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1

Soil roughness, slope and surface storage relationship for impervious areas  

Science.gov (United States)

SummaryThe study of the relationships between surface roughness, local slope gradient and maximum volume of water storage in surface depressions is a fundamental element in the development of hydrological models to be used in soil and water conservation strategies. Good estimates of the maximum volume of water storage are important for runoff assessment during rainfall events. Some attempts to link surface storage to parameters such as indices of surface roughness and, more rarely, local gradient have been proposed by several authors with empirical equations often conflicting between them and usually based on a narrow range of slope gradients. This suggests care in selecting any of the proposed equations or models and invites one to verify the existence of more realistic experimental relationships, based on physical models of the surfaces and valid for a larger range of gradients. The aim of this study is to develop such a relation for predicting/estimating the maximum volume of water that a soil surface, with given roughness characteristics and local slope gradient, can store. Experimental work has been carried out in order to reproduce reliable rough surfaces able to maintain the following properties during the experimental activity: (a) impervious surface to avoid biased storage determination; (b) stable, un-erodible surfaces to avoid changes of retention volume during tests; (c) absence of hydrophobic behaviour. To meet the conditions a-c we generate physical surfaces with various roughness magnitude using plasticine (emulsion of non-expansible clay and oil). The plasticine surface, reproducing surfaces of arable soils, was then wetted and dirtied with a very fine timber sawdust. This reduced the natural hydrophobic behaviour of the plasticine to an undetectable value. Storage experiments were conducted with plasticine rough surfaces on top of large rigid polystyrene plates inclined at different slope gradient: 2%, 5%, 10%, 20%, 30%. Roughness data collected on the generated plasticine surfaces were successfully compared with roughness data collected on real soil surfaces for similar conditions. A set of roughness indices was computed for each surface using roughness profiles measured with a laser profile meter. Roughness indices included quantiles of the Abbot-Firestone curve, which is used in surface metrology for industrial application to characterize surface roughness in a non-parametric approach ( Whitehouse, 1994). Storage data were fitted with an empirical equation (double negative exponential of roughness and slope). Several roughness indices resulted well related to storage. The better results were obtained using the Abbot-Firestone curve parameter P100. Beside this storage empirical model (SEM) a geometrical model was also developed, trying to give a more physical basis to the result obtained so far. Depression geometry was approximated with spherical cups. A general physical model was derived (storage cup model - SCM). The cup approximation identifies where roughness elevation comes in and how it relates to slope gradient in defining depression volume. Moreover, the exponential decay used for assessing slope effect on storage volume in the empirical model of Eqs. (8) and (9) emerges as consistent with distribution of cup sizes.

Borselli, Lorenzo; Torri, Dino

2010-11-01

2

GENERATING HIGH QUALITY IMPERVIOUS COVER DATA  

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Nonpoint source pollution (NPS) from urban/ suburban areas is rapidly increasing as the population increases in the United States. Research in recent years has consistently shown a strong relationship between the percentage of impervious cover in a drainage basin and the health...

3

Prior-knowledge-based spectral mixture analysis for impervious surface mapping  

Energy Technology Data Exchange (ETDEWEB)

In this study, we developed a prior-knowledge-based spectral mixture analysis (PKSMA) to map impervious surfaces by using endmembers derived separately for high- and low-density urban regions. First, an urban area was categorized into high- and low-density urban areas, using a multi-step classification method. Next, in high-density urban areas that were assumed to have only vegetation and impervious surfaces (ISs), the Vegetation-Impervious model (V-I) was used in a spectral mixture analysis (SMA) with three endmembers: vegetation, high albedo, and low albedo. In low-density urban areas, the Vegetation-Impervious-Soil model (V-I-S) was used in an SMA analysis with four endmembers: high albedo, low albedo, soil, and vegetation. The fraction of IS with high and low albedo in each pixel was combined to produce the final IS map. The root mean-square error (RMSE) of the IS map produced using PKSMA was about 11.0%, compared to 14.52% using four-endmember SMA. Particularly in high-density urban areas, PKSMA (RMSE = 6.47%) showed better performance than four-endmember (15.91%). The results indicate that PKSMA can improve IS mapping compared to traditional SMA by using appropriately selected endmembers and is particularly strong in high-density urban areas.

Zhang, Jinshui; He, Chunyang; Zhou, Yuyu; Zhu, Shuang; Shuai, Guanyuan

2014-01-03

4

Performance of heterogeneous earthfill dams under earthquakes: optimal location of the impervious core  

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Earthfill dams are man-made geostructures which may be especially damaged by seismic loadings, because the soil skeleton they are made of suffers remarkable modifications in its mechanical properties, as well as changes of pore water pressure and flow of this water inside their pores, when subjected to vibrations. The most extreme situation is the dam failure due to soil liquefaction. Coupled finite element numerical codes are a useful tool to assess the safety of these dams. In this paper the application of a fully coupled numerical model, previously developed and validated by the authors, to a set of theoretical cross sections of earthfill dams with impervious core, is presented. All these dams are same height and have the same volume of impervious material at the core. The influence of the core location inside the dam on its response against seismic loading is numerically explored. The dams are designed as strictly stable under static loads. As a result of this research, a design recommendation on the location of the impervious core is obtained for this type of earth dams, on the basis of the criteria of minor liquefaction risk, minor soil degradation during the earthquake and minor crest settlement.

López-Querol, S.; Moreta, P. J. M.

2008-01-01

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Performance of heterogeneous earthfill dams under earthquakes: optimal location of the impervious core  

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Full Text Available Earthfill dams are man-made geostructures which may be especially damaged by seismic loadings, because the soil skeleton they are made of suffers remarkable modifications in its mechanical properties, as well as changes of pore water pressure and flow of this water inside their pores, when subjected to vibrations. The most extreme situation is the dam failure due to soil liquefaction. Coupled finite element numerical codes are a useful tool to assess the safety of these dams. In this paper the application of a fully coupled numerical model, previously developed and validated by the authors, to a set of theoretical cross sections of earthfill dams with impervious core, is presented. All these dams are same height and have the same volume of impervious material at the core. The influence of the core location inside the dam on its response against seismic loading is numerically explored. The dams are designed as strictly stable under static loads. As a result of this research, a design recommendation on the location of the impervious core is obtained for this type of earth dams, on the basis of the criteria of minor liquefaction risk, minor soil degradation during the earthquake and minor crest settlement.

S. López-Querol

2008-01-01

6

Effect and relevance of the artificial drainage system when assessing the hydrologic impact of the imperviousness distribution within the watershed  

Science.gov (United States)

Cities and urban growth have relevant environmental and social impacts, which could eventually be enhanced or reduced during the urban planning process. From the point of view of hydrology, impermeability and natural soil compaction are one of the main problems that urbanization brings to watershed. Previous studies demonstrate and quantify the impacts of the distribution of imperviousness in a watershed, both on runoff volumes and flow, and the quality and integrity of streams and receiving bodies. Moreover, some studies have investigated the optimal distribution of imperviousness, based on simulating different scenarios of land use change and its effects on runoff, mostly at the outlet of the watershed. However, these studies typically do not address the impact of artificial drainage system associated with the imperviousness scenarios, despite it is known that storm sewer coverage affects the flow accumulation and generation of flow hydrographs. This study seeks to quantify the effects and relevance of the artificial system when it comes to assess the hydrological impacts of the spatial distribution of imperviousness and to determine the characteristics of this influence. For this purpose, an existing model to generate imperviousness distribution scenarios is coupled with a model developed to automatically generate artificial drainage networks. These models are applied to a natural watershed to generate a variety of imperviousness and storm sewer layout scenarios, which are evaluate with a morphoclimatic instantaneous unit hydrograph model. We first tested the ability of this approach to represent the joint effects of imperviousness (i.e. level and distribution) and storm sewer coverage. We then quantified the effects of these variables on the hydrological response, considering also different return period in order to take into account the variability of the precipitation regime. Overall, we show that the layout and spatial coverage of the storm sewer system affect the hydrologic response, and that these effects depend on the degree of imperviousness and the characteristics of the precipitation. Results of this research improve our understanding on how urban planning decisions can contribute to minimize the hydrologic and environmental impacts of urban development.

Thenoux, M.; Gironas, J. A.; Mejia, A.

2013-12-01

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Global Land Survey Impervious Mapping Project Web Site  

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The Global Land Survey Impervious Mapping Project (GLS-IMP) aims to produce the first global maps of impervious cover at the 30m spatial resolution of Landsat. The project uses Global Land Survey (GLS) Landsat data as its base but incorporates training data generated from very high resolution commercial satellite data and using a Hierarchical segmentation program called Hseg. The web site contains general project information, a high level description of the science, examples of input and output data, as well as links to other relevant projects.

DeColstoun, Eric Brown; Phillips, Jacqueline

2014-01-01

8

Effect of Riparian Impervious Cover on Leaf Litter Decomposition Rates and Lotic Benthic Macroinvertebrate Diversity  

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Riparian impervious cover has been implicated in reducing benthic biodiversity. We examined the impact of impervious cover on the decomposition and colonization of leafpacks in 6 sites located on three streams. The six sites ranged in impervious cover, in the drainage basin from 98% upstream at Meeting of the Waters Creek to 25% upstream on Bolin Creek. 5g leafpacks of dogwood leaves (Cornus florida), were placed at each site on October 15, 2004 and 5 replicates per site were collected on Oct. 25, Nov. 8 and Nov. 22. Decomposition rates were highest (AFDM remaining lowest) where forested cover was greatest, and lowest where impervious cover was greatest. The diversity of the initial macroinvertebrate colonization was highest with least impervious cover, and was dominated by chironomids where impervious cover was greatest. The negative impact of increasing impervious cover on stream community diversity is supported by this study. The ecosystem level process of leaf litter decomposition is also negatively affected.

Reice, S. R.; Rognstad, R. L.

2005-05-01

9

Impervious surfaces and sewer pipe effects on stormwater runoff temperature  

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The warming effect of the impervious surfaces in urban catchment areas and the cooling effect of underground storm sewer pipes on stormwater runoff temperature are assessed. Four urban residential catchment areas in the Cities of Guelph and Kitchener, Ontario, Canada were evaluated using a combination of runoff monitoring and modelling. The stormwater level and water temperature were monitored at 10 min interval at the inlet of the stormwater management ponds for three summers 2009, 2010 and 2011. The warming effect of the ponds is also studied, however discussed in detail in a separate paper. An artificial neural network (ANN) model for stormwater temperature was trained and validated using monitoring data. Stormwater runoff temperature was most sensitive to event mean temperature of the rainfall (EMTR) with a normalized sensitivity coefficient (Sn) of 1.257. Subsequent levels of sensitivity corresponded to the longest sewer pipe length (LPL), maximum rainfall intensity (MI), percent impervious cover (IMP), rainfall depth (R), initial asphalt temperature (AspT), pipe network density (PND), and rainfall duration (D), respectively. Percent impervious cover of the catchment area (IMP) was the key parameter that represented the warming effect of the paved surfaces; sensitivity analysis showed IMP increase from 20% to 50% resulted in runoff temperature increase by 3 °C. The longest storm sewer pipe length (LPL) and the storm sewer pipe network density (PND) are the two key parameters that control the cooling effect of the underground sewer system; sensitivity analysis showed LPL increase from 345 to 966 m, resulted in runoff temperature drop by 2.5 °C.

Sabouri, F.; Gharabaghi, B.; Mahboubi, A. A.; McBean, E. A.

2013-10-01

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Generating Ground Reference Data for a Global Impervious Surface Survey  

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We are engaged in a project to produce a 30m impervious cover data set of the entire Earth for the years 2000 and 2010 based on the Landsat Global Land Survey (GLS) data set. The GLS data from Landsat provide an unprecedented opportunity to map global urbanization at this resolution for the first time, with unprecedented detail and accuracy. Moreover, the spatial resolution of Landsat is absolutely essential to accurately resolve urban targets such as buildings, roads and parking lots. Finally, with GLS data available for the 1975, 1990, 2000, and 2005 time periods, and soon for the 2010 period, the land cover/use changes due to urbanization can now be quantified at this spatial scale as well. Our approach works across spatial scales using very high spatial resolution commercial satellite data to both produce and evaluate continental scale products at the 30m spatial resolution of Landsat data. We are developing continental scale training data at 1m or so resolution and aggregating these to 30m for training a regression tree algorithm. Because the quality of the input training data are critical, we have developed an interactive software tool, called HSegLearn, to facilitate the photo-interpretation of high resolution imagery data, such as Quickbird or Ikonos data, into an impervious versus non-impervious map. Previous work has shown that photo-interpretation of high resolution data at 1 meter resolution will generate an accurate 30m resolution ground reference when coarsened to that resolution. Since this process can be very time consuming when using standard clustering classification algorithms, we are looking at image segmentation as a potential avenue to not only improve the training process but also provide a semi-automated approach for generating the ground reference data. HSegLearn takes as its input a hierarchical set of image segmentations produced by the HSeg image segmentation program [1, 2]. HSegLearn lets an analyst specify pixel locations as being either positive or negative examples, and displays a classification of the study area based on these examples. For our study, the positive examples are examples of impervious surfaces and negative examples are examples of non-impervious surfaces. HSegLearn searches the hierarchical segmentation from HSeg for the coarsest level of segmentation at which selected positive example locations do not conflict with negative example locations and labels the image accordingly. The negative example regions are always defined at the finest level of segmentation detail. The resulting classification map can be then further edited at a region object level using the previously developed HSegViewer tool [3]. After providing an overview of the HSeg image segmentation program, we provide a detailed description of the HSegLearn software tool. We then give examples of using HSegLearn to generate ground reference data and conclude with comments on the effectiveness of the HSegLearn tool.

Tilton, James C.; deColstoun, Eric Brown; Wolfe, Robert E.; Tan, Bin; Huang, Chengquan

2012-01-01

11

EFFECT OF BROKEN IMPERVIOUS IRON LAYER ON WATER AVAILABILITY TO SEMI-ARID NORTHERN GHANAIAN FERRIC LIXISOLS  

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Full Text Available Rainwater is not readily available to sandy loam Ghanaian ferric lixisols. In an attempt to increase water availability to Nyankpala ferric lixisols, their impervious iron pan was broken. Average yield (number of bags of maize from ferric lexisol with ironpan broken was compared with that with iron pan unbroken. At an average annual rainfall of 64.125 to 106.775 mm for Nyampkala, ferric lexisol with or without iron pan broken yielded similar quantity (20-25bgs/ha of maize. Breaking of ironpan alone cannot increase water availability to Nyankpala ferric lixisols. Measures other than the breaking of iron pan are needed to increase water availability to ferreiclesisols and similar soils. Research into sustainable technologies such as permanent amendments for increased soil water availability to ferric lixisol and similar soils is required.

Akwasi Asamoah

2013-03-01

12

A Tetrahedron-Based Endmember Selection Approach for Urban Impervious Surface Mapping  

Science.gov (United States)

The pixel purity index (PPI) and two-dimensional (2-D) scatter plots are two popular techniques for endmember extraction in remote sensing spectral mixture analysis, yet both suffer from one major drawback, that is, the selection of a final set of endmembers has to endure a cumbersome process of iterative visual inspection and human intervention, especially when a spectrally-complex urban scene is involved. Within the conceptual framework of a V-H-L-S (vegetation-high albedo-low albedo-soil) model, which is expanded from the classic V-I-S (vegetation-impervious surface-soil) model, a tetrahedron-based endmember selection approach combined with a multi-objective optimization genetic algorithm (MOGA) was designed to identify urban endmembers from multispectral imagery. The tetrahedron defining the enclosing volume of MNF-transformed pixels in a three-dimensional (3-D) space was algorithmically sought, so that the tetrahedral vertices can ideally match the four components of the adopted model. A case study with Landsat Enhanced Thematic Mapper Plus (ETM+) satellite imagery in Shanghai, China was conducted to verify the validity of the method. The method performance was compared with those of the traditional PPI and 2-D scatter plots approaches. The results indicated that the tetrahedron-based endmember selection approach performed better in both accuracy and ease of identification for urban surface endmembers owing to the 3-D visualization analysis and use of the MOGA.

Wang, Wei; Yao, Xinfeng; Zhai, Junpeng; Ji, Minhe

2014-01-01

13

Commonality of rainfall variables influencing suspended solids concentrations in storm runoff from three different urban impervious surfaces  

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Finding a common set of rainfall variables to explain the concentration of suspended solids in runoff from typical urban impervious surfaces has many applications in stormwater planning. This paper describes a statistical process to identify key explanatory variables to non-coarse particle (suspended solids Toowoomba, Australia. The dominant variables for all surfaces were rainfall depth and peak 6-min rainfall intensity. Storm duration, defined as the time period when rainfall intensity exceeds 0.25 mm/h and antecedent storm rainfall were also important predictors, but was less dominant. The regression model fitted to non-coarse particle concentration across all surfaces was proportional to rainfall depth raised to a negative power and peak 6-min rainfall intensity raised to a positive power; the proportionality constant varies by surface type. The form of this common model has a physical basis and is analogous to the modified universal soil loss equation widely used for soil loss estimation for non-urban areas.

Brodie, Ian M.; Dunn, Peter K.

2010-06-01

14

Estimating the extent of impervious surfaces and turf grass across large regions  

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The ability of researchers to accurately assess the extent of impervious and pervious developed surfaces, e.g., turf grass, using land-cover data derived from Landsat satellite imagery in the Chesapeake Bay watershed is limited due to the resolution of the data and systematic discrepancies between developed land-cover classes, surface mines, forests, and farmlands. Estimates of impervious surface and turf grass area in the Mid-Atlantic, United States that were based on 2006 Landsat-derived land-cover data were substantially lower than estimates based on more authoritative and independent sources. New estimates of impervious surfaces and turf grass area derived using land-cover data combined with ancillary information on roads, housing units, surface mines, and sampled estimates of road width and residential impervious area were up to 57 and 45% higher than estimates based strictly on land-cover data. These new estimates closely approximate estimates derived from authoritative and independent sources in developed counties.

Claggett, Peter R.; Irani, Frederick M.; Thompson, Renee L.

2013-01-01

15

Extraction of urban impervious surface information based on object-oriented technology  

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Impervious surface is an important part of urban underlying surface, as well as an important monitoring index for city ecological system and environment changes. However, accurate impervious surface extraction is still a challenge. This paper uses the color, shape and overall heterogeneity features from the high spatial resolution remote sensing image to extract the impervious surface. An edge-based image segmentation algorithm is put forward to fuse heterogeneous objects which integrates edge features and multi-scale segmentation algorithm and uses the edge information to guide image objects generation. Results showed that this method can greatly improve the accuracy of image segmentation. Accuracy assessment indicated that the overall impervious surface classification accuracy and a Kappa coefficient yield 87% and 0.84, respectively.

Liu, Aixia; Zhao, Xiaojie; Wang, Jing; He, Ting

2013-10-01

16

Atmospheric mercury accumulation and washoff processes on impervious urban surfaces  

Science.gov (United States)

The deposition and transport of mercury (Hg) has been studied extensively in rural environments but is less understood in urbanized catchments, where elevated atmospheric Hg concentrations and impervious surfaces may efficiently deliver Hg to waterways in stormwater runoff. We determined the rate at which atmospheric Hg accumulates on windows, identified the importance of washoff in removing accumulated Hg, and measured atmospheric Hg concentrations to help understand the relationship between deposition and surface accumulation. The main study location was Toronto, Ontario. Similar samples were also collected from Austin, Texas for comparison of Hg accumulation between cities. Windows provided a good sampling surface because they are ubiquitous in urban environments and are easy to clean/blank allowing the assessment of contemporary Hg accumulation. Hg Accumulation rates were spatially variable ranging from 0.82 to 2.7 ng m -2 d -1 in Toronto and showed similar variability in Austin. The highest accumulation rate in Toronto was at the city center and was 5× higher than the rural comparison site (0.58 ng m -2 d -1). The atmospheric total gaseous mercury (TGM) concentrations were less than 2× higher between the rural and urban locations (1.7 ± 0.3 and 2.7 ± 1.1 ng m -3, respectively). The atmospheric particulate bound fraction (HgP), however, was more than 3× higher between the rural and urban sites, which may have contributed to the higher urban Hg accumulation rates. Windows exposed to precipitation had 73 ± 9% lower accumulation rates than windows sheltered from precipitation. Runoff collected from simulated rain events confirmed that most Hg accumulated on windows was easily removed and that most of the Hg in washoff was HgP. Our results indicate that the Hg flux from urban catchments will respond rapidly to changes in atmospheric concentrations due to the mobilization of the majority of the surface accumulated Hg during precipitation events.

Eckley, Chris S.; Branfireun, Brian; Diamond, Miriam; Van Metre, Peter C.; Heitmuller, Frank

17

An approach for mapping large-area impervious surfaces: Synergistic use of Landsat-7 ETM+ and high spatial resolution imagery  

Science.gov (United States)

A wide range of urban ecosystem studies, including urban hydrology, urban climate, land use planning, and resource management, require current and accurate geospatial data of urban impervious surfaces. We developed an approach to quantify urban impervious surfaces as a continuous variable by using multisensor and multisource datasets. Subpixel percent impervious surfaces at 30-m resolution were mapped using a regression tree model. The utility, practicality, and affordability of the proposed method for large-area imperviousness mapping were tested over three spatial scales (Sioux Falls, South Dakota, Richmond, Virginia, and the Chesapeake Bay areas of the United States). Average error of predicted versus actual percent impervious surface ranged from 8.8 to 11.4%, with correlation coefficients from 0.82 to 0.91. The approach is being implemented to map impervious surfaces for the entire United States as one of the major components of the circa 2000 national land cover database.

Yang, L.; Huang, C.; Homer, C. G.; Wylie, B. K.; Coan, M. J.

2003-01-01

18

Impacts of impervious cover, water withdrawals, and climate change on river flows in the Conterminous US  

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Full Text Available Rivers are essential to aquatic ecosystem and societal sustainability, but are increasingly impacted by water withdrawals, land use change, and climate change. The relative and cumulative effects of these stressors on continental river flows are relatively unknown. In this study, we used an integrated water balance and flow routing model to evaluate the impacts of 2010 impervious cover and water withdrawal on river flow across the Conterminous US at the 8-digit Hydrologic Unit Code (HUC watershed scale. We then estimated the impacts of projected change in withdrawals, impervious cover, and climate under the B1 "low" and A2 "high" emission scenarios on river flows by 2060. Our results suggest that compared to no impervious cover, 2010 levels of impervious cover increased river flows by 9.9% on average with larger impacts in and downstream of major metropolitan areas. In contrast, compared to no water withdrawals, 2010 withdrawals decreased river flows by 1.4% on average with larger impacts in heavily irrigated arid regions of Western US. By 2060, impacts of climate change were predicted to overwhelm the potential gain in river flow due to future changes in impervious cover and add to the potential reduction in river flows from withdrawals, decreasing mean annual river flows from 2010 levels by 16% on average. However, increases in impervious cover by 2060 may offset the impact of climate change during the growing season in some watersheds. Large water withdrawals will aggravate the predicted impact of climate change on river flows, particularly in the Western US. Given that the impacts of land use, withdrawals and climate may be either additive or offsetting in different magnitudes, integrated and spatially explicit modelling and management approaches are necessary to effectively manage water resources for aquatic life and human use in the face of global change.

P. V. Caldwell

2012-04-01

19

Synergistic using medium-resolution and high-resolution remote sensing imagery to extract impervious surface for Dianci Basin  

Science.gov (United States)

The knowledge of impervious surfaces, especially the magnitude, location, geometry, spatial pattern of impervious surfaces, is significant to urban ecosystem studies, including urban hydrology, urban climate, land use planning and resource management.Impervious surface area (ISA) is considered a key indicator of environmental quality and can be used to address complex urban environmental issues, particularly those related to the health of urban watersheds. ISA is also an indicator of non-point source pollution or polluted runoff. Remote sensing offers a consistent framework for representing spatial patterns and rates of urbanization over time through accurate observations of impervious surface area. Most of the existing methods of extracting impervious surface based on remote sensing concentrate on an urban scale, but the rapid and accurate methods of extracting impervious surfaces in a basin scale are nearly nonexistent in China and abroad. In recent years,with the rapid urbanization especially surrounding the Dianchi water body, the impervious surface coverage rate also grows rapidly and results in severe degradation of basin water environment within Dianchi watershed. In this study, we developed an approach to extract impervious surface for Dianci Basin by synergistic using medium-resolution and high-resolution remote sensing imagery. Subpixel percent impervious surfaces at Thematic Mapper (TM) images were mapped using the classification and regression tree(CART) algorithm. Sub-pixel impervious surfaces at 30m resolution were mapped in this study area through regression tree models. The estimated ISA results were evaluated through independent ISA reference data derived from high resolution QuickBird. The results prove the suitability of the approach for a widely automated and mapping of impervious surfaces in a basin scale.

Hong, Liang; Yang, Kun; Deng, Ming; Liu, Cun

2014-03-01

20

Impacts of impervious cover, water withdrawals, and climate change on river flows in the conterminous US  

Science.gov (United States)

Rivers are essential to aquatic ecosystem and societal sustainability, but are increasingly impacted by water withdrawals, land-use change, and climate change. The relative and cumulative effects of these stressors on continental river flows are relatively unknown. In this study, we used an integrated water balance and flow routing model to evaluate the impacts of impervious cover and water withdrawal on river flow across the conterminous US at the 8-digit Hydrologic Unit Code (HUC) watershed scale. We then estimated the impacts of projected change in withdrawals, impervious cover, and climate under the B1 "Low" and A2 "High" emission scenarios on river flows by 2060. Our results suggest that compared to no impervious cover, 2010 levels of impervious cover increased river flows by 9.9% on average with larger impacts in and downstream of major metropolitan areas. In contrast, compared to no water withdrawals, 2005 withdrawals decreased river flows by 1.4% on average with larger impacts in heavily irrigated arid regions of Western US. By 2060, impacts of climate change were predicted to overwhelm the potential gain in river flow due to future changes in impervious cover and add to the potential reduction in river flows from withdrawals, decreasing mean annual river flows from 2010 levels by 16% on average. However, increases in impervious cover by 2060 may offset the impact of climate change during the growing season in some watersheds. Large water withdrawals will aggravate the predicted impact of climate change on river flows, particularly in the Western US. Predicted ecohydrological impacts of land cover, water withdrawal, and climate change will likely include alteration of the terrestrial water balance, stream channel habitat, riparian and aquatic community structure in snow-dominated basins, and fish and mussel extirpations in heavily impacted watersheds. These changes may also require new infrastructure to support increasing anthropogenic demand for water, relocation of agricultural production, and/or water conservation measures. Given that the impacts of land use, withdrawals and climate may be either additive or offsetting in different magnitudes, integrated and spatially explicit modeling and management approaches are necessary to effectively manage water resources for aquatic life and human use in the face of global change.

Caldwell, P. V.; Sun, G.; McNulty, S. G.; Cohen, E. C.; Moore Myers, J. A.

2012-08-01

 
 
 
 
21

Impacts of impervious cover, water withdrawals, and climate change on river flows in the conterminous US  

Directory of Open Access Journals (Sweden)

Full Text Available Rivers are essential to aquatic ecosystem and societal sustainability, but are increasingly impacted by water withdrawals, land-use change, and climate change. The relative and cumulative effects of these stressors on continental river flows are relatively unknown. In this study, we used an integrated water balance and flow routing model to evaluate the impacts of impervious cover and water withdrawal on river flow across the conterminous US at the 8-digit Hydrologic Unit Code (HUC watershed scale. We then estimated the impacts of projected change in withdrawals, impervious cover, and climate under the B1 "Low" and A2 "High" emission scenarios on river flows by 2060. Our results suggest that compared to no impervious cover, 2010 levels of impervious cover increased river flows by 9.9% on average with larger impacts in and downstream of major metropolitan areas. In contrast, compared to no water withdrawals, 2005 withdrawals decreased river flows by 1.4% on average with larger impacts in heavily irrigated arid regions of Western US. By 2060, impacts of climate change were predicted to overwhelm the potential gain in river flow due to future changes in impervious cover and add to the potential reduction in river flows from withdrawals, decreasing mean annual river flows from 2010 levels by 16% on average. However, increases in impervious cover by 2060 may offset the impact of climate change during the growing season in some watersheds. Large water withdrawals will aggravate the predicted impact of climate change on river flows, particularly in the Western US. Predicted ecohydrological impacts of land cover, water withdrawal, and climate change will likely include alteration of the terrestrial water balance, stream channel habitat, riparian and aquatic community structure in snow-dominated basins, and fish and mussel extirpations in heavily impacted watersheds. These changes may also require new infrastructure to support increasing anthropogenic demand for water, relocation of agricultural production, and/or water conservation measures. Given that the impacts of land use, withdrawals and climate may be either additive or offsetting in different magnitudes, integrated and spatially explicit modeling and management approaches are necessary to effectively manage water resources for aquatic life and human use in the face of global change.

P. V. Caldwell

2012-08-01

22

Quantifying sub-pixel urban impervious surface through fusion of optical and inSAR imagery  

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In this study, we explored the potential to improve urban impervious surface modeling and mapping with the synergistic use of optical and Interferometric Synthetic Aperture Radar (InSAR) imagery. We used a Classification and Regression Tree (CART)-based approach to test the feasibility and accuracy of quantifying Impervious Surface Percentage (ISP) using four spectral bands of SPOT 5 high-resolution geometric (HRG) imagery and three parameters derived from the European Remote Sensing (ERS)-2 Single Look Complex (SLC) SAR image pair. Validated by an independent ISP reference dataset derived from the 33 cm-resolution digital aerial photographs, results show that the addition of InSAR data reduced the ISP modeling error rate from 15.5% to 12.9% and increased the correlation coefficient from 0.71 to 0.77. Spatially, the improvement is especially noted in areas of vacant land and bare ground, which were incorrectly mapped as urban impervious surfaces when using the optical remote sensing data. In addition, the accuracy of ISP prediction using InSAR images alone is only marginally less than that obtained by using SPOT imagery. The finding indicates the potential of using InSAR data for frequent monitoring of urban settings located in cloud-prone areas. Copyright ?? 2009 by Bellwether Publishing, Ltd. All right reserved.

Yang, L.; Jiang, L.; Lin, H.; Liao, M.

2009-01-01

23

Contribution of directly connected and isolated impervious areas to urban drainage network hydrographs  

Directory of Open Access Journals (Sweden)

Full Text Available This paper addresses the mass balance error observed in runoff hydrographs in urban watersheds by introducing assumptions regarding the contribution of infiltrated rainfall from pervious areas and isolated impervious area (IIA to the runoff hydrograph. Rainfall infiltrating into pervious areas has been assumed not to contribute to the runoff hydrograph until Hortonian excess rainfall occurs. However, mass balance analysis in an urban watershed indicates that rainfall infiltrated to pervious areas can contribute directly to the runoff hydrograph, thereby offering an explanation for the long hydrograph tail commonly observed in runoff from urban storm sewers. In this study, a hydrologic analysis based on the width function is introduced, with two types of width functions obtained from both pervious and impervious areas, respectively. The width function can be regarded as the direct interpretation of the network response. These two width functions are derived to obtain distinct response functions for directly connected impervious areas (DCIA, IIA, and pervious areas. The results show significant improvement in the estimation of runoff hydrographs and suggest the need to consider the flow contribution from pervious areas to the runoff hydrograph. It also implies that additional contribution from flow paths through joints and cracks in sewer pipes needs to be taken into account to improve the estimation of runoff hydrographs in urban catchments.

Y. Seo

2013-09-01

24

Contribution of directly connected and isolated impervious areas to urban drainage network hydrographs  

Science.gov (United States)

This paper addresses the mass balance error observed in runoff hydrographs in urban watersheds by introducing assumptions regarding the contribution of infiltrated rainfall from pervious areas and isolated impervious area (IIA) to the runoff hydrograph. Rainfall infiltrating into pervious areas has been assumed not to contribute to the runoff hydrograph until Hortonian excess rainfall occurs. However, mass balance analysis in an urban watershed indicates that rainfall infiltrated to pervious areas can contribute directly to the runoff hydrograph, thereby offering an explanation for the long hydrograph tail commonly observed in runoff from urban storm sewers. In this study, a hydrologic analysis based on the width function is introduced, with two types of width functions obtained from both pervious and impervious areas, respectively. The width function can be regarded as the direct interpretation of the network response. These two width functions are derived to obtain distinct response functions for directly connected impervious areas (DCIA), IIA, and pervious areas. The results show significant improvement in the estimation of runoff hydrographs and suggest the need to consider the flow contribution from pervious areas to the runoff hydrograph. It also implies that additional contribution from flow paths through joints and cracks in sewer pipes needs to be taken into account to improve the estimation of runoff hydrographs in urban catchments.

Seo, Y.; Choi, N.-J.; Schmidt, A. R.

2013-09-01

25

Contribution of directly connected and isolated impervious areas to urban drainage network hydrographs  

Directory of Open Access Journals (Sweden)

Full Text Available This paper addresses the mass balance error observed in runoff hydrographs in urban watersheds by introducing assumptions regarding the contribution of infiltrated rainfall from pervious areas and isolated impervious area (IIA to the runoff hydrograph. Rainfall infiltrating into pervious areas has been assumed not to contribute to the runoff hydrograph until Hortonian excess rainfall occurs. However, mass balance analysis in an urban watershed indicates that rainfall infiltrated to pervious areas can contribute to direct runoff hydrograph, thereby offering an explanation for the long hydrograph tail commonly observed in runoff from urban storm sewers. In this study, a hydrologic analysis based on the width function is introduced, with two types of width functions obtained from both pervious and impervious areas, respectively. The width function can be regarded as the direct interpretation of the network response. These two width functions are derived to obtain distinct response functions for directly connected impervious areas (DCIA, IIA, and pervious areas. The results show significant improvement in the estimation of runoff hydrographs and suggest the need to consider the flow contribution from pervious areas to the runoff hydrograph. It also implies that additional contribution from flow paths through joints and cracks in sewer pipes needs to be taken into account to improve the estimation of runoff hydrographs in urban catchments.

Y. Seo

2013-05-01

26

Importance of High-Resolution LiDAR Data in Modeling Runoff Levels Over Impervious Surfaces  

Science.gov (United States)

Directly connected impervious areas collect and deliver unfiltered runoff to modified and impacted waterways. Modeling water flow over the landscape is an effective method of observing drainage patterns and predicting pollutant and sediment loadings. Improved models applying high-resolution elevation data can identify key areas with high pollutant output. This is a crucial issue in the Lake Tahoe Basin where lakeshore urban development has increased and lake clarity has been declining for years. This study aims to evaluate an integrated LiDAR and GIS-based modeling approach that uses a fine-scaled ground surface and impervious surface connectivity to predict the pollutant load in the Lake Tahoe Basin This study produced a fine-scaled surface model of nine subset catchments in the South Tahoe basin, including areas of low (below 20%), medium (30% to 50%) and high (above 50%) impervious surface cover. Our method integrated LiDAR, multispectral imagery, and GIS data to develop accurate terrain models, hydrologic routing, and directly connected impervious area layers for the Lake Tahoe basin. The high-density ground and object elevation data collected using Light Detection and Ranging (LiDAR) creates an accurate picture of water flow over the land, and obstacles to the flow such as buildings. High-resolution LiDAR data was obtained from the Round 10 Lake Tahoe Southern Nevada Public Land Management capital program from the year 2010. This data was processed to create a digital elevation model of the ground surface. Land use classification used object height information from the LiDAR cloud, NAIP 4-band images with 1-meter resolution and a normalized difference vegetation index image derived from the NAIP imagery. The US Army Core of Engineers hydrologic modeling system (HEC-HMS) will be used to model runoff. Based on long-term simulations the effect of directly connected impervious area on rainfall-runoff characteristics for the South Lake Tahoe catchments will be evaluated. Similar scenarios will be run on data derived from 10-meter resolution USGS elevation models. Regression analyses will be used to compare the simulation results derived using LiDAR data inputs to the results obtained using lower-resolution USGS elevation models and to observed monitoring data.

Melosh, C.; Rao, M.

2013-12-01

27

Ecologically relevant geomorphic attributes of streams are impaired by even low levels of watershed effective imperviousness  

Science.gov (United States)

Urbanization almost inevitably results in changes to stream morphology. Understanding the mechanisms for such impacts is a prerequisite to minimizing stream degradation and achieving restoration goals. However, investigations of urban-induced changes to stream morphology typically use indicators of watershed urbanization that may not adequately represent degrading mechanisms and commonly focus on geomorphic attributes such as channel dimensions that may be of little significance to the ecological goals for restoration. We address these shortcomings by testing if a measure characterizing urban stormwater drainage system connections to streams (effective imperviousness, EI) is a better predictor of change to ecologically relevant geomorphic attributes than a more general measure of urban density (total imperviousness, TI). We test this for 17 sites in independent watersheds across a gradient of urbanization. We found that EI was a better predictor of all geomorphic variables tested than was TI. Bank instability was positively correlated with EI, while width/depth (a measure of channel incision), bedload sediment depth, and frequency of bars, benches, and large wood were negatively correlated. Large changes in all geomorphic variables were detected at very low levels of EI (Urbanization influences stream morphology more than any other land use (Douglas, 2011): it alters hydrology and sediment inputs leading to deepening and widening of streams (Chin, 2006). Concomitantly, urbanization often directly impairs stream morphology through channel and riparian zone interventions, e.g., culverts (Hawley et al., 2012), rock protection (Vietz et al., 2012b), and constricted floodplains (Gurnell et al., 2007). These changes to channel geomorphology in turn contribute to poor in-stream ecological condition (Morley and Karr, 2002; Walsh et al., 2005b; Gurnell et al., 2007; Elosegi et al., 2010).The common conception is that channels undergo gross morphologic alterations if > 10-20% of their watershed is covered by impervious surfaces (total imperviousness, TI; Bledsoe and Watson, 2001; Chin, 2006; Table 1). Many of these studies may, however, underestimate the influence of urbanization by using insensitive channel metrics and assessing streams in early stages of urbanization. Most importantly, TI, as a measure of urban density, may not adequately represent the way in which urbanization alters the master variables of flow and sediment within a watershed.Hydrologists have long recognized that, rather than the proportion of impervious cover within a watershed, it is the proportion that is directly connected to the stream through stormwater drainage systems that may be a better predictor of urban-induced hydrologic change (Leopold, 1968). Referred to as effective imperviousness (EI) the proportion of impervious cover directly connected to the stream through stormwater drainage systems may also be a better predictor of geomorphic response than is TI. Over the last decade a direct measure of EI has been found to be a better predictor of ecological response in urban streams (Walsh et al., 2012), but use of such a metric has not found its way into geomorphic studies even though TI has been found to be ineffective (e.g., Bledsoe et al.

Vietz, Geoff J.; Sammonds, Michael J.; Walsh, Christopher J.; Fletcher, Tim D.; Rutherfurd, Ian D.; Stewardson, Michael J.

2014-02-01

28

Soils  

Soils Here you can find a practical guide to soil assessment which can help you increase income and save money. We've developed Thinksoils in consultation with farmers, soil surveyors and agricultural advisors to provide advice on good soil management. About soil and 'thinksoils' Soil is your key…

29

Synergistic use of optical and InSAR data for urban impervious surface mapping: A case study in Hong Kong  

Science.gov (United States)

A wide range of urban ecosystem studies, including urban hydrology, urban climate, land use planning and watershed resource management, require accurate and up-to-date geospatial data of urban impervious surfaces. In this study, the potential of the synergistic use of optical and InSAR data in urban impervious surface mapping at the sub-pixel level was investigated. A case study in Hong Kong was conducted for this purpose by applying a classification and regression tree (CART) algorithm to SPOT 5 multispectral imagery and ERS-2 SAR data. Validated by reference data derived from high-resolution colour-infrared (CIR) aerial photographs, our results show that the addition of InSAR feature information can improve the estimation of impervious surface percentage (ISP) in comparison with using SPOT imagery alone. The improvement is especially notable in separating urban impervious surface from the vacant land/bare ground, which has been a difficult task in ISP modelling with optical remote sensing data. In addition, the results demonstrate the potential to map urban impervious surface by using InSAR data alone. This allows frequent monitoring of world's cities located in cloud-prone and rainy areas. ?? 2009 Taylor & Francis.

Jiang, L.; Liao, M.; Lin, H.; Yang, L.

2009-01-01

30

Effects of impervious pavements on reducing runoff in an arid urban catchment  

Science.gov (United States)

The progressive urbanization of US arid and semi-arid southwestern territories has transformed undeveloped aridlands into dynamic, radially expanding metropolitan centers. As these mature, infill development further reduces undeveloped area, inversely coupling surface imperviousness to infiltration rates, with a subsequent increase in runoff generation. Intensified runoff carries undesirable environmental consequences, magnifying urban flooding events and concentrations, transport, and propagation of contaminants. Pervious pavements offer one potential solution for decreased urban infiltration. At present, the application potential of pervious pavements as an effective urban infiltration management tool exceeds its exploitation. While entirely eliminating urban Total Impervious Area is not a feasible solution, pervious pavements significantly reduce Effective Impervious Area at costs competitive with traditional Best Management Practices. Previous research into pervious pavements has largely consisted of laboratory prototypes or small-scale field experiments, with a heavy bias towards parking lots. In this study we explore the effectiveness of pervious pavements in increasing infiltration, thus decreasing runoff volume during summer monsoonal and winter convective rainfall events in an 8 ha residential catchment in Scottsdale, Arizona. Analysis focuses on the interaction dynamics between surface area of pervious pavement application and its net effect on runoff response at the catchment level. Hydrological response was modeled using MAHLERAN (Model for Assessing Hillslope-Landscape Erosion, Runoff and Nutrients), a spatially explicit, event-based model, parameterized at a spatial resolution of 0.25 sq m. Data for model parameterization was obtained from analysis of aerial imagery and field-based monitoring of surface properties. The model was tested against measurements of flow at the catchment outlet for multiple rainfall events with total event rainfall ranging from 5 mm to 25 mm. Model testing shows total event discharge simulated well, although low Nash-Sutcliffe coefficients for events indicate a poor fit between the shape and timing of the modeled and monitored hydrograph, which we attribute to poor characterization of friction factors in urban catchments. Scenario-based model analysis tested catchment response to substitution of pervious for conventional pavement by percent and pavement-function scenarios. Results are consistent with previous findings in that short duration-high intensity storms trigger threshold infiltration capacity, past which pervious pavement damping of runoff volume levels off, approaching conventional levels. However at the modeled catchment scale, this initial damping represents a significant reduction in volume, peak flow velocity, and contaminant loading potential. Urban surface drainage networks concentrate and channel flow along roads: the capacity of pervious pavements to simultaneously increase infiltration directly at location of greatest runoff and mitigate inflow effects from remote points has compelling potential as a hydrologic and urban systems engineering tool.

Epshtein, O.; Turnbull, L.; Earl, S.

2011-12-01

31

Soil  

International Nuclear Information System (INIS)

Environmental soil surveys in each province of Austria have been performed, soils of about 5,000 sites were described and analyzed for nutrients and pollutants, the majority of these data are recorded in the soil information system of Austria (BORIS) soil database, http://www.ubavie.gv.at/umweltsituation/boden/boris), which also contains a soil map of Austria, data from 30 specific investigations mainly in areas with industry and results from the Austria - wide cesium investigation. With respect to the environmental state of soils a short discussion is given, including two geographical charts, one showing which sites have soil data (2001) and the other the cadmium distribution in top soils according land use (forest, grassland, arable land, others). Information related to the soil erosion, Corine land cover (Europe-wide land cover database), evaluation of pollutants in soils (reference values of As, Cd, Co, Cr, Cu, Hg, Mo, Ni, Se, Pb, Tl, Va, Zn, AOX, PAH, PCB, PCDD/pcdf, dioxin), and relevant Austrian and European standards and regulations is provided. Figs. 2, Tables 4. (nevyjel)

2002-01-01

32

Soil structural behaviour of flooded soils  

International Nuclear Information System (INIS)

The objectives of this presentation are to: identify factors determining of the structural behaviour of flooded soils, as compared to those acting in upland soils; analyse the influence of reductive processes on aggregate stabilising agents; discuss mechanisms of structural deterioration and recovery during the flooding-drying cycle, on the basis of a case study: cattle trampling effects in the flooding Pampa of Argentina. Flooded soils, now known as Hydric soils, are characteristic of wetlands and irrigated fields cropped to rice (paddy soils). In them, water covers the soil, or is present either at or near the surface of the soil all year or for varying periods of time during the year. Hydric soils belong to different taxa of the FAO-UNESCO Soil Map (2000). Fluvisols, Planosols and Gleysols are widespread distributed in the globe. The generation of redoximorphic features is due to different causes in each of them. Fluvisols are covered part of the year by surface water from river overflows; Planosols are soils having an impervious Bt horizon, supporting perched water during short periods; and Gleysols are soils affected by stagnant water tables during long periods

2004-05-01

33

Assessing the impact of urbanization on storm runoff in a peri-urban catchment using historical change in impervious cover  

Science.gov (United States)

This paper investigates changes in storm runoff resulting from the transformation of previously rural landscapes into peri-urban areas. Two adjacent catchments (?5 km2) located within the town of Swindon in the United Kingdom were monitored during 2011 and 2012 providing continuous records of rainfall, runoff and actual evaporation. One catchment is highly urbanized and the other is a recently developed peri-urban area containing two distinct areas of drainage: one with mixed natural and storm drainage pathways, the other entirely storm drainage. Comparison of observed storm hydrographs showed that the degree of area serviced by storm drainage was a stronger determinant of storm runoff response than either impervious area or development type and that little distinction in hydrological response exists between urban and peri-urban developments of similar impervious cover when no significant hydraulic alteration is present. Historical levels of urbanization and impervious cover were mapped from the 1960s to the 2010s based on digitized historical topographic maps and were combined with a hydrological model to enable backcasting of the present day storm runoff response to that of the catchments in their earlier states. Results from the peri-urban catchment showed an increase in impervious cover from 11% in the 1960s to 44% in 2010s, and introduction of a large-scale storm drainage system in the early 2000s, was accompanied by a 50% reduction in the Muskingum routing parameter k, reducing the characteristic flood duration by over 50% while increasing peak flow by over 400%. Comparisons with changes in storm runoff response in the more urban area suggest that the relative increase in peak flows and reduction in flood duration and response time of a catchment is greatest at low levels of urbanization and that the introduction of storm water conveyance systems significantly increases the flashiness of storm runoff above that attributed to impervious area alone. This study demonstrates that careful consideration is required when using impervious cover data within hydrological models and when designing flood mitigation measures, particularly in peri-urban areas where a widespread loss in pervious surfaces and alteration of drainage pathways can significantly alter the storm runoff response. Recommendations include utilizing more refined urban land use typologies that can better represent physical alteration of hydrological pathways.

Miller, James D.; Kim, Hyeonjun; Kjeldsen, Thomas R.; Packman, John; Grebby, Stephen; Dearden, Rachel

2014-07-01

34

A sub-pixel analysis of urbanization effect on land surface temperature and its interplay with impervious surface and vegetation coverage in Indianapolis, United States  

Science.gov (United States)

This study developed an analytical procedure based upon a spectral unmixing model for characterizing and quantifying urban landscape changes in Indianapolis, Indiana, the United States, and for examining the environmental impact of such changes on land surface temperatures (LST). Three dates of Landsat TM/ETM+ images, acquired in 1991, 1995, and 2000, respectively, were utilized to document the historical morphological changes in impervious surface and vegetation coverage and to analyze the relationship between these changes and those occurred in LST. Three fraction endmembers, i.e., impervious surface, green vegetation, and shade, were derived with an unconstrained least-squares solution. A hybrid classification procedure, which combined maximum-likelihood and decision-tree algorithms, was developed to classify the fraction images into land use and land cover classes. Correlation analyses were conducted to investigate the changing relationships of LST with impervious surface and vegetation coverage. Results indicate that multi-temporal fraction images were effective for quantifying the dynamics of urban morphology and for deriving a reliable measurement of environmental variables such as vegetation abundance and impervious surface coverage. Urbanization created an evolved inverse relationship between impervious and vegetation coverage, and brought about new LST patterns because of LST's correlations with both impervious and vegetation coverage. Further researches should be directed to refine spectral mixture modeling by stratification, and by the use of multiple endmembers and hyperspectral imagery.

Weng, Qihao; Lu, Dengsheng

2008-02-01

35

Soil  

…multiple uses to which we put it. We will promote schemes and implement strategies that bring about better soil management and more sustainable agricultural practices. We will help local authorities to identify and improve contaminated land sites, securing the necessary funding and managing the improvement…

36

Soil  

…the improvement programmes. We will enforce permits that remove 50% of acid rain pollutants from power stations, to bring a reduction in soil acidification. We will work closely with local planning authorities and developers so that our views are reflected in development strategies and planning decisions…

37

Soils  

…runoff * Identifying problems with soil structure in the field * General principles to avoid erosion and runoff We deliver thinksoils through training courses and workshops. If you want to find out about training in your area, or have a question about thinksoils, call us on 0370 8506506. To order a copy visit…

38

External geo-information in the segmentation of VHR imagery improves the detection of imperviousness in urban neighborhoods  

Science.gov (United States)

Object-based image analysis (OBIA) has become an established way to detect imperviousness and other land cover classes from very high resolution (VHR) multispectral imagery. Data fusion with LiDAR derived digital surface models (DSM) and large scale vectorial datasets containing building footprints and road boundaries have the potential to significantly improve this method. However, the individual contribution of the large scale vectorial dataset remains unclear. In this paper, we studied the improvement of segmentation and classification results when including a vectorial dataset in the OBIA. Two slightly different segmentation methods making use of the vectorial dataset (boundary suggestion method and absolute boundary method) are compared with each other, with a per-pixel classification of the image and an OBIA segmentation without the input of a vectorial dataset. The performance of all four segmentation methods was assessed both for per-pixel image classification and for segmentation accuracy. The classification accuracy was highest for the segmentation method where the vectorial boundaries were absolute (overall accuracy 82%). However, the boundary suggestion method, where segments were smaller than the reference polygons, had the highest segmentation quality. Although differences between the two methods were clear, the differences with the results of the object-based analysis which did not use the vectorial dataset, were even larger. This indicates that the explicit inclusion of a large scale vectorial dataset is beneficial for the segmentation and classification of imperviousness in an urban environment.

Verbeeck, Klaartje; Hermy, Martin; Van Orshoven, Jos

2012-08-01

39

Quantification of Impervious Surfaces Along the Wasatch Front, Utah: AN Object-Based Image Analysis Approach to Identifying AN Indicator for Wetland Stress  

Science.gov (United States)

The Remote Sensing/GIS Laboratory at Utah State University, in cooperation with the United States Environmental Protection Agency, is quantifying impervious surfaces for three watershed sub-basins in Utah. The primary objective of developing watershed-scale quantifications of impervious surfaces is to provide an indicator of potential impacts to wetlands that occur within the Wasatch Front and along the Great Salt Lake. A geospatial layer of impervious surfaces can assist state agencies involved with Utah's Wetlands Program Plan (WPP) in understanding the impacts of impervious surfaces on wetlands, as well as support them in carrying out goals and actions identified in the WPP. The three watershed sub-basins, Lower Bear-Malad, Lower Weber, and Jordan, span the highly urbanized Wasatch Front and are consistent with focal areas in need of wetland monitoring and assessment as identified in Utah's WPP. Geospatial layers of impervious surface currently exist in the form of national and regional land cover datasets; however, these datasets are too coarse to be utilized in fine-scale analyses. In addition, the pixel-based image processing techniques used to develop these coarse datasets have proven insufficient in smaller scale or detailed studies, particularly when applied to high-resolution satellite imagery or aerial photography. Therefore, object-based image analysis techniques are being implemented to develop the geospatial layer of impervious surfaces. Object-based image analysis techniques employ a combination of both geospatial and image processing methods to extract meaningful information from high-resolution imagery. Spectral, spatial, textural, and contextual information is used to group pixels into image objects and then subsequently used to develop rule sets for image classification. eCognition, an object-based image analysis software program, is being utilized in conjunction with one-meter resolution National Agriculture Imagery Program (NAIP) aerial photography from 2011.

Leydsman-McGinty, E. I.; Ramsey, R. D.; McGinty, C.

2013-12-01

40

Mapping Impervious Surface Expansion using Medium-resolution Satellite Image Time Series: A Case Study in the Yangtze River Delta, China  

Science.gov (United States)

Cities have been expanding rapidly worldwide, especially over the past few decades. Mapping the dynamic expansion of impervious surface in both space and time is essential for an improved understanding of the urbanization process, land-cover and land-use change, and their impacts on the environment. Landsat and other medium-resolution satellites provide the necessary spatial details and temporal frequency for mapping impervious surface expansion over the past four decades. Since the US Geological Survey opened the historical record of the Landsat image archive for free access in 2008, the decades-old bottleneck of data limitation has gone. Remote-sensing scientists are now rich with data, and the challenge is how to make best use of this precious resource. In this article, we develop an efficient algorithm to map the continuous expansion of impervious surface using a time series of four decades of medium-resolution satellite images. The algorithm is based on a supervised classification of the time-series image stack using a decision tree. Each imerpervious class represents urbanization starting in a different image. The algorithm also allows us to remove inconsistent training samples because impervious expansion is not reversible during the study period. The objective is to extract a time series of complete and consistent impervious surface maps from a corresponding times series of images collected from multiple sensors, and with a minimal amount of image preprocessing effort. The approach was tested in the lower Yangtze River Delta region, one of the fastest urban growth areas in China. Results from nearly four decades of medium-resolution satellite data from the Landsat Multispectral Scanner (MSS), Thematic Mapper (TM), Enhanced Thematic Mapper plus (ETM+) and China-Brazil Earth Resources Satellite (CBERS) show a consistent urbanization process that is consistent with economic development plans and policies. The time-series impervious spatial extent maps derived from this study agree well with an existing urban extent polygon data set that was previously developed independently. The overall mapping accuracy was estimated at about 92.5% with 3% commission error and 12% omission error for the impervious type from all images regardless of image quality and initial spatial resolution.

Gao, Feng; DeColstoun, Eric Brown; Ma, Ronghua; Weng, Qihao; Masek, Jeffrey G.; Chen, Jin; Pan, Yaozhong; Song, Conghe

2012-01-01

 
 
 
 
41

Study of the Permeability of Foam Conditioned Soils with Laboratory Tests  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Problem statement: EPB tunneling requires that the excavated soil has a plastic and pulpy behavior to be able to apply a stabilizing pressure to the face, but it should also be impervious to counteract filtration forces that could develop ahead of the face. The evaluation of this parameter in granular soil, before and after conditioning, is therefore of key importance for a correct conditioning agents choice. Approach: A new laboratory procedure for testing the permeability of c...

Luca Borio; Daniele Peila

2010-01-01

42

Soil consolidation method  

Energy Technology Data Exchange (ETDEWEB)

A consolidation composition and method of its use are described. The composition consists of an aqueous alkali metal silicate and a gelling agent. The composition has a viscosity sufficiently low (about one or 2 cps) so that it can penetrate to a predetermined depth in a friable sandstone substrate to consolidate the substrate. The concentration of the silicate is sufficient to be gelled by the gelling agent after penetration into the substrate. The alkali metal silicate has a silica to alkali metal oxide weight ratio of from 2.3:1 to 3.4:1. The gelling agent consists of a tripartite blend of the mono-, di-, and tri-acetate acid esters of glycerol having a saponification value of 590 to 670 mg KOH/g. The viscosity is about one or 2 cps for at least 20 min, whereafter the gelling agent gels the alkali-metal silicate to form a water-impervious soil-consolidating gel. (7 claims)

Pearson, L.L.

1978-02-07

43

Construction works of large scale impervious wall in construction of No.2 plant in Onagawa Nuclear Power Station, Tohoku Electric Power Co., Inc  

International Nuclear Information System (INIS)

The main buildings for No. 2 plant in Onagawa Nuclear Power Station are constructed on the bedrocks about 14 m below the sea surface. Therefore, for the purpose of executing the works by shutting seawater off and dry work, the large scale impervious wall of about 500 m extension was installed underground. The feature of this impervious wall is the depth of embedment of about 3 m into the hard bedrocks having the uniaxial compressive strength of 2000 kg/cm2 at maximum, carried out with the newly developed hard rock excavator. The outline of these construction works is reported. No. 2 plant in Onagawa Nuclear Power Station is the BWR plant of 825 MWe output. The construction works of the power station were began in August, 1989, and the rate of progress in civil engineering works as of the end of September, 1990 was 21.3%. The planning of the impervious wall, the geological features at the site, the method of shutting seawater off, the selection of wall materials, the design of the wall body, the investigation of the quantity of spring water, the execution of the construction and execution management, and the confirmation of the effect of the wall are reported. (K.I.)

1991-01-01

44

Land-Cover and Imperviousness Data for Regional Areas near Denver, Colorado; Dallas-Fort Worth, Texas; and Milwaukee-Green Bay, Wisconsin - 2001  

Science.gov (United States)

This report describes the processing and results of land-cover and impervious surface derivation for parts of three metropolitan areas being studied as part of the U.S. Geological Survey's (USGS) National Water-Quality Assessment (NAWQA) Program Effects of Urbanization on Stream Ecosystems (EUSE). The data were derived primarily from Landsat-7 Enhanced Thematic Mapper Plus (ETM+) satellite imagery from the period 1999-2002, and are provided as 30-meter resolution raster datasets. Data were produced to a standard consistent with data being produced as part of the USGS National Land Cover Database 2001 (NLCD01) Program, and were derived in cooperation with, and assistance from, NLCD01 personnel. The data were intended as surrogates for NLCD01 data because of the EUSE Program's time-critical need for updated land-cover for parts of the United States that would not be available in time from the NLCD01 Program. Six datasets are described in this report: separate land-cover (15-class categorical data) and imperviousness (0-100 percent continuous data) raster datasets for parts of the general Denver, Colorado area (South Platte River Basin), Dallas-Fort Worth, Texas area (Trinity River Basin), and Milwaukee-Green Bay, Wisconsin area (Western Lake Michigan Drainages).

Falcone, James; Pearson, Daniel

2006-01-01

45

Surface and Ground Water Regime in Bi?-field Soils  

Directory of Open Access Journals (Sweden)

Full Text Available The aim of this work was to determine, through several-years stationary investigations, the water regime of soils in the Bi?-field district. Investigations were carried out during a three-year period (2001-2003 on 8,700 ha of agricultural areas. Detailed hydropedological investigations were done in 2000 and a soil map of the district (scale 1:10,000 was produced. Five pedosystematic units were detected: semigley, pseudogleyed, eugley hypogley, eugley amphigley, humogley, and drained soils. Based on three-year continuing monitoring of surface and ground waters the following main types of moistening of the soils were identifi ed: eugley-pseudogley, hypogley, amphigley and drained. Stochastic relation between the Sava and Bi? water levels and groundwater in the agrological profile of studied soils was determined by crosscorrelation with one decade shift s (c = 1. It was found that the ground waters in the profi les of studied soils communicate more intensively with the River Bi? water (r = 0.65-0.69 compared to the River Sava water (r = 0.23-0.69.This especially applies to ground water of hypogley soils, which cover 57% of the studied area. Marked vertical communication of ground water in the deep aquifer with water of the shallow soil aquifer was detected, indicating that the surface layer, mainly made up of silty clayey loams, is not impervious.

Ivan Musta?

2007-03-01

46

Modeling urban heat islands in heterogeneous land surface and its correlation with impervious surface area by using night-time ASTER satellite data in highly urbanizing city, Delhi-India  

Science.gov (United States)

The present study is an assessment and identification of urban heat island (UHI) in the environment of one of the fastest urbanizing city of India, Delhi Metropolis, employing satellite image of ASTER and Landsat 7 ETM+ in the thermal infrared region 3-14 ?m. Temporal (2001 and 2005) ASTER datasets were used to analyze the spatial structure of the thermal urban environment subsequently urban heat island (UHI) in relation to the urban surface characteristics and land use/land cover (LULC). The study involves derivation of parameters governing the surface heat fluxes, constructing statistics of ASTER thermal infrared images along with validation through intensive in situ measurements. The average images reveal spatial and temporal variations of land surface temperature (LST) of night-time and distinct microclimatic patterns. Central Business District (CBD) of Delhi, (Connaught Place, a high density built up area), and commercial/industrial areas display heat islands condition with a temperature greater than 4 °C compared to the suburbs. The small increase in surface temperature at city level is mainly attributed to cumulative impact of human activities, changes in LULC pattern and vegetation density. In this study the methodology takes into account spatially-relative surface temperatures and impervious surface fraction value to measure surface UHI intensity between the urban land cover and rural surroundings. Both the spatial and temporal variation in surface temperature associated with impervious surface area (ISA) has been evaluated to assess the effect of urbanization on the local climate.

Mallick, Javed; Rahman, Atiqur; Singh, Chander Kumar

2013-08-01

47

Soil: Threats  

Sep 1, 2005 ... ... carbon dioxide, particularly as these affect soil ecology and organic matter. ... \\Additionally, rainfall intensity, duration, and amount, could alter soil erosion rates. \\A project investigating the impacts of climate change on soil ...

48

Soil Composition  

Science.gov (United States)

Soil is essential for life on Earth. It is needed for food, air, clothing and so much more. Discussion topics include the terms 'soil', 'dirt', and 'sediment', factors affecting the formation of soils, soil horizons, and the twelve orders of soils. In a hands-on activity, students will collect soil samples from three different locations, use online resources to determine texture and particle makeup, and record their observations.

Fox, Chris; Pratte, John

49

Study of the Permeability of Foam Conditioned Soils with Laboratory Tests  

Directory of Open Access Journals (Sweden)

Full Text Available Problem statement: EPB tunneling requires that the excavated soil has a plastic and pulpy behavior to be able to apply a stabilizing pressure to the face, but it should also be impervious to counteract filtration forces that could develop ahead of the face. The evaluation of this parameter in granular soil, before and after conditioning, is therefore of key importance for a correct conditioning agents choice. Approach: A new laboratory procedure for testing the permeability of conditioned soil with foam has been proposed. The tests have been carried out at different hydraulic loads, chosen to be 0.1 bars and 1 bar. Results: The proposed procedure has been applied to determine the behavior of differently conditioned granular soils: a fluvial sand and a pozzolanic soil and has shown that an increasing of the FIR induces a relative increase in the time required by water to pass through a standard sample, emphasizing, in this way, the effectiveness of the conditioning on impermeability of the soil. Conclusion: The tests have shown the laboratory procedure adequately captures the behavior of the conditioned soil. Further, the proposed test may also be used as an index for the preliminary definition of the quality of the soil conditioning and suitability for EPB tunneling.

Luca Borio

2010-01-01

50

Soil Moisture  

Science.gov (United States)

NOAA's Climate Prediction Center offers this useful data site on soil moisture across the US. Soil moisture data are provided here as color contour maps that represent calculated soil moisture, anomalies, and percentiles for the most recent day, monthly, and twelve-month time periods. Also provided here are 25-year average soil moisture & soil wetness summaries. In addition to providing recent and historical data, the Soil Moisture site features soil moisture forecasts for two-week, monthly, and seasonal intervals, based on the National Weather Service Medium Range Forecast (MRF) and the Constructed Analog on Soil Moisture (CAS).

2000-01-01

51

Extraction and Analysis of Impervious Surfaces Based on a Spectral Un-Mixing Method Using Pearl River Delta of China Landsat TM/ETM+ Imagery from 1998 to 2008  

Directory of Open Access Journals (Sweden)

Full Text Available Impervious surface area (ISA is considered as an indicator of environment change and is regarded as an important input parameter for hydrological cycle simulation, water management and area pollution assessment. The Pearl River Delta (PRD, the 3rd most important economic district of China, is chosen in this paper to extract the ISA information based on Landsat images of 1998, 2003 and 2008 by using a linear spectral un-mixing method and to monitor impervious surface change by analyzing the multi-temporal Landsat-derived fractional impervious surface. Results of this study were as follows: (1 the area of ISA in the PRD increased 79.09% from 1998 to 2003 and 26.88% from 2003 to 2008 separately; (2 the spatial distribution of ISA was described according to the 1998/2003 percentage respectively. Most of middle and high percentage ISA was located in northwestern and southeastern of the whole delta, and middle percentage ISA was mainly located in the city interior, high percentage ISA was mainly located in the suburban around the city accordingly; (3 the expanding direction and trend of high percentage ISA was discussed in order to understand the change of urban in this delta; High percentage ISA moved from inner city to edge of urban area during 1998–2003 and moved to the suburban area that far from the urban area mixed with jumpily and gradually during 2003–2008. According to the discussion of high percentage ISA spatial expanded direction, it could be found out that high percentage ISA moved outward from the centre line of Pearl River of the whole delta while a high ISA percentage in both shores of the Pearl River Estuary moved toward the Pearl River; (4 combining the change of ISA with social conditions, the driving relationship was analyzed in detail. It was evident that ISA percentage change had a deep relationship with the economic development of this region in the past ten years. Contemporaneous major sport events (16th Asia Games of Guangzhou, 26th Summer Universidad of Shenzhen and the government policies also promoted the development of the ISA. Meanwhile, topographical features like the National Nature Reserve of China restricted and affected the expansion of the ISA. Above all, this paper attempted to extract ISA in a major region of the PRD; the temporal and spatial analyses to PRD ISA demonstrated the drastic changes in developed areas of China. These results were important and valuable for land use management, ecological protection and policy establishment.

Renrong Chen

2012-02-01

52

Groundwater Dynamics in Drained Soils of the Bi?-fi eld District  

Directory of Open Access Journals (Sweden)

Full Text Available The main goal of five-year stationary investigations (2001-2006 was to assess groundwater dynamics in the Bi?-field district, as well as the type of soil moistening of agricultural soils spreading over 5838 ha. Detailed hydropedological investigations were carried out in 2000 and a soil map of the region was produced (scale = 1:10000 using universal kriging. Soil investigations identified six pedosystematic units: alluvial-gley, semigley-pseudogley, eugley hypogley, humogley, eugley amphigley and drained soils. Based on permanent monitoring of piezometer groundwater (piezometer depth up to 4.0 m in the period from 2001 to 2006, the following major soil moistening types and subtypes of the separated soil units were determined: semigley-pseudogely, hypogley, humogley, amphigley and drained. Using the correlation method, more intensive groundwater communication was determined in the studied soil profiles with the River Bi? water (r = 0.65-0.69 than with the River Sava water (r = 0.23-0.69, notably in hypogley soils, which cover 54.3% of the studied area. Analysis of the obtained piezometer water level curves indicated a very strong mutual correlation between the groundwater level dynamics in monitored hydrogeological piezometers of 9 m depth (r = 0.87-0.98, as well as a strong correlation (r = 0.75-0.94 between hydrogeological and hydropedological piezometers of 4 m depth. A particularly strong correlation (r = 0.85-0.94 was recorded between hydrogeological and hydropedological piezometers installed in hypogley soil. These data confirm marked vertical communication of groundwater in the deep aquifer with water of the shallow soil aquifer, indicating that the surface layer of the studied area, mainly made up of silty clay loams to silty clays, is not impervious.

Ivan Musta?

2011-03-01

53

Overland flow generation on deep soils in Ethiopia (Lake Tana basin): role of soil texture and plough pan  

Science.gov (United States)

Different applications of rainfall/runoff models in Lake Tana basin (Ethiopia) tend to show that on hill slopes there are vast areas that yield a high runoff response and that behave as if the soil would be nearly impervious (up to 20 % of the hilly catchments). This is well beyond the area occupied by rock outcrops. Duricrusts or hardpans of pedogenetic origin are absent in this environment on basaltic rock with mild tropical climate: no silcretes, calcretes or even ferricretes are known to occur in the basin. Field observations show that runoff response from tilled farmlands can however be unexpectedly high, even when deep theoretically well drained Nitisols occur. In the rainy season, rills and ephemeral gullies are created and these often expose a rock-hard plough pan at some 15 cm depth. Due to repeated tillage at constant depth, the downward pressure of the tip of the ox-drawn ard plough compacts the soil aggregates that are located just below the tilled horizon. In this poster we will discuss the need to not only evaluate the effect of soil texture when interpreting rainfall-runoff relations, but also to investigate the structural and hydrological characteristics of such plough pans.

Nyssen, Jan; Dessie, Mekete; Monsieurs, Elise; Poesen, Jean; Admasu, Teshager; Verhoest, Niko; Adgo, Enyew; Deckers, Jozef

2014-05-01

54

(Contaminated soil)  

Energy Technology Data Exchange (ETDEWEB)

The traveler attended the Third International Conference on Contaminated Soil, held in Karlsruhe, Germany. The Conference was a status conference for worldwide research and practice in contaminated soil assessment and environmental restoration, with more than 1500 attendees representing over 26 countries. The traveler made an oral presentation and presented a poster. At the Federal Institute for Water, Soil and Air Hygiene, the traveler met with Dr. Z. Filip, Director and Professor, and Dr. R. Smed-Hildmann, Research Scientist. Detailed discussions were held regarding the results and conclusions of a collaborative experiment concerning humic substance formation in waste-amended soils.

Siegrist, R.L.

1991-01-08

55

Clay slurry and engineered soils as containment technologies for remediation of contaminated sites  

Energy Technology Data Exchange (ETDEWEB)

Clay Slurry and Engineered Soils are containment technologies for remediation of waste disposal sites where leaching, groundwater plumes and surface runoff of contaminants are serious ecological hazards to adjacent environments. This technology is a patent-pending process which involves the use of conditioned clay materials mixed with sand and water to form a readily pourable suspension, a clay slurry, which is either placed into a trench barrier system or allowed to de-water to create Engineered Soils. The Engineered Soil forms a layer impervious to water and air, therefore by inhibiting both water and oxygen from penetrating through the soil the material. This material can be installed in layers and as a vertical barrier to create a surface barrier containment system. The clay percentage in the clay slurry and Engineered Soils varies depending on site characteristics and desired performance standards. For example Engineered Soils with 1-2% of clay (dry wt.) had a hydraulic conductivity (K) of 10{sup -8} to 10{sup -1} cm/sec. Tests of tailing materials from a kyanite and pyrite mine showed that the clay slurry was effective not only in reducing the permeability of the treated tailings, but also in decreasing their acidity due to the inherent alkalinity of the clay. The untreated tailings had pH values in the range of 2.4 - 3.1; whereas, the effluent from clay and tailings mixtures had pH values in a slightly alkaline range (7.7-7.9). Pug-mills and high volume slurry pumps can be readily adapted for use in constructing and placing caps and creating Engineered Soils. Moreover, material on site or from a local sand supply can be used to create clay slurries and engineered soils. Clay materials used in cap construction are likewise readily available commercially. As a result, the clay slurry system is very cost effective compared to other capping systems, including the commonly used High Density Polyethylene (HDPE) liner systems.

Williams, J.R. [Reclamation Technology, Inc., Athens, GA (United States); Dudka, S.; Miller, W.P. [Univ. of Georgia, Athens, GA (United States); Johnson, D.O. [Argonne National Lab., IL (United States)

1997-12-31

56

Physical properties as indicators of oil penetration in soils, contaminated with oil lakes in the Greater Burgan oil fields, Kuwait  

International Nuclear Information System (INIS)

Measurements were made on 60 samples to determine the physical properties of the soil profiles contaminated with oil lakes in Al-Ahmadi and Burgan oil fields which include 80% of the Greater Burgan oil wells in southern Kuwait. The two soil profiles have similar saturation percentages, field capacities, wilting coefficients, low available water capacities due to statificiation and very low matric potential, and high bulk densities due to compaction by vehicle wheels. The fluviatile origin, relatively poor sorting and unstable structure of the Burgan soil layers have led to lower hydraulic conductivity and permeability, thereby restricting oil penetration mainly to the upper 25-45 cm layer. In contrast, the eolian origin, excellent sorting and stable structure of Al-Ahmadi soil layers have resulted in higher hydraulic conductivity and permeability, and hence allowed the spreading of oil over much greater depths (down to 150 cm). The very low values of the hydraulic conductivities and available water capacities of the zone(s) lying below the impervious Gatch (caliche) layer in the two soil profiles suggest that this layer could act as a moisture barrier impeding any further downward oil penetration. 16 refs., 3 figs., 4 tabs

1998-02-01

57

The monitoring of contaminated impervious planar surfaces  

International Nuclear Information System (INIS)

The responses of several types of surface contamination monitor have been investigated for three typical working surfaces contaminated by three radionuclides commonly used in diagnostic or analytical biomedical applications. Of the three radionuclides, 99mTc is an intermediate-energy gamma emitter, 125I decays by electron capture, emitting low-energy x-rays, and 32P is a moderate-energy beta emitter. For each radionuclide monitored values have generally been found to be within 30% of projected response, this being based on calibrations which make use of standard radionuclide sources and conditions. The several types of contaminated non-absorbent surface that have been investigated produce monitored values which for a given type of monitor and radionuclide cannot be differentiated from each other. (author)

1999-03-01

58

Estimation of impervious-area washoff parameters.  

Science.gov (United States)

In recent years many models have been developed which simulate the quality of rainfall runoff from urban areas. Common to many of these models is the use of an exponential washoff equation. Application of these techniques to a small urban watershed in S Florida demonstrated considerable variability in the optimized parameter values among different storms and among different constituents. -from Author

Alley, W. M.

1981-01-01

59

Soil Association  

Science.gov (United States)

Since its inception over a half century ago, the Soil Association has "been working to raise awareness about the positive health and environmental benefits of organic food and farming and supporting farmers in producing natural food consumers can trust." Originally formed by a coalition of inspired scientists, nutritionists, and farmers, the Soil Association is now the leading organic farming and food certification and campaigning organization in the United Kingdom. Although primarily geared towards citizens of the United Kingdom, the Association website merits a perusal from anyone interested in the organic food movement. Site features include a large online library containing hundreds of documents listed under such categories as Animal Welfare, Biodiversity, Horticulture, Pesticides, and Education; profiles of many organic farms in the UK; a classified ads page with information about employment opportunities and items for sale; information about the Soil Association's standards for organic production and processing; and more.

60

Soil shrinkage characteristics in swelling soils  

International Nuclear Information System (INIS)

The objectives of this presentation are to understand soil swelling and shrinkage mechanisms, and the development of desiccation cracks, to distinguish between soils having different magnitude of swelling, as well as the consequences on soil structural behaviour, to know methods to characterize soil swell/shrink potential and to construct soil shrinkage curves, and derive shrinkage indices, as well to apply them to assess soil management effects

2004-05-01

 
 
 
 
61

Soil-Net.com  

Science.gov (United States)

Soil-Net.com provides teachers and students ages 5 through 16 (UK Key Stages 1-4) with extensive curriculum-based information about soil, one of our three major natural resources alongside air and water. The site helps users learn about what soil is, the teeming life in soil, the many environmental threats facing soils, and current developments affecting soils-related policymaking and soil science. Soil-Net.com was developed by the National Soil Resources Institute (NSRI) of Cranfield University, UK, the leading institution of soil science and soil-related research in England and Wales.

62

Soil consolidation  

Energy Technology Data Exchange (ETDEWEB)

Loose or porous soil is consolidated by gelling in it an aqueous solution of an alkali metal silicate, preferably sodium silicate. The gelling agent is a water-miscible blend of acetic acid esters of glycerol, most preferably one having a defined saponification value falling within the range of 503 to 580 mg KOH/g.

Pearson, L.L.; Plaisted, A.C.

1975-02-11

63

Laboratory Assessment of Water Flow Simulator for Porous Parking Lots Reservoir and Soil Layers  

Directory of Open Access Journals (Sweden)

Full Text Available Porous parking lots were implemented to fill the scarcity and strengthen the sustainable development of impervious surfaces in Malaysia to reduce surface runoff. The new methodology proposed enable simulation of reservoir course at stipulated air voids despite details study on water levels and infiltration of porous parking lots system. A uniformly graded choker and reservoir stones functioned as reservoir structure for temporary storm water detention. A specially fabricated water flow simulator allows laboratory simulation of the porous parking lot system. The ability to simulate 1.24 to 59.89 cm h-1 rainfall intensities enable laboratory testing to verify water level and discharge time correlations with different soil infiltration rate at various rainfall intensities. The laboratory tests of vertical infiltration were conducted under conditions of saturated soils. At 59.89 cm h-1 simulated rainfall intensity, the highest water level recorded inside the water flow simulators body without reservoir course is 55 cm from the surface of 0.254 cm h-1 soil infiltration rate. A total of 80.5 h duration was required to completely discharge the stored water between large aggregate particles due to low soil infiltration rate. Utilizing the same laterite soil as bottom layer, the depth increased by approximately 60% after installation of reservoir course with approximately 40% air voids. Over a 60 min duration, the soil with coefficient of permeability equaled to 25.4 cm h-1 had recorded water level 20 cm in height and completely dried within 32.2 min only.

Zul Fahmi Mohamed Jaafar

2011-01-01

64

Soil fertility management: Impacts on soil macrofauna, soil aggregation and soil organic matter allocation.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Maintenance of soil organic matter through integrated soil fertility management is important for soil quality and agricultural productivity, and for the persistence of soil faunal diversity and biomass. Little is known about the interactive effects of soil fertility management and soil macrofauna diversity on soil aggregation and SOM dynamics in tropical arable cropping systems. A study was conducted in a long-term trial at Kabete, Central Kenya, to investigate the effects of organic inputs (...

Ayuke, F. O.; Brussaard, L.; Vanlauwe, B.; Six, J.; Lelei, D. K.; Kibunja, C. N.; Pulleman, M. M.

2011-01-01

65

Soils; 1 : 500 000  

International Nuclear Information System (INIS)

Soil associations forming map units express representation of soil units in the territory of Slovakia. They present the dominance of the soil units in associations and some other elements, above all the soil-forming substrates and in abbreviated classification also the extreme soil textures (light to heavy). Genetically related units are classified into groups of soil associations. The map was made by generalisation of cartographic materials of all soil investigations and mapping made since 1960 to the present day. (authors)

2002-01-01

66

Soils - Part 3: Soil Organic Matter  

Science.gov (United States)

In this lesson, you will learn such terms as organic, soil organic matter, nutrient, decomposition, humus, compost, and soil structure. In addition, you will be able to predict the effect of land uses on soil organic matter including the effects of different types of vegetation.[This lesson, as well as the other nine lessons in the Soils series, is taken from the "Soils Home Study Course," published in 1999 by the University of Nebraska Cooperative Extension.

67

Soil Stabilization Using Lime  

Directory of Open Access Journals (Sweden)

Full Text Available Soil stabilization can be explained as the alteration of the soil properties by chemical or physical means in order to enhance the engineering quality of the soil . The main objectives of the soil stabilization is to increase the bearing capacity of the soil ,its resistance to weathering process and soil permeability. The long-term performance of any construction project depends on the soundness of the underlying soils. Unstable soils can create significant problems for pavements or structures, Therefore soil stabilization techniques are necessary to ensure the good stability of soil so that it can successfully sustain the load of the superstructure especially in case of soil which are highly active, also it saves a lot of time and millions of money when compared to the method of cutting out and replacing the unstable soil. This paper deals with the complete analysis of the improvement of soil properties and its stabilization using lime.

ANKIT SINGH NEGI

2013-02-01

68

Soil Core Sampling  

Science.gov (United States)

Students learn about one method used in environmental site assessments. They practice soil sampling by creating soil cores, studying soil profiles and characterizing soil profiles in borehole logs. They use their analysis to make predictions about what is going on in the soil and what it might mean to an engineer developing the area.

Integrated Teaching And Learning Program

69

Injection-based stabilization of pervious soils, concrete and masonry structures using particularly finely dispersed binders ???????????? ??????????? ??????????? ???????, ???????? ? ???????? ??????????? ? ?????????????? ????? ??????? ??????????? ????????  

Directory of Open Access Journals (Sweden)

Full Text Available The authors consider the problem of maintenance of buildings and structures of architectural merit. Expedient resolution of this problem consists in the application of a mineral hydraulic binder that has a particularly fine, gradually and smoothly changing granulometric composition and explicit and steady chemical and mineral composition. The above binder is recovered as a result of the air separation of Portland cement. The above binder comprises Portland clinker, furnace slag, and regulator of hardening and mineral additives of R-X, R-U, and R-F brands. The authors have also analyzed the characteristics of several brands and their physical and mechanical properties. Injection-based stabilization of soils and structures is performed through the application of finely dispersed binders used as water suspensions. The choice of binder brands applicable to concrete and masonry structures that have damages of different nature is based on their granulometric composition. The authors have proven that injections of suspensions are to be made at a low pressure with a view to the filling of the porous space of the medium. The practical data obtained by the authors has proven that impregnation of soils both improves their bearing capacity and converts them into structural elements. Application of finely dispersed binders improves impervious properties of strengthened massifs and their resistance to various aggressive actions, as well as their curing at negative temperatures, rate of strength development, etc.??????????? ???????? ??????? ?????? ? ??????????, ?????????????? ????????????? ????????, ?? ??????? ??????? ???????????????? ?????????? ???????????? ??????????????? ???????? ? ????? ??????, ????????? ? ?????? ???????????? ??????????????????, ? ????? ???????????? ? ?????????? ??????-???????????????? ????????, ??????????? ????? ????????? ????????? ???????????????, ??????? ??????? ?? ?????????????????? ????????, ????????? ?????, ??????????? ????????? ? ??????????? ??????? ????? R-X, R-U, R-F. ???????? ?????????????? ????????? ?????, ?? ??????-???????????? ????????. ?????????? ??????????????? ??????? ??? ????????????? ??????????? ??????? ? ??????????? ?????????????? ? ???? ?????? ?????????. ??? ???????? ? ???????? ??????????? ? ????????? ?????????? ??????????? ????? ????? ???????? ?????? ? ?? ????????? ?????????????????? ????????. ????????, ??? ?????????????? ? ??????????? ????????? ?????????? ??? ?????? ???????? ? ????? ?????????? ???????? ???????????? ?????. ???????? ?????? ? ???, ??? ???????? ??????? ?? ?????? ???????? ?? ??????? ???????????, ?? ? ?????????? ? ?????????????? ???????? ??????????. ????????????? ???????????????? ???????? ????????? ???????? ????????????????????? ???????? ??????????? ????????, ????????? ? ????????? ??????????? ????????????, ????????? ? ???????? ????????????? ???????????, ???????? ?????? ????????? ? ?.?.

Kharchenko Igor Yakovlevich

2012-11-01

70

Does Soil Disturbance Affect Soil Phosphorus Fractions?  

Directory of Open Access Journals (Sweden)

Full Text Available Increased turnover of organic matter as a result of soil disturbance (e.g. by soil tillage is described in principle, but the direct influence of soil disturbance on soil P turnover especially for organic farming systems has not been sufficiently proven. The objective of the study was to evaluate the short term effect of soil disturbance on different soil P fractions in a soil shaking experiment. Four soils were incubated for 10 days in the dark with three different disturbance treatments: 1 no disturbance, 2 overhead shaking for 2 h at the beginning of the experiment and 3 continuous overhead shaking at 5 r. p. m. The four investigated soils were: 1 a silty loam soil with long term bio-compost application and 2 the corresponding soil without bio-compost application, 3 a long-term organically managed clay loam soil and 4 a clay loam soil with long time application of pig manure, all not and from Baden-Württemberg, Germany. We determined NaHCO3-, NaOH- and H2SO4-extractable inorganic and organic P fractions (Pi and Po, resp. in a sequential extraction. Furthermore, the potentially plant available P as Calcium-acetate-lactate-extractable P (CAL-P and P extractable by electro-ultra-filtration (EUF-P, and aqua regia extractable total P (PT were determined. Furthermore, we determined microbial biomass carbon (MBC, nitrogen (MBN and phosphorus (MBP, and acid phosphatase activity in soil. The organically managed soil had the highest PT contents (1300 mg·kg-1. The soil with pig manure application had the smallest potentially labile P fractions (NaHCO3-Pi and -Po and NaOH-Pi. The ecologically managed soil had the biggest organic P fractions (114 mg·kg-1 NaHCO3-Po and 463 mg·kg-1 NaOH-Po, but, this soil was the lowest in CAL-P (5 mg·kg-1. Short term soil disturbance had effects on labile organic P fractions of two of the four analyzed soils, but inorganic P was rather unaffected. In the compost amended COMP(+ soil, there was an incorporation of P from the less available NaOH-P fractions into the more available NaHCO3-Po fraction. However, if taking all investigated soils and treatments into account, the effects of soil disturbance were limited and not consistent.

Yonathan D. Redel

2013-10-01

71

Soil Science Education Website  

Science.gov (United States)

This National Soil Survey Center (NSSC) website provides details about teaching soils in the classroom. There is information for teachers about what soils are, how they form, how they are classified, and what the soil survey does. There are lesson plans and activities on soil erosion, organic matter, soil air, particle sizes, texture, and monoliths. The site offers downloadable poster and PowerPoint presentations, and instructions on how to make a soil testing kit to use with classes. There are also links to K-12 and university soil websites.

72

Trees, Soil and Water  

Science.gov (United States)

Trees, soil and water: Journey to Forever - health care for mountains, trees for deserts, trees for people, forest, forestry, deforestation, erosion, soil conservation, water conservation, desertification.

Addison, Keith

2010-01-01

73

USING AN "IMPERVIOUS PERMIT" ALLOWANCE SYSTEM TO REDUCE IMPERVIOUS SURFACE COVERAGE FOR ENVIRONMENTAL SUSTAINABILITY  

Science.gov (United States)

Current development dynamics and population projections suggest that further decentralized urbanization is likely to proceed into the near future, resulting in the continuing degradation of the physical environment. It is therefore necessary to introduce government...

74

Soils as Construction Materials  

Science.gov (United States)

This geotechnical project will introduce you with the concept of using soils as construction materials.This project involves characterizing soils using various laboratory analyses and applying the Unified Soil Classification System in naming the soil. Keywords: Geotechnical, Mass Wetness, Grain Size Analysis, Atterberg Limits

Kowalewski, Douglas

75

Lunar Soil Particle Separator  

Science.gov (United States)

The Lunar Soil Particle Separator (LSPS) beneficiates soil prior to in situ resource utilization (ISRU). It can improve ISRU oxygen yield by boosting the concentration of ilmenite, or other iron-oxide-bearing materials found in lunar soils, which can substantially reduce hydrogen reduction reactor size, as well as drastically decreasing the power input required for soil heating

Berggren, Mark

2010-01-01

76

Soil physical properties affecting soil erosion in tropical soils  

International Nuclear Information System (INIS)

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 detachment. Studies on necessary kinetic energy to detach one kilogram of sediments by raindrop impact have shown that the minimum energy is required for particles of 0.125 mm. Particles between 0.063 to 0.250 mm are the most vulnerable to detachment. This means that soils with high content of particles into vulnerable range, for example silty loam, loamy, fine sandy, and sandy loam are the most susceptible soils to detachment. Many aspects of soil behaviour in the field such as hydraulic conductivity water retention, soil crusting, soil compaction, and workability are influenced strongly by the primary particles. In tropical soils also a negative relation between structure stability and particles of silt, fine sand and very fine sand has been found, this is attributed to low cohesiveness of these particles. The ability of a structure to persist is known as its stability. There are two principal types of stability: the ability of the soil to retain its structure under the action of water, and the ability of the soil to retain its structure under the action of external mechanical stresses. (e.g. by wheels). Both types of stability are related with susceptibility to erosion

2004-05-01

77

Soil Erosion Studies  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Soil erosion affects a large part of the Earth surface, and accelerated soil erosion is recognized as one of the main soil threats, compromising soil productive and protective functions. The land management in areas affected by soil erosion is a relevant issue for landscape and ecosystems preservation. In this book we collected a series of papers on erosion, not focusing on agronomic implications, but on a variety of other relevant aspects of the erosion phenomena. The book is divided into th...

Godone, Danilo Francesco; Stanchi, Silvia

2011-01-01

78

Soil hydraulic properties of Cuban soils  

International Nuclear Information System (INIS)

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)

2004-05-01

79

Ecology of soil fungi  

Energy Technology Data Exchange (ETDEWEB)

The influence of soil type and soil horizon on the distribution of microfungi in five natural grassland soils at Lakenheath Warren has been investigated. The soils, which are all very dry and sandy, vary from a shallow, highly alkaline soil to a deep, highly acid podsol. One hundred and forty-eight species of fungi have been isolated from these soils by the soil-plate method. The most common genera are penicillium and mortierella, followed by Absidia, Cephalosporium, Fusarium, Gliocladium, Gliomastix, Mucor, Thielavia, Trichoderma, and Zygorrhynchus. The occurrence of fungal species in twenty profile samples of each soil has been recorded, and the distribution of the More important species is discussed in detail. It has been shown that the number of fungal species and colonies in a profile falls off with depth, the rate of reduction being dePendent on the depth of the soil and the nature of the soil horizons. Most species occur most abundantly in the surface layers of the soil. A few species were commoner in subsurface layers, and a few were abundant near the chalky boulder clay of the c horizons. Fungi show different distributions in the five soils, and two large groups may be distinguished. Those common in the acid soils and those common in the alkaline soils. Species of Penicillium were particularly abundant in the acid soils. Microscopic examination of soil has shown that fungi are present both as spores and mycelium. Study of incubated soil plates stained with lactophenol cotton blue has shown that most of the colonies develop from humus particles. Viable spores have also been found in these soils, especially the acid ones.

Warcup, J.H.

1951-01-01

80

Diffusion in soil crumbs  

International Nuclear Information System (INIS)

In a multi-component system matter can move as a result of mass-flow and by diffusion. In soil both means of transport occur, but while mass-flow is largely restricted to the coarse pores between the soil aggregates (crumbs), transport by diffusion prevails inside the soil crumbs where the media in which diffusion occurs (water and air) are held in the fine pores by capillary forces. A similar situation exists in compacted (structureless) soil but as soil with a crumb-structure is the normal and more favourable medium for plant growth, a discussion of diffusion in soil crumbs is desirable

1965-11-01

 
 
 
 
81

Soil washing technology evaluation  

International Nuclear Information System (INIS)

Environmental Restoration Engineering (ERE) continues to review innovative, efficient, and cost effective technologies for SRS soil and/or groundwater remediation. As part of this effort, this technical evaluation provides review and the latest information on the technology for SRS soil remediation. Additional technology evaluation reports will be issued periodically to update these reports. The purpose of this report is to review the soil washing technology and its potential application to SRS soil remediation. To assess whether the Soil Washing technology is a viable option for SRS soil remediation, it is necessary to review the technology/process, technology advantages/limitations, performance, applications, and cost analysis

1995-01-01

82

iSOIL: Interactions between soil related sciences - Linking geophysics, soil science and digital soil mapping  

Science.gov (United States)

High-resolution soil property maps are one major prerequisite for the specific protection of soil functions and restoration of degraded soils as well as sustainable land use, water and environmental management. To generate such maps the combination of digital soil mapping approaches and remote as well as proximal soil sensing techniques is most promising. However, a feasible and reliable combination of these technologies for the investigation of large areas (e.g. catchments and landscapes) and the assessment of soil degradation threats is missing. Furthermore, there is insufficient dissemination of knowledge on digital soil mapping and proximal soil sensing in the scientific community, to relevant authorities as well as prospective users. As one consequence there is inadequate standardization of techniques. At the poster we present the EU collaborative project iSOIL within the 7th framework program of the European Commission. iSOIL focuses on improving fast and reliable mapping methods of soil properties, soil functions and soil degradation risks. This requires the improvement and integration of advanced soil sampling approaches, geophysical and spectroscopic measuring techniques, as well as pedometric and pedophysical approaches. The focus of the iSOIL project is to develop new and to improve existing strategies and innovative methods for generating accurate, high resolution soil property maps. At the same time the developments will reduce costs compared to traditional soil mapping. ISOIL tackles the challenges by the integration of three major components: (i)high resolution, non-destructive geophysical (e.g. Electromagnetic Induction EMI; Ground Penetrating Radar, GPR; magnetics, seismics) and spectroscopic (e.g., Near Surface Infrared, NIR) methods, (ii)Concepts of Digital Soil Mapping (DSM) and pedometrics as well as (iii)optimized soil sampling with respect to profound soil scientific and (geo)statistical strategies. A special focus of iSOIL lies on the sustainable dissemination of technologies and concepts developed in the projects through workshops for stakeholders and the publication of a handbook "Methods and Technologies for Mapping of Soil Properties, Function and Threat Risks". Besides, the CEN Workshop offers a new mechanism and approach to standardization. During the project we decided that the topic of the CEN Workshop should focus on a voluntary standardization of electromagnetic induction measurement to ensure that results can be evaluated and processed under uniform circumstances and can be comparable. At the poster we will also present the idea and the objectives of our CEN Workshop "Best Practice Approach for electromagnetic induction measurements of the near surface"and invite every interested person to participate.

Dietrich, Peter; Werban, Ulrike; Sauer, Uta

2010-05-01

83

Iodine dynamics in soil  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The principal aim of this investigation was to understand the transformation and reaction kinetics of iodide and iodate added to soil in relation to soil properties. In addition, to integrate the data into a predictive model of iodide and iodate sorption kinetics parameterised by soil properties. Solid phase fractionation coupled with solution phase speciation (HPLC-ICPMS) was used to follow the assimilation of 129I- and 129IO3- spikes into ‘steady state’ soil microcosms.

Hassan Shetaya, Waleed Hares Abdou

2011-01-01

84

Soil function and "malfunction"  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Most of the scientists define soil from an “agronomic” point of view as the natural system delegated to sustain plant
growth and agricultural productions on the whole. In this paper soil importance, even in “environmental and social”
terms, is pointed out, considering soil as a natural body with its own functional characteristics, regardless of
its agronomic role and productive ability. Some studies show that soil acts as a thermal buff...

Andrea Buondonno; Elio Coppola

2011-01-01

85

Soil function and "malfunction"  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Most of the scientists define soil from an “agronomic” point of view as the natural system delegated to sustain plantgrowth and agricultural productions on the whole. In this paper soil importance, even in “environmental and social”terms, is pointed out, considering soil as a natural body with its own functional characteristics, regardless ofits agronomic role and productive ability. Some studies show that soil acts as a thermal buffer and detoxifies ...

Andrea Buondonno; Elio Coppola

2008-01-01

86

Soil Biological Communities  

Science.gov (United States)

The Bureau of Land Management (BLM) in Idaho provides this electronic resource on soil communities. With introductory text, illustrations, and references, these pages provide a general overview of soil communities, including Biological Crusts, Fungi, Bacteria, Protozoa, Nematodes, and Arthropods. The site also introduces general readers to Soil Food Webs and Burrowing Mammals, with an emphasis on the western United States. A series of select links to soil-related resources rounds out the site.

2000-01-01

87

Neptunium in soils  

International Nuclear Information System (INIS)

A bibliography and compiled data are presented on neptunium isotopes in different soil types, especially 237Np. After surveying soil chemistry and sorption behaviour of a variety of rock types and soil types like loams, sands and clays, the mobility of neptunium is considered. (G.J.P.)

1984-01-01

88

Soils and runoff  

…at the importance of examining, understanding and improving soil condition to reduce run-off and diffuse pollution from agriculture. When soil is compacted it is unable to absorb all of the rain that falls on it. When water cannot drain into the soil, it ponds on the surface during rainfall, which can…

89

Tropical Soil Chemistry  

DEFF Research Database (Denmark)

A new book that is particularly relevant as tropical countries experience increased pressure on land resources to improve agricultural production. To ensure sustainable land use, the potentials and limitations of different kinds of tropical soils must be known in relation to crop production and environmental protection. Tropical Soil Chemistry by Ole K. Borggaard provides an overview of the composition, occurrence, properties, processes, formation, and environmental vulnerability of various tropical soil types (using American Soil Taxonomy for classification). The processes and the external factors that affect soil processes are the same in tropical soils as in temperate region soils, but because of high temperature year round and occurrence in very stable landscapes, some (but not all) tropical soils possess special composition and properties. These features are highlighted in the book, and general soil chemical issues are also presented to assess when, why, and how tropical soils differ from soils in other regions. This knowledge can help agricultural specialists in the tropics establish sustainable crop production. Readers are assumed to be familiar with basic chemistry, physics, and mathematics at a level corresponding to introductory university courses. Knowledge of fundamental geology, geography, and soil science is also needed. The book can be purchased from the Department.

Borggaard, Ole K.

2008-01-01

90

Gravimetric Soil Moisture Protocols  

Science.gov (United States)

The purpose of this resource is to measure soil water content by mass. Students collect soil samples with a trowel or auger and weigh them, dry them, and then weigh them again. The soil water content is determined by calculating the difference between the wet sample mass and the dry sample mass.

The GLOBE Program, University Corporation for Atmospheric Research (UCAR)

2003-08-01

91

Soil vs. Rocks  

Science.gov (United States)

This lesson will extend the learning on rocks with the Foss kit, Pebbles, Sand, and Silt to include soil. Students will perform the soil sifting activity like the one designed for rocks in the Foss it. Through their work, students will complete a Venn diagram of soil and rocks as a class.

Ama Xiong, Ames Elementary School, Saint Paul, MN Based on an original activity from the FOSS Kit, Pebbles, Sand, & Silt.

92

Bioindication with soil microfauna  

International Nuclear Information System (INIS)

The state of a soil can be characterised through its inhabitant micro-, meso-, and macrofauna. For an appropriate assessment of soil quality at least one representative of each of these size categories should be studied (e.g. testacea, mites, earthworms). This contribution summarizes the insights gained from microscopic soil fauna in this context. The following practical examples are discussed: pesticides, organic and artificial fertilisers, soil compaction, ecological and conventional farming, recolonisation. The 'weighted cenosis index' represents a quantitative measure for the influence of anthropogenic activity on a soil. (orig.)

1991-09-24

93

How Can Soil Electrical Conductivity Measurements Control Soil Pollution?  

Directory of Open Access Journals (Sweden)

Full Text Available Soil pollution results from the build up of contaminants, toxic compounds, radioactive materials, salts, chemicals and cancer-causing agents. The most common soil pollutants are hydrocarbons, heavy metals (cadmium, lead, chromium, copper, zinc, mercury and arsenic, herbicides, pesticides, oils, tars, PCBs and dioxins. Soil Electrical Conductivity (EC is one of the soil physical properties w hich have a good relationship with the other soil characteristics. As measuring soil electrical conductivity is easier, less expensive and faster than other soil properties measurements, using a detector that can do on the go soil EC measurements is a good tool for obtaining useful information about soil pollution condition.

Mohammad Reza

2010-10-01

94

Soil aeration status of some austrian soils  

Directory of Open Access Journals (Sweden)

Full Text Available Observed climatic changes connected with an increase of temperature and a depression of ground water level motivated this joint investigation of Central Europe soils. The purpose of this paper is to characterize the aeration status of two sites representing typical regions for the agricultural production of Lower Austria (Wieselburg and Fuchsenbigl on the basis of results obtained in the frame of the multilateral Austrian-Czech-Hungarian-Polish-Slovak project on 'Assessment of Structure in Agricultural Soils' sponsored by the Austrian Ministry of Science and Research. The paper comprises results of measurements of different soil aeration properties such as: oxygen diffusion rate (ODR, redox potential (Eh, relative gas diffusion coefficient (DD0, air permeability (k and activity of soil dehydrogenase. Undisturbed soil cores were tested in the range of soil moisture tension from 0 hPa (pF 0 to 500 hPa (pF 2.7.Statistical analysis of relationships between tested parameters were performed.

Wimmer B.

1997-09-01

95

Spectromicroscopy of soil colloids  

Science.gov (United States)

A soil with a high organic content, a calcaric phaeozem, has been imaged in a hydrated state using the Stony Brook scanning transmission X-ray microscope at the NSLS, Brookhaven, USA. This experiment has been performed at the carbon K absorption edge to determine the distribution of organic matter within this soil. Spectromicroscopic methods using the known spectra of humics are helping to distinguish between different kinds of carbon in the sample. In addition, a marsh soil from Northern Germany has been analyzed at the sulfur K-absorption edge with the scanning X-ray microscope at the ESRF (ID 21), Grenoble, France. This soil contains a variety of sulfur containing components, which are attached to the soil colloids. A major source of these components is the microbial activity. In this soil it is possible to identify spectroscopically amino acids like methionin and cysteine and proteins, which are built up from those molecules, and inorganic components like sulfates and sulfides.

Schmidt, C.; Thieme, J.; Neuhäusler, U.; Jacobsen, C.; Kaulich, B.; Salomé, M.; Susini, J.

2003-03-01

96

Soils and climate change  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Soils contain vast reserves (similar to 1500 Pg C) of carbon, about twice that found as carbon dioxide in the atmosphere. Historically, soils in managed ecosystems have lost a portion of this carbon (40-90 Pg C) through land use change, some of which has remained in the atmosphere. In terms of climate change, most projections suggest that soils carbon changes driven by future climate change will range from small losses to moderate gains, but these global trends show considerable regional vari...

2012-01-01

97

Soil life under stress  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this thesis I studied how long-term soil contamination affects microbial populations and processes, ecosystem properties and functional stability. I also investigated which parameters are suitable as indicators of soil quality in long-term contaminated soils. I found that contamination had a negative impact on many examined microbial parameters, e.g. biomasses, respiration and growth rate (Chapter 2). Some parameters like protozoan biomass and metabolic quotient did not show any effect of ...

Tobor-kaplon, Maria Agnieszka

2006-01-01

98

Multilingual soil database  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The FAO-ISRIC-CSIC Multilingual Soil Database (SDBm) is a multilingual (English/French/Spanish) system designed to store and manipulate morphological and analytical soil data. It is a collection of programs written in CLIPPER 5.2 and C languages which constitutes a user-friendly tool for an efficient and systematic organization of soil profile data. Data storage is greatly facilitated by the multilingual function which provides "assist menus" in the selected language. Decoding ...

La Rosa, Diego; Mayol Rodri?guez, Francisco; Moreno Arce, Juan A.; Grita, F.

1995-01-01

99

Resistant ultralaminae in soils  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Observation of a chemically resistant organic residue from maize crop soils by transmission electron microscopy reveals the occurrence of thin laminae with 10-50 nm thickness, similar to resistant, highly aliphatic biopolymers found in kerogens and microbes. This discovery shows evidence for a novel and alternative mode of formation of soil organic matter by selective preservation of resistant biopolymers from soil microbes, in addition to the classical recondensation pathway proposed by the ...

Lichtfouse, Eric; Chenu, Claire; Baudin, Franc?ois

1996-01-01

100

The Living Soil  

Science.gov (United States)

Soil is home to vast numbers of organisms, and even small sections of earth teem with a diverse array of life. This Topic in Depth takes a closer look at the world beneath our feet through the lens of soil biologists and ecologists. The first website (1) provides information about the activities of a Natural Environment Research Council-supported research program "on the biological diversity of soil biota and the functional roles played by soil organisms in key ecological processes." The second site (2) contains information about several research projects of the Ecology of Soil Organisms Theme Group at Wageningen University and Research Centre. The Theme Group studies "soil organisms at the population, community, and ecosystem level, to ultimately increase understanding of the role of soil organisms." The third site (3) contains a list of publications spanning the past fifteen years from members of the Soil Ecology Group at the University of Jyv'skyl". The site also provides basic information about group members, and concise descriptions of current research projects. From the USDA Natural Resources Conservation Service, the fourth website (4) contains an online version of the _Soil Biology Primer_, "an introduction to the living component of soil and how it contributes to agricultural productivity, and air and water quality. The Primer includes units describing the soil food web and its relationship to soil health, and units about bacteria, fungi, protozoa, nematodes, arthropods, and earthworms." The online version of the Primer contains the entire text of the original published version, but is missing some useful soil organism images. The fifth site (5) links to sixteen movies relating to different aspects of soil biology such as nematodes, mites, springtails, and protozoa. The movies were all produced by Dr. Thomas E. Loynachan, a Professor of Agronomy and Microbiology at Iowa State University. Finally, Soils Are Alive (6) was developed by Professor Lyn Abbot of the University of Western Australia and Jen Slater, a qualified secondary school science teacher. This website contains informative, concise sections addressing Soil Biology, Biological Processes, Living Components, and Ecosystem Management.

 
 
 
 
101

Microbiological soil regeneration  

International Nuclear Information System (INIS)

The Interdiciplinary Task Force ''Environmental Biotechnology - Soil'' of DECHEMA aims to pool the knowledge potential of the Dechema study committees on environmental biotechnology and soil protection with a view to the advancement of microbiological soil decontamination techniques. This conference volume on the 9th expert meeting of Dechema on environmental protection subjects entitled ''Microbiological Soil Regeneration'', held on February 27th and 28th, 1991, and the subsequent compilation of results give an intermediate account of the ongoing work of the Dechema Task Force. (orig.)

1991-02-27

102

Earthworms and Soil Pollutants  

Directory of Open Access Journals (Sweden)

Full Text Available Although the toxicity of metal contaminated soils has been assessed with various bioassays, more information is needed about the biochemical responses, which may help to elucidate the mechanisms involved in metal toxicity. We previously reported that the earthworm, Eisenia fetida, accumulates cadmium in its seminal vesicles. The bio-accumulative ability of earthworms is well known, and thus the earthworm could be a useful living organism for the bio-monitoring of soil pollution. In this short review, we describe recent studies concerning the relationship between earthworms and soil pollutants, and discuss the possibility of using the earthworm as a bio-monitoring organism for soil pollution.

Kazuyoshi Tamae

2011-11-01

103

Soil nematode communities in grasslands  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This thesis summarizes the results of five studies investigating the effect of plant species on soil nematode communities in grasslands. Nematodes (roundworms) are ubiquitous members of the soil fauna and have been much used as indicators of soil conditions. Plants have the ability to affect soil organisms through structural modification of the soil habitat and through the quantity and quality of organic matter that is returned to soil, in the form of plant litter and root exudates. The influ...

2007-01-01

104

Soil data from Spain. Andalusia  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The EU - HYDI database of Andalusia region was obtained from the SEIS.net database (www.evenor - tech.com) which stores soil information from more than 1000 soil profiles. Soil data harmonization was previously stored and performed with the SDBm Plus (De la Rosa et al., 2002) , component of MicroLEIS DSS. This soil database is a multilingual soil profile database that stores and retrieves geo - referen ced soil attribute data collected in soi...

Anaya Romero, Mari?a

2013-01-01

105

Soil Repair Factsheet  

…we will consider this and the odour potential of the facility as part of our application process. When the soil is being treated it will be under suction, so any odour causing hydrocarbon will be passed through a bio filter with the air stream. For Westmill II landfill, Biffa will assess the soil for…

106

Humus Acids of Soils.  

Science.gov (United States)

Humus acids are known to occur widely in soils, peats, and natural waters. Soil fertility, migration and accumulation of minerals in natural landscapes, and mineral nutrition of plants are all associated with these acids. In recent times they have been us...

D. S. Orlov

1985-01-01

107

The Dirt on Soil  

Science.gov (United States)

The latest from DiscovorySchool.com (last mentioned in the February 22, 2002 NSDL Life Science Report) is the extensive and very well done Web lesson -- the Dirt on Soil. The Down and Dirty portion of the site describes the different layers of soil, how they are formed, what they usually consist of, soil particle size comparisons, and more. The field guide link contains photographs and descriptions of a creature from each major group of soil organisms, such as the creepy looking Beetle Mite. The last link on the main page is for the unbelievably cool Soil Safari interactive Flash activity. After getting into the Earthship, you navigate through different layers of soil to discover what organisms and soils are within. This really is an excellent activity for kids and adults wanting to learn about soil or just have fun. One additional feature of the site is the very helpful teachers tip link that gives summarized descriptions of the site and advice on how best to utilize it.

2002-01-01

108

Electrochemical soil decontamination  

Energy Technology Data Exchange (ETDEWEB)

This article examines an innovative and cost-effective remediation technology that employs conduction phenomena in soils under an electric field to remove chemical species. The transport processes are accompanied by sorption processes in the soil, precipitation and dissolution, and other aqueous phase reactions in the pore fluid stimulated by the electric potential difference between the electrodes.

Billings, C.H.

1994-03-01

109

Creative Soil Conservation  

Science.gov (United States)

Take plant lessons outdoors with this engaging and inquiry-based activity in which third-grade students learn how to apply soil conservation methods to growing plants. They also collect data and draw conclusions about the effectiveness of their method of soil conservation. An added benefit to this activity is that the third-grade students played…

Smith, Martha

2010-01-01

110

The Changing Model of Soil  

Science.gov (United States)

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

Richter, D. D.; Yaalon, D.

2012-12-01

111

Soil invertebrates as bioindicators of urban soil quality  

International Nuclear Information System (INIS)

This study aimed at relating the abundance and diversity of invertebrate communities of urban soils to chemical and physical soil characteristics and to identify the taxa most sensitive or tolerant to soil stressors. The invertebrate community of five urban soils in Naples, Italy, was sampled. To assess soil quality invertebrate community indices (Shannon, Simpson, Menhinick and Pielou indices), Acarina/Collembola ratios, and the soil biological quality index (QBS) were calculated. The chemical and physical characteristics of the soils strongly differed. Abundance rather than taxa richness of invertebrates were more affected by soil characteristics. The community was more abundant and diverse in the soils with high organic matter and water content and low metal (Cu, Pb, Zn) concentrations. The taxa more resistant to the urban environment included Acarina, Enchytraeids, Collembola and Nematoda. Collembolans appeared particularly sensitive to changing soil properties. Among the investigated indices, QBS seems most appropriate for soil quality assessment. - Highlights: ? The abundance and diversity of invertebrate communities was related to properties and metal contents of urban soils. ? Several (biodiversity) indices were calculated and compared to evaluate soil quality. ? Metal contamination affected invertebrate density and diversity. ? The taxa more tolerant to metal contamination were Acarina, Enchytraeids, Collembola and Nematoda. ? The soil biological quality index QBS index was most appropriate for soil quality assessment. - Soil metal contamination negatively affected soil invertebrate abundance and diversity.

2012-02-01

112

Bricks in urban soils  

Science.gov (United States)

Bricks can be considered as anthropogenic markers since they are regularly found in urban soils worldwide. They are known to fulfill soil functions due to their pore system. The purpose of this study is to investigate abundance and functions of bricks in urban soils, focusing on plant nutrition and contamination aspects. Three different Berlin urban soils have been studied for their brick contents in the coarse and fine earth fractions by hand sorting. Light and scanning electron microscopy was then employed to investigate the bricks for rooting. Third, CEC, pH, EC, Corg, nutrient storage (XRF) and availability (2:1 extract, ion chromatography, AAS) of bricks and fine earth fractions of the corresponding soil horizons have been investigated. The fine earth fractions of the investigated soils contain 3 to 5 % of bricks, while the coarse fractions contain up to 50 %. Roots enter brick pores or attach to brick surfaces. Therefore, they can use the water and nutrients stored in bricks. The CEC of bricks is grain size dependent and reaches a maximum of 6 cmolc kg-1 for particles smaller than 0.063 mm. This dependency is not explained by a low pore connectivity. Rather, it is the result of the restricted diffusion into the brick pore system due to the short shaking time in the CEC analysis protocol. From the nutrient storage and availabilities we conclude that bricks can better supply plants with K, Mg, Ca and S than the bulk soil at the investigated site. However, in general, the nutrient availability from bricks is rather low compared to agricultural soils, except for Ca and S. Because of the water and nutrient storage, low contamination status and the possible rooting of bricks, they can be used for amelioration of poor sandy soils and for soil construction.

Nehls, T.; Rokia, S.; Mekiffer, B.; Wessolek, G.

2012-04-01

113

Soil bacteria for remediation of polluted soils  

Energy Technology Data Exchange (ETDEWEB)

Soil bacteria, specifically adapted to contaminated soils, may be used for the remediation of polluted soils. The Flemish research institute VITO has established a collection of bacteria, which were isolated from contaminated areas. This collection includes microbacteria degrading mineral oils (Pseudomonas sp., Acinetobacter sp. and others), microbacteria degrading polycyclic aromatic hydrocarbons (genera Sphingomonas and Mycobacterium), microbacteria degrading polychlorobiphenyls (genus Ralstonia and strains related to beta-Proteobacteria), and metal resistant bacteria with plasmid borne resistances to Cd, Zn, Ni, Co, Cu, Hg, and Cr. Bench-scale reactors were developed to investigate the industrial feasibility of bioremediation. Batch Stirred Tank Reactors were used to evaluate the efficiency of oil degraders. Soils, contaminated with non-ferrous metals, were treated using a Bacterial Metal Slurry Reactor. It was found that the reduction of the Cd concentration may vary strongly from sample to sample: reduction factors vary from 95 to 50%. Is was shown that Cd contained in metallic sinter and biologically unavailable Cd could not be removed.

Springael, D.; Bastiaens, L.; Carpels, M.; Mergaey, M.; Diels, L.

1996-09-18

114

Fixation Status of Acid Soils  

International Nuclear Information System (INIS)

Six acid soil series from different benchmark sites; Rangsit soil (Sulfic Tropaquepts) (two acid sulfate soils), Pakchong soil (Oxic Paleustults) Korat soil (Oxic Paleustults), Warin soil (Oxic Paleustults), Mae Taeng soil (Typic paleustults) and Boundary grey soil and two Thai phosphate rocks (P R) (Lampun P R and Ratchabuie P R) had been characterized in the laboratory by isotope techniques (E, value Part 1). Triple superphosphate (TSP) was used as a standard fertilizer. R P and TSP with 50 mg P Kg-1 soil were incubated for 30 days to examine the fixing capacity of the acid soils. The results showed that Rangsit Soil which is acid sulfate had high fixing capacity. Pakchong soil retained higher P fixation ability than Korat and Warin soil series. The highest fixation capacity among 7 acid soils were Grey Soil and Mae Taeng soil series. The solubility of TSP was decreased when incorporated with soil after incubation for 30 days. P R from Ratchaburi showed higher effectiveness than Lamphun P R

1996-12-01

115

Effect of compaction energy on soil suction of clayey soils  

International Nuclear Information System (INIS)

Soil suction is a fundamental physical property of unsaturated soils such as buffer materials, shallow foundation, dam foundation and pavement sub-grades, describing the potential with which a given soil at given water content adsorbs and retains pore water. From a thermodynamic standpoint, soil suction is the free energy of pore-water in a soil and is a function of relative humidity or moisture. This study was undertaken to evaluate the variations of soil suction with the moisture content for clayey soils. In particular, the effects of compaction energy on soil suction were investigated. The suction of unsaturated soil was determined for various conditions, covering a range of compacting efforts and water contents. Soils specimens were prepared by dynamic compaction and were compacted using 3 levels of compacting effort. The filter paper method was used to measure the total and matrix suctions of two clayey soils. Findings from these tests indicated that low plasticity soils have lower soil suction than high plasticity soils at a specific water content. Soil suction was observed to increase markedly with decreasing compaction energy on soils at low water contents. And at high water contents, soil suction is relatively insensitive to compaction energy. It was also found that compaction energy has more impact on the total suction than the matrix suction. For soils prepared using impact compaction, void ratio was found not a good index to predict soil suction, while the degree of saturation shows a good correlation with soil suction and is proposed to be used as a predictor for soil suction. (authors)

2005-03-14

116

Soil studies. Soil inventory studies: mapping and description  

Energy Technology Data Exchange (ETDEWEB)

Soils on the Geokinetic Oil Shale Project site in Uintah County, Utah are described, classified and mapped. This interim report contains baseline information for soil series. Preliminary identification was made using black and white aerial photography and later verified in the field. Soil units are classified according to the USDA soil nomenclature. (DMC)

Olgeirson, E.R.

1979-01-01

117

Soils and runoff - a practical guide to examining soil structure  

…clip shows shows you how to examine soil structure, covering the soil surface, top soil, subsoil and different soil types. The clip provides an illustration of some the examples from the thinksoils manual. Get the Flash Player to see this player. * Read the video transcript (Word, 41KB)

118

Introductory Soil Science Exercises Using USDA Web Soil Survey  

Science.gov (United States)

The USDA, Natural Resource Conservation Service (NRCS) Web Soil Survey is a valuable teaching tool for soil science education. By incorporating the Web Soil Survey into an undergraduate-level course, students are able to use the most detailed digital soil survey information without the steep learning curve associated with geographic information…

Post, Christopher J.; Mikhailova, Elena; McWhorter, Christopher M.

2007-01-01

119

Climate Strategic Soil Management  

Directory of Open Access Journals (Sweden)

Full Text Available The complex and strong link between soil degradation, climate change and food insecurity is a global challenge. Sustainable agricultural systems must be integral to any agenda to address climate change and variability, improve renewable fresh water supply and quality, restore degraded soils and ecosystems and advance food security. These challenges are being exacerbated by increasing population and decreasing per capita arable land area and renewable fresh water supply, the increasing frequency of extreme events, the decreasing resilience of agroecosystems, an increasing income and affluent lifestyle with growing preference towards meat-based diet and a decreasing soil quality and use efficiency of inputs. Reversing these downward spirals implies the implementation of proven technologies, such as conservation agriculture, integrated nutrient management, precision agriculture, agroforestry systems, etc. Restoration of degraded soil and desertified ecosystems and the creation of positive soil and ecosystem C budgets are important. Urban agriculture and green roofs can reduce the energy footprint of production chains for urban and non-urban areas and enhance the recycling of by-products. Researchable priorities include sustainable land use and soil/water management options, judicious soil governance and modus operandi towards payments to land managers for the provisioning of ecosystem services.

Rattan Lal

2014-02-01

120

Iodine in soil  

International Nuclear Information System (INIS)

A literature study of the migration and the appearance of iodine isotopes in the bio-sphere particularly in soil is presented. Some important papers in the field of iodine appearance in soil and the appearance of "1"2"9I in the surroundings of reprocessing plants are discussed. The most important conclusions are: 1. Iodine binds to organic matter in the soil and also to some oxides of aluminium and iron. 2. If the iodine is not bound to the soil a large fraction of added "1"2"9I is volatilized after a rather short period. 3. The binding and also the volatilisation seems to be due to biological activity in the soil. It may take place within living microorganisms or by external enzymes excreted from microorganisms. 4. Due to variations in the composition of soil there may be a large variation in the distribution of "1"2"9I in the vertical profile of soil - usually most of the "1"2"9I in the upper layer - which also results in large variations in the "1"2"9I uptake to plants

2000-01-01

 
 
 
 
121

Parameterization of radiocaesium soil-plant transfer using soil characteristics  

International Nuclear Information System (INIS)

A model of radionuclide soil-plant transfer is proposed to parameterize the transfer factor by soil and soil solution characteristics. The model is tested with experimental data on the aggregated transfer factor T_a_g and soil parameters for 8 forest sites in Baden-Wuerttemberg. It is shown that the integral soil-plant transfer factor can be parameterized through radiocaesium exchangeability, capacity of selective sorption sites and ion composition of the soil solution or the water extract. A modified technique of (FES) measurement for soils with interlayer collapse is proposed. (author)

1996-11-01

122

SOIL Geo-Wiki: A tool for improving soil information  

Science.gov (United States)

Crowdsourcing is increasingly being used as a way of collecting data for scientific research, e.g. species identification, classification of galaxies and unravelling of protein structures. The WorldSoilProfiles.org database at ISRIC is a global collection of soil profiles, which have been 'crowdsourced' from experts. This system, however, requires contributors to have a priori knowledge about soils. Yet many soil parameters can be observed in the field without specific knowledge or equipment such as stone content, soil depth or color. By crowdsourcing this information over thousands of locations, the uncertainty in current soil datasets could be radically reduced, particularly in areas currently without information or where multiple interpretations are possible from different existing soil maps. Improved information on soils could benefit many research fields and applications. Better soil data could enhance assessments of soil ecosystem services (e.g. soil carbon storage) and facilitate improved process-based ecosystem modeling from local to global scales. Geo-Wiki is a crowdsourcing tool that was developed at IIASA for land cover validation using satellite imagery. Several branches are now available focused on specific aspects of land cover validation, e.g. validating cropland extent or urbanized areas. Geo-Wiki Pictures is a smart phone application for collecting land cover related information on the ground. The extension of Geo-Wiki to a mobile environment provides a tool for experts in land cover validation but is also a way of reaching the general public in the validation of land cover. Here we propose a Soil Geo-Wiki tool that builds on the existing functionality of the Geo-Wiki application, which will be largely designed for the collection and sharing of soil information. Two distinct applications are envisaged: an expert-oriented application mainly for scientific purposes, which will use soil science related language (e.g. WRB or any other global reference soil classification system) and allow experts to upload and share scientifically rigorous soil data; and an application oriented towards the general public, which will be more focused on describing well observed, individual soil properties using simplified classification keys. The latter application will avoid the use of soil science related terminology and focus on the most useful soil parameters such as soil surface features, stone content, soil texture, soil plasticity, calcium carbonate presence, soil color, soil pH, soil repellency, and soil depth. Collection of soil and landscape pictures will also be supported in Soil Geo-Wiki to allow for comprehensive data collection while simultaneously allowing for quality checking by experts.

Skalský, Rastislav; Balkovic, Juraj; Fritz, Steffen; See, Linda; van der Velde, Marijn; Obersteiner, Michael

2014-05-01

123

The Influence of Soil Particle on Soil Condensation Water  

Directory of Open Access Journals (Sweden)

Full Text Available The experiment results showed that the indoor experiment formed from the volume of soil hygroscopic water increased gradually with decreasing size of soil particles. In the outdoor experiments, the results showed that the formed condensation water in medium sand was greater than it was in fine sand; the soil hot condensation water was mainly formed in the top layer of soil between 0-5 cm. We also found that covering the soil surface with stones can increase the volume of formed soil condensate water, reduce the evaporation and maintain relatively high moisture content in the top layer of soil.

Hou Xinwei

2013-06-01

124

Development of soil taxation and soil classification as furthered by the Austrian Soil Science Society  

Science.gov (United States)

Soil taxation and soil classification are important drivers of soil science in Austria. However, the tasks are quite different: whereas soil taxation aims at the evaluation of the productivity potential of the soil, soil classification focusses on the natural development and - especially nowadays - on functionality of the soil. Since the foundation of the Austrian Soil Science Society (ASSS), representatives both directions of the description of the soil have been involved in the common actions of the society. In the first years it was a main target to improve and standardize field descriptions of the soil. Although both systems differ in the general layout, the experts should comply with identical approaches. According to this work, a lot of effort has been put into the standardization of the soil classification system, thus ensuring a common basis. The development, state of the art and further development of both classification and taxation systems initiated and carried out by the ASSS will be shown.

Baumgarten, Andreas

2013-04-01

125

Selenium in soil  

Directory of Open Access Journals (Sweden)

Full Text Available Selenium (Se is an essential microelement, necessary for normal functioning of human and animal organisms. Its deficiency in food and feed causes a number of diseases. In high concentrations, selenium is toxic for humans animals and plants. Soil provision with selenium affects its level in food and feed via nutrition chain. However, selenium reactivity and bioavailability depends not only on its total content in soil but also on its chemical forms. Distribution of the different forms of selenium depends on soil properties such as reaction, aeration, contents of clay and organic matter and microbiological activity.

?uvardi? Maja S.

2003-01-01

126

Soil Microbes and soil microbial proteins: interactions with clay minerals  

International Nuclear Information System (INIS)

Bacterial enumeration in soil environments estimates that the population may reach approximately 1010 g-1 of soil and comprise up to 90% of the total soil microbial biomass. Bacteria are present in soils as single cells or multicell colonies and often strongly adsorb onto mineral surfaces such as sand and clay. The interactions of microbes and microbial biomolecules with these minerals have profound impacts on the physical, chemical and biological properties of soils. (Author)

2008-09-00

127

THE DIRT ON SOILS  

Science.gov (United States)

This keynote presentation will provide basic information regarding the physical, chemical, and biological importance of soils to 50 second grade teachers within the Cincinnati Public School System as part of a Hamilton County Department of Environmenatl Services Sois Workshop....

128

Soils: Pressures and opportunities  

Sep 1, 2005 ... ... Potential to import plant and animal diseases that use soil as a host ... \\Improvement of air quality by removal of carbon dioxide, release of oxygen and \\water vapour, deposition of particulate pollutants, and absorption of ...

129

Soil erosion and conservation  

Energy Technology Data Exchange (ETDEWEB)

This is a review of worldwide land degradation problems. Four themes are emphasized: delineating and estimating the magnitude of soil erosion, quantifying erosion and sedimentation impacts on land productivity, establishing quantitative values for erosion-causing parameters, and implementing global and regional soil and water conservation programs. Papers deal with both developing and developed countries and illustrate how erosion control techniques used in developed countries can or cannot be applied in developing countries.

El-Swaify, S.A.; Moldenhauer, W.C.; Lo, A.

1985-01-01

130

Selenium in soil  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Selenium (Se) is an essential microelement, necessary for normal functioning of human and animal organisms. Its deficiency in food and feed causes a number of diseases. In high concentrations, selenium is toxic for humans animals and plants. Soil provision with selenium affects its level in food and feed via nutrition chain. However, selenium reactivity and bioavailability depends not only on its total content in soil but also on its chemical forms. Distribution of the different forms of sele...

?uvardi? Maja S.

2003-01-01

131

European Atlas of Soil Biodiversity  

DEFF Research Database (Denmark)

Soil is one of the fundamental components for supporting life on Earth. Most ecosystem processes and global functions that occur within soil are driven by living organisms that, in turn, sustain life above ground. However, despite the fact that soils are home to a quarter of all living species on Earth, life within the soil is often hidden away and suffers by being 'out of sight and out of mind'. What kind of life is there in soil? What do we mean by soil biodiversity? What is special about soil biology? How do our activities affect soil ecosystems? What are the links between soil biota and climate change? The first ever European Atlas of Soil Biodiversity uses informative texts, stunning photographs and maps to answer these questions and other issues. The European Atlas of Soil Biodiversity functions as a comprehensive guide allowing non-specialists to access information about this unseen world. The first part of the book provides an overview of the below ground environment, soil biota in general, the ecosystem functions that soil organism perform, the important value it has for human activities and relevance for global biogeochemical cycles. The second part is an 'Encyclopedia of Soil Biodiversity'. Starting with the smallest organisms such as the bacteria, this segment works through a range of taxonomic groups such as fungi, nematodes, insects and macro-fauna to illustrate the astonishing levels of heterogeneity of life in soil. The European Atlas of Soil Biodiversity is more than just a normal atlas. Produced by leading soil scientists from Europe and other parts of the world under the auspice of the International Year of Biodiversity 2010, this unique document presents an interpretation of an often neglected biome that surrounds and affects us all. The European Atlas of Soil Biodiversity is an essential reference to the many and varied aspects of soil. The overall goal of this work is to convey the fundamental necessity to safeguard soil biodiversity in order to guarantee life on this planet.

2010-01-01

132

Degradation and resilience of soils  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Debate on global soil degradation, its extent and agronomic impact, can only be resolved through understanding of the processes and factors leading to establishment of the cause-effect relationships for major soils, ecoregions, and land uses. Systematic evaluation through long-term experimentation is needed for establishing quantitative criteria of (i) soil quality in relation to specific functions; (ii) soil degradation in relation to critical limits of key soil properties and processes; and...

Lal, R.

1997-01-01

133

Optional Soil Moisture Sensor Protocol  

Science.gov (United States)

The purpose of this resource is to measure the water content of soil based on the electrical resistance of soil moisture sensors. Students install soil moisture sensors in holes that are 10 cm, 30 cm, 60 cm, and 90 cm deep. They take daily readings of soil moisture data by connecting a meter to the sensors and using a calibration curve to determine the soil water content at each depth.

The GLOBE Program, University Corporation for Atmospheric Research (UCAR)

2003-08-01

134

Control of soil erosion by polymeric soil conditioners  

Energy Technology Data Exchange (ETDEWEB)

Polyacrylamide polymers are useful in forming water-stable aggregates in soil. They not only have a favorable effect on water infiltration in soil, but also decrease the erodibility of soil. To stabilize soil, the polymers are either mixed dry with soil and then subjected to a wetting, drying, and cultivation cycle or solutions containing polymers are applied to cultivated soil. Five different situations where polymers can decrease soil erosion are described. The first situation involves application to soil several centimeters deep to improve water penetration, so that there is less water runoff and less erosion. The second situation involves application to the surface up to a 2-cm depth of soil to create water-stable aggregates that resist erosion. The third situation involves spraying polymers in solution or applying dry material followed by wetting onto the soil surface, so that after drying the stable structure of the surface of soil will not easily break during rain storms, even though water will penetrate, but with much running off. The soil may not be cultivated in this situation. The fourth situation involves applying polymers to soil via irrigation water to decrease soil erosion by the irrigation water, particularly from furrows. The fifth situation involves applying polymers to driveways and playing fields to decrease erosion of dust by wind. Tested rates of the polymers that inhibited erosion were much lower than those rates used for the product Krilium over 30 years ago.

Wallace, G.A.; Wallace, A.

1986-05-01

135

A modified soil water based Richards equation for layered soils  

Science.gov (United States)

Most Soil-Vegetation-Atmosphere-Transfer (SVAT) models like TERRA-ML (implemented e.g. in the CCLM model (www.clm-community.eu)) use the soil moisture based Richards equation to simulate vertical water fluxes in soils, assuming a homogeneous soil type. Recently, high-resolution soil type datasets (e.g. BüK 1000, only for Germany (Federal Institute for Geosciences and Natural Resources, BGR, www.bgr.bund.de) or Harmonized World Soil Database (HWSD, version 1.1, FAO/IIASA/ISRIC/ISSCAS/JRC, March 2009)) have been developed. Deficiencies in the numerical solution of the soil moisture based Richards equation may occur if inhomogeneous soil type data is implemented, because there are possibly discontinuities in soil moisture due to various soil type characteristics. One way to fix this problem is to use the potential based Richards equation, but this may lead to problems in conservation of mass. This presentation will suggest a possible numerical solution of the soil moisture based Richards equation for inhomogeneous soils. The basic idea is to subtract the equilibrium state of it from soil moisture fluxes. This should reduce discontinuities because each soil layer aspires the equilibrium state and therefore differences might be of the same order. First sensitivity studies have been done for the Main river basin, Germany.

Kalinka, F.; Ahrens, B.

2010-09-01

136

Soil physics and the water management of spatially variable soils  

International Nuclear Information System (INIS)

The physics of macroscopic soil-water behaviour in inert porous materials has been developed by considering water flow to take place in a continuum. This requires the flow region to consist of an assembly of representative elementary volumes, repeated throughout space and small compared with the scale of observations. Soil-water behaviour in swelling soils may also be considered as a continuum phenomenon so long as the soil is saturated and swells and shrinks in the normal range. Macroscale heterogeneity superimposed on the inherent microscale heterogeneity can take many forms and may pose difficulties in the definition and measurement of soil physical properties and also in the development and use of predictive theories of soil-water behaviour. Thus, measurement techniques appropriate for uniform soils are often inappropriate, and criteria for soil-water management, obtained from theoretical considerations of behaviour in equivalent uniform soils, are not applicable without modification when there is soil heterogeneity. The spatial variability of soil-water properties is shown in results from field experiments concerned with water flow measurements; these illustrate both stochastic and deterministic heterogeneity in soil-water properties. Problems of water management of spatially variable soils when there is stochastic heterogeneity appear to present an insuperable problem in the application of theory. However, for soils showing deterministic heterogeneity, soil-water theory has been used in the solution of soil-water management problems. Thus, scaling using similar media theory has been applied to the infiltration of water into soils that vary over a catchment area. Also, the drain spacing to control the water-table height in soils in which the hydraulic conductivity varies with depth has been calculated using groundwater seepage theory. (author)

1983-04-18

137

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

Directory of Open Access Journals (Sweden)

Full Text Available Soil respiration rates were measured along different parts of a slope in (a an evergreen forest with mature soil and (b a deciduous forest with immature soil. The effects of soil temperature, soil moisture, and soil properties on soil respiration rates were estimated individually, and the magnitudes of these effects were compared between the deciduous and evergreen forests. In the evergreen forest with mature soil, soil properties had the greatest effect on soil respiration rates, followed by soil moisture and soil temperature. These results may be explained by different properties of soils that matured under different environments. Thus, we argue that the low soil respiration rates in Plot L of 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, which were likely due to the immaturity of the forest soil.

K. Tamai

2009-11-01

138

Pesticide-soil microflora interactions in flooded rice soils  

International Nuclear Information System (INIS)

Isotope studies revealed that gamma and beta isomers of HCH (hexachlorocyclohexane) decomposed rapidly in nonsterile soils capable of attaining redox potentials of -40 to -100mV within 20 days after flooding. Degradation was slow, however, in soils low in organic matter and in soils with extremely low pH and positive potentials, even after several weeks of flooding. Under flooded conditions, endrin decomposed to six metabolites in most soils. There is evidence that biological hydrolysis of parathion is more widespread than hitherto believed, particularly under flooded soil conditions. Applications of benomyl (fungicide) to a simulated-oxidized zone of flooded soils favoured heterotrophic nitrification. (author)

1976-01-01

139

GLOBE Videos: Soil Characterization - Soil Moisture (18:23 min)  

Science.gov (United States)

This video describes how to select a soil moisture study site and sampling strategy, and identifies what laboratory instruments will be needed to complete a soil moisture analysis. Students are shown collecting soil moisture data and asking questions about what soil moisture data might tell them about the environment. The resource includes a video and a written transcript, and is supported by the Soil Moisture Protocol in the GLOBE Teacher's Guide. This is one of five videos about soils in the 24-part instructional video series describing scientific protocols used by GLOBE (Global Learning and Observation to Benefit the Environment), a worldwide, hands-on, K-12 school-based science education program.

140

Effects of Land Cover / Land Use, Soil Texture, and Vegetation on the Water Balance of Lake Chad Basin  

Science.gov (United States)

Lake Chad Basin (LCB) has experienced drastic changes of land cover and poor water management practices during the last 50 years. The successive droughts in the 1970s and 1980s resulted in the shortage of surface water and groundwater resources. This problem of drought has a devastating implication on the natural resources of the Basin with great consequence on food security, poverty reduction and quality of life of the inhabitants in the LCB. Therefore, understanding the effects of land use / land cover must be a first step to find how they disturb cycle especially the groundwater in the LCB. The abundance of groundwater is affected by the climate change through the interaction with surface water, such as lakes and rivers, and disuse recharge through an infiltration process. Quantifying the impact of climate change on the groundwater resource requires reliable forecasting of changes in the major climatic variables and other spatial variations including the land use/land cover, soil texture, topographic slope, and vegetation. In this study, we employed a spatially distributed water balance model WetSpass to simulate a long-term average change of groundwater recharge in the LCB of Africa. WetSpass is a water balance-based model to estimate seasonal and spatial distribution of surface runoff, interception, evapotranspiration, and groundwater recharge. The model is especially suitable for studying the effect of land use/land cover change on the water regime in the LCB. The present study describes the concept of the model and its application to the development of recharge map of the LCB. The study shows that major role in the water balance of LCB. The mean yearly actual evapotranspiration (ET) from the basin range from 60mm - 400 mm, which is 90 % (69mm - 430) of the annual precipitation from 2003 - 2010. It is striking that about 50 - 60 % of the total runoff is produced on build-up (impervious surfaces), while much smaller contributions are obtained from vegetated, bare soil and open water surfaces. The result of this study also shows that runoff is high in the clay, clay loam and sandy-clay loam due to the lack of infiltration process in clay soil from capping or crusting or sealing of the soil pores, therefore this situation will aid runoff. The application of the WetSpass model shows that precipitation, soil texture and land use / land cover are three controlling factors affecting the water balance in the LCB. Key words: Groundwater recharge, surface runoff, evapotranspiration, water balance, meteorological, draught, Landuse changes, climate changes, WetSpass, GIS.

Babamaaji, R. A.; Lee, J.

2013-12-01

 
 
 
 
141

Soil ingestion by dairy cattle  

Energy Technology Data Exchange (ETDEWEB)

Ingested soil may be a source of minerals to grazing cattle; it may also be a source of radionuclides, heavy metals, and organic toxins. The importance of soil ingestion in the milk pathway depends on the amount of soil ingested, the ratio of the mineral concentration in soil to that in herbage, and the ability of the cattle to solubilize and absorb the soil-derived minerals. The amount of soil ingested by cattle on pasture, in turn, depends upon the stocking level, the quantity of forage available, and the soil ingesting propensity of individual cows. The objective of this note is to summarize some of the information about soil ingestion by dairy cattle and to suggest methods for incorporating soil ingestion into the Hanford Environmental Dose Reconstruction (HEDR) Phase I milk model. 5 refs., 4 tabs.

Darwin, R.

1990-02-15

142

Shrinking Behaviour of Badland Soil Under Different Soil Covers  

Directory of Open Access Journals (Sweden)

Full Text Available Indicators used to estimate the soil structure stability facing erosion are the basis of major indicators of soil quality, and their behaviour is affected by permanent soil properties, vegetation and management. The relation between the pore-volume fraction occupied by water and the pore size distribution in clay soils is studied by the shrinkage curve describing clay soil porosity dynamics as a function of soil moisture. The aim of this work is to study the shrinking behaviour of the surface soil in a badland site through the shrinkage curve and to assess its relations with vegetation. Six treatments with different soil vegetation cover and aspect were selected on a badland site in Pisticci (Southern Italy. Shrinkage curves were built from natural aggregates collected in the 0-10 cm soil depth. Soil stability under shaking in water was also determined, with pre-treatments in water, alcohol and benzene for the determination of the SSI (Soil Stability Index. Soil organic matter, electrical conductivity, ESP were determined in order to investigate the relations between soil cover, chemical properties, SSI and shrink-swell behaviour. Vegetation was associated with lower soil salinity and ESP, and higher soil organic matter content. Vegetated sites showed a higher SSI and a lower overall swelling. The shrinkage curves for samples from vegetated areas lack of the structural phase of shrinkage, likely due to the combined effect of lower ESP and the mechanical effect of plant roots. All soil properties and indicators point to a higher stability of soils under grass in the south aspect and under shrub in the north one.

Teodoro Di Tommaso

143

Shrinking Behaviour of Badland Soil Under Different Soil Covers  

Directory of Open Access Journals (Sweden)

Full Text Available Indicators used to estimate the soil structure stability facing erosion are the basis of major indicators of soil quality, and their behaviour is affected by permanent soil properties, vegetation and management. The relation between the pore-volume fraction occupied by water and the pore size distribution in clay soils is studied by the shrinkage curve describing clay soil porosity dynamics as a function of soil moisture. The aim of this work is to study the shrinking behaviour of the surface soil in a badland site through the shrinkage curve and to assess its relations with vegetation. Six treatments with different soil vegetation cover and aspect were selected on a badland site in Pisticci (Southern Italy. Shrinkage curves were built from natural aggregates collected in the 0-10 cm soil depth. Soil stability under shaking in water was also determined, with pre-treatments in water, alcohol and benzene for the determination of the SSI (Soil Stability Index. Soil organic matter, electrical conductivity, ESP were determined in order to investigate the relations between soil cover, chemical properties, SSI and shrink-swell behaviour. Vegetation was associated with lower soil salinity and ESP, and higher soil organic matter content. Vegetated sites showed a higher SSI and a lower overall swelling. The shrinkage curves for samples from vegetated areas lack of the structural phase of shrinkage, likely due to the combined effect of lower ESP and the mechanical effect of plant roots. All soil properties and indicators point to a higher stability of soils under grass in the south aspect and under shrub in the north one.

Michele Perniola

2011-02-01

144

Soil property effects on wind erosion of organic soils  

Science.gov (United States)

Histosols (also known as organic soils, mucks, or peats) are soils that are dominated by organic matter (OM > 20%) in half or more of the upper 80 cm. Forty two states have a total of 21 million ha of Histosols in the United States. These soils, when intensively cropped, are subject to wind erosion resulting in loss of crop productivity and degradation of soil, air, and water quality. Estimating wind erosion on Histosols has been determined by USDA-Natural Resources Conservation Service (NRCS) as a critical need for the Wind Erosion Prediction System (WEPS) model. WEPS has been developed to simulate wind erosion on agricultural land in the US, including soils with organic soil material surfaces. However, additional field measurements are needed to understand how soil properties vary among organic soils and to calibrate and validate estimates of wind erosion of organic soils using WEPS. Soil properties and sediment flux were measured in six soils with high organic contents located in Michigan and Florida, USA. Soil properties observed included organic matter content, particle density, dry mechanical stability, dry clod stability, wind erodible material, and geometric mean diameter of the surface aggregate distribution. A field portable wind tunnel was used to generate suspended sediment and dust from agricultural surfaces for soils ranging from 17% to 67% organic matter. The soils were tilled and rolled to provide a consolidated, friable surface. Dust emissions and saltation were measured using an isokinetic vertical slot sampler aspirated by a regulated suction source. Suspended dust was sampled using a Grimm optical particle size analyzer. Particle density of the saltation-sized material (>106 ?m) was inversely related to OM content and varied from 2.41 g cm-3 for the soil with the lowest OM content to 1.61 g cm-3 for the soil with highest OM content. Wind erodible material and the geometric mean diameter of the surface soil were inversely related to dry clod stability. The effect of soil properties on sediment flux varied among flux types. Saltation flux was adequately predicted with simple linear regression models. Dry mechanical stability was the best single soil property linearly related to saltation flux. Simple linear models with soil properties as independent variables were not well correlated with PM10E values (mass flux). A second order polynomial equation with OM as the independent variable was found to be most highly correlated with PM10E values. These results demonstrate that variations in sediment and dust emissions can be linked to soil properties using simple models based on one or more soil properties to estimate saltation mass flux and PM10E values from organic and organic-rich soils.

Zobeck, Ted M.; Baddock, Matthew; Scott Van Pelt, R.; Tatarko, John; Acosta-Martinez, Veronica

2013-09-01

145

Lasagna trademark soil remediation  

International Nuclear Information System (INIS)

Lasagna trademark is an integrated, in situ remediation technology being developed which remediates soils and soil pore water contaminated with soluble organic compounds. Lasagna trademark is especially suited to sites with low permeability soils where electroosmosis can move water faster and more uniformly than hydraulic methods, with very low power consumption. The process uses electrokinetics to move contaminants in soil pore water into treatment zones where the contaminants can be captured and decomposed. Initial focus is on trichloroethylene (TCE), a major contaminant at many DOE and industrial sites. Both vertical and horizontal configurations have been conceptualized, but fieldwork to date is more advanced for the vertical configuration. Major features of the technology are electrodes energized by direct current, which causes water and soluble contaminants to move into or through the treatment layers and also heats the soil; treatment zones containing reagents that decompose the soluble organic contaminants or adsorb contaminants for immobilization or subsequent removal and disposal; and a water management system that recycles the water that accumulates at the cathode (high pH) back to the anode (low pH) for acid-base neutralization. Alternatively, electrode polarity can be reversed periodically to reverse electroosmotic flow and neutralize pH

1996-01-01

146

Soil Particle Size Distribution Protocol  

Science.gov (United States)

The purpose of this resource is to sure the distribution of different sizes of soil particles in each horizon of a soil profile. Using dry, sieved soil from a horizon, students mix the soil with water and a dispersing solution to completely separate the particles from each other. Students shake the mixture to fully suspend the soil in the water. The soil particles are then allowed to settle out of suspension, and the specific gravity and temperature of the suspension are measured using a hydrometer and thermometer. These measurements are taken after 2 minutes and 24 hours.

The GLOBE Program, University Corporation for Atmospheric Research (UCAR)

2003-08-01

147

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

Science.gov (United States)

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 vulnerabil...

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

1998-01-01

148

SOIL AND LEACHED BLACK SOIL ENVIRONMENTAL EVALUATION OF WEST CAUCASUS ????????-????????????? ?????? ????????? ????????????? ????????? ????????????  

Directory of Open Access Journals (Sweden)

Full Text Available The analysis of foreign and domestic methods to evaluate soil productivity sowings has been presented. It has shown the need for soil environmental assessment in the West Central Caucasus. The soil-environmental index and index scores for an experimental field of individual crops rotation, which will promptly assess the fertility of the soil, give recommendations for rational allocation of fertilizer has been given

Slyusarev V. N.

2013-05-01

149

Analysis of soil variability measured with a soil strength sensor  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In the context of precision agriculture, the knowledge of soil strength variability at the field scale may be useful for improving site-specific tillage. Moreover, rapid and accurate sensing methods for soil physical properties determination would favourably replace labour intensive, time-consuming and expensive soil sampling and analysis. This study aims at validating conclusions of a previous study which was conducted to develop a soil strength in field conditions. The coupled acquisition o...

2004-01-01

150

Soil moisture distribution over time in a clay loam soil in Kosovo  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Studying the soil moisture distribution over time in a given soil profile is the object of the present study. The way the soil moisture gets distributed over soil profile depends particularly on the soil texture and on the soil suction gradients developed. However, it changes continuously over time for a given soil depth. The method of determining the soil moisture distribution over time is based on the measuring of soil moisture suctions developed and the soil moisture contents in various ti...

Abdullah Nishori; Besnik Gjongecaj; Deme Abazi

2013-01-01

151

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Tamai, K.

2009-01-01

152

Soils and geomedicine.  

Science.gov (United States)

Geomedicine is the science dealing with the influence of natural factors on the geographical distribution of problems in human and veterinary medicine. Discussions on potential harmful impacts on human and animal health related to soil chemistry are frequently focused on soil pollution. However, problems related to natural excess or deficiency of chemical substances may be even more important in a global perspective. Particularly problems related to trace element deficiencies in soils have been frequently reported in agricultural crops as well as in livestock. Deficiencies in plants are often observed for boron, copper, manganese, molybdenum, and zinc. In animals deficiency problems related to cobalt, copper, iodine, manganese, and selenium are well known. Toxicity problems in animals exposed to excess intake have also been reported, e.g., for copper, fluorine, and selenium. Humans are similar to mammals in their relations to trace elements and thus likely to develop corresponding problems as observed in domestic animals if their supply of food is local and dependent on soils providing trace element imbalances in food crops. In large parts of Africa, Asia, and Latin America, people depend on locally grown food, and geomedical problems are common in these parts of the world. Well-known examples are Keshan disease in China associated with selenium deficiency, large-scale arsenic poisoning in Bangladesh and adjacent parts of India, and iodine deficiency disorders in many countries. Not all essential elements are derived only from the soil minerals. Some trace elements such as boron, iodine, and selenium are supplied in significant amounts to soils by atmospheric transport from the marine environment, and deficiency problems associated with these elements are therefore generally less common in coastal areas than farther inland. For example, iodine deficiency disorders in humans are most common in areas situated far from the ocean. There is still a great need for further research on geomedical problems. PMID:19350398

Steinnes, Eiliv

2009-10-01

153

Soil solution assessment of the soil availability of xenobiotics  

Energy Technology Data Exchange (ETDEWEB)

Soil solution displacement provides a means whereby xenobiotic availability in the soil environment can be evaluated rapidly and effectively. The displacement and analysis of soil solution provides (a) refined measurements of the bioavailability of soil active xenobiotics, (b) static measurements of phase partitioning of xenobiotics under conditions which closely mimic soil moisture regimes in field environments, and (c) dynamic measurements of xenobiotic availability as a function of residence time in the soil. The biological availability (efficacy/toxicity) and the geochemical availability (environmental fate) of biologically active molecules are both a function of the xenobiotic effective concentration (that is, chemical activity) and solid-liquid distribution in soils is possible based on knowledge of xenobiotic pK{sub a} and mole weight, and measurement of soil solution xenobiotic intensity, pH, and ionic strength. Dynamic measures based on soil solution displacement with time offer a means to assess time domain influences on xenobiotic availability. Soil solution displacement and analysis has been employed successfully for refined assessments of leachability, phytotoxicity, and sorptivity of xenobiotics and offers a useful adjunct to more traditional whole soil extractions for determination of xenobiotic fate and behavior in soil.

Wolt, J.D. [DowElanco, Indianapolis, IN (United States). North American Environmental Chemistry Lab.

1993-12-01

154

Soil contamination studies  

International Nuclear Information System (INIS)

The objective of this project was to develop a quick screening method that accurately identifies and quantifies the amount of alpha-emitting radionuclides in infinitely-thick soil samples using a Frisch grid ionization chamber. An additional objective of the work was to provide the US Department of Energy, Nevada Operations Office and its contractors with information on the theoretical and actual measured results of atmospheric testing contamination of soil and water at the Nevada Test Site through a comprehensive search of existing literature

1997-01-01

155

Soil and ground cover  

International Nuclear Information System (INIS)

The monitoring programmes set up in accordance with the directives for the surveillance of effluents from nuclear installations oblige operators of such installations to take samples of vegetation (grass) and soil twice a year at the least favourable place in the industrial plant's environment, and at a reference site, for radioactivity monitoring by gamma spectroscopy. In addition, the samples are to be examined for their Sr-90 content. Data recorded over the years show that nuclear facilities do not significantly contribute to soil and vegetation contamination with Sr-90 or Cs-137. The directives require regular interlaboratory comparisons, which are coordinated by the directing centre at Kiel. (DG)

1985-01-01

156

CONSIDERATIONS ON SOIL CARBON MANAGEMENT  

Directory of Open Access Journals (Sweden)

Full Text Available Soil organic carbon is important for the functioning of ecosystems andagro-ecosystems, having a major influence on the physical structure of the soil and its ability to store water. Loss of soil organic carbon can therefore lead to a reduction in soil fertility and land degradation. The content of organic carbon in a soil is determined by losses of organic carbon (through decomposition, erosion of particlesand losses through dissolved organic matter and inputs of organic carbon.Thus, worldwide, soil management to increase the content of soil organic carbon involves measures that reduce losses and/or measures that increase inputs. Carbon management is important for many problems that involve soils.

Adriana Nicoleta Ungura?u

2012-10-01

157

Strontium Sorption onto SRP Soils  

Energy Technology Data Exchange (ETDEWEB)

This report discusses the effect of water and soil quality variables on the sorption of strontium onto SRP soils. The variables cover the range of conditions observed in the low-level waste burial ground.

Hoeffner, S.L.

2001-07-02

158

Soil texture; 1 : 500 000  

International Nuclear Information System (INIS)

The characteristics of soil texture are based on an abundant database of the agricultural and forest soils. The character of the texture of the upper soil horizons is assessed. The colour scale represents the classes of texture, and the raster distinguishes the individual classes of stoniness (in mountain ranges) or graveliness in the river alluvia. Soils with at least 10 % of area representation of rock basement are classified as very rocky. Very rocky soils are mostly rankers to Lithosols in the mountain areas of Slovakia. Medium stony are Cambisols to rankers on the crystalline rocks and volcanic complexes. The relatively heaviest soils are to be found in the Vychodoslovenska nizina Lowland, the lightest soils occur in the Zahorska nizina Lowland with prevalence of soils on aeolian sands. (authors)

2002-01-01

159

Magnetic soil properties in Ghana  

Science.gov (United States)

In this paper we present the results of a study of some soil magnetic properties in Ghana. The soils sampled formed in different parent materials: Granites, Birimian rocks, and Voltaian sandstones. We discuss the role of environmental controls such as parent material, soil drainage, and precipitation on the magnetic properties. The main conclusion of this reconnaissance study is that the eight different soil types sampled have their own unique magnetic signature. Future research will have to confirm whether this conclusion holds for other soils in Ghana. If it does, the measurement of magnetic soil properties may become a viable complement for the investigation of soil erosion, land degeneration, and pedogenesis. The magnetic soil properties measured would probably not pose any limitations for the use of electromagnetic sensors for the detection of land mines and UXO.

Hendrickx, Jan M. H.; Harrison, J. Bruce J.; van Dam, Remke L.; Borchers, Brian; Norman, David I.; Dedzoe, Christian D.; Antwi, B. O.; Asiamah, R. D.; Rodgers, Charles; Vlek, Paul; Friesen, Jan

2005-06-01

160

Soil bioassay: Problems and approaches  

Science.gov (United States)

The methodological and organizational problems of the practical application of soil bioassay to monitor the state of soils for environmental, agricultural, and sanitary-epidemiological purposes are analyzed. To improve the efficiency of the integral valuation of soil toxicity, soil bioassay should be performed with a set of organisms (sensors) representing the major trophic levels of the ecosystems, i.e., producers, consumers, and decomposers.

Terekhova, V. A.

2011-02-01

 
 
 
 
161

Soil, a sponge for pollutants  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This preface of the special issue entitled "Soil Pollutants" (Analusis Magazine 25, M16-M72, 1997) highlights major basic and applied issues about the sources and fate of organic, mineral and radioactive pollutants in soils. Soils have long been considered as a closed and inert medium where wastes can be dumped without impact on living organisms. This is false and we know now that soils play a vital role in ecosystems. Pollution sources are diverse and numerous. Toxic compounds are either of ...

Lichtfouse, Eric

1997-01-01

162

The soil reference shrinkage curve  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A recently proposed model showed how a clay shrinkage curve is transformed to the soil shrinkage curve at the soil clay content higher than a critical one. The objective of the present work was to generalize this model to the soil clay content lower a critical one. I investigated (i) the reference shrinkage curve, that is, one without cracks; (ii) the superficial layer of aggregates, with changed pore structure compared with the intraaggregate matrix; and (iii) soils with su...

Chertkov, V. Y.

2014-01-01

163

Sustainable Soil Water Management Systems  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Soil quality and its management must be considered as key elements for an effective management of water resources, given that the hydrological cycle and land management are intimately linked (Bossio et al. 2007). Soil degradation has been described by Bossio et al. (2010) as the starting point of a negative cycle of soil-water relationships, creating a positive, self-accelerating feedback loop with important negative impacts on water cycling and water productivity. Therefore, sustainable soil...

Basch, G.; Kassam, A.; Friedrich, T.; Santos, F. L.; Gubiani, P. I.; Calegari, A.; Reichert, J. M.; Dos Santos, D. R.

2012-01-01

164

The Science of Soil Textures  

Science.gov (United States)

Off-road motorcycle racing and ATV riding. Gardening and fishing. What do these high-adrenaline and slower-paced pastimes have in common? Each requires soil, and the texture of that soil has an effect on all of them. In the inquiry-based lessons described here, students work both in the field or laboratory and in the classroom to collect soil…

Bigham, Gary

2010-01-01

165

Soil ingestion by dairy cattle.  

Science.gov (United States)

Ingested soil may be a source of minerals to grazing cattle; it may also be a source of radionuclides, heavy metals, and organic toxins. The importance of soil ingestion in the milk pathway depends on the amount of soil ingested, the ratio of the mineral ...

R. Darwin

1990-01-01

166

Soil Erosion Control After Wildfire  

Science.gov (United States)

The potential for severe soil erosion is a consequence of wildfire because as a fire burns it destroys important plant material and the litter layer that stabilizes soil and slows water movement after severe rainstorms. This information sheet discusses how intense heat from fire can make soils hydrophobic, or water repellent, and identifies the actions landowners can take to minimize erosion after a fire.

167

Camelina Evaluation for Soil Amendment.  

Science.gov (United States)

The objective os this research was to determine if amendment of soil with camelina meal of camelina pellets could improve the establishment of native plants in disturbed soils. Camelina meal has never been evaluated as a soil amendment; yet, it has severa...

R. Ament

2011-01-01

168

[soils tech transcript.doc  

…problem. And the reason why I'm looking at soil structure and the state of soils is mainly in relation to run-off. Run-off leads to sediment loss, pesticide loss, nutrient loss. In fact anything that's on the field will run off if the soil structure's not right. So that's the water quality side and the…

169

[soils tech transcript.doc  

…are few air spaces, the soil is dense, tightly packed together and the water can't drain through the soil.'' ``This field here has been shallow cultivated. It hasn't be ploughed. The top is actually quite good, we can just take that off there. It comes off - nice, loose, soil structure. So this is still…

170

Soil-Transmitted Helminth Infections  

Science.gov (United States)

Soil-transmitted helminth infections Fact sheet N°366 Updated April 2014 Key facts Soil-transmitted helminth infections are caused by different species ... eggs present in human faeces, which contaminate the soil in areas where sanitation is poor. Approximately two ...

171

SOIL SURVEY GEOGRAPHIC DATABASE (SSURGO)  

Science.gov (United States)

This data set is a digital soil survey and is the most detailed level of soil geographic data developed by the National Cooperative Soil Survey. This data set consists of georeferenced digital map data and computerized attribute data. The map data are in a 7.5 minute quadrangle ...

172

Soil threats and soil protection: the role of biotechnology  

International Nuclear Information System (INIS)

The concept of soil conservation/soil protection in its wider sense has undergone important changes through history. Perceptions of soil as a crucial base of life in ancient cultures progressively evolved to a more pragmatic vision, with close connection to food production for survival. For centuries, agrarian production and the provision of food for humankind remained the main and crucial vision of the interaction of societies with soil. However, there are also some other new and important concepts related to soil which have progressively developed. (Author)

2008-09-00

173

Collapsible Soils in Louisiana.  

Science.gov (United States)

In southwest Louisiana, some surface silts (up to 3 feet deep) collapse under load after moisture is added. These soils were indistinguishable from nearby normal silts through routine tests. The deposits occur as low, gently-sloping ridges. Very similar c...

A. Arman S. I. Thornton

1972-01-01

174

Probe for soil examination  

International Nuclear Information System (INIS)

A probe is suggested which makes it possible that samples of the soil can be brought into the laboratory undestroyed in the form of columns. The probe is provided with an exchangeable, thinwalled tube of tin or synthetic material in its interior which is brought to the laboratory together with the sample. The subclaims refer to constructive details of the device. (UWI)

1977-01-01

175

Soil on Phoenix's MECA  

Science.gov (United States)

This image shows soil delivery to NASA's Phoenix Mars Lander's Microscopy, Electrochemistry and Conductivity Analyzer (MECA). The image was taken by the lander's Surface Stereo Imager on the 131st Martian day, or sol, of the mission (Oct. 7, 2008). At the bottom of the image is the chute for delivering samples to MECA's microscopes. It is relatively clean due to the Phoenix team using methods such as sprinkling to minimize cross-contamination of samples. However, the cumulative effect of several sample deliveries can be seen in the soil piles on either side of the chute. On the right side are the four chemistry cells with soil residue piled up on exposed surfaces. The farthest cell has a large pile of material from an area of the Phoenix workspace called 'Stone Soup.' This area is deep in the trough at a polygon boundary, and its soil was so sticky it wouldn't even go through the funnel. One of Phoenix's solar panels is shown in the background of this image. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

2008-01-01

176

Antimony deposition in soils  

International Nuclear Information System (INIS)

The current and potential pollution of soils with antimony is hardly known. Data are introduced on emissions and atmospheric pollution; in connection with the environmental behavior of antimony, they show a hazard potential that is higher than assumed up to now. In the interest of precaution, it is recommeded to treat antimony like arsenic. (orig.)

1990-05-15

177

How soil shapes the landscape  

Science.gov (United States)

There has been an increase in interest in quantitative modelling of soil genesis, which can provide prediction of environmental changes through numerical models. Modelling soil formation is a difficult task because soil itself is highly complex with interactions between water, inorganic materials and organic matter. This paper will provide a review on the research efforts of modelling soil genesis, their connection with landscape models and the inexorable genesis of the IUSS soil landscape modelling working group. Quantitative modelling soil formation using mechanistic models have begun in the 1980s such as the 'soil deficit' model by Kirkby (1985), Hoosbeek & Bryant's pedodynamic model (1992), and recently the SoilGen model by Finke (2008). These profile models considered the chemical reactions and physical processes in the soil at the horizon and pedon scale. The SoilGen model is an integration of sub-models, such as water and solute movement, heat transport, soil organic matter decomposition, mineral dissolution, ion exchange, adsorption, speciation, complexation and precipitation. The model can calculate with detail the chemical changes and materials fluxes in a profile and has been successfully applied. While they can simulate soil profile development in detail, there is still a gap how the processes act in the landscape. Meanwhile research in landscape formation in geomorphology is progressing steadily over time, slope development models model have been developed since 1970s (Ahnert, 1977). Soil was also introduced in a landscape, however soil processes are mainly modelled through weathering and transport processes (Minasny & McBratney 1999, 2001). Recently, Vanwalleghem et al. (2013) are able to combine selected physical, chemical and biological processes to simulate a full 3-D soil genesis in the landscape. Now there are research gaps between the 2 approaches: the landscape modellers increasingly recognise the importance of soil and need more detailed soil processes, and the soil profile modellers need to consider material fluxes at the landscape scale. The IUSS working group (WG) on modelling of soil and landscape evolution has been recently proposed, accepted and established. The WG tries to engage scientists (landscape and pedon scale modellers, critical zone scientists, palaeopedologists, process-quantifying pedologists, and others) to work actively together towards a better soil-landscape model. Some aspects of the work include (i) improving ways to generate boundary conditions (climate, vegetation, human impacts) along the timeline, both at landscape and pedon scale; (ii) better model validation and its consequences for data collection; (iii) finding a more efficient simulation algorithms (iv) an inventory of the (mis-)match between present and needed process coverage to answer societal questions on soil behavior under global change.

Minasny, Budiman; Finke, Peter; Vanwalleghem, Tom Tom; Stockmann, Uta; McBratney, Alex

2014-05-01

178

Wood-soil interactions in soil bioengineering slope stabilization works  

Directory of Open Access Journals (Sweden)

Full Text Available In this work we propose the use of soil quality indicators with the aim of assessing the environmental impact of soil bioengineering works. This study was carried out in central Italy where soil bioengineering slope stabilization works were established using chestnut wood. In particular the goal of this study was to determine the occurrence of a wood-effect, that is changes of soil properties due to the presence of decomposing logs in two sites characterized by different time span since works setting up. The presence of the logs did not affect soil physico-chemical properties. Conversely, soil biochemical properties such as soil microbial biomass, basal and cumulative respiration activities as well as microbial indexes, were influenced by the presence of the logs confirming the role of these bioindicators as early predictors of changes occurring in soil. Although a general positive trend was observed for the biochemical properties at both sites with respect to the control soils, significant differences were recorded mainly at the site where works were established six years before soil sampling. Soil bioengineering slope stabilization works establish a positive feed-back which ultimately can benefit plants; in fact the increase in microbial mineralization activity can enhance nutrient cycling and thus promote adequate growth conditions for the plant cuttings used in the wooden-work.

Moscatelli MC

2009-10-01

179

Geotechnical Properties of Soil-Ball Milled Soil Mixtures  

Science.gov (United States)

Laboratory experiments were conducted to study the fundamental geotechnical properties of mixtures of natural soils and its product after ball milling operation. The product after ball milling process is termed nano-soil herein. SEM analysis showed that much more nano size particles were obtained after the milling process. Testing and comparison of the properties of original kaolinite, montmorillonite and UKM soil with regard to its liquid limit, plastic limit, plasticity index, and specific surface and after addition of its nano-soil were also conducted. Laboratory tests results showed that the values of liquid limit and plastic limits were higher after nano-soil addition. However, its plasticity index reduces which is advantageous in many geotechnical constructions. Compressive strength of original soil-cement-1% nano-soil mixture showed almost double its value without nano-soil. It demonstrated that a small amount of these crushed particles or nano-soil can provide significant improvement in the geotechnical properties of soil. Thus, nanoparticles are potentially suitable for improving the properties of soil/clay for various applications.

Taha, M. R.

180

Soil washing results for mixed waste pond soils at Hanford  

Energy Technology Data Exchange (ETDEWEB)

Soil washing technology was assessed as a means for remediating soil contaminated with mixed wastes primarily composed of heavy metals and radionuclides. The soils at the US Department of Energy's Hanford Site are considered suitable for soil washing because of their relatively low quantities of silt and clay. However, in a limited number of soil washing experiments using soils from different locations in the north pond of the 300 Area, the degree of decontamination achieved for the coarse fraction of the soil varied considerably. Part of this variation appears to be due to the presence of a discrete layer of contaminated sediment found in some of the samples. 7 refs., 2 figs., 4 tabs.

Gerber, M.A.

1991-09-01

 
 
 
 
181

Bioavailability of radiocaesium in soil: parameterization using soil characteristics  

Energy Technology Data Exchange (ETDEWEB)

It has been shown that radiocaesium availability to plants strongly influenced by soil properties. For the best evaluation of TFs it necessary to use mechanistic models that predict radionuclide uptake by plants based on consideration of sorption-desorption and fixation-remobilization of the radionuclide in the soil as well as root uptake processes controlled by the plant. The aim of the research was to characterise typical Russian soils on the basis of the radiocaesium availability. The parameter of the radiocaesium availability in soils (A) has been developed which consist on radiocaesium exchangeability; CF -concentration factor which is the ratio of the radiocaesium in plant to that in soil solution; K{sub Dex} - exchangeable solid-liquid distribution coefficient of radiocaesium. The approach was tested for a wide range of Russian soils using radiocaesium uptake data from a barley pot trial and parameters of the radiocaesium bioavailability. Soils were collected from the arable horizons in different soil climatic zones of Russia and artificially contaminated by {sup 137}Cs. The classification of soils in terms of the radiocaesium availability corresponds quite well to observed linear relationship between {sup 137}Cs TF for barley and A. K{sub Dex} is related to the soil radiocaesium interception potential (RIP), which was found to be positively and strongly related to clay and physical clay (<0,01 mm) content. The {sup 137}Cs exchangeability were found to be in close relation to the soil vermiculite content, which was estimated by the method of Cs{sup +} fixation. It's shown radiocaesium availability to plants in soils under study can be parameterized through mineralogical soil characteristics: % clay and the soil vermiculite content. (author)

Syssoeva, A.A.; Konopleva, I.V. [Russian Institute of Agricultural Radiology and Agroecology, Obninsk (Russian Federation)

2004-07-01

182

Soil burial contribution to deep soil organic carbon storage  

Science.gov (United States)

Previous reviews of deep soil C have focused on root inputs and the vertical transport of particulate and dissolved organic matter through mixing, gravity, and preferential flowpaths as the main modes of delivery of C to the deep subsoil. Depositional processes have received considerable attention in the context of long-range soil erosion and sedimentation on land, but the role of soil burial in the sequestration of C photosynthesized in situ at depositional sites has been largely absent from discussions of deep soil organic C (SOC) dynamics. Burial can disconnect a soil from atmospheric conditions and slow or inhibit microbial decomposition. Buried soil horizons, which are former surface soils that have been buried through various depositional processes, can store more SOC than would exist at such depths from in situ root inputs and leaching from upper horizons. Here, we discuss factors contributing to SOC storage in soils below 1 m with a focus on soil burial. We review the contributions of geomorphic and anthropogenic depositional processes to deep SOC storage and describe how environmental conditions or state factors during and since burial influence SOC persistence in buried soils. We draw from examples in the paleosol and geomorphology literature to identify the effects of soil burial by volcanic, aeolian, alluvial, colluvial, glacial, and anthropogenic processes on soil C storage. Buried soils have been traditionally studied for information about past environments and can also serve as useful case studies for understanding both the sensitivity of landscape processes to future environmental change and the mechanisms contributing to soil organic matter stabilization. Soil burial can store SOC at any depth. Here, we focus particularly on buried soil horizons at ? 1 m depth to highlight how much SOC exists at depths below those typically considered in SOC inventories, studies of soil organic matter dynamics, and most biogeochemical models. Understanding the mechanisms contributing to the stabilization or mobilization of SOC from deep and buried soils is important for predicting the response of soil C pools to landscape disturbance and feedbacks to climate.

Chaopricha, N. T.; Marin-Spiotta, E.

2013-12-01

183

Nitrification in Dutch heathland soils.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This thesis is the result of a study on the production of nitrate in Dutch heathland soils. Most of the heathlands are located on acid, sandy soils. Therefore , it has dealt mainly with the occurrence, nature and mechanisms of nitrification in acid soils. In the Netherlands, the production of nitrate in acid soils is a matter of great concern because it has become obvious that this process contributes to a continuous acidification of such soils that are exposed to high levels of deposition of...

Boer, W.

1989-01-01

184

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Tamai, K.

2010-01-01

185

Spatial and temporal variability of soil electrical conductivity related to soil moisture  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Soil electrical conductivity (ECa) is a soil quality indicator associated to attributes interesting to site-specific soil management such as soil moisture and texture. Soil ECa provides information that helps guide soil management decisions, so we performed spatial evaluation of soil moisture in two experimental fields in two consecutive years and modeled its influence on soil ECa. Soil ECa, moisture and clay content were evaluated by statistical, geostatistical and regression analyses. Semiv...

José Paulo Molin; Gustavo Di Chiacchio Faulin

2013-01-01

186

Soil science: The environmental challenge  

Energy Technology Data Exchange (ETDEWEB)

Soil scientists today are concerned with the effects of soil management on the total environment. Land use, type of tillage, irrigation practices, and application of pesticides and fertilizers can have far-reaching effects on soil and water quality and the content of greenhouse gases in the atmosphere. The need for research on these effects has not lessened the importance of continued research to maintain the capacity of soils for producing food and fiber. Soils must be protected against degradation by erosion, salinity, depletion of fertility, or accumulation of contaminants from various sources. Maintaining the quality of our soil, water, and air resources to meet the requirements of future generations constitutes the environmental challenge to soil scientists.

Menzel, R.G. (USDA-ARS Water Quality Laboratory, Durant, OK (USA))

1991-01-01

187

Communicating soil property variability in heterogeneous soil mapping units  

Science.gov (United States)

Soil properties and classes can change over very short distances. For the purpose of scale, clarity and field sampling density, soil maps in England and Wales commonly use mapping units which are groupings of taxonomic soil series, commonly found in association with each other in the landscape. These mixed units (Soil Associations), typically contain between 3 and 7 soil series with physical or chemical properties, which can vary across the mapping unit, or may be relatively homogeneous. The degree of variation is not constant between soil properties, for instance, pH may be relatively constant, but volumetric shrinkage potential may be highly variable. Over the past ten years, the number of users of GIS soil property maps has dramatically increased, yet the vast majority of these users do not have a soil or geoscience background. They are instead practitioners in specific industries. As a result, new techniques have been developed to communicate the variation in maps of soil properties to a non-expert audience. GIS data structures allow more flexibility in the reporting of uncertainty or variation in soil mapping units than paper-based maps. Some properties are categorical, others continuous. In England and Wales, the national and regional memberships of soil associations are available, with areal percentages of the comprising soil series being estimated for each association by a combination of expert judgment and field observations. Membership at a local scale can vary considerably from the national average. When summarizing across a whole map unit, for continuous variables, rarely is it appropriate to provide a mean value, or even a weighted average based on membership percentage of the association. Such approaches can make a nonsense of wide-ranging data. For instance a soil association comprising soil series with highly different percentages of sand, silt and clay may result in a 'loamy' mean soil texture which is not reflective of any of the comprising soils. For categorical data, the choice of the property of the spatially dominant soil series may provide the 'most likely' answer, but this may not be the most helpful answer for the end user. Additionally, when aggregating to select the dominant property or class, rather than the dominant taxonomic soil series, it is not uncommon for the 'dominant' class to change. One example of our new approach is to communicate the attributes of the soil associations on the basis of the worst-case scenario at various confidence levels, based on the percentage of the soil series of the association. As an example, when soil maps are used to help underwriters understand the vulnerability of an area to soil related subsidence, the maximum subsidence rating can be chosen from soils which comprise, for example, more than 5% or more than 30% of the soil association in question. Developing an understanding of end-user requirements allows optimization of soil datasets to suit their needs, and encourages engagement between soil scientists and industry.

Farewell, Timothy

2014-05-01

188

Soil Carbon Sequestration in India  

International Nuclear Information System (INIS)

With a large land area and diverse ecoregions, there is a considerable potential of terrestrial/soil carbon sequestration in India. Of the total land area of 329 million hectares (Mha), 297 Mha is the land area comprising 162 Mha of arable land, 69 Mha of forest and woodland, 11 Mha of permanent pasture, 8 Mha of permanent crops and 58 Mha is other land uses. The soil organic carbon (SOC) pool is estimated at 21 Pg (petagram = Pg = 1 x 1015 g billion ton) to 30-cm depth and 63 Pg to 150-cm depth. The soil inorganic carbon (SIC) pool is estimated at 196 Pg to 1-m depth. The SOC concentration in most cultivated soils is less than 5 g/kg compared with 15 to 20 g/kg in uncultivated soils. Low SOC concentration is attributed to plowing, removal of crop residue and other biosolids, and mining of soil fertility. Accelerated soil erosion by water leads to emission of 6 Tg C/y. Important strategies of soil C sequestration include restoration of degraded soils, and adoption of recommended management practices (RMPs) of agricultural and forestry soils. Potential of soil C sequestration in India is estimated at 7 to 10 Tg C/y for restoration of degraded soils and ecosystems, 5 to 7 Tg C/y for erosion control, 6 to 7 Tg C/y for adoption of RMPs on agricultural soils, and 22 to 26 Tg C/y for secondary carbonates. Thus, total potential of soil C sequestration is 39 to 49 (44± 5) Tg C/y

2004-01-01

189

Discovering the essence of soil  

Science.gov (United States)

Science, and what it can learn, is constrained by its paradigms and premises. Similarly, teaching and what topics can be addressed are constrained by the paradigms and premises of the subject matter. Modern soil science is founded on the five-factor model of Dokuchaev and Jenny. Combined with Retallack's universal definition of soil as geologic detritus affected by weathering and/or biology, modern soil science emphasizes a descriptive rather than an interpretive approach. Modern soil science however, emerged from the study of plants and the need to improve crop yields in the face of chronic and wide spread famine in Europe. In order to teach that dirt is fascinating we must first see soils in their own right, understand their behavior and expand soil science towards an interpretive approach rather than limited as a descriptive one. Following the advice of James Hutton given over two centuries ago, I look at soils from a physiological perspective. Digestive processes are mechanical and chemical weathering, the resulting constituents reformed into new soil constituents (e.g. clay and humus), translocated to different regions of the soil body to serve other physiological processes (e.g. lamellae, argillic and stone-line horizons), or eliminated as wastes (e.g. leachates and evolved gasses). Respiration is described by the ongoing and diurnal exchange of gasses between the soil and its environment. Circulatory processes are evident in soil pore space, drainage capacity and capillary capability. Reproduction of soil is evident at two different scales: the growth of clay crystals (with their capacity for mutation) and repair of disturbed areas such as result from the various pedo-perturbations. The interactions between biotic and abiotic soil components provide examples of both neurological and endocrine systems in soil physiology. Through this change in perspective, both biotic and abiotic soil processes become evident, providing insight into the possible behavior of ancient prebiotic soils. Furthermore, the physiological approach sheds light on the emergence of new soil components (e.g. spodic horizons) as ancient prebiotic soils adapt to a plethora of biotic carbon compounds. Other emergent soil properties and behaviors can be linked to the kinds, frequencies, order and intensities of various ubiquitous pedo-perturbations.

Frink, D.

2012-04-01

190

Soil salinity decreases global soil organic carbon stocks.  

Science.gov (United States)

Saline soils cover 3.1% (397 million hectare) of the total land area of the world. The stock of soil organic carbon (SOC) reflects the balance between carbon (C) inputs from plants, and losses through decomposition, leaching and erosion. Soil salinity decreases plant productivity and hence C inputs to the soil, but also microbial activity and therefore SOC decomposition rates. Using a modified Rothamsted Carbon model (RothC) with a newly introduced salinity decomposition rate modifier and a plant input modifier we estimate that, historically, world soils that are currently saline have lost an average of 3.47 tSOC ha(-1) since they became saline. With the extent of saline soils predicted to increase in the future, our modelling suggests that world soils may lose 6.8 Pg SOC due to salinity by the year 2100. Our findings suggest that current models overestimate future global SOC stocks and underestimate net CO2 emissions from the soil-plant system by not taking salinity effects into account. From the perspective of enhancing soil C stocks, however, given the lower SOC decomposition rate in saline soils, salt tolerant plants could be used to sequester C in salt-affected areas. PMID:22959898

Setia, Raj; Gottschalk, Pia; Smith, Pete; Marschner, Petra; Baldock, Jeff; Setia, Deepika; Smith, Jo

2013-11-01

191

Soil biodiversity and soil community composition determine ecosystem multifunctionality  

Science.gov (United States)

Biodiversity loss has become a global concern as evidence accumulates that it will negatively affect ecosystem services on which society depends. So far, most studies have focused on the ecological consequences of above-ground biodiversity loss; yet a large part of Earth’s biodiversity is literally hidden below ground. Whether reductions of biodiversity in soil communities below ground have consequences for the overall performance of an ecosystem remains unresolved. It is important to investigate this in view of recent observations that soil biodiversity is declining and that soil communities are changing upon land use intensification. We established soil communities differing in composition and diversity and tested their impact on eight ecosystem functions in model grassland communities. We show that soil biodiversity loss and simplification of soil community composition impair multiple ecosystem functions, including plant diversity, decomposition, nutrient retention, and nutrient cycling. The average response of all measured ecosystem functions (ecosystem multifunctionality) exhibited a strong positive linear relationship to indicators of soil biodiversity, suggesting that soil community composition is a key factor in regulating ecosystem functioning. Our results indicate that changes in soil communities and the loss of soil biodiversity threaten ecosystem multifunctionality and sustainability.

Wagg, Cameron; Bender, S. Franz; Widmer, Franco; van der Heijden, Marcel G. A.

2014-01-01

192

Soil biodiversity and soil community composition determine ecosystem multifunctionality.  

Science.gov (United States)

Biodiversity loss has become a global concern as evidence accumulates that it will negatively affect ecosystem services on which society depends. So far, most studies have focused on the ecological consequences of above-ground biodiversity loss; yet a large part of Earth's biodiversity is literally hidden below ground. Whether reductions of biodiversity in soil communities below ground have consequences for the overall performance of an ecosystem remains unresolved. It is important to investigate this in view of recent observations that soil biodiversity is declining and that soil communities are changing upon land use intensification. We established soil communities differing in composition and diversity and tested their impact on eight ecosystem functions in model grassland communities. We show that soil biodiversity loss and simplification of soil community composition impair multiple ecosystem functions, including plant diversity, decomposition, nutrient retention, and nutrient cycling. The average response of all measured ecosystem functions (ecosystem multifunctionality) exhibited a strong positive linear relationship to indicators of soil biodiversity, suggesting that soil community composition is a key factor in regulating ecosystem functioning. Our results indicate that changes in soil communities and the loss of soil biodiversity threaten ecosystem multifunctionality and sustainability. PMID:24639507

Wagg, Cameron; Bender, S Franz; Widmer, Franco; van der Heijden, Marcel G A

2014-04-01

193

Spatial variability of soil hydraulics and remotely sensed soil parameters  

Science.gov (United States)

The development of methods to correctly interpret remotely sensed information about soil moisture and soil temperature requires an understanding of water and energy flow in soil, because the signals originate from the surface, or from a shallow surface layer, but reflect processes in the entire profile. One formidable difficulty in this application of soil physics is the spatial heterogeneity of natural soils. Earlier work has suggested that the heterogeneity of soil hydraulic properties may be described by the frequency distribution of a single scale factor. The sensitivity of hydraulic and energetic processes to the variation of this scale factor is explored with a suitable numerical model. It is believed that such an analysis can help in deciding how accurately and extensively basic physical properties of field soils need to be known in order to interpret thermal or radar waveband signals. It appears that the saturated hydraulic conductivity needs to be known only to its order of magnitude, and that the required accuracy of the soil water retention function is about 0.02 volume fraction. Furthermore, the results may be helpful in deciding how the total scene or view field, as perceived through a sensor, is composed from the actual mosaic of transient soil properties, such as surface temperature or surface soil moisture. However, the latter proposition presupposes a random distribution of permanent properties, a condition that may not be met in many instances, and no solution of the problem is apparent.

Lascano, R. J.; Van Bavel, C. H. M.

1982-01-01

194

Chelant soil-washing technology for metal-contaminated soil.  

Science.gov (United States)

We demonstrate here, in a pilot-scale experiment, the feasibility of ethylenediaminetetraacetate (EDTA)based washing technology for soils contaminated with potentially toxic metals. Acid precipitation coupled to initial alkaline toxic metal removal and an electrochemical advanced oxidation process were used for average recovery of 76 +/- 2% of EDTA per batch and total recycle of water in a closed process loop. No waste water was generated; solid wastes were efficiently bitumen-stabilized before disposal. The technology embodiment, using conventional process equipment, such as a mixer for soil extraction, screen for soil/gravel separation, filter chamber presses for soil/liquid and recycled EDTA separation and soil rinsing, continuous centrifuge separator for removal of precipitated metals and electrolytic cells for process water cleansing, removed up to 72%, 25% and 66% of Pb, Zn and Cd from garden soil contaminated with up to 6960, 3797 and 32.6 mg kg(-1) of Pb, Zn and Cd, respectively, in nine 60kg soil batches. Concentrations of Pb and Zn remaining in the remediated soil and bioaccessible from the simulated human intestinal phase soil were reduced by 97% and 96% and were brought under the level of determination for Cd. In the most cost-effective operation mode, the material and energy costs of remediation amounted to 50.5 Euros ton(-1) soil and the total cost to 299 Euros ton(-1). PMID:24701937

Voglar, David; Lestan, Domen

2014-01-01

195

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

International Nuclear Information System (INIS)

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)

2004-05-01

196

Pneumatic soil removal tool  

Science.gov (United States)

A soil removal tool is provided for removing radioactive soil, rock and other debris from the bottom of an excavation, while permitting the operator to be located outside of a containment for that excavation. The tool includes a fixed jaw, secured to one end of an elongate pipe, which cooperates with a movable jaw pivotably mounted on the pipe. Movement of the movable jaw is controlled by a pneumatic cylinder mounted on the pipe. The actuator rod of the pneumatic cylinder is connected to a collar which is slidably mounted on the pipe and forms part of the pivotable mounting assembly for the movable jaw. Air is supplied to the pneumatic cylinder through a handle connected to the pipe, under the control of an actuator valve mounted on the handle, to provide movement of the movable jaw.

Neuhaus, John E. (Newport News, VA)

1992-01-01

197

Bioremediation of soils  

International Nuclear Information System (INIS)

Bioremediation of hydrocarbon contaminated soils has evolved from the refinery land treatment units of thirty years ago to the modern slurry reactors of today. Modifications in the process include engineering controls designed to prevent the migration of hydrocarbons into the unsaturated zone, the saturated zone and groundwater, and the atmosphere. Engineering innovations in the area of composting and bioaugmentation that have focused on further process control and the acceleration of the treatment process will form the basis for future improvements in bioremediation technology. Case studies for established methods that have survived this development process and continue to be used as cost effective biological treatments like engineered land farms, soil heap treatment and in situ treatment will be discussed

1991-02-06

198

Food, soil, and agriculture  

International Nuclear Information System (INIS)

The growing pressures on the world's land resources will result in problems requiring a major research effort.The first group of problems relates to increased soil degradation. The research to alleviate this will have to incorporate not only physical and biological solutions, but also pay much more attention to the socio-economic context in which the conservation programmes need to succeed.The second major area for research on land resource is to make better use of low-capacity or problem soils.This could be by reducing the existing limitations, such as changing physical or chemical characteristics of the soil, or by developing plants and production techniques which reduce the detrimental effects of constraints. Example of these are acidity, salinity, and aluminium toxicity. Finally the broadest and more important area is that of research to enable more intensive use of better-quality land. Research topics here may relate to optimal plant nutrient management, soil moisture management, and developing cultivation techniques with minimum commercial energy requirements. Making plants more productive will involve research aimed at increasing photosynthetic efficiency, nitrogen fixation, disease and pest resistance, improved weed control, and bio-engineering to adjust plant types to maximize production potentials. Improved rotational systems for the achievement of many of the above goals will become increasingly important, as the potential problems or inappropriate cultivation practices become evident. In conclusion, food supplies of the world could meet the rapidly rising demands that are made on them, if agriculture receives sufficient attention and resources. Even with most modern development, land remains the base for agriculture, and optimal use of the world's land resources is thus crucial for future agricultural production

1981-09-01

199

Soils and organic sediments  

International Nuclear Information System (INIS)

The organic component of soils is basically made up of substances of an individual nature (fats, waxes, resins, proteins, tannic substances, and many others), and humic substances (Kononova, 1966). These are complex polymers formed from breakdown products of the chemical and biological degradation of plant and animal residues. They are dark coloured, acidic, predominantly aromatic compounds ranging in molecular weight from less than one thousand to tens of thousands (Schnitzer, 1977). They can be partitioned into three main fractions:(i) Humic acid, which is soluble in dilute alkaline solution, but can be precipitated by acidification of the alkaline extract.(ii) Fulvic acid, which is soluble in alkaline solution, but is also soluble on acidification.(iii) Humin that cannot be extracted from the soil or sediment by dilute acid or alkaline solutions. It has mostly been assumed that the humic and fulvic acid components of the soil are part of the mobile, or 'active' component, and the humin component is part of the 'passive' component. Other types of organic sediments are likely to contain chemical breakdown products of plant material, plant fragments and material brought in from outside sources. The outside material can be contemporaneous with sediment deposition, can be older material, or younger material incorporated into the sediment long after deposition. Recognition of 'foreign' material is essential for dating, but is not an easy task. Examples of separation techniques for humic and non humic components are evaluated for their efficiency

1999-04-08

200

Soils and organic sediments  

Energy Technology Data Exchange (ETDEWEB)

The organic component of soils is basically made up of substances of an individual nature (fats, waxes, resins, proteins, tannic substances, and many others), and humic substances (Kononova, 1966). These are complex polymers formed from breakdown products of the chemical and biological degradation of plant and animal residues. They are dark coloured, acidic, predominantly aromatic compounds ranging in molecular weight from less than one thousand to tens of thousands (Schnitzer, 1977). They can be partitioned into three main fractions:(i) Humic acid, which is soluble in dilute alkaline solution, but can be precipitated by acidification of the alkaline extract.(ii) Fulvic acid, which is soluble in alkaline solution, but is also soluble on acidification.(iii) Humin that cannot be extracted from the soil or sediment by dilute acid or alkaline solutions. It has mostly been assumed that the humic and fulvic acid components of the soil are part of the mobile, or `active` component, and the humin component is part of the `passive` component. Other types of organic sediments are likely to contain chemical breakdown products of plant material, plant fragments and material brought in from outside sources. The outside material can be contemporaneous with sediment deposition, can be older material, or younger material incorporated into the sediment long after deposition. Recognition of `foreign` material is essential for dating, but is not an easy task. Examples of separation techniques for humic and non humic components are evaluated for their efficiency 18 refs.

Head, M.J. [University of Wollongong, Wollongong, NSW (Australia). School of Geosciences

1999-11-01

 
 
 
 
201

The impact of agricultural soil erosion on soil phosphorus cycling  

Science.gov (United States)

Soils play a key role in controlling the cycling of nutrients and carbon through the lithosphere and biosphere, yet estimates of the influence of soil on phosphorus cycling does not conventionally take into account erosion, lateral movement and soil mixing. Here, we synthesize data on the global fluxes of soil phosphorus moving over agricultural landscapes as a result of erosion processes. We demonstrate how the mobilization and deposition of soil can have significant impacts on phosphorus cycling causing lateral P similar in magnitude to those induced by fertilizer application and crop removal. This has consequences for primary productivity, which in turn influences the replacement of carbon and nitrogen. Our analysis demonstrates why soils must be viewed as dynamic systems in time and space if we are to understand their role in the phosphorus cycle.

Quinton, John; Govers, Gerard; van Oost, Kristof; Bardgett, Richard

2010-05-01

202

Soil attribute database of Russia  

Science.gov (United States)

Russia has long needed a world-level soil attribute (profile) information database which should become the basis for creating a system of monitoring of the state of soils and for developing measures for their conservation and efficient land use. A unified system of gathering and storing information on soils, which at the same time would be open for general use, is needed. The present work is devoted to problems of the concept and methodology of creating a soil geographic database (SGDB) of Russia. The structure and content of the soil attribute database, underlying which is the concept of representative soils profiles, are given. A list of classifiers for preparing data presentation formats in the SGDB on the basis of existing concepts of soil morphology and classifiers characterizing the main physicochemical properties of soils is developed. The work underlies the creation of an information resource—“Soil-Geographic Database of Russia. Project of the Dokuchaev Soil Science Society”—on the Internet at the address http://db.soi.msu.ru .

Kolesnikova, V. M.; Alyabina, I. O.; Vorob'eva, L. A.; Molchanov, E. N.; Shoba, S. A.; Rozhkov, V. A.

2010-08-01

203

Modeling biogeochemistry in agricultural soils  

Energy Technology Data Exchange (ETDEWEB)

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

Li, C.; Frolking, S.; Harriss, R. [Univ. of New Hampshire, Durham, NH (United States)

1994-09-01

204

Soil water balance scenario studies using predicted soil hydraulic parameters  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Pedotransfer functions (PTFs) have become a topic drawing increasing interest within the field of soil and environmental research because they can provide important soil physical data at relatively low cost. Few studies, however, explore which contributions PTFs can make to land-use planning, in terms of examining the expected outcome of certain changes in soil and water management practices. This paper describes three scenario studies that show some aspects of how PTFs may help improve decis...

Nemes, A.; Wo?sten, J. H. M.; Bouma, J.; Va?rallyay, G.

2006-01-01

205

A Study of Effective Soil Compaction Control of Granular Soils  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Although it is known that impact compaction tests are not appropriate for granular soils, these tests continue to be widely used. Excessive settlements frequently occur in granular soils where specified field compaction is based on Standard Proctor (ASTM D 698; AASHTO T 99) maximum dry unit weights. A laboratory test program evaluated alternative test methods for granular soil compaction control and showed that a Vibrating Hammer method (similar to British Standard BS 1377:1975, Test 14) has ...

2007-01-01

206

Effect of soil permeability on virus removal through soil columns.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Laboratory experiments were performed on four different soils, using 100 cm long columns, to determine the extent of virus movement when wastewater percolated through the soils at various hydraulic flow rates. Unchlorinated secondary sewage effluent seeded with either poliovirus type 1 (strain LSc) or echovirus type 1 (isolate V239) was continuously applied to soil columns for 3 to 4 days at constant flow rates. Water samples were extracted daily from ceramic samplers at various depths of the...

1981-01-01

207

The impact of soil tillage minimization on sandy loam soil  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The influence of different soil preparation and sowing technologies on soil physical properties and grain yield of winter wheat, spring barley and spring wheat was studied in the stationary field experiments conducted at the Lithuanian Institute of Agriculture during 2003-2006. The Endocalcari-Endohypogleyic Cambisol sandy loam soil was prepared for winter and spring cereals in different ways: 1) stubble cultivation to 10-12 cm depth, mouldboard ploughing to 21-23 cm depth and tillage with a ...

Aus?kalnis, Albinas; Feiza, Virginijus

2006-01-01

208

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

International Nuclear Information System (INIS)

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

1999-01-01

209

A soil quality index for reclaimed mine soils.  

Science.gov (United States)

The quality of soils found in mines is low if they do not receive any reclamation treatment; yet, to the authors’ knowledge, there are still no equations to evaluate the quality of metal-contaminated mine soils after the application of the most widely used reclamation treatments (planting vegetation and amending with wastes). Therefore, the purposes of the present study were 1) to propose a method for developing soil quality indexes (SQIs); 2) to develop the SQIs for 2 types of mine soils (settling pond and mine tailing) reclaimed by planting trees, amending with wastes, or both; and 3) to assess the quality of these soils under field conditions. The results obtained after the use of an SQI developed for reclaimed mine soils through the selection of an SQI with a factor analysis and the totaling of the scores of the selected variables revealed that this method is a valid tool for developing SQIs. Applying this index with reclaimed mine soils showed that the untreated sites had a very low quality and that the treatment that most improved the soils was amending with wastes (sewage sludges and paper mill residues). The authors recommend the periodic addition of sewage sludges and paper mill residues to degraded sites as they increase the quality of soils, but the effects decrease over time. PMID:23787921

Asensio, Verónica; Guala, S D; Vega, Flora A; Covelo, Emma F

2013-10-01

210

Soil Properties Database of Spanish Soils Volume III.- Extremadura  

International Nuclear Information System (INIS)

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

1998-01-01

211

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

International Nuclear Information System (INIS)

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

1998-01-01

212

Soil Properties Database of Spanish Soils Volume I.-Galicia  

International Nuclear Information System (INIS)

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

1998-01-01

213

Fuzzy Representation of Soil Erosion  

Science.gov (United States)

Fuzzy representation is a productive method to explain the natural processes so that it is near to linguistic form and it is also applicable to estimate the environmental processes in where the uncertainty in information is high. As models proposed to estimate soil erosion also have uncertainties and fuzzy inference system is more flexible in describing the relationship between soil erosion and other factor, especially in managing data and model uncertainties. in the research, it is used simplified model of revised Universal Soil Loss Equation (RUSLE) to estimate soil erosion in dry lands of Kashan area in Central Iran . Then to discover the systematic (IF-Then) rules in soil erosion process, we used inductive reasoning method to discover rules of the causing agents of erosion such as rainfall erosivity, topography factors, soil erodibility , then highly supported rules converted to fuzzy rules. It is resulted that the application of fuzzy inference system for erosion evaluation is applicable in regional level.

Komaki, Ch. B.; Kainz, W.; Alavi Panah, S. K.; Matinfar, H. R.

2009-04-01

214

Stochastic Modeling of Soil Salinity  

CERN Multimedia

A minimalist stochastic model of primary soil salinity is proposed, in which the rate of soil salinization is determined by the balance between dry and wet salt deposition and the intermittent leaching events caused by rainfall events. The long term probability density functions of salt mass and concentration are found by reducing the coupled soil moisture and salt mass balance equation to a single stochastic differential equation driven by multiplicative Poisson noise. The novel analytical solutions provide insight on the interplay of the main soil, plant and climate parameters responsible for long-term soil salinization. In particular, they show the existence of two distinct regimes, one where the mean salt mass remains nearly constant (or decreases) with increasing rainfall frequency, and another where mean salt content increases markedly with increasing rainfall frequency. As a result, relatively small reductions of rainfall in drier climates may entail dramatic shifts in long-term soil salinization trend...

Suweis, S; Van der Zee, S E A T M; Daly, E; Maritan, A; Porporato, A; 10.1029/2010GL042495

2012-01-01

215

ASPECTS REGARDING THE METHODS OF SOIL AERATION  

Directory of Open Access Journals (Sweden)

Full Text Available Aspects regarding the methods of soil aeration. Soil aeration is a process to be carried out continuously the gas exchange between soil and atmosphere. The process is done mainly by the movement of water inside and outside him. There are three major gases in the soil (nitrogen,oxygen and carbon dioxide. Soil air composition differs from that of air by higher CO2 content (0,3 to 0,5%. The air in the soil is very important for the dynamics of soil. Soil aeration is accomplished through mass flow and diffusion. In this paper the authors present these methods of soil aeration

A. UNGURA?U

2011-03-01

216

Modelling soil organic carbon concentration of mineral soils in arable lands using legacy soil data  

DEFF Research Database (Denmark)

Soil organic carbon (SOC) concentration is an essential factor in biomass production and soil functioning. SOC concentration values are often obtained by prediction but the prediction accuracy depends much on the method used. Currently, there is a lack of evidence in the soil science literature as to the advantages and shortcomings of the different commonly used prediction methods. Therefore, we compared and evaluated the merits of the median approach, analysis of covariance, mixed models and random forests in the context of prediction of SOC concentrations of mineral soils under arable management in the A-horizon. Three soil properties were used in all of the developed models: soil type, physical clay content (particle size <0.01 mm) and A-horizon thickness. We found that the mixed model predicted SOC concentrations with the smallest mean squared error (0.05%2), suggesting that a mixed-model approach is appropriate if the study design has a hierarchical structure as in our scenario. We used the Estonian National Soil Monitoring data on arable lands to predict SOC concentrations of mineral soils. Subsequently, the model with the best prediction accuracy was applied to the Estonian digital soil map for the case study area of Tartu County where the SOC predictions ranged from 0.6 to 4.8%. Our study indicates that predictions using legacy soil maps can be used in national inventories and for up-scaling estimates of carbon concentrations from county to country scales.

Suuster, E; Ritz, Christian

2012-01-01

217

Dependence of soil respiration on soil temperature and soil moisture in successional forests in Southern China  

Science.gov (United States)

The spatial and temporal variations in soil respiration and its relationship with biophysical factors in forests near the Tropic of Cancer remain highly uncertain. To contribute towards an improvement of actual estimates, soil respiration rates, soil temperature, and soil moisture were measured in three successional subtropical forests at the Dinghushan Nature Reserve (DNR) in southern China from March 2003 to February 2005. The overall objective of the present study was to analyze the temporal variations of soil respiration and its biophysical dependence in these forests. The relationships between biophysical factors and soil respiration rates were compared in successional forests to test the hypothesis that these forests responded similarly to biophysical factors. The seasonality of soil respiration coincided with the seasonal climate pattern, with high respiration rates in the hot humid season (April-September) and with low rates in the cool dry season (October-March). Soil respiration measured at these forests showed a clear increasing trend with the progressive succession. Annual mean (?? SD) soil respiration rate in the DNR forests was (9.0 ?? 4.6) Mg CO2-C/hm2per year, ranging from (6.1 ?? 3.2) Mg CO2-C/hm2per year in early successional forests to (10.7 ?? 4.9) Mg CO2-C/hm2 per year in advanced successional forests. Soil respiration was correlated with both soil temperature and moisture. The T/M model, where the two biophysical variables are driving factors, accounted for 74%-82% of soil respiration variation in DNR forests. Temperature sensitivity decreased along progressive succession stages, suggesting that advanced-successional forests have a good ability to adjust to temperature. In contrast, moisture increased with progressive succession processes. This increase is caused, in part, by abundant respirators in advanced-successional forest, where more soil moisture is needed to maintain their activities. ?? 2006 Institute of Botany, Chinese Academy of Sciences.

Tang, X. -L.; Zhou, G. -Y.; Liu, S. -G.; Zhang, D. -Q.; Liu, S. -Z.; Li, J.; Zhou, C. -Y.

2006-01-01

218

Análise espacial dos fatores da equação universal de perda de solo em área de nascentes Spatial analysis of universal soil loss equation factors of a watershed area relief  

Directory of Open Access Journals (Sweden)

Full Text Available O objetivo deste trabalho foi avaliar a perda de solo de área de nascentes da Microbacia do Córrego do Tijuco, SP. Foi utilizada a análise espacial dos fatores da equação universal da perda de solo (EUPS, em integração com análise de componentes principais e geoestatística. A perda de solo média, estimada para a área, foi de 118,5 Mg ha?1 por ano, considerada alta. Próximo à zona urbana, houve alta interação dos fatores erosividade da chuva e práticas conservacionistas, o que evidencia grande perda de solo, em razão da concentração da água proveniente da camada impermeabilizada urbana, com alta velocidade de escoamento. Nos divisores de águas, a atuação da erodibilidade foi proeminente, em contraste com o fator topográfico. Foram observadas áreas com atuação conjunta destes fatores, inclusive em locais de inclinação suave, porém com alto potencial natural de erosão. A interação das análises multivariadas e geoestatística permite a estratificação da área, identifica locais com propriedades específicas quanto à perda de solo, e espacializa os fatores do processo erosivo e suas interações ao longo do relevo.The objective of this work was to evaluate the soil loss of an area of springs in the Microbacia do Córrego do Tijuco, SP, Brazil. Spatial analysis of the universal soil loss equation (USLE factors, in integrated with principal component analysis and geostatistics, was used. The average soil loss estimated for the area was 118.5 Mg ha?1 per year, which is considered high. Near the urban zone, there was a high interaction of rainfall erosivity and conservation practices, which shows a high?soil loss, due to the concentration of water from impervious urban layer with a high?flow velocity. In the water partings, the performance of erodibility was prominent, in contrast to the topographic factor. Areas were observed with joint action of these factors, including sites with gentle slope, but with a high, natural potential of erosion. The interaction of multivariate and geostatistic analyses allows the area stratification, identifies locations with specific properties as to soil loss, and spatialises the erosion factors and their interactions along the landscape.

Daniela Popim Miqueloni

2012-09-01

219

Soil Ecosystem Management in Birdlime Utilization  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The article deals with the management of material composition of the soil ecosystem, offers the technology and the technical solution for biological, inorganic substances and pollutants dispersal, passivation of soil pollutants at the depth of the current anthropogenic illuviation of 30–60 cm, works out the device for soil application of substances by rotary inter-soil cultivation providing soil and landscape conditioning.

2012-01-01

220

Indicators for Monitoring Soil Biodiversity  

DEFF Research Database (Denmark)

The European Union (EU) soil policy is described in general terms in the EU Soil Strategy (EC 2006a) and the legally binding elements of the policy are proposed in the draft Soil Framework Directive (SFD; EC 2006b). In these documents, eight main threats to soil were identified by the EU Commission. The EU FP6 project ENVASSO (Environmental Assessment of Soil for Monitoring) had the aim to design a single, integrated and operational set of EU-wide criteria and indicators to provide the basis for a harmonised comprehensive soil and land information system for monitoring in Europe. Here, a proposal is made for a set of suitable indicators for monitoring the decline in soil biodiversity (Bispo et al. 2007). These indicators were selected both from a literature review and an inventory of national monitoring programmes. Decline in soil biodiversity was defined as the reduction of forms of life living in soils (both in terms of quantity and variety) and of related functions, causing a deterioration of one or more soil functions or ecosystem services. Whereas literature review allows the identification of about 100 possible indicators, the inventory of existing monitoring networks shows that few indicators are actually measured.   For monitoring application it was considered in ENVASSO that only three key indicators per soil stress were practical. For indicating biodiversity decline it was difficult to arrive at a small set of indicators due to the complexity of soil biota and functions. Therefore, three stringent criteria were applied: an indicator should 1) have a standardized sampling and/or measuring methodology; 2) be complementary to other indicators; and 3) be easy to interpret at both scientific and policy levels.

Bispo, A.; Cluzeau, D.

2009-01-01

 
 
 
 
221

Stochastic Modeling of Soil Salinity  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A minimalist stochastic model of primary soil salinity is proposed, in which the rate of soil salinization is determined by the balance between dry and wet salt deposition and the intermittent leaching events caused by rainfall events. The long term probability density functions of salt mass and concentration are found by reducing the coupled soil moisture and salt mass balance equation to a single stochastic differential equation driven by multiplicative Poisson noise. The ...

Suweis, S.; Rinaldo, A.; Zee, S. E. A. T. M.; Daly, E.; Maritan, A.; Porporato, A.

2012-01-01

222

Soil Erosion Issues in Agriculture  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The book deals with several aspects of soil erosion, focusing on its connection with the agricultural world. Chapters’ topics are various, ranging from irrigation practices to soil nutrient, land use changes or tillage methodologies. The book is subdivided into fourteen chapters, sorted in four sections, grouping different facets of the topic: introductive case studies, erosion management in vineyards, soil erosion issue in dry environments, and erosion control practices. Certainly, due to ...

Godone, Danilo Francesco; Stanchi, Silvia

2011-01-01

223

How Soil Organic Matter Composition Controls Hexachlorobenzene-Soil-Interactions: Adsorption Isotherms and Quantum Chemical Modelling  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Hazardous persistent organic pollutants (POPs) interact in soil with the soil organic matter (SOM) but this interaction is insufficiently understood at the molecular level. We investigated the adsorption of hexachlorobenzene (HCB) on soil samples with systematically modified SOM. These samples included the original soil, the soil modified by adding a hot water extract (HWE) fraction (soil+3 HWE and soil+6 HWE), and the pyrolyzed soil. The SOM contents increased in the order ...

Ahmed, Ashour; Leinweber, Peter; Ku?hn, Oliver

2013-01-01

224

Soil biodiversity, biological indicators and soil ecosystem services-an overview of European approaches  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Soil biota are essential for many soil processes and functions, yet there are increasing pressures on soil biodiversity and soil degradation remains a pertinent issue. The sustainable management of soils requires soil monitoring, including biological indicators, to be able to relate land use and management to soil functioning and ecosystem services. Since the 1990s, biological soil parameters have been assessed in an increasing number of field trials and monitoring programmes across Europe. T...

Pulleman, M. M.; Creamer, R.; Hamer, U.; Helder, J.; Pelosi, C.; Pe?re?s, G.; Rutgers, M.

2012-01-01

225

SOIL FACIES – A GEOGRAPHIC LOCAL-REGIONAL COMPLETING OF SOIL TAXONOMIC UNITS  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Because the soil units have a double nature, genetic and geographic (“double identity”), not completely reflected by the system of soiltaxonomy, it was proposed to complete the name of the soil taxa by some additional aspects, named regional and local soil facies. These soil facies refer to the soil differentiating features of regional and respectively local significance. The soil name according to the soil taxonomy will be completed with the names of regional andlocal soil facies, genera...

2012-01-01

226

Remote sensing in soil science  

Energy Technology Data Exchange (ETDEWEB)

This book provides coverage of remote sensing techniques and their application in soil science. The book opens with an introduction to the physical aspects of electromagnetic radiation and the technical aspects of remote sensing and image processing. This is followed by a discussion of the methods for interpreting remote sensing data, and their application to soils, vegetation, and land as a whole. As the interpretation of soil conditions is based on many aspects (i.e. soil surface, vegetation, land use, land form), reflected within the scope of the book.

Mulders, M.A.

1987-01-01

227

The Biotoxicity of Mars Soils  

Science.gov (United States)

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

Kerney, Krystal

2010-01-01

228

Urban Tree Planting: Soil 101  

Science.gov (United States)

Ever wondered how trees live amidst city sidewalks? This two-minute radio program from the show Pulse of the Planet focuses on the below-ground challenge that urban trees face--city soil. In the program, which is provided here in audio and text formats, a horticulturalist describes the importance of soil and the soil quality and quantity problems often found in cities. She then talks about a mixture that she and fellow researchers at Cornell University have developed called structural soil, which is intended to prolong urban trees' lives. Copyright 2005 Eisenhower National Clearinghouse

Planet, Pulse O.

2007-11-28

229

Soil Moisture Monitoring for Agriculture  

International Science & Technology Center (ISTC)

Elaboration of a Modern Technology for Operational Agrometeorological Soil Moisture Monitoring Spring Wheat, Yield and Disease Damage Forecasting and Recommendations for Plant Protection on the Kazakhstan Territory

230

Soil on Phoenix's TEGA  

Science.gov (United States)

This image shows soil on the doors of the Thermal and Evolved Gas Analyzer (TEGA) onboard NASA's Phoenix Mars Lander. The image was taken by the lander's Robotic Arm Camera on the 131st Martian day, or sol, of the mission (Oct. 7, 2008). This sample delivered to TEGA was named 'Rosy Red.' The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

2008-01-01

231

Desert soil collection at the JPL soil science laboratory  

Science.gov (United States)

Collection contains desert soils and other geologic materials collected from sites in the United States and foreign countries. Soils are useful for test purposes in research related to extraterrestrial life detection, sampling, harsh environmental studies, and determining suitable areas for training astronauts for lunar exploration.

Blank, G. B.; Cameron, R. E.

1969-01-01

232

Pedotransfer functions estimating soil hydraulic properties using different soil parameters  

DEFF Research Database (Denmark)

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 of the hydraulic properties of the studied soils. We found that introducing measured water content as a predictor generally gave lower errors for water retention predictions and higher errors for conductivity predictions. The best of the developed PTFs for predicting hydraulic conductivity was tested against PTFs from the literature using a subdata set of the data used in the calibration. The test showed that the developed PTFs gave better predictions (lower errors) than the PTFs from the literature. This is not surprising since the developed PTFs are based mainly on hydraulic conductivity data near saturation and sandier soils than the PTFs from the literature.

Børgesen, Christen Duus; Iversen, Bo Vangsø

2008-01-01

233

Soil fauna and soil functions: a jigsaw puzzle  

Directory of Open Access Journals (Sweden)

Full Text Available Terrestrial ecologists and soil modelers have traditionally portrayed the inhabitants of soil as a black box labeled as "soil fauna" or "decomposers or detritivores” assuming that they just merely recycle the deposited dead plant material. Soil is one of the most diverse habitats on Earth and contains one of the most diverse assemblages of living organisms; however, the opacity of this world has severely limited our understanding of their functional contributions to soil processes and to ecosystem resilience. Traditional taxonomy, based on morphological and anatomical aspects, is becoming replaced by rapid processing molecular techniques (e.g. with marker gene-based approaches. However, this may be impracticable in many ecological studies and consequently, the majority of the current knowledge, still contributes little to our understanding of their role in ecosystem functioning. Over the years, different workers have produced several ‘functional classifications’ based on the body width, feeding regime, certain behavioral and reproductive aspects and ecological niches of soil organisms. Unfortunately, the information available is severely restricted to ‘major’ groups. A better physiological and metabolic understanding of when and how a complex community of soil organisms access nutrients, alter their environment and in turn, affect soil processes, will allow a more realistic quantitative evaluation of their ecological roles in the biogeochemical cycles. Here, I review the applicability of the available approaches, highlight future research challenges and propose a dynamic conceptual framework that could improve our ability to solve this functional puzzle.

MariaJ.I.Briones

2014-04-01

234

Soil Carbon Changes Influenced by Soil Management and Calculation Method  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Throughout the years, many studies have evaluated changes in soil organic carbon (SOC) mass on a fixed-depth (FD) basis without considering changes in soil mass caused by changing bulk density (?b). This study evaluates the temporal changes in SOC caused by two factors: 1) changing SOC concentration

Mikha, Maysoon M.; Benjamin, Joseph G.; Halvorson, Ardell D.; Nielsen, David C.

2013-01-01

235

ECOLOGICAL SOIL SCREENING LEVELS FOR SOIL INVERTEBRATES AND PLANTS  

Science.gov (United States)

Ecological Soil Screening Levels (Eco-SSLs) are being developed for 24 inorganic and inorganic chemicals for soil invertebrates and plants using procedures developed by a Task Group of the USEPA Eco-SSL Work Group. The Eco-SSL Work Group is a collaboration among USEPA, DoD, DOE, ...

236

New perspectives on the soil erosion-soil quality relationship  

International Nuclear Information System (INIS)

The redistribution of soil has a profound impact on its quality (defined as its ability to function within its ecosystem and within adjacent ecosystems) and ultimately on its productivity for crop growth. The application of 137Cs-redistribution techniques to the study of erosion has yielded major new insights into the soil erosion-soil quality relationship. In highly mechanized agricultural systems, tillage erosion can be the dominant cause of soil redistribution; in other agroecosystems, wind and water erosion dominate. Each causal factor results in characteristic landscape-scale patterns of redistribution. In landscapes dominated by tillage redistribution, highest losses occur in shoulder positions (those with convex downslope curvatures); in water-erosion-dominated landscapes, highest losses occur where slope gradient and length are at a maximum. Major impacts occur through the loss of organically-enriched surface material and through the incorporation of possibly yield-limiting subsoils into the rooting zone of the soil column. The potential impact of surface soil losses and concomitant subsoil incorporation on productivity may be assessed by examining the pedological nature of the affected soils and their position in the landscape. The development of sound conservation policies requires that the soil erosion-quality relationship be rigorously examined in the full range of pedogenic environments, and future applications of the 137Cs technique hold considerable promise for providing this comprehensive global database. (author)

1998-07-01

237

Soil morphology: A key to discovering and understanding the structure and dynamics of soil covers  

International Nuclear Information System (INIS)

Full text: Professor M. Ruellan, Professor Emeritus in Pedology at AgroCampus Rennes, France, visited the SWMCN Subprogramme at IAEA Headquarters on 18 April and presented a seminar on soil morphology, a branch of soil science, studying the forms and arrangement of soil features including soil structures in each soil layer (soil horizon). His presentation reviewed the relationships between soil morphology and physical, chemical and biological processes such as soil biological activities, watershed hydrology and geochemistry, rock weathering, soil formation and erosion, human activities and climatic conditions. The sustainable use of soil resources requires the understanding of soil functions, not only in terms of their physical, chemical and biological properties but also the soil history (i.e. the evolution and functioning of soils), its interaction with nature and its position in the landscape. This understanding is necessary because the spatial diversity of soil structures within a landscape is governed by years of soil evolution and development. (author)

2008-07-01

238

Anthropogenic effects on soil micromycetes  

Directory of Open Access Journals (Sweden)

Full Text Available This paper is a synthesis of long-term investigations based on the effect of different authropogenic pollutants (mineral and organic fertilizers, heavy metals, contaminated irrigation water, nitrification inhibitor and detergents on the dynamics of soil fungi number. The investigations were performed at the Microbiology Department and trial fields of the Faculty of Agronomy in ?a?ak on smonitza and alluvium soils in field and under greenhouse conditions. Maize, wheat, barley and red clover were used as test plants in these studies. The quantitative composition of the fungi in the soils investigated was determined by the ?apek selective agar dilution method. The study results show that the number of soil fungi was dependent on the type and rate of agrochemicals used, on the growing season, and the soil zone the samples were taken from for the analysis. Lower nitrogen fertiliser rates (80 and 120 kg x ha-1 and organic fertilizers stimulated the development of soil fungi, unlike the rate of 150 kg x ha-1. Heavy metals, mercury and cadmium in particular, as well as high rates of the N-serve nitrification inhibitor, inhibited the development of this group of soil microorganisms. Generally, the adverse effect of contaminated irrigation water on the soil fungi was recorded in both soil types, and particularly in the smonitza under red clover. Low detergent (Meril concentrations did not have any significant effect on this group of microorganisms. In this respect, it can be concluded that the soil fungi number dynamics can be used in monitoring soils polluted by different toxinogenic substances.

?uki? Dragutin A.

2007-01-01

239

Thermal stability of soils and detectability of intrinsic soil features  

Science.gov (United States)

Soils are products of long term pedogenesis in ecosystems. They are characterized by a complex network of interactions between organic and inorganic constituents, which influence soil properties and functions. However, the interrelations cannot easily be determined. Our search for unifying principles of soil formation focuses on water binding. This approach was derived from water-dependent soil formation. It considers the importance of water binding in theories about the origin of genes, in the structural arrangement and functionality of proteins, and in the co-evolution of organism species and the biosphere during the history of earth. We used thermogravimetry as a primary experimental technique. It allows a simple determi-nation of bound water together with organic and inorganic components in whole soil samples without a special preparation. The primary goal was to search for fingerprinting patterns using dynamics of thermal mass losses (TML) caused by water vaporization from natural soils, as a reference base for soil changes under land use. 301 soil samples were collected in biosphere reserves, national parks and other areas as-sumingly untouched by human activity in Siberia, North and South America, Antarctica, and in several long term agricultural experiments. The results did not support the traditional data evaluation procedures used in classical differ-ential thermogravimetry. For example, peak positions and amplitudes did not provide useful information. In contrast, using thermal mass losses (TML) in prefixed smaller, e.g. 10 °C temperature intervals allowed the determination of the content of carbon, clay, nitrogen and carbonates with high accuracy. However, this approach was applicable for soils and neither for soil-like carbon containing mineral substrates without pedogenetic origin, nor for plant residues or soils containing ashes, cinder, or charcoal. Therefore, intrinsic soil regulation processes are discussed as a possible factor causing applicability of thermogravimetry for soil property determination. Despite of the extreme diversity of individual substances in soils, the thermal decay can be predicted with simple mathematical models. For example, the sum of mass losses in the large temperature interval from 100 °C to 550 °C (known from organic matter determination by ignition mass loss in past) can be predicted using TML in two small temperature intervals: 130 - 140 °C and 320 - 330 °C. In this case, the coefficient of determination between measured and calculated results reached an R2 above 0.97. Further, we found close autocorrelations between thermal mass losses in different temperature intervals. They refer to interrelations between evaporation of bound water and thermal decay of organo-mineral complexes in soils less affected by human influence. In contrast, deviations from such interrelations were found under extreme environmental conditions and in soils under human use. Those results confirm current knowledge about influence of clay on both water binding and organic matter accumulation during natural soil formation. Therefore, these interrelations between soil components are discussed as intrinsic features of soils which open the opportunity for experimental distinction of natural soils from organic and inorganic materials which do not have pedogenetic origin.

Siewert, Christian; Kucerik, Jiri

2014-05-01

240

Stool Soiling and Constipation in Children  

Science.gov (United States)

MENU Return to Web version Stool Soiling and Constipation in Children Stool Soiling and Constipation in Children What are the causes of stool ... toilet trained accidentally leak feces into their underwear. Constipation is often the cause of stool soiling. Usually, ...

 
 
 
 
241

Soil management practices for sustainable crop production  

International Nuclear Information System (INIS)

In a sustainable system, the soil is viewed as a fragile and living medium that must be protected and nurtured to ensure its long-term productivity and stability. However, due to high demand for food brought about by high population as well as the decline in agricultural lands, the soil is being exploited beyond its limit thus, leading to poor or sick soils. Sound soil management practices in the Philippines is being reviewed. The technologies, including the advantages and disadvantages are hereby presented. This includes proper cropping systems, fertilizer program, soil erosion control and correcting soil acidity. Sound soil management practices which conserve organic matter for long-term sustainability includes addition of compost, maintaining soil cover, increasing aggregates stability, soil tilt and diversity of soil microbial life. A healthy soil is a key component to sustainability as a health soil produce healthy crop plants and have optimum vigor or less susceptible to pests. (author)

2004-06-07

242

A method to detect soil carbon degradation during soil erosion  

Directory of Open Access Journals (Sweden)

Full Text Available Soil erosion has been discussed intensively but controversial both as a significant source or a significant sink of atmospheric carbon possibly explaining the gap in the global carbon budget. One of the major points of discussion has been whether or not carbon is degraded and mineralized to CO2 during detachment, transport and deposition of soil material. By combining the caesium-137 (137Cs approach (quantification of erosion rates with stable carbon isotope signatures (process indicator of mixing versus degradation of carbon pools we were able to show that degradation of carbon occurs during soil erosion processes at the investigated mountain grasslands in the central Swiss Alps (Urseren Valley, Canton Uri. Transects from upland (erosion source to wetland soils (erosion sinks of sites affected by sheet and land slide erosion were sampled. Analysis of 137Cs yielded an input of 2 and 2.6 t ha?1 yr?1 of soil material into the wetlands sites. Assuming no degradation of soil organic carbon during detachment and transport, carbon isotope signature of soil organic carbon in the wetlands could only be explained with an assumed 800 and 400 years of erosion input into the wetlands. The latter is highly unlikely with alpine peat growth rates indicating that the upper horizons might have an age between 7 and 200 years. While we do not conclude from our data that eroded soil organic carbon is generally degraded during detachment and transport, we propose this method to gain more information on process dynamics during soil erosion from oxic upland to anoxic wetland soils, sediments or water bodies.

C. Alewell

2009-06-01

243

A method to detect soil carbon degradation during soil erosion  

Directory of Open Access Journals (Sweden)

Full Text Available Soil erosion has been discussed intensively but controversial both as a significant source or a significant sink of atmospheric carbon possibly explaining the gap in the global carbon budget. One of the major points of discussion has been whether or not carbon is degraded and mineralized to CO2 during detachment, transport and deposition of soil material. By combining the caesium-137 (137Cs approach (quantification of erosion rates with stable carbon isotope signatures (process indicator of mixing versus degradation of carbon pools we were able to show that degradation of carbon occurs during soil erosion processes at the investigated mountain grasslands in the central Swiss Alps (Urseren Valley, Canton Uri. Transects from upland (erosion source to wetland soils (erosion sinks of sites affected by sheet and land slide erosion were sampled. Analysis of 137Cs yielded an input of 2 and 4.6 tha?1 yr?1 of soil material into the wetlands sites. Assuming no degradation of soil organic carbon during detachment and transport, carbon isotope signature of soil organic carbon in the wetlands could only be explained with an assumed 500–600 and 350–400 years of erosion input into the wetlands Laui and Spissen, respectively. The latter is highly unlikely with alpine peat growth rates indicating that the upper horizons might have an age between 7 and 200 years. While we do not conclude from our data that eroded soil organic carbon is generally degraded during detachment and transport, we propose this method to gain more information on process dynamics during soil erosion from oxic upland to anoxic wetland soils, sediments or water bodies.

F. Conen

2009-11-01

244

Modification of biochemical properties by soil use  

Digital Repository Infrastructure Vision for European Research (DRIVER)

[EN] Human activity is one of the main causes of the physical, chemical and biological degradation of soils. This degradation implies a change in soil quality as it involves both a decrease in productivity and changes in the ecological functions of the soil. The objective of the present study was to investigate the effect of soil use on soil biochemical properties, with the aim of providing data that allow assessment of the usefulness of enzymatic activities as indicators of soil quality. In ...

Trasar-cepeda, Carmen; Leiro?s, M. ª. Del Carmen; Gil Sotres, Fernando

2008-01-01

245

Just For Kids: Soil Biological Communities  

Science.gov (United States)

This site explains what soil is and why it is important, describes some of the organisms that live in the soil and how they interact to provide food for plants and for each other, illustrates the food cycle, and provides soil facts in different contexts. There is an Adopt a Soil Critter section and a soil quiz. Activities include coloring, collecting bugs, observing soil color and texture, and making an earthworm farm.

246

Managing soils for long-term productivity  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Meeting the goal of long-term agricultural productivity requires that soil degradation be halted and reversed. Soil fertility decline is a key factor in soil degradation and is probably the major cause of declining crop yields. There is evidence that the contribution of declining soil fertility to soil degradation has been underestimated. Sensitivity to soil degradation is implicit in the assessment of the sustainability of land management practices, with wide recognition of the fact that...

Syers, J. K.

1997-01-01

247

Brazilian Cerrado Soil Actinobacteria Ecology  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A total of 2152 Actinobacteria strains were isolated from native Cerrado (Brazilian Savannah) soils located in Passos, Luminárias, and Arcos municipalities (Minas Gerais State, Brazil). The soils were characterised for chemical and microbiological analysis. The microbial analysis led to the identification of nine genera (Streptomyces, Arthrobacter, Rhodococcus, Amycolatopsis, Microbacterium, Frankia, Leifsonia, Nakamurella, and Kitasatospora) and 92 distinct species in both seasons studied (...

Suela Silva, Monique; Naves Sales, Alenir; Teixeira Magalha?es-guedes, Karina; Ribeiro Dias, Disney; Schwan, Rosane Freitas

2013-01-01

248

Rock and Soil Anchor Systems  

Science.gov (United States)

Williams Form Engineering manufactures one of the most diverse rock and soil anchoring product lines in the world, including mechanical anchors, resin anchors, multiple corrosion protection anchors, soil nails, sledge drive anchors and self drilling anchors. The site includes not only information on the company, but also explanation of the product and their role in the mining process.

2009-05-21

249

Combining soil washing with bioremediation  

Energy Technology Data Exchange (ETDEWEB)

This paper reports on soil washing system equipment fabricated by GLIC Environmental. Applications focus on soil washing to remove hydrocarbon contaminants followed by bioremediation of wash waters to reduce the volume of materials requiring disposal. Other soil washing applications include the removal of selected metals. The EPA has identified both soil washing and bioremediation as ``innovative technologies`` in its efforts to promote alternative treatment technologies within the Superfund program. Recent EPA literature has described the merits of ``treatment trains`` where contaminated materials are treated with successive treatment methods to meet such objectives as reduction of total volume of regulated materials requiring disposal. The combination of soil washing with bioremediation is an effective ``treatment train``. Specialized soil washing equipment has been assembled utilizing the soil washing field experience in remediation of GLIC Environmental personnel together with the fabrication shop capabilities of a sister company. Typically a job has $750--900,000 worth of equipment on site, and treats more than 5,000 yd{sup 3} of contaminated soil at a rate of 250--300 yd{sup 3} in a 10-hour shift.

Moore, F.

1994-12-31

250

[soils tech transcript.doc  

…block. There you go, you can really see that now. So that soil block came out now in situ. There's no teasing apart with the spade to force the fissures. So let's just see what we've got I'm teasing this apart looking for the natural breaks in the soil. And you can see here that water's actually been…

251

[soils tech transcript.doc  

…matter. And a few other things as well like iron and calcium. But you want some glue in the soil. And the glue is clay, because clay is sticky, so it sticks things together, and also the organic matter which is sticky. A sandy soil naturally has low organic matter, and naturally has low clay content, therefore…

252

MUTATIONS IN SOIL: A REVIEW  

Science.gov (United States)

The intentional and accidental discharges of toxic pollutants into the lithosphere results in soil contamination. In some cases (e.g., wood preserving wastes, coal-tar, airborne combustion by-products) the contaminated soil constitutes a genotoxic hazard. This work is a comprehen...

253

[soils tech transcript.doc  

…structure, is two things: it's clay content and the organic matter. And a few other things as well like iron and calcium. But you want some glue in the soil. And the glue is clay, because clay is sticky, so it sticks things together, and also the organic matter which is sticky. A sandy soil naturally has…

254

The impact of soil degradation on soil functioning in Europe  

Science.gov (United States)

The European Commission has presented in September 2006 its Thematic Strategy for Soil Protection.The Thematic Strategy for Soil Protection consists of a Communication from the Commission to the other European Institutions, a proposal for a framework Directive (a European law), and an Impact Assessment. The Communication (COM(2006) 231) sets the frame. It defines the relevant soil functions for Europe and identifies the major threats. It explains why further action is needed to ensure a high level of soil protection, sets the overall objective of the Strategy and explains what kind of measures must be taken. It establishes a ten-year work program for the European Commission. The proposal for a framework Directive (COM(2006) 232) sets out common principles for protecting soils across the EU. Within this common framework, the EU Member States will be in a position to decide how best to protect soil and how use it in a sustainable way on their own territory. The Impact Assessment (SEC (2006) 1165 and SEC(2006) 620) contains an analysis of the economic, social and environmental impacts of the different options that were considered in the preparatory phase of the strategy and of the measures finally retained by the Commission. Since 2006 a large amount of new evidence has allowed to further document the extensive negative impacts of soil degradation on soil functioning in Europe. Extensive soil erosion, combined with a constant loss of soil organic carbon, have raised attention to the important role soils are playing within the climate change related processes. Other important processes are related to the loss of soil biodiversity, extensive soil sealing by housing and infrastructure, local and diffuse contamination by agricultural and industrial sources, compaction due to unsustainable agricultural practices and salinization by unsustainable irrigation practices. The extended impact assessment by the European Commission has attempted to quantify in monetary terms the actual economic impact of soil degradation in Europe.The total costs of soil degradation that could be assessed for erosion, organic matter decline, salinisation, landslides and contamination on the basis of available data, would be up to €38 billion annually for EU25. These estimates are necessarily wide ranging due to the lack of sufficient quantitative and qualitative data. Future research activities will have to address, in multidisciplinary teams, the social and economic aspects of soil degradation in Europe, in order to come up with more reliable estimates of the economic impact of soil degradation. A more reliable and updated system of indicators needs to be developed in order to cover the full cycle of the Driving forces-Pressures-State-Impact-Response (DPSIR) framework. Recent developments towards a new soil monitoring system for Europe will be presented as well as some of the recent outputs of the European Soil Data Centre (ESDAC).

Montanarella, Luca

2010-05-01

255

Microwave Remote Sensing in Soil Quality Assessment  

Science.gov (United States)

Information of spatial and temporal variations of soil quality (soil properties) is required for various purposes of sustainable agriculture development and management. Traditionally, soil quality characterization is done by in situ point soil sampling and subsequent laboratory analysis. Such methodology has limitation for assessing the spatial variability of soil quality. Various researchers in recent past showed the potential utility of hyperspectral remote sensing technique for spatial estimation of soil properties. However, limited research studies have been carried out showing the potential of microwave remote sensing data for spatial estimation of various soil properties except soil moisture. This paper reviews the status of microwave remote sensing techniques (active and passive) for spatial assessment of soil quality parameters such as soil salinity, soil erosion, soil physical properties (soil texture & hydraulic properties; drainage condition); and soil surface roughness. Past and recent research studies showed that both active and passive microwave remote sensing techniques have great potentials for assessment of these soil qualities (soil properties). However, more research studies on use of multi-frequency and full polarimetric microwave remote sensing data and modelling of interaction of multi-frequency and full polarimetric microwave remote sensing data with soil are very much needed for operational use of satellite microwave remote sensing data in soil quality assessment.

Saha, S. K.

2011-08-01

256

Extraction of soil organic phosphorus.  

Science.gov (United States)

Organic phosphorus is an important component of soil biogeochemical cycles, but must be extracted from soil prior to analysis. Here we critically review the extraction of soil organic phosphorus, including procedures for quantification, speciation, and assessment of biological availability. Quantitative extraction conventionally requires strong acids and bases, which inevitably alter chemical structure. However, a single-step procedure involving sodium hydroxide and EDTA (ethylenediaminetetraacetate) is suitable for most soils and facilitates subsequent speciation by nuclear magnetic resonance spectroscopy. Analysis of extracts by molybdate colorimetry is a potential source of error in all procedures, because organic phosphorus is overestimated in the presence of inorganic polyphosphates or complexes between inorganic phosphate and humic substances. Sequential extraction schemes fractionate organic phosphorus based on chemical solubility, but the link to potential bioavailability is misleading. Research should be directed urgently towards establishing extractable pools of soil organic phosphorus with ecological relevance. PMID:18969994

Turner, Benjamin L; Cade-Menun, Barbara J; Condron, Leo M; Newman, Susan

2005-04-15

257

Soil Erosion Threatens Food Production  

Directory of Open Access Journals (Sweden)

Full Text Available Since humans worldwide obtain more than 99.7% of their food (calories from the land and less than 0.3% from the oceans and aquatic ecosystems, preserving cropland and maintaining soil fertility should be of the highest importance to human welfare. Soil erosion is one of the most serious threats facing world food production. Each year about 10 million ha of cropland are lost due to soil erosion, thus reducing the cropland available for world food production. The loss of cropland is a serious problem because the World Health Organization and the Food and Agricultural Organization report that two-thirds of the world population is malnourished. Overall, soil is being lost from agricultural areas 10 to 40 times faster than the rate of soil formation imperiling humanity’s food security.

Michael Burgess

2013-08-01

258

Evaluation of soil washing for radiologically contaminated soils  

International Nuclear Information System (INIS)

Soil washing has been applied internationally to decontaminate soils due to the widespread increase in environmental awareness manifested in the United States by promulgation of the Comprehensive Environmental Response, Compensation and Liability Act, yet we continue to lack understanding on why the technique works in one application and not in another. A soil washing process typically integrates a variety of modules, each designed to decontaminate the matrix by destroying a particular phase or segregating a particle size fraction in which the contaminants are concentrated. The more known about how the contaminants are fixed, the more likely the process will succeed. Much can be learned from bioavailability studies on heavy metals in soils. Sequential extraction experiments designed to destroy one fixation mechanism at a time can be used to determine how contaminants are bound. This knowledge provides a technical basis for designing a processing strategy to efficiently decontaminate soil while creating a minimum of secondary wastes. In this study, a soil from the Idaho National Engineering Laboratory was physically and chemically characterized, then sequentially extracted to determine if soil washing could be effectively used to remove cesium, cobalt and chromium

1994-01-01

259

Evaluation of soil washing for radiologically contaminated soils  

Energy Technology Data Exchange (ETDEWEB)

Soil washing has been applied internationally to decontaminate soils due to the widespread increase in environmental awareness manifested in the United States by promulgation of the Comprehensive Environmental Response, Compensation and Liability Act, yet we continue to lack understanding on why the technique works in one application and not in another. A soil washing process typically integrates a variety of modules, each designed to decontaminate the matrix by destroying a particular phase or segregating a particle size fraction in which the contaminants are concentrated. The more known about how the contaminants are fixed, the more likely the process will succeed. Much can be learned from bioavailability studies on heavy metals in soils. Sequential extraction experiments designed to destroy one fixation mechanism at a time can be used to determine how contaminants are bound. This knowledge provides a technical basis for designing a processing strategy to efficiently decontaminate soil while creating a minimum of secondary wastes. In this study, a soil from the Idaho National Engineering Laboratory was physically and chemically characterized, then sequentially extracted to determine if soil washing could be effectively used to remove cesium, cobalt and chromium.

Gombert, D. II

1994-03-01

260

know Soil Know Life - Getting Kids Excited About Soils  

Science.gov (United States)

In the United States soils are often taught in primary school (grade 3-6) but with little excitement or passion. We have been working with schools and teachers to bring our passion about soils to this audience. The methods and message can be conveyed simply and effectively by engaging the students in a dialog and through kinematic learning. Our approach is to begin with a simple question - what are 4 things we cannot live without. The answer - Air, Water, Sunlight, and Soil. Most students say "food, shelter, clothing, plants, animals etc." so we then explain all of those come from soil. This leads us to a quick "dance" illustrating that without soils we would be 'Hungry. Homeless, and Naked". The results are that students and teachers remember this simple message. From this point it is our hope that students will continue to understand the importance of soils and stop treating soils like dirt. Other simple exercises for this younger audience will also be presented.

Lindbo, David L.; Robinson, Clay; Kozlowski, Deborah

2014-05-01

 
 
 
 
261

How Soil Organic Matter Composition Controls Hexachlorobenzene-Soil-Interactions: Adsorption Isotherms and Quantum Chemical Modelling  

CERN Document Server

Hazardous persistent organic pollutants (POPs) interact in soil with the soil organic matter (SOM) but this interaction is insufficiently understood at the molecular level. We investigated the adsorption of hexachlorobenzene (HCB) on soil samples with systematically modified SOM. These samples included the original soil, the soil modified by adding a hot water extract (HWE) fraction (soil+3 HWE and soil+6 HWE), and the pyrolyzed soil. The SOM contents increased in the order pyrolyzed soil < original soil < soil+3 HWE < soil+6 HWE. For the latter three samples this order was also valid for the HCB adsorption. The pyrolyzed soil adsorbed more HCB than the other samples at low initial concentrations, but at higher concentrations the HCB adsorption became weaker than in the samples with HWE addition. This adsorption behaviour combined with the differences in the chemical composition between the soil samples suggested that alkylated aromatic, phenol, and lignin monomer compounds contributed most to the HC...

Ahmed, Ashour; Kühn, Oliver

2013-01-01

262

Role of soil properties in water retention characteristics of main Hungarian soil types  

Directory of Open Access Journals (Sweden)

Full Text Available Relationship between easily available soil properties and soil water retention at given matric potentials were analysed on brown forest soils, chernozems and meadow soils of Hungarian Detailed Soil Hydrophysical Database (Hungarian acronym: MARTHA. We studied the influence of soil properties displayed on the 1:10000 scale Hungarian soil maps on soil water retention at -0.1, -33, -1500 and -150000 kPa. Continuous (particle size distribution, organic matter content, calcium carbonate content and pH and category type (ordinal: soil texture, ordinal type information on organic matter content, calcium carbonate content and pH; nominal: soil subtype classes variables were used in the analyses. The relationships was analysed with random forest method based on conditional inference trees (cforest. Water retention of different soil types was characterized. Importance of soil properties in the prediction of soil water content varies according to soil type and matric potentials.

Brigitta Toth

2014-06-01

263

A Review of Fishpond Soil Management Principles in Nigeria  

Directory of Open Access Journals (Sweden)

Full Text Available The suitability of sites for culture fisheries depends on the soil. There is therefore the need to have proper background on the nature and properties of soils. The pond oils, soil functions in fish pond, soil characterization, components and soil mineral constituents, oil profile soil classification, soil fertility, nutrients, primary and secondary nutrients, soil organic matter, common soil problems, field and laboratory methods in acid sulphate soil identification, management of acid sulphate soil conditions, lime requirements for soils, alkalinity/sodicity, salinity, excess organic matter, soil sampling and analysis are reviewed in this article to provide the needed background in soil for effective culture fisheries management and practices.

A.T. Ekubo

2011-11-01

264

Soil solid-phase controls lead activity in soil solution.  

Science.gov (United States)

Lead pollution of the environment is synonymous with civilization. It has no known biological function, and is naturally present in soil, but its presence in food crops is deemed undesirable. The concern regarding Pb is mostly due to chronic human and animal health effects, rather then phytotoxicity. However, not much is known about the chemistry and speciation of Pb in soils. We determined the activity of Pb2+, in near neutral and alkaline soils, representative of alluvial, desertic and calcareous soils of Egypt, using the competitive chelation method. Lead activity ranged from 10(-6.73) to 10(-4.83) M, and was negatively correlated with soil and soil solution pH (R2 = -0.92, P diagram for the various Pb minerals found in soil was constructed using published thermodynamic data obtained from the literature, and our measured Pb2+ activities compared with this information. The measured Pb2+ activities were undersaturated with regard to the solubility of PbSiO3 in equilibrium with SiO2 (soil). However, they were supersaturated with regard to the solubilities of the Pb carbonate minerals PbCO3 (cerussite) and Pb3(CO3)2(OH)2 in equilibrium with atmospheric CO2 and hydroxide Pb(OH)2. They were also supersaturated with regard to the solubilities of the Pb phosphate minerals Pb3(PO4)2, Pb5(PO4)3OH, and Pb4O(PO4)2 in equilibrium with tricalcium phosphate and CaCO3. The activity of Pb2+ was not regulated by any mineral of known solubility in our soils, but possibly by a mixture of Pb carbonate and phosphate minerals. PMID:11841061

Badawy, S H; Helal, M I D; Chaudri, A M; Lawlor, K; McGrath, S P

2002-01-01

265

Remote sensing of soil moisture - Recent advances  

Science.gov (United States)

Recent advancements in microwave remote sensing of soil moisture include a method for estimating the dependence of the soil dielectric constant on its texture, the use of a percent of field capacity to express soil moisture magnitudes independently of soil texture, methods of estimating soil moisture sampling depth, and models for describing the effect of surface roughness on microwave response in terms of surface height variance and horizontal correlation length, as well as the verification of radiative transfer model predictions of microwave emission from soils and methods for the estimation of vegetation effects on the microwave response to soil moisture. Such researches have demonstrated that it is possible to remotely sense soil moisture in the 0-5 cm soil surface layer, and simulation studies have indicated how remotely sensed surface soil moisture may be used to estimate evapotranspiration rates and root-zone soil moisture.

Schmugge, T. J.

1983-01-01

266

Soil mesofauna of taiga burozems  

Science.gov (United States)

In the burozems of the plains, the composition of the invertebrates and saprophages (the prevailing primary destroyers) differed from that in the mountainous soils only by the absence of millipedes of the Geophilomorpha order. At the same time, the differences in these characteristics between the burozems and soddypodzolic soils of the neighboring coniferous-broad-leaved forests were more significant: in the latter, the composition of the ecological groups of earthworms was more diverse. Among the earthworms, secondary destroyers (detritophages) consuming well-decomposed residues of plants and animals predominated: Aporrectodea caliginosa, A. rosea, and Octolasium lacteum. In the taiga burozems, among the secondary destroyers, very few O. lacteum among the earthworms, and Polyzonium germanicum among the millipede diplopods were found. Primary destroyers that only comminute plant tissues ( Dendrobaena octaedra and Dendrodrilus rubidus f. tenuis) were the main representatives in the invertebrate population of these soils. The differences also concerned the group composition and the proportion between the life forms of the earthworms. In the southern taiga burozems, only the litter ( Dendrobaena octaedra and Dendrodrilus rubidus f. tenuis) earthworms and species of the upper soil layer ( Octolasium lacteum) were present. In the mountainous burozems of the Transcarpathian region, litter inhabitants ( Dendrobaena attemsi and Aporrectodea submontana), soil-litter inhabitants ( Dendrobaena alpina—Transcarpathian region), and inhabitants of the upper ( Helodrilus cernosvitovianus) and middle ( Aporrectodea carpathica and A. sturanyi) soil layers (in the Primorskii region, only the soil-litter Eisenia nordenskioldi) were identified. In the soddy-podzolic soils, dwellers of the middle soil layers ( Aporrectodea caliginosa, A. rosea, and Lumbricus terrestris) were constantly present along with the species dwelling in the litter and in the upper soil layers (in the litter— Dendrobaena octaedra, Dendrodrilus rubidus f. tenuis, and L. castaneus; in the litter-soil layer— L. rubellus; in the upper soil layer— Octolasium lacteum). The higher diversity of the earthworm life forms in the soddy-podzolic soils points to the stronger development of their humus horizons as compared to those horizons in the burozems of the southern taiga and mountains.

Gryuntal', S. Yu.

2009-11-01

267

Root Patterns in Heterogeneous Soils  

Science.gov (United States)

Heterogeneous water availability is a typical characteristic of soils in which plant roots grow. Despite the intrinsic heterogeneity of soil-plant water relations, we know little about the ways how plants respond to local environmental quality. Furthermore, increasing use of soil amendments as partial water reservoirs in agriculture calls for a better understanding of plant response to soil heterogeneity. Neutron radiography is a non-invasive imaging that is highly sensitive to water and root distribution and that has high capability for monitoring spatial and temporal soil-plant water relations in heterogeneous systems. Maize plants were grown in 25 x 30 x 1 cm aluminum slabs filled with sandy soil. On the right side of the compartments a commercial water absorbent (Geohumus) was mixed with the soil. Geohumus was distributed with two patterns: mixed homogeneously with the soil, and arranged as 1-cm diameter aggregates (Fig. 1). Two irrigation treatments were applied: sufficient water irrigation and moderate water stress. Neutron radiography started 10 days after planting and has been performed twice a day for one week. At the end of the experiment, the containers were opened, the root were removed and dry root weight in different soil segments were measured. Neutron radiography showed root growth tendency towards Geohumus treated parts and preferential water uptake from Geohumus aggregates. Number and length of fine lateral roots were lower in treated areas compared to the non-treated zone and to control soil. Although corn plants showed an overall high proliferation towards the soil water sources, they decreased production of branches and fine root when water was more available near the main root parts. However there was 50% higher C allocation in roots grown in Geohumus compartments, as derived by the relative dry weight of root. The preferential C allocation in treated regions was higher when plants grew under water stress. We conclude that in addition to the inherent effect of water absorbent materials on increasing soil water availability, the distribution pattern of the soil amendments had an important role on root growth strategy and plant water uptake. Neutron radiography of the top, right corner of one sample. The Geohumus is arranged as aggregates.

Dara, A.; Moradi, A. B.; Carminati, A.; Oswald, S. E.

2010-12-01

268

The use of isotopes in soil fertility and soil chemistry  

International Nuclear Information System (INIS)

The concept of radioactive and enriched stable isotopes is reminded. The main topics studied with isotopes which are pointed out are the following: the isotopic exchange and its application; the E and L values; the determination of CEC; the fixing capacity of some ions by the soil particles; the measurement of the A value; the efficiency of fertilizers utilization, the interaction between nutrients, their movements through the soil, the residual effect of the fertilizers and, finally, the root system and soil organic matter. (author)

1978-01-01

269

SoilNet - A Zigbee based soil moisture sensor network  

Science.gov (United States)

Soil moisture plays a key role in partitioning water and energy fluxes, in providing moisture to the atmosphere for precipitation, and controlling the pattern of groundwater recharge. Large-scale soil moisture variability is driven by variation of precipitation and radiation in space and time. At local scales, land cover, soil conditions, and topography act to redistribute soil moisture. Despite the importance of soil moisture, it is not yet measured in an operational way, e.g. for a better prediction of hydrological and surface energy fluxes (e.g. runoff, latent heat) at larger scales and in the framework of the development of early warning systems (e.g. flood forecasting) and the management of irrigation systems. The SoilNet project aims to develop a sensor network for the near real-time monitoring of soil moisture changes at high spatial and temporal resolution on the basis of the new low-cost ZigBee radio network that operates on top of the IEEE 802.15.4 standard. The sensor network consists of soil moisture sensors attached to end devices by cables, router devices and a coordinator device. The end devices are buried in the soil and linked wirelessly with nearby aboveground router devices. This ZigBee wireless sensor network design considers channel errors, delays, packet losses, and power and topology constraints. In order to conserve battery power, a reactive routing protocol is used that determines a new route only when it is required. The sensor network is also able to react to external influences, e.g. such as rainfall occurrences. The SoilNet communicator, routing and end devices have been developed by the Forschungszentrum Juelich and will be marketed through external companies. We will present first results of experiments to verify network stability and the accuracy of the soil moisture sensors. Simultaneously, we have developed a data management and visualisation system. We tested the wireless network on a 100 by 100 meter forest plot equipped with 25 end devices each consisting of 6 vertically arranged soil moisture sensors. The next step will be the instrumentation of two small catchments (~30 ha) with a 30 m spacing of the end devices. juelich.de/icg/icg-4/index.php?index=739

Bogena, H. R.; Weuthen, A.; Rosenbaum, U.; Huisman, J. A.; Vereecken, H.

2007-12-01

270

Evaluation of soil structure in the framework of an overall soil quality rating  

DEFF Research Database (Denmark)

Soil structure is an important aspect of agricultural soil quality, and its preservation and improvement are key to sustaining soil functions. Methods of overall soil quality assessment which include visual soil structure information can be useful tools for monitoring and managing the global soil resource. The aim of the paper is: (i) to demonstrate the role of visual quantification of soil structure within the procedure of the overall soil quality assessment by the Muencheberg Soil Quality Rating (M-SQR), (ii) to quantify the magnitude and variability of soil structure and overall M-SQR on a number of agricultural research sites and (iii) to analyse the correlations of soil quality rating results with crop yields. We analysed visual soil structure and overall soil quality on a range of 20 experimental sites in seven countries. To assess visual soil structure we utilised the Visual Soil Assessment (VSA) and Visual Evaluation of Soil Structure (VESS) methods. Results showed the feasibility and reliability of both VSA and VESS methods and the overall soil quality M-SQR rating approach to give scores and classes which characterised the soil potential for cropping. The structure status of soil can be reliably assessed by these procedures. In soils with clay contents > 30% unfavourable soil structure could not be reliably recognised by measurements of the dry bulk density, but significantly by evaluation of visual soil structure. Structure scores were clearly associated with the drainage status of soil. More than 70% of the variability of crop yields at a given intensity of input may be explained by the overall M-SQR-score which includes information on soil texture, relief and climate in addition to soil structure. We conclude that methods of visual soil assessment are useful diagnostic tools for monitoring and controlling agricultural soil quality over different scales, ranging from within-fields to global. Controlling the drainage status of land and action of machinery at appropriate drainage states are pre-conditions for preserving a suitable soil structure.

Mueller, L; Shepherd, T G

2013-01-01

271

Direct soil moisture controls of future global soil carbon changes: An important source of uncertainty  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The nature of the climate–carbon cycle feedback depends critically on the response of soil carbon to climate, including changes in moisture. However, soil moisture–carbon feedback responses have not been investigated thoroughly. Uncertainty in the response of soil carbon to soil moisture changes could arise from uncertainty in the relationship between soil moisture and heterotrophic respiration. We used twelve soil moisture–respiration functions (SMRFs) with a soil carbon model (RothC) ...

Fallon, Pete; Jones, Chris D.; Ades, Melanie; Paul, Keryn

2011-01-01

272

Rock and soil rheology  

International Nuclear Information System (INIS)

The aim of the Euromech Colloquium 196 devoted to Rock and Soil Rheology is to review some of the main results obtained in the last years in this field of research and also to formulate some of the major not yet solved problems which are now under consideration. Exchange of opinions and scientific discussions are quite helpful mainly in those areas where some approaches are controversial and the progress made is quite fast. That is especially true for the rheology of geomaterials, domain of great interest for mining and petroleum engineers, engineering geology, seismology, geophysics, civil engineering, nuclear and industrial waste storage, geothermal energy storage, caverns for sports, culture, telecommunications, storage of goods and foodstuffs (cold, hot and refrigerated storages), underground oil and natural gas reservoirs etc. Some of the last obtained results are mentioned in the present volume. (orig./HP)

1985-09-10

273

Soil on Phoenix Deck  

Science.gov (United States)

This image, taken by the Surface Stereo Imager (SSI) of NASA's Phoenix Lander, shows Martian soil piled on top of the spacecraft's deck and some of its instruments. Visible in the upper-left portion of the image are several wet chemistry cells of the lander's Microscopy, Electrochemistry, and Conductivity Analyzer (MECA). The instrument on the lower right of the image is the Thermal and Evolved-Gas Analyzer. The excess sample delivered to the MECA's sample stage can be seen on the deck in the lower left portion of the image. This image was taken on Martian day, or sol, 142, on Saturday, Oct. 19, 2008. Phoenix landed on Mars' northern plains on May 25, 2008. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

2008-01-01

274

Tracing soil erosion impacts on soil organisms using 137Cs and soil nematodes  

Science.gov (United States)

The application of environmental radionuclides in soil tracing and erosion studies is now well established in geomorphology. Sediment and erosion-tracing studies are undertaken for a range of purposes in the earth sciences but until now few studies have used the technique to answer biological questions. An experiment was undertaken to measure patterns of soil loss and gain over 50 years, effectively calculating a field-scale sediment budget, to investigate soil erosion relationships between physical and biological soil components. Soil nematodes were identified as a model organism, a ubiquitous and abundant group sensitive to disturbance and thus useful indicator taxa of biological and physico-chemical changes. A field site was selected at the James Hutton Institute's experimental Balruddery Farm in NE Scotland. 10 metre-resolution topographical data was collected with differential GPS. Based on these data, a regular 30 m-resolution sampling grid was constructed in ArcGIS, and a field-sampling campaign undertaken. 104 soil cores (~50 cm-deep) were collected with a percussion corer. Radio-caesium (137Cs) activity concentrations were measured using high-purity germainum gamma-ray spectroscopy, and 137Cs areal activities derived from these values. Organic matter content by loss on ignition and grain-size distribution by laser granulometry were also measured. Additional samples were collected to characterise the soil nematode community, both for abundance and functional (trophic) composition using a combination of low-powered microscopy and molecular identification techniques (dTRFLP). Results were analysed with ArcGIS software using the Spatial Analyst package. Results show that spatial relationships between physical, chemical and biological parameters were complex and interrelated. Previous field management was found to influence these relationships. The results of this experiment highlight the role that soil erosion processes play in medium-term restructuring of the physico-chemical soil environment and the soil community.

Baxter, Craig; Rowan, John S.; McKenzie, Blair M.; Neilson, Roy

2014-05-01

275

Advancing Towards a Universal Soil Classification System  

Science.gov (United States)

Within the variability of soils across the globe, there are common soil attributes that pedologists have used to group soil within taxonomic classifications. Classification systems are necessary for the communication of information about soils. There are many national classification systems used within designated countries and two classification systems used globally, the US Soil Taxonomy and the World Reference Base. There is a great need for soil scientists to develop one common language or taxonomic system to communicate information within soil science as well as to other scientists in other disciplines. The International Union of Soil Sciences Working Group for Universal Soil Classification was officially established by an IUSS Council decision in August of 2010 at the World Congress of Soil Science in Brisbane, Australia. The charge for the Working Group includes development of common standards for methods and terminology in soil observations and investigations and the development of a universal soil classification system. The Universal Soil Classification Working Group was established and the initial meeting was held at Purdue University in West Lafayette, Indiana USA. The Working Group has evaluated the current national systems and the two international systems to identify gaps in knowledge. Currently, it was determined that gaps in knowledge exists in cold soil, hydromorphic, salt affected, anthropengic, and tropical soil groups. Additionally, several members of the Working Group have utilized taxonomic distance calculations from large databases to determine the clusters of similar taxonomic groupings utilizing the classification. Additionally, the databases are being used to make allocations into logical groups to recognize "Great Soil Groups". The great soil groups will be equivalent to great groups level from Soil Taxonomy along with similar levels in the World Reference Base, Australian Soil Classification and other defined soil classification systems. The Working Group has identified gaps in knowledge of current classification systems, utilized soil databases to determine natural clusters and identified an ideal structure for soil classicization systems.

Owens, Phillip R.; Hempel, Jon; Micheli, Erika; McBratney, Alex

2014-05-01

276

Afforestation effects on soil carbon  

DEFF Research Database (Denmark)

Understanding carbon (C) dynamics has become increasingly important due to the major role of C in global warming. Soils store the largest amount of organic C in the biosphere; therefore, changes in this compartment can have a large impact on the C storage of an ecosystem. Land-use change is a main driver of changes in soil organic carbon (SOC) pools worldwide. In Europe, afforestation (i.e. the establishment of new forest on non-forested land), is a major land-use change driven by economic and environmental interests due to its role as a C sequestration tool following the ratification of the Kyoto Protocol. Despite research efforts on the quantification of SOC stock change and soil C fluxes following this land-use change, knowledge is still scarce in regions where afforestation currently is and has been widespread, like Denmark and the rest of Northern Europe. This PhD thesis explored three main aspects of the impact of afforestation on soil C: i) changes in SOC stocks (in forest floors and mineral soils) on afforested cropland in Denmark and in afforested soils of Northern Europe; ii) changes in CH4 oxidation (uptake) potential of soils; iii) changes in soil CO2 efflux through heterotrophic respiration. In Denmark chronosequences (i.e. space-for-time substitution) of oak and Norway spruce stands at the Vestskoven site were the tool used to explore these changes. Soil OC dynamics predicted by the chronosequence approach have often been used, however they never been validated by resampling before. According to the chronosequence approach covering a time span of 40 years, topsoils (0-25 cm soil depth including forest floors) in Vestskoven are currently neither a sink nor a source for C. The more specific decadal trends at the stand level provided by repeated sampling revealed a change in source-sink C balance between soil compartments over time, with C accumulation in the mineral soil becoming increasingly important as the sink strength of forest floors decreased within 4 decades of afforestation. The chronosequence approach is an appropriate tool to assess SOC stock changes following afforestation given that assumptions of similar site conditions are met. However, repeated sampling can not only validate the chronosequence trajectories but also provide refined temporal trends. Changes in SOC in Northern Europe investigated by meta-analysis, revealed that following afforestation, significant C sequestration in soils from this region requires at least three decades or even longer time, when afforestation is performed on former agricultural soils. The faster C accretion in forest floors compensates the initial lag-phase found in mineral soils. The chronosequences also indicated that afforestation increases the CH4 sink potential of soils over time due to the gradual increase in SOC and decrease of bulk density favoring CH4-oxidation, as long as soils remain well drained. The CO2 efflux from soils may increase, due to heterotrophic respiration of a larger SOC pool and not due to higher reactivity of the SOC. However, these C sources are likely to be compensated by the C sink in the growing forest biomass.

Bárcena, Teresa G

2013-01-01

277

Agromelioration of Saline Sodic Soils  

Directory of Open Access Journals (Sweden)

Full Text Available Agromelioration is the approach for reclamation of salt-affected soils in which minimum possible quantity of chemical amendments is applied coupled with organic material/agronomic practices. A field study was conducted to reclaim saline sodic soil through the application of gypsum @ 25 % G.R. alone and in combination with FYM, rice straw, sesbania @ 10 t ha G 1 and crust scraping. A standard treatment of 100 % G.R. was also included. Rice and wheat crops were grown in rotation for two years. Crops were harvested at maturity and soil status was monitored after the harvest of each crop. The rice straw and sesbania coupled with 25 % of G.R. were found to be superior to other treatments but were comparable with 100 % G.R. as far paddy yield of first rice crop was concerned. But in the subsequent wheat, the treatment of 100 % G.R. became inferior. However, the effect of FYM improved. The other treatments where organic matter (rice straw, FYM and sesbania was applied along with 25 % G.R. became similar with 100 % G.R. at the end of 4th crop in terms of yields. The crust scrapping and gypsum @ 25 % G.R. alone were assessed as inferior techniques. Soil analysis also followed the same trends. The EC of the soil rapidly decreased due to light textured soil but the reduction in soil pH and SAR was gradual.

M. Anwar Zaka

2003-01-01

278

Estimation of soil nitrogen availability  

Directory of Open Access Journals (Sweden)

Full Text Available Our research has been made on brown forest soil that is used in long-term experiments. The soil we used had a certain crop rotation (wheat-corn and had been fertilized according to a certain system for 30 years. In the experiment, quantities of nitrogen fertilizers were gradually increased after which samples were taken from O to 30 cm depths in order to establish plant and soil parameters for assessing the applied methods. Two experiments were made: one in the field and one in a controlled environment. On grounds of the established correlation interdependence between the methods applied (the total and easily hydrolyzed nitrogen and the plant and soil parameters, in both field and pots, one can conclude that the methods of total and easily hydrolyzed nitrogen, from the standpoint of nitrogen availability in soil, are reliable. In the method of total nitrogen assessment, one should rely on the parameters regarding plants and soil in the field. In the method of easily hydrolyzed nitrogen, the parameters regarding plants and soil, in both the field and pots, are the same.

Kresovi? Mirjana M.

2003-01-01

279

The soil reference shrinkage curve  

CERN Document Server

A recently proposed model showed how a clay shrinkage curve is transformed to the soil shrinkage curve at the soil clay content higher than a critical one. The objective of the present work was to generalize this model to the soil clay content lower a critical one. I investigated (i) the reference shrinkage curve, that is, one without cracks; (ii) the superficial layer of aggregates, with changed pore structure compared with the intraaggregate matrix; and (iii) soils with sufficiently low clay content where there are large pores inside the intraaggregate clay (so-called lacunar pores). The methodology is based on detail accounting for different contributions to the soil volume and water content during shrinkage. The key point is the calculation of the lacunar pore volume variance at shrinkage. The reference shrinkage curve is determined by eight physical soil parameters: (1) oven-dried specific volume; (2) maximum swelling water content; (3) mean solid density; (4) soil clay content; (5) oven-dried structural...

Chertkov, V Y

2014-01-01

280

Salt overload: How quickly does road salt move from road to groundwater to stream in Baltimore County, MD and what are the effects on soil, groundwater, and stream chemistry?  

Science.gov (United States)

The portion of the landscape covered by roads and other impervious surfaces has increased over the last 50 years. Concurrently, application of road salt, primarily sodium chloride (NaCl), as a de-icer has increased in areas of North America with regular ice and snowfall events. Over the last 10 - 15 years, numerous investigators reported that decades of road salt application has resulted in growing concentrations of sodium and chloride in groundwater and surface water. These road salt-derived elements are present at elevated levels in the surface and groundwaters of impacted watersheds year round. An understudied aspect of road salt impacts has been the role that stormwater management basins (SMBs) play in altering the timing and location of road salt loading to urban and suburban groundwater-surface water systems. SMBs have become common in construction and development over the last 15-20 years. One of the major goals of SMBs is to decrease direct runoff from impervious surfaces to streams by redirecting that runoff into shallow groundwater and thus reducing the flashiness of streams in urban and suburban areas. An unintended consequence of SMBs is that road salt runoff from impervious surfaces is focused into the SMBs and loaded into the vadose zone and shallow groundwater in the winter and then exported to surface water throughout the year. As part of an onging project in a suburb northwest of Baltimore, MD, water samples were collected several times a year from groundwater below two SMBs, a shallow groundwater aquifer downgradient of the SMBs, and a second-order stream for which the aquifer provides baseflow. The major elemental chemistry of the samples was measured. Conductivity and water level loggers were installed to collect data in wells and surface water between grab sampling events. The logger records will be analyzed using spatio-temporal data mining techniques to extract important patterns in the data and to highlight and understand seasonal trends and storm events. A persistent groundwater plume of water with high NaCl concentrations is present below the SMBs and downgradient in the shallow groundwater aquifer. Concentrations vary seasonally with the highest concentrations in the winter and early spring. Na+ clearly interacts with the cation exchange complex (CEC) along a flowpath between the SMB and the stream. As a result, the Na:Cl ratio falls from 1:1 in groundwater below the SMBs to as low as ~1:10 and also seems to vary seasonally along the flowpath. Preliminary measurements of the CEC show that the Ca:Na ratio decreases by a factor of 2 - 5 in soil and aquifer materials affected by road salt. Preliminary strontium (Sr) isotope data indicate that groundwater and CEC within the road salt plumes are similar to Sr isotope values for seawater and are isotopically distinct from the relatively radiogenic natural weathering Sr isotope signal. Our findings indicate that SMBs increase the residence time of road salt in groundwater and stream systems with potential negative implications for ecosystems downgradient of SMBs.

Moore, J.; Sandosky, B.; McGuire, M.; Casey, R.; Snodgrass, J.; Lev, S. M.

2013-12-01

 
 
 
 
281

Soil carbon determination by thermogravimetrics  

Directory of Open Access Journals (Sweden)

Full Text Available Determination of soil constituents and structure has a vital role in agriculture generally. Methods for the determination of soil carbon have in particular gained greater currency in recent times because of the potential that soils offer in providing offsets for greenhouse gas (CO2-equivalent emissions. Ideally, soil carbon which can also be quite diverse in its makeup and origin, should be measureable by readily accessible, affordable and reliable means. Loss-on-ignition is still a widely used method being suitably simple and available but may have limitations for soil C monitoring. How can these limitations be better defined and understood where such a method is required to detect relatively small changes during soil-C building? Thermogravimetric (TGA instrumentation to measure carbonaceous components has become more interesting because of its potential to separate carbon and other components using very precise and variable heating programs. TGA related studies were undertaken to assist our understanding in the quantification of soil carbon when using methods such as loss-on-ignition. Combining instrumentation so that mass changes can be monitored by mass spectrometer ion currents has elucidated otherwise hidden features of thermal methods enabling the interpretation and evaluation of mass-loss patterns. Soil thermogravimetric work has indicated that loss-on-ignition methods are best constrained to temperatures from 200 to 430 °C for reliable determination for soil organic carbon especially where clay content is higher. In the absence of C-specific detection where mass only changes are relied upon, exceeding this temperature incurs increasing contributions from inorganic sources adding to mass losses with diminishing contributions related to organic matter. The smaller amounts of probably more recalcitrant organic matter released at the higher temperatures may represent mineral associated material and/or simply more refractory forms.

Alex B. McBratney

2013-02-01

282

Soil Stabilization: A Durability Test for Stabilized Soils.  

Science.gov (United States)

The report describes and evaluates a new testing procedure for determining the surface durability of stabilized soils by measuring the change in tensile strength at the surface of test specimens (slabs) subjected to laboratory cycles of weathering. This t...

A. E. Z. Wissa J. G. Paniagua

1969-01-01

283

Radionuclides distribution coefficient of soil to soil-solution  

International Nuclear Information System (INIS)

The present book addresses various issues related with the coefficient of radionuclides distribution between soil and soil solution. It consists of six sections and two appendices. The second section, following an introductory one, describes the definition of the coefficient and a procedures of its calculation. The third section deals with the application of the distribution coefficient to the prediction of movements of radionuclides through soil. Various methods for measuring the coefficient are described in the fourth section. The next section discusses a variety of factors (physical and chemical) that can affect the distribution coefficient. Measurements of the coefficient for different types of oils are listed in the sixth section. An appendix is attached to the book to show various models that can be helpful in applying the coefficient of distribution of radionuclides moving from soil into agricultural plants. (N.K.)

1990-01-01

284

Predicting soil to plant transfer of radiocesium using soil characteristics  

International Nuclear Information System (INIS)

A model is presented that dynamically estimates the radiocesium activity in herbage from readily available soil parameters. Three key properties underlying the bioavailability of radiocesium in soils were estimated in the model: the labile radiocesium distribution coefficient (kdl), the solution K+ concentration ([mK]), and the radiocesium concentration factor. These were determined as functions of the soil clay content and exchangeable K status. The effect of time on radiocesium fixation was described by two first-order decay equations. The model was initially parameterized using radiocesium uptake data from a ryegrass pot trial. Without further parameterization, the model was then tested for a wide range of soil and crop combinations using a database of published and unpublished information from a variety of sources and covering contamination time periods of 0.5--11 years. Model predictions of activity concentrations in crops were in generally good agreement with observed values

1999-04-15

285

Soil Data Analysis Using Classification Techniques and Soil Attribute Prediction  

Directory of Open Access Journals (Sweden)

Full Text Available Agricultural research has been profited by technical advances such as automation, data mining. Today ,data mining is used in a vast areas and many off-the-shelf data mining system products and domain specific data mining application soft wares are available, but data mining in agricultural soil datasets is a relatively a young research field. The large amounts of data that are nowadays virtually harvested along with the crops have to be analyzed and should be used to their full extent. This research aims at analysis of soil dataset using data mining techniques. It focuses on classification of soil using various algorithms available. Another important purpose is to predict untested attributes using regression technique, and implementation of automated soil sample classification.

Jay Gholap

2012-05-01

286

Predicting soil to plant transfer of radiocesium using soil characteristics  

Energy Technology Data Exchange (ETDEWEB)

A model is presented that dynamically estimates the radiocesium activity in herbage from readily available soil parameters. Three key properties underlying the bioavailability of radiocesium in soils were estimated in the model: the labile radiocesium distribution coefficient (k{sub dl}), the solution K{sup +} concentration ([m{sub K}]), and the radiocesium concentration factor. These were determined as functions of the soil clay content and exchangeable K status. The effect of time on radiocesium fixation was described by two first-order decay equations. The model was initially parameterized using radiocesium uptake data from a ryegrass pot trial. Without further parameterization, the model was then tested for a wide range of soil and crop combinations using a database of published and unpublished information from a variety of sources and covering contamination time periods of 0.5--11 years. Model predictions of activity concentrations in crops were in generally good agreement with observed values.

Absalom, J.P.; Young, S.D.; Crout, N.M.J.; Gillett, A.G. [Univ. of Nottingham, Loughborough (United Kingdom). School of Biological Sciences; Nisbet, A.F.; Woodman, R.F.M. [National Radiological Protection Board, Chilton (United Kingdom); Smolders, E. [K.U. Leuven, Heverlee (Belgium). Lab. of Soil Fertility and Soil Biology

1999-04-15

287

Soil test for some micronutrients and selenium in Egyptian soil  

International Nuclear Information System (INIS)

Several factors have simulated the need for research on the development of soil tests for micronutrients. Increased crop yield have resulted in more attention being given to the need for these elements. One of the most effective means of determining whether a particular nutrient is limiting or not is the soil test. Many studies were established in our department in order to find out the best-fit method for the most reliable estimation of some micronutrients such as: Mn, Fe, Zn and Se. Tracer technique was used as a method for determining these elements in different soils of Egypt. A review of pertinent research concerning types of extractants, the need for considering other soil properties in interpretation, and critical levels are presented

1984-01-01

288

Soil Organic Carbon dynamics in agricultural soils of Veneto Region  

Science.gov (United States)

One of the eight soil threats expressed in the European Commission's Thematic Strategy for Soil Protection (COM (2006)231 final) it's the decline in Soil Organic Matter (SOM). His preservation is recognized as with the objective to ensure that the soils of Europe remain healthy and capable of supporting human activities and ecosystems. One of the key goals of the strategy is to maintain and improve Soil Organic Carbon (SOC) levels. As climate change is identified as a common element in many of the soil threats, the European Commission (EC) intends to assess the actual contribution of the soil protection to climate change mitigation and the effects of climate change on the possible depletion of SOM. A substantial proportion of European land is occupied by agriculture, and consequently plays a crucial role in maintaining natural resources. Organic carbon preservation and sequestration in the EU's agricultural soils could have some potential to mitigate the effects of climate change, particularly linked to preventing certain land use changes and maintaining SOC stocks. The objective of this study is to assess the SOC dynamics in agricultural soils (cropland and grassland) at regional scale, focusing on changes due to land use. A sub-objective would be the evaluation of the most used land management practices and their effect on SOC content. This assessment aims to determine the geographical distribution of the potential GHG mitigation options, focusing on hot spots in the EU, where mitigation actions would be particularly efficient and is linked with the on-going work in the JRC SOIL Action. The pilot area is Veneto Region. The data available are coming from different sources, timing and involve different variables as: soil texture, climate, soil disturbance, managements and nutrients. The first source of data is the LUCAS project (Land Use/Land Cover Area Frame statistical Survey). Started in 2001, the LUCAS project aims to monitor changes in land cover/use and management of the EU territory by field observations of geo-referenced points. In 2009, a topsoil (0-30 cm) module was included to the survey and a subset of around 21,000 sites was sampled in 23 Member States. The second source is a soil survey monitoring pilot campaign carried in Veneto Region last year. The pilot campaign has been organized with the collaboration between JRC, University of Padova and ARPAV Veneto. The scope was to apply the LUCAS methodology to an experimental soil survey of 40 samples. The selection of the points to survey has been done on the basis of the LUCAS project related to Veneto Region, pedo-climatic and management unit conditions and the database on soils belonging to ARPAV Soil Unit, collected ante 2000. Data started to be investigated and permit to show changes in SOC content in a decade for different land use/cover and climatic areas. Through the bulk density data collected and the data already available from ARPAV library, it's possible to evaluate the Carbon stocks of Veneto region. Possible changes in Carbon can be related to land use changes and different strategies of management practices adopted over time.

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

2012-04-01

289

Passive microwave soil moisture research  

Science.gov (United States)

During the four years of the AgRISTARS Program, significant progress was made in quantifying the capabilities of microwave sensors for the remote sensing of soil moisture. In this paper, a discussion is provided of the results of numerous field and aircraft experiments, analysis of spacecraft data, and modeling activities which examined the various noise factors such as roughness and vegetation that affect the interpretability of microwave emission measurements. While determining that a 21-cm wavelength radiometer was the best single sensor for soil moisture research, these studies demonstrated that a multisensor approach will provide more accurate soil moisture information for a wider range of naturally occurring conditions.

Schmugge, T.; Oneill, P. E.; Wang, J. R.

1986-01-01

290

Applications of visual soil evaluation  

DEFF Research Database (Denmark)

Working Group F â??Visual Soil Examination and Evaluationâ? (VSEE) was formed over 30 years ago within the International Soil & Tillage Research Organisation (ISTRO) on the initiative of Tom Batey. The objectives of the Working Group are to stimulate interest in field methods of visual-tactile soil assessment, to encourage their wider use and to foster international cooperation. The previous main meeting of the group in 2005 at Peronne, France, brought together, for the first time, a group of soil scientists who had each developed a method to evaluate soil structure directly in the field (Boizard et al., 2006). Ten visual and tactile methods were used to assess soil structure on the same soil. This stimulated significant ongoing cooperation between participants and several authors have since modified and developed their procedures (Mueller et al., 2009 and Shepherd, 2009). Cooperation also led to the re-development of the Peerlkamp numeric method of assessment of soil structure into the Visual Evaluation of SoilStructure (VESS) spade test (Ball et al., 2007 and Guimarães et al., 2011). The meeting also recommended further cooperation between members of the Working Group. The evaluation of subsoil structure was discussed at an intermediate meeting of the group in January 2009 at Edinburgh. A common theme from the two earlier meetings was to develop both topsoil and subsoil methods to allow identification of conditions where modification of structure was required, possibly by use of a harmonized scale. Other recommendations were to include coarse textured soils, to consider controlled traffic, to relate sampling location to vegetation and crop conditions and to relate the results of visual evaluation of soil to crop performance. This latter has already been achieved with the VSA test from New Zealand which has now been extended to the assessment of environmental conditions such as potential greenhouse gas emissions, nutrient loss into groundwater and waterways and carbon sequestration (Shepherd, 2009). The meeting was held on 16thâ??18th May 2011 at Aarhus University Flakkebjerg Research Centre, Denmark. Twenty-six delegates attended from 10 countries â?? France, Denmark, Ireland, UK, New Zealand, Australia, USA, Sweden, Germany and Norway. This Special Issue of Soil and Tillage Research includes papers presented at the meeting, together with one paper related to the activity of the Working Group since the meeting in Peronne.

Ball, Bruce C; Munkholm, Lars Juhl

2013-01-01

291

Soil Erosion Threatens Food Production  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Since humans worldwide obtain more than 99.7% of their food (calories) from the land and less than 0.3% from the oceans and aquatic ecosystems, preserving cropland and maintaining soil fertility should be of the highest importance to human welfare. Soil erosion is one of the most serious threats facing world food production. Each year about 10 million ha of cropland are lost due to soil erosion, thus reducing the cropland available for world food production. The loss of cropland is a serious ...

David Pimentel; Michael Burgess

2013-01-01

292

Detection of soil compaction using soil electrical conductivity  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Conventional methods for soil compaction mapping, such as penetrometers, although accurate, work as stop-and-go providing point measurements. This process is both time consuming and labour intensive. On-the-go electrical Conductivity (EC) measurements such as electromagnetic induction (e.g. EM38) are affected by key soil properties including texture, moisture content and compaction, so offer a possible rapid alternative for compaction detection. Therefore, the aim of this work is the detectio...

Krajco, Jozef

2007-01-01

293

Soil contamination evaluations: Earthworms as indicators of soil quality  

Energy Technology Data Exchange (ETDEWEB)

Earthworms have frequently been evaluated in the field and laboratory as representatives of the soil community that are indicative of their habitat`s quality. Within a landscape or at a contaminated site, soil quality, or soil health, has become increasingly critical to cleanup-related issues that revolve around questions of ``how clean is clean`` and the bioaccumulation of soil contaminants. Through an overview of numerous field and laboratory studies, the role that earthworms have played in evaluating soil contamination will be reviewed with a particular focus on evaluations of the bioaccumulation potential of chemicals in soil. Within ecological contexts, earthworms can provide information regarding immediately observable adverse affects related, for example, to acute toxicity. Additionally, earthworms can provide information directly related to the bioaccumulation potential of a chemical and trophic transfer of environmental chemicals, especially through the food-chain. Within the decision-making process, soil contamination evaluations must consider future land-use, as well as current and future expressions of adverse biological and ecological effects under field conditions, potentially following remediation. Through integrated field and laboratory studies using earthworms, the authors have been able to identify adversely affected soil communities and have been able to provide information for assessing adverse ecological effects potentially caused by contaminants. Field surveys and on-site or in situ biological testing with earthworms, however, can not alone identify causes of effects. As such, standardized biological tests have been routinely completed in the laboratory so linkages between expression of effects and contaminants could be more readily addressed in conjunction with appropriate chemical data from the field.

Linder, G.; Wilbom, D. [HeronWorks Farm, Brooks, OR (United States)

1995-12-31

294

Soil CO2 Dynamics in a Tree Island Soil of the Pantanal: The Role of Soil Water Potential  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The Pantanal is a biodiversity hotspot comprised of a mosaic of landforms that differ in vegetative assemblages and flooding dynamics. Tree islands provide refuge for terrestrial fauna during the flooding period and are particularly important to the regional ecosystem structure. Little soil CO2 research has been conducted in this region. We evaluated soil CO2 dynamics in relation to primary controlling environmental parameters (soil temperature and soil water). Soil respiration was computed u...

Johnson, Mark S.; Couto, Eduardo Guimara?es; Pinto Jr, Osvaldo B.; Milesi, Juliana; Santos Amorim, Ricardo S.; Messias, Indira A. M.; Biudes, Marcelo Sacardi

2013-01-01

295

The use of some soil aggregate indices to assess potential soil loss in soils of south-eastern nigeria  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Six aggregate indices and some soil properties were evaluated to predict potential soil loss in soils of Southeastern Nigeria. Of the aggregate indices tested, dispersion ratio (DR), Wischmeier's erodibility index (K), clay dispersion index (CDI) and clay floccula-tion index (CFI) ranked higher than geometric mean diameter (GMD) and mean-weight diameter (MWD) in predicting potential soil loss. Some aggregate indices found to correlate well with soil loss are in order of decreasing predictabil...

Ca, Igwe; Akamigbo, F. O. R.; Mbagwu, J. S. C.

1995-01-01

296

Soil acidification in forest and organic soils in Alberta  

Energy Technology Data Exchange (ETDEWEB)

The Terrestrial Environmental Effects Monitoring Committee (TEEM) of the Wood Buffalo Environmental Association (WBEA) is jointly funded by all oil sand industries in northern Alberta to monitor the environmental impacts associated with oil sand mining in the Athabasca deposit. Soil acidification is among the environmental effects that are monitored. TEEM represents industry, government, regional communities, First Nations and non-governmental environmental stakeholders. The program is based on 15 permanent monitoring stations located across the acidifying deposition gradient from near the emission sources to about 120 km from the emission sources. Ten passive dry deposition monitors, 1 wet deposition monitor and dispersion modeling are used to estimate the acidic deposition at these sites. Sampling and assessment of the sites is conducted at 6 year intervals, beginning in 1998. Sampling and assessment near the emission sources is conducted at 3 year intervals. The assessment of vegetation performance included radial and height growth of trees, biodiversity and percent cover of forest floor vegetation. The assessment of soil chemistry included soil stratification by depth and by zone in relation to trees. Soil samples were analyzed for base saturation, base cation:aluminium, base cations, nitrogen and sulphur. No soil chemistry gradient corresponding to the acidic deposition gradient was observed in 1998. Once the data for 2004 becomes available, it will be compared with soil chemistry data from 1998 to find evidence of change related to the deposition gradient. The monitoring program is an fundamental part of acidifying emissions management in the region.

Pauls, R.

2005-07-01

297

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

Science.gov (United States)

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. Regarding soil properties, the analysis shows that organic matter from soils under minimum tillage or no-till is strongly related with runoff, the amount of sediments in runoff and soil loss. In soils from olive groves, the amount of sediments in runoff was significantly related to soil pH. Moreover, for olive-cropped soils under conventional tillage, soil loss is strongly related with clayey texture, which is characteristic of these soils. Concerning this, the relationship between soil loss and coarse sand contents is highly significant, and shows that medium-sized soil particles are most prone to detachment and transport by runoff. Thus, the average content of these fractions in soils under conventional management is more than two times that from olive groves under minimal or no tillage, which are more coarsely textured. In fine-textured soils, hydraulic conductivity is reduced, thus increasing soil erosion risk. In addition, in sandy and silty soils with low clay content, infiltration rates are high even when soil sealing is observed. At the scale of this experiment, runoff generation and soil erosion risk decrease significantly in areas under natural vegetation, with lower clay contents

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

2013-04-01

298

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

Directory of Open Access Journals (Sweden)

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.

K. Tamai

2010-03-01

299

Manipulation of soil biota in ecological research  

Directory of Open Access Journals (Sweden)

Full Text Available Manipulation of soil biota, such as soil sterilization, may have complex effects as they alter soil properties as well as microorganism communities. To assess the effects of such manipulation, we conducted an experiment using three sterilizing approaches, two soil types, and two plant species to identify the problems that may occur when different sterilizing approaches are used. The sterilizing treatments decreased growth of plants and resulted in large changes in soil nutrients and pH. Such effects varied with the approach followed. Our data suggest that studied effects on soil biota may be misleading if we fail to consider such changes in the soil.

W.-M. He

2009-12-01

300

Soil quality assessment using fuzzy modeling  

Directory of Open Access Journals (Sweden)

Full Text Available Maintaining soil productivity is essential if agriculture production systems are to be sustainable, thus soil quality is an essential issue. However, there is a paucity of tools for measurement for the purpose of understanding changes in soil quality. Here the possibility of using fuzzy modeling theory as a means to address the problem of soil quality assessment is considered. For soil quality assessment, two general types of fuzzy soil quality indicators potentially could be defined. The theoretical consideration of this process is illustrated with an example. Results indicate that the fuzzy multi-attributive approach could be effectively utilized as a tool leading to better understanding soil quality.

D. Kurtener

2008-12-01

 
 
 
 
301

Worldwide organic soil carbon and nitrogen data  

Energy Technology Data Exchange (ETDEWEB)

The objective of the research presented in this package was to identify data that could be used to estimate the size of the soil organic carbon pool under relatively undisturbed soil conditions. A subset of the data can be used to estimate amounts of soil carbon storage at equilibrium with natural soil-forming factors. The magnitude of soil properties so defined is a resulting nonequilibrium values for carbon storage. Variation in these values is due to differences in local and geographic soil-forming factors. Therefore, information is included on location, soil nitrogen content, climate, and vegetation along with carbon density and variation.

Zinke, P.J.; Stangenberger, A.G. [Univ. of California, Berkeley, CA (United States). Dept. of Forestry and Resource Management; Post, W.M.; Emanual, W.R.; Olson, J.S. [Oak Ridge National Lab., TN (United States)

1986-09-01

302

Stocks of organic carbon in Estonian soils  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The soil organic carbon (SOC) stocks (Mg ha–1) ofautomorphic mineral (9 soil groups), hydromorphic mineral (7), and lowland organic soils (4) are given for the soil cover or solum layer as a whole and also for its epipedon (topsoil) layer. The SOC stocks for forest, arable lands, and grasslands and for the entire Estonian soil cover were calculated on the basis of the mean SOC stock and distribution area of the respective soil type. In the Estonian soil cover (42 400 km2), a total of 593.8 ...

2009-01-01

303

Impact of soil properties on selected pharmaceuticals adsorption in soils  

Science.gov (United States)

The presence of human and veterinary pharmaceuticals in the environment has been recognized as a potential threat. Pharmaceuticals may contaminate soils and consequently surface and groundwater. Study was therefore focused on the evaluation of selected pharmaceuticals adsorption in soils, as one of the parameters, which are necessary to know when assessing contaminant transport in soils. The goals of this study were: (1) to select representative soils of the Czech Republic and to measure soil physical and chemical properties; (2) to measure adsorption isotherms of selected pharmaceuticals; (3) to evaluate impact of soil properties on pharmaceutical adsorptions and to propose pedotransfer rules for estimating adsorption coefficients from the measured soil properties. Batch sorption tests were performed for 6 selected pharmaceuticals (beta blockers Atenolol and Metoprolol, anticonvulsant Carbamazepin, and antibiotics Clarithromycin, Trimetoprim and Sulfamethoxazol) and 13 representative soils (soil samples from surface horizons of 11 different soil types and 2 substrates). The Freundlich equations were used to describe adsorption isotherms. The simple correlations between measured physical and chemical soil properties (soil particle density, soil texture, oxidable organic carbon content, CaCO3 content, pH_H2O, pH_KCl, exchangeable acidity, cation exchange capacity, hydrolytic acidity, basic cation saturation, sorption complex saturation, salinity), and the Freundlich adsorption coefficients were assessed using Pearson correlation coefficient. Then multiple-linear regressions were applied to predict the Freundlich adsorption coefficients from measured soil properties. The largest adsorption was measured for Clarithromycin (average value of 227.1) and decreased as follows: Trimetoprim (22.5), Metoprolol (9.0), Atenolol (6.6), Carbamazepin (2.7), Sulfamethoxazol (1.9). Absorption coefficients for Atenolol and Metoprolol closely correlated (R=0.85), and both were also related to absorption coefficients of Carbamazepin (R=0.67 and 0.68). Positive correlation was found between Trimetoprim absorption coefficients and Atenolol, Metoprolol or Carbamazepin absorption coefficients. The negative relationship was found between absorption coefficients of Sulfomethoxazol and Clarithromycin (R=-0.80). Sulfamethoxazol absorption coefficient was negatively related to pH_H2O, pH_KCL or sorption complex saturation and positively to the hydrolytic acidity or exchangeable acidity. Trimetoprim absorption coefficient was positively related to the oxidable organic carbon content, cation exchange capacity, basic cation saturation or silt content and negatively to particle density or sand content. Clarithromycin absorption coefficient was positively related to pH_H2O, pH_KCL, CaCO3 content, basic cation saturation or sorption complex saturation and negatively to hydrolytic acidity or exchangeable acidity. Atenolol and Metoprolol absorption coefficients were positively related to the oxidable organic carbon content, cation exchange capacity, basic cation saturation, salinity, clay content or silt content, and negatively to the particle density or sand content. Finally Carbamazepin absorption coefficient was positively related to the oxidable organic carbon content, cation exchange capacity or basic cation saturation, and negatively to the particle density or sand content. Evaluated pedotransfer rules for different pharmaceuticals included different sets of soil properties. Absorption coefficients could be predicted from: the hydrolytic acidity (Sulfamethoxazol), the oxidable organic carbon content (Trimetoprim and Carbamazepin), the oxidable organic carbon content, hydrolytic acidity and cation exchange capacity (Clarithromycin), the basic cation saturation (Atenolol and Metoprolol). Acknowledgement: Authors acknowledge the financial support of the Czech Science Foundation (Project No. 13-12477S).

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

2014-05-01

304

Crusting susceptibility in some allic Colombian soils  

International Nuclear Information System (INIS)

Many lab methods were used: dry and water soil aggregates stability, instability index and erosion index and their results were related with soil characteristics like texture, Fe and Al oxides and organic matter. Soil samples collected within 0-2.5 and 2.5-5 cm of the soil surface came from terrains with many kinds of both forest and savanna intervened systems. Those results were analyzed like a completely randomized designed. It was found that significative changes in oxides content could increase soil-crusting susceptibility unless soil humus was up to was up to 4%. In this sense, pastures or its rotation with rice and leguminous offer a best alternative for intervening these natural systems. Intensive land husbandry or monocultures with low stubble soil incorporation caused an increase in physical instability at the top of soil. Dry soil stability test and instability index were most adequate for these soils

2001-12-01

305

Soil decontamination and radiation monitoring  

International Nuclear Information System (INIS)

Mechanism of Cs adsorption in soils is presented. The present status of contaminated farmlands in Fukushima, Japan, from the meltdown Nuclear Power Plants is explained. To promote remediation of the contaminated farmlands, the authors propose to continuously monitor air dose at point referred to as hotspots in rural areas and radiation dose in soils by using field monitoring system (FMS) with a waterproof radiation sensor. The outline of an FMS, a useful tool for remediation of the radionuclide contaminated farmland, is explained. It consists of three components: a field router, data logger, and soil/meteorological sensors including a radiation sensor whose function is to collect data from the data logger and then send to the data server over the internet, and the data logger stores the data. The system for real time data collection from remote agricultural fields is now installed in situ soil monitoring in Iidate village, Fukushima. (S. Ohno)

2013-08-01

306

Soil sample for balloon flight  

Science.gov (United States)

... purpose of the proposed activity? The purpose of the activity is to acquire the soil sample required ... there are no activities at the chosen site. 12. Is the proposed activity expected to adversely ...

307

Extraction of silicones from soil  

Energy Technology Data Exchange (ETDEWEB)

Silicone polymer, polydimethylsiloxane (PDMS), was extracted from soil incubated at 100 mg kg[sup [minus]1] for 0,1,3,7,14, and 28 d with mean recovery of 95.4% ([sigma] = 2.1%). From four agricultural soils incubated for one week at 1, 10, and 100 mg kg[sup [minus]1], mean extraction recovery was 95.6% ([sigma] = 3.2%). The method is now being used in [sup 14]C studies on the fate of silicones in the soil environment and will later be used for extraction of silicones from field samples. Silicone polymers have a variety of uses, including lubricants, electrical insulators, and texturizers in personal care products. They can enter the environment through wastewater treatment systems in which they adsorb to the solids, and are then applied to the soil during disposal of the sludge.

Lehmann, R.G. (Dow Corning Corp., Midland, MI (United States). Health and Environmental Sciences)

1993-10-01

308

Fluorescence signature oils and soils  

Energy Technology Data Exchange (ETDEWEB)

Fluorescence analysis of soil samples proved effective in predicting the outcome of wildcats in the Geochemical Evaluation Research Team (GERT) effort. Fluorescence spectra from 255 to 530 nm from produced oils match soil analysis to a high degree. A good coincidence exists between source rocks and surface samples, as well. If the oils in a multipay prospect are distinct enough, one can estimate which oil is trapped and fingerprinting in surface samples.

Calhoun, G. (Consulting Geologist, Midland, TX (United States))

1992-04-01

309

[soils tech transcript.doc  

…to see if there are any underground cables. What I'm going to show you here. I'm just going to put the spade in here and pull this back gently and what we'll look at is the state of the soil surface. And you see how that's cracking on the surface and you see how the soil is capped, and by that I mean…

310

Opportunity Egress Aid Contacts Soil  

Science.gov (United States)

This image from the navigation camera on the Mars Exploration Rover Opportunity shows the rover's egress aid touching the martian soil at Meridiani Planum, Mars. The image was taken after the rear lander petal hyperextended in a manuever to tilt the lander forward. The maneuver pushed the front edge lower, placing the tips of the egress aids in the soil. The rover will drive straight ahead to exit the lander.

2004-01-01

311

Elementary soil and water engineering  

Energy Technology Data Exchange (ETDEWEB)

Between 1967-1975 the Northwest lost 325 acres per day of prime farmland, the Midwest (our nation's bread basket) 493 acres, and the Southwest 548 acres per day. We lost one million acres like this each year, three million for all rural land. Six problems affect our diminishing soil and water resources: erosion, drainage, irrigation, conservation of soil moisture, efficiency of water storage, floods. The first five problems are discussed in this book.

Schwab, G.O.; Frevert, R.K.

1985-01-01

312

Anthropogenic effects on soil micromycetes  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper is a synthesis of long-term investigations based on the effect of different authropogenic pollutants (mineral and organic fertilizers, heavy metals, contaminated irrigation water, nitrification inhibitor and detergents) on the dynamics of soil fungi number. The investigations were performed at the Microbiology Department and trial fields of the Faculty of Agronomy in ?a?ak on smonitza and alluvium soils in field and under greenhouse conditions. Maize, wheat, barley and red clover...

2007-01-01

313

Microbiological research of soil bioremediation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Bioremediation is the application of biological processes for the clean up of pollutants present in the environment. The scope of the review encompasses the following subjects: biodegradation of various polymeric and natural origin compounds; the applications of microorganisms to laboratory scale and field scale soil bioremediation, with a focus on petroleum hydrocarbons; bioaugmentation and characterization of microbial communities; the factors affecting soil bioremediation processes includi...

2009-01-01

314

Saline waters and soil quality  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The processes of secondary salinization due to anthropic actions are considered one of the most important environmental emergencies owing to their level of dangerousness. The soils of the dry areas of the Mediterranean basin are particularly prone to these processes. In such environments, it is imperative to resort to irrigation that allow for the reduction of risks due to soil moisture deficit and for the stabilization of yields. Frequently, saline waters are used that cause a lowering of th...

Carmelo Dazzi

2011-01-01

315

Saline waters and soil quality  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The processes of secondary salinization due to anthropic actions are considered one of the most important environmental emergencies owing to their level of dangerousness. The soils of the dry areas of the Mediterranean basin are particularly prone to these processes. In such environments, it is imperative to resort to irrigation that allow for the reduction of risks due to soil moisture deficit and for the stabilization of yields. Frequently, saline waters are used that cause a lowering of th...

Carmelo Dazzi

2006-01-01

316

Agriculture Canada Central Saskatchewan Vector Soils Data  

Science.gov (United States)

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

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

2000-01-01

317

Tropical Volcanic Soils From Flores Island, Indonesia  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Soils that are developed intropical region with volcanic parent materials have many unique properties, and high potential for agricultural use.The purpose of this study is to characterize the soils developed on volcanic materials from Flores Island, Indonesia,and to examine if the soils meet the requirements for andic soil properties. Selected five soils profiles developed fromandesitic volcanic materials from Flores Island were studied to determine their properties. They were compared inthei...

2010-01-01

318

Manipulation of soil biota in ecological research  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Manipulation of soil biota, such as soil sterilization, may have complex effects as they alter soil properties as well as microorganism communities. To assess the effects of such manipulation, we conducted an experiment using three sterilizing approaches, two soil types, and two plant species to identify the problems that may occur when different sterilizing approaches are used. The sterilizing treatments decreased growth of plants and resulted in large changes in soil nutrients and pH. Such ...

-m He, W.; -g Cui, Q.

2009-01-01

319

Diffusion coefficient of 137Cs in soil  

International Nuclear Information System (INIS)

In this paper we have studied, experimentally and theoretically, vertical distribution of 137Cs in uncultivated soil [1]. The results of 137Cs measurements in the soil of surroundings of Kragujevac are given. The samples of soil are taken from seven locations, chosen to investigate different types of soil. After the proper preparation, the measuring of activity of the samples is done with gamma- spectroscopy. Experimentally, we have determined the diffusion coefficient for different types of the soil. (author)

2003-10-01

320

Stabilization and Improvement of Organic Soils  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Peats and organic soils in general pose significant problems to geotechnical engineers due to their low strength, high compressibility and elevated creep. The research performed addressed one soil improving technique, deep soil mixing, that has been widely used for treating soft clays, but that especially in the US has found limited use in presence of organic soils. The work performed made use primarily of one soil sampled on Lindberg Road (LR) in West Lafayette, IN characterized by LOI= 45-5...

2005-01-01

 
 
 
 
321

RESISTANCE OF THE TOXAPHENE INSECTICIDE IN SOIL  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Introduction. Toxaphene is resistant to degration and has been known as persistent bioaccumulator. In oder to understand the persistence and degradation phenomena of toxaphene in soil a series of tests were run. Methods. All experiments for dry and moist soil were conducted with 10 to 20 kg soil samples, contained in plastic tubs. The experiment was carried out in two parts. The five samples studied in each part are described below. Part I: "Dry samples". Soil control I soil amended with...

Mirsattari, G.

2001-01-01

322

Soil Ecosystem Management in Birdlime Utilization  

Directory of Open Access Journals (Sweden)

Full Text Available The article deals with the management of material composition of the soil ecosystem, offers the technology and the technical solution for biological, inorganic substances and pollutants dispersal, passivation of soil pollutants at the depth of the current anthropogenic illuviation of 30–60 cm, works out the device for soil application of substances by rotary inter-soil cultivation providing soil and landscape conditioning.

Mohammed A. Bazgiev

2012-07-01

323

Impacts of soil structure on crop growth  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Intensive agricultural utilisation of soils may change the structural status and through it the credibility and fertility of soils. Since soil structure has not been quantified explicitly, studying structure-related soil phenomena is still actual. The goal of the present study was to apply field measurements on structure related soil hydrophysical properties and to study their mutual effect on crop growth. Near hydraulic water conductivity, bulk density, water retention characteristics of soi...

Rajkai K.; Végh K.R.; Várallyay G.; Farkas C.S.

1997-01-01

324

GYPSEOUS SOIL IMPROAVEMENT USING FUEL OIL  

Directory of Open Access Journals (Sweden)

Full Text Available This research investigates the suitability of fuel oil in improving gypseous soil. A detailed laboratory tests were carried-out on two soils (soil I with 51.6% gypsum content, and soil II with 26.55%, where the two soils were obtained from Al-Therthar site (Al-Anbar Province-Iraq. This study examines the improvement of soil properties using the gypsum material is locally available and low cost to minimize the effect of moisture on these soils by using the fuel oil. Study was conducted on two models of the soil gypsum, from the Tharthar area. The first model was sandy and slimy contents of Gypsym (51.6% and the second is clayey soil and the content of Gypsym is (26.55%. The program included tests measuring the permeability of soil and compressibility and their collapse properties. Have been found bearing shear strength of the soil and the amount of weight loss of fuel oil and the recession in the soil as a result of drying temperature (50oC in addition to testing category. These tests have been conducted on the treated soil and untreated to observe the effect of soil treatment on the engineering properties when mixed with varying degrees of fuel oil with the equivalent of the water content. The results showed that fuel oil is a good article to modify the soil gypsum, in order to have improved the basic properties of the soil gypsum of collapsibility and permeability, which is one of the fundamental problems of the soil gypsum and retained soil by an appropriate amount of the durability of storytelling gives durable and bearing capacity for the soil enough to carry the weight of construction and access to sustainability of these soils are suitable for use is permitted in areas exposed to moisture.

Aziz Hussein Yousif

2011-07-01

325

Davis Soil Moisture and Temperature Station Protocol  

Science.gov (United States)

The purpose of this resource is to log soil data using a Davis soil moisture and temperature station. Soil moisture and temperature sensors are installed at multiple depths and a station is set up to measure and record measurements at 15 minute intervals. These measurements are transferred to your school.s computer and then submitted to GLOBE via email data entry. Gravimetric soil moisture measurements must be taken to develop calibration curves for the soil moisture sensors.

The GLOBE Program, University Corporation for Atmospheric Research (UCAR)

2003-08-01

326

Optimal Soil Management and Environmental Policy  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper studies the effects of environmental policy on the farmer?s soil optimal management. We consider a dynamic economic model of soil erosion where the intensity use of inputs allows the farmer to control soil losses. Therefore, inputs use induces a pollution which is accentuated by the soil fragility. We show, at the steady state, that the environmental tax induces a more conservative farmer behavior for soil, but in some cases it can exacerbate pollution. These effects can be mo...

Lafforgue, Gilles; Oueslati, Walid

2005-01-01

327

Bioremediation of petroleum contaminated soil  

International Nuclear Information System (INIS)

This paper reports on bioremediation, which offers a cost-competitive, effective remediation alternative for soil contaminated with petroleum products. These technologies involve using microorganisms to biologically degrade organic constituents in contaminated soil. All bioremediation applications must mitigate various environmental rate limiting factors so that the biodegradation rates for petroleum hydrocarbons are optimized in field-relevant situations. Traditional bioremediation applications include landfarming, bioreactors, and composting. A more recent bioremediation application that has proven successful involves excavation of contaminated soil. The process involves the placement of the soils into a powerscreen, where it is screened to remove rocks and larger debris. The screened soil is then conveyed to a ribbon blender, where it is mixed in batch with nutrient solution containing nitrogen, phosphorus, water, and surfactants. Each mixed soil batch is then placed in a curing pile, where it remains undisturbed for the remainder of the treatment process, during which time biodegradation by naturally occurring microorganisms, utilizing biochemical pathways mediated by enzymes, will occur

1992-09-21

328

Soil hydrologic characterization for modeling large scale soil remediation protocols  

Science.gov (United States)

In Campania Region (Italy), the Ministry of Environment identified a National Interest Priority Sites (NIPS) with a surface of about 200,000 ha, characterized by different levels and sources of pollution. This area, called Litorale Domitio-Agro Aversano includes some polluted agricultural land, belonging to more than 61 municipalities in the Naples and Caserta provinces. In this area, a high level spotted soil contamination is moreover due to the legal and outlaw industrial and municipal wastes dumping, with hazardous consequences also on the quality of the water table. The EU-Life+ project ECOREMED (Implementation of eco-compatible protocols for agricultural soil remediation in Litorale Domizio-Agro Aversano NIPS) has the major aim of defining an operating protocol for agriculture-based bioremediation of contaminated agricultural soils, also including the use of crops extracting pollutants to be used as biomasses for renewable energy production. In the framework of this project, soil hydrologic characterization plays a key role and modeling water flow and solute transport has two main challenging points on which we focus on. A first question is related to the fate of contaminants infiltrated from stormwater runoff and the potential for groundwater contamination. Another question is the quantification of fluxes and spatial extent of root water uptake by the plant species employed to extract pollutants in the uppermost soil horizons. Given the high variability of spatial distribution of pollutants, we use soil characterization at different scales, from field scale when facing root water uptake process, to regional scale when simulating interaction between soil hydrology and groundwater fluxes.

Romano, Nunzio; Palladino, Mario; Di Fiore, Paola; Sica, Benedetto; Speranza, Giuseppe

2014-05-01

329

Soil Carbon Changes Influenced by Soil Management and Calculation Method  

Directory of Open Access Journals (Sweden)

Full Text Available Throughout the years, many studies have evaluated changes in soil organic carbon (SOC mass on a fixed-depth (FD basis without considering changes in soil mass caused by changing bulk density (?b. This study evaluates the temporal changes in SOC caused by two factors: 1 changing SOC concentration; and 2 changing equivalent soil mass (ESM in comparison with FD. In addition, this study evaluates calculating changes in SOC stock over time using a minimum equivalent soil mass (ESMmin basis from a single sampling event compared with the FD scenario. A tillage [no-tillage (NT and chisel plow (CP]-crop rotation (multiple crop and continuous corn, and irrigation (full and delayed study was initiated in 2001 on Weld silt loam soil. After seven years, SOC concentration in the 0 - 30 cm depth was 19.7% greater in 2008 compared with 2001. Standardizing the soil mass of 2001 to the ESM of 2008 for each individual treatment showed an average gain in SOC of 5.8 Mg C·ha-1 in 2008 compared with 2001. However, the increase in SOC using ESM was twice the SOC gained with the FD calculation, where some treatments lost SOC after seven years of management. Estimating SOC levels using the ESMmin and, thereby, eliminating the confounding effect of soil ?b indicated that SOC stock was influenced by crop species and their interaction with irrigation, but not by tillage practices. Over all, the ESM calculation appears to be more effective in evaluating SOC stock than the FD calculation.

Maysoon M. Mikha

2013-05-01

330

Estimating root zone soil moisture from surface soil moisture data and soil-vegetation-atmosphere transfer modeling  

Science.gov (United States)

We studied the possibility of estimating root zone soil moisture through the combined use of a time series of observed surface soil moisture data and soil-vegetation-atmosphere transfer modeling. The analysis was based on the interactions between soil- biosphere-atmosphere surface scheme and two data sets obtained from soybean crops in 1989 and 1990. These data sets included detailed measurements of soil and vegetation characteristics and mass and energy transfer in the soil-plant-atmosphere system. The data measured during the 3-month experiment in 1989 are used to investigate the accuracy of soil reservoir retrievals, as a function of the time period and frequency of measurements of surface soil moisture involved in the retrieval process. This study contributes to better defining the requirements for the use of remotely sensed microwave measurements of surface soil moisture.

Wigneron, Jean-Pierre; Olioso, Albert; Calvet, Jean-Christophe; Bertuzzi, Patrick

1999-12-01

331

A soil mechanics approach to study soil compaction and traffic effect on the preconsolidation pressure of tropical soils  

International Nuclear Information System (INIS)

Several researchers have already demonstrated the causes and the effects of soil compaction. These studies showed that the soil compaction is a limiting factor in the agricultural production. The attributes of the soil conventionally monitored has not been capable to quantify the load support capacity of the soil, not allowing to foresee the levels of pressures that can be applied to the soils at different moisture conditions without additional soil compaction (structure degradation) happens. The researches done in the soil compressive behaviour of some tropical soils indicate that the pre-compression stress may be used as an alternative measure of the load support capacity and as a quantitative indicator of the structure sustainability of the tropical soils

2004-05-01

332

CATALYTIC POTENTIAL OF SOIL HYDROLASES IN NORTHEAST CHINA UNDER DIFFERENT SOIL MOISTURE CONDITIONS  

Directory of Open Access Journals (Sweden)

Full Text Available An incubation test with black soil (Phaeozem, Albic soil (Albic Luvisols, brown soil (Cambisols, and cinnamon soil (Chromic Luvisol from Northeast China was conducted under the conditions of 10%, 20% and30 % field capacity, and the kinetic parameters of soil urease, phosphatase, and arylsulphatase were determined, aimed to study the changes in the catalytic potential of these enzymes under different soil moisture conditions. All test enzymes exhibited typical Michaelis-Menten kinetic behaviors. The test enzymes exhibited the highest enzyme-substrate affinity (l/Km at 20% or 30% field capacity. With increasing soil moisture content, the Fmax of test soil urease decreased, while that of soil phosphatase and arylsulphatase increased, with the maximum Vmax/Km of urease at 20% field capacity and that of phosphatases and arylsulphatase at 30% field capacity. To control soil moisture condition could be a feasible way in regulating the biochemical transformation processes of soil nutrients catalyzed by soil hydrolases.

Y.L Zhang

2009-01-01

333

Evaluation of DSSAT soil-water balance module under cropped and bare soil conditions  

Directory of Open Access Journals (Sweden)

Full Text Available The performance of the soil water balance module (SWBM in the models of DSSAT v3.5 was evaluated against soil moisture data measured in bare soil and dry bean plots, in Paraná, southern Brazil. Under bare soil, the SWBM showed a low performance to simulate soil moisture profiles due to inadequacies of the method used to calculate unsaturated soil water flux. Improved estimates were achieved by modifying the SWBM with the use of Darcy's equation to simulate soil water flux as a function of soil water potential gradient between consecutive soil layers. When used to simulate water balance for the bean crop, the modified SWBM improved soil moisture estimation but underpredicted crop yield. Root water uptake data indicated that assumptions on the original method limited plant water extraction for the soil in the study area. This was corrected by replacing empirical coefficients with measured values of soil hydraulic conductivity at different depths.

Faria Rogério Teixeira de

2003-01-01

334

Efficiency comparison of conventional and digital soil mapping for updating soil maps  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This study compared the efficiency of geostatistical digital soil mapping (DSM) with conventional soil mapping (CSM) for updating soil class and property maps of a cultivated peatland in the Netherlands. For digital soil class mapping, the generalized linear geostatistical model was used. Digital mapping of the soil organic matter (SOM) content and peat thickness was done by universal kriging. The conventional soil class map was created by free survey, while the property maps were created wit...

Kempen, B.; Brus, D. J.; Stoorvogel, J. J.; Heuvelink, G. B. M.; Vries, F.

2012-01-01

335

Adsorption of methomyl by soils of southern Spain and soil components  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The adsorption of methomyl (S-methyl N-(methylcarbamoyloxy) thioacetimidate) by 14 soil samples of Southern Spain with different characteristics has been investigated studying the correlation between adsorption and soil properties and the effect of methomyl concentration and soil/solution ratio on adsorption of methomyl by soils. Adsorption has been expressed as the soil-water distribution coefficient Kd. Kd values slightly decreased when soil/solution ratio and methomyl concentration increas...

1993-01-01

336

Impact of Environmental Factors and Biological Soil Crust Types on Soil Respiration in a Desert Ecosystem  

Science.gov (United States)

The responses of soil respiration to environmental conditions have been studied extensively in various ecosystems. However, little is known about the impacts of temperature and moisture on soils respiration under biological soil crusts. In this study, CO2 efflux from biologically-crusted soils was measured continuously with an automated chamber system in Ningxia, northwest China, from June to October 2012. The highest soil respiration was observed in lichen-crusted soil (0.93±0.43 µmol m?2 s?1) and the lowest values in algae-crusted soil (0.73±0.31 µmol m?2 s?1). Over the diurnal scale, soil respiration was highest in the morning whereas soil temperature was highest in the midday, which resulted in diurnal hysteresis between the two variables. In addition, the lag time between soil respiration and soil temperature was negatively correlated with the soil volumetric water content and was reduced as soil water content increased. Over the seasonal scale, daily mean nighttime soil respiration was positively correlated with soil temperature when moisture exceeded 0.075 and 0.085 m3 m?3 in lichen- and moss-crusted soil, respectively. However, moisture did not affect on soil respiration in algae-crusted soil during the study period. Daily mean nighttime soil respiration normalized by soil temperature increased with water content in lichen- and moss-crusted soil. Our results indicated that different types of biological soil crusts could affect response of soil respiration to environmental factors. There is a need to consider the spatial distribution of different types of biological soil crusts and their relative contributions to the total C budgets at the ecosystem or landscape level.

Feng, Wei; Zhang, Yuqing; Jia, Xin; Wu, Bin; Zha, Tianshan; Qin, Shugao; Wang, Ben; Shao, Chenxi; Liu, Jiabin; Fa, Keyu

2014-01-01

337

Effects of Tillage Methods on Soil Fragmentation in Loamy-Clay Soils  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Problem statement: Soil fragmentation is a primary aim in tillage in order to create a favorable soil environment for crop growth. Soil fragmentation is defined as the process of breakdown and crumbling of soil aggregates. Currently, there is no published research data on optimum tillage operations for seedbed preparation in loamy-clay soils of western Caspian Sea region of Iran. Approach: Tests were conducted on a loamy-clay soil near the city of Ardabil, Iran, to investigate t...

Yousef Abbaspour-Gilandeh; Sharabiani, Vali R.; Ahmad Khalilian

2009-01-01

338

Assessment of Soil Intrinsic Properties Effects on Soil Structural Stability of Some Soils in Hamadan Province  

Directory of Open Access Journals (Sweden)

Full Text Available The effects of soil intrinsic properties on soil structural stability were evaluated. Soil samples (33 series with wide ranges of properties and structural stability were collected from Hamadan province. Two structural stability indices were used: mean weight diameter (MWD using Yoder method and De Leenheer-De Boodt index (DDI. Wetting pre-treatments (fast wetting to saturation and slow wetting to a matric suction of 30 kPa were applied before wetting. Linear and multiple regression relations of MWD and DDI with the soil intrinsic properties (organic matter, clay, fine clay, silt, sand, calcium carbonate, EC and pH were assessed. Results showed that organic matter had the highest impact on the two mentioned indices. Following organic matter, clay, fine clay and calcium carbonate were ranked respectively one after another. Fast wetting caused a higher aggregate break-down, due to its destructive energy, air entrapment, and non-uniform swelling of the soil whereas slow wetting exhibited better differentiation of soils with low structural stability. The findings of this research demonstrated high agreement (R2>75% between the MWD and DDI, recommended both to be used for evaluating of the aggregate stability in Hamedan province

M. Nikpur

2012-03-01

339

Behavior of unsaturated soil and its influence on soil - soil interaction at an interface  

International Nuclear Information System (INIS)

The interface failure between caps and natural soil in trenches containing buried low-level nuclear-waste material was investigated in this study. The Casa Grande Highway Farm (CGHF) soil was used for the entire investigation. This soil is described as being a silty sand with approximately 23% by weight passing sieve No. 200. Other preliminary testing was performed on the same soil. Isotropically consolidated drained (CID) tests were performed on the laboratory compacted samples at different degree of saturation including fully saturated specimens. Suction pressure was measured in the laboratory by adopting pressure-plate extractor and compared with determine effective suction in triaxial testing. A generalized failure equation, in terms of strength parameters and suction pressure, was defined for all degrees of saturation. Extensive interface tests were performed in the conventional direct shear machine with some modification. Similar to trench cap soil and natural soil in the field, the test specimens were prepared at different degrees of saturation and density (compaction effort). An interface element and the modified bounding surface model and elasticity model was used in a finite-element program to predict the interface response for the laboratory results and actual field problems

1987-01-01

340

Soil amendment: a technique for soil remediation of lactofen.  

Science.gov (United States)

Lactofen, a member of the diphenyl ether chemical family, shows great potential for the control of broadleaf weeds associated with leguminous crops. It presents a high degree of selectivity when applied post-emergence to soybean and peanut crops. This paper presents the persistence of lactofen under a soybean crop under various conditions, including without remediation techniques, under soil solarization with polyethene sheets, and soil solarization followed by straw amendment. The results indicate that dissipation is faster when using the soil solarization technique (set II) compared to no treatment (set I) and is further enhanced by tstraw amendment, where almost 90% dissipation was recorded (set III). The dissipation followed first-order kinetics with a half-life that varied from 30 to 10 days. The half-life of lactofen was 15 days in treatments of soil solarization and straw amendments alone, indicating that both techniques have to be used in combination to achieve successful remediation of soil. Use of biodegradable polythene/substitute material will make this process a popular technique and may also improve its commercial viability. PMID:17599224

Mukherjee, Irani; Gopal, Madhuban; Das, T K

2007-07-01

 
 
 
 
341

210Pb in Estonian Soil  

International Nuclear Information System (INIS)

Full text: Activity concentrations of 210Pb as a function of depth have been studied in natural soil profiles in Estonia. Most of the samples were collected from northeastern part of Estonia, characterised by elevated activity concentrations of U/Ra in soil (up to 320 Bq/kg), by enhanced technogenic fly-ash radionuclide deposition and by radon exhalation. Collected soil samples were analysed for 210Pb by using low-background gamma spectrometer with a HPGe planar detector. For each sample in a sealed container, a self-attenuation correction basing on the direct 45 keV gamma-ray transmission measurements and the actual measurement geometry model was applied in the spectrum analysis. For a comparison, in the same samples both activity concentrations of 226Ra and radon emanation coefficients were measured by using coaxial HPGe gamma spectrometry. In all studied soil profiles maximum activity concentrations of 210Pb were found in the top surface layer. The surface maximum was followed by a considerable decrease in activity concentration with increasing depth. In surface soil the activity concentration ratio of 210Pb to 226Ra demonstrated a significant site-specific variation with values up to 5 or 6, while it was approximately equal to 1 in deep soil layers. Radon emanation coefficients in the range of 20-30% were determined for dry soil. A simple one-dimensional model describing depth distributions of the 210Pb activity was applied to derive the 210Pb deposition rates and migration parameters characteristic to the sampling sites. (author)

2001-05-20

342

Uranium speciation in Fernald soils  

International Nuclear Information System (INIS)

This interim progress report describes new experimental data collected from October 1, 1992 through May 31, 1993 as part of the Characterization Task of the Uranium in Soils Integrated Demonstration of the Office of Technology Development, Office of Environmental Restoration and Waste Management of the United States Department of Energy. X-ray absorption and optical luminescence spectroscopies have been used to analyze the uranium remaining in contaminated soils from the Fernald site after these samples were treated by various decontamination technologies under development within this Integrated Demonstration. The treatment technologies included soil washes with carbonate, citrate, Tiron, and Tiron/dithionite mixtures. The effectiveness of these procedures is discussed in a separate report from the Decontamination Task group. The characterization results indicate that following the application of all of these treatment strategies the uranium remaining in the soil is still best characterized as being primarily in the hexavalent oxidation state. However, for the A-series soils from the Incinerator Area, the speciation of this remaining uranium is different than seen previously based on the x-ray absorption data. The luminescence data for these treated soils also demonstrate that there is a decrease in size and quantity of the particulate hexavalent uranium that gives rise to the structured green emission. Thus, all treatment technologies do seem to generate a more dispersed, finer-grained form of uranium. For several treated samples a characteristic luminescence signal was found indicative of a schoepite phase of uranium. New results are also reported for untreated Fernald soil samples and reference uranium mineral phases

1993-01-01

343

Soil Water and Temperature System (SWATS) Handbook  

Energy Technology Data Exchange (ETDEWEB)

The soil water and temperature system (SWATS) provides vertical profiles of soil temperature, soil-water potential, and soil moisture as a function of depth below the ground surface at hourly intervals. The temperature profiles are measured directly by in situ sensors at the Central Facility and many of the extended facilities of the SGP climate research site. The soil-water potential and soil moisture profiles are derived from measurements of soil temperature rise in response to small inputs of heat. Atmospheric scientists use the data in climate models to determine boundary conditions and to estimate the surface energy flux. The data are also useful to hydrologists, soil scientists, and agricultural scientists for determining the state of the soil.

Bond, D

2005-01-01

344

4.3 Environmental media: soil  

International Nuclear Information System (INIS)

An overview about the Austrian soil condition covering the period 2001-2003 is presented. It provides information on selected inorganic pollutants like copper, chromium, cadmium, cesium, lead, nickel, zinc and mercury as well as organic pollutants (polycyclic aromatic hydrocarbons, organic halogen compounds (pentachlorophenol, PCB) etc.). First Austria-wide evaluations were derived from the soil information system BORIS, which provides a survey of selected pollutant concentrations in Austrian top soils. This comprehensive data collection includes major soil surveys, such as the data from soil inventories of the Federal Provinces, the Austrian forest soil inventory, the Austria-wide radio-cesium survey, as well as data from more than 30 other local surveys regarding special soil issues and problems (conurbation, industrial sites, etc.). In general the condition of Austrian soils may be considered good, however still, there are some regions with polluted soils, particularly in the Austrian Alps. (nevyjel)

2004-01-01

345

Soil compaction and growth of woody plants  

International Nuclear Information System (INIS)

Although soil compaction in the field may benefit or inhibit the growth of plants, the harmful effects are much more common. This paper emphasizes the deleterious effects of predominantly high levels of soil compaction on plant growth and yield. High levels of soil compaction are common in heavily used recreation areas, construction sites, urban areas, timber harvesting sites, fruit orchards, agroforestry systems and tree nurseries. Compaction can occur naturally by settling or slumping of soil or may be induced by tillage tools, heavy machinery, pedestrian traffic, trampling by animals and fire. Compaction typically alters soil structure and hydrology by increasing soil bulk density; breaking down soil aggregates; decreasing soil porosity, aeration and infiltration capacity; and by increasing soil strength, water runoff and soil erosion. Appreciable compaction of soil leads to physiological dysfunctions in plants. Often, but not always, reduced water absorption and leaf water deficits develop. Soil compaction also induces changes in the amounts and balances of growth hormones in plants, especially increases in abscisic acid and ethylene. Absorption of the major mineral nutrients is reduced by compaction of both surface soils and subsoils. The rate of photosynthesis of plants growing in very compacted soil is decreased by both stomatal and non-stomatal inhibition. Total photosynthesis is reduced as a result of smaller leaf areas. As soils become increasingly compacted respiration of roots shifts toward an anaerobic state. Severe soil compaction adversely influences regeneration of forest stands by inhibiting seed germination and growth of seedlings, and by inducing seedling mortality. Growth of woody plants beyond the seedling stage and yields of harvestable plant products also are greatly decreased by soil compaction because of the combined effects of high soil strength, decreased infiltration of water and poor soil aeration, all of which lead to a decreased supply of physiological growth requirements at meristematic sites. Many protocols have been developed, with variable success, to alleviate the adverse effects of soil compaction on the growth and development of woody plants. These include planting of compaction-tolerant species, controlling vehicular and animal traffic, amending soils by adding coarse materials and,or organic matter, replacing compacted soils with uncompacted soils, loosening soils with aerating equipment, installing drainage systems and judiciously applying fertilizers. Prevention of soil compaction before planting is usually much preferred over post-planting treatments because the latter are expensive and difficult to apply, may not be adequately effective and may injure plant roots

1999-01-01

346

Soil gas radon concentrations measurements in terms of great soil groups  

International Nuclear Information System (INIS)

In this study, soil gas radon concentrations were investigated according to locations, horizontal soil layers and great soil groups around Tuzla Fault, Seferihisar-?zmir. Great soil groups are a category that described the horizontal soil layers under soil classification system and distributions of radon concentration in the great soil groups are firstly determined by the present study. According to the obtained results, it has been showed that the radon concentrations in the Koluvial soil group are higher than the other soil groups in the region. Also significant differences on location in same great soil group were determined. The radon concentrations in the Koluvial soil groups were measured with respect to soil layers structures (A, B, C1, and C2). It has been observed that the values increase with depth of soil (C2>C1>B>A). The main reason may be due to the meteorological factors that have limited effect on radon escape from deep layers. Although fault lines pass thought the study area radon concentrations were varied location to location, layer to layer and great group to great group. The study shows that a detailed location description should be performed before soil radon measurements for earthquake predictions. -- Highlights: • Soil gas radon measurements on different great soil groups using LR 115 Type 2 solid state nuclear detectors. • An evaluation of radon level in terms of great soil groups, measurement location and soil horizons. • Modified track counting on LR 115 detectors

2013-12-01

347

Soil Degradation and Soil Value in Slovakia – Two Problems with Common Denominator  

Directory of Open Access Journals (Sweden)

Full Text Available Soil use is oft en accompanied by its degradation. Immediate reason of soil degradation in agriculture is the non-respecting the principles of good agricultural practice. Giving long-term precedence to production function over remaining ecological ones as well as supporting the land consumption for economy development by governmental bodies are next reasons of soil degradation and mirror the societal values and priorities.Soil provides many services that in soil science are defined as soil functions. Besides biomass production the soil provides ecological and socio-economic functions. Use of soil and its functions is closely linked to soil ecological, societal and economic values. Preference to economic interests together with reluctance to search compromise solutions is oft en manifesting in soil degradation. Economic valuation of soil and its ecological functions is considered a possible way for improvement of soil protection especially in modification of soil price at its permanent consumption. In spite of that financial values can not be used as a base for forming of ethical values, which are imminently connected with human approach towards soil and its degradation, and which are essentially needed by global society. Ethical human values, based on basic beliefs and convictions, influence of human attitude to the soil, and they influence on soil use can be considered as common denominator of soil degradation and soil value, respectively.

Radoslav Bujnovský

2011-03-01

348

Spatial and temporal variability of soil electrical conductivity related to soil moisture  

Directory of Open Access Journals (Sweden)

Full Text Available Soil electrical conductivity (ECa is a soil quality indicator associated to attributes interesting to site-specific soil management such as soil moisture and texture. Soil ECa provides information that helps guide soil management decisions, so we performed spatial evaluation of soil moisture in two experimental fields in two consecutive years and modeled its influence on soil ECa. Soil ECa, moisture and clay content were evaluated by statistical, geostatistical and regression analyses. Semivariogram models, adjusted for soil moisture, had strong spatial dependence, but the relationship between soil moisture and soil ECa was obtained only in one of the experimental fields, where soil moisture and clay content range was higher. In this same field, coefficients of determinations between soil moisture and clay content were above 0.70. In the second field, the low soil moisture and clay content range explain the absence of a relationship between soil ECa and soil moisture. Data repetition over the years, suggested that ECa is a qualitative indicator in areas with high spatial variability in soil texture.

José Paulo Molin

2013-02-01

349

Spatial and temporal variability of soil electrical conductivity related to soil moisture  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Soil electrical conductivity (ECa) is a soil quality indicator associated to attributes interesting to site-specific soil management such as soil moisture and texture. Soil ECa provides information that helps guide soil management decisions, so we performed spatial evaluation of soil moisture in two [...] experimental fields in two consecutive years and modeled its influence on soil ECa. Soil ECa, moisture and clay content were evaluated by statistical, geostatistical and regression analyses. Semivariogram models, adjusted for soil moisture, had strong spatial dependence, but the relationship between soil moisture and soil ECa was obtained only in one of the experimental fields, where soil moisture and clay content range was higher. In this same field, coefficients of determinations between soil moisture and clay content were above 0.70. In the second field, the low soil moisture and clay content range explain the absence of a relationship between soil ECa and soil moisture. Data repetition over the years, suggested that ECa is a qualitative indicator in areas with high spatial variability in soil texture.

Molin, José Paulo; Faulin, Gustavo Di Chiacchio.

350

Inverse Method for Estimating the Spatial Variability of Soil Particle Size Distribution from Observed Soil Moisture  

Energy Technology Data Exchange (ETDEWEB)

Soil particle size distribution (PSD) (i.e., clay, silt, sand, and rock contents) information is one of critical factors for understanding water cycle since it affects almost all of water cycle processes, e.g., drainage, runoff, soil moisture, evaporation, and evapotranspiration. With information about soil PSD, we can estimate almost all soil hydraulic properties (e.g., saturated soil moisture, field capacity, wilting point, residual soil moisture, saturated hydraulic conductivity, pore-size distribution index, and bubbling capillary pressure) based on published empirical relationships. Therefore, a regional or global soil PSD database is essential for studying water cycle regionally or globally. At the present stage, three soil geographic databases are commonly used, i.e., the Soil Survey Geographic database, the State Soil Geographic database, and the National Soil Geographic database. Those soil data are map unit based and associated with great uncertainty. Ground soil surveys are a way to reduce this uncertainty. However, ground surveys are time consuming and labor intensive. In this study, an inverse method for estimating mean and standard deviation of soil PSD from observed soil moisture is proposed and applied to Throughfall Displacement Experiment sites in Walker Branch Watershed in eastern Tennessee. This method is based on the relationship between spatial mean and standard deviation of soil moisture. The results indicate that the suggested method is feasible and has potential for retrieving soil PSD information globally from remotely sensed soil moisture data.

Pan, Feifei [University of Texas; Peters-lidard, Christa D. [NASA Goddard Space Flight Center; King, Anthony Wayne [ORNL

2010-11-01

351

DEVELOPING ECOLOGICAL SOIL SCREENING LEVELS: BENCHMARK VALUES FOR SOIL INVERTEBRATES, PLANTS, AND MICROBIAL FUNCTIONS  

Science.gov (United States)

Soils are repositories for environmental contaminants (COCs) in terrestrial ecosystems. Time, effort, and money repeatedly are invested in literature-based evaluations of potential soil-ecotoxicity......

352

Optimization of nitrogen for soil bioventing of gasoline contaminated soil  

Energy Technology Data Exchange (ETDEWEB)

Bioventing, a promising in situ technology that uses low or intermittent airflow rates to produce oxygen-rich conditions in the aerated zone of the soil, promotes the growth of indigenous microorganisms, which degrade hydrocarbon contaminants that are frequently found around underground storage tanks. This study was undertaken to determine the optimum form and concentration of nitrogen that will effectively stimulate naturally occurring bacteria and fungi to obtain the highest degradation possible in a soil system using bioventing to treat gasoline-contaminated soil. Results showed that biodegradation was limited at high C:N ratios by the availability of nitrogen and at low C:N ratios by acidification. Aerobic bacteria were responsible for most of the biodegradation that occurred. Indigenous fungi had no significant effect on the rate of biodegradation. 47 refs., 7 tabs., 1 fig.

Shewfelt, K.; Zytner, R. G. [University of Guelph, School of Engineering, Guelph, ON (Canada); Lee, H. [University of Guelph, Dept. of Environmental Biology, Guelph, ON (Canada)

2005-01-01

353

A geotechnical characterization of lunar soils and lunar soil simulants  

Science.gov (United States)

Many of the essential materials needed for the construction of a lunar base can be produced from the resources found on the lunar surface. Processing natural resources on the moon into useful products will reduce the need, and the cost, to bring everything from earth. The lunar regolith has been intensely studied with respect to understanding the formation of the moon and the earth, but as a construction material, the regolith is poorly characterized and poorly understood. To better understand how to 'work' with the lunar regolith, four loosely related research projects were conducted. Two projects relate to characterizing and understanding the geotechnical properties of regolith, two projects relate to manipulating and processing granular materials in the lunar environment. The shapes of lunar soil grains are characterized using fractals - results directly and quantitatively describe the rugged reentrant nature of the large scale structure and the relatively smooth surface texture of lunar soil grains. The nature of lunar soil cohesion is considered using tensile strength measurements of lunar soil simulant. It is likely that mechanical interlocking of irregular grains is the primary cause of lunar soil cohesion. This mechanism is highly sensitive to grain shape, but relatively insensitive to particle packing density. A series of experiments are conducted to try to understand how granular particles might sort by size in a vacuum. Even in a vacuum, fine particle subjected to shear strain segregate by a mechanism called the random fluctuating sieve The random fluctuating sieve also controls particle motion that determines the structure of wind-blown sand ripples. Hybrid microwave heating was used to sinter large structural bricks from lunar soil stimulant. While heating was prone to thermal runaway, microwave heating holds great promise as a simple, direct method of making sintered structural bricks.

Graf, John Carl

354

Soil selenium: Laboratory comparisons and soil/backfill variability  

Energy Technology Data Exchange (ETDEWEB)

Various analytical methods have been used to determine selenium (Se) in soils, overburden, and plants. Inter-Mountain Laboratories and the Soil and Environmental Chemistry Laboratory at the University of Wyoming conducted a study to determine the variability of soil Se by independently analyzing 20% of the soil/backfill samples from an Abandoned Coal Mine Land research project {open_quotes}Relationship Between Soil Selenium Concentrations and Selenium Uptake by Vegetation on Surface Coal Mine Lands in Wyoming{close_quotes}. The quality control/quality assurance program for this project revealed excellent agreement between the two laboratories. For example, hot water, AB-DTPA, and phosphate extractable Se results from the two laboratories were found to be highly correlated (R{sup 2} {ge} 0.95) by linear regression analyses. Both laboratories followed {open_quotes}Standard Operating Procedures{close_quotes} which included determination of Se by atomic adsorption spectroscopy with hydride generation (Varian HGA-76). Five methods used to determine soil Se (i.e., total Se and four methods of extractable Se - hot water, AB-DTPA, phosphate, and saturated paste) were compared among three cores sampled within a one meter triangle at different sites (native and reclaimed locations) and depths (5 at native and 3 at unclaimed sites). A wide range in the coefficient of variation (CV) was noted (0 to 118%); however, the larger CV`s tended to be grouped at specific sites and depths, and with certain extractants. Of 831 CV`s calculated, only 10 (or 1.2%) were greater than 100%. Average CV`s for mine type and ecological system (i.e., native versus reclaimed) were approximately 25%. Overall, total Se varied the least among the five Se variables followed by phosphate < AB-DTPA < hot water < saturated paste extractable Se.

Pasch, R.N. [Inter-Mountain Laboratories, Inc., Sheridan, WY (United States); Vance, G.F. [Univ. of Wyoming, Laramie, WY (United States)

1995-09-01

355

Innovative technologies for soil cleanup  

International Nuclear Information System (INIS)

These notes provide a broad overview of current developments in innovative technologies for soil cleanup. In this context, soil cleanup technologies include site remediation methods that deal primarily with the vadose zone and with relatively shallow, near-surface contamination of soil or rock materials. This discussion attempts to emphasize approaches that may be able to achieve significant improvements in soil cleanup cost or effectiveness. However, since data for quantitative performance and cost comparisons of new cleanup methods are scarce, preliminary comparisons must be based on the scientific approach used by each method and on the sits-specific technical challenges presented by each sold contamination situation. A large number of technical alternatives that are now in research, development, and testing can be categorized by the scientific phenomena that they employ and by the site contamination situations that they treat. After cataloging a representative selection of these technologies, one of the new technologies, Dynamic Underground Stripping, is discussed in more detail to highlight a promising soil cleanup technology that is now being field tested

1992-09-21

356

Precipitation of radiostrontium in soil  

International Nuclear Information System (INIS)

The purpose of this study was to learn whether precipitated Ca-Sr phases can be formed in soil when the adsorptive characteristics of soil was amended with the additions of sodium solutions of hydroxide, fluoride, carbonate, oxalate, phosphate, aluminate and silicate. Candidate insoluble Ca-Sr phases include the carbonate, oxalate, fluoride, phosphate, aluminate, and silicate. More important than the formation of these phases in soil is the knowledge of how isotopically/isomorphically exchangeable any precipitated activity would be with dissolved Ca in a leaching groundwater. These questions were addressed experimentally by treating soils with a fixed quantity of the particular precipitating anion solution and, subsequently, spiking this mixture with an increment of CaCl2 containing either 45Ca, 85Sr, or 22Na and observing the radioisotopic distribution. Two additional increments of CaCl2 were sequentially added and the redistributions of radioisotopes observed. Such a batch equilibrium method was designed to simulate a chemically-modifed soil coming into contact with a radiostrontium contaminated groundwater and the subsequent leaching of any nascent precipitated phase by additional groundwater. The choice of precipitating anions were found to carbonate and phosphate. Although preliminary column leaching experiments indicated that carbonate is slightly more effective than phosphate in immobilizing radiostrontium, both chemicals have potential

1980-11-20

357

An Alaska Soil Carbon Database  

Science.gov (United States)

Database Collaborator's Meeting; Fairbanks, Alaska, 4 March 2009; Soil carbon pools in northern high-latitude regions and their response to climate changes are highly uncertain, and collaboration is required from field scientists and modelers to establish baseline data for carbon cycle studies. The Global Change Program at the U.S. Geological Survey has funded a 2-year effort to establish a soil carbon network and database for Alaska based on collaborations from numerous institutions. To initiate a community effort, a workshop for the development of an Alaska soil carbon database was held at the University of Alaska Fairbanks. The database will be a resource for spatial and biogeochemical models of Alaska ecosystems and will serve as a prototype for a nationwide community project: the National Soil Carbon Network (http://www.soilcarb.net). Studies will benefit from the combination of multiple academic and government data sets. This collaborative effort is expected to identify data gaps and uncertainties more comprehensively. Future applications of information contained in the database will identify specific vulnerabilities of soil carbon in Alaska to climate change, disturbance, and vegetation change.

Johnson, Kristofer; Harden, Jennifer

2009-05-01

358

SSSA: Soil Science Society of America  

Science.gov (United States)

The Soil Science Society of America (SSSA) is the professional organization dedicated to the advancement of "the discipline and practice of soil science by acquiring and disseminating information about soils in relation to crop production, environmental quality, ecosystem sustainability, bioremediation, waste management and recycling, and wise land use." After viewing SSSA's bylaws, researchers can learn about the annual international meeting held in Seattle from October 31st through November 4th, 2004. Students can find out about scholarships, awards, fellowships, and career opportunities. Soil scientists can obtain information on the fundamental soil science exam and the performance objectives. The website also provides summaries of recent findings published in soil science journals.

359

Measuring soil strains using fiber optic sensors  

Science.gov (United States)

The measurement of strain within a compacted soil mass using optical fibers was demonstrated. The sensitivity of the fiber optic sensor was shown to match that of an existing soil strain sensor. Experimental data were gathered by dynamically loading the soil. Data from the optical fibers was processed by a Fabry-Perot interferometer into a localized strain. The data was verified by comparing with data obtained from a LVDT and a commercial soil strain sensor as well as theoretical data obtained from a finite element analysis. The data indicate that fiber optic sensors have the ability to detect viscoelastic soil strains and may be used to measure the permanent deformation of soil.

Miller, Craig E.; Sharma, M. G.; Sherwood, James A.

1996-04-01

360

World Reference Base for Soil Resources  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In 1998, the International Union of Soil Sciences (IUSS) officially adopted the world reference base for soil resources (WRB) as the Union's system for soil correlation. The structure, concepts, and definitions of the WRB are strongly influenced by the FAO-UNESCO legend of the soil map of the world (1-2). At the time of itsinception, the WRB proposed 30 "Soil Reference Groups" accommodating more than 200 ("second level") soil units. WRB (3-5) was endorsed by the IUSS in 1998 and provides an o...

Deckers, J. A.; Driessen, P. M.; Nachtergaele, F. O.; Spaargaren, O. C.

2002-01-01

 
 
 
 
361

Absorption of gamma radiation in soil  

International Nuclear Information System (INIS)

Most important properties of soil as a shielding material were analysed. Gamma radiation absorption coefficient for soil was measured under laboratory conditions. Shielding potential of soil was measured under natural conditions as well. Comparison of shielding potentials of soil and ordinary concrete (density = 2.35 g/cm3), showed that 1 m thick layer of soil is equivalent to 70 cm thick layer of concrete for absorption of gamma radiation from Co-60 (mean energy = 1.25 MeV). The obtained results are needed for estimation of shielding potential of soil layers

1967-01-01

362

Deformation Parameters of Macrofragment Soils in Soil Dams  

Directory of Open Access Journals (Sweden)

Full Text Available The author tries to generalize the results of testing of macrofragment soils, made by other authors and to give recommendations on defining nonlinear model soils parameters. The article gives definitions of volume weight of gravel and pebble ground and mined rock. It’s shown that starting shift modules depending on stress due to prestress can be described in power formula. The author confirms Professor L.N. Rasskazov’s idea about the possibility of describing volume deformation in contraction through intensity of tangent deformation.

Sainov Mikhail Petrovich

2014-06-01

363

The soil fungi communities of peat soils in the Narew National Park  

Directory of Open Access Journals (Sweden)

Full Text Available The study was conducted in the years 2003-2004 on four low peatland peat soil profiles located in the Narew National Park. All studied soils were sedge peat soils sampled from various habitats. The recognition of the soil fungi communities and their stratification in the studied profiles were the aim of the study. The 214 isolates were made, which were represented by 45 species. The reason for little differentiation of quantitative-qualitative structures of soil fungi communities in peat soils is their high moisture. The distinct differentiation among the soil fungi communities was observed. These results suggest that not only the soil-forming process affects the soil fungi communities development but also the soil properties, which were under influence in the past and have been still affected by the habitat conditions, are very important to the development process of soil fungi communities.

Zofia Tyszkiewicz

2005-12-01

364

The use of some soil aggregate indices to assess potential soil loss in soils of south-eastern nigeria  

Directory of Open Access Journals (Sweden)

Full Text Available Six aggregate indices and some soil properties were evaluated to predict potential soil loss in soils of Southeastern Nigeria. Of the aggregate indices tested, dispersion ratio (DR, Wischmeier's erodibility index (K, clay dispersion index (CDI and clay floccula-tion index (CFI ranked higher than geometric mean diameter (GMD and mean-weight diameter (MWD in predicting potential soil loss. Some aggregate indices found to correlate well with soil loss are in order of decreasing predictability CFI>CDI>DR>GMDŁMWD while organic carbon, % clay content and Fe.O. are some soil characteristics that predict the potential of these soils to erode fairly accurately. Dispersion and flocculation are shown to be influenced by metal-organic complexes which often leads to increased potential soil loss.

J.S.C. Mbagwu

1995-06-01

365

Soil moisture distribution over time in a clay loam soil in Kosovo  

Directory of Open Access Journals (Sweden)

Full Text Available Studying the soil moisture distribution over time in a given soil profile is the object of the present study. The way the soil moisture gets distributed over soil profile depends particularly on the soil texture and on the soil suction gradients developed. However, it changes continuously over time for a given soil depth. The method of determining the soil moisture distribution over time is based on the measuring of soil moisture suctions developed and the soil moisture contents in various times, but in a given soil depth (internal drainage method [7]. The soil depths under investigation are four, starting from 0cm to 60cm, which means that the most important depth of soil profile is considered. Such measurements are supposed to be done over soil profile when the soil water flow is already ceased, in the conditions of preventing the evaporation [1, 7, and 9]. Therefore, to determine the soil moisture distribution over time, a plot of 8m x 6m or 48 m2 with no plants was set. The tensiometers and the electronic devices for soil moisture content measurements were installed in four soil depths. The plot was previously wetted and covered by a plastic to prevent the evaporation. In this way, it was made sure that the only possibility for water is to move internally, which gave us the opportunity to measure the changes in soil water content and in soil water suction over time. The final result showed that the dependency of soil water suction and soil moisture content over time is a power function (expressed as a semi logarithmic function, basically.

Abdullah Nishori

2013-02-01

366

Plant biodiversity impacts on soil stability  

Science.gov (United States)

In recent times, growing threats to global biodiversity have raised awareness from the scientific community, with particular interest on how plant diversity impacts on ecosystem functioning. In the field of plant-soil interactions, much work has been done to research the implications of species loss, primarily focussing on biological processes such as plant productivity, microbial activity and carbon cycling. Consequently, virtually nothing is known about how plant diversity might impact on soil physical properties, and what mechanisms might be involved. This represents a serious gap in knowledge, given that maintaining soils with good structural integrity can reduce soil erosion and water pollution, and can lead to improved plant yield. Therefore, there is a need for a greater understanding of how plant communities and ecological interactions between plant roots and soils can play a role in regulating soil physical structure. Soil aggregation is an important process in determining soil stability by regulating soil water infiltration and having consequences for erodibility. This is influenced by both soil physical constituents and biological activity; including soil organic carbon content, microbial growth, and increased plant rooting. As previously mentioned, plant diversity influences carbon dynamics, microbial activity and plant growth, therefore could have substantial consequences for soil aggregate stability. Here, we present results from a series of plant manipulation experiments, on a range of scales, to understand more about how plant diversity could impact on soil aggregate stability. Soils from both a plant manipulation mesocosm experiment, and a long term biodiversity field study, were analysed using the Le Bissonnais method of aggregate stability breakdown. Increasing plant species richness was found to have a significant positive impact on soil aggregate stability at both scales. In addition to this, the influence of species identity, functional group identity, and root traits were also investigated. Studying at the interface of ecology and soil physics, this work aims to provide scope for a new direction in soil biodiversity studies.

Gould, Iain; Quinton, John; Bardgett, Richard

2014-05-01

367

Soil Enzymes Research: A Review  

Directory of Open Access Journals (Sweden)

Full Text Available Enzymes are biologically produced proteinic substances having specific activation in which they combine with their substrates in such a stereoscopic position that they cause changes in the electronic configuration around certain susceptible bonds. Their significance in all spheres including soil, is worth tested and reported. In plant nutrition their role cannot be substituted by any other substance and its function is quite pragmatic in solubilizing and dissolving the much needed food in ionic forms for the very survival of animal and plant kingdom. World over, innumerable researchers have contributed their efforts in exploring enzymes. This paper reviews some of the important factors affecting its behaviour, reactions in soil environment, correlation with other enzymes and soil properties, preceded by its historical perspective and sources of production.

Zahir Ahmad Zahir

2001-01-01

368

Biosurfactant-enhanced soil bioremediation  

Energy Technology Data Exchange (ETDEWEB)

Bioremediation of soil contaminated with organic chemicals is a viable alternative method for clean-up and remedy of hazardous waste sites. The final objective in this approach is to convert the parent toxicant into a readily biodegradable product which is harmless to human health and/or the environment. Biodegradation of hydrocarbons in soil can also efficiently be enhanced by addition or in-situ production of biosufactants. It was generally observed that the degradation time was shortened and particularly the adaptation time for the microbes. More data from our laboratories showed that chlorinated aromatic compounds, such as 2,4-dichlorophenol, a herbicide Metolachlor, as well as naphthalene are degraded faster and more completely when selected biosurfactants are added to the soil. More recent data demonstrated an enhanced biodegradation of heavy hydrocarbons in petrochemical sludges, and in contaminated oil when biosurfactants were present or were added prior to the biodegradation process.

Kosaric, N.; Lu, G.; Velikonja, J. [Univ. of Western Ontario, London, Ontario (Canada)

1995-12-01

369

Diffusion of cations in soils  

International Nuclear Information System (INIS)

The rate at which nutrients move through soil can possibly limit their availability to plants; in some cases this movement is mainly by diffusion. Several studies of cation diffusion in soils have been reported. For soils or similar materials, the most easily interpreted diffusion measurements relate to self-diffusion which can be studied when a concentration gradient of radiotracers is set up in a system where the non-radioactive ions are uniformly distributed. In this paper a method of determining self-diffusion coefficients for cations is described and previously published results obtained by this method are reconsidered together with some unpublished data. The role of cation diffusion in plant nutrient supply is discussed in the light of these results

1965-11-01

370

Global Soil Moisture Data Bank  

Science.gov (United States)

From the Department of Environmental Sciences at Rutgers, The State University of New Jersey, highlights of this site include data sets from soil moisture observation stations in Eurasia (including China, India, Mongolia, and the former Soviet Union) as well as the slightly less exotic locales of Iowa and Illinois. These data sets are available by clicking on a map of Eurasia and the two US states. Links to other data sets include those for Australia, Brazil, Europe, Russia and Ukraine, and the US. The site also offers abstracts and full-text papers on soil moisture research. Finally, additional sections lead to carefully selected links for model calculations, related projects, and soil moisture measurements.

371

Impacts of soil structure on crop growth  

Directory of Open Access Journals (Sweden)

Full Text Available Intensive agricultural utilisation of soils may change the structural status and through it the credibility and fertility of soils. Since soil structure has not been quantified explicitly, studying structure-related soil phenomena is still actual. The goal of the present study was to apply field measurements on structure related soil hydrophysical properties and to study their mutual effect on crop growth. Near hydraulic water conductivity, bulk density, water retention characteristics of soils were measured in a wheat and a maize field as well as the soil water content dynamics during the vegetation period. Simulation models (SOIL and SOILN were applied for studying different effects of soil structural status on winter wheat and maize crop's developments and on yields. Simulation results showed that water limitation in fields having normal and high bulk density topsoil developed gradually. In the low bulk density field case, water limitation on crop growth is noticeable almost from the beginning of crop growth. Though the combined effects of soil water stress and rooting due to soil structure resulted in marked differences in simulated yields, the effect of the saturated water conductivity and bulk density on the crop yield alone proved to be non significant. However, when a consequence was introduced regarding the plant root distribution, which differs in different soil physical conditions, a strong effect on the crop's growth was detected. This finding demonstrates the complex nature of the phenomenon called structural status of soil, and it definitely requires further research.

Farkas C.S.

1997-06-01

372

Evaluation of Desertification Intensity Using Soil Indices  

Directory of Open Access Journals (Sweden)

Full Text Available Soil characteristics are the most powerful factors in desertification phenomenon. The purpose of this study was investigating soil characteristics as indices for evaluating desertification intensity. The most important indicators of the soil that affect desertification were selected in the present study. Soil samples were taken from Segzi desert vicinity located in the east of Isfahan city with surface area of 112,167 ha. Soil indices such as Soil texture, soil gypsum percentage, the content of HCO3-1, electrical conductivity (EC, pH, the percentage of the organic matter, the content of the soil sodium, chloral and sodium absorption ratio (SAR were selected. All of these indices were calculated on the thirty four soil samples. After ensuring of the normality of the samples by Klomogrov-Smirnov test, the mentioned indices were imported into GIS for delineating soil characteristics maps. To delineate distribution maps of each soil indice, inverse distance weighting and ordinary and discrete Kriging methods were applied, and appropriate method was selected. Each layer was scored based on MEDALUS model, and the final characteristic maps were then generated using soil geometric mean indices. Results showed that the affected areas of the average, severe and very severe classes of desertification were calculated about 66000, 45650 and 517 ha, respectively. The results also revealed that the indices of the organic matter, soil gypsum percentage, electrical conductivity and SAR were the most influential indicators, which affected desertification in the study area.

A. Khanamani

2013-06-01

373

Sorption of radionuclides in soil complex  

International Nuclear Information System (INIS)

Soil is an important medium in which the transport of radionuclides and of other contaminants into the environment is realised, where it reaches the food chain by root plant system. The typical soils of the Slovak Republic are brown soils and brown forest soils. The important characteristic of soils from the point of view of contamination is their texture; because the particles with different size are obviously differentiated not only by their specific surface but also by their mineralogical and chemical composition. In natural conditions the radionuclides, which transverses into solution, can migrate in the profile of soil in the form of finely depressive and colloid particles, as well as instant complex forms and they can be connected with mineral and organic component of soils. The effective movement of radionuclides in soil matrix is determined by flux ground water and by sorption of a radionuclide on individual components of soil. The humic components of soil have strong influence. Concentration of radionuclides trapped on the surface of soil decreases with the time, by transfer into plants, by migration into deeper layers of soil, by windily erosion, by co-elution with water. Notably the loamy components in soils have high ion-exchange capacity. The sorbed radionuclides on the exchange surfaces are accessible for root system of plants. Determination of the components, on which the radionuclide is fixed, is carried out by speciation of the radionuclide in the solid phase, the most frequently by sequential extraction. (authors)

2003-10-03

374

Speciation of zinc in contaminated soils  

International Nuclear Information System (INIS)

The chemical speciation of zinc in soil solutions is critical to the understanding of its bioavailability and potential toxic effects. We studied the speciation of Zn in soil solution extracts from 66 contaminated soils representative of a wide range of field conditions in both North America and Europe. Within this dataset, we evaluated the links among the dissolved concentrations of zinc and the speciation of Zn2+, soil solution pH, total soil Zn, dissolved organic matter (DOM), soil organic matter (SOM) and the concentrations of different inorganic anions. The solid-liquid partitioning coefficient (Kd) for Zn ranged from 17 to 13,100 L kg-1 soil. The fraction of dissolved Zn bound to DOM varied from 60% to 98% and the soil solution free Zn2+ varied from 40% to 60% of the labile Zn. Multiple regression equations to predict free Zn2+, dissolved Zn and the solid-liquid partitioning of Zn are given for potential use in environmental fate modeling and risk assessment. The multiple regressions also highlight some of the most important soil properties controlling the solubility and chemical speciation of zinc in contaminated soils. - We studied the relationships among the chemical speciation of Zn in soil solution extracts from 66 contaminated soils and various physicochemical properties of the soils

2008-09-01

375

Analysis of the Life Cycle of the Soil Saprophyte Bacillus cereus in Liquid Soil Extract and in Soil‡  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Bacillus is commonly isolated from soils, with organisms of Bacillus cereus sensu lato being prevalent. Knowledge of the ecology of B. cereus and other Bacillus species in soil is far from complete. While the older literature favors a model of growth on soil-associated organic matter, the current paradigm is that B. cereus sensu lato germinates and grows in association with animals or plants, resulting in either symbiotic or pathogenic interactions. An in terra approach to study soil-associat...

2006-01-01

376

Remediation of lead contaminated soil  

International Nuclear Information System (INIS)

Lead contaminated soil in urban area is of major concern because of the potential health risk to children. Many studies have established a direct correlation between lead in soil and elevated blood lead levels in children. In Minneapolis, Minnesota, Mielke et al. (1983) reported that 50% of the Hmong children with lead poisioning were in areas where soil lead levels were between 500 and 1000 micrograms per gram (ug/g), and 40% of the children suffering from lead poisioning lived in areas where soil lead levels exceeded 1000 ug/g. In urban areas, lead pollution in soil has come from many different sources. The sources include lead paint, lead batteries and automobile exhaust. Olson and Skogerbee (1975) found the following lead compounds in soils where the primary source of pollution was from automobiles: lead sulfate, lead oxide, lead dioxide, lead sulfide, and metallic lead. The primary form of lead found was lead sulfate. Lead sulfate, lead tetraoxide, white lead, and other forms of lead have been used in the manufacture of paints for houses. At present, two remediation techniques, solidification and Bureau of Mines fluosilicic acid leaching, are available for lead-contaminated sites. The objective of the present investigation at the Risk Reduction Engineering Laboratory (RREL), Edison, was to try to solubilize the lead species by appropriate reagents and then recover the contaminants by precipitation as lead sulfate, using environmentally acceptable methods. The apparatus used for mixing was a LabMaster mixer, with variable speed and high-shear impeller. Previous work had used nitric acid for dissolving metallic lead. Owing to the environmental concerns, it was decided to use acetic acid in the presence of oxygen. The theoretical justification for this approach is the favorable redox potential for the reaction between metallic lead, acetic acid, and gaseous oxygen

1992-01-01

377

Soil, a sponge for pollutants  

International Nuclear Information System (INIS)

Soil has been regarded for a long time as an inert and closed medium where it was possible to dump any kind of hazardous wastes without implications on living organisms. But all pollutants entering the soil system can be stocked, transformed (often into more hazardous compounds) and transferred towards the atmosphere, groundwater and rivers. Obviously, the building up of toxic wastes into the soil system is a risk for all living beings. Pollution sources are numerous and diverse. They are given here into details. To follow the path of pollutants into the soil puzzle, with emphasis on the determination of bound residues, analytical experiments using labelled elements are by far the most efficient. But as a matter of fact, real toxicity can only be measured with biological tests, where living organisms such as light-emitting bacteria or plants are grown in contact with the toxic media. In order to minimize the diffusion of pollutants toward other natural media, a wide panel of remediation techniques are under development. Incineration and thermal desorption, for instance, are fast. Alternatively, the spreading of detergents onto the soil surface solubilizes pollutants that are later water-washed toward other media. Nonetheless, it is rarely complete and favors the migration of the pollutants toward groundwater, rivers and other ecosystems. On the other hand, mild, low-cost and efficient biological methods are now developing rapidly. Their principle lies on the natural ability of living organisms to extract and degrade toxic molecules. Lastly, plants may be used to remedy polluted soils, a process called ''phyto-remediation''. Its principles lies on two main phenomena. Firstly, some plant species are able to selectively extract large amounts of heavy metals from the ground then store them. Secondly, plants activate strongly the microbial biomass by injection of exudate enriched in organic nutriments in the root zone called ''rhizosphere''. Thus, the microbes, well-fed by the plant, degrade organic pollutants such as polycyclic aromatic hydrocarbons. (O.M.)

1997-01-01

378

Agromelioration of Saline Sodic Soils  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Agromelioration is the approach for reclamation of salt-affected soils in which minimum possible quantity of chemical amendments is applied coupled with organic material/agronomic practices. A field study was conducted to reclaim saline sodic soil through the application of gypsum @ 25 % G.R. alone and in combination with FYM, rice straw, sesbania @ 10 t ha G 1 and crust scraping. A standard treatment of 100 % G.R. was also included. Rice and wheat crops were grown in rotation for ...

Anwar Zaka, M.; Fakhar Mujeeb; Ghulam Sarwar; Hassan, N. M.; Hassan, G.

2003-01-01

379

Magnetic separation for soil decontamination  

International Nuclear Information System (INIS)

High gradient magnetic separation (HGMS) is a physical separation process that is used to extract magnetic particles from mixtures. The technology is used on a large scale in the kaolin clay industry to whiten or brighten kaolin clay and increase its value. Because all uranium and plutonium compounds are slightly magnetic, HGMS can be used to separate these contaminants from non-magnetic soils. A Cooperative Research and Development Agreement (CRADA) was signed in 1992 between Los Alamos National Laboratory (LANL) and Lockheed Environmental Systems and Technologies Company (LESAT) to develop HGMS for soil decontamination. This paper reports progress and describes the HGMS technology

1993-03-04

380

Determination of soil catalase potential  

Directory of Open Access Journals (Sweden)

Full Text Available In the present paper, it has been studied the catalatic potential of soils under the influence of sulfonilureic substances such as chlorsulfuron (20, 40, 100 g/ha, amidosulfuron (60, 120 and 300 g/ha and tifensulfuron (60, 120 and 300 g/ha. The studies were performed in field plots and also following laboratory models. The results of our determinations allowed us to conclude that all three substances and their applied doses had no relevant influence on catalase activity from soil.

Aurica Breica BOROZAN

2007-05-01

 
 
 
 
381

Soil health—a new challenge for microbiologists and chemists  

Digital Repository Infrastructure Vision for European Research (DRIVER)

[EN]: Soil health refers to the biological, chemical, and physical features of soil that are essential to long-term, sustainable agricultural productivity with minimal environmental impact. Thus, soil health provides an overall picture of soil

Arias Ferna?ndez, Mª E.; Gonza?lez-pe?rez, Jose? Antonio; Gonza?lez-vila, Francisco Javier; Ball, Andrew S.

2005-01-01

382

Prediction of soil depth using a soil-landscape regression model: a case study on forest soils in southern Taiwan.  

Science.gov (United States)

Techniques for conventional forest soil surveys in Taiwan need to be further developed in order to save time and money. Although some soil-landscape regression models have been developed to describe and predict soil properties and depths, they have seldom been studied in Taiwan. This study establishes linear soil-landscape regression models related to soil depths and landscape factors found in the forest soils of southern Taiwan. These models were evaluated by validating the models according to their mean errors and root mean square errors. The study was carried out at the 60,000 ha Chishan Forest Working Circle. About 310 soil pedons were collected. The landscape factors included elevation, slope, aspect, and surface stone contents. Sixty percent of the total field samples were used to establish the soil-landscape regression models, and forty % were used for validation. The sampling strategy indicated that each representative pedon covers an area of about 147 ha. The number of samples was appropriate considering the available time and budget. The single variate and/or multivariate linear regression soil-landscape models were successfully established. Those models revealed significant inter-relations among the soil depths of the B and B+BC horizons, solum thickness, and landscape factors, including slope and surface stone contents (p solum thickness without carrying out a field survey. Surface stone should be collected in a field soil survey to increase the precision of soil depth prediction of the B and B+BC horizons, and the solum thickness. PMID:11254170

Tsai, C C; Chen, Z S; Duh, C T; Horng, F W

2001-01-01

383

Saline soils spectral library as a tool for digital soil mapping  

Science.gov (United States)

Soil information is needed at regional to global scales for proper land management. Soil scientist has been historically interested in mapping soil classes and properties to represent and explore the spatial distribution of soil characteristics. Fortunately, soil mapping came into the digital era decades ago, enabling the dissemination of computationally intensive techniques (e.g., geostatistics). Digital soil mapping is moving forward in recent decades. Digital soil mapping has evolved from "traditional" studies that employed a set of soils to build soil maps, to more recent approaches that exploit the increasing computing facilities to combine soil databases with ancillary data such as digital elevation models, remote sensing imagery and proximal sensing datasets. The inclusion of VNIR spectroscopy in digital soil mapping approaches is an outstanding research field. VNIR spectroscopy has largely been employed to quantify soil properties with proximal sensor and remote sensor (i.e., imaging spectroscopy). One of the traditional problems in soil mapping is the time needed to compile a soil database large enough to allow for mapping with robustness. Therefore there is a growing interest in using the less time consuming, immutability of the sample and increasing accuracy of soil spectroscopy to obtain accurate enough soil maps but with lower data requirements. This research trend is particularly interesting for the study of highly dynamic soil processes for which is necessary to know the spatial and temporal changes of certain properties for a correct soil assessment. The objective of this work was the study of soil salinity which is a dynamic property responding to seasonal (i.e., vertical upwelling) and inter-annual (i.e., salinization) changes. Soil salinity is a major constraint for agriculture by limiting or excluding certain crops. Thus, a continuous monitoring of soil salinity is needed to select the most suitable crops and to prevent future salinization. Large arid and semiarid Mediterranean areas are affected by severe salinization processes by converging salinity problems due to parent material salinity, water scarcity and poor quality of irrigation water. A soils database in the South-East of Spain (semiarid Mediterranean environments) is being developed, by sampling and analyzing soils properties but especially salinity, besides recording their VNIR spectral signatures in field conditions. Also a spectral library related to soil type and salinity in these environments was determined in laboratory and it is a promising tool to monitor soil spectral signature changes. Positive relations between salinity, spectral data and soil type have been found using this technique. Soil spectra could be employed for quantitative spectroscopic analyses of soil properties, as ancillary data for digital soil mapping and for spectral calibration of remotely sensed imagery.

Bas, María Victoria; Meléndez-Pastor, Ignacio; Navarro-Pedreño, José; Gómez, Ignacio; Mataix-Solera, Jorge; Hernández, Encarni

2013-04-01

384

Soil science: Fungal friends against drought  

Science.gov (United States)

Fungal-based food webs of undisturbed grasslands resist and adapt to the effects of drought more than bacterial-based food webs of agricultural soils, indicating how soil biota might be able to withstand long-term climate change.

Six, Johan

2012-04-01

385

Extracting Quantitative Data From Lunar Soil Spectra.  

Science.gov (United States)

Using the modified Gaussian model (MGM) developed by Sunshine et al. we compared the spectral properties of the Lunar Soil Characterization Consortium (LSCC) suite of lunar soils with their petrologic and chemical compositions to obtain quantitative data....

S. K. Noble C. M. Pieters T. Hiroi

2005-01-01

386

Correspondence between the Soil Association and Defra  

Oct 5, 2004 ... required for adapting to the new standards on flock sizes and ... only where these \\are necessary to clarify what the standards mean .... This response is a unified \\response from both the So