-0.133mMh -1 in uncontaminated soils. The kinetic parameters of soil ACP in different soils changed differently with As contamination. The K m remained unchanged and V max decreased with increase of As concentration in most acid and neutral soils, indicating a noncompetitive inhibition mechanism. However, in alkaline soils, the K m increased linearly and V max decreased with increase of As concentration, indicating a mixed inhibition mechanism that include competitive and noncompetitive. The competitive inhibition constant (K ic ) and noncompetitive inhibition constant (K iu ) varied among soils and ranged from 0.38 to 3.65mM and 0.84-7.43mM respectively. The inhibitory effect of As on soil ACP was mostly affected by soil organic matter and cation exchange capacity. Those factors influenced the combination of As with enzyme, which resulted in a difference of As toxicity to soil ACP. Catalytic efficiency (V max /K m ) of soil ACP was a sensitive kinetic parameter to assess the ecological risks of soil As contamination. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Measured and simulated soil water evaporation from four Great Plains soils

    Science.gov (United States)

    The amount of soil water lost during stage one and stage two soil water evaporation is of interest to crop water use modelers. The ratio of measured soil surface temperature (Ts) to air temperature (Ta) was tested as a signal for the transition in soil water evaporation from stage one to stage two d...

  2. Long Term Effects of Poultry Litter on Soil Physical and Chemical Properties in Cotton Plots

    Science.gov (United States)

    Surrency, J.; Tsegaye, T.; Coleman, T.; Fahsi, A.; Reddy, C.

    1998-01-01

    Poultry litter and compost can alter the moisture holding capacity of a soil. These organic materials can also increase the nutrient status of a soil during the decomposition process by microbial actions. The objective of this study was to evaluate the effect of poultry litter and compost on the dielectric constant and moisture holding capacity of soil. The Delta-T theta-probe was used to measure volumetric soil water content and the apparent dielectric constant of the upper 6-cm of the soil profile. Soil texture, pH, and organic matter were also determined for each plot. Results of these analyses indicated that the pH of the soil ranged from 6.4 to 7.7 and the volumetric soil moisture content ranged from 0.06 to 0.18 cu m/cu m for the upper 6-cm of the soil profile. The effect of poultry litter and compost on soil properties resulted in an increase in the volumetric moisture content and dielectric constant of the soil due to the improvement of the soil structure.

  3. Relations between soil hydraulic properties and burn severity

    NARCIS (Netherlands)

    Moody, J.A.; Ebel, B.A.; Stoof, C.R.; Nyman, P.; Martin, D.A.; McKinley, R.

    2016-01-01

    Wildfire can affect soil hydraulic properties, often resulting in reduced infiltration. The magnitude of change in infiltration varies depending on the burn severity. Quantitative approaches to link burn severity with changes in infiltration are lacking. This study uses controlled laboratory

  4. Preliminary study of soil permeability properties using principal component analysis

    Science.gov (United States)

    Yulianti, M.; Sudriani, Y.; Rustini, H. A.

    2018-02-01

    Soil permeability measurement is undoubtedly important in carrying out soil-water research such as rainfall-runoff modelling, irrigation water distribution systems, etc. It is also known that acquiring reliable soil permeability data is rather laborious, time-consuming, and costly. Therefore, it is desirable to develop the prediction model. Several studies of empirical equations for predicting permeability have been undertaken by many researchers. These studies derived the models from areas which soil characteristics are different from Indonesian soil, which suggest a possibility that these permeability models are site-specific. The purpose of this study is to identify which soil parameters correspond strongly to soil permeability and propose a preliminary model for permeability prediction. Principal component analysis (PCA) was applied to 16 parameters analysed from 37 sites consist of 91 samples obtained from Batanghari Watershed. Findings indicated five variables that have strong correlation with soil permeability, and we recommend a preliminary permeability model, which is potential for further development.

  5. Combining phytoextraction and biochar addition improves soil biochemical properties in a soil contaminated with Cd.

    Science.gov (United States)

    Lu, Huanping; Li, Zhian; Fu, Shenglei; Méndez, Ana; Gascó, Gabriel; Paz-Ferreiro, Jorge

    2015-01-01

    The main goal of phytoremediation is to improve ecosystem functioning. Soil biochemical properties are considered as effective indicators of soil quality and are sensitive to various environmental stresses, including heavy metal contamination. The biochemical response in a soil contaminated with cadmium was tested after several treatments aimed to reduce heavy metal availability including liming, biochar addition and phytoextraction using Amaranthus tricolor L. Two biochars were added to the soil: eucalyptus pyrolysed at 600 °C (EB) and poultry litter at 400 °C (PLB). Two liming treatments were chosen with the aim of bringing soil pH to the same values as in the treatments EB and PLB. The properties studied included soil microbial biomass C, soil respiration and the activities of invertase, β-glucosidase, β-glucosaminidase, urease and phosphomonoesterase. Both phytoremediation and biochar addition improved soil biochemical properties, although results were enzyme specific. For biochar addition these changes were partly, but not exclusively, mediated by alterations in soil pH. A careful choice of biochar must be undertaken to optimize the remediation process from the point of view of metal phytoextraction and soil biological activity. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Using soil properties to predict in vivo bioavailability of lead in soils.

    Science.gov (United States)

    Wijayawardena, M A Ayanka; Naidu, Ravi; Megharaj, Mallavarapu; Lamb, Dane; Thavamani, Palanisami; Kuchel, Tim

    2015-11-01

    Soil plays a significant role in controlling the potential bioavailability of contaminants in the environment. In this study, eleven soils were used to investigate the relationship between soil properties and relative bioavailability (RB) of lead (Pb). To minimise the effect of source of Pb on in vivo bioavailability, uncontaminated study soils were spiked with 1500 mg Pb/kg soil and aged for 10-12 months prior to investigating the relationships between soil properties and in vivo RB of Pb using swine model. The biological responses to oral administration of Pb in aqueous phase or as spiked soils were compared by applying a two-compartment pharmacokinetic model to blood Pb concentration. The study revealed that RB of Pb from aged soils ranged from 30±9% to 83±7%. The very different RB of Pb in these soils was attributed to variations in the soils' physico-chemical properties. This was established using sorption studies showing: firstly, Freundlich partition coefficients that ranged from 21 to 234; and secondly, a strongly significant (R(2)=0.94, Psoils. To the best of our knowledge, this is the first such model derived using sorption partition coefficient to predict the relative bioavailability of Pb. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Magnetic and Geochemical Properties of Andic Soils from the Massif Central, France

    Science.gov (United States)

    Grison, H.; Petrovsky, E.; Dlouha, S.; Kapicka, A.

    2014-12-01

    Ferrimagnetic iron oxides are the key magnetic minerals responsible for enhancement of the magnetic susceptibility in soils. Soils with andic properties contain high amount of Fe-oxides, but only few attempts were made to characterize these soils using magnetic methods. Magnetic susceptibility is in particular suitable for its sensitivity and fast measurement; the presence of Fe-oxides can be easily identified directly in the field. The aim of our study is to describe main magnetic and geochemical properties of soils rich in Fe oxides derived from strongly magnetic volcanic basement. The studied sites are located at the basalt parent rock formed during Pleistocene, Pliocene and Miocene. Investigated soils are exposed to the mountainous climate with the perudic soil moisture regime and cryic temperature soil regime. Seven basalt soil profiles with typical andic properties were analyzed down to parent rock by a set of magnetic and geochemical methods. The magnetic susceptibility was measured in situ and in laboratory using the Bartington MS2D and AGICO MFK1. Its temperature dependence was measured in order to assess phase transformations of magnetic minerals using the KLY4. Magnetic data were completed by the hysteresis, IRM and DCD measurements using ADE EV9 VSM. Geochemical data include soil reaction (pH), organic carbon, cations exchange capacity, and extractable iron and aluminium in the soil extracted by a dithionite-citrate, acid-ammonium oxalate and a pyrophosphate solution. Scanning electron microscopy was done for top/sub-soil and rock samples. Geochemical soil properties reflecting iron oxide stability correlate well with mass-specific magnetic susceptibility. Well pronounced relationship was observed between magnetic grain size, precipitation and soil pH, second group is reflecting concentration of feri-magnetic particles and age of parent rock, and the third group reflects degree of weathering and the thermomagnetic indices expressing changes in magneto

  8. Influence of soil pedological properties on termite mound stability

    OpenAIRE

    Jouquet, Pascal; Guilleux, N.; Caner, L.; Chintakunta, S.; Ameline, M.; Shanbhag, R. R.

    2016-01-01

    This study investigated the influence of soil properties on the density and shape of epigeous fungus-growing termite nests in a dry deciduous forest in Karnataka, India. In this environment, Odontotermes obesus produces cathedral shaped mounds. Their density, shape (height and volume) and soil physicochemical properties were analyzed in ferralsol and vertisol environments. No significant difference was observed in O. obesus mound density (n = 2.7 mound ha(-1) on average in the vertisol and fe...

  9. Effects of prescribed fires on soil properties: A review.

    Science.gov (United States)

    Alcañiz, M; Outeiro, L; Francos, M; Úbeda, X

    2018-02-01

    Soils constitute one of the most valuable resources on earth, especially because soil is renewable on human time scales. During the 20th century, a period marked by a widespread rural exodus and land abandonment, fire suppression policies were adopted facilitating the accumulation of fuel in forested areas, exacerbating the effects of wildfires, leading to severe degradation of soils. Prescribed fires emerged as an option for protecting forests and their soils from wildfires through the reduction of fuels levels. However such fires can serve other objectives, including stimulating the regeneration of a particular plant species, maintaining biological diversity or as a tool for recovering grasslands in encroached lands. This paper reviews studies examining the short- and long- term impacts of prescribed fires on the physical, chemical and biological soil properties; in so doing, it provides a summary of the benefits and drawbacks of this technique, to help determine if prescribed fires can be useful for managing the landscape. From the study conducted, we can affirm that prescribed fires affects soil properties but differ greatly depending on soil initial characteristics, vegetation or type of fire. Also, it is possible to see that soil's physical and biological properties are more strongly affected by prescribed fires than are its chemical properties. Finally, we conclude that prescribed fires clearly constitute a disturbance on the environment (positive, neutral or negative depending on the soil property studied), but most of the studies reviewed report a good recovery and their effects could be less pronounced than those of wildfires because of the limited soil heating and lower fire intensity and severity. Copyright © 2017. Published by Elsevier B.V.

  10. Assessing the influence of the rhizosphere on soil hydraulic properties using X-ray computed tomography and numerical modelling.

    Science.gov (United States)

    Daly, Keith R; Mooney, Sacha J; Bennett, Malcolm J; Crout, Neil M J; Roose, Tiina; Tracy, Saoirse R

    2015-04-01

    Understanding the dynamics of water distribution in soil is crucial for enhancing our knowledge of managing soil and water resources. The application of X-ray computed tomography (CT) to the plant and soil sciences is now well established. However, few studies have utilized the technique for visualizing water in soil pore spaces. Here this method is utilized to visualize the water in soil in situ and in three-dimensions at successive reductive matric potentials in bulk and rhizosphere soil. The measurements are combined with numerical modelling to determine the unsaturated hydraulic conductivity, providing a complete picture of the hydraulic properties of the soil. The technique was performed on soil cores that were sampled adjacent to established roots (rhizosphere soil) and from soil that had not been influenced by roots (bulk soil). A water release curve was obtained for the different soil types using measurements of their pore geometries derived from CT imaging and verified using conventional methods, such as pressure plates. The water, soil, and air phases from the images were segmented and quantified using image analysis. The water release characteristics obtained for the contrasting soils showed clear differences in hydraulic properties between rhizosphere and bulk soil, especially in clay soil. The data suggest that soils influenced by roots (rhizosphere soil) are less porous due to increased aggregation when compared with bulk soil. The information and insights obtained on the hydraulic properties of rhizosphere and bulk soil will enhance our understanding of rhizosphere biophysics and improve current water uptake models. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  11. Estimation of Corn Yield and Soil Nitrogen via Soil Electrical Conductivity Measurement Treated with Organic, Chemical and Biological Fertilizers

    Directory of Open Access Journals (Sweden)

    H. Khalilzade

    2016-02-01

    Full Text Available Introduction Around the world maize is the second crop with the most cultivated areas and amount of production, so as the most important strategic crop, have a special situation in policies, decision making, resources and inputs allocation. On the other side, negative environmental consequences of intensive consumption of agrochemicals resulted to change view concerning food production. One of the most important visions is sustainable production of enough food plus attention to social, economic and environmental aspects. Many researchers stated that the first step to achieve this goal is optimization and improvement of resources use efficiencies. According to little knowledge on relation between soil electrical conductivity and yield of maize, beside the environmental concerns about nitrogen consumption and need to replace chemical nitrogen by ecological inputs, this study designed and aimed to evaluate agroecological characteristics of corn and some soil characteristics as affected by application of organic and biological fertilizers under field conditions. Materials and Methods In order to probing the possibility of grain yield and soil nitrogen estimation via measurement of soil properties, a field experiment was conducted during growing season 2010 at Research Station, Ferdowsi University of Mashhad, Iran. A randomized complete block design (RCBD with three replications was used. Treatments included: 1- manure (30 ton ha-1, 2-vermicompost (10 ton ha-1, 3- nitroxin (containing Azotobacter sp. and Azospirillum sp., inoculation was done according to Kennedy et al., 4- nitrogen as urea (400 kg ha-1 and 5- control (without fertilizer. Studied traits were soil pH, soil EC, soil respiration rate, N content of soil and maize yield. Soil respiration rate was measured using equation 1: CO2= (V0- V× N×22 Equation 1 In which V0 is the volume of consumed acid for control treatment titration, V is of the volume of consumed acid for sample treatment

  12. Impact of temperature on the biological properties of soil

    Science.gov (United States)

    Borowik, Agata; Wyszkowska, Jadwiga

    2016-01-01

    The aim of the study was to determine the response of soil microorganisms and enzymes to the temperature of soil. The effect of the temperatures: 5, 10, 15, 20, and 25°C on the biological properties of soil was investigated under laboratory conditions. The study was performed using four different soils differing in their granulometric composition. It was found that 15°C was the optimal temperature for the development of microorganisms in soil. Typically, in the soil, the highest activity of dehydrogenases was observed at 10-15°C, catalase and acid phosphatase - at 15°C, alkaline phosphatase at 20°C, urease and β-glucosidase at 25°C. The highest colony development index for heterotrophic bacteria was recorded in soils incubated at 25°C, while for actinomycetes and fungi at 15°C. The incubation temperature of soil only slightly changed the ecophysiological variety of the investigated groups of microorganisms. Therefore, the observed climate changes might have a limited impact on the soil microbiological activity, because of the high ability of microorganisms to adopt. The response of soil microorganisms and enzymes was more dependent on the soil granulometric composition, organic carbon, and total nitrogen than on its temperature.

  13. Furfural and its biochar improve the general properties of a saline soil

    Science.gov (United States)

    Wu, Y.; Xu, G.; Shao, H. B.

    2014-07-01

    Organic materials (e.g., furfural residue) are generally believed to improve the physical and chemical properties of saline soils with low fertility. Recently, biochar has been received more attention as a possible measure to improve the carbon balance and improve soil quality in some degraded soils. However, little is known about their different amelioration of a sandy saline soil. In this study, 56 d incubation experiment was conducted to evaluate the influence of furfural and its biochar on the properties of saline soil. The results showed that both furfural and biochar greatly reduced pH, increased soil organic carbon (SOC) content and cation exchange capacity (CEC), and enhanced the available phosphorus (P) in the soil. Furfural is more efficient than biochar in reducing pH: 5% furfural lowered the soil pH by 0.5-0.8 (soil pH: 8.3-8.6), while 5% biochar decreased by 0.25-0.4 due to the loss of acidity in pyrolysis process. With respect to available P, furfural addition at a rate of 5% increased available P content by 4-6 times in comparison to 2-5 times with biochar application. In reducing soil exchangeable sodium percentage (ESP), biochar is slightly superior to furfural because soil ESP reduced by 51% and 43% with 5% furfural and 5% biochar at the end of incubation. In addition, no significant differences were observed between furfural and biochar about their capacity to retain N, P in leaching solution and to increase CEC in soil. These facts may be caused by the relatively short incubation time. In general, furfural and biochar exhibited a different effect depending on the property: furfural was more effective in decreasing pH and increasing available P, whereas biochar played a more important role in increasing SOC and reducing ESP of saline soil.

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

    Science.gov (United States)

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

    2016-04-01

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

  15. Quantifying the Effects of Biofilm on the Hydraulic Properties of Unsaturated Soils

    Science.gov (United States)

    Volk, E.; Iden, S.; Furman, A.; Durner, W.; Rosenzweig, R.

    2017-12-01

    Quantifying the effects of biofilms on hydraulic properties of unsaturated soils is necessary for predicting water and solute flow in soil with extensive microbial presence. This can be relevant to bioremediation processes, soil aquifer treatment and effluent irrigation. Previous works showed a reduction in the hydraulic conductivity and an increase in water content due to the addition of biofilm analogue materials. The objective of this research is to quantify soil hydraulic properties of unsaturated soil (water retention and hydraulic conductivity) using real soil biofilm. In this work, Hamra soil was incubated with Luria Broth (LB) and biofilm-producing bacteria (Pseudomonas Putida F1). Hydraulic conductivity and water retention were measured by the evaporation method, Dewpoint method and a constant head permeameter. Biofilm was quantified using viable counts and the deficit of TOC. The results show that the presence of biofilms increases soil retention in the `dry' range of the curve and reduces the hydraulic conductivity (see figure). This research shows that biofilms may have a non-negligible effect on flow and transport in unsaturated soils. These findings contribute to modeling water flow in biofilm amended soil.

  16. Effects of traffic-induced soil compaction on crop growth and soil properties

    Science.gov (United States)

    Baibay, Amélia; Ren, Lidong; D'Hose, Tommy; De Pue, Jan; Ruysschaert, Greet; Cornelis, Wim

    2017-04-01

    Traffic-induced soil compaction on arable soils constitutes a major threat for agricultural productivity and the environmental quality of the soil, water and atmosphere. The objective of this work is to evaluate a set of prevention strategies for agricultural traffic under real farming conditions. To that end, a one-pass traffic experiment was conducted near Ghent, Belgium in winter 2015 on a sandy loam (haplic Luvisol; 43% sand, 47% silt, 10% clay). Winter rye (Secale cereale L.), which promotes the removal of residual soil nitrogen and thus reduces the potential for nitrogen leaching, was sown as cover crop using different tractor and weather settings on different field lanes: dry (D, 0.16 m3 m-3) or wet (W, 0.20-0.23 m3 m-3) conditions, normal (N, 65 cm width, axle load 8520 kg) or wide (W, 90 cm width, axle load 8520 kg) tires and high (HP, 1.4 bars for N, 1.0 bar for W) or low (LP, 1.0 bar for N, 0.5 bar for W) inflation pressure. Subsequently, crop biomass, root density and a set of hydrophysical properties (penetration resistance, saturated hydraulic conductivity and water retention at 15, 35 and 55 cm depth) were measured. Bulk density, soil quality indicators (such as air capacity) and the pore size distribution were also calculated. Results showed significant biomass reduction (p crop growth, worse under wet conditions, but the choice of tires did not prove to have an effect. Observations on the hydrophysical properties were more mitigated, as expected: distinct differences are primarily found under controlled lab conditions or after several passes. Moreover, high moisture conditions could not be obtained for the wet experiment, which never exceeded field capacity, conceived as threshold. Nevertheless, penetration resistance profiles indicated a plough pan about 40 cm depth, witness of previous agricultural operations on the field, and high values (3.5 to 4 MPa) were found in the subsoil too. Moreover, bulk densities were higher for all treatments (up to

  17. Radiometric characterization of six soils in the microwave X-range through complex permittivity measurements

    International Nuclear Information System (INIS)

    Palme, U.W.

    1987-10-01

    Estimating and monitoring up-to-date soil moisture conditions over extensive areas through passive (or active) microwave remote sensing techniques requires the knowledge of the complex relative permittivity (ε r * ) in function of soil moisture. X-band measurements of ε r * for different moisture conditions were made in laboratory for soil samples of six important Soils (PV 2 , LV 3 , LR d , LE 1 , SAP and Sc). Using a theoretical model and computational programmes developed, these measurements allowed estimates of the emissive characteristics of the soils that would be expected with the X-Band Microwave Radiometer built at INPE. The results, new, for soils from tropical regions, showed that only the physical characteristics and properties of the soils are not sufficient to explain the behaviour of ε r * in function of soil moisture, indicating that the chemical and/or mineralogical properties of the soils do have an important contribution. The results also showed thast ε r * in function of soil moisture depends on soil class. (author) [pt

  18. Short-Term Changes in Physical and Chemical Properties of Soil Charcoal Support Enhanced Landscape Mobility

    Science.gov (United States)

    Pyle, Lacey A.; Magee, Kate L.; Gallagher, Morgan E.; Hockaday, William C.; Masiello, Caroline A.

    2017-11-01

    Charcoal is a major component of the stable soil organic carbon reservoir, and the physical and chemical properties of charcoal can sometimes significantly alter bulk soil properties (e.g., by increasing soil water holding capacity). However, our understanding of the residence time of soil charcoal remains uncertain, with old measured soil charcoal ages in apparent conflict with relatively short modeled and measured residence times. These discrepancies may exist because the fate of charcoal on the landscape is a function not just of its resistance to biological decomposition but also its physical mobility. Mobility may be important in controlling charcoal landscape residence time and may artificially inflate estimates of its degradability, but few studies have examined charcoal vulnerability to physical redistribution. Charcoal landscape redistribution is likely higher than other organic carbon fractions owing to charcoal's low bulk density, typically less than 1.0 g/cm3. Here we examine both the physical and chemical properties of soil and charcoal over a period of two years following a 2011 wildfire in Texas. We find little change in properties with time; however, we find evidence of enhanced mobility of charcoal relative to other forms of soil organic matter. These data add to a growing body of evidence that charcoal is preferentially eroded, offering another explanation for variations observed in its environmental residence times.

  19. Effects of Conventional and Conservation Tillage on Soil Hydraulic Properties of a Silty-loamy Soil

    DEFF Research Database (Denmark)

    Wahl, Niels Arne; Bens, O.; Buczko, U.

    2004-01-01

    Infiltration into soils is strongly correlated with macroporosity. Under agricultural land use, the properties of the macropore network are governed by the applied management and tillage system. On an experimental site with a silt loam soil partly under conventional and conservation tillage, the ......, conservation tillage could possibly offer a means to reduce surface runoff and flood generation in agricultural landscapes dominated by silty-loamy soils. d 2...

  20. Relationship between sugarcane rust severity and soil properties in louisiana.

    Science.gov (United States)

    Johnson, Richard M; Grisham, Michael P; Richard, Edward P

    2007-06-01

    ABSTRACT The extent of spatial and temporal variability of sugarcane rust (Puccinia melanocephala) infestation was related to variation in soil properties in five commercial fields of sugarcane (interspecific hybrids of Saccharum spp., cv. LCP 85-384) in southern Louisiana. Sugarcane fields were grid-soil sampled at several intensities and rust ratings were collected at each point over 6 to 7 weeks. Soil properties exhibited significant variability (coefficients of variation = 9 to 70.1%) and were spatially correlated in 39 of 40 cases with a range of spatial correlation varying from 39 to 201 m. Rust ratings were spatially correlated in 32 of 33 cases, with a range varying from 29 to 241 m. Rust ratings were correlated with several soil properties, most notably soil phosphorus (r = 0.40 to 0.81) and soil sulfur (r = 0.36 to 0.68). Multiple linear regression analysis resulted in coefficients of determination that ranged from 0.22 to 0.73, and discriminant analysis further improved the overall predictive ability of rust models. Finally, contour plots of soil properties and rust levels clearly suggested a link between these two parameters. These combined data suggest that sugarcane growers that apply fertilizer in excess of plant requirements will increase the incidence and severity of rust infestations in their fields.

  1. Crop Yield and Soil Properties in the First 3 Years After Biochar Application to a Calcareous Soil

    Institute of Scientific and Technical Information of China (English)

    LIANG Feng; LI Gui-tong; LIN Qi-mei; ZHAO Xiao-rong

    2014-01-01

    It remains unclear whether biochar applications to calcareous soils can improve soil fertility and crop yield. A long-term ifeld experiment was established in 2009 so as to determine the effect of biochar on crop yield and soil properties in a calcareous soil. Five treatments were: 1) straw incorporation; 2) straw incorporation with inorganic fertilizer; 3), 4) and 5) straw incorporation with inorganic fertilizer, and biochar at 30, 60, and 90 t ha-1, respectively. The annual yield of either winter wheat or summer maize was not increased signiifcantly following biochar application, whereas the cumulative yield over the ifrst 4 growing seasons was signiifcantly increased. Soil pH, measured in situ, was increased by a maximum of 0.35 units after 2 yr following biochar application. After 3 yr, soil bulk density signiifcantly decreased while soil water holding capacity increased with adding biochar of 90 t ha-1. Alkaline hydrolysable N decreased but exchangeable K increased due to biochar addition. Olsen-P did not change compared to the treatment without biochar. The results suggested that biochar could be used in calcareous soils without yield loss or signiifcant impacts on nutrient availability.

  2. Soil Properties Database of Spanish Soils Volume IV.- Valencia and Murcia

    International Nuclear Information System (INIS)

    Trueba, C.; Millan, R.; Schmid, T.; Roquero, C; Magister, M.

    1998-01-01

    The soil vulnerability determines the sensitivity of the soil after an accidental radioactive contamination due to Cs-137 and Sr-90. The Departamento de Impacto Ambiental de la Energia of CIEMAT is carrying out an assessment of the radiological vulnerability of the different Spanish soils found on the Iberian Peninsula. This requires the knowledge of the soil properties for the various types of existing soils. In order to achieve this aim, a bibliographical compilation of soil profiles has been made to characterize the different soil types and create a database of their properties. Depending on the year of publication and the type of documentary source, the information compiled from the available bibliography is very heterogeneous. Therefore, an important effort has been made to normalize and process the information prior to its incorporation to the database. This volume presents the criteria applied to normalize and process the data as well as the soil properties of the various soil types belonging to the Comunidades Autonomas de Valencia and Murcia. (Author) 63 refs

  3. Soil Properties Database of Spanish Soils. Volume VI.- Andalucia (a): Jaen, Cordoba, Sevilla and Huelva

    International Nuclear Information System (INIS)

    Trueba, C; Milian, R.; Schmid, T.; Lago, C.; Roquero, C; Magister, M.

    1999-01-01

    The soil vulnerability determines the sensitivity of the soil after an accidental radioactive contamination due to Cs-137 and Sr-90. The Departamento de Impacto Ambiental de la Energia of CIEMAT is carrying out an assessment of the radiological vulnerability of the different Spanish soils found on the Iberian Peninsula. This requires the knowledge of the soil properties for the various types of existing soils. In order to achieve this aim, a bibliographical compilation of soil profiles has been made to characterize the different soil types and create a database of their properties. Depending on the year of publication and the type of documentary source, the information compiled from the available bibliography is very heterogeneous. Therefore, an important effort has been made to normalize and process the information prior to its incorporation to the database. This volume presents the criteria applied to normalize and process the data as well as the soil properties of the various soil types belonging to the provinces of Jaen, Cordoba, Sevilla and Huelva of the Comunidad Autonoma de Andalucia. (Author) 67 refs

  4. Soil Properties Database of Spanish Soils; Base de Datos de Propiedades Edafologicas de los Suelos Espanoles

    Energy Technology Data Exchange (ETDEWEB)

    Trueba, C.; Millan, R.; Schmid, T. [CIEMAT. Madrid (Spain); Roquero, C.; Magister, M. [UPM. Madrid (Spain)

    1998-12-31

    The soil vulnerability determines the sensitivity of the soil after an accidental radioactive contamination due to Cs-137 and Sr-90. The Departamento de Impacto Ambiental de la Energia of CIEMAT is carrying out an assessment of the radiological vulnerability of the different Spanish soils found on the Iberian Peninsula. This requires the knowledge of the soil properties for the various types of existing soils. In order to achieve this aim, a bibliographical compilation of soil profiles has been made to characterize the different soil types and create a database of their properties. Depending on the year of publication and the type of documentary source, the information compiled from the available bibliography is very heterogeneous. Therefore, an important effort has been made to normalize and process the information prior to its incorporation to the database. This volume presents the criteria applied to normalize and process the data as the soil properties of the various soil types belonging to the Comunidad Autonoma de Madrid. (Author) 39 refs.

  5. Soil Properties Database of Spanish Soils. Volume VII.- Andalucia (b): Cadiz, Malaga, Granada y Almeria

    International Nuclear Information System (INIS)

    Trueba, C.; Millan, R.; Schmid, T.; Lago, C.; Roquero, C; Magister, M.

    1999-01-01

    The soil vulnerability determines the sensitivity of the soil after an accidental radioactive contamination due to Cs-137 and Sr-90. The Departamento de Impacto Ambiental de la Energia of CIEMAT is carrying out an assessment of the radiological vulnerability of the different Spanish soils found on the Iberian Peninsula. This requires the knowledge of the soil properties for the various types of existing soils. In order to achieve this aim, a bibliographical compilation of soil profiles has been made to characterize the different soil types and create a database of their properties. Depending on the year of publication and the type of documentary source, the information compiled from the available bibliography is very heterogeneous. Therefore, an important effort has been made to normalize and process the information prior to its incorporation to the database. This volume presents the criteria applied to normalize and process the data as well as the soil properties of the various soil types belonging to the provinces of Cadiz, Malaga, Granada and Almeria of the Comunidad Autonoma de Andalucia. (Author) 78 refs

  6. Soil Properties Database of Spanish Soils. Volume XI.- Castilla-Leon (b): Palencia, Valladolid and Avila

    International Nuclear Information System (INIS)

    Trueba, C; Millan, R.; Schmid, T.; Lago, C.; Roquero, C; Magister, M.

    1999-01-01

    The soil vulnerability determines the sensitivity of the soil after an accidental radioactive contamination due to Cs-137 and Sr-90. The Departamento de Impacto Ambiental de la Energia of CIEMAT is carrying out an assessment of the radiological vulnerability of the different Spanish soils found on the Iberian Peninsula. This requires the knowledge of the soil properties for the various types of existing soils. In order to achieve this aim, a bibliographical compilation of soil profiles has been made to characterize the different soil types and create a database of their properties. Depending on the year of publication and the type of documentary source, the information compiled from the available bibliography is very heterogeneous. Therefore, an important effort has been made to normalize and process the information prior to its incorporation to the database. This volume presents the criteria applied to normalize and process the data as well as the soil properties of the various soil types belonging to the provinces of Palencia. Valladolid and Avila of the Comunidad Autonoma de Castilla-Leon. (Author) 41 refs

  7. Soil Properties Database of Spanish Soils. Volumen XIII.- Navarra and La Rioja

    International Nuclear Information System (INIS)

    Trueba, C; Millan, R.; Schmid, T.; Lago, C.; Roquero, C; Magister, M.

    1999-01-01

    The soil vulnerability determines the sensitivity of the soil after an accidental radioactive contamination due to Cs-137 and Sr-90. The Departamento de Impacto Ambiental de la Energia of CIEMAT is carrying out an assessment of the radiological vulnerability of the different Spanish soils found on the Iberian Peninsula. This requires the knowledge of the soil properties for the various types of existing soils. In order to achieve this aim, a bibliographical compilation of soil profiles has been made to characterize the different soil types and create a database of their properties. Depending on the year of publication and the type of documentary source, the information compiled from the available bibliography is very heterogeneous. Therefore, an important effort has been made to normalize and process the information prior to its incorporation to the database. This volume presents the criteria applied to normalize and process the data as well as the soil properties of the various soil types belonging to the Comunidades Autonomas of Navarra and La Rioja. (Author) 46 refs

  8. Soil Properties Database of Spanish Soils. Volume XII.- Castilla-Leon (c): Burgos, Soria and Segovia

    International Nuclear Information System (INIS)

    Trueba, C; Millan, R.; Schmid, T.; Lago, C.; Roquero, C; Magister, M.

    1999-01-01

    The soil vulnerability determines the sensitivity of the soil after an accidental radioactive contamination due to Cs-137 and Sr-90. The Departamento de Impacto Ambiental de la Energia of CIEMAT is carrying out an assessment of the radiological vulnerability of the different Spanish soils found on the Iberian Peninsula. This requires the knowledge of the soil properties for the various types of existing soils. In order to achieve this aim, a bibliographical compilation of soil profiles has been made to characterize the different soil types and create a database of their properties. Depending on the year of publication and the type of documentary source, the information compiled from the available bibliography is very heterogeneous. Therefore, an important effort has been made to normalize and process the information prior to its incorporation to the database. This volume presents the criteria applied to normalize and process the data as well as the soil properties of the various soil types belonging to the provinces of Burgos, Soria and Segovia of the Comunidad Autonoma de Castilla-Leon. (Author) 36 refs

  9. Soil Properties Database of Spanish Soils Volume II.- Asturias, Cantabria and Pais Vasco

    International Nuclear Information System (INIS)

    Trueba, C; Millan, R.; Schmid, T.; Roquero, C.; Magister, M.

    1998-01-01

    The soil vulnerability determines the sensitivity of the soil after an accidental radioactive contamination due to Cs-137 and Sr-90. The Departamento de Impacto Ambiental de la Energia of CIEMAT is carrying out an assessment of the radiological vulnerability of the different Spanish soils found on the Iberian Peninsula. This requires the knowledge of the soil properties for the various types of existing soils. In order to achieve this aim, a bibliographical compilation of soil profiles has been made to characterize the different soil types and create a database of their properties. Depending on the year of publication and the type of documentary source, the information compiled from the available bibliography is very heterogeneous. Therefore. an important effort has been made to normalize and process the information prior to its incorporation to the database. This volume presents the criteria applied to normalize and process the data as well as the soil properties of the various soil types belonging to the Comunidades Autonomas de Asturias, Cantabria and Pais Vasco. (Author) 34 refs

  10. Soil Properties Database of Spanish Soils. Volume X.- Castilla-Leon (a): Leon, Zamora and Salamanca

    International Nuclear Information System (INIS)

    Trueba, C; Millan, R.; Schmid, T.; Lago, C.; Roquero, C; Magister, M.

    1999-01-01

    The soil vulnerability determines the sensitivity of the soil after an accidental radioactive contamination due to Cs-137 and Sr-90. The Departamento de Impacto Ambiental de la Energia of CIEMAT is carrying out an assessment of the radiological vulnerability of the different Spanish soils found on the Iberian Peninsula. This requires the knowledge of the soil properties for the various types of existing soils. In order to achieve this aim, a bibliographical compilation of soil profiles has been made to characterize the different soil types and create a database of their properties. Depending on the year of publication and the type of documentary source, the information compiled from the available bibliography is very heterogeneous. Therefore, an important effort has been made to normalize and process the information prior to its incorporation to the database. This volume presents the criteria applied to normalize and process the data as well as the soil properties of the various soil types belonging to the provinces of Leon, Zamora and Salamanca of the Comunidad Autonoma de Castilla-Leon. (Author) 41 refs

  11. Soil carbon and soil physical properties response to incorporating mulched forest slash

    Science.gov (United States)

    Felipe G. Sanchez; Emily A. Carter; John. F. Klepac

    2000-01-01

    A study was installed in the Lower Coastal Plain near Washington, NC, to test the hypothesis that incorporating organic matter in the form of comminuted forest slash would increase soil carbon and nutrient pools, and alter soil physical properties to favor pine growth. Two sites were selected, an organic and a mineral site, to compare the treatment effects on...

  12. Analysis of the spatial variability of crop yield and soil properties in small agricultural plots

    Directory of Open Access Journals (Sweden)

    Vieira Sidney Rosa

    2003-01-01

    Full Text Available The objective of this study was to assess spatial variability of soil properties and crop yield under no tillage as a function of time, in two soil/climate conditions in São Paulo State, Brazil. The two sites measured approximately one hectare each and were cultivated with crop sequences which included corn, soybean, cotton, oats, black oats, wheat, rye, rice and green manure. Soil fertility, soil physical properties and crop yield were measured in a 10-m grid. The soils were a Dusky Red Latossol (Oxisol and a Red Yellow Latossol (Ultisol. Soil sampling was performed in each field every two years after harvesting of the summer crop. Crop yield was measured at the end of each crop cycle, in 2 x 2.5 m sub plots. Data were analysed using semivariogram analysis and kriging interpolation for contour map generation. Yield maps were constructed in order to visually compare the variability of yields, the variability of the yield components and related soil properties. The results show that the factors affecting the variability of crop yield varies from one crop to another. The changes in yield from one year to another suggest that the causes of variability may change with time. The changes with time for the cross semivariogram between phosphorus in leaves and soybean yield is another evidence of this result.

  13. Environmental and management impacts on temporal variability of soil hydraulic properties

    Science.gov (United States)

    Bodner, G.; Scholl, P.; Loiskandl, W.; Kaul, H.-P.

    2012-04-01

    Soil hydraulic properties underlie temporal changes caused by different natural and management factors. Rainfall intensity, wet-dry cycles, freeze-thaw cycles, tillage and plant effects are potential drivers of the temporal variability. For agricultural purposes it is important to determine the possibility of targeted influence via management. In no-till systems e.g. root induced soil loosening (biopores) is essential to counteract natural soil densification by settling. The present work studies two years of temporal evolution of soil hydraulic properties in a no-till crop rotation (durum wheat-field pea) with two cover crops (mustard and rye) having different root systems (taproot vs. fibrous roots) as well as a bare soil control. Soil hydraulic properties such as near-saturated hydraulic conductivity, flow weighted pore radius, pore number and macroporosity are derived from measurements using a tension infiltrometer. The temporal dynamics are then analysed in terms of potential driving forces. Our results revealed significant temporal changes of hydraulic conductivity. When approaching saturation, spatial variability tended to dominate over the temporal evolution. Changes in near-saturated hydraulic conductivity were mainly a result of changing pore number, while the flow weighted mean pore radius showed less temporal dynamic in the no-till system. Macroporosity in the measured range of 0 to -10 cm pressure head ranged from 1.99e-4 to 8.96e-6 m3m-3. The different plant coverage revealed only minor influences on the observed system dynamics. Mustard increased slightly the flow weighted mean pore radius, being 0.090 mm in mustard compared to 0.085 mm in bare soil and 0.084 mm in rye. Still pore radius changes were of minor importance for the overall temporal dynamics. Rainfall was detected as major driving force of the temporal evolution of structural soil hydraulic properties at the site. Soil hydraulic conductivity in the slightly unsaturated range (-7 cm to -10

  14. Modelling soil properties in a crop field located in Croatia

    Science.gov (United States)

    Bogunovic, Igor; Pereira, Paulo; Millan, Mesic; Percin, Aleksandra; Zgorelec, Zeljka

    2016-04-01

    Development of tillage activities had negative effects on soil quality as destruction of soil horizons, compacting and aggregates destruction, increasing soil erosion and loss of organic matter. For a better management in order to mitigate the effects of intensive soil management in land degradation it is fundamental to map the spatial distribution of soil properties (Brevik et al., 2016). The understanding the distribution of the variables in space is very important for a sustainable management, in order to identify areas that need a potential intervention and decrease the economic losses (Galiati et al., 2016). The objective of this work is study the spatial distribution of some topsoil properties as clay, fine silt, coarse silt, fine sand, coarse sand, penetration resistance, moisture and organic matter in a crop field located in Croatia. A grid with 275x25 (625 m2) was designed and a total of 48 samples were collected. Previous to data modelling, data normality was checked using the Shapiro wilk-test. As in previous cases (Pereira et al., 2015), data did not followed the normal distribution, even after a logarithmic (Log), square-root, and box cox transformation. Thus, for modeling proposes, we used the log transformed data, since was the closest to the normality. In order to identify groups among the variables we applied a principal component analysis (PCA), based on the correlation matrix. On average clay content was 15.47% (±3.23), fine silt 24.24% (±4.08), coarse silt 35.34% (±3.12), fine sand 20.93% (±4.68), coarse sand 4.02% (±1.69), penetration resistance 0.66 MPa (±0.28), organic matter 1.51% (±0.25) and soil moisture 32.04% (±3.27). The results showed that the PCA identified three factors explained at least one of the variables. The first factor had high positive loadings in soil clay, fine silt and organic matter and a high negative loading in fine sand. The second factor had high positive loadings in coarse sand and moisture and a high

  15. Use of photoacoustic mid-infrared spectroscopy to characterize soil properties and soil organic matter stability

    Science.gov (United States)

    Peltre, Clement; Bruun, Sander; Du, Changwen; Stoumann Jensen, Lars

    2014-05-01

    The persistence of soil organic matter (SOM) is recognized as a major ecosystem property due to its key role in earth carbon cycling, soil quality and ecosystem services. SOM stability is typically studied using biological methods such as measuring CO2-C evolution from microbial decomposition of SOM during laboratory incubation or by physical or chemical fractionation methods, allowing the separation of a labile fraction of SOM. However these methods are time consuming and there is still a need for developing reliable techniques to characterize SOM stability, providing both quantitative measurements and qualitative information, in order to improve our understanding of the mechanisms controlling SOM persistence. Several spectroscopic techniques have been used to characterize and predict SOM stability, such as near infrared reflectance spectroscopy (NIRS) and diffuse reflectance mid-infrared spectroscopy (DRIFT). The latter allows a proper identification of spectral regions corresponding to vibrations of specific molecular or functional groups associated with SOM lability. However, reflectance spectroscopy for soil analyses raises some difficulties related to the low reflectance of soils, and to the high influence of particle size. In the last three decades, the progresses in microphone sensitivity dramatically increased the performance of photoacoustic Fourier transform mid-infrared spectroscopy (FTIR-PAS). This technique offers benefits over reflectance spectroscopy techniques, because particle size and the level of sample reflectance have little effect of on the PAS signal, since FTIR-PAS is a direct absorption technique. Despite its high potential for soil analysis, only a limited number of studies have so far applied FTIR-PAS for soil characterization and its potential for determining SOM degradability still needs to be investigated. The objective of this study was to assess the potential of FTIR-PAS for the characterization of SOM decomposability during

  16. Combined impacts of land use and soil property changes on soil erosion in a mollisol area under long-term agricultural development.

    Science.gov (United States)

    Ouyang, Wei; Wu, Yuyang; Hao, Zengchao; Zhang, Qi; Bu, Qingwei; Gao, Xiang

    2018-02-01

    Soil erosion exhibits special characteristics in the process of agricultural development. Understanding the combined impacts of land use and soil property changes on soil erosion, especially in the area under long-term agricultural cultivations, is vital to watershed agricultural and soil management. This study investigated the temporal-spatial patterns of the soil erosion based on a modified version of Universal Soil Loss Equation (USLE) and conducted a soil erosion contribution analysis. The land use data were interpreted from Landsat series images, and soil properties were obtained from field sampling, laboratory tests and SPAW (Soil-Plant-Atmosphere-Water) model calculations. Over a long period of agricultural development, the average erosion modulus decreased from 187.7tkm -2 a -1 in 1979 to 158.4tkm -2 a -1 in 2014. The land use types were transformed mainly in the reclamation of paddy fields and the shrinking of wetlands on a large scale. Most of the soils were converted to loam from silty or clay loam and the saturated hydraulic conductivity (K s ) of most soil types decreased by 1.11% to 43.6%. The rapidly increasing area of 49.8km 2 of paddy fields together with the moderate decrease of 14.0km 2 of forests, as well as K s values explained 87.4% of the total variance in soil erosion. Although changes in soil physical and water characteristics indicated that soil erosion loads should have become higher, the upsurge in paddy fields played an important role in mitigating soil erosion in this study area. These results demonstrated that land use changes had more significant impacts than soil property changes on soil erosion. This study suggested that rational measures should be taken to extend paddy fields and control the dry land farming. These findings will benefit watershed agricultural targeting and management. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Soil property maps of Africa at 250 m resolution

    Science.gov (United States)

    Kempen, Bas; Hengl, Tomislav; Heuvelink, Gerard B. M.; Leenaars, Johan G. B.; Walsh, Markus G.; MacMillan, Robert A.; Mendes de Jesus, Jorge S.; Shepherd, Keith; Sila, Andrew; Desta, Lulseged T.; Tondoh, Jérôme E.

    2015-04-01

    Vast areas of arable land in sub-Saharan Africa suffer from low soil fertility and physical soil constraints, and significant amounts of nutrients are lost yearly due to unsustainable soil management practices. At the same time it is expected that agriculture in Africa must intensify to meet the growing demand for food and fiber the next decades. Protection and sustainable management of Africa's soil resources is crucial to achieve this. In this context, comprehensive, accurate and up-to-date soil information is an essential input to any agricultural or environmental management or policy and decision-making model. In Africa, detailed soil information has been fragmented and limited to specific zones of interest for decades. To help bridge the soil information gap in Africa, the Africa Soil Information Service (AfSIS) project was established in 2008. AfSIS builds on recent advances in digital soil mapping, infrared spectroscopy, remote sensing, (geo)statistics, and integrated soil fertility management to improve the way soils are evaluated, mapped, and monitored. Over the period 2008-2014, the AfSIS project has compiled two soil profile data sets (about 28,000 unique locations): the Africa Soil Profiles (legacy) database and the AfSIS Sentinel Site (new soil samples) database -- the two data sets represent the most comprehensive soil sample database of the African continent to date. In addition a large set of high-resolution environmental data layers (covariates) was assembled. The point data were used in the AfSIS project to generate a set of maps of key soil properties for the African continent at 250 m spatial resolution: sand, silt and clay fractions, bulk density, organic carbon, total nitrogen, pH, cation-exchange capacity, exchangeable bases (Ca, K, Mg, Na), exchangeable acidity, and Al content. These properties were mapped for six depth intervals up to 2 m: 0-5 cm, 5-15 cm, 15-30 cm, 30-60 cm, 60-100 cm, and 100-200 cm. Random forests modelling was used to

  18. Influence of Robinia pseudoacacia short rotation coppice on soil physical properties

    Science.gov (United States)

    Xavier, Morvan; Isabelle, Bertrand; Gwenaelle, Gibaud

    2015-04-01

    Human activities can lead to the degradation of soil physical properties. For instance, machinery traffic across the land can induce the development of compacted areas at the wheel tracks. It leads to a decrease in porosity which results in a decrease of the hydraulic conductivity, and therefore, prevents water infiltration and promotes surface runoff. Land use, soil management and soil cover also have a significant influence on soil physical properties (Kodesova et al., 2011). In the arable land, surface runoff and soil erosion are enhanced by the absence of soil cover for part of the year and by the decrease of aggregate stability due to a decline of soil organic matter. In that context, few studies focused on the effects of a Robinia pseudoacacia short rotation coppice (SRC) on soil physical properties. Therefore, this study aims to determine the effect of the conversion of a grassland in a SRC on soil physical properties. These properties have also been compared to those of arable land and natural forest. For that, in several plots of the experimental farm of Grignon (30 km west of Paris, France), different measurements were performed: i) soil water retention on a pressure plate apparatus for 7 water potential between 0 and 1500 kPa, ii) bulk density using the method for gravelly and rocky soil recommended by the USDA, iii) aggregate stability using the method described in Le Bissonnais (1996), and iv) soil hydraulic conductivity using a Guelph permeameter. All these measurements were performed on the same soil type and on different land uses: arable land (AL), grassland (GL), natural forest (NF) and short rotation coppice (SRC) of Robinia pseudoacacia planted 5 years ago. Soil water retention measurements are still under progress and will be presented in congress. Bulk density measurements of the AL, GL and SRC are not significantly different. They ranged from 1.32 to 1.42. Only the NF measurements are significantly lower than the other (0.97). Aggregate

  19. A review of the impacts of degradation threats on soil properties in the UK.

    Science.gov (United States)

    Gregory, A S; Ritz, K; McGrath, S P; Quinton, J N; Goulding, K W T; Jones, R J A; Harris, J A; Bol, R; Wallace, P; Pilgrim, E S; Whitmore, A P

    2015-10-01

    National governments are becoming increasingly aware of the importance of their soil resources and are shaping strategies accordingly. Implicit in any such strategy is that degradation threats and their potential effect on important soil properties and functions are defined and understood. In this paper, we aimed to review the principal degradation threats on important soil properties in the UK, seeking quantitative data where possible. Soil erosion results in the removal of important topsoil and, with it, nutrients, C and porosity. A decline in soil organic matter principally affects soil biological and microbiological properties, but also impacts on soil physical properties because of the link with soil structure. Soil contamination affects soil chemical properties, affecting nutrient availability and degrading microbial properties, whilst soil compaction degrades the soil pore network. Soil sealing removes the link between the soil and most of the 'spheres', significantly affecting hydrological and microbial functions, and soils on re-developed brownfield sites are typically degraded in most soil properties. Having synthesized the literature on the impact on soil properties, we discuss potential subsequent impacts on the important soil functions, including food and fibre production, storage of water and C, support for biodiversity, and protection of cultural and archaeological heritage. Looking forward, we suggest a twin approach of field-based monitoring supported by controlled laboratory experimentation to improve our mechanistic understanding of soils. This would enable us to better predict future impacts of degradation processes, including climate change, on soil properties and functions so that we may manage soil resources sustainably.

  20. Measurement and characteristics of microbial biomass in forest soils

    International Nuclear Information System (INIS)

    Vance, E.D.

    1986-01-01

    The soil microbial biomass is the primary agent responsible for the breakdown and mineralization of soil organic matter and plays a major role in regulating nutrient availability to plants. In this study, methods for measuring biomass in soil were compared and tested in forest soils ranging in pH from 3.2 to 7.2. A good relationship between biomass C measured using the chloroform fumigation-incubation method and soil ATP or microbial biomass C by direct microscopy was found in soils at or above pH 4.2. The fumigation-incubation method consistently underestimated biomass C in soils below pH 4.2, however. Hypotheses for the breakdown of the fumigation-incubation method in strongly acid soils were tested by using an alterative fumigant, measuring the proportion of added 14 C labelled fungi and bacteria decomposed in fumigated soils (k/sub C/), and by studying the effect of large, non-fumigated soil inocula on the flush of respiration following fumigation. These studies indicated that the failure of the method in strongly acid soils was due to inhibited decomposition of non-microbial soil organic matter by the microbial recolonizing population following fumigation. A modified method for measuring biomass C by fumigation-incubation in acid soils is proposed

  1. Development of biochemical properties in anthropic soil (the study at Třinec–Jahodná plot

    Directory of Open Access Journals (Sweden)

    Karel Marosz

    2013-01-01

    Full Text Available The properties of the anthropic soils formed at the sludge bed “Třinec-Jahodná”. The sludge bed came from a long-time depositing of fly-ash and slag layers. Therefore, the anthropic soil properties obtained their features by both a character of layered substrate and a management of the local land reclamation. The paper presented deals with the rate of an intensity of biological and biochemical soil processes in charge of the fulfilment of plant nourishment demands, and the time viewpoints focusing on the local soil development. The set of enzymatic and biological measurements were chosen for treatments of soil bodies sampled throughout 2007–2008. The study plots inside the sludge bed and the control plot were sampled; the properties of particular horizons were studied. The results proved that the twenty-year-development of soil bodies made the proper conditions for plant nutrition. The positive statement, nevertheless, is directly linked to the presence of trees and shrubs. The vegetation seems to be one of the very crucial factors for a status of the site and maintenance of soil productivity: it affects temperature amplitudes, sensitivity to erosion, a redistribution of soil water, and a humic compounds accumulation. The statistical analyses showed significantly differing results on the study plots with a shorter development and a lower rate of vegetational cover.

  2. Prescribed burning impact on forest soil properties--a Fuzzy Boolean Nets approach.

    Science.gov (United States)

    Castro, Ana C Meira; Paulo Carvalho, Joao; Ribeiro, S

    2011-02-01

    The Portuguese northern forests are often and severely affected by wildfires during the Summer season. These occurrences significantly affect and negatively impact all ecosystems, namely soil, fauna and flora. In order to reduce the occurrences of natural wildfires, some measures to control the availability of fuel mass are regularly implemented. Those preventive actions concern mainly prescribed burnings and vegetation pruning. This work reports on the impact of a prescribed burning on several forest soil properties, namely pH, soil moisture, organic matter content and iron content, by monitoring the soil self-recovery capabilities during a one year span. The experiments were carried out in soil cover over a natural site of Andaluzitic schist, in Gramelas, Caminha, Portugal, which was kept intact from prescribed burnings during a period of four years. Soil samples were collected from five plots at three different layers (0-3, 3-6 and 6-18) 1 day before prescribed fire and at regular intervals after the prescribed fire. This paper presents an approach where Fuzzy Boolean Nets (FBN) and Fuzzy reasoning are used to extract qualitative knowledge regarding the effect of prescribed fire burning on soil properties. FBN were chosen due to the scarcity on available quantitative data. The results showed that soil properties were affected by prescribed burning practice and were unable to recover their initial values after one year. Copyright © 2010 Elsevier Inc. All rights reserved.

  3. Low temperature thermophysical properties of lunar soil

    Science.gov (United States)

    Cremers, C. J.

    1973-01-01

    The thermal conductivity and thermal diffusivity of lunar fines samples from the Apollo 11 and Apollo 12 missions, determined at low temperatures as a function of temperature and various densities, are reviewed. It is shown that the thermal conductivity of lunar soil is nearly the same as that of terrestrial basaltic rock under the same temperature and pressure conditions.

  4. The Characteristics of Electrical and Physical Properties of Peat Soil in Rasau Village, West Kalimantan

    Science.gov (United States)

    Aminudin, A.; Hasanah, T. R.; Iryati, M.

    2018-05-01

    The Electrical and physical properties can be used as indicators for measuring soil conditions. One of the methods developed in agricultural systems to obtain information on soil conditions is through measuring of electrical conductivity. Peat soil is one of the natural resources that exist in Indonesia. This study aims to determine the characteristics of peat soil in Rasau village, West Kalimantan. This research was conducted by the properties of electrical conductivity and water content using 5TE Water Contents and EC Sensor equipment, but also to know the change of physical nature of peat soil covering peat soil and peat type. The results showed that the electrical conductivity value of 1-4 samples was 0.02 -0.29 dS/m and the volume water content value (VWC) was 0.255-0.548 m3/m3 and the physical characteristics obtained were peat colour brown to dark brown that allegedly the soil still has a very high content of organic material derived from weathering plants and there are discovery of wood chips, wood powder and leaf powder on the ground. Knowing the information is expected to identify the land needs to be developed to be considered for future peat soil utilization.

  5. Improvement of engineering soil properties using non -traditional additives

    Directory of Open Access Journals (Sweden)

    Waheed Mohanned

    2018-01-01

    Full Text Available Laboratory experiments are conducted to evaluate the effect of some non-traditional additives on the engineering properties of clayey soil, which show problematic phenomenon when used as a construction material. The conducted tests covered the influence of these additives on various parameters like consistency limits, compaction characteristics and CBR value. Two nontraditional stabilizers are selected in this study, polymers and phosphoric acid at three different percent which are (1%, 3% and 5% of the dry soil weight. It is concluded that addition of the polymer to the clayey soil results in a slight increase in plastic limit while the liquid limit is not affected accompanied by a marginal decrease in the dry unit weight while the optimum moisture content remains unaffected. The addition of phosphoric acid to the clayey soil has no effect on its Atterberg limits. In general, it is observed that polymer is found to be ineffective as a stabilizer to improve clayey soils, especially in small amounts of about (3%. The phosphoric acid treated soil gained better improvement for all amounts of additive used. For (3% acid treated soil the CBR is about (360% compared to that of untreated soil, for that, it can be concluded that the improvement using phosphoric acid in the clay soils is a promising option and can be applied to solve the geotechnical stabilization problems.

  6. Electrodialytic Remediation of Pb Contaminated Soil - Effects of Soil Properties and Pb Distribution

    DEFF Research Database (Denmark)

    Pedersen, Anne Juul; Jensen, Pernille Erland

    1999-01-01

    The aim of this work was to investigate the effects of soil properties and Pb distribution on the electrodialytic remediation of Pb contaminated soil. Two naturally Pb contaminated soils were compared with respect to total Pb content, Pb distribution, pH, carbonate content, clay content and organic...... matter, and an electrodialytic remediation experiment was made on each soil.It was concluded that soil pH was the most important factor limiting the mobilisation of Pb. In one of the remediation experiments it was possible to mobilise and reduce the amount of Pb significantly, whereas in the other only...... a small amount of the initial Pb was mobilised at similar experimental conditions. A high buffering capacity of one of the soils, which was partly due to a high carbonate content, led to a bad remediation result....

  7. Soil heat flux measurements in an open forest

    NARCIS (Netherlands)

    vanderMeulen, MJW; Klaassen, W; Kiely, G

    1996-01-01

    The soil surface heat flux in an open oak forest was determined at four locations to account for the heterogeneity of the forest. Soil temperatures and soil water content were measured at several depths and an integration method with three layers was used. The thickness of the bottom layer was

  8. Soil Heat Flux Measurements in an Open Forest

    NARCIS (Netherlands)

    Meulen, M.W.J. van der; Klaassen, W.

    1996-01-01

    The soil surface heat flux in an open oak forest was determined at four locations to account for the heterogeneity of the forest. Soil temperatures and soil water content were measured at several depths and an integration method with three layers was used. The thickness of the bottom layer was

  9. Compost amendment of sandy soil affects soil properties and greenhouse tomato productivity

    DEFF Research Database (Denmark)

    Arthur, Emmanuel; Cornelis, W.; Razzaghi, Fatemeh

    2012-01-01

    Sandy soils, with low productivity, could be improved by compost application to sustain crop production. This study aimed to examine the effect of three compost types (vegetable, fruit and yard waste compost, garden waste compost, and spent mushroom compost) on basic properties of a loamy sand...... compost had greater effect in improving tomato productivity. A decade-long application of composts on loamy sand improved basic chemical and physical properties which were reflected in increased fruit yield in tomato. Since no negative effect of compost was observed, we suggest that sandy soils may serve...... and greenhouse tomato productivity. Disturbed and intact soil samples were taken from a decade-long compost field experiment on loamy sand with three compost types at application rate of 30 m3 ha-1 yr-1 (7.5 ton ha-1 yr-1). The soils were characterized for chemical and physical properties. Tomato was planted...

  10. Study on the influence factors about the soil radon measurement

    International Nuclear Information System (INIS)

    Wu Zixiang; Liu Yanbin; Jia Yuxin; Mai Weiji; Liu Xiaolian; Yang Yuhua

    2006-01-01

    Objective: To explore relevant factors about the soil radon measurement and provide gist of formulating correct measure method by studying the way of the soil radon measurement. Methods: Deflation-ionization room standard is adopted. Results: The concentration of soil radon becomes higher with the sample's volume added, it also augmented with the measure depth increased in certain degree; The concentration of soil radon changes little when sample's depth is above 60 cm; The time of deflation has no obvious influence on the concentration of soil radon, but microwave show serious effect on it; The results will be lowered when the desiccant is humidified, raining has the same affection on it; Plant has some impact on it. Conclusion: The measured results will be affected by microwave, oscillate and plant. Sample's volume and depth, soil's humidity can influence it too. The result's veracity can be guaranteed by choosing appropriate sample and measure condition. (authors)

  11. Analysis of soil hydraulic and thermal properties for land surface modeling over the Tibetan Plateau

    Science.gov (United States)

    Zhao, Hong; Zeng, Yijian; Lv, Shaoning; Su, Zhongbo

    2018-06-01

    Soil information (e.g., soil texture and porosity) from existing soil datasets over the Tibetan Plateau (TP) is claimed to be inadequate and even inaccurate for determining soil hydraulic properties (SHP) and soil thermal properties (STP), hampering the understanding of the land surface process over TP. As the soil varies across three dominant climate zones (i.e., arid, semi-arid and subhumid) over the TP, the associated SHP and STP are expected to vary correspondingly. To obtain an explicit insight into the soil hydrothermal properties over the TP, in situ and laboratory measurements of over 30 soil property profiles were obtained across the climate zones. Results show that porosity and SHP and STP differ across the climate zones and strongly depend on soil texture. In particular, it is proposed that gravel impact on porosity and SHP and STP are both considered in the arid zone and in deep layers of the semi-arid zone. Parameterization schemes for porosity, SHP and STP are investigated and compared with measurements taken. To determine the SHP, including soil water retention curves (SWRCs) and hydraulic conductivities, the pedotransfer functions (PTFs) developed by Cosby et al. (1984) (for the Clapp-Hornberger model) and the continuous PTFs given by Wösten et al. (1999) (for the Van Genuchten-Mualem model) are recommended. The STP parameterization scheme proposed by Farouki (1981) based on the model of De Vries (1963) performed better across the TP than other schemes. Using the parameterization schemes mentioned above, the uncertainties of five existing regional and global soil datasets and their derived SHP and STP over the TP are quantified through comparison with in situ and laboratory measurements. The measured soil physical properties dataset is available at https://data.4tu.nl/repository/uuid:c712717c-6ac0-47ff-9d58-97f88082ddc0" target="_blank">https://data.4tu.nl/repository/uuid:c712717c-6ac0-47ff-9d58-97f88082ddc0.

  12. Gamma-ray remote sensing of soil properties in a forested area near Batlow, NSW

    International Nuclear Information System (INIS)

    Bierwirth, P.N.; Aspin, S.J.; Ryan, P.J.; McKenzie, N.J.

    1998-01-01

    In forested and agricultural areas, reflective remote sensing methods are of limited utility for soil studies due to the variable effects of vegetation. Airborne gamma-ray remote sensing is presented here as a useful technique for soils. Short wavelength gamma-rays are detected from the upper 0.30-0.45 m of the soil . They are emitted from radioactive elements in the soil and largely pass through vegetation cover. In this paper, images of gamma parent elements (K, Th and U) are presented and element associations with soil properties and vegetation are analysed for a forested area near Batlow, NSW. Effects of vegetation are evident in gamma-ray data and in Landsat TM along powerlines and in clearings. A technique for removing this effect in the gamma-ray data is demonstrated. Detailed soil and rock chemistry together with ground gamma-spectrometer measurements were collected to support the interpretation and analysis of the image data. The work focuses mainly on the variation of soil properties within areas mapped as granodiorite lithology. Many areas of deep red soils are accurately mapped by the radiometric K data. The precise origin of these soils is not clear and their parent materials may include contributions from aeolian deposition, in situ weathering of granodiorite, and remnant basalt. . In areas of granodiorite, K patterns are interpreted to be a function of the degree of mineral weathering and can be related to soil depth and erosion status. This study demonstrates the effectiveness of gamma-ray remote sensing for directly mapping soil units and properties (authors). Copyright (1998) Remote Sensing and Photogrammetry Association of Australasia Ltd

  13. Drought monitoring with soil moisture active passive (SMAP) measurements

    Science.gov (United States)

    Mishra, Ashok; Vu, Tue; Veettil, Anoop Valiya; Entekhabi, Dara

    2017-09-01

    Recent launch of space-borne systems to estimate surface soil moisture may expand the capability to map soil moisture deficit and drought with global coverage. In this study, we use Soil Moisture Active Passive (SMAP) soil moisture geophysical retrieval products from passive L-band radiometer to evaluate its applicability to forming agricultural drought indices. Agricultural drought is quantified using the Soil Water Deficit Index (SWDI) based on SMAP and soil properties (field capacity and available water content) information. The soil properties are computed using pedo-transfer function with soil characteristics derived from Harmonized World Soil Database. The SMAP soil moisture product needs to be rescaled to be compatible with the soil parameters derived from the in situ stations. In most locations, the rescaled SMAP information captured the dynamics of in situ soil moisture well and shows the expected lag between accumulations of precipitation and delayed increased in surface soil moisture. However, the SMAP soil moisture itself does not reveal the drought information. Therefore, the SMAP based SWDI (SMAP_SWDI) was computed to improve agriculture drought monitoring by using the latest soil moisture retrieval satellite technology. The formulation of SWDI does not depend on longer data and it will overcome the limited (short) length of SMAP data for agricultural drought studies. The SMAP_SWDI is further compared with in situ Atmospheric Water Deficit (AWD) Index. The comparison shows close agreement between SMAP_SWDI and AWD in drought monitoring over Contiguous United States (CONUS), especially in terms of drought characteristics. The SMAP_SWDI was used to construct drought maps for CONUS and compared with well-known drought indices, such as, AWD, Palmer Z-Index, sc-PDSI and SPEI. Overall the SMAP_SWDI is an effective agricultural drought indicator and it provides continuity and introduces new spatial mapping capability for drought monitoring. As an

  14. Strength properties of sandy soil-cement admixtures

    OpenAIRE

    Sara Rios; António Joaquim Pereira Viana Da Fonseca

    2009-01-01

    This paper will focus on the sensitivity of strength and stiffness properties of silty-sands, from granitic residual soil, which can be converted to a highly improved material if stabilized with cement. The study of soil stabilization with cement demands to quantify the influence of the cement percentage, porosity and water content adopted in the admixing process for different stresses and physical states. Firstly, this influence was quantified in terms of the unconfined strength and maximum ...

  15. Influence of Tillage and Mulch on Soil Physical Properties and ...

    African Journals Online (AJOL)

    User

    tillage along with plastic mulch have positive impact on soil physical properties, root growth, water use efficiency ... positive effects on crop yield (Gla & Kulig,. 2008). ... potash fertilizers were applied at 120, 100 and 60 .... 0-10. 1.57B. 1.57B. 1.57B. 1.8B. 1.7B. 1.8B. Tillage × Soil depth. CTInitial. 0-5 ...... (Brassica napus). Eur.

  16. Effects of Soil Compaction on Carbon and Nitrogen Sequestration in Soil and Wheat, Soil Physical Properties and Aggregates Stability (Case study: Northern of Aq Qala

    Directory of Open Access Journals (Sweden)

    Z. Saieedifar

    2016-09-01

    Full Text Available Introduction: Soil compaction has become a widespread problem in the world and it is considered as one of the main factors affecting land degradation in arid and semi-arid agricultural land. Compaction in arable soils is a gradual phenomenon that appearing over time and most important factors that influence it include: soil properties, high clay content, low organic matter, and frequency of wet-dry in the soil, impervious layer of soil, load heavy agricultural implements and soil and water mismanagement. Compaction induced soil degradation affects about 68 million hectares of land globally. The vast majority of compaction in modern agriculture is caused by vehicular traffic. Carbon sequestration by long-term management operation of the plant and soil, not only increase the soil carbon storage but also lead to reduce the carbon exchange and greenhouse gases emissions like CO2 from the soil profile. The aim of this study was evaluating the effect of soil compaction on carbon and nitrogen sequestration of wheat and soil and some soil physical properties such as: aggregate stability, saturated soil moisture content, bulk density and soil porosity. Materials and Methods: This experiment was accomplished in which is located near Aq Qala in a randomized completely block design (with 4 treatments and 3 replications. Soil compaction was artificially created by using a 5/7 ton heavy tractor. The treatments arrangements were: 1 T1: control, 2 T2: twice passing of tractor, 3 T3: four time of passing tractor, and 4 T4: six time of passing heavy tractor. Utilize of all agricultural inputs (fertilizers, herbicides, etc. has been identical for all treatments. Since rain-fed farming is the common method to cultivation of cereals in the study area, so no complementary irrigation was carried out in this period. In this study, after the measurement of the parameters, the data were analyzed by using SPSS 16.0 Software. LSD test was used for comparison of means

  17. Mineralogic and compositional properties of Martian soil and dust: results from Mars Pathfinder

    Science.gov (United States)

    Bell, J.F.; McSween, H.Y.; Crisp, J.A.; Morris, R.V.; Murchie, S.L.; Bridges, N.T.; Johnson, J. R.; Britt, D.T.; Golombek, M.P.; Moore, H.J.; Ghosh, A.; Bishop, J.L.; Anderson, R.C.; Brückner, J.; Economou, T.; Greenwood, J.P.; Gunnlaugsson, H.P.; Hargraves, R.M.; Hviid, S.; Knudsen, J.M.; Madsen, M.B.; Reid, R.; Rieder, R.; Soderblom, L.

    2000-01-01

    Mars Pathfinder obtained multispectral, elemental, magnetic, and physical measurements of soil and dust at the Sagan Memorial Station during the course of its 83 sol mission. We describe initial results from these measurements, concentrating on multispectral and elemental data, and use these data, along with previous Viking, SNC meteorite, and telescopic results, to help constrain the origin and evolution of Martian soil and dust. We find that soils and dust can be divided into at least eight distinct spectral units, based on parameterization of Imager for Mars Pathfinder (IMP) 400 to 1000 nm multispectral images. The most distinctive spectral parameters for soils and dust are the reflectivity in the red, the red/blue reflectivity ratio, the near-IR spectral slope, and the strength of the 800 to 1000 nm absorption feature. Most of the Pathfinder spectra are consistent with the presence of poorly crystalline or nanophase ferric oxide(s), sometimes mixed with small but varying degrees of well-crystalline ferric and ferrous phases. Darker soil units appear to be coarser-grained, compacted, and/or mixed with a larger amount of dark ferrous materials relative to bright soils. Nanophase goethite, akaganeite, schwertmannite, and maghemite are leading candidates for the origin of the absorption centered near 900 nm in IMP spectra. The ferrous component in the soil cannot be well-constrained based on IMP data. Alpha proton X-ray spectrometer (APXS) measurements of six soil units show little variability within the landing site and show remarkable overall similarity to the average Viking-derived soil elemental composition. Differences exist between Viking and Pathfinder soils, however, including significantly higher S and Cl abundances and lower Si abundances in Viking soils and the lack of a correlation between Ti and Fe in Pathfinder soils. No significant linear correlations were observed between IMP spectral properties and APXS elemental chemistry. Attempts at constraining

  18. Dynamic soil properties in response to anthropogenic disturbance

    Science.gov (United States)

    Vanacker, Veerle; Ortega, Raúl

    2013-04-01

    Anthropogenic disturbance of natural vegetation can profoundly alter the physical, chemical and biological processes within soils. Rapid removal of topsoil during intense farming can result in an imbalance between soil production through chemical weathering and physical erosion, with direct implications on local biogeochemical cycling. However, the feedbacks between soil erosion, chemical weathering and biogeochemical cycling in response to anthropogenic forcing are not yet fully understood. Here, we study dynamic soil properties for a rapidly changing anthropogenic landscape, and focus on the coupling between physical erosion, soil production and soil chemical weathering. The archaeological site of Santa Maria de Melque (Toledo, Central Spain) was selected for its remarkably long occupation history dating back to the 7th century AD. As part of the agricultural complex, four retention reservoirs were built in the Early Middle Ages. The sedimentary archive was used to track the evolution in sedimentation rates and geochemical properties of the sediment. Catchment-wide soil erosion rates vary slightly between the various occupation phases (7th century-now), but are of the same magnitude as the cosmogenic nuclide-derived erosion rates. However, there exists large spatial variation in physical erosion rates that are coupled with chemical weathering intensities. The sedimentary records suggest that there are important changes in the spatial pattern of sediment source areas through time as a result of changing land use patterns

  19. Effects of Salt Accumulation in Soil by Evaporation on Unsaturated Soil Hydraulic Properties

    Science.gov (United States)

    Liu, Y.; Liu, Q.

    2017-12-01

    Soil salinization is one type of soil degradation caused by saline groundwater evaporation. Salt accumulation in the soil will change the pore structure of soil, which should change the unsaturated soil hydraulic properties including the soil water characteristic curve (SWCC). To investigate the effect of salt accumulation on the SWCC and find the best suitable SWCC model to characterize the relationship of soil moisture and soil matrix potential, we have conducted laboratory SWCC experiments with the soil columns saturated by NaCl solution with different concentration (deionized water, 3 g/L, 15 g/L, 50 g/L, 100 g/L and 200 g/L). As the concentration of initial solution increases, the matrix potential corresponding to the same moisture increases. As the water was evaporated, the salt would precipitate in soil continuously, which would decrease the porosity of soils and increase the negative pressure of soils. With higher initial concentration, the more salt accumulation caused the more residual water content in the soils. For van Genuchten-Mualem model, the residual water contents θr were 0.0159, 0.0181, 0.0182, 0.0328, 0.0312, 0.0723, 0.0864 in the columns initially saturated by deionized water, 3 g/L, 15 g/L, 50 g/L, 100 g/L and 200 g/L, respectively. The van Genuchten-Mualem model, Fredlund-Xing model, Gardern model, Mckee-Bumb model and Brooks-Corey model were fitted by MATLAB with the experiments data, and the fitted coefficients were compared. The Fredlund-Xing model has the best fitting coefficients and the calculated value was consistent with the observed data.

  20. The impact of ants on mineral soil properties and processes at different spatial scales

    NARCIS (Netherlands)

    Cammeraat, E.L.H.; Risch, A.C.

    2008-01-01

    Soil dwelling ants are important soil engineers that have a large impact on the soil ecosystem. This is reflected in the alteration of soil properties by ants due to burrowing activities, the accumulation of organic matter and other nutrients in the soil, which, in turn, alters soil physical,

  1. Cacao Crop Management Zones Determination Based on Soil Properties and Crop Yield

    Directory of Open Access Journals (Sweden)

    Perla Silva Matos de Carvalho

    Full Text Available ABSTRACT: The use of management zones has ensured yield success for numerous agricultural crops. In spite of this potential, studies applying precision agricultural techniques to cacao plantations are scarce or almost nonexistent. The aim of the present study was to delineate management zones for cacao crop, create maps combining soil physical properties and cacao tree yield, and identify what combinations best fit within the soil chemical properties. The study was conducted in 2014 on a cacao plantation in a Nitossolo Háplico Eutrófico (Rhodic Paleudult in Bahia, Brazil. Soil samples were collected in a regular sampling grid with 120 sampling points in the 0.00-0.20 m soil layer, and pH(H2O, P, K+, Ca2+, Mg2+, Na+, H+Al, Fe, Zn, Cu, Mn, SB, V, TOC, effective CEC, CEC at pH 7.0, coarse sand, fine sand, clay, and silt were determined. Yield was measured in all the 120 points every month and stratified into annual, harvest, and early-harvest cacao yields. Data were subjected to geostatistical analysis, followed by ordinary kriging interpolation. The management zones were defined through a Fuzzy K-Means algorithm for combinations between soil physical properties and cacao tree yield. Concordance analysis was carried out between the delineated zones and soil chemical properties using Kappa coefficients. The zones that best classified the soil chemical properties were defined from the early-harvest cacao yield map associated with the clay or sand fractions. Silt content proved to be an inadequate variable for defining management zones for cacao production. The delineated management zones described the spatial variability of the soil chemical properties, and are therefore important for site-specific management in the cacao crop.

  2. Gap assessment in current soil monitoring networks across Europe for measuring soil functions

    Science.gov (United States)

    van Leeuwen, J. P.; Saby, N. P. A.; Jones, A.; Louwagie, G.; Micheli, E.; Rutgers, M.; Schulte, R. P. O.; Spiegel, H.; Toth, G.; Creamer, R. E.

    2017-12-01

    Soil is the most important natural resource for life on Earth after water. Given its fundamental role in sustaining the human population, both the availability and quality of soil must be managed sustainably and protected. To ensure sustainable management we need to understand the intrinsic functional capacity of different soils across Europe and how it changes over time. Soil monitoring is needed to support evidence-based policies to incentivise sustainable soil management. To this aim, we assessed which soil attributes can be used as potential indicators of five soil functions; (1) primary production, (2) water purification and regulation, (3) carbon sequestration and climate regulation, (4) soil biodiversity and habitat provisioning and (5) recycling of nutrients. We compared this list of attributes to existing national (regional) and EU-wide soil monitoring networks. The overall picture highlighted a clearly unbalanced dataset, in which predominantly chemical soil parameters were included, and soil biological and physical attributes were severely under represented. Methods applied across countries for indicators also varied. At a European scale, the LUCAS-soil survey was evaluated and again confirmed a lack of important soil biological parameters, such as C mineralisation rate, microbial biomass and earthworm community, and soil physical measures such as bulk density. In summary, no current national or European monitoring system exists which has the capacity to quantify the five soil functions and therefore evaluate multi-functional capacity of a soil and in many countries no data exists at all. This paper calls for the addition of soil biological and some physical parameters within the LUCAS-soil survey at European scale and for further development of national soil monitoring schemes.

  3. Improving geotechnical properties of clayey soil using polymer material

    Directory of Open Access Journals (Sweden)

    Karim Hussein

    2018-01-01

    Full Text Available This study illustrates the application of polymer material for clayey soil stabilization. The article will focus on studying the strength behavior of the clayey soils reinforced with homogenously polymer fiber. In the current research, “polypropylene” was selected as polymer material to reinforce the natural clay soil. This polymer fiber was added to the clayey soil with four different percentages of (0, 1.5, 3, and 5% by weight of soil. Various tests with different polymer contents were performed to study the effect of using such a polymer as a stabilizing agent on geotechnical properties of clay. As the fiber content increases, the optimum moisture content (OMC is increased while the specific gravity decreases. For Atterberg’s limits, the results indicated increasing liquid limit and plasticity index while decreasing plastic limit with increase in polymer content. The outcomes of the tests also reflected a considerable improvement in the unconfined compressive strength with noticeable improvement in the shear strength parameter (undrained shear strength, cu of the treated soils. The undrained shear strength obtained from treated soil with 5% polymer addition is more than three times that of the untreated soil. With an increase in polymer content, the consolidation parameters (Compression index Cc and recompression index Cr decreases. Finally, the benefit of the reinforcement is increased with increasing polymer fiber content.

  4. EFFECT OF SOIL PROPERTIES ON LEAD BIOAVAILABILITY AND TOXCITY TO EARTHWORMS

    Science.gov (United States)

    Soil properties are important factors modifying metal bioavailability to ecological receptors. Twenty-one soils with a wide range of soil properties were amended with a single concentration of Pb (2000 mg/kg) to determine the effects of soil properties on Pb bioavailability and ...

  5. Physical Properties of Sandy Soil Affected by Soil Conditioner Under Wetting and Drying cycles

    Directory of Open Access Journals (Sweden)

    M.I. Choudhary

    1998-06-01

    Full Text Available Information on the effectiveness of soil conditioners over a prolonged period is scarce. A laboratory experiment was undertaken to evaluate the effectiveness of a polyacrylamide (Broadleaf P4 soil conditioner on the physical properties of sandy soil subjected to wetting and drying cycles. Four concentrations of Broadleaf P4 0, 0.2, 0.4, and 0.6% on dry weight basis were uniformly mixed with a calcareous sandy soil. Addition of Broadleaf P4 to sandy soil increased the water holding capacity, decreased the bulk density, and increased the porosity and void ratio at 0 and 16 wetting and drying cycles. The coefficient of linear extensibility increased considerably with increasing concentrations of the polymer. The addition of polymer at 0 and 16 cycles increased considerably the retention and availability of water in sandy soil. Saturated hydraulic conductivity decreased with increasing concentrations of Broadleaf P4 whereas unsaturated hydraulic conductivity at 0 and 16 cycles showed an increase with increasing soil moisture contents. After I6 wetting and drying cycles, the capacity of the soil to hold water was lost on average by 15.8% when compared to the 0 wetting and drying cycle. The effectiveness of the soil conditioner on bulk density, coefficient of linear extensibility, available water and saturated hydraulic conductivity was reduced on average by 14.1, 24.5, 21.l and 53.7% respectively. The significant changes in soil properties between 0 and 16 cycles suggested that the effectiveness of the conditioner decreased with the application of wetting and drying cycles. However, its effect was still considerable when compared to untreated soil under laboratory conditions.

  6. CHANGE OF CHOSEN SOIL PHYSICAL PROPERTIES OF CHERNOZEM AFTER SEVEN YEARS OF NO-TILL SOIL CULTIVATION

    Directory of Open Access Journals (Sweden)

    Katarna Hrckov

    2014-09-01

    Full Text Available Soil physical properties were investigated in two types of growing systems - integrated no-till system and conventional system with ploughing, in 1999 2005 on chernozem in maize growing region. Bulk density decreased and total porosity increased during 7 years in both growing systems. In integrated system the improvement of soil physical properties could be explained by remaining of plant residues on soil surface. In conventional system the plant residues were incorporated into soil by ploughing. This led to the higher proportion of organic matter in soil. Soil cultivated conventionally had significantly higher value of reduced bulk density, significantly lower porosity and significantly higher values of soil moisture compared to soil in integrated no-till system. Maximum capillary water capacity was not significantly influenced by soil cultivation. Values of investigated soil physical properties in both systems were not markedly different from the typical values of cultivated chernozem.

  7. Interfacial characterization of soil-embedded optical fiber for ground deformation measurement

    International Nuclear Information System (INIS)

    Zhang, Cheng-Cheng; Zhu, Hong-Hu; Shi, Bin; She, Jun-Kuan

    2014-01-01

    Recently fiber-optic sensing technologies have been applied for performance monitoring of geotechnical structures such as slopes, foundations, and retaining walls. However, the validity of measured data from soil-embedded optical fibers is strongly influenced by the properties of the interface between the sensing fiber and the soil mass. This paper presents a study of the interfacial properties of an optical fiber embedded in soil with an emphasis on the effect of overburden pressure. Laboratory pullout tests were conducted to investigate the load-deformation characteristics of a 0.9 mm tight-buffered optical fiber embedded in soil. Based on a tri-linear interfacial shear stress-displacement relationship, an analytical model was derived to describe the progressive pullout behavior of an optical fiber from soil matrix. A comparison between the experimental and predicted results verified the effectiveness of the proposed pullout model. The test results are further interpreted and discussed. It is found that the interfacial bond between an optical fiber and soil is prominently enhanced under high overburden pressures. The apparent coefficients of friction of the optical fiber/soil interface decrease as the overburden pressure increases, due to the restrained soil dilation around the optical fiber. Furthermore, to facilitate the analysis of strain measurement, three working states of a soil-embedded sensing fiber were defined in terms of two characteristic displacements. (paper)

  8. Photometric Properties of Soils at the Mars Phoenix Landing Site: Preliminary Analysis from CRISM EPF Data

    Science.gov (United States)

    Cull, S. C.; Arvidson, R. E.; Seelos, F.; Wolff, M. J.

    2010-03-01

    Using data from CRISM's Emission Phase Function observations, we attempt to constrain Phoenix soil scattering properties, including soil grain size, single-scattering albedo, and surface phase function.

  9. Relating soil solution Zn concentration to diffusive gradients in thin films measurements in contaminated soils.

    Science.gov (United States)

    Degryse, Fien; Smolders, Erik; Oliver, Ian; Zhang, Hao

    2003-09-01

    The technique of diffusive gradients in thin films (DGT) has been suggested to sample an available fraction of metals in soil. The objectives of this study were to compare DGT measurements with commonly measured fractions of Zn in soil, viz, the soil solution concentration and the total Zn concentration. The DGT technique was used to measure fluxes and interfacial concentrations of Zn in three series of field-contaminated soils collected in transects toward galvanized electricity pylons and in 15 soils amended with ZnCl2 at six rates. The ratio of DGT-measured concentration to pore water concentration of Zn, R, varied between 0.02 and 1.52 (mean 0.29). This ratio decreased with decreasing distribution coefficient, Kd, of Zn in the soil, which is in agreement with the predictions of the DGT-induced fluxes in soils (DIFS) model. The R values predicted with the DIFS model were generally larger than the observed values in the ZnCl2-amended soils at the higher Zn rates. A modification of the DIFS model indicated that saturation of the resin gel was approached in these soils, despite the short deployment times used (2 h). The saturation of the resin with Zn did not occur in the control soils (no Zn salt added) or the field-contaminated soils. Pore water concentration of Zn in these soils was predicted from the DGT-measured concentration and the total Zn content. Predicted values and observations were generally in good agreement. The pore water concentration was more than 5 times underpredicted for the most acid soil (pH = 3) and for six other soils, for which the underprediction was attributed to the presence of colloidal Zn in the soil solution.

  10. Management of soil physical properties of lowland puddled rice soil for sustainable food production

    International Nuclear Information System (INIS)

    Bhagat, R.M.

    2004-01-01

    About 3 billion people who rely on rice as their staple food today will have multiplied to some 4.4 billion by the middle of this century. With rice demand growing at an average rate of about 3 percent annually, 70 percent more rice has to be produced in next 30 years compared to present day production levels. More rice has to come from less favorable environments, with less water and nutrients. Agricultural population densities on Asia's rice producing lands are among the highest in the world and continue to increase at a remarkable rate. Rice has widely adapted itself: to the hot Australian and Egyptian deserts, to the cool Himalayan foothills of Nepal. Hill tribes in Southeast Asia plant it on slash-and-burned forest slopes; that's upland rice. However, low lying areas in Asia, which are subject to uncontrolled flooding, are home to more than 100 million poor farmers. Puddling or wet tillage in rice, decreases total soil porosity only slightly, but markedly changes porosity distribution with both storage and residual porosity increasing at the expanse of transmission porosity. Soil texture plays an important role in soil water retention following soil disturbance. Cracking pattern of the soils is studied after six years of different levels of regular addition of residue. Cracking pattern at a soil surface affects the hydrodynamic properties of soil. Cracking extends the soil-air interface into the soil profile and thereby may increase the moisture loss through evaporation

  11. Accuracy of soil stress measurements as affected by transducer dimensions and shape

    DEFF Research Database (Denmark)

    Lamandé, Mathieu; Keller, Thomas; Berisso, Feto Esimo

    2015-01-01

    Accurate measurements of soil stress are needed to evaluate the impact of traffic on soil properties and prevent soil compaction. Four types of transducer commonly used to measure vertical stress were calibrated in realistic traffic conditions in the field. The four transducer types differed...... in shape and dimensions, which are important factors influencing stress. Deviation of measured stress from true stress ranged from 15% underestimation to 18% overestimation, with transducer thickness to width ratio being the most important shape factor influencing the stress recorded. Changes in physical...... conditions in the soil above the transducers due to their installation did not influence the accuracy of vertical stress measurements. The results of this calibration are valid for correcting stress measurements in topsoil, but should be used with caution for vertical stress measurements in subsoil. All...

  12. Soil Tillage Conservation and its Effect on Soil Properties Bioremediation and Sustained Production of Crops

    Science.gov (United States)

    Rusu, Teodor; Ioana Moraru, Paula; Muresan, Liliana; Andriuca, Valentina; Cojocaru, Olesea

    2017-04-01

    soil features resulted in a positive impact on the water permeability of the soil. Availability of soil moisture during the crop growth resulted in better plant water status. Subsequent release of conserved soil water regulated proper plant water status, soil structure, and lowered soil penetrometer resistance. Productions obtained at STC did not have significant differences for the wheat and maize crop but were higher for soybean. The advantages of minimum soil tillage systems for Romanian pedo-climatic conditions can be used to improve methods in low producing soils with reduced structural stability on sloped fields, as well as measures of water and soil conservation on the whole agroecosystem. Presently, it is necessary to make a change concerning the concept of conservation practices and to consider a new approach regarding the good agricultural practice. We need to focus on an upper level concerning conservation by focusing on soil quality. Carbon management is necessary for a complexity of matters including soil, water management, field productivity, biological fuel and climatic change. In conclusion a Sustainable Agriculture includes a range of complementary agricultural practices: (i) minimum soil tillage (through a system of reduced tillage or no-tillage) to preserve the structure, fauna and soil organic matter; (ii) permanent soil cover (cover crops, residues and mulches) to protect the soil and help to remove and control weeds; (iii) various combinations and rotations of the crops which stimulate the micro-organisms in the soil and controls pests, weeds and plant diseases. Acknowledgements: This paper was performed under the frame of the Partnership in priority domains - PNII, developed with the support of MEN-UEFISCDI, project no. PN-II-PT-PCCA-2013-4-0015: Expert System for Risk Monitoring in Agriculture and Adaptation of Conservative Agricultural Technologies to Climate Change, and International Cooperation Program - Sub-3.1. Bilateral AGROCEO c. no. 21BM

  13. The effects of vegetation and soil hydraulic properties on passive microwave sensing of soil moisture: Data report for the 1982 fiels experiments

    Science.gov (United States)

    Oneill, P.; Jackson, T.; Blanchard, B. J.; Vandenhoek, R.; Gould, W.; Wang, J.; Glazar, W.; Mcmurtrey, J., III

    1983-01-01

    Field experiments to (1) study the biomass and geometrical structure properties of vegetation canopies to determine their impact on microwave emission data, and (2) to verify whether time series microwave data can be related to soil hydrologic properties for use in soil type classification. Truck mounted radiometers at 1.4 GHz and 5 GHz were used to obtain microwave brightness temperatures of bare vegetated test plots under different conditions of soil wetness, plant water content and canopy structure. Observations of soil moisture, soil temperature, vegetation biomass and other soil and canopy parameters were made concurrently with the microwave measurements. The experimental design and data collection procedures for both experiments are documented and the reduced data are presented in tabular form.

  14. Adsorption of mercury compounds by tropical soils. I. Adsorption in soil profiles in relation to their physical, chemical, and mineralogical properties

    Energy Technology Data Exchange (ETDEWEB)

    Semu, E.; Singh, B.R.; Selmer-Olsen, A.R.

    1986-01-01

    Mercury adsorption of HgCl/sub 2/ and 2-methoxyethylmercury chloride (Aretan) (100 mg Hg L/sup -1/) was measured for three soil profiles from Morogoro, Arusha, and Dar es Salaam in Tanzania. The adsorption was investigated for the physical, chemical, and mineralogical properties of soils. All soil samples showed greater capacity for adsorption of Aretan than for HgCl/sub 2/. In the Morogoro profile Hg adsorption decreased with depth but in the other two soils, the minimum adsorption occurred in the third horizon and increased both upwards and downwards. In the Morogoro profile, Aretan adsorption correlated well with pH. Adsorption of both Aretan and HgCl/sub 2/ correlated well with the distribution of organic C and with the cation exchange capacity of the soils. In the Arusha and Dar es Salaam profiles Hg adsorption was not significantly correlated with any of the soil properties tested.

  15. Avoidance test with Enchytraeus albidus (Enchytraeidae): Effects of different exposure time and soil properties

    International Nuclear Information System (INIS)

    Amorim, Monica J.B.; Novais, Sara; Roembke, Joerg; Soares, Amadeu M.V.M.

    2008-01-01

    Enchytraeids are ecologically relevant soil species and are commonly used in standardized toxicity tests. Their rapid reaction to a chemical exposure can be used as a toxicological measurement endpoint that assesses the avoidance behavior. The objectives of this investigation were to determine the effects of soil properties on the avoidance behavior of Enchytraeus albidus and to optimize the duration of avoidance test. The avoidance tests included (1) exposures in OECD artificial soil with standard or modified properties (pH, clay or peat content), and (2) exposures to copper chloride, cadmium chloride, and to the organic pesticides dimethoate and phenmedipham for different time periods. Results showed that alteration of OECD soil constituents significantly affected the avoidance behavior of enchytraeids, and that the 48-h exposure was the optimal duration of the test. Consideration of soil properties is important for selecting appropriate experimental design and interpreting the results of the enchytraeid avoidance test. - Optimal duration of the avoidance tests with potworm Enchytraeus albidus is 48 h; soil properties can affect performance of the test species

  16. Analysis of problems and failures in the measurement of soil-gas radon concentration.

    Science.gov (United States)

    Neznal, Martin; Neznal, Matěj

    2014-07-01

    Long-term experience in the field of soil-gas radon concentration measurements allows to describe and explain the most frequent causes of failures, which can appear in practice when various types of measurement methods and soil-gas sampling techniques are used. The concept of minimal sampling depth, which depends on the volume of the soil-gas sample and on the soil properties, is shown in detail. Consideration of minimal sampling depth at the time of measurement planning allows to avoid the most common mistakes. The ways how to identify influencing parameters, how to avoid a dilution of soil-gas samples by the atmospheric air, as well as how to recognise inappropriate sampling methods are discussed. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  17. Controls on the spatial variability of key soil properties: comparing field data with a mechanistic soilscape evolution model

    Science.gov (United States)

    Vanwalleghem, T.; Román, A.; Giraldez, J. V.

    2016-12-01

    There is a need for better understanding the processes influencing soil formation and the resulting distribution of soil properties. Soil properties can exhibit strong spatial variation, even at the small catchment scale. Especially soil carbon pools in semi-arid, mountainous areas are highly uncertain because bulk density and stoniness are very heterogeneous and rarely measured explicitly. In this study, we explore the spatial variability in key soil properties (soil carbon stocks, stoniness, bulk density and soil depth) as a function of processes shaping the critical zone (weathering, erosion, soil water fluxes and vegetation patterns). We also compare the potential of a geostatistical versus a mechanistic soil formation model (MILESD) for predicting these key soil properties. Soil core samples were collected from 67 locations at 6 depths. Total soil organic carbon stocks were 4.38 kg m-2. Solar radiation proved to be the key variable controlling soil carbon distribution. Stone content was mostly controlled by slope, indicating the importance of erosion. Spatial distribution of bulk density was found to be highly random. Finally, total carbon stocks were predicted using a random forest model whose main covariates were solar radiation and NDVI. The model predicts carbon stocks that are double as high on north versus south-facing slopes. However, validation showed that these covariates only explained 25% of the variation in the dataset. Apparently, present-day landscape and vegetation properties are not sufficient to fully explain variability in the soil carbon stocks in this complex terrain under natural vegetation. This is attributed to a high spatial variability in bulk density and stoniness, key variables controlling carbon stocks. Similar results were obtained with the mechanistic soil formation model MILESD, suggesting that more complex models might be needed to further explore this high spatial variability.

  18. Soil volumetric water content measurements using TDR technique

    Directory of Open Access Journals (Sweden)

    S. Vincenzi

    1996-06-01

    Full Text Available A physical model to measure some hydrological and thermal parameters in soils will to be set up. The vertical profiles of: volumetric water content, matric potential and temperature will be monitored in different soils. The volumetric soil water content is measured by means of the Time Domain Reflectometry (TDR technique. The result of a test to determine experimentally the reproducibility of the volumetric water content measurements is reported together with the methodology and the results of the analysis of the TDR wave forms. The analysis is based on the calculation of the travel time of the TDR signal in the wave guide embedded in the soil.

  19. Effect of nanoclay particles on some physical and mechanical properties of soils

    Directory of Open Access Journals (Sweden)

    H Sharifnasab

    2016-04-01

    compression and shear parameters of soil were investigated. Materials and Methods: The study was done for 2 years at the Research Institute of Agricultural Engineering Soil Dynamics Laboratory in a completely randomized design with three replications. Soil samples were used for different soil textures. Three types of soil texture, light, medium and heavy were considered. Nanoclay has a mineral base and can improve the properties of the soil. Two levels of the nanoclay containing zero and one percent of the nanoclay, 3 to 6 treatments in different physical and mechanical tests were repeated. The test specimens were prepared in triplicate test and physical, mechanical and chemical testing was performed according to ASTM standard on all models. Mesh test samples were performed by sieve and hydrometer methods according to standard ASTM-D422-98. Plastic soil properties were expressed by the Atterberg Limits, measure the ability to absorb water, soil and to a fine particle adhesion amount and type of fine particles in the soil. Psychological testing was performed to determine the extent and the paste according to ASTM-D4318-98 standard. The maximum dry density and optimum moisture content of the soil compaction characteristics are the most important soil properties such as soil density development projects are in operation. In agricultural applications, in particular for tillage, these two factors are of particular importance. In this study, Praktor standard density testing was performed on the different treatments. In this research, not consolidate Undrained (UU testing methods were used. The stress tests were done at three levels 100, 200 and 300 kPa respectively. Results and Discussion: Adding nanoparticles of clay significant impact on the size of the samples did not curve. As well as to determine the impact of nano-clay soil Plastic characteristics as psychological tests and the paste was treated on the results of these tests for different treatments and repeated ANOVA

  20. Enhancing the engineering properties of expansive soil using bagasse ash

    Science.gov (United States)

    Silmi Surjandari, Niken; Djarwanti, Noegroho; Umri Ukoi, Nafisah

    2017-11-01

    This paper deals with stabilization of expansive soil on a laboratory experimental basis. The aim of the research was to evaluate the enhancement of the engineering properties of expansive soil using bagasse ash. The soil is treated with bagasse ash by weight (0, 5, 10, 15, and 20%) based on dry mass. The performance of bagasse ash stabilized soil was evaluated using physical and strength performance tests, namely the plasticity index, standard Proctor compaction, and percentage swelling. An X-ray diffraction (XRD) test was conducted to evaluate the clay mineral, whereas an X-ray fluorescence (XRF) was to the chemical composition of bagasse ash. From the results, it was observed that the basic tests carried out proved some soil properties after the addition of bagasse ash. Furthermore, the plasticity index decreased from 53.18 to 47.70%. The maximum dry density of the specimen increased from 1.13 to 1.24 gr/cm3. The percentage swelling decreased from 5.48 to 3.29%. The outcomes of these tests demonstrate that stabilization of expansive soils using bagasse ash can improve the strength.

  1. Magnetic Properties of Different-Aged Chernozemic Soils

    Science.gov (United States)

    Fattakhova, Leysan; Shinkarev, Alexandr; Kosareva, Lina; Nourgaliev, Danis; Shinkarev, Aleksey; Kondrashina, Yuliya

    2016-04-01

    We investigated the magnetic properties and degree of mineral weathering in profiles of different-aged chernozemic soils derived from a uniform parent material. In this work, layer samples of virgin leached chernozem and chernozemic soils formed on the mound of archaeological earthy monument were used. The characterization of the magnetic properties was carried out on the data of the magnetometry and differential thermomagnetic analysis. The evaluation of the weathering degree was carried out on a loss on ignition, cation exchange capacity and X-ray phase analysis on the data of the original soil samples and samples of the heavy fraction of minerals. It was found that the magnetic susceptibility enhancement in humus profiles of newly formed chernozemic soils lagged significantly behind the organic matter content enhancement. This phenomenon is associated with differences in kinetic parameters of humus formation and structural and compositional transformation of the parent material. It is not enough time of 800-900 years to form a relatively "mature" magnetic profile. These findings are well consistent with the chemical kinetic model (Boyle et al., 2010) linking the formation of the soils magnetic susceptibility with the weathering of primary Fe silicate minerals. Different-aged chernozemic soils are at the first stage of formation of a magnetic profile when it is occur an active production of secondary ferrimagnetic minerals from Fe2+ released by primary minerals.

  2. Soil physical properties of high mountain fields under bauxite mining

    Directory of Open Access Journals (Sweden)

    Dalmo Arantes de Barros

    2013-10-01

    Full Text Available Mining contributes to the life quality of contemporary society, but can generate significant impacts, these being mitigated due to environmental controls adopted. This study aimed to characterize soil physical properties in high-altitude areas affected by bauxite mining, and to edaphic factors responses to restoration techniques used to recover mined areas in Poços de Caldas plateau, MG, Brazil. The experiment used 3 randomized block design involving within 2 treatments (before mining intervention and after environmental recovery, and 4 replicates (N=24. In each treatment, soil samples with deformed structures were determined: granulometry, water-dispersible clay content, flocculation index, particle density, stoniness level, water aggregate stability, and organic matter contend. Soil samples with preserved structures were used to determine soil density and the total volume of pores, macropores, and micropores. Homogenization of stoniness between soil layers as a result of soil mobilization was observed after the mined area recovery. Stoniness decreased in 0.10-0.20 m layer after recovery, but was similar in the 0-0.10 m layer in before and after samples. The recovery techniques restored organic matter levels to pre-mining levels. However, changes in soil, including an increase in soil flocculation degree and a decrease in water-dispersible clays, were still apparent post-recovery. Furthermore, mining operations caused structural changes to the superficial layer of soil, as demonstrated by an increase in soil density and a decrease in total porosity and macroporosity. Decreases in the water stability of aggregates were observed after mining operations.

  3. Application of MCPA herbicide on soils amended with biostimulants: short-time effects on soil biological properties.

    Science.gov (United States)

    Tejada, Manuel; García-Martínez, Ana M; Gómez, Isidoro; Parrado, Juan

    2010-08-01

    In this paper we studied in the laboratory the effect of MCPA herbicide at a rate of 1.5lha(-1) (manufactures rate recommended) on biological properties of a Plagic Antrosol amended with four biostimulants (WCDS, wheat condensed distillers soluble; PA-HE, hydrolyzed poultry feathers; CGHE, carob germ enzymatic extract; and RB, rice bran extract). Seven hundred grams of soil were mixed with WCDS at a rate of 10%, CGHE at a rate of 4.7%, PA-HE at a rate of 4.3%, and RB at a rate of 4.4%, respectively, in order to applying the same amount of organic matter to the soil (16.38 g organic matter). An unamended polluted and amended non-polluted soil were used as control. For all treatments, the soil ergosterol, dehydrogenase, urease, and phosphatase activities were measured at two incubation times (0 and 60 d). The 16S rDNA-DGGE profiles in all treatments were determined at the beginning and end of the incubation period. The results indicated that at the end of the incubation period and compared with the control soil, the dehydrogenase, urease and phosphatase activities and ergosterol decreased 39.3%, 20%, 15.7% and 56.5%, respectively in the non-organic amended polluted soil. The application of organic matter to unpolluted soil increased the enzymatic activities and ergosterol. However, this stimulation was higher in the soil amended with RB, followed by PA-HE, WCDS and CGHE. The application of herbicide in organic-amended soils decreased the enzymatic activities and ergosterol content. However, this decrease was lower than for the non-amended herbicide polluted soil. Possibly the low molecular weight protein content easily assimilated by soil microorganisms and the adsorption capacity of humic substances are responsible for less inhibition of these enzyme activities and soil ergosterol. The 16S rDNA-DGGE profiles indicated that herbicide did not negatively affect soil bacterial biodiversity. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  4. General Relationships between Abiotic Soil Properties and Soil Biota across Spatial Scales and Different Land-Use Types

    Science.gov (United States)

    Birkhofer, Klaus; Schöning, Ingo; Alt, Fabian; Herold, Nadine; Klarner, Bernhard; Maraun, Mark; Marhan, Sven; Oelmann, Yvonne; Wubet, Tesfaye; Yurkov, Andrey; Begerow, Dominik; Berner, Doreen; Buscot, François; Daniel, Rolf; Diekötter, Tim; Ehnes, Roswitha B.; Erdmann, Georgia; Fischer, Christiane; Foesel, Bärbel; Groh, Janine; Gutknecht, Jessica; Kandeler, Ellen; Lang, Christa; Lohaus, Gertrud; Meyer, Annabel; Nacke, Heiko; Näther, Astrid; Overmann, Jörg; Polle, Andrea; Pollierer, Melanie M.; Scheu, Stefan; Schloter, Michael; Schulze, Ernst-Detlef; Schulze, Waltraud; Weinert, Jan; Weisser, Wolfgang W.; Wolters, Volkmar; Schrumpf, Marion

    2012-01-01

    Very few principles have been unraveled that explain the relationship between soil properties and soil biota across large spatial scales and different land-use types. Here, we seek these general relationships using data from 52 differently managed grassland and forest soils in three study regions spanning a latitudinal gradient in Germany. We hypothesize that, after extraction of variation that is explained by location and land-use type, soil properties still explain significant proportions of variation in the abundance and diversity of soil biota. If the relationships between predictors and soil organisms were analyzed individually for each predictor group, soil properties explained the highest amount of variation in soil biota abundance and diversity, followed by land-use type and sampling location. After extraction of variation that originated from location or land-use, abiotic soil properties explained significant amounts of variation in fungal, meso- and macrofauna, but not in yeast or bacterial biomass or diversity. Nitrate or nitrogen concentration and fungal biomass were positively related, but nitrate concentration was negatively related to the abundances of Collembola and mites and to the myriapod species richness across a range of forest and grassland soils. The species richness of earthworms was positively correlated with clay content of soils independent of sample location and land-use type. Our study indicates that after accounting for heterogeneity resulting from large scale differences among sampling locations and land-use types, soil properties still explain significant proportions of variation in fungal and soil fauna abundance or diversity. However, soil biota was also related to processes that act at larger spatial scales and bacteria or soil yeasts only showed weak relationships to soil properties. We therefore argue that more general relationships between soil properties and soil biota can only be derived from future studies that consider

  5. Effect of Metakaolin on the geotechnical properties of Expansive Soil

    Directory of Open Access Journals (Sweden)

    Mahmoud D. Ahmed

    2015-12-01

    Full Text Available Expansive soil spreads in Iraq and some countries of the world. But there are many problems can be occurred to the structures that built on, so we must study the characteristics of these soils due to the problems that may be caused to these structures which built on these kinds of soil and then study the methods of treatment. The present study focuses on improving the geotechnical properties of expansive soils by treating it Metakaolin(M. Metakaolin (M has never been used before as an improvement material for stabilizing the expansive soil . Metakaolin is a pozzolanic material. It’s obtained by calcination of kaolinite clay at temperatures from 700°C to 800°C. Kaolin chemical composition is basically aluminous silicates hydrates associated with Mn, Fe, Ca, K, Na. Its crystal has a lattice structure of tetrahedral and octahedral layers with interplanar distance of 7.2 Å. The soil used in the present study can be classified according to the Unified Soil Classification System as clay with high plasticity (CH .

  6. Measurement of 222Rn in soil concentrations in interstitial air

    International Nuclear Information System (INIS)

    Duenas, C.; Fernandez, M.C.; Carretero, J.; Liger, E.

    1996-01-01

    Measurements of 222 Rn soil concentrations were made by inserting stainless-steel sampling tubes into the soil. The samples of the soil interstitial air were taken in to pre-evacuated 1 L glass flasks. The glass flasks are cylindrical and coated with a film of ZnS(Ag). 222 Rn was measured by counting the alpha particles emitted by 222 Rn and its daughter products, 218 Po and 214 Bi, when they reached radioactive equilibrium. Measurements of 222 Rn gas concentrations in the soil air interstices by the method at different depths were used to calculate the diffusion coefficient of the 222 Rn in the soil air. This study has been carried out for diverse soils. (Author)

  7. Mercury content in volcanic soils across Europe and its relationship with soil properties

    Energy Technology Data Exchange (ETDEWEB)

    Pena-Rodriguez, Susana; Fernandez-Calvino, David; Arias-Estevez, Manuel; Novoa-Munoz, Juan Carlos [Vigo Univ., Ourense (Spain). Area de Edafoloxia e Quimica Agricola; Pontevedra-Pombal, Xabier; Taboada, Teresa; Martinez-Cortizas, Antonio; Garcia-Rodeja, Eduardo [Universidad de Santiago, Coruna (Spain). Dept. Edafoloxia e Quimica Agricola

    2012-04-15

    Volcanoes are a natural source of Hg, whose deposition can occur in neighbouring soils. This study examines the role of soil compounds in the geochemical behaviour of total Hg (Hg{sub T}) in volcanic soils. An estimation of Hg from lithological origin is also assessed to ascertain the relevance of other sources in Hg{sub T} accumulated in volcanic soils. Twenty soil profiles developed from volcanic materials and located across European volcanic regions were selected for this study. The general characterisation of soils included total C, N and S content and Al and Fe distribution determined using traditional methods. The total content of major and trace elements was determined using X-ray fluorescence spectrometry (XRF). The total Hg content of soil samples was measured with atomic absorption spectroscopy using a solid sample Hg analyser. Lithogenic Hg was calculated in the uppermost soil considering Al, Ti and Zr as conservative reference elements. Several statistical analyses (Pearson correlations, Mann-Whitney tests, stepwise multiple regressions and analysis of variance) were carried to ascertain the role of soil parameters and characteristics in the Hg accumulation in volcanic soils. The total Hg ranged from 3.0 to 640 ng g{sup -1} and it tended to diminish with soil depth except in some soils where the lithological discontinuities resulted in high values of Hg{sub T} in the Bw horizons. More than 75% of the Hg{sub T} variance could be attributed to distinct contents of organic matter, Al- and Fe-humus complexes and inorganic non-crystalline Al and Fe compounds in ''andic'', ''vitric'' and ''non-andic'' horizons. The degree of pedogenetic soil evolution notably influenced the Hg{sub T} soil content. Lithogenic Hg (1.6-320 ng g{sup -1}) was correlated with Al-humus complexes and clay content, suggesting the relevance of pedogenetic processes, whereas exogenic Hg (1.4-180 ng g{sup -1}) was correlated

  8. Disentangling above- and below-ground facilitation drivers in arid environments: the role of soil microorganisms, soil properties and microhabitat.

    Science.gov (United States)

    Lozano, Yudi M; Armas, Cristina; Hortal, Sara; Casanoves, Fernando; Pugnaire, Francisco I

    2017-12-01

    Nurse plants promote establishment of other plant species by buffering climate extremes and improving soil properties. Soil biota plays an important role, but an analysis to disentangle the effects of soil microorganisms, soil properties and microclimate on facilitation is lacking. In three microhabitats (gaps, small and large Retama shrubs), we placed six microcosms with sterilized soil, two per soil origin (i.e. from each microhabitat). One in every pair received an alive, and the other a sterile, inoculum from its own soil. Seeds of annual plants were sown into the microcosms. Germination, survival and biomass were monitored. Soil bacterial communities were characterized by pyrosequencing. Germination in living Retama inoculum was nearly double that of germination in sterile inoculum. Germination was greater under Retama canopies than in gaps. Biomass was up to three times higher in nurse than in gap soils. Soil microorganisms, soil properties and microclimate showed a range of positive to negative effects on understory plants depending on species identity and life stage. Nurse soil microorganisms promoted germination, but the effect was smaller than the positive effects of soil properties and microclimate under nurses. Nurse below-ground environment (soil properties and microorganisms) promoted plant growth and survival more than nurse microhabitat. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  9. Spatial correlation between weed species densities and soil properties

    DEFF Research Database (Denmark)

    Walter, Mette; Christensen, Svend; Simmelsgaard, Svend Erik

    2002-01-01

    The spatial cross-correlation between weed species densities and six soil properties within fields was analysed using cross-semivariograms. The survey was carried out in three successive years in two fields. The most consistent relationship between weed species density (numbers m−2) and soil...... properties was negative cross-correlation between the density of Viola arvensis Murray and clay content. This correlation was found in both fields; however, the range of spatial dependence varied between fields. In one of the fields, the density of Lamium purpureum L. was positively cross......-correlated with the phosphorus content in the soil in all years. The density of Veronica spp. and Poa annua L. was negatively cross-correlated with pH in all three years. Other spatial cross-correlations that were found in this study were inconsistent over time or field site. The densities of some of the weed species were...

  10. Neutron probe measurement of soil water content close to soil surface

    International Nuclear Information System (INIS)

    Faleiros, M.C.; Ravelo S, A.; Souza, M.D. de

    1993-01-01

    The problem of neutron probe soil water content measurements close to soil surface is analysed from the spatial variability and also from the slow neutron loss to the atmosphere points of view. Results obtained on a dark red latosol of the county of Piracicaba, SP, indicate the possibility of precisely measuring the neutron sphere of influence when different media are used on soil surface. (author). 7 refs, 5 figs, 1 tab

  11. Micrometeorological methods for measurements of mercury emissions over contaminated soils

    International Nuclear Information System (INIS)

    Kim, K.H.; Lindberg, S.E.; Hanson, P.J.; Owens, J.; Myers, T.P.

    1993-01-01

    As part of a larger study involving development and application of field and laboratory methods (micrometeorological, dynamic enclosure chamber, and controlled laboratory chamber methods) to measure the air/surface exchange of Hg vapor, we performed a series of preliminary measurements over contaminated soils. From March--April 1993, we used the modified Bowen ratio (MBR) method to measure emission rates of mercury over a floodplain contaminated with mercury near Oak Ridge, TN. The mercury emission rates measured from contaminated EFPC soils using the MBR method during early spring show that (1) in all cases, the contaminated soils acted as a source of mercury to the atmosphere with source strengths ranging from 17 to 160 ng m -2 h -1 ; and (2) the strengths of mercury emissions can be greatly influenced by the combined effects of surface soil temperature, residence time of air masses over the source area, and turbulence conditions. The mercury fluxes measured in a controlled flow chamber indicate that contaminated soils can exhibit up to an order of magnitude higher emission rates of Hg under conditions of elevated soil temperature, soil structure disturbance, and high turbulence. Mercury emissions from contaminated soils exceeded emissions from background soils by one to two orders of magnitude

  12. Effects of native forest restoration on soil hydraulic properties, Auwahi, Maui, Hawaiian Islands

    Science.gov (United States)

    Perkins, Kimberlie S.; Nimmo, John R.; Medeiros, Arthur C.

    2012-01-01

    Over historic time Hawai'i's dryland forests have been largely replaced by grasslands for grazing livestock. On-going efforts have been undertaken to restore dryland forests to bring back native species and reduce erosion. The reestablishment of native ecosystems on land severely degraded by long-term alternative use requires reversal of the impacts of erosion, organic-matter loss, and soil structural damage on soil hydraulic properties. This issue is perhaps especially critical in dryland forests where the soil must facilitate native plants' optimal use of limited water. These reforestation efforts depend on restoring soil ecological function, including soil hydraulic properties. We hypothesized that reforestation can measurably change soil hydraulic properties over restoration timescales. At a site on the island of Maui (Hawai'i, USA), we measured infiltration capacity, hydrophobicity, and abundance of preferential flow channels in a deforested grassland and in an adjacent area where active reforestation has been going on for fourteen years. Compared to the nearby deforested rangeland, mean field-saturated hydraulic conductivity in the newly restored forest measured by 55 infiltrometer tests was greater by a factor of 2.0. Hydrophobicity on an 8-point scale increased from average category 6.0 to 6.9. A 4-point empirical categorization of preferentiality in subsurface wetting patterns increased from an average 1.3 in grasslands to 2.6 in the restored forest. All of these changes act to distribute infiltrated water faster and deeper, as appropriate for native plant needs. This study indicates that vegetation restoration can lead to ecohydrologically important changes in soil hydraulic properties over decadal time scales.

  13. Effect of vegetation switch on soil chemical properties

    Czech Academy of Sciences Publication Activity Database

    Iwashima, N.; Masunaga, T.; Fujimaki, R.; Toyota, Ayu; Tayasu, I.; Hiura, T.; Kaneko, N.

    2012-01-01

    Roč. 58, č. 6 (2012), s. 783-792 ISSN 0038-0768 Institutional support: RVO:60077344 Keywords : earthworm * litter * nutrient cycling * soil chemical properties * vegetation switch Subject RIV: EH - Ecology, Behaviour Impact factor: 0.889, year: 2012

  14. Soil Properties And Pavement Performance In The Nigerian ...

    African Journals Online (AJOL)

    The geotechnical properties of the sub-structure of the Shagamu-Ore-Benin pavement were studied in an attempt to identifying the quality of construction materials and the pavement performance. The sub-structure soil materials were collected from the field and were taken to the laboratory for particle size analysis, Atterberg ...

  15. Heavy Metals and Physicochemical Properties of Soils in Kano ...

    African Journals Online (AJOL)

    and such soil properties as organic carbon, available P, total N and basic cations on the other. Keywords: ..... addition through fertilizers and agro-chemicals, their ..... Analysis of Fish Tissue for Trace Metals. Afon ... Nutrition 7(2): 244-248.

  16. Effect of animal manures on soil properties, growth, nutrients status ...

    African Journals Online (AJOL)

    A comparative field study was carried out at two sites in Akure, Southwest Nigeria to determine effect of different animal manures on soil physical and chemical properties and performance of tomato (Lycopersicm esculentus Mill). Analysis of cattle (CM), goat (GM), pig (PG) and poultry (PM) manures showed that N, K, Ca ...

  17. IMPACT OF MARBLE MINING ON SOIL PROPERTIES IN A PART ...

    African Journals Online (AJOL)

    Dr Osondu

    Ethiopian Journal of Environmental Studies and Management Vol. 4 No.2 2011 ... The effects of marble mining activities on the properties of soils of Igbeti marble area, Oke-Ogun,. Southwestern Nigeria .... 45´ and 4º 15´E in Olorunsogo Local.

  18. Tillage effects on soil. Physical properties and sunflower ...

    African Journals Online (AJOL)

    Soil physical properties and sunflower (Helianthus annuus) yield under convectional tillage (CT) and zero-tillage (Z,TJ. was monitored for 3 consecutive years in Ilorin, Southern Guinea Savannah zone of Nigeria (SGSZN). While bulk density of CT increased slightly over the years, significant decrease of 12 and 8% were ...

  19. Anti-fungal properties of chitinolytic dune soil bacteria

    NARCIS (Netherlands)

    De Boer, W.; Klein Gunnewiek, P.J.A.; Lafeber, P.; Janse, J.H.; Spit, B.E.; Woldendorp, J.W.

    1998-01-01

    Anti-fungal properties of chitinolytic soil bacteria may enable them to compete successfully for chitin with fungi. Additionally, the production of chitinase may be part of a lytic system that enables the bacteria to use living hyphae rather than chitin as the actual growth substrate, since chitin

  20. Relevance Vector Machine for Prediction of Soil Properties | Samui ...

    African Journals Online (AJOL)

    One of the first, most important steps in geotechnical engineering is site characterization. The ultimate goal of site characterization is to predict the in-situ soil properties at any half-space point for a site based on limited number of tests and data. In the present study, relevance vector machine (RVM) has been used to develop ...

  1. Mechanical properties of clayey soils and thermal solicitations

    International Nuclear Information System (INIS)

    Boisson, J.Y.

    1992-01-01

    Changes in permeability and mechanical properties of three clayey soils with temperature have been studied by using a special oedometric cell. The action of a thermal solicitation on the fabric and the behavior of the samples is highlighted. 3 figs., 1 tab

  2. Effect of biochar on soil properties and lead (Pb) availability in a ...

    African Journals Online (AJOL)

    jan

    Soil sample was collected from military camp of Jimma .... Physicochemical properties of soil sample and the soil-biochar mixture. The particle size ..... Elements uptake by metal ... solidification/stabilization of hazardous, radioactive, and mixed.

  3. Linking hydraulic properties of fire-affected soils to infiltration and water repellency

    Science.gov (United States)

    Moody, John A.; Kinner, David A.; Úbeda, Xavier

    2009-12-01

    SummaryHeat from wildfires can produce a two-layer system composed of extremely dry soil covered by a layer of ash, which when subjected to rainfall, may produce extreme floods. To understand the soil physics controlling runoff for these initial conditions, we used a small, portable disk infiltrometer to measure two hydraulic properties: (1) near-saturated hydraulic conductivity, K f and (2) sorptivity, S( θ i), as a function of initial soil moisture content, θ i, ranging from extremely dry conditions ( θ i ash, reference soils, soils unaffected by fire, and fire-affected soils. Each has a different degrees of water repellency that influences K f and S( θ i). Values of K f ranged from 4.5 × 10 -3 to 53 × 10 -3 cm s -1 for ash; from 0.93 × 10 -3 to 130 × 10 -3 cm s -1 for reference soils; and from 0.86 × 10 -3 to 3.0 × 10 -3 cm s -1, for soil unaffected by fire, which had the lowest values of K f. Measurements indicated that S( θ i) could be represented by an empirical non-linear function of θ i with a sorptivity maximum of 0.18-0.20 cm s -0.5, between 0.03 and 0.08 cm 3 cm -3. This functional form differs from the monotonically decreasing non-linear functions often used to represent S( θ i) for rainfall-runoff modeling. The sorptivity maximum may represent the combined effects of gravity, capillarity, and adsorption in a transitional domain corresponding to extremely dry soil, and moreover, it may explain the observed non-linear behavior, and the critical soil-moisture threshold of water repellent soils. Laboratory measurements of K f and S( θ i) are the first for ash and fire-affected soil, but additional measurements are needed of these hydraulic properties for in situ fire-affected soils. They provide insight into water repellency behavior and infiltration under extremely dry conditions. Most importantly, they indicate how existing rainfall-runoff models can be modified to accommodate a possible two-layer system in extremely dry conditions. These

  4. Measuring Low Concentrations of Liquid Water in Soil

    Science.gov (United States)

    Buehler, Martin

    2009-01-01

    An apparatus has been developed for measuring the low concentrations of liquid water and ice in relatively dry soil samples. Designed as a prototype of instruments for measuring the liquidwater and ice contents of Lunar and Martian soils, the apparatus could also be applied similarly to terrestrial desert soils and sands. The apparatus is a special-purpose impedance spectrometer: Its design is based on the fact that the electrical behavior of a typical soil sample is well approximated by a network of resistors and capacitors in which resistances decrease and capacitances increase (and, hence, the magnitude of impedance decreases) with increasing water content.

  5. Trends in soil-vegetation dynamics in burned Mediterranean pine forests: the effects of soil properties

    Science.gov (United States)

    Wittenberg, L.; Malkinson, D.

    2009-04-01

    Fire can impact a variety of soil physical and chemical properties. These changes may result, given the fire severity and the local conditions, in decreased infiltration and increased runoff and erosion rates. Most of these changes are caused by complex interactions among eco-geomorphic processes which affect, in turn, the rehabilitation dynamics of the soil and the regeneration of the burnt vegetation. Following wildfire events in two forests growing on different soil types, we investigated runoff, erosion, nutrient export (specifically nitrogen and phosphorous) and vegetation recovery dynamics. The Biriya forest site, burned during the 2006 summer, is composed of two dominant lithological types: soft chalk and marl which are relatively impermeable. The rocks are usually overlain by relatively thick, up of to 80 cm, grayish-white Rendzina soil, which contains large amounts of dissolved carbonate. These carbonates serve as a limiting factor for vegetation growth. The planted forest in Biriya is comprised of monospecific stands of Pinus spp. and Cupressus spp. The Mt. Carmel area, which was last burned in the 2005 spring, represents a system of varied Mediterranean landscapes, differentiated by lithology, soils and vegetation. Lithology is mainly composed of limestone, dolomite, and chalk. The dominant soil is Brown Rendzina whilst in some locations Grey Rendzina and Terra Rossa can be found. The local vegetation is composed mainly of a complex of pine (Pinus halepensis), oak (Quercus calliprinos), Pistacia lentiscus and associations At each site several 3X3 m monitoring plots were established to collect runoff and sediment. In-plot vegetation changes were monitored by a sequence of aerial photographs captured using a 6 m pole-mounted camera. At the terra-rosa sites (Mt. Carmel) mean runoff coefficients were 2.18% during the first year after the fire and 1.6% in the second. Mean erosion rates also decreased, from 42 gr/m2 to 4 gr/m2. The recovering vegetation was

  6. Ecological effects of the Hayman Fire - Part 3: Soil properties, erosion, and implications for rehabilitation and aquatic ecosystems

    Science.gov (United States)

    Jan E. Cipra; Eugene F. Kelly; Lee MacDonald; John Norman

    2003-01-01

    This team was asked to address three questions regarding soil properties, erosion and sedimentation, and how aquatic and terrestrial ecosystems have responded or could respond to various land management options. We have used soil survey maps, burn severity maps, and digital elevation model (DEM) maps as primary map data. We used our own field measurements and...

  7. Effect of various tillage practices on soil properties and maize growth

    International Nuclear Information System (INIS)

    Leghari, N.

    2016-01-01

    Appropriate tillage practices are vital for good tilth that is pre-requisite for aggregate formation, soil aeration, better root development and plant growth. A field experiment of maize was carried out at the experimental site of Sindh Agriculture University Tandojam during two consecutive growing seasons 2009 and 2010. A randomized complete block design with three treatment conventional tillage (CT), reduced tillage (RT) and no tillage (NT) was used in the study. Significant differences between tillage treatments were observed in the soil properties, growth and root development of plants. The NT treatment retained higher soil water contents (15.8 and 16.0%) measured at 0-20 cm depth during 2009 and 2010, respectively. Likewise, the soil bulk density (1.4 and 1.4 cm-3) was higher at this depth consequently; it resulted in greater soil strength (81 N m-2 and 79 N m-2) during 2009 and 2010, respectively. The negative and significant correlations were recorded between root dry weight and soil strengths. On the other hand, positive and significant relationship of root dry weight with mean total dry matter production and LAI was observed. Moreover, the root development related observations were significantly enhanced under CT as compared to RT and NT treatments. The results indicate that conventional tillage improve maize growth and root development by improving soil properties. (author)

  8. Interactions between leaf macro, micronutrients and soil properties in pistachio (Pistacia vera L.) orchards

    OpenAIRE

    Koukoulakis, Prodromos; Chatzissavvidis, Christos; Papadopoulos, Aristotelis; Pontikis, Dimitrios

    2013-01-01

    The interactions between: (i) leaf dry matter macronutrients, micronutrients and soil chemical properties, (ii) leaf macro- and micronutrients, (iii) soil macro- and micronutrients and (iv) soil chemical properties, and soil micro- and macronutrients in 50 pistachio orchards were investigated in leaves and soils by means of regression analysis. Most of the soils were deficient in plant-available P, Zn, Mn, Fe, and B, while they were excessively supplied with Cu. Leaf analysis showed that most...

  9. Effects of Biochar and Lime on Soil Physicochemical Properties and Tobacco Seedling Growth in Red Soil

    Directory of Open Access Journals (Sweden)

    ZHU Pan

    2015-12-01

    Full Text Available Red soil, mainly found in the southern China, is developed in a warm, moist climate. The main property of the soils is strong acidity, aluminum toxicity, and low available nutrients. In this study, different effects of biochar and lime on soil physicochemical properties and tobacco growth were determined in red soil, so as to provide a scientific foundation for soil improvement tobacco field. A pot experiment was designed and conducted at four biochar levels(0, 0.5%, 1%, 2% and normal lime level (0.3% to study effects of two different soil amendments on red soil pH, exchangeable aluminum(Exc-Al and exchangeable manganese(Exc-Mn, available nutrients and organic carbon (SOC. Meanwhile, agronomic traits, biomass and leaves elements of tobacco were also tested. Results showed that the agronomic characters and biomass of tobacco seedling had changed effectively after biochar or lime was added. Under 0.5%, 1% biochar treatment, the content of nitrogen(N, phosphorus(P, potassium(K, calcium(Ca and magnesium(Mg in tobacco leaves substantially raised. However, when 2% biochar was applied, leaves N content declined by 9.3%. Compared with the control, leaves N, P and Ca content increased observably in the lime treatment. However, its K and Mg content decreased by 9.0% and 13.3% respectively. Alkaline nitrogen(SAN, available phosphorus (SAP, available potassium (SAK, and exchangeable calcium (Exc-Ca and exchangeable magnesium (Exc-Mg were improved obviously in soil applied with biochar. Only the content of Exc-Ca was significantly increased in lime treatment. In addition, it was beneficial to improve soil pH and reduce soil Exc-Al when biochar or lime had been used. Thus, both biochar and lime are propitious to increase soil pH value, lessen soil Exc-Al content, and improve the growth of tobacco seedling. Furthermore, biochar application also can raise the content of available nutrient and SOC in red soil.

  10. Simulation of nitrous oxide effluxes, crop yields and soil physical properties using the LandscapeDNDC model in managed ecosystem

    Science.gov (United States)

    Nyckowiak, Jedrzej; Lesny, Jacek; Haas, Edwin; Juszczak, Radoslaw; Kiese, Ralf; Butterbach-Bahl, Klaus; Olejnik, Janusz

    2014-05-01

    Modeling of nitrous oxide emissions from soil is very complex. Many different biological and chemical processes take place in soils which determine the amount of emitted nitrous oxide. Additionaly, biogeochemical models contain many detailed factors which may determine fluxes and other simulated variables. We used the LandscapeDNDC model in order to simulate N2O emissions, crop yields and soil physical properties from mineral cultivated soils in Poland. Nitrous oxide emissions from soils were modeled for fields with winter wheat, winter rye, spring barley, triticale, potatoes and alfalfa crops. Simulations were carried out for the plots of the Brody arable experimental station of Poznan University of Life Science in western Poland and covered the period 2003 - 2012. The model accuracy and its efficiency was determined by comparing simulations result with measurements of nitrous oxide emissions (measured with static chambers) from about 40 field campaigns. N2O emissions are strongly dependent on temperature and soil water content, hence we compared also simulated soil temperature at 10cm depth and soil water content at the same depth with the daily measured values of these driving variables. We compared also simulated yield quantities for each individual experimental plots with yield quantities which were measured in the period 2003-2012. We conclude that the LandscapeDNDC model is capable to simulate soil N2O emissions, crop yields and physical properties of soil with satisfactorily good accuracy and efficiency.

  11. Spatial structure of soil properties at different scales of Mt. Kilimanjaro, Tanzania

    Science.gov (United States)

    Kühnel, Anna; Huwe, Bernd

    2013-04-01

    Soils of tropical mountain ecosystems provide important ecosystem services like water and carbon storage, water filtration and erosion control. As these ecosystems are threatened by global warming and the conversion of natural to human-modified landscapes, it is important to understand the implications of these changes. Within the DFG Research Unit "Kilimanjaro ecosystems under global change: Linking biodiversity, biotic interactions and biogeochemical ecosystem processes", we study the spatial heterogeneity of soils and the available water capacity for different land use systems. In the savannah zone of Mt. Kilimanjaro, maize fields are compared to natural savannah ecosystems. In the lower montane forest zone, coffee plantations, traditional home gardens, grasslands and natural forests are studied. We characterize the soils with respect to soil hydrology, emphasizing on the spatial variability of soil texture and bulk density at different scales. Furthermore soil organic carbon and nitrogen, cation exchange capacity and the pH-value are measured. Vis/Nir-Spectroscopy is used to detect small scale physical and chemical heterogeneity within soil profiles, as well as to get information of soil properties on a larger scale. We aim to build a spectral database for these soil properties for the Kilimanjaro region in order to get rapid information for geostatistical analysis. Partial least square regression with leave one out cross validation is used for model calibration. Results for silt and clay content, as well as carbon and nitrogen content are promising, with adjusted R² ranging from 0.70 for silt to 0.86 for nitrogen. Furthermore models for other nutrients, cation exchange capacity and available water capacity will be calibrated. We compare heterogeneity within and across the different ecosystems and state that spatial structure characteristics and complexity patterns in soil parameters can be quantitatively related to biodiversity and functional diversity

  12. Effect of sewage sludge hydrochar on soil properties and Cd immobilization in a contaminated soil.

    Science.gov (United States)

    Ren, Jie; Wang, Fenghua; Zhai, Yunbo; Zhu, Yun; Peng, Chuan; Wang, Tengfei; Li, Caiting; Zeng, Guangming

    2017-12-01

    To investigate hydrochar as a soil amendment for the immobilization of Cd, the characteristics of hydrochars (HCs) under three temperatures and residence times, were studied, with a particular interest in soil properties, as well as the speciation, availability and plant uptake of Cd. HCs were obtained by a hydrothermal carbonization (HTC) reaction of sewage sludge (SS). Based on the study of HC properties, we found that HCs present weak acidity with relatively high ash content and low electrical conductivity (EC) values. The addition of HCs to soil decreased soil pH and EC values but increased the abundance of soil microorganism. HCs also promoted the transformation of Cd from unstable to stable speciation and can decrease the content of phyto-available Cd (optimum condition and efficiency: A13, 2 15.38%), which restrained cabbage from assimilating Cd from soil both the aboveground (optimum condition and efficiency: A35, 52.29%) and underground (optimum condition and efficiency: C15, 57.53%) parts of it. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Use of Ultrasonic Technology for Soil Moisture Measurement

    Science.gov (United States)

    Choi, J.; Metzl, R.; Aggarwal, M. D.; Belisle, W.; Coleman, T.

    1997-01-01

    In an effort to improve existing soil moisture measurement techniques or find new techniques using physics principles, a new technique is presented in this paper using ultrasonic techniques. It has been found that ultrasonic velocity changes as the moisture content changes. Preliminary values of velocities are 676.1 m/s in dry soil and 356.8 m/s in 100% moist soils. Intermediate values can be calibrated to give exact values for the moisture content in an unknown sample.

  14. Mechanical Properties of Millet Husk Ash Bitumen Stabilized Soil Block

    Directory of Open Access Journals (Sweden)

    M. T. Abdulwahab

    2017-06-01

    Full Text Available This study presents an investigation into the improvement of strength and durability properties of lateritic soil blocks using Millet Husk Ash (MHA and Bitumen as additives so as to reduce its high cost and find alternative disposal method for agricultural waste. The lateritic soil samples were selected and treated with 0%, 10%, 15%, 20%, 30%, 40% and 50% of MHA by weight of laterite. The lateritic soil-MHA mixture was later admixed with 0%, 2%, 4%, 6%, 8%, 10%, 12% and 14% cut-back bitumen solution by weight of laterite. Both the natural lateritic soil, lateritic and MHA, and the blend of Soil, MHA and Bitumen were first subjected to physical and chemical analysis using X-Ray Fluorescence (XRF and Scanning Electromagnetic Machine (SEM to determine their engineering properties followed by the performance test on bricks cast with varying quantities of the additives. A total of one hundred and ninety two (192 cubes were tested for moisture absorption, erodability and compressive strength tests. The result of the test showed that MHA and Bitumen acted as pozzolana in performance test on the soil blocks. Up to 30% MHA – laterite and 20% MHA admixed with 8% laterite were found to give optimum compressive strength of 10.8N/mm2 and 10.9N/mm2 for the bricks produced. The result also showed that about 50% MHA blended with 14% Bitumen solution ensured water tight bricks. Thus the use of MHA as partial replacement of cement will provide an economic use of by-product and consequently produce a cheaper soil block construction without comprising its strength.

  15. Sensing soil properties in the laboratory, in situ, and on-Line: A review

    NARCIS (Netherlands)

    Kuang, B.; Mahmood, H.S.; Quraishi, Z.; Hoogmoed, W.B.; Mouazen, A.M.; Henten, van E.

    2012-01-01

    Since both the spatial and vertical heterogeneities in soil properties have an impact on crop growth and yield, accurate characterization of soil properties at high sampling resolution is a preliminary step in successful management of soil-water-plant system. Conventional soil sampling and analyses

  16. Hydraulic properties of alluvial soil of the ebb tide of Flocos Dam in Tuparetama - Pernambuco State, Brazil

    International Nuclear Information System (INIS)

    Souza, Eduardo S.; Montenegro, Abelardo A.A.

    2000-01-01

    The soil hydraulic properties, i.e., the soil-moisture characteristic curve, Θ(h), and the hydraulic conductivity, K(h), were determined for an alluvial soil from Flocos Dam, located at Tuparetama, state of Pernambuco, Brazil. The soil characteristic curves were determined through the functional adjustment, proposed by van Genuchten, to the values obtained in field measurements with tensiometers and neutron probes, and to values obtained in laboratory in a 'pressure pan' with a porous plate. The infiltration tests were performed for the depths of 0, 20, 40, 60, and 80 cm using an infiltration disk with a diameter of 80 mm, applying water at a potential of 0, -3, -6 and -12 cm. The hydraulic conductivity of the soil was determined through the VG method proposed by Zhang, which requires the previous knowledge of the soil-moisture characteristic curve. The determination of the soil-moisture characteristic curve by the two methods, using field or laboratory measurements, yielded similar results within the range of common pressure, from -300 to -100 cm, and indicates that the experimental results are sound and coherent. The heterogeneity of soil hydraulic properties within the soil profile can be explained by the variability in soil texture and dry bulk density throughout the profile. By using the diameter of the infiltration disk and the pressure applied to the soil, it was possible to characterize the porous matrix within the clayey layer. (author)

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

    Science.gov (United States)

    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

  18. Relationship Between Physical Properties and Magnetism of Soils From Various Pedoenvironments

    Science.gov (United States)

    Jordanova, N.; Jordanova, D.; Todorova, D.; Hirt, A.; Petrov, P.

    2009-05-01

    Characterization of soils with respect to their fertility, sustainable use and conservation require extensive, time- consuming and costly analyses. Establishment of well defined relationships between certain physical, geochemical and magnetic parameters would be useful tool in pedometrics, giving opportunity to carry out large scale studies on soil properties in more economically effective and fast way. Interdisciplinary analysis of 15 type soils from different pedoenvironments (oxidative, water-logged, salty, etc.) includes extensive magnetic measurements (magnetic susceptibility, anhysteretic (ARM) and isothermal (IRM) remanences, hysteresis parameters); determination of a set of physical characteristics (grain size fractions, pH) and geochemical analyses (total Fe content, oxalate- and dithionite-soluble Fe). Empirical linear relationship is found between soil reaction (pH) and magnetic susceptibility for aerobic soils, and negative relationship between pH and ARM for water-logged soils. Different type soils, showing magnetic enhancement along the solum, show higher ARM intensity with increasing percent of the clay fraction. This feature most probably is related to the fact that pedogenic ferrimagnetic minerals are strongly linked to clay fraction. The absence of such correlation for soils, affected by water-logging conditions suggests prevailing role of amorphous phases and antiferromagnetic Fe oxides in magnetic mineralogy. The role of pedogenic factors for particular behavior of other magnetic parameters will be discussed.

  19. Effects of plough pan development on surface hydrology and on soil physical properties in Southeastern Brazilian plateau

    Science.gov (United States)

    Bertolino, Ana V. F. A.; Fernandes, Nelson F.; Miranda, João P. L.; Souza, Andréa P.; Lopes, Marcel R. S.; Palmieri, Francesco

    2010-10-01

    SummaryConventional tillage may impose changes in soil physical properties that lead to a decrease in soil physical quality. Although plough pan formation is considered to be an important consequence of conventional tillage practices in Southeastern Brazil, few studies have focused on its hydrological consequences. Detailed investigations in two experimental plots located in the hilly landscape of Serra do Mar close to Rio de Janeiro city were carried out to characterize the changes in soil physical properties and in soil hydrology due to plough pan formation. Conventional (CT) and minimum tillage (MT) practices were implemented in two plots for 3 years and soil matric potential (SMP) was monitored in each plot via nests of tensiometers and Watermark® sensors installed at different depths. Undisturbed soil blocks were collected for micromorphological analyses to quantify the total pore space in soils under CT and MT systems, and in soils under natural tropical forest. Results suggest that soils under the CT system developed a plough pan layer at about 20 cm depth that had 44% less total porosity as compared to surface conditions. It is shown that soils under the CT system tended to stay saturated for longer periods of time after each rainfall event. Besides, during intense rainy periods soils under the CT system may develop hydrologic conditions that favor lateral flows while soils under the MT system were still draining. Such hydrological responses may explain why average soil erosion rates measured for individual rainfall events under the CT system were about 2.5 times greater than the ones observed at MT. The results attested that conventional tillage in this area generated modifications in soil fabric, especially in pore-size distribution and connectivity, which induced important changes in soil hydrology and soil erosion. The agricultural practices used in this area, associated with the local steep hillslopes and intense rainfall events, are definitely not

  20. THEORETICAL PRINCIPLES OF EVALUATION OF EFFICIENCY OF SOIL CONSERVATION MEASURES IN AGRICULTURAL LAND-USE

    Directory of Open Access Journals (Sweden)

    Shevchenko O.

    2017-08-01

    Full Text Available In the article modern scientific and theoretical positions concerning determination of the effectiveness of soil protection measures on agricultural lands are investigated. It is analyzed that the protection of land from degradation is one of the most important problems of agriculture, as this process leads to a significant decrease in soil fertility and crop yields. That is why in today's conditions, when the protection of agricultural land became urgent and a priority task, the scientific substantiation of the economic assessment of the damage caused by the degradation of land to agriculture, as well as the development of methods for determining the economic efficiency of the most progressive soil protection measures, technologies and complexes based on their overall Comparative evaluation. It was established that ground protection measures are a system of various measures aimed at reducing the negative degradation effect on the soil cover and ensuring the preservation and reproduction of soil fertility and integrity, as well as increasing their productivity as a result of rational use. The economic essence of soil protection measures is the economic effect achieved by preventing damage caused by land degradation to agriculture, as well as for obtaining additional profit as a result of their action. The economic effectiveness of soil protection measures means their effectiveness, that is, the correlation between the results and the costs that they provided. The excess of the economic result over the cost of its achievement indicates the economic efficiency of soil protection measures, and the difference between the result and the expenditure characterizes the economic effect. Ecological efficiency is characterized by environmental parameters of the soil cover, namely: the weakening of degradation effects on soils; improvement of their qualitative properties; An increase in production without violation of environmental standards, etc. Economic

  1. Adaptive Surface Modeling of Soil Properties in Complex Landforms

    Directory of Open Access Journals (Sweden)

    Wei Liu

    2017-06-01

    Full Text Available Abstract: Spatial discontinuity often causes poor accuracy when a single model is used for the surface modeling of soil properties in complex geomorphic areas. Here we present a method for adaptive surface modeling of combined secondary variables to improve prediction accuracy during the interpolation of soil properties (ASM-SP. Using various secondary variables and multiple base interpolation models, ASM-SP was used to interpolate soil K+ in a typical complex geomorphic area (Qinghai Lake Basin, China. Five methods, including inverse distance weighting (IDW, ordinary kriging (OK, and OK combined with different secondary variables (e.g., OK-Landuse, OK-Geology, and OK-Soil, were used to validate the proposed method. The mean error (ME, mean absolute error (MAE, root mean square error (RMSE, mean relative error (MRE, and accuracy (AC were used as evaluation indicators. Results showed that: (1 The OK interpolation result is spatially smooth and has a weak bull's-eye effect, and the IDW has a stronger ‘bull’s-eye’ effect, relatively. They both have obvious deficiencies in depicting spatial variability of soil K+. (2 The methods incorporating combinations of different secondary variables (e.g., ASM-SP, OK-Landuse, OK-Geology, and OK-Soil were associated with lower estimation bias. Compared with IDW, OK, OK-Landuse, OK-Geology, and OK-Soil, the accuracy of ASM-SP increased by 13.63%, 10.85%, 9.98%, 8.32%, and 7.66%, respectively. Furthermore, ASM-SP was more stable, with lower MEs, MAEs, RMSEs, and MREs. (3 ASM-SP presents more details than others in the abrupt boundary, which can render the result consistent with the true secondary variables. In conclusion, ASM-SP can not only consider the nonlinear relationship between secondary variables and soil properties, but can also adaptively combine the advantages of multiple models, which contributes to making the spatial interpolation of soil K+ more reasonable.

  2. Soil science basis and the effect of oil contamination on chemical properties of soils

    International Nuclear Information System (INIS)

    Wagner, A.; Miehlich, G.

    1993-01-01

    The changes in soil chemistry properties due to oil contamination and decontamination are examined. One main point of the work is the determination of the effect of oil on the availability of nutrients in the soil. Nutrients are not only present dissolved in the soil solution, but are for the most part reversibly adsorbed by exchangers on loaded surfaces. The clay minerals, the organic substance and iron and manganese oxide act as exchangers. Knowledge on surface structure and reactions in soils contaminated by oil is to be obtained via examination of the exchange behaviour of different bio-elements. The results supply the basis for the cleaning up technique, the judgement of cleaned materials and their reusability. (orig.) [de

  3. Influence of long-term fertilization on soil physicochemical properties in a brown soil

    Science.gov (United States)

    Li, Dongdong; Luo, Peiyu; Han, Xiaori; Yang, Jinfeng

    2018-01-01

    This study aims to explore the influence on soil physicochemical properties under a 38-y long-term fertilization in a brown soil. Soil samples (0-20 cm)were taken from the six treatments of the long-term fertilization trial in October 2016:no fertilizer (CK), N1(mineral nitrogen fertilizer), N1P (mineral nitrogen and phosphate fertilizer), N1PK (mineral nitrogen, phosphate and potassic fertilizer), pig manure (M2), M2N1P (pig manure, mineral nitrogen and phosphate fertilizer).The results showed thatthe long-term application of chemical fertilizers reduced soil pH value, while the application of organic fertilizers increased pH value. Fertilization significantly increased the content of AHN, TN and SOM. Compared with the CK treatment and chemical fertilizer treatments, organic fertilizer treatments significantly increased the content of AP and TP. The content of AK and TK were no significant difference in different treatment.

  4. Quicklime-induced changes of soil properties: Implications for enhanced remediation of volatile chlorinated hydrocarbon contaminated soils via mechanical soil aeration.

    Science.gov (United States)

    Ma, Yan; Dong, Binbin; He, Xiaosong; Shi, Yi; Xu, Mingyue; He, Xuwen; Du, Xiaoming; Li, Fasheng

    2017-04-01

    Mechanical soil aeration is used for soil remediation at sites contaminated by volatile organic compounds. However, the effectiveness of the method is limited by low soil temperature, high soil moisture, and high soil viscosity. Combined with mechanical soil aeration, quicklime has a practical application value related to reinforcement remediation and to its action in the remediation of soil contaminated with volatile organic compounds. In this study, the target pollutant was trichloroethylene, which is a volatile chlorinated hydrocarbon pollutant commonly found in contaminated soils. A restoration experiment was carried out, using a set of mechanical soil-aeration simulation tests, by adding quicklime (mass ratios of 3, 10, and 20%) to the contaminated soil. The results clearly indicate that quicklime changed the physical properties of the soil, which affected the environmental behaviour of trichloroethylene in the soil. The addition of CaO increased soil temperature and reduced soil moisture to improve the mass transfer of trichloroethylene. In addition, it improved the macroporous cumulative pore volume and average pore size, which increased soil permeability. As soil pH increased, the clay mineral content in the soils decreased, the cation exchange capacity and the redox potential decreased, and the removal of trichloroethylene from the soil was enhanced to a certain extent. After the addition of quicklime, the functional group COO of soil organic matter could interact with calcium ions, which increased soil polarity and promoted the removal of trichloroethylene. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Measuring solvent barrier properties of paper

    International Nuclear Information System (INIS)

    Bollström, Roger; Saarinen, Jarkko J; Toivakka, Martti; Räty, Jukka

    2012-01-01

    New methods for measuring barrier properties against solvents, acids and bases on dispersion coated paper were developed and investigated. Usability, reliability and repeatability were compared both between the new methods and with the standardized method for measuring barrier properties against water vapor. Barrier properties could be measured with all methods and the results obtained by the different methods were in correlation with each other. A qualitative method based on a trace color provided an indicative result, whereas further developed methods also took into account the durability. The effective barrier lifetime could be measured by measuring the conductivity through the substrate as a function of time, or by utilizing a glass prism where the change in refractive index caused by penetrated liquid was monitored, also as a function of time. Barrier properties against water and humidity were also measured and were found not to be predictors for barrier properties against either solvents, or acids or bases, which supports the need to develop new methods

  6. Measurement of trifluralin volatilization in the field: Relation to soil residue and effect of soil incorporation

    International Nuclear Information System (INIS)

    Bedos, C.; Rousseau-Djabri, M.F.; Gabrielle, B.; Flura, D.; Durand, B.; Barriuso, E.; Cellier, P.

    2006-01-01

    Volatilization may represent a major dissipation pathway for pesticides applied to soils or crops. A field experiment (September, 2002), consisted in volatilization fluxes measurements during 6 days, covering the periods before and after soil incorporation carried out 24 h after trifluralin spraying on bare soil. Evolution of concentration in soil was measured during 101 days, together with soil physical and meteorological variables. Volatilization fluxes were very high immediately after application (1900 ng m -2 s -1 ), decreased down to 100 ng m -2 s -1 in the following 24 h. Soil incorporation strongly abated trifluralin concentration in the air. 99% of the total volatilization losses recorded over the 6 days following application occurred before incorporation. Volatilization fluxes evidenced a diurnal cycle driven by environmental conditions. Soil trifluralin residues could still be quantified 101 days after application. Our results highlight the caution required when using soil degradation half-life values in the field for volatile compounds. - Losses by volatilization contribute significantly to soil dissipation of the herbicide trifluralin before its soil incorporation

  7. Soil hydraulic properties of topsoil along two elevation transects affected by soil erosion

    Czech Academy of Sciences Publication Activity Database

    Nikodem, A.; Kodešová, R.; Jakšík, O.; Jirků, V.; Fér, M.; Klement, A.; Žigová, Anna

    2013-01-01

    Roč. 15, - (2013) ISSN 1607-7962. [EGU General Assembly /10./. 07.04.2013-12.04.2013, Vienna] Institutional support: RVO:67985831 Keywords : topsoil * hydraulic properties * erosion processes Subject RIV: DF - Soil Science http://meetingorganizer.copernicus.org/EGU2013/EGU2013-7924.pdf

  8. Effect of soil properties on Hydraulic characteristics under subsurface drip irrigation

    Science.gov (United States)

    Fan, Wangtao; Li, Gang

    2018-02-01

    Subsurface drip irrigation (SDI) is a technique that has a high potential in application because of its high efficiency in water-saving. The hydraulic characteristics of SDI sub-unit pipe network can be affected by soil physical properties as the emitters are buried in soils. The related research, however, is not fully explored. The laboratory tests were carried out in the present study to determine the effects of hydraulic factors including operating pressure, initial soil water content, and bulk density on flow rate and its sensitivity to each hydraulic factor for two types of SDI emitters (PLASSIM emitter and Heping emitter). For this purpose, three soils with contrasting textures (i.e., light sand, silt loam, and light clay) were repacked with two soil bulk density (1.25 and1.40 g cm-3) with two initial soil water content (12% and 18%) in plexiglass columns with 40 cm in diameter and 40 cm in height. Drip emitters were buried at depth of 20 cm to measure the flow rates under seven operating pressures (60, 100, 150, 200, 250, 300, and 370 kPa). We found that the operating pressure was the dominating factor of flow rate of the SDI emitter, and flow rate increased with the increase of operating pressure. The initial soil water content and bulk density also affected the flow rate, and their effects were the most notable in the light sand soil. The sensitivity of flow rate to each hydraulic factor was dependent on soil texture, and followed a descending order of light sand>silt loam>light clay for both types of emitters. Further, the sensitivity of flow rate to each hydraulic factor decreased with the increase of operating pressure, initial soil water content, and bulk density. This study may be used to guide the soil specific-design of SDI emitters for optimal water use and management.

  9. Carbon dioxide titration method for soil respiration measurements

    OpenAIRE

    Martín Rubio, Luis

    2017-01-01

    This thesis was commissioned by Tampere University of Applied Sciences, which was interested in studying and developing a titration measurement method for soil respiration and biodegradability. Some experiments were carried out measuring soil respiration for testing the method and others adding some biodegradable material like polylactic acid compressed material and 100% biodegradable plastic bags to test its biodegradability and the possibility to measure it via titration. The thesi...

  10. Petrophysical approach to electrical properties of loose soils

    Directory of Open Access Journals (Sweden)

    В. А. Шевнин

    2017-08-01

    Full Text Available The paper focuses on the relation between geoelectrical characteristics of the soil: resistivity, polarizability and normalized polarizability (ρ, η, Mn – and its superficial conductivity (SC or σ" using methods of vertical electrical sounding with induced polarization (VES-IP, electric profiling with induced polarization (EP-IP and frequency characteristic (FC-IP. The authors demonstrate that superficial conductivity can be determined not only from spectral IP data, but also from soil resistivity obtained through petrophysical measurements. In this case normalized polarizability (Mn is equal to superficial conductivity (SC. Superficial conductivity, in its turn, is proportionate to clay content of the soil. Increasing clayiness reduces hydraulic conductivity. It has been demonstrated that interpretation of EP-IP results benefits from combined study of the plots of three abovementioned parameters (ρ, η, Mn. In the aeration zone, incomplete humidity has a significant effect on geoelectrical parameters of the soil. Petrophysical modelling helps to investigate the impact of humidity.

  11. Soil hydraulic properties near saturation, an improved conductivity model

    DEFF Research Database (Denmark)

    Børgesen, Christen Duus; Jacobsen, Ole Hørbye; Hansen, Søren

    2006-01-01

    of commonly used hydraulic conductivity models and give suggestions for improved models. Water retention and near saturated and saturated hydraulic conductivity were measured for a variety of 81 top and subsoils. The hydraulic conductivity models by van Genuchten [van Genuchten, 1980. A closed-form equation...... for predicting the hydraulic conductivity of unsaturated soils. Soil Sci. Soc. Am. J. 44, 892–898.] (vGM) and Brooks and Corey, modified by Jarvis [Jarvis, 1991. MACRO—A Model of Water Movement and Solute Transport in Macroporous Soils. Swedish University of Agricultural Sciences. Department of Soil Sciences....... Optimising a matching factor (k0) improved the fit considerably whereas optimising the l-parameter in the vGM model improved the fit only slightly. The vGM was improved with an empirical scaling function to account for the rapid increase in conductivity near saturation. Using the improved models...

  12. Comparing measured with simulated vertical soil stress under vehicle load

    DEFF Research Database (Denmark)

    Keller, Thomas; Lamandé, Mathieu; Arvidsson, Johan

    The load transfer within agricultural soil is typically modelled on the basis of the theory of stress transmission in elastic media, usually in the semi-empirical form that includes the “concentration factor” (v). Measurements of stress in soil are needed to evaluate model calculations, but may...

  13. Estimating soil water evaporation using radar measurements

    Science.gov (United States)

    Sadeghi, Ali M.; Scott, H. D.; Waite, W. P.; Asrar, G.

    1988-01-01

    Field studies were conducted to evaluate the application of radar reflectivity as compared with the shortwave reflectivity (albedo) used in the Idso-Jackson equation for the estimation of daily evaporation under overcast sky and subhumid climatic conditions. Soil water content, water potential, shortwave and radar reflectivity, and soil and air temperatures were monitored during three soil drying cycles. The data from each cycle were used to calculate daily evaporation from the Idso-Jackson equation and from two other standard methods, the modified Penman and plane of zero-flux. All three methods resulted in similar estimates of evaporation under clear sky conditions; however, under overcast sky conditions, evaporation fluxes computed from the Idso-Jackson equation were consistently lower than the other two methods. The shortwave albedo values in the Idso-Jackson equation were then replaced with radar reflectivities and a new set of total daily evaporation fluxes were calculated. This resulted in a significant improvement in computed soil evaporation fluxes from the Idso-Jackson equation, and a better agreement between the three methods under overcast sky conditions.

  14. Measurement of K40 in mine soil

    International Nuclear Information System (INIS)

    Salazar R, A. R.; Vega C, H. R.

    2014-10-01

    The natural radioactivity of the soil and the external exposition of the gamma radiation mainly depend of the geologic characteristics of the same soil. Their radioactivity levels provide information of the radio-nuclides distribution in the environment and allow estimating the radiological risk. For this reason, the objective of this work was to determine the K 40 concentration in four soil samples of a mine that produces Ag, Pb, Cu, and Zn, in Zacatecas State (Mexico), through gamma rays spectrometry using a Sodium Iodide detector doped with Thallium (Nal (Tl)). The results it was found that the soil sample contaminated by the liquid effluents of the mine it has a specific activity of 353 Bq/kg, for draw Los Angeles of 55 Bq/kg, in the old dam of 307 Bq/kg and inside the mine of 485 Bq/kg, mentioning that all the sites refer to the same mine. Using a conversion factor of 0.043 n Gy/h (Bq/kg) -1 to calculate the absorbed dose in air of the natural radionuclide as the K 40 in the soil samples were founded the following dose reasons; of 15.18 n Gy/h, 2.37 n Gy/h, 13.2 n Gy/h and 20.86 n Gy/h, respectively. These results are similar to those reported for soil samples of Texas (USA), Karabuk (Turkey) and Kalpakkam (India), it should be noted that these samples are not mine samples; only were used like reference for this work. Our results are in an average of 300 Bq/kg that corresponds to one dose reason of 12.9 n Gy/h, comparing it with the highest value reported in the case of Chinese that is of 580 Bq/kg (24.94 n Gy/h) throwing a difference of 48.3% and compared with the smallest average value that belongs to Tripoli (Libya) of 270 Bq/kg (11.61 n Gy/h) is of 10%. The concentration average of the K 40 activity was below the world average of absorbed dose, which is of 55 n Gy/h of the average reported for the world, therefore these results can be used as a reference for the radioactivity analysis in the soil of this mine. (Author)

  15. Soil Stress-Strain Behavior: Measurement, Modeling and Analysis

    CERN Document Server

    Ling, Hoe I; Leshchinsky, Dov; Koseki, Junichi; A Collection of Papers of the Geotechnical Symposium in Rome

    2007-01-01

    This book is an outgrowth of the proceedings for the Geotechnical Symposium in Roma, which was held on March 16 and 17, 2006 in Rome, Italy. The Symposium was organized to celebrate the 60th birthday of Prof. Tatsuoka as well as honoring his research achievement. The publications are focused on the recent developments in the stress-strain behavior of geomaterials, with an emphasis on laboratory measurements, soil constitutive modeling and behavior of soil structures (such as reinforced soils, piles and slopes). The latest advancement in the field, such as the rate effect and dynamic behavior of both clay and sand, behavior of modified soils and soil mixtures, and soil liquefaction are addressed. A special keynote paper by Prof. Tatsuoka is included with three other keynote papers (presented by Prof. Lo Presti, Prof. Di Benedetto, and Prof. Shibuya).

  16. SOILS AGROCHEMICAL PROPERTIES VARIATION UNDER MEDICINAL HERBS ECOLOGICAL CROPS

    Directory of Open Access Journals (Sweden)

    Mihaela Lungu

    2012-12-01

    Full Text Available Researches have been carried out with medicinal herbs in the frame of a National project financed by CNCSIS through the Partnership Program. Ecologic and conventional technologies were applied. The project aimed to implement a standardization system of the vegetal raw materials which can be used in the cosmetic industry. Sage, basilicum, and savory were subject of the experiments, at Jucu, Cluj County, Ungureni – Butimanu, Dâmboviţa County, and Secuieni, Neamţ County. The dominant soils in these areas are Fluvisols and Haplic Chernozems in the Jucu area, Chromic Luvisol in the Ungureni – Butimanu area, and Calcic Chernozem in the Secuieni area. The agrochemical analysis of the soils from the experimental fields highlighted soil fertility properties conservation both under ecologic and conventional growing technologies.

  17. Mitigation measures for soil embankments against fault rupture using geosynthetics

    DEFF Research Database (Denmark)

    Zania, Varvara; Tsompanakis, Yiannis; Psarropoulos, Prodromos

    2010-01-01

    , the number of the reinforcements, the height of the soil layer and the applied fault displacement was examined. The results which were obtained from this investigation indicate that the proposed configurations of reinforced soil can be efficiently used in order to reduce the permanent deformations developed......In the current study the ability of geosynthetics to reduce the permanent deformations developed due to a fault rupture propagation in a soil embankment is investigated. For this purpose parametric numerical analyses were performed and the effect of the material properties of the geosynthetics...

  18. Transport properties and pore-network structure in variably-saturated Sphagnum peat soil

    DEFF Research Database (Denmark)

    Hamamoto, Shoichiro; Dissanayaka, Shiromi Himalika; Kawamoto, K.

    2016-01-01

    Gas and water transport in peat soil are of increasing interest because of their potentially large environmental and climatic effects under different types of land use. In this research, the water retention curve (WRC), gas diffusion coefficient (Dg) and air and water permeabilities (ka and kw......) of layers in peat soil from two profiles were measured under different moisture conditions. A two-region Archie's Law (2RAL)-type model was applied successfully to the four properties; the reference point was taken at -9.8kPa of soil-water matric potential where volume shrinkage typically started to occur....... For WRC in the very decomposed peat soil, the 2RAL saturation exponents (n) obtained for both the wetter (nw) and drier regions (nd) were smaller than those for the less decomposed peat. For Dg, the saturation exponent in the wetter region was larger than that in the drier one for all layers, which...

  19. Soil-to-plant transfer factors for radiocaesium measured in different soil types in the Czech Republic

    International Nuclear Information System (INIS)

    Tecl, J.; Mirchi, R.; Malatova, I.; Peskova, I.; Schlesingerova, E.

    2001-01-01

    This study was perform in frame of the SAVEC project (SAVEC = Spatial Analysis of Vulnerable Ecosystems in Central Europe; European Union project). The aim of the SAVEC project was to develop a user-friendly software package that will allow the identification of areas vulnerable or resilient to radiocesium deposition in the Central European countries: Poland, Hungary and the Czech Republic. The software package will incorporate a semi- mechanistic soil-to-plant transfer model which uses commonly measured soil properties to estimate the dynamic behaviour of deposited radiocesium. This model was developed for the European Commission IV th Framework programme Spatial Analysis of Vulnerable Ecosystems (SAVE) project. In the SAVEC software package, spatially variable data (including 137 CS deposition, soil property , agricultural production and dietary data) can be used to assess the consequences of the deposition in the three Central European countries following nuclear accidents. The SAVEC project collates data of sufficient resolution specific to Poland, Hungary and the Czech Republic for integration within the SAVE-IT software package to allow the identification of areas and population groups that may be vulnerable to radiocesium deposition. From this viewpoint the samples of soil and vegetation were collected (1999 and 2000; the locations of the sampling places are in Fig. 1.) in which the content of 137 CS by semiconductor gamma spectrometry were determined. The mass activity of 137 CS were used for calculation of soil-to-plant transfer factors. (authors)

  20. Effect of polyacrylamide on soil physical and hydraulic properties

    Science.gov (United States)

    Albalasmeh, Ammar; Gharaibeh, Mamoun; Hamdan, Enas

    2017-04-01

    The effect of polyacrylamide (PAM), as a soil conditioner, on selected soil physical and hydraulic properties (infiltration rate (f(t)), hydraulic conductivity (HC), soil moisture content, aggregate stability (AS), and soil aggregation) was studied. Two types of anionic PAM were used: Low molecular weight (LPAM) (1×105 g/mol) with medium charge density (33-43) and high molecular weight (HPAM) (1-6×106 g/mol) with medium charge density (33-43). Sandy loam soil was packed into plastic columns; PAM solutions at different concentrations (100, 250, 500, and 1000 mg L-1) were used every two weeks in four wetting and drying cycles. The highest infiltration rate value was 0.16 mm s-1 at 1000 mg/L low molecular weight PAM while the highest value of infiltration rate in high PAM molecular weight was 0.11 mm s-1 compared to the control (0.01 mm s-1). Soil HC was about 3.00 cm h-1 for LPAM at 1000 mg L-1 PAM, while the highest value for HPAM was about 2 cm h-1 for the same concentration, compared to the control. The amount of water that can be held by soil increased with the addition of PAM compared to the control. Differences in water content were more pronounced in LPAM compared to HPAM. The addition of LPAM increased aggregate stability proportional to PAM concentration. Moreover, 1000 mg L-1 produced the highest aggregate stability (19{%}) compared to HPAM and control (7{%} and 5{%}), respectively. As PAM concentration increased, the geometric mean diameter (GMD) increased for both PAM molecular weights compared to control (0.4 mm). At 1000 mg L-1 the GMD values were 0.88 mm and 0.79 mm for LPAM and HPAM, respectively. The addition of PAM improved soil physical and hydraulic properties, with an advantage to LPAM owing that to its ability to penetrate soil aggregates and therefore stabilizing them.

  1. Copper bioavailability and extractability as related to chemical properties of contaminated soils from a vine-growing area

    International Nuclear Information System (INIS)

    Chaignon, V.; Sanchez-Neira, I.; Herrmann, P.; Jaillard, B.; Hinsinger, P.

    2003-01-01

    Root Cu concentration is a good indicator of soil Cu bioavailability. - Vineyard soils have been contaminated by Cu as a consequence of the long-term use of Cu salts as fungicides against mildew. This work aimed at identifying which soil parameters were the best related to Cu bioavailability, as assessed by measuring the concentrations of Cu in shoots and roots of tomato cropped (in lab conditions) over a range of 29 (24 calcareous and five acidic) Cu-contaminated topsoils from a vine-growing area (22-398 mg Cu kg -1 ). Copper concentrations in tomato shoots remained in the adequate range and were independent of soil properties and soil Cu content. Conversely, strong, positive correlations were found between root Cu concentration, total soil Cu, EDTA- or K-pyrophosphate-extractable Cu and organic C contents in the 24 calcareous soils, suggesting a prominent role of organic matter in the retention and bioavailability of Cu. Such relations were not observed when including the five acidic soils in the investigated population, suggesting a major pH effect. Root Cu concentration appeared as a much more sensitive indicator of soil Cu bioavailability than shoot Cu concentration. Simple extractions routinely used in soil testing procedures (total and EDTA-extractable Cu) were adequate indicators of Cu bioavailability for the investigated calcareous soils, but not when different soil types were considered (e.g. acidic versus calcareous soils)

  2. EFFECT OF ALTERNATIVE MULTINUTRIENT SOURCES ON SOIL CHEMICAL PROPERTIES

    Directory of Open Access Journals (Sweden)

    Vanessa Martins

    2015-02-01

    Full Text Available The current high price of potassium chloride and the dependence of Brazil on imported materials to supply the domestic demand call for studies evaluating the efficiency of alternative sources of nutrients. The aim of this work was to evaluate the effect of silicate rock powder and a manganese mining by-product, and secondary materials originated from these two materials, on soil chemical properties and on brachiaria production. This greenhouse experiment was conducted in pots with 5 kg of soil (Latossolo Vermelho-Amarelo distrófico - Oxisol. The alternative nutrient sources were: verdete, verdete treated with NH4OH, phonolite, ultramafic rock, mining waste and the proportion of 75 % of these K fertilizers and 25 % lime. Mixtures containing 25 % of lime were heated at 800 ºC for 1 h. These sources were applied at rates of 0, 150, 300, 450 and 600 kg ha-1 K2O, and incubated for 45 days. The mixtures of heated silicate rocks with lime promoted higher increases in soil pH in decreasing order: ultramafic rock>verdete>phonolite>mining waste. Applying the mining waste-lime mixture increased soil exchangeable K, and available P when ultramafic rock was incorporated. When ultramafic rock was applied, the release of Ca2+ increased significantly. Mining subproduct released the highest amount of Zn2+ and Mn2+ to the soil. The application of alternative sources of K, with variable chemical composition, altered the nutrient availability and soil chemical properties, improving mainly plant development and K plant uptake, and are important nutrient sources.

  3. Holistic information evaluation of divergence of soil's properties by using of legacy data of large scale monitoring surveys

    Science.gov (United States)

    Mikheeva, Irina

    2017-04-01

    Identification of tendencies of soil's transformations is very important for adequate ecological and economical assessment of degradation of soils. But monitoring of conditions of soils, and other natural objects, bring up a number of important methodological questions, including the probabilistic and statistical analysis of the accumulated legacy data and their use for verification of quantitative estimates of natural processes. Owing to considerable natural variability there is a problem of a reliable assessment of contemporary soil evolution under the influence of environmental management and climate changes. When studying dynamics of soil quality it is necessary to consider soil as open complex system with parameters which significantly vary in space. The analysis of probabilistic distributions of attributes of studied system is informative for the characteristic of holistic state and behavior of the system. Therefore earlier we had offered the method of evaluation of alterations of soils by analysis of changes of pdf of their properties and their statistical entropy. The executed analysis of dynamics of pdf showed that often opposite tendencies to decrease and to increase of property can be shown at the same time. However to give an adequate quantitative evaluation of changes of soil properties it is necessary to characterize them in general. We proposed that it is reasonable to name processes of modern changes in soil properties concerning their start meaning by the term "divergence" and investigate it quantitatively. For this purpose we suggested to use value of information divergence which is defined as a measure of distinctions of pdf in compared objects or in various time. As the measure of dissimilarity, divergence should satisfy come conditions, the most important is scale-invariance property. Information divergence was used by us for evaluation of distinctions of soils according heterogeneity of factors of soil formation and with course of natural and

  4. Some aspects of time domain reflectometry, neutron scattering, and capacitance methods for soil water content measurement

    International Nuclear Information System (INIS)

    Evett, S.R.

    2000-01-01

    Soil-water measurements encounter particular problems related to the physics of the method used. For time domain reflectometry (TDR), these relate to wave form shape changes caused by soil, soil water, and TDR probe properties. Methods of wave form interpretation that overcome these problems are discussed and specific computer algorithms are presented. Neutron scattering is well understood, but calibration methods remain critical to accuracy and precision, and are discussed with recommendations for field calibration and use. Capacitance probes tend to exhibit very small radii of influence, thus are sensitive to small-scale changes in soil properties, and are difficult or impossible to field calibrate. Field comparisons of neutron and capacitance probes are presented. (author)

  5. Vegetation-induced spatial variability of soil redox properties in wetlands

    Science.gov (United States)

    Szalai, Zoltán; Jakab, Gergely; Kiss, Klaudia; Ringer, Marianna; Balázs, Réka; Zacháry, Dóra; Horváth Szabó, Kata; Perényi, Katalin

    2016-04-01

    Vegetation induced land patches may result spatial pattern of on soil Eh and pH. These spatial pattern are mainly emerged by differences of aeration and exudation of assimilates. Present paper focuses on vertical extent and temporal dynamics of these patterns in wetlands. Two study sites were selected: 1. a plain wetland on calcareous sandy parent material (Ceglédbercel, Danube-Tisza Interfluve, Hungary); 2. headwater wetland with calcareous loamy parent material (Bátaapáti, Hungary). Two vegetation patches were studied in site 1: sedgy (dominated by Carex riparia) and reedy (dominated by Phragmites australis). Three patches were studied in site2: sedgy1 (dominated by C vulpina), sedgy 2 (C. riparia); nettle-horsetail (Urtica dioica and Equisetum arvense). Boundaries between patches were studied separately. Soil redox, pH and temperature studied by automated remote controlled instruments. Three digital sensors (Ponsell) were installed in each locations: 20cm and 40cm sensors represent the solum and 100 cm sensor monitors the subsoil). Groundwater wells were installed near to triplets for soil water sampling. Soil Eh, pH and temperature values were recorded in each 10 minutes. Soil water sampling for iron and DOC were carried out during saturated periods. Spatial pattern of soil Eh is clearly caused by vegetation. We measured significant differences between Eh values of the studied patches in the solum. We did not find this kinds horizontal differences in the subsoil. Boundaries of the patches usually had more reductive soil environment than the core areas. We have found temporal dynamics of the spatial redox pattern. Differences were not so well expressed during wintertime. These spatial patterns had influence on the DOC and iron content of porewater, as well. Highest temporal dynamics of soil redox properties and porewater iron could be found in the boundaries. These observations refer to importance patchiness of vegetation on soil chemical properties in

  6. Survey and Zoning of Soil Physical and Chemical Properties Using Geostatistical Methods in GIS (Case Study: Miankangi Region in Sistan

    Directory of Open Access Journals (Sweden)

    M. Hashemi

    2017-02-01

    Full Text Available Introduction: In order to provide a database, it is essential having access to accurate information on soil spatial variation for soil sustainable management such as proper application of fertilizers. Spatial variations in soil properties are common but it is important for understanding these changes, particularly in agricultural lands for careful planning and land management. Materials and Methods: To this end, in winter 1391, 189 undisturbed soil samples (0-30 cm depth in a regular lattice with a spacing of 500 m were gathered from the surface of Miankangi land, Sistan plain, and their physical and chemical properties were studied. The land area of the region is about 4,500 hectares; the average elevation of studied area is 489.2 meters above sea level with different land uses. Soil texture was measured by the hydrometer methods (11, Also EC and pH (39, calcium carbonate equivalent (37 and the saturation percentage of soils were determined. Kriging, Co-Kriging, Inverse Distance Weighting and Local Polynomial Interpolation techniques were evaluated to produce a soil characteristics map of the study area zoning and to select the best geostatistical methods. Cross-validation techniques and Root Mean Square Error (RMSE were used. Results and Discussion: Normalized test results showed that all of the soil properties except calcium carbonate and soil clay content had normal distribution. In addition, the results of correlation test showed that the soil saturation percentage was positively correlated with silt content (r=0.43 and p

  7. Variability of Measured Runoff and Soil Loss from Field Plots

    Directory of Open Access Journals (Sweden)

    F. Asadzadeh

    2016-02-01

    Full Text Available Introduction: Field plots are widely used in studies related to the measurements of soil loss and modeling of erosion processes. Research efforts are needed to investigate factors affecting the data quality of plots. Spatial scale or size of plots is one of these factors which directly affects measuring runoff and soil loss by means of field plots. The effect of plot size on measured runoff or soil loss from natural plots is known as plot scale effect. On the other hand, variability of runoff and sediment yield from replicated filed plots is a main source of uncertainty in measurement of erosion from plots which should be considered in plot data interpretation processes. Therefore, there is a demand for knowledge of soil erosion processes occurring in plots of different sizes and of factors that determine natural variability, as a basis for obtaining soil loss data of good quality. This study was carried out to investigate the combined effects of these two factors by measurement of runoff and soil loss from replicated plots with different sizes. Materials and Methods: In order to evaluate the variability of runoff and soil loss data seven plots, differing in width and length, were constructed in a uniform slope of 9% at three replicates at Koohin Research Station in Qazvin province. The plots were ploughed up to down slope in September 2011. Each plot was isolated using soil beds with a height of 30 cm, to direct generated surface runoff to the lower part of the plots. Runoff collecting systems composed of gutters, pipes and tankswere installed at the end of each plot. During the two-year study period of 2011-2012, plots were maintained in bare conditions and runoff and soil loss were measured for each single event. Precipitation amounts and characteristics were directly measured by an automatic recording tipping-bucket rain gauge located about 200 m from the experimental plots. The entire runoff volume including eroded sediment was measured on

  8. Influence of soil properties and soil leaching on the toxicity of ionic silver to plants.

    Science.gov (United States)

    Langdon, Kate A; McLaughlin, Mike J; Kirby, Jason K; Merrington, Graham

    2015-11-01

    Silver (Ag) has been shown to exhibit antimicrobial properties; as a result, it is being used increasingly in a wide range of consumer products. With these uses, the likelihood that Ag may enter the environment has increased, predominately via land application of biosolids or irrigation with treated wastewater effluent. The aim of the present study was to investigate the toxicity of Ag to 2 plant species: barley (Hordeum vulgare L. CV Triumph) and tomato (Lycopersicum esculentum) in a range of soils under both leached and unleached conditions. The concentrations that resulted in a 50% reduction of plant growth (EC50) were found to vary up to 20-fold across the soils, indicating a large influence of soil type on Ag toxicity. Overall, barley root elongation was found to be the least sensitive to added Ag, with EC50 values ranging from 51 mg/kg to 1030 mg/kg, whereas the tomato plant height showed higher sensitivity with EC50 values ranging from 46 mg/kg to 486 mg/kg. The effect of leaching was more evident in the barley toxicity results, where higher concentrations of Ag were required to induce toxicity. Variations in soil organic carbon and pH were found to be primarily responsible for mitigating Ag toxicity; therefore, these properties may be used in future risk assessments for Ag to predict toxicity in a wide range of soil types. © 2015 SETAC.

  9. Soil physical properties regulate lethal heating during burning of woody residues

    Science.gov (United States)

    Matt Busse; Carol Shestak; Ken Hubbert; Eric Knapp

    2010-01-01

    Temperatures well in excess of the lethal threshold for roots (60°C) have been measured in forest soils when woody fuels are burned. Whether this heat pulse is strongly moderated by soil moisture or soil texture is not fully understood, however. We measured soil heat profi les during 60 experimental burns, identifying changes in maximum soil temperature and heat...

  10. The physical properties and compaction characteristics of swelling soils

    International Nuclear Information System (INIS)

    Komine, Hideo; Ogata, Nobuhide

    1990-01-01

    Expansive soils have recently attracted increasing attention as the back filling material for the repositories of high level nuclear wastes or as the material for improving extremely soft grounds. However, since very little has been known concerning the physical and mechanical properties of such materials, it is necessary to clarify the swelling, compaction and thermal characteristics of expansive soils. For this purpose, various kinds of index tests and a series of static compaction tests were performed using several kinds of swelling soils in order to investigate the relationship between the fundamental physical properties and the compaction characteristics. Since the ordinary testing method stipulated in JIS is difficult to perform for such expansive soils, the new method was proposed to obtained the reliable values of specific gravity, grain size distribution and liquid/plastic limits. By this method, some representative values were presented for various kinds of clay including bentonite. As the results of static compaction tests, the compaction characteristics of clay were strongly dependent on the plastic limit of clay. The maximum dry density and optimum water content were strongly dependent on both plastic limit and compaction pressure. (K.I.)

  11. Lodgepole pine site index in relation to synoptic measures of climate, soil moisture and soil nutrients.

    Science.gov (United States)

    G. Geoff Wang; Shongming Huang; Robert A. Monserud; Ryan J. Klos

    2004-01-01

    Lodgepole pine site index was examined in relation to synoptic measures of topography, soil moisture, and soil nutrients in Alberta. Data came from 214 lodgepole pine-dominated stands sampled as a part of the provincial permanent sample plot program. Spatial location (elevation, latitude, and longitude) and natural subregions (NSRs) were topographic variables that...

  12. Organic farming and cover crops as an alternative to mineral fertilizers to improve soil physical properties

    Science.gov (United States)

    Sánchez de Cima, Diego; Luik, Anne; Reintam, Endla

    2015-10-01

    For testing how cover crops and different fertilization managements affect the soil physical properties in a plough based tillage system, a five-year crop rotation experiment (field pea, white potato, common barley undersown with red clover, red clover, and winter wheat) was set. The rotation was managed under four different farming systems: two conventional: with and without mineral fertilizers and two organic, both with winter cover crops (later ploughed and used as green manure) and one where cattle manure was added yearly. The measurements conducted were penetration resistance, soil water content, porosity, water permeability, and organic carbon. Yearly variations were linked to the number of tillage operations, and a cumulative effect of soil organic carbon in the soil as a result of the different fertilization amendments, organic or mineral. All the systems showed similar tendencies along the three years of study and differences were only found between the control and the other systems. Mineral fertilizers enhanced the overall physical soil conditions due to the higher yield in the system. In the organic systems, cover crops and cattle manure did not have a significant effect on soil physical properties in comparison with the conventional ones, which were kept bare during the winter period. The extra organic matter boosted the positive effect of crop rotation, but the higher number of tillage operations in both organic systems counteracted this effect to a greater or lesser extent.

  13. Effect of biochar on reclaimed tidal land soil properties and maize (Zea mays L.) response.

    Science.gov (United States)

    Kim, Hyuck-Soo; Kim, Kwon-Rae; Yang, Jae E; Ok, Yong Sik; Owens, Gary; Nehls, Thomas; Wessolek, Gerd; Kim, Kye-Hoon

    2016-01-01

    Reclaimed tidal land soil (RTLS) often contains high levels of soluble salts and exchangeable Na that can adversely affect plant growth. The current study examined the effect of biochar on the physicochemical properties of RTLS and subsequently the influence on plant growth performance. Rice hull derived biochar (BC) was applied to RTLS at three different rates (1%, 2%, and 5% (w/w)) and maize (Zea mays L.) subsequently cultivated for 6weeks. While maize was cultivated, 0.1% NaCl solution was supplied from the bottom of the pots to simulate the natural RTLS conditions. Biochar induced changes in soil properties were evaluated by the water stable aggregate (WSA) percentage, exchangeable sodium percentage (ESP), soil organic carbon contents, cation exchange capacity, and exchangeable cations. Plant response was measured by growth rate, nutrient contents, and antioxidant enzyme activity of ascorbate peroxidase (APX) and glutathione reductase (GR). Application of rice hull derived biochar increased the soil organic carbon content and the percentage of WSA by 36-69%, while decreasing the ESP. The highest dry weight maize yield was observed from soil which received 5% BC (w/w), which was attributed to increased stability of water-stable aggregates and elevated levels of phosphate in BC incorporated soils. Moreover, increased potassium, sourced from the BC, induced mitigation of Na uptake by maize and consequently, reduced the impact of salt stress as evidenced by overall declines in the antioxidant activities of APX and GR. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Zinc availability in relation to selected soil properties in a crude oil polluted eutric tropofluvent

    International Nuclear Information System (INIS)

    Chukwuma, M.C.; Eshett, E.T.; Onweremadu, E.U.; Okon, M.A.

    2010-01-01

    This study examined zinc availability in crude oil-polluted soils. The aim of the study was to determine the effect of zinc on the physiochemical properties of soils in relation to remediation activities. The study was located at a site in Nigeria where crude oil spillage had occurred over a period of 2 months. The region was characterized by quarternary, alluvium, meander belt, wooded back swamps as well as fresh water swamps and Sombreiro-Warri Deltaic plains with large deposits of petroleum and natural gas. Three different land units were studied, notably (1) unpolluted, (2) polluted without vegetation and (3) polluted with vegetation. Soil sampling was conducted using a transect method. Hydrometer analyses were conducted to determine particle size distribution, while a core method was used to determine bulk density. Soil pH, total carbon, phosphorus, and total nitrogen were also measured. An analysis of variance (ANOVA) was used to correlate and regress zinc availability against the selected soil properties. The study showed that zinc availability increased with increases in the value of the effective carbon cation exchange capacity in the unpolluted and polluted samples without vegetation. Zinc decreased with increased clay and organic matter content. Results suggested that soils must be reclaimed quickly in order to prevent additional degradation. 48 refs., 5 tabs., 4 figs.

  15. Zinc availability in relation to selected soil properties in a crude oil polluted eutric tropofluvent

    Energy Technology Data Exchange (ETDEWEB)

    Chukwuma, M.C.; Eshett, E.T.; Onweremadu, E.U.; Okon, M.A. [Federal Univ. of Technology, Owerri (Nigeria). Dept. of Soil Science and Technology

    2010-04-01

    This study examined zinc availability in crude oil-polluted soils. The aim of the study was to determine the effect of zinc on the physiochemical properties of soils in relation to remediation activities. The study was located at a site in Nigeria where crude oil spillage had occurred over a period of 2 months. The region was characterized by quarternary, alluvium, meander belt, wooded back swamps as well as fresh water swamps and Sombreiro-Warri Deltaic plains with large deposits of petroleum and natural gas. Three different land units were studied, notably (1) unpolluted, (2) polluted without vegetation and (3) polluted with vegetation. Soil sampling was conducted using a transect method. Hydrometer analyses were conducted to determine particle size distribution, while a core method was used to determine bulk density. Soil pH, total carbon, phosphorus, and total nitrogen were also measured. An analysis of variance (ANOVA) was used to correlate and regress zinc availability against the selected soil properties. The study showed that zinc availability increased with increases in the value of the effective carbon cation exchange capacity in the unpolluted and polluted samples without vegetation. Zinc decreased with increased clay and organic matter content. Results suggested that soils must be reclaimed quickly in order to prevent additional degradation. 48 refs., 5 tabs., 4 figs.

  16. The effect of soil properties on the toxicity of silver to the soil nitrification process.

    Science.gov (United States)

    Langdon, Kate A; McLaughlin, Mike J; Kirby, Jason K; Merrington, Graham

    2014-05-01

    Silver (Ag) is being increasingly used in a range of consumer products, predominantly as an antimicrobial agent, leading to a higher likelihood of its release into the environment. The present study investigated the toxicity of Ag to the nitrification process in European and Australian soils in both leached and unleached conditions. Overall, leaching of soils was found to have a minimal effect on the final toxicity data, with an average leaching factor of approximately 1. Across the soils, the toxicity was found to vary by several orders of magnitude, with concentrations of Ag causing a 50% reduction in nitrification relative to the controls (EC50) ranging from 0.43 mg Ag/kg to >640 mg Ag/kg. Interestingly, the dose-response relationships in most of the soils showed significant stimulation in nitrification at low Ag concentrations (i.e., hormesis), which in some cases produced responses up to double that observed in the controls. Soil pH and organic carbon were the properties found to have the greatest influence on the variations in toxicity thresholds across the soils, and significant relationships were developed that accounted for approximately 90% of the variability in the data. The toxicity relationships developed from the present study will assist in future assessment of potential Ag risks and enable the site-specific prediction of Ag toxicity. © 2014 SETAC.

  17. Weed Mapping with Co-Kriging Using Soil Properties

    DEFF Research Database (Denmark)

    Heisel, Torben; Ersbøll, Annette Kjær; Andreasen, Christian

    1999-01-01

    Our aim is to build reliable weed maps to control weeds in patches. Weed sampling is time consuming but there are some shortcuts. If an intensively sampled variable (e.g. soil property) can be used to improve estimation of a sparsely sampled variable (e.g. weed distribution), one can reduce weed...... sampling. The geostatistical estimation method co-kriging uses two or more sampled variables, which are correlated, to improve the estimation of one of the variables at locations where it was not sampled. We did an experiment on a 2.1 ha winter wheat field to compare co-kriging using soil properties......, with kriging based only on one variable. The results showed that co-kriging Lamium spp. from 96 0.25m2 sample plots ha-1 with silt content improved the prediction variance by 11% compared to kriging. With 51 or 18 sample plots ha-1 the prediction variance was improved by 21 and 15%....

  18. PHYSICAL AND CHEMICAL PROPERTIES IN RELATION WITH SOIL PERMEABILITY IN THE AREA OF VELIKA GORICA WELL FIELD

    Directory of Open Access Journals (Sweden)

    Zoran Kovač

    2018-01-01

    Full Text Available Hydraulic parameters affects behaviour of various ions in soils. The goal of this paper was to get better understanding of relationship between physical and chemical properties and soil permeability at the location of case study profile Velika Gorica, based on the physical and chemical data. Soil profile is situated in the Eutric Cambisol of the Zagreb aquifer, Croatia. Zagreb aquifer represents the only source of potable water for inhabitants of the City of Zagreb and Zagreb County. Based on the data obtained from particle size analysis, soil hydraulic parameters and measured water content, unsaturated hydraulic conductivity values were calculated for the estimation of soil profile permeability. Soil water retention curves and unsaturated hydraulic conductivities are very similar for all depths because soil content does not change significantly through the depth. Determination of anions and cations on soil samples was performed using the method of ion chromatography. Results showed decrease of ions concentrations after 0.6 m depth. SAR distribution in the soil profile shows that SAR values are not significantly changing at the soil profile. The highest CEC and EC values are determined in horizon Bw developed in 0.6 m depth which is consistent with highest SAR value and ions concentrations. All results suggest that physical and chemical properties of investigated profile are in relationship with soil permeability.

  19. Mulching as a strategy to improve soil properties and reduce soil erodibility in coffee farming systems of Rwanda

    NARCIS (Netherlands)

    Nzeyimana, I.; Hartemink, A.E.; Ritsema, C.J.; Stroosnijder, L.; Huerta Lwanga, Esperanza; Geissen, V.

    2017-01-01

    In Rwanda, mulch is applied in coffee fields to control soil erosion. The objective of this paper is to quantify the effects of different types of mulch on soil properties and soil erodibility in coffee farming systems in three different agro-ecological zones of the highlands of Rwanda. The

  20. Compared performance of penetrometers and effect of soil water content on penetration resistance measurements

    Directory of Open Access Journals (Sweden)

    Edison Aparecido Mome Filho

    2014-06-01

    Full Text Available Modern agriculture techniques have a great impact on crops and soil quality, especially by the increased machinery traffic and weight. Several devices have been developed for determining soil properties in the field, aimed at managing compacted areas. Penetrometry is a widely used technique; however, there are several types of penetrometers, which have different action modes that can affect the soil resistance measurement. The objective of this study was to compare the functionality of two penetrometry methods (manual and automated mode in the field identification of compacted, highly mechanized sugarcane areas, considering the influence of soil water volumetric content (θ on soil penetration resistance (PR. Three sugarcane fields on a Rhodic Eutrudrox were chosen, under a sequence of harvest systems: one manual harvest (1ManH, one mechanized harvest (1MH and three mechanized harvests (3MH. The different degrees of mechanization were associated to cumulative compaction processes. An electronic penetrometer was used on PR measurements, so that the rod was introduced into the soil by hand (Manual and by an electromechanical motor (Auto. The θ was measured in the field with a soil moisture sensor. Results showed an effect of θ on PR measurements and that regression models must be used to correct data before comparing harvesting systems. The rod introduction modes resulted in different mean PR values, where the "Manual" overestimated PR compared to the "Auto" mode at low θ.

  1. How do soil properties and soil carbon stocks change after land abandonment in Mediterranean mountain areas?

    Science.gov (United States)

    Nadal Romero, Estela; Cammeraat, Erik; Pérez Cardiel, Estela; Lasanta, Teodoro

    2016-04-01

    Land abandonment and subsequent revegetation processes (due to secondary succession and afforestation practices) are global issues with important implications in Mediterranean mountain areas. Moreover, the effects of land use changes on soil carbon stocks are a matter of concern stated in international policy agendas on the mitigation of greenhouse emissions, and afforestation practices are increasingly viewed as an environmental restorative land use change prescription and are considered one of the most efficient carbon sequestration strategies currently available. The MED-AFFOREST project aims to gain more insight into the discussion by exploring the following central research questions: (i) what is the impact of land abandonment on soil properties? and (ii) how do soil organic carbon change after land abandonment? The main objective of this study is to assess the effects of land abandonment, land use change and afforestation practices on soil properties and soil organic carbon (SOC) dynamics. For this aim, five different land covers (bare soil, meadows, secondary succession, Pinus sylvestris (PS) and Pinus nigra (PN) afforestation), in the Central Spanish Pyrenees were analysed. Results showed that changes in soil properties after land abandonment were limited, even if afforestation practices were carried out and no differences were observed between natural succession and afforestation. The results on SOC dynamics showed that: (i) SOC contents were higher in the PN sites in the topsoil (10 cm), (ii) when all the profile was considered no significant differences were observed between meadows and PN, (iii) SOC accumulation under secondary succession is a slow process, and (iv) meadows should also be considered due to the relative importance in SOC stocks. The first step of SOC stabilization after afforestation is the formation of macro-aggregates promoted by large inputs of SOC, with a high contribution of labile organic matter. However, our respiration

  2. Measurement of the vertical infiltration parameters and water redistribution in LRd and LEa soils by gamma-ray transmission technique

    International Nuclear Information System (INIS)

    Souza, A.D.B. de; Saito, H.; Appoloni, C.R.; Coimbra, M.M.; Parreira, P.S.

    1991-01-01

    The properties of soil water diffusivity and soil hydraulic conductivity of two horizons (0-20 cm and 20-40 cm) from Latossolo Roxo distrofico (LRd) and Latossolo Vermelho escuro (LEa) soil samples, have been measured in laboratory through the vertical infiltration and redistribution of water in soil columns. The moisture profile as a function of time for each position in the soil column were obtained with the gamma-ray transmission technique, using a sup(241)Am gamma-ray source, a Na (I) T1 scintillation detector and gamma spectrometry standard electronic. (author)

  3. The behaviour of EDDHA isomers in soils as influenced by soil properties.

    OpenAIRE

    Schenkeveld, W.D.C.; Reichwein, A.M.; Temminghoff, E.J.M.; Riemsdijk, van, W.H.

    2007-01-01

    FeEDDHA products are applied to correct iron chlorosis in plants and consist of a mixture of EDDHA isomers chelated to iron. In this study such mixtures have been divided into four (groups of) isomers: racemic o,o-EDDHA, meso o,o-EDDHA, o,p-EDDHA and rest-EDDHA. The physical and chemical properties of these isomers differ and hence does their ability to deliver Fe to plants. To come to a soil-specific iron fertilization recommendation, the behaviour of the EDDHA isomers in the soil needs to b...

  4. Early Response of Soil Properties and Function to Riparian Rainforest Restoration

    Science.gov (United States)

    Gageler, Rose; Bonner, Mark; Kirchhof, Gunnar; Amos, Mark; Robinson, Nicole; Schmidt, Susanne; Shoo, Luke P.

    2014-01-01

    Reforestation of riparian zones is increasingly practiced in many regions for purposes of biodiversity conservation, bank stabilisation, and improvement in water quality. This is in spite of the actual benefits of reforestation for recovering underlying soil properties and function remaining poorly understood. Here we compare remnant riparian rainforest, pasture and reforestation plantings aged 2–20 years in an Australian subtropical catchment on ferrosols to determine the extent to which reforestation restores key soil properties. Of the nine soil attributes measured (total nitrogen, nitrate and ammonium concentrations, net nitrification and ammonification rates, organic carbon, bulk density, fine root biomass and water infiltration rates), only infiltration rates were significantly lower in pasture than remnant riparian rainforest. Within reforestation plantings, bulk density decreased up to 1.4-fold and infiltration rates increased up to 60-fold with time post-reforestation. Our results suggest that the main outcome of belowground processes of early reforestation is the recovery of the soils' physical structure, with potential beneficial ecosystem services including reduced runoff, erosion and associated sediment and nutrient loads in waterways. We also demonstrate differential impacts of two commonly planted tree species on a subset of soil properties suggesting that preferential planting of select species could accelerate progress on specific restoration objectives. PMID:25117589

  5. Early response of soil properties and function to riparian rainforest restoration.

    Directory of Open Access Journals (Sweden)

    Rose Gageler

    Full Text Available Reforestation of riparian zones is increasingly practiced in many regions for purposes of biodiversity conservation, bank stabilisation, and improvement in water quality. This is in spite of the actual benefits of reforestation for recovering underlying soil properties and function remaining poorly understood. Here we compare remnant riparian rainforest, pasture and reforestation plantings aged 2-20 years in an Australian subtropical catchment on ferrosols to determine the extent to which reforestation restores key soil properties. Of the nine soil attributes measured (total nitrogen, nitrate and ammonium concentrations, net nitrification and ammonification rates, organic carbon, bulk density, fine root biomass and water infiltration rates, only infiltration rates were significantly lower in pasture than remnant riparian rainforest. Within reforestation plantings, bulk density decreased up to 1.4-fold and infiltration rates increased up to 60-fold with time post-reforestation. Our results suggest that the main outcome of belowground processes of early reforestation is the recovery of the soils' physical structure, with potential beneficial ecosystem services including reduced runoff, erosion and associated sediment and nutrient loads in waterways. We also demonstrate differential impacts of two commonly planted tree species on a subset of soil properties suggesting that preferential planting of select species could accelerate progress on specific restoration objectives.

  6. Leaching Properties of Naturally Occurring Heavy Metals from Soils

    Science.gov (United States)

    Zhang, M.; Hoshino, M.; Yoshikawa, M.; Hara, J.; Sugita, H.

    2014-12-01

    The major threats to human health from heavy metals are associated with exposure to arsenic, lead, cadmium, chromium, mercury, as well as some other elements. The effects of such heavy metals on human health have been extensively studied and reviewed by international organizations such as WHO. Due to their toxicity, heavy metal contaminations have been regulated by national environmental standards in many countries, and/or laws such as the Soil Contamination Countermeasures Act in Japan. Leaching of naturally occurring heavy metals from the soils, especially those around abandoned metal mines into surrounding water systems, either groundwater or surface water systems, is one of the major pathways of exposure. Therefore, understanding the leaching properties of toxic heavy metals from naturally polluted soils is of fundamentally importance for effectively managing abandoned metal mines, excavated rocks discharged from infrastructure constructions such as tunneling, and/or selecting a pertinent countermeasure against pollution when it is necessary. In this study, soil samples taken from the surroundings of abandoned metal mines in different regions in Japan were collected and analyzed. The samples contained multiple heavy metals such as lead, arsenic and chromium. Standard leaching test and sequential leaching test considering different forms of contaminants, such as trivalent and pentavalent arsenics, and trivalent and hexavalent chromiums, together with standard test for evaluating total concentration, X-ray Fluorescence Analysis (XRF), X-ray diffraction analysis (XRD) and Cation Exchange Capacity (CEC) tests were performed. In addition, sequential leaching tests were performed to evaluate long-term leaching properties of lead from representative samples. This presentation introduces the details of the above experimental study, discusses the relationships among leaching properties and chemical and mineral compositions, indicates the difficulties associated with

  7. Response of soil physicochemical properties and enzyme activities to long-term reclamation of coastal saline soil, Eastern China.

    Science.gov (United States)

    Xie, Xuefeng; Pu, Lijie; Wang, Qiqi; Zhu, Ming; Xu, Yan; Zhang, Meng

    2017-12-31

    Soil enzyme activity during different years of reclamation and land use patterns could indicate changes in soil quality. The objective of this research is to explore the dynamics of 5 soil enzyme activities (dehydrogenase, amylase, urease, acid phosphatase and alkaline phosphatase) involved in C, N, and P cycling and their responses to changes in soil physicochemical properties resulting from long-term reclamation of coastal saline soil. Soil samples from a total of 55 sites were collected from a coastal reclamation area with different years of reclamation (0, 7, 32, 40, 63a) in this study. The results showed that both long-term reclamation and land use patterns have significant effects on soil physicochemical properties and enzyme activities. Compared with the bare flat, soil water content, soil bulk density, pH and electrical conductivity showed a decreasing trend after reclamation, whereas soil organic carbon, total nitrogen and total phosphorus tended to increase. Dehydrogenase, amylase and acid phosphatase activities initially increased and then decreased with increasing years of reclamation, whereas urease and alkaline phosphatase activities were characterized by an increase-decrease-increase trend. Moreover, urease, acid phosphatase and alkaline phosphatase activities exhibited significant differences between coastal saline soil with 63years of reclamation and bare flat, whereas dehydrogenase and amylase activities remained unchanged. Aquaculture ponds showed higher soil water content, pH and EC but lower soil organic carbon, total nitrogen and total phosphorus than rapeseed, broad bean and wheat fields. Rapeseed, broad bean and wheat fields displayed higher urease and alkaline phosphatase activities and lower dehydrogenase, amylase and acid phosphatase activities compared with aquaculture ponds. Redundancy analysis revealed that the soil physicochemical properties explained 74.5% of the variation in soil enzyme activities and that an obvious relationship

  8. Effect of soil type and soil management on soil physical, chemical and biological properties in commercial organic olive orchards in Southern Spain

    Science.gov (United States)

    Gomez, Jose Alfonso; Auxiliadora Soriano, Maria; Montes-Borrego, Miguel; Navas, Juan Antonio; Landa, Blanca B.

    2014-05-01

    One of the objectives of organic agriculture is to maintain and improve soil quality, while simultaneously producing an adequate yield. A key element in organic olive production is soil management, which properly implemented can optimize the use of rainfall water enhancing infiltration rates and controlling competition for soil water by weeds. There are different soil management strategies: eg. weed mowing (M), green manure with surface tillage in spring (T), or combination with animal grazing among the trees (G). That variability in soil management combined with the large variability in soil types on which organic olive trees are grown in Southern Spain, difficult the evaluation of the impact of different soil management on soil properties, and yield as well as its interpretation in terms of improvement of soil quality. This communications presents the results and analysis of soil physical, chemical and biological properties on 58 soils in Southern Spain during 2005 and 2006, and analyzed and evaluated in different studies since them. Those 58 soils were sampled in 46 certified commercial organic olive orchards with four soil types as well as 12 undisturbed areas with natural vegetation near the olive orchards. The four soil types considered were Eutric Regosol (RGeu, n= 16), Eutric Cambisol (CMeu, n=16), Calcaric Regosol (RGca, n=13 soils sampled) and Calcic Cambisol (CMcc), and the soil management systems (SMS) include were 10 light tillage (LT), 16 sheep grazing (G), 10 tillage (T), 10 mechanical mowing (M), and 12 undisturbed areas covered by natural vegetation (NV-C and NV-S). Our results indicate that soil management had a significant effect on olive yield as well as on key soil properties. Among these soil properties are physical ones, such as infiltration rate or bulk density, chemical ones, especially organic carbon concentration, and biological ones such as soil microbial respiration and bacterial community composition. Superimpose to that soil

  9. Prediction of cesium-134 and strontium-85 crop uptake based on soil properties

    International Nuclear Information System (INIS)

    Roca, M.C.; Vallejo, V.R.; Roig, M.; Tent, J.; Vidal, M.; Rauret, G.

    1997-01-01

    Nowadays, there is still the need to improve the quantification of parameters that affect radionuclide mobility. With this aim, radiocesium and radiostrontium soil-to-plant transfer was measured in lysimeters in a Calcic Luvisol, loamy soil and in a Fluvisol, loam-sandy soil, using lettuce [Lactuca sativa L. cv. Kinemontepas] and pea plants [Pisum sativum L. cv. Kelvedon Wonder]. Weighted Concentration Ratios (WCR), expressed as kg soil/kg plant, were calculated for different growth stages. Weighted Concentration Ratios were in general higher for 85Sr than for 134Cs, and also higher in the loam-sandy than in the loamy soil. To predict plant uptake, we evaluated a set of soil properties to define a prediction factor for the relative transfer in the two soils using cation exchange capacity (CEC) and radionuclide available fraction (fav) for radiostrontium, and soil solution composition, solid-liquid distribution coefficient, and radionuclide available fraction for radiocesium. The ratios of WCR in the loam-sandy and loamy soil were compared with the prediction factor. There was good agreement in lettuce for 85Sr (ratio of WCR was 5.4 for seedling and 3.9 for commercial samples, whereas prediction factor was 3.1) and for 134Cs (ratio of WCR was 5.1 for seedling and 5.5 for commercial samples, the prediction factor being 5.1), although for pea only the relative root uptake of radiocesium in seedling pea was well predicted (the ratio of WCR was 8.8, the prediction factor being 9.1). These soil parameters improved former predictions based solely on the fav, although factors depending on plant physiology should be better evaluated

  10. [Changes of soil physical properties during the conversion of cropland to agroforestry system].

    Science.gov (United States)

    Wang, Lai; Gao, Peng Xiang; Liu, Bin; Zhong, Chong Gao; Hou, Lin; Zhang, Shuo Xin

    2017-01-01

    To provide theoretical basis for modeling and managing agroforestry systems, the influence of conversion of cropland to agroforestry system on soil physical properties was investigated via a walnut (Juglans regia)-wheat (Triticum aestivum) intercropping system, a wide spreading local agroforestry model in northern Weihe River of loess area, with the walnut and wheat monoculture systems as the control. The results showed that the improvement of the intercropping system on soil physical properties mainly appeared in the 0-40 cm soil layer. The intercropping system could prevent soil bulk density rising in the surface soil (0-20 cm), and the plow pan in the 20-40 cm soil layer could be significantly alleviated. The intercropping system had conti-nuous improvement on soil field capacity in each soil layer with the planting age increase, and the soil field capacity was higher than that of each monoculture system in each soil layer (except 20-40 cm soil layer) since the 5th year after planting. The intercropping system had continuous improvement on soil porosity in each soil layer, but mainly in the 0-20 and 20-40 cm soil layer, and the ratio of capillary porosity was also improved. The soil bulk density, field capacity and soil porosity obtained continuous improvement during the conversion of cropland to agroforestry system, and the improvement on soil physical properties was stronger in shallow soil layer than in deep soil.

  11. Fingerprinting: Modelling and mapping physical top soil properties with the Mole

    Science.gov (United States)

    Loonstra, Eddie; van Egmond, Fenny

    2010-05-01

    The Mole is a passive gamma ray soil sensor system. It is designed for the mobile collection of radioactive energy stemming from soil. As the system is passive, it only measures energy that reaches the surface of soil. In general, this energy comes from upto 30 to 40 cm deep, which can be considered topsoil. The gathered energy spectra are logged every second, are processed with the method of Full Spectrum Analysis. This method uses all available spectral data and processes it with a Chi square optimalisation using a set of standard spectra into individual nuclide point data. A standard spectrum is the measured full spectrum of a specific detector derived when exposed to 1 Bq/kg of a nuclide. With this method the outcome of the surveys become quantitative.The outcome of a field survey with the Mole results in a data file containing point information of position, Total Counts and the decay products of 232Th, 238U, 40K and 137Cs. Five elements are therefor available for the modelling of soil properties. There are several ways for the modelling of soil properties with sensor derived gamma ray data. The Mole generates ratio scale output. For modelling a quantitative deterministic approach is used based on sample locations. This process is called fingerprinting. Fingerprinting is a comparison of the concentration of the radioactive trace elements and the lab results (pH, clay content, etc.) by regression analysis. This results in a mathematical formula describing the relationship between a dependent and independent property. The results of the sensor readings are interpolated into a nuclide map with GIS software. With the derived formula a soil property map is composed. The principle of fingerprinting can be applied on large geographical areas for physical soil properties such as clay, loam or sand (50 micron), grain size and organic matter. Collected sample data of previous field surveys within the same region can be used for the prediction of soil properties elsewhere

  12. Open charcoal chamber method for mass measurements of radon exhalation rate from soil surface

    International Nuclear Information System (INIS)

    Tsapalov, Andrey; Kovler, Konstantin; Miklyaev, Peter

    2016-01-01

    Radon exhalation rate from the soil surface can serve as an important criterion in the evaluation of radon hazard of the land. Recently published international standard ISO 11665-7 (2012) is based on the accumulation of radon gas in a closed container. At the same time since 1998 in Russia, as a part of engineering and environmental studies for the construction, radon flux measurements are made using an open charcoal chamber for a sampling duration of 3–5 h. This method has a well-defined metrological justification and was tested in both favorable and unfavorable conditions. The article describes the characteristics of the method, as well as the means of sampling and measurement of the activity of radon absorbed. The results of the metrological study suggest that regardless of the sampling conditions (weather, the mechanism and rate of radon transport in the soil, soil properties and conditions), uncertainty of method does not exceed 20%, while the combined standard uncertainty of radon exhalation rate measured from the soil surface does not exceed 30%. The results of the daily measurements of radon exhalation rate from the soil surface at the experimental site during one year are reported. - Highlights: • Radon exhalation rate from the soil surface area of 32 cm"2 can be measured at level of 10 mBq/(m"2s) at the uncertainty ≤30%. • The method has a metrological justification. • No need to consider climate conditions, soil properties and conditions, mechanism and rate of radon transport in the soil.

  13. Measurement properties of outcome measures for vitiligo. A systematic review.

    Science.gov (United States)

    Vrijman, Charlotte; Linthorst Homan, May W; Limpens, Jacqueline; van der Veen, Wietze; Wolkerstorfer, Albert; Terwee, Caroline B; Spuls, Phyllis I

    2012-11-01

    OBJECTIVE To summarize and critically appraise the evidence on the measurement properties of clinician-, patient-, and observer-reported outcomes, measuring any construct of interest in patients with all types of vitiligo. DATA SOURCES Electronic databases including PubMed (1948 to July 2011), OVID EMBASE (1980 to July 2011), and CINAHL (EBSCOhost) (1982 to July 2011) were searched. STUDY SELECTION Two authors independently screened all records for eligibility. For inclusion, the study population had to include patients with vitiligo, for which outcome measures were developed or evaluated on their measurement properties. The initial search retrieved 1249 records, of which 14 articles met the inclusion criteria. DATA EXTRACTION Characteristics of the included instruments, study population, and results of the measurement properties were extracted. The Consensus-Based Standards for the Selection of Health Status Measurement Instruments (COSMIN) 4-point checklist, combined with quality criteria for measurement properties, was used to calculate the overall level of evidence per measurement property of each instrument. Independent extraction and assessment was performed by 2 authors. DATA SYNTHESIS Eleven different measurement instruments were identified. Strong evidence was found for a positive internal consistency of the Dermatology Life Quality Index. For other instruments, the evidence of measurement properties was limited or unknown. CONCLUSIONS Recommendations on the use of specific outcome measures for vitiligo should be formulated with caution because current evidence is insufficient owing to a low number of studies with poor methodological quality and unclear clinical relevance. To recommend outcome measures for vitiligo, further research on measurement properties of clinical relevant outcome measures for vitiligo according to COSMIN quality criteria is needed.

  14. Atrazine distribution measured in soil and leachate following infiltration conditions.

    Science.gov (United States)

    Neurath, Susan K; Sadeghi, Ali M; Shirmohammadi, Adel; Isensee, Allan R; Torrents, Alba

    2004-01-01

    Atrazine transport through packed 10 cm soil columns representative of the 0-10 cm soil horizon was observed by measuring the atrazine recovery in the total leachate volume, and upper and lower soil layers following infiltration of 7.5 cm water using a mechanical vacuum extractor (MVE). Measured recoveries were analyzed to understand the influence of infiltration rate and delay time on atrazine transport and distribution in the column. Four time periods (0.28, 0.8, 1.8, and 5.5 h) representing very high to moderate infiltration rates (26.8, 9.4, 4.2, and 1.4 cm/h) were used. Replicate soil columns were tested immediately and following a 2-d delay after atrazine application. Results indicate atrazine recovery in leachate was independent of infiltration rate, but significantly lower for infiltration following a 2-d delay. Atrazine distribution in the 0-1 and 9-10 cm soil layers was affected by both infiltration rate and delay. These results are in contrast with previous field and laboratory studies that suggest that atrazine recovery in the leachate increases with increasing infiltration rate. It appears that the difference in atrazine recovery measured using the MVE and other leaching experiments using intact soil cores from this field site and the rain simulation equipment probably illustrates the effect of infiltrating water interacting with the atrazine present on the soil surface. This work suggests that atrazine mobilization from the soil surface is also dependent on interactions of the infiltrating water with the soil surface, in addition to the rate of infiltration through the surface soil.

  15. Soil quality changes in land degradation as indicated by soil chemical, biochemical and microbiological properties in a karst area of southwest Guizhou, China

    Science.gov (United States)

    Zhang, Pingjiu; Li, Lianqing; Pan, Genxing; Ren, Jingchen

    2006-12-01

    Not only the nutritional status and biological activity but also the soil ecological functioning or soil health has been impacted profoundly by land degradation in the karst area of southwest China where the karst ecosystems are generally considered as extremely vulnerable to land degradation under intensified land-use changes. The objectives of this study are to elucidate the changes in overall soil quality by a holistic approach of soil nutritional, biological activity, and soil health indicators in the karst area as impacted by intense cultivation and vegetation degradation. Topsoil samples were collected on selected eco-tesserae in a sequence of land degradation in a karst area of southwest Guizhou in 2004. The soil nutrient pools of organic carbon (Corg), extractable extracellular carbon (Cext), total soil nitrogen (Nt), alkali-hydrolyzable nitrogen (Nah), total phosphorus (Pt), available phosphorus (Pa) were analyzed by wet soil chemistry. The soil biological properties were studied by means of measurements of microbial biomass carbon (both by fumigation-extraction, FE-Cmic, and by calculation from substrate-incubation respiration, SIR-Cmic) of respiration [respiration without addition of substrates, basal respiration (BR), and potential respiration (PR) with substrate-incubation] and of soil enzyme activities (invertase, urease, and alkaline phosphatase). Soil health status was assessed by simple indices of Cmic/Corg and BR/Cmic in conjunction with bacterial community structures determined by polymerase chain reaction and denaturing gradient gel electrophoresis. While the nutritional pool parameters, such as Corg and Cext, described basically the changes in soil life-supporting capacity with cultivation interference and vegetation declined, those parameters of biological activity such as FE-Cmic, SIR, and SIR-Cmic as well as bacterial community structures measured by molecular method evidenced well the changes in soil functioning for ecosystem health with

  16. Magnetic Measurements of Atmospheric Dust Deposition in Soils

    Science.gov (United States)

    Kapička, Aleš; Petrovský, Eduard; Grison, Hana; Podrázský, Vilém; Křížek, Pavel

    2010-05-01

    Atmospheric dust of anthropogenic origin contains significant portion of minerals characterized by ferrimagnetic properties [1,2]. These minerals, mostly iron oxides, can serve as tracers of industrial pollutants in soil layers. Moreover, recent results, e.g., [3,4] show significant correlation between concentration-dependent magnetic parameters (e.g., low-field magnetic susceptibility) and concentration of heavy metals (e.g., Pb, Zn, Cd). In our paper we have investigated magnetic properties of depth soil profiles from Krušné hory Mountains (Czech Republic), which belong to a highly contaminated, so-called Black Triangle in central Europe. Emissions are determined by considerable concentration of big sources of pollution (power plants burning fossil fuel, metallurgical and chemical industry). Increased values of magnetic susceptibility (25 - 200 × 10-5 SI) were clearly identified in the top-soil layers. Thermomagnetic analyses and SEM observation indicate that the accumulated anthropogenic ferrimagnetics dominate these layers. Magnetic enhancement is limited to depths of 4-7 cm below the soil surface, usually in F-H or top of Ah soil horizons; deeper soil horizons contain mainly magnetically weak materials and are characterized by much lower values of susceptibility (up to 30 × 10-5 SI). Significant magnetic parameters (e.g., Curie temperature Tc) and SEM results of contaminated topsoils are comparable with magnetic parameters of atmospheric dust, collected (using high-volume samplers) at the same localities.

  17. Cover Crops Effects on Soil Chemical Properties and Onion Yield

    Directory of Open Access Journals (Sweden)

    Rodolfo Assis de Oliveira

    2016-01-01

    Full Text Available ABSTRACT Cover crops contribute to nutrient cycling and may improve soil chemical properties and, consequently, increase crop yield. The aim of this study was to evaluate cover crop residue decomposition and nutrient release, and the effects of these plants on soil chemical properties and on onion (Allium cepa L. yield in a no-tillage system. The experiment was carried out in an Inceptisol in southern Brazil, where cover crops were sown in April 2012 and 2013. In July 2013, shoots of weeds (WD, black oats (BO, rye (RY, oilseed radish (RD, oilseed radish + black oats (RD + BO, and oilseed radish + rye (RD + RY were cut at ground level and part of these material from each treatment was placed in litter bags. The litter bags were distributed on the soil surface and were collected at 0, 30, 45, 60, 75, and 90 days after distribution (DAD. The residues in the litter bags were dried, weighed, and ground, and then analyzed to quantify lignin, cellulose, non-structural biomass, total organic carbon (TOC, N, P, K, Ca, and Mg. In November 2012 and 2013, onion crops were harvested to quantify yield, and bulbs were classified according to diameter, and the number of rotted and flowering bulbs was determined. Soil in the 0.00-0.10 m layer was collected for chemical analysis before transplanting and after harvesting onion in December 2012 and 2013. The rye plant residues presented the highest half-life and they released less nutrients until 90 DAD. The great permanence of rye residue was considered a protection to soil surface, the opposite was observed with spontaneous vegetation. The cultivation and addition of dry residue of cover crops increased the onion yield at 2.5 Mg ha-1.

  18. Mechanical properties of lunar regolith and lunar soil simulant

    Science.gov (United States)

    Perkins, Steven W.

    1989-01-01

    Through the Surveyor 3 and 7, and Apollo 11-17 missions a knowledge of the mechanical properties of Lunar regolith were gained. These properties, including material cohesion, friction, in-situ density, grain-size distribution and shape, and porosity, were determined by indirect means of trenching, penetration, and vane shear testing. Several of these properties were shown to be significantly different from those of terrestrial soils, such as an interlocking cohesion and tensile strength formed in the absence of moisture and particle cementation. To characterize the strength and deformation properties of Lunar regolith experiments have been conducted on a lunar soil simulant at various initial densities, fabric arrangements, and composition. These experiments included conventional triaxial compression and extension, direct tension, and combined tension-shear. Experiments have been conducted at low levels of effective confining stress. External conditions such as membrane induced confining stresses, end platten friction and material self weight have been shown to have a dramatic effect on the strength properties at low levels of confining stress. The solution has been to treat these external conditions and the specimen as a full-fledged boundary value problem rather than the idealized elemental cube of mechanics. Centrifuge modeling allows for the study of Lunar soil-structure interaction problems. In recent years centrifuge modeling has become an important tool for modeling processes that are dominated by gravity and for verifying analysis procedures and studying deformation and failure modes. Centrifuge modeling is well established for terrestrial enginering and applies equally as well to Lunar engineering. A brief review of the experiments is presented in graphic and outline form.

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

    Science.gov (United States)

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

    2015-04-01

    soil, since there are more voids filled with air and water, increasing the viscous losses. Fellah et al. (2003) showed that porosity can be determined from phase speed and reflection coefficient. The propagation of acoustic waves in soil is investigated to develop a rapid method for the quantification of the porosity level of agricultural soils. In the present contribution, correlations are determined between the acoustic signatures of agricultural soil in function of its structural properties. In laboratory, compression tests are performed on unsaturated soil samples to reproduce different porosity levels. Ultrasonic pulses are sent through the considered samples. The propagated signals are treated in both time and frequency domains in order to determine the speed of the phase velocity and the reflection. Porosity is then determined and compared with water content measured by gravimetric method. Alaoui, A., Lipiec, J. & Gerke, H.H., 2011. A review of the changes in the soil pore system due to soil deformation: A hydrodynamic perspective. Soil and Tillage Research, 115-116, pp.1-15. Fellah Z.E.A., Berger S., Lauriks W., Depollier C., Aristegui C., Chapelon J.Y., 2003. Measuring the porosity and the tortuosity of porous materials via reflected waves at oblique incidence. The Journal of the Acoustical Society of America 113 (5), pp 2424-2433 Hamza, M.A. & Anderson, W.K., 2005. Soil compaction in cropping systems. Soil and Tillage Research, 82(2), pp.121-145. Lu, Z., 2005. Role of hysteresis in propagating acousitcs waves in soils. Geophysical Research Letter, pp.32:1-4. Lu, Z., Hickey, C.J. & Sabatier, J.M., 2004. Effects of compaction on the acoustic velocity in soils. Soil Science Society of America Journal, 68(1), pp.7-16. Lu, Z. & Sabatier, J.M., 2009. Effects of soil water potential and moisture content on sound speed. Soil Science Society of America Journal, 73(5), pp.1614-1625. Le Maitre, D.C., Kotzee, I.M. & O'Farrell, P.J., 2014. Impacts of land-cover change on

  20. Effects of land-use changes on soil properties : volcano watershed in Quito, Ecuador

    OpenAIRE

    Podwojewski, Pascal; Poulenard, J.; Janeau, Jean-Louis

    2015-01-01

    In the highlands of southern Colombia and northern Ecuador, soils developed on volcanic ash deposits have specific properties: high water retention, high hydraulic conductivity and high carbon (C) contents. The main role of the soils is to regulate the water available for the dense population living in the valleys. Soil properties and land use depend on their altitudes. Any important modification of land-use change has a serious effect on soil properties and consequently the ecosystem propert...

  1. Top quark property measurements at the LHC

    CERN Document Server

    Hawkings, Richard; The ATLAS collaboration

    2014-01-01

    Measurements of top quark properties performed at the Large Hadron Collider are reviewed, with a particular emphasis on top-pair charge asymmetries, spin correlations and polarization measurements performed by the ATLAS and CMS collaborations. The measurements are generally in good agreement with predictions from next-to-leading-order QCD calculations, and no deviations from Standard Model expectations have been seen.

  2. Impact of Soil Conservation Measures on Erosion Control and Soil Quality

    International Nuclear Information System (INIS)

    2011-10-01

    This publication summarises the lessons learnt from a FAO/IAEA coordinated research project on the impact of soil conservation measures on erosion control and soil quality over a five-year period across a wide geographic area and range of environments. It demonstrates the new trends in the use of fallout radionuclide-based techniques as powerful tools to assess the effectiveness of soil conservation measures. As a comprehensive reference material it will support IAEA Member States in the use of these techniques to identify practices that can enhance sustainable agriculture and minimize land degradation.

  3. Comparing the performance of various digital soil mapping approaches to map physical soil properties

    Science.gov (United States)

    Laborczi, Annamária; Takács, Katalin; Pásztor, László

    2015-04-01

    Spatial information on physical soil properties is intensely expected, in order to support environmental related and land use management decisions. One of the most widely used properties to characterize soils physically is particle size distribution (PSD), which determines soil water management and cultivability. According to their size, different particles can be categorized as clay, silt, or sand. The size intervals are defined by national or international textural classification systems. The relative percentage of sand, silt, and clay in the soil constitutes textural classes, which are also specified miscellaneously in various national and/or specialty systems. The most commonly used is the classification system of the United States Department of Agriculture (USDA). Soil texture information is essential input data in meteorological, hydrological and agricultural prediction modelling. Although Hungary has a great deal of legacy soil maps and other relevant soil information, it often occurs, that maps do not exist on a certain characteristic with the required thematic and/or spatial representation. The recent developments in digital soil mapping (DSM), however, provide wide opportunities for the elaboration of object specific soil maps (OSSM) with predefined parameters (resolution, accuracy, reliability etc.). Due to the simultaneous richness of available Hungarian legacy soil data, spatial inference methods and auxiliary environmental information, there is a high versatility of possible approaches for the compilation of a given soil map. This suggests the opportunity of optimization. For the creation of an OSSM one might intend to identify the optimum set of soil data, method and auxiliary co-variables optimized for the resources (data costs, computation requirements etc.). We started comprehensive analysis of the effects of the various DSM components on the accuracy of the output maps on pilot areas. The aim of this study is to compare and evaluate different

  4. The Impact of Soil Properties on Valley-Bottom Gully Form, Northwest Highlands of Ethiopia.

    Science.gov (United States)

    Amare, S. D.; Langendoen, E. J.; Keesstra, S.; van der Ploeg, M. J.; Steenhuis, T. S.; Tilahun, S. A.

    2017-12-01

    Gully erosion is an important environmental and food security challenge facing the world. Despite the immense damages resulting from gully erosion, comprehensive studies on the processes of gully formation and its management strategies are limited. This is especially true for valley-bottom gullies, which form under different conditions and are caused by different processes than hillslope gullies. A recent review on valley-bottom gully erosion causes and controlling factors identified that gully geomorphological processes, particularly related to gully bank retreat, governed gully occurrence and reclamations. However, most valley-bottom gully erosion studies do not consider gully bank stability and how it is impacted by soil hydrology and soil intrinsic properties. The aim is to analyze these impacts on gully bank retreat in the Koga river watershed, Ethiopia, for Nitisol and Vertisols, using field and numerical modeling approaches. Field observations showed gully network in Vertisols were greater than those in Nitisols. On the other hand, Nitisol gullies are wider and deeper than Vertisols. Monitoring of hydro-meteorological and soil data was started in June 2017 and will continue until the end of the 2017 rainy season (September) and for 2018 rainy periods as well. Thirty-six piezometers were installed at 4m average depth covering an area of 20 km2 near the gully reaches. Ground anchors were used to measure soil swelling and shrinkage. Soil moisture content and potential were measured using GS1 Soil Moisture sensors and MPS-6 Water Potential sensors. Gully bank soil physicochemical and engineering properties have been sampled and analyzed. Preliminary results from the early portion of the rainy season showed that most piezometers were already filled up with water. However, relatively deep (2m) water tables were recorded in piezometers located near the gully banks. The soil matric potential dropped from the onset of the rainy season (-6800 kPa ) towards the middle

  5. A noncontact laser system for measuring soil surface topography

    International Nuclear Information System (INIS)

    Huang, C.; White, I.; Thwaite, E.G.; Bendeli, A.

    1988-01-01

    Soil surface topography profoundly influences runoff hydrodynamics, soil erosion, and surface retention of water. Here we describe an optical noncontact system for measuring soil surface topography. Soil elevation is measured by projecting a laser beam onto the surface and detecting the position of the interception point. The optical axis of the detection system is oriented at a small angle to the incident beam. A low-power HeNe (Helium-Neon) laser is used as the laser source, a photodiode array is used as the laser image detector and an ordinary 35-mm single lens reflex camera provides the optical system to focus the laser image onto the diode array. A wide spectrum of measurement ranges (R) and resolutions are selectable, from 1 mm to 1 m. These are determined by the laser-camera distance and angle, the focal length of the lens, and the sensing length of the diode array and the number of elements (N) contained in the array. The resolution of the system is approximately R/2N. We show for the system used here that this resolution is approximately 0.2%. In the configuration selected, elevation changes of 0.16 mm could be detected over a surface elevation range of 87 mm. The sampling rate of the system is 1000 Hz, which permits soil surfaces to be measured at speeds of up to 1 m s −1 with measurements taken at 1-mm spacing. Measurements of individual raindrop impacts on the soil and of soil surfaces before and after rain show the versatility of the laser surface profiler, which has applications in studies of erosion processes, surface storage and soil trafficability

  6. The Behaviour of Laboratory Soil Electrical Resistivity Value under Basic Soil Properties Influences

    International Nuclear Information System (INIS)

    Hazreek, Z A M; Aziman, M; Azhar, A T S; Chitral, W D; Fauziah, A; Rosli, S

    2015-01-01

    Electrical resistivity method (ERM) was a popular indirect geophysical tools adopted in engineering, environmental and archaeological studies. In the past, results of the electrical resistivity value (ERV) were always subjected to a long discussion and debate among the related parties such as an engineers, geophysicists and geologists due to its lack of clarification and evidences in quantitative point of view. Most of the results produced in the past was always been justified using qualitative ways which difficult to be accept by certain parties. In order to reduce the knowledge gap between those parties, this study has performed a laboratory experiment of soil box resistivity test which supported by an additional basic geotechnical test as referred to particle size distribution test (d), moisture content test (w), density test (ρ bulk ) and Atterberg limit test (LL, PL and PI). The test was performed to establish a series of electrical resistivity value with different quantity of water content for Clayey SILT and Silty SAND soil. It was found that the ERV of Silty SAND (600 - 7300 Ωm) was higher than Clayey SILT (13 - 7700 Ωm) due to the different quantity of basic soil properties value obtained from the basic geotechnical test. This study was successfully demonstrated that the fluctuation of ERV has greatly influenced by the variations of the soil physical properties (d, w, ρ bulk , LL, PL and PI). Hence, the confidence level of ERV interpretation will be increasingly meaningful since it able to be proved by others parameter generated by laboratory direct test

  7. Nonlinear Changes in Soil Properties and Their Impact on Ecosystems

    Science.gov (United States)

    Chadwick, O. A.; Chorover, J. D.

    2001-12-01

    Soils are open systems that act as a membrane at Earth's surface. Water and dissolved acids are the main materials transferred into soils, whereas water and lithogenic solutes dominate the output with the net result being depletion of rock forming constituents such as silica and base cations that are also ecosystem nutrients. The time-dependent coupling of water flux and chemical reactions determines the nature of the colloidal phase that is responsible for nutrient retention. Pedogenesis is a biogeochemical process that is constrained by thermodynamics, but still maintains considerable flexibility as a result of parallel reaction kinetics and a spatially heterogeneous matrix. In the open system, there are many processes that are governed by nonlinear response to changes in environmental variables and/or internal soil properties. From a thermodynamic perspective, the chemistry of pedogenesis is characterized by a number of thresholds. Simultaneous acid-base, ion exchange, redox and mineral transformation reactions interact to determine the direction and rate of change. Over time, the reaction of atmospheric acids with soil bases changes the acid neutralizing capacity of soil to an extent that is controlled by the prevailing buffering reactions. The amount of buffering reaction and effect on pH depend on the nature of the reactive species, their relative amounts, and their respective rates of reaction. Ion exchange and surface complexation reactions consume protons in the short term but long-term buffering derives from mineral weathering. The nature of the governing reactions is such that soils are well buffered to pH change in the alkaline and acid regions but far less so in the neutral to slightly acid zones. In an analogous fashion, organic matter may drive oxidation-reduction processes through a stepwise consumption of electron acceptors (thereby producing thresholds). Mineralogical change tends to occur in a serial, irreversible fashion that, under favorable

  8. Effects of soil properties on natural radio-nuclides concentration in arid environment: a case study

    International Nuclear Information System (INIS)

    Khater, A.F.M.; Al-Sewaidan, H.A.I.; Al-Saif, A.S.; Diab, H.I.

    2008-01-01

    Soil samples were collected from an arid environment in the central region of Saudi Arabia, 28 samples from selected 14 locations in an agricultural farm. Two samples, one from cultivated land and the second from uncultivated land, of the same origin were collected from each location. This work aims at investigating the changes of soil properties due to dry-land use and its effects on naturally occurring radio-nuclides (NOR) concentration and distribution. The specific activity, in Bq/kg, of 226 Ra ( 238 U series), 228 gRa ( 232 Th series), 40 K and 137 Cs were measured using calibrated gamma-ray spectrometer. The soil physical and chemical properties [e.g. pH, EC, particle size distribution (clay, silt and sand percentages), CaCO 3 %, soluble cations (Ca, Mg, Na and K) and soluble anions (CO 3 , HCO 3 , Cl and SO 4 )] were determined. The radium equivalent activity, in Bq/kg, and absorbed dose rate one meter above the ground, in nGy/y, were calculated. Generally, there are not noticeable changes in soil properties due to agricultural activities or strong correlations between soil properties and NOR specific activities. That could be due to the sandy nature of the soil and the effects of adsorption-filtration processes on the behavior and the distribution pattern of NOR in arid environment. Therefore, the environmental impacts of different man-made activities on underground resources should be carefully considered due to the possible filtration behavior of different pollutants in dry-land environment. (author)(tk)

  9. Development of soil properties and nitrogen cycling in created wetlands

    Science.gov (United States)

    Wolf, K.L.; Ahn, C.; Noe, G.B.

    2011-01-01

    Mitigation wetlands are expected to compensate for the loss of structure and function of natural wetlands within 5–10 years of creation; however, the age-based trajectory of development in wetlands is unclear. This study investigates the development of coupled structural (soil properties) and functional (nitrogen cycling) attributes of created non-tidal freshwater wetlands of varying ages and natural reference wetlands to determine if created wetlands attain the water quality ecosystem service of nitrogen (N) cycling over time. Soil condition component and its constituents, gravimetric soil moisture, total organic carbon, and total N, generally increased and bulk density decreased with age of the created wetland. Nitrogen flux rates demonstrated age-related patterns, with younger created wetlands having lower rates of ammonification, nitrification, nitrogen mineralization, and denitrification potential than older created wetlands and natural reference wetlands. Results show a clear age-related trajectory in coupled soil condition and N cycle development, which is essential for water quality improvement. These findings can be used to enhance N processing in created wetlands and inform the regulatory evaluation of mitigation wetlands by identifying structural indicators of N processing performance.

  10. Soil-root Shear Strength Properties of Some Slope Plants

    International Nuclear Information System (INIS)

    Normaniza Osman; Mohamad Nordin Abdullah; Faisal Haji Ali

    2011-01-01

    Rapid development in hilly areas in Malaysia has become a trend that put a stress to the sloping area. It reduces the factor of safety by reducing the resistant force and therefore leads to slope failure. Vegetation plays a big role in reinforcement functions via anchoring the soils and forms a binding network within the soil layer that tied the soil masses together. In this research, three plant species namely Acacia mangium, Dillenia suffruticosa and Leucaena leucocaphala were assessed in term of their soil-root shear strength properties. Our results showed that Acacia mangium had the highest shear strength values, 30.4 kPa and 50.2 kPa at loads 13.3 kPa and 24.3 kPa, respectively. Leucaena leucocaphala showed the highest in cohesion factor, which was almost double the value in those of Dillenia suffruticosa and Acacia mangium. The root profile analysis indicated Dillenia suffruticosa exhibited the highest values in both root length density and root volume, whilst Leucaena leucocaphala had the highest average of root diameter. (author)

  11. Semi-Arid Plantation by Anatolian Black Pine and Its Effects on Soil Erosion and Soil Properties

    Directory of Open Access Journals (Sweden)

    Sezgin Hacisalihoglu

    2018-04-01

    Full Text Available In this study, the effects of Anatolian Black pine [(Pinus nigra Arn. subsp. pallasiana (Lamb. Holmboe] plantation on hydro-physical soil properties and soil loss were investigated. This study was carried out on the afforestation field of Anatolian Black Pine in the Gölbaşı district of Ankara province, which is included in the arid and semi-arid regions. Totally 48 soil sample in two soil depth level (0-20cm, 20-50cm were collected from forest (36 soil sample and barren (control area (12 soil sample. Hydro-physically important soil properties were analysed [Sand (%, Silt (%, Clay (%, Organic Matter (%, pH, Field Capacity (%, Wilting Point (%, Saturation (%, Available Water Holding Capacity (cm/cm Saturated Hydraulic Conductivity (cm/hr, Bulk Density (gr/cm3]. And soil loss in a unit area by using ABAG (Allgemeine Boden Abtrags Gleichung model was estimated. Soil properties and soil loss amount relations among the land use group were determined. Topsoil (0-20cm and subsoil (20-50cm properties except subsoil organic matter were significantly affected by land use group. Finally, Significant changes were found for annual soil loss amounts in a unit area. Avarage annual soil loss in planted area was found approximately 5.5 times less than barren area at 0-50 cm soil depth. Vegetation factor (C which is one of the most important components of the soil loss equation, has been significantly affected by afforestation in a short period of 40 years and thus it was a variable to reduce to soil loss.

  12. Greenhouse gases fluxes and soil thermal properties in a pasture in central Missouri.

    Science.gov (United States)

    Nkonglolo, Nsalambi Vakanda; Johnson, Shane; Schmidt, Kent; Eivazi, Frieda

    2010-01-01

    Fluctuations of greenhouse gases emissions and soil properties occur at short spatial and temporal scales, however, results are often reported for larger scales studies. We monitored CO2, CH4, and N2O fluxes and soil temperature (T), thermal conductivity (K), resistivity (R) and thermal diffusivity (D) from 2004 to 2006 in a pasture. Soil air samples for determination of CO2, CH4 and N20 concentrations were collected from static and vented chambers and analyzed within two hours of collection with a gas chromatograph. T, K, R and D were measured in-situ using a KD2 probe. Soil samples were also taken for measurements of soil chemical and physical properties. The pasture acted as a sink in 2004, a source in 2005 and again a sink of CH4 in 2006. CO2 and CH4 were highest, but N2O as well as T, K and D were lowest in 2004. Only K was correlated with CO2 in 2004 while T correlated with both N2O (r = 0.76, p = 0.0001) and CO2 (r = 0.88, p = 0.0001) in 2005. In 2006, all gases fluxes were significantly correlated with T, K and R when the data for the entire year were considered. However, an in-depth examination of the data revealed the existence of month-to-month shifts, lack of correlation and differing spatial structures. These results stress the need for further studies on the relationship between soil properties and gases fluxes. K and R offer a promise as potential controlling factors for greenhouse gases fluxes in this pasture.

  13. Intelligent estimation of spatially distributed soil physical properties

    Science.gov (United States)

    Iwashita, F.; Friedel, M.J.; Ribeiro, G.F.; Fraser, Stephen J.

    2012-01-01

    Spatial analysis of soil samples is often times not possible when measurements are limited in number or clustered. To obviate potential problems, we propose a new approach based on the self-organizing map (SOM) technique. This approach exploits underlying nonlinear relation of the steady-state geomorphic concave-convex nature of hillslopes (from hilltop to bottom of the valley) to spatially limited soil textural data. The topographic features are extracted from Shuttle Radar Topographic Mission elevation data; whereas soil textural (clay, silt, and sand) and hydraulic data were collected in 29 spatially random locations (50 to 75. cm depth). In contrast to traditional principal component analysis, the SOM identifies relations among relief features, such as, slope, horizontal curvature and vertical curvature. Stochastic cross-validation indicates that the SOM is unbiased and provides a way to measure the magnitude of prediction uncertainty for all variables. The SOM cross-component plots of the soil texture reveals higher clay proportions at concave areas with convergent hydrological flux and lower proportions for convex areas with divergent flux. The sand ratio has an opposite pattern with higher values near the ridge and lower values near the valley. Silt has a trend similar to sand, although less pronounced. The relation between soil texture and concave-convex hillslope features reveals that subsurface weathering and transport is an important process that changed from loss-to-gain at the rectilinear hillslope point. These results illustrate that the SOM can be used to capture and predict nonlinear hillslope relations among relief, soil texture, and hydraulic conductivity data. ?? 2011 Elsevier B.V.

  14. Soil hydraulic material properties and layered architecture from time-lapse GPR

    Science.gov (United States)

    Jaumann, Stefan; Roth, Kurt

    2018-04-01

    Quantitative knowledge of the subsurface material distribution and its effective soil hydraulic material properties is essential to predict soil water movement. Ground-penetrating radar (GPR) is a noninvasive and nondestructive geophysical measurement method that is suitable to monitor hydraulic processes. Previous studies showed that the GPR signal from a fluctuating groundwater table is sensitive to the soil water characteristic and the hydraulic conductivity function. In this work, we show that the GPR signal originating from both the subsurface architecture and the fluctuating groundwater table is suitable to estimate the position of layers within the subsurface architecture together with the associated effective soil hydraulic material properties with inversion methods. To that end, we parameterize the subsurface architecture, solve the Richards equation, convert the resulting water content to relative permittivity with the complex refractive index model (CRIM), and solve Maxwell's equations numerically. In order to analyze the GPR signal, we implemented a new heuristic algorithm that detects relevant signals in the radargram (events) and extracts the corresponding signal travel time and amplitude. This algorithm is applied to simulated as well as measured radargrams and the detected events are associated automatically. Using events instead of the full wave regularizes the inversion focussing on the relevant measurement signal. For optimization, we use a global-local approach with preconditioning. Starting from an ensemble of initial parameter sets drawn with a Latin hypercube algorithm, we sequentially couple a simulated annealing algorithm with a Levenberg-Marquardt algorithm. The method is applied to synthetic as well as measured data from the ASSESS test site. We show that the method yields reasonable estimates for the position of the layers as well as for the soil hydraulic material properties by comparing the results to references derived from ground

  15. Agroclimatic mapping of maize crop based on soil physical properties

    International Nuclear Information System (INIS)

    Dourado Neto, Durval; Sparovek, G.; Reichardt, K.; Timm, Luiz Carlos; Nielsen, D.R.

    2004-01-01

    With the purpose of estimating water deficit to forecast yield knowing productivity (potential yield), the water balance is useful tool to recommend maize exploration and to define the sowing date. The computation can be done for each region with the objective of mapping maize grain yield based on agro-climatic data and soil physical properties. Based on agro-climatic data, air temperature and solar radiation, a model was built to estimate the corn grain productivity (the energy conversion results in dry mass production). The carbon dioxide (CO 2 ) fixation by plants is related to gross carbohydrate (CH 2 O) production and solar radiation. The CO 2 assimilation by C4 plants depends on the photosynthetic active radiation and temperature. From agro-climatic data and soil physical properties, a map with region identification can be built for solar radiation, air temperature, rainfall, maize grain productivity and yield, potential and real evapo-transpiration and water deficit. The map allows to identify the agro-climatic and the soil physical restrictions. This procedure can be used in different spatial (farm to State) and temporal (daily to monthly data) scales. The statistical analysis allows to compare estimated and observed values in different situations to validate the model and to verify which scale is more appropriate

  16. Superconducting property measuring system by magnetization method

    International Nuclear Information System (INIS)

    Ikisawa, K.; Mori, T.; Takasu, N.

    1988-01-01

    Superconducting property measuring system (CMS-370B) for high temperature oxide superconductor has been developed. This system adopts magnetization measurement. The superconducting properties are able to be measured automatically and continuously changing the temperature and external magnetic field. The critical current density as a function of temperature and magnetic field of high temperature superconductor YBa 2 Cu 3 O 7-y (YBCO) has been measured. This paper reports how it was confirmed that this system having the high performance and the accuracy gave the significant contribution to the superconducting material development

  17. The influence of stony soil properties on water dynamics modeled by the HYDRUS model

    Directory of Open Access Journals (Sweden)

    Hlaváčiková Hana

    2018-06-01

    Full Text Available Stony soils are composed of two fractions (rock fragments and fine soil with different hydrophysical characteristics. Although stony soils are abundant in many catchments, their properties are still not well understood. This manuscript presents an application of the simple methodology for deriving water retention properties of stony soils, taking into account a correction for the soil stoniness. Variations in the water retention of the fine soil fraction and its impact on both the soil water storage and the bottom boundary fluxes are studied as well. The deterministic water flow model HYDRUS-1D is used in the study. The results indicate that the presence of rock fragments in a moderate-to-high stony soil can decrease the soil water storage by 23% or more and affect the soil water dynamics. Simulated bottom fluxes increased or decreased faster, and their maxima during the wet period were larger in the stony soil compared to the non-stony one.

  18. Integrating soil physical and biological properties in contrasting tillage systems in organic and conventional farming

    NARCIS (Netherlands)

    Crittenden, S.J.; Goede, de R.G.M.

    2016-01-01

    Though soil physical and soil biological properties are intrinsically linked in the soil environment they are often studied separately. This work adds value to analyses of soil biophysical quality of tillage systems under organic and conventional farming systems by correlating physical and

  19. Investigating the Effect of Biological Crusts on Some Biological Properties of Soil (Case Study: Qare Qir Rangelands of Golestan Province

    Directory of Open Access Journals (Sweden)

    J. Kakeh

    2016-09-01

    Full Text Available Introduction: Physical and biological soil crusts are the principal types of soil crusts. Physical and biological soil crusts are distributed in arid, semi-arid and sub-humid regions which constitute over 40% of the earth terrestrial surface. Biological soil crusts (BSCs result from an intimate association between soil particles and cyanobacteria, algae, fungi, lichens and mosses in different proportions which live on the surface, or in the immediately uppermost millimeters of soil. Some of the functions that BSCs influences include: water absorption and retention, nutrient retention, Carbon and nitrogen fixation, biological activate and hydrologic Status. BSCs are important from the ecological view point and their effects on the environment, especially in rangeland, and desert ecosystems and this caused which researchers have a special attention to this component of the ecosystems more than before. Materials and Methods: This study carried out in the Qara Qir rangelands of Golestan province, northeast of Iran (37º15′ - 37º23′ N &54º33′ -54º39′ E, to investigate the effects of BSCs on some of soil biological properties. Four sites including with and without BSCs cover were selected. Soil biological properties such as microbial populations, soil respiration, microbial biomass carbon and nitrogen, as well as, other effective properties such asorganic carbon percent, total nitrogen, electrical conductivity, and available water content were measured in depths of 0-5 and 5-15 cm of soil with four replications. The gathered data were analyzed by nested plot, and the mean values were compared by Duncan test. Results and Discussion: The results showed that organic carbon and water content were higher at the surface under BSCs, followed by 5-15 cm soils under BSCs. Both soil depths of uncrusted soils showed substantially lower organic carbon and water content than the BSC-covered soils. Total nitrogen was far higher in BSC-encrusted surface

  20. Variability and scaling of hydraulic properties for 200 Area soils, Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    Khaleel, R.; Freeman, E.J.

    1995-10-01

    Over the years, data have been obtained on soil hydraulic properties at the Hanford Site. Much of these data have been obtained as part of recent site characterization activities for the Environmental Restoration Program. The existing data on vadose zone soil properties are, however, fragmented and documented in reports that have not been formally reviewed and released. This study helps to identify, compile, and interpret all available data for the principal soil types in the 200 Areas plateau. Information on particle-size distribution, moisture retention, and saturated hydraulic conductivity (K{sub s}) is available for 183 samples from 12 sites in the 200 Areas. Data on moisture retention and K{sub s} are corrected for gravel content. After the data are corrected and cataloged, hydraulic parameters are determined by fitting the van Genuchten soil-moisture retention model to the data. A nonlinear parameter estimation code, RETC, is used. The unsaturated hydraulic conductivity relationship can subsequently be predicted using the van Genuchten parameters, Mualem`s model, and laboratory-measured saturated hydraulic conductivity estimates. Alternatively, provided unsaturated conductivity measurements are available, the moisture retention curve-fitting parameters, Mualem`s model, and a single unsaturated conductivity measurement can be used to predict unsaturated conductivities for the desired range of field moisture regime.

  1. Vertical profile measurements of soil air suggest immobilization of gaseous elemental mercury in mineral soil.

    Science.gov (United States)

    Obrist, Daniel; Pokharel, Ashok K; Moore, Christopher

    2014-02-18

    Evasion of gaseous elemental Hg (Hg(0)g) from soil surfaces is an important source of atmospheric Hg, but the volatility and solid-gas phase partitioning of Hg(0) within soils is poorly understood. We developed a novel system to continuously measure Hg(0)g concentrations in soil pores at multiple depths and locations, and present a total of 297 days of measurements spanning 14 months in two forests in the Sierra Nevada mountains, California, U.S. Temporal patterns showed consistent pore Hg(0)g concentrations below levels measured in the atmosphere (termed Hg(0)g immobilization), ranging from 66 to 94% below atmospheric concentrations throughout multiple seasons. The lowest pore Hg(0)g concentrations were observed in the deepest soil layers (40 cm), but significant immobilization was already present in the top 7 cm. In the absence of sinks or sources, pore Hg(0)g levels would be in equilibrium with atmospheric concentrations due to the porous nature of the soil matrix and gas diffusion. Therefore, we explain decreases in pore Hg(0)g in mineral soils below atmospheric concentrations--or below levels found in upper soils as observed in previous studies--with the presence of an Hg(0)g sink in mineral soils possibly related to Hg(0)g oxidation or other processes such as sorption or dissolution in soil water. Surface chamber measurements showing daytime Hg(0)g emissions and nighttime Hg(0)g deposition indicate that near-surface layers likely dominate net atmospheric Hg(0)g exchange resulting in typical diurnal cycles due to photochemcial reduction at the surface and possibly Hg(0)g evasion from litter layers. In contrast, mineral soils seem to be decoupled from this surface exchange, showing consistent Hg(0)g uptake and downward redistribution--although our calculations indicate these fluxes to be minor compared to other mass fluxes. A major implication is that once Hg is incorporated into mineral soils, it may be unlikely subjected to renewed Hg(0)g re-emission from

  2. Continuous measurements of soil radon under regular field conditions

    International Nuclear Information System (INIS)

    Font, LL

    1999-01-01

    Continuous soil radon measurements were performed in the frame of an European Community-radon network using the Clipperton II detector. It has been found that in some periods, soil radon levels obtained with one Clipperton II probe are very different from those obtained with another probe placed at the same depth but a short distance apart. It has been also found that the response of the probes to a sudden change of radon concentration is controlled by the diffusion process along the bottom tube of the probe. Therefore, this study shows that the experimental data can be attributed to the natural behaviour of soil radon

  3. Quantifying the Interactions Between Soil Thermal Characteristics, Soil Physical Properties, Hydro-geomorphological Conditions and Vegetation Distribution in an Arctic Watershed

    Science.gov (United States)

    Dafflon, B.; Leger, E.; Robert, Y.; Ulrich, C.; Peterson, J. E.; Soom, F.; Biraud, S.; Tran, A. P.; Hubbard, S. S.

    2017-12-01

    Improving understanding of Arctic ecosystem functioning and parameterization of process-rich hydro-biogeochemical models require advances in quantifying ecosystem properties, from the bedrock to the top of the canopy. In Arctic regions having significant subsurface heterogeneity, understanding the link between soil physical properties (incl. fraction of soil constituents, bedrock depth, permafrost characteristics), thermal behavior, hydrological conditions and landscape properties is particularly challenging yet is critical for predicting the storage and flux of carbon in a changing climate. This study takes place in Seward Peninsula Watersheds near Nome AK and Council AK, which are characterized by an elevation gradient, shallow bedrock, and discontinuous permafrost. To characterize permafrost distribution where the top of permafrost cannot be easily identified with a tile probe (due to rocky soil and/or large thaw layer thickness), we developed a novel technique using vertically resolved thermistor probes to directly sense the temperature regime at multiple depths and locations. These measurements complement electrical imaging, seismic refraction and point-scale data for identification of the various thermal behavior and soil characteristics. Also, we evaluate linkages between the soil physical-thermal properties and the surface properties (hydrological conditions, geomorphic characteristics and vegetation distribution) using UAV-based aerial imaging. Data integration and analysis is supported by numerical approaches that simulate hydrological and thermal processes. Overall, this study enables the identification of watershed structure and the links between various subsurface and landscape properties in representative Arctic watersheds. Results show very distinct trends in vertically resolved soil temperature profiles and strong lateral variations over tens of meters that are linked to zones with various hydrological conditions, soil properties and vegetation

  4. The effect of soilagrochemical properties on level of available phosphate in soil

    International Nuclear Information System (INIS)

    Zhang Yumei

    1985-01-01

    Superphosphate labelled with 32 P and 15 typies of soil were used to study the effect of various soil-agrochemical properties on the availability of phosphate. The level was figured with A value. The relations of A to soybean yield and soil-agro-chemical properties were analysed through Multiple regression

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

    NARCIS (Netherlands)

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

    2015-01-01

    Soil contamination with lead is a worldwide problem. Pb can cause adverse effects, but its mobility and availability in the terrestrial environment are strongly controlled by soil properties. The present study investigated the influence of different soil properties on the solubility of lead in

  6. Chemical, Biochemical, and Microbiological Properties of Soils from Abandoned and Extensively Cultivated Olive Orchards

    Directory of Open Access Journals (Sweden)

    A. M. Palese

    2013-01-01

    Full Text Available The abandonment of olive orchards is a phenomenon of great importance triggered mainly by economic and social causes. The aim of this study was to investigate some chemical, biochemical, and microbiological properties in a soil of a southern olive grove abandoned for 25 years. In order to define the effect of the long-term land abandonment on soil properties, an adjacent olive grove managed according to extensive practices was taken as reference (essentially minimum tillage and no fertilization. Soil organic matter, total nitrogen, and pH were significantly higher in the abandoned olive grove due to the absence of tillage and the natural inputs of organic matter at high C/N ratio which, inter alia, increased the number of cellulolytic bacteria and stimulated the activity of β-glucosidase, an indicator of a more advanced stage of soil evolution. The soil of the abandoned olive orchard showed a lower number of total bacteria and fungi and a lower microbial diversity, measured by means of the Biolog method, as a result of a sort of specialization trend towards low quality organic substrates. From this point of view, the extensive cultivation management seemed to not induce a disturbance to microbiological communities.

  7. Chemical, Biochemical, and Microbiological Properties of Soils from Abandoned and Extensively Cultivated Olive Orchards

    Science.gov (United States)

    Palese, A. M.; Magno, R.; Casacchia, T.; Curci, M.; Baronti, S.; Miglietta, F.; Crecchio, C.; Xiloyannis, C.; Sofo, A.

    2013-01-01

    The abandonment of olive orchards is a phenomenon of great importance triggered mainly by economic and social causes. The aim of this study was to investigate some chemical, biochemical, and microbiological properties in a soil of a southern olive grove abandoned for 25 years. In order to define the effect of the long-term land abandonment on soil properties, an adjacent olive grove managed according to extensive practices was taken as reference (essentially minimum tillage and no fertilization). Soil organic matter, total nitrogen, and pH were significantly higher in the abandoned olive grove due to the absence of tillage and the natural inputs of organic matter at high C/N ratio which, inter alia, increased the number of cellulolytic bacteria and stimulated the activity of β-glucosidase, an indicator of a more advanced stage of soil evolution. The soil of the abandoned olive orchard showed a lower number of total bacteria and fungi and a lower microbial diversity, measured by means of the Biolog method, as a result of a sort of specialization trend towards low quality organic substrates. From this point of view, the extensive cultivation management seemed to not induce a disturbance to microbiological communities. PMID:24348166

  8. Contribution of soil electric resistivity measurements to the studies on soil/grapevine water relations

    Directory of Open Access Journals (Sweden)

    Etienne Goulet

    2006-06-01

    Full Text Available The classical techniques that allow to quantify the soil water status such as the gravimetric method or the use of neutrons probes do not give access to the volume of soil explored by the plant root system. On the contrary, electric tomography can be used to have a global vision on the water exchange area between soil and plant. The measurement of soil electric resistivity, as a non destructive, spatially integrative technique, has recently been introduced into viticulture. The use of performing equipment and adapted software allows for rapid data processing and gives the possibility to spatialize the variations of soil texture or humidity in two or three dimensions. Soil electric resistivity has been tested for the last three years at the Experimental Unit on Grapevine and Vine, INRA, Angers, France, to study the water supply to the vine in different “terroir” conditions. Resistivity measurements were carried out with the resistivity meter Syscal R1+ (Iris Instruments, France equipped with 21 electrodes. Those electrodes were lined up on the soil surface in a direction perpendiculary to 5 grapevine rows with an electrode spacing of 0.5 m. and a dipole-dipole arrangement. Resistivity measurements were performed on the same place at different times in order to study soil moisture variations. This experimental set up has permitted to visualise the soil stratification and individualize some positive electric anomalies corresponding to preferential drying ; this desiccation could be attributed to grapevine root activity. The soil bulk subject to the water up-take could be defined more precisely and in some types of soil, available water may even be quantified. Terroir effect on grapevine root activity has also been shown up on two different experimental parcels through electric tomography and first results indicate that it is possible to monitor the effects of soil management (inter-row grassing or different rootstocks on the water supply to the

  9. Response of the soil physical properties to restoration techniques in limestone quarries

    Science.gov (United States)

    Luna Ramos, Lourdes; Miralles Mellado, Isabel; Vignozzi, Nadia; Solé-Benet, Albert

    2016-04-01

    The devastating effects of soil erosion in mining areas from arid/semiarid environments have prompted efforts geared toward an improvement of the soil physical conditions for a fast establishment of vegetal cover. Restoration practices that increase soil moisture content are essential in drylands where rainfall is irregular or insufficient in order to accelerate ecological restoration. The aim of this study was to analyse the influence of organic amendments and mulches on the soil porosity as well as their impact on infiltration, five years after the beginning of an experimental restoration from limestone quarries in Sierra de Gádor (Almería, SE Spain). Nine plots 15 x 5 m were prepared at the site in a completely randomized 2 x 3 factorial design. The first factor, organic amendment, had three levels: sewage sludge (SA), compost from domestic organic residues (CA) and no amendment (NA). The second factor, mulches, also had three levels: gravel (GM), woodchip (WM) and no mulch (NM). In each experimental plot 75 native plants (Macrochloa tenacissima, Anthyllis terniflora and Anthyllis cytisoides) were planted. Infiltration was determined from rainfall simulations and soil porosity was assessed by image analysis of soil thin sections. Total porosity and pores distribution were measured according to pore shape (regular, irregular and elongated) and size (transmission pores [50-500 μm] and fissures [>500 μm]). Natural undisturbed soils around the mine area were used as a reference soil (RS). Restoration treatments showed higher total porosity, fissures and elongated pores than RS and we observed the highest values in treatments with WM. This fact is due to the disruption caused by the application of treatments rather that a good soil structure. Each combination exhibited different values of transmission pores, being greater in the combinations of NA-GM, SA-NM and CA-WM. Infiltration increased with the increase of the total porosity, fissures and elongated pores

  10. Measuring environmental change in forest ecosystems by repeated soil sampling: a North American perspective

    Science.gov (United States)

    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.

  11. Measuring and modeling of soil N2O emissions - How well are we doing?

    Science.gov (United States)

    Butterbach-Bahl, K.; Ralf, K.; Werner, C.; Wolf, B.

    2017-12-01

    Microbial processes in soils are the primarily source of atmospheric N2O. Fertilizer use to boost food and feed production of agricultural systems as well as nitrogen deposition to natural and semi-natural ecosystems due to emissions of NOx and NH3 from agriculture and energy production and re-deposition to terrestrial ecosystems has likely nearly doubled the pre-industrial source strength of soils for atmospheric N2O. Quantifying soil emissions and identifying mitigation options is becoming a major focus in the climate debate as N2O emissions from agricultural soils are a major contributor to the greenhouse gas footprint of agricultural systems, with agriculture incl. land use change contributing up to 30% to total anthropogenic GHG emissions. The increasing number of annual datasets show that soil emissions a) are largely depended on soil N availability and thus e.g. fertilizer application, b) vary with management (e.g. timing of fertilization, residue management, tillage), c) depend on soil properties such as organic matter content and pH, e) are affected by plant N uptake, and e) are controlled by environmental factors such as moisture and temperature regimes. It is remarkable that the magnitude of annual emissions is largely controlled by short-term N2O pulses occurring due to fertilization, wetting and drying or freezing and thawing of soils. All of this contributes to a notorious variability of soil N2O emissions in space and time. Overcoming this variability for quantification of source strengths and identifying tangible mitigation options requires targeted measuring approaches as well as the translation of our knowledge on mechanisms underlying emissions into process oriented models, which finally might be used for upscaling and scenario studies. This paper aims at reviewing current knowledge on measurements, modelling and upscaling of soil N2O emissions, thereby identifying short comes and uncertainties of the various approaches and fields for future

  12. Influence of relief and vegetation on soil properties in a disturbed chernozem soil landscape

    Science.gov (United States)

    Raab, Thomas; Hirsch, Florian; Vasserman, Oleksandr; Raab, Alexandra; Naeth, Anne

    2017-04-01

    In central and southeastern Alberta, chernozems dominate the soil landscape and are divided into several groups that follow the climate gradient from Northwest to Southeast: Dark Grey Chernozems, Black Chernozems, Dark Brown Chernozems; Brown Chernozems. Principles controlling development and distribution of these chernozem subtypes along the ecotone transect are quite well known. However, intensive land use over the last century has affected soils that originally have formed under natural conditions during the Holocene in more than 10,000 years. There is a lack of knowledge regarding soil development in these landscapes on the decadal to centennial time scale. Within this time frame the most important factor of soil formation may be relief, although this has not been properly studied. This study aims to compare soil properties in a typical chernozem landscape where soils have been highly disturbed and parent materials have been re-arranged by surface coal mining. We hypothesize that within 50 years, soils develop with significant differences based on vegetation type and slope aspect. Our study site is the former Diplomat Mine near Forestburg, Alberta where spoils form a small scale ridge and graben topography. The south facing slopes of the piles are covered by grassland, whereas on the north exposition has trees and shrubs. Samples were taken from six sites with differences in topography and vegetation type. Diplomate T1 is at the top of the ridge with grassland, Diplomate S1 is on the southern slope with grassland, Diplomate N1 is on the northern slope with trees, and Diplomate N2 is on the northern slope with shrubs. For comparison we took samples from two sites without slope aspect. One site was an undisturbed grassland (Diplomate Z1) and the other sites were reclaimed piles (Diplomate R1). At each site, five soil profiles were examined and volumetrically sampled (250 cm3 steel ring) in steps of five centimeters to a depth of 30 centimeters. We present first

  13. Measured soil water concentrations of cadmium and zinc in plant pots and estimated leaching outflows from contaminated soils

    DEFF Research Database (Denmark)

    Holm, P.E.; Christensen, T.H.

    1998-01-01

    Soil water concentrations of cadmium and zinc were measured in plant pots with 15 contaminated soils which differed in origin, texture, pH (5.1-7.8) and concentrations of cadmium (0.2-17 mg Cd kg(-1)) and zinc (36-1300 mg Zn kg(-1)). The soil waters contained total concentrations of 0.5 to 17 mu g...... to 0.1% per year of the total soil content of cadmium and zinc. The measured soil water concentrations of cadmium and zinc did not correlate linearly with the corresponding soil concentrations but correlated fairly well with concentrations measured in Ca(NO(3))(2) extracts of the soils and with soil...... water concentrations estimated from soil concentrations and pH. Such concentration estimates may be useful for estimating amounts of cadmium and zinc being leached from soils....

  14. Testing fungistatic properties of soil-like substrate for growing plants in bioregenerative life support systems

    Science.gov (United States)

    Enzhu, Hu; Nesterenko, Elena; Liu, Professor Hong; Manukovsky, N. S.; Kovalev, Vladimir; Gurevich, Yu.; Kozlov, Vladimir; Khizhnyak, Serge; Xing, Yidong; Hu, Enzhu; Enzhu, Hu

    There are two ways of getting vegetable food in BLSS: in hydroponic culture and on soil substrates. In any case there is a chance that the plants will be affected by plant pathogenic microorganisms. The subject of the research was a soil-like substrate (SLS) for growing plants in a Bioregenerative Life Support System (BLSS). We estimated the fungistatic properties of SLS using test cultures of Bipolaris and Alternaria plant pathogenic fungi. Experiments were made with the samples of SLS, natural soil and sand (as control). We tested 2 samples of SLS produced by way of bioconversion of wheat and rice straw. We measured the disease severity of wheat seedlings and the incidence of common root rot in natural (non-infectious) background and man-made (infectious) conditions. The severity of disease on the SLS was considerably smaller both in non-infectious and infectious background conditions (8 and 12%) than on the natural soil (18 and 32%) and sand. It was the soil-like substrate that had the minimal value among the variants being compared (20% in non-infectious and 40% in infectious background conditions). This index in respect of the soil was 55 and 78%, correspondingly, and in respect of the sand - 60%, regardless of the background. It was found that SLS significantly suppressed conidia germination of Bipolaris soroikiniana (pwheat and rice straw.

  15. Diphenylarsinic acid contaminated soil remediation by titanium dioxide (P25) photocatalysis: Degradation pathway, optimization of operating parameters and effects of soil properties

    Energy Technology Data Exchange (ETDEWEB)

    Wang, A-nan [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Graduate School of Chinese Academy of Sciences, Beijing 100039 (China); Teng, Ying [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Hu, Xue-feng [Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003 (China); Wu, Long-hua; Huang, Yu-juan [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Luo, Yong-ming, E-mail: ymluo@yic.ac.cn [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003 (China); Christie, Peter [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China)

    2016-01-15

    Diphenylarsinic acid (DPAA) is formed during the leakage of arsenic chemical weapons in sites and poses a high risk to biota. However, remediation methods for DPAA contaminated soils are rare. Here, the photocatalytic oxidation (PCO) process by nano-sized titanium dioxide (TiO{sub 2}) was applied to degrade DPAA in soil. The degradation pathway was firstly studied, and arsenate was identified as the final product. Then, an orthogonal array experimental design of L{sub 9}(3){sup 4}, only 9 experiments were needed, instead of 81 experiments in a conventional one-factor-at-a-time, was used to optimize the operational parameters soil:water ratio, TiO{sub 2} dosage, irradiation time and light intensity to increase DPAA removal efficiency. Soil:water ratio was found to have a more significant effect on DPAA removal efficiency than other properties. The optimum conditions to treat 4 g soil with a DPAA concentration of 20 mg kg{sup −1} were found to be a 1:10 soil: water ratio, 40 mW cm{sup −2} light intensity, 5% TiO{sub 2} in soil, and a 3-hour irradiation time, with a removal efficiency of up to 82.7%. Furthermore, this method (except for a change in irradiation time from 3 to 1.5 h) was validated in nine different soils and the removal efficiencies ranged from 57.0 to 78.6%. Removal efficiencies were found to be negatively correlated with soil electrical conductivity, organic matter content, pH and total phosphorus content. Finally, coupled with electron spin resonance (ESR) measurement, these soil properties affected the generation of OH• by TiO{sub 2} in soil slurry. This study suggests that TiO{sub 2} photocatalytic oxidation is a promising treatment for removing DPAA from soil. - Highlights: • DPAA was degraded into arsenate through TiO{sub 2} (P25) photocatalytic oxidation. • Soil/water ratio was more influential on the removal of DPAA in soil by TiO{sub 2} (P25). • Soil properties affected the adsorption of DPAA and the generation of OH• by Ti

  16. Diphenylarsinic acid contaminated soil remediation by titanium dioxide (P25) photocatalysis: Degradation pathway, optimization of operating parameters and effects of soil properties

    International Nuclear Information System (INIS)

    Wang, A-nan; Teng, Ying; Hu, Xue-feng; Wu, Long-hua; Huang, Yu-juan; Luo, Yong-ming; Christie, Peter

    2016-01-01

    Diphenylarsinic acid (DPAA) is formed during the leakage of arsenic chemical weapons in sites and poses a high risk to biota. However, remediation methods for DPAA contaminated soils are rare. Here, the photocatalytic oxidation (PCO) process by nano-sized titanium dioxide (TiO_2) was applied to degrade DPAA in soil. The degradation pathway was firstly studied, and arsenate was identified as the final product. Then, an orthogonal array experimental design of L_9(3)"4, only 9 experiments were needed, instead of 81 experiments in a conventional one-factor-at-a-time, was used to optimize the operational parameters soil:water ratio, TiO_2 dosage, irradiation time and light intensity to increase DPAA removal efficiency. Soil:water ratio was found to have a more significant effect on DPAA removal efficiency than other properties. The optimum conditions to treat 4 g soil with a DPAA concentration of 20 mg kg"−"1 were found to be a 1:10 soil: water ratio, 40 mW cm"−"2 light intensity, 5% TiO_2 in soil, and a 3-hour irradiation time, with a removal efficiency of up to 82.7%. Furthermore, this method (except for a change in irradiation time from 3 to 1.5 h) was validated in nine different soils and the removal efficiencies ranged from 57.0 to 78.6%. Removal efficiencies were found to be negatively correlated with soil electrical conductivity, organic matter content, pH and total phosphorus content. Finally, coupled with electron spin resonance (ESR) measurement, these soil properties affected the generation of OH• by TiO_2 in soil slurry. This study suggests that TiO_2 photocatalytic oxidation is a promising treatment for removing DPAA from soil. - Highlights: • DPAA was degraded into arsenate through TiO_2 (P25) photocatalytic oxidation. • Soil/water ratio was more influential on the removal of DPAA in soil by TiO_2 (P25). • Soil properties affected the adsorption of DPAA and the generation of OH• by TiO_2.

  17. Nature's amazing biopolymer: basic mechanical and hydrological properties of soil affected by plant exudates

    Science.gov (United States)

    Naveed, Muhammad; Roose, Tiina; Raffan, Annette; George, Timothy; Bengough, Glyn; Brown, Lawrie; Keyes, Sam; Daly, Keith; Hallett, Paul

    2016-04-01

    Plant exudates are known to have a very large impact on soil physical properties through changes in mechanical and hydrological processes driven by long-chain polysaccharides and surface active compounds. Whilst these impacts are well known, the basic physical properties of these exudates have only been reported in a small number of studies. We present data for exudates obtained from barley roots and chia seeds