WorldWideScience
 
 
1

Depleted soil carbon and nitrogen pools beneath impervious surfaces  

International Nuclear Information System (INIS)

Urban soils and vegetation contain large pools of carbon (C) and nitrogen (N) and may sequester these elements at considerable rates; however, there have been no systematic studies of the composition of soils beneath the impervious surfaces that dominate urban areas. This has made it impossible to reliably estimate the net impact of urbanization on terrestrial C and N pools. In this study, we compared open area and impervious-covered soils in New York City and found that the C and N content of the soil (0–15 cm) under impervious surfaces was 66% and 95% lower, respectively. Analysis of extracellular enzyme activities in the soils suggests that recalcitrant compounds dominate the organic matter pool under impervious surfaces. If the differences between impervious-covered and open area soils represent a loss of C and N from urban ecosystems, the magnitude of these losses could offset sequestration in other parts of the urban landscape. - The soils beneath impervious surfaces are depleted in C and N, which may have implications for the energy and nutrient balance of urban ecosystems.

2012-01-01

2

Percentage of Impervious Surface Soil as Indicator of Urbanization Impacts in Neotropical Aquatic Insects.  

UK PubMed Central (United Kingdom)

Several recent studies have shown a strong correlation between the area of impervious surface soil (IS) and the insect community structure from urban streams. This study assessed whether this relationship is observed in Neotropical streams. We examined if an increased IS reduces the diversity and simplifies the trophic structure of the community of Ephemeroptera, Plecoptera, and Trichoptera. An IS threshold was detected between 1.6 and 9.3%, in which there is a change in the community, both in taxonomic richness and trophic structure. Among the 27 genera identified, only 15 occurred in streams with IS?>?9%, while 24 genera were registered in streams with IS?

Fogaça FN; Gomes LC; Higuti J

2013-07-01

3

A comparison study of impervious surfaces estimation using optical and SAR remote sensing images  

Science.gov (United States)

The estimation of impervious surface area (ISA) is becoming increasingly important because of its environmental and socio-economic significance. However, accurate ISA estimation remains challenging due to the diversity of impervious materials, as well as the occurrence of clouds in subtropical humid areas. In order to address these challenges and provide an accurate estimation of ISA in cloudy areas, it is advantageous to use both optical and microwave remote sensing which can penetrate cloud coverage. Our study aims to conduct a comprehensive comparison between these two data sources and between different methods for mapping ISA. Both the classification results and accuracy assessment provide a better understanding about the differences between Landsat ETM+ and ENVISAT ASAR images and between artificial neural network (ANN) and support vector machine (SVM) classifier for estimating the impervious surfaces. The comparison demonstrates that ETM+ images alone provide a better ISA estimation (OA: about 90%; Kappa: about 0.88) than the estimation from ASAR images alone (OA: about 85%; Kappa: about 0.77). Additionally, the experiment indicates that SVM should be a better choice for ISA estimation using Landsat ETM+ images, while ANN turns out to be more sensitive to the confusion between dry soils and bright impervious surfaces, and between shade and dark impervious surfaces. For ENVISAR ASAR images, ANN gets a better result with higher accuracy, while the SVM classifier produces more noise and has some edge effects.

Zhang, Hongsheng; Zhang, Yuanzhi; Lin, Hui

2012-08-01

4

Estimating and Mapping Urban Impervious Surfaces: Reflection on Spectral, Spatial, and Temporal Resolutions  

Science.gov (United States)

Impervious surface is a key indicator of urban environmental quality and urbanization degree. Therefore, estimation and mapping of impervious surfaces in urban areas has attracted more and more attention recently by using remote sensing digital images. In this paper, satellite images with various spectral, spatial, and temporal resolutions are employed to examine the effects of these remote sensing data characteristics on mapping accuracy of urban impervious surfaces. The study area was the city proper of Indianapolis (Marion County), Indiana, United States. Linear spectral mixture analysis was applied to generate high albedo, low albedo, vegetation, and soil fraction images (endmembers) from the satellite images, and impervious surfaces were then estimated by adding high albedo and low albedo fraction images. A comparison of EO-1 ALI (multispectral) and Hyperion (hyperspectral) images indicates that the Hyperion image was more effective in discerning low albedo surface materials, especially the spectral bands in the mid-infrared region. Linear spectral mixing modeling was found more useful for medium spatial resolution images, such as Landsat TM/ETM+ and ASTER images, due to the existence of a large amount of mixed pixels in the urban areas. The model, however, may not be suitable for high spatial resolution images, such as IKONOS images, because of less influence from the mixing pixel. The shadow problem in the high spatial resolution images, caused by tall buildings and large tree crowns, is a challenge in impervious surface extraction. Alternative image processing algorithms such as decision tree classifier may be more appropriate to achieve high mapping accuracy. For mid-latitude cities, seasonal vegetation phenology has a significant effect on the spectral response of terrestrial features, and therefore, image analysis must take into account of this environmental characteristic. Three ASTER images, acquired on April 5, 2004, June 16, 2001, and October 3, 2000, respectively, were used to test the seasonal sensitivity of impervious surface estimation. Our results indicated that the summer (June) image was better than the spring (April) and the fall (October) ones. The summer image was most appropriate because there was full growth of vegetation, and mapping of impervious surfaces was more effective with contrasting spectral response from green vegetation. The mixing space, based on the four endmembers was perfectly three-dimensional. In contrast, there was significant amount of bare soils/grounds and non-photosynthesis vegetation in the spring and fall images. Plant phenology caused changes in the variance partitioning and impacted the mixing space characterization, leading to the difficulty in the estimation of impervious surfaces.

Weng, Q.

2007-12-01

5

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

Directory of Open Access Journals (Sweden)

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; P. J. M. Moreta

2008-01-01

6

Use of FGD as an impervious liner  

Energy Technology Data Exchange (ETDEWEB)

Increasing generation of coal combustion products (CCPs), particularly flue gas desulfurization (FGD) material, has led utilities to look for beneficial uses of these products. This paper presents one such utilization application of CCPs, i.e., the use of FGD material as an impervious liner for ponds and lagoons. The construction of a full scale lagoon using compacted FGD as a liner is presented. The project was undertaken primarily to address two critical questions, (1) what is the quality of water that permeates through an FGD liner and (2) what is the quantity of water permeating through a field compacted FGD fill of known thickness? The effects of construction processes on the behavior of compacted FGD are evaluated. The monitoring of the performance of the lagoon liner is discussed. Preliminary results indicate that the permeability of the field compacted FGD liner is reducing with time and is approaching the EPA recommended value of 1 x 10{sup {minus}7} cm/sec for waste containment facilities.

Wolfe, W.E.; Butalia, T.S.

1998-07-01

7

Detection of impervious surface change with multitemporal Landsat images in an urban-rural frontier.  

UK PubMed Central (United Kingdom)

Mapping and monitoring impervious surface dynamic change in a complex urban-rural frontier with medium or coarse spatial resolution images is a challenge due to the mixed pixel problem and the spectral confusion between impervious surfaces and other non-vegetation land covers. This research selected Lucas do Rio Verde County in Mato Grosso State, Brazil as a case study to improve impervious surface estimation performance by the integrated use of Landsat and QuickBird images and to monitor impervious surface change by analyzing the normalized multitemporal Landsat-derived fractional impervious surfaces. This research demonstrates the importance of two step calibrations. The first step is to calibrate the Landsat-derived fraction impervious surface values through the established regression model based on the QuickBird-derived impervious surface image in 2008. The second step is to conduct the normalization between the calibrated 2008 impervious surface image with other dates of impervious surface images. This research indicates that the per-pixel based method overestimates the impervious surface area in the urban-rural frontier by 50-60%. In order to accurately estimate impervious surface area, it is necessary to map the fractional impervious surface image and further calibrate the estimates with high spatial resolution images. Also normalization of the multitemporal fractional impervious surface images is needed to reduce the impacts from different environmental conditions, in order to effectively detect the impervious surface dynamic change in a complex urban-rural frontier. The procedure developed in this paper for mapping and monitoring impervious surface area is especially valuable in urban-rural frontiers where multitemporal Landsat images are difficult to be used for accurately extracting impervious surface features based on traditional per-pixel based classification methods as they cannot effectively handle the mixed pixel problem.

Lu D; Moran E; Hetrick S

2011-05-01

8

to characterize the impervious water storage with an urban surface-flux parameterization TERRA-MLU: evaluation and calibration for Toulouse city  

Science.gov (United States)

Evaporation from the urban impervious surface could have a considerable impact on the surface energy and moisture balance on rainy days. In particular, the ever increasing urbanization could alter the interaction between evaporation from the surface and precipitation within the urban climate (change) in the future. However, uncertainty exists within the determination of water storage parameters for the impervious surface, and hydrological parameters of the soil for the natural fraction in urban environments. In order to investigate the water balance over urban areas in more detail, TERRA-MLU, a new urban surface-flux parameterization, is applied over Toulouse city centre during the CAPITOUL campaign during 2004. The new urban parameterization covers a direct implementation of urban characteristics in TERRA_ML, Soil-Vegetation-Atmosphere Transfer model of COSMO. Besides anthropogenic heat, specific dynamic, radiative and thermal parameters including roughness length, heat capacity, conductivity, albedo and emissivity are assigned for the urban land-cover. A bluff-roughness thermal roughness length parametrization is used. New surface-layer transfer coefficients are adopted which can deal with very small thermal roughness lengths typical for urban surfaces. An new impervious water storage parameterization is introduced as well. TERRA-MLU is evaluated 'offline' for Marseille, Toulouse, Basel and Vancouver. Sensitivity analysis at the Toulouse site demonstrates that the maximum impervious water storage needs to be equal or less than 1kg/m2 if one only considers evaporation at a potential rate from the impervious surface. Furthermore, results are improved by implementing a storage form parameter that accounts for the reduction of evaporative surface fraction in case of small water content on the impervious surface. An offline sensitivity analysis is performed to estimate the maximum water storage and the storage form parameter. At last, it is found that the rooting depth of the vegetation needs to be described carefully in urban environments with large trees in order not to underestimate the latent heat during summer.

Wouters, Hendrik; Demuzere, Matthias; De Ridder, Koen; van Lipzig, Nicole; Vogel, Gerd

2013-04-01

9

Global Distribution and Density of Constructed Impervious Surfaces  

Directory of Open Access Journals (Sweden)

Full Text Available We present the first global inventory of the spatial distribution and density ofconstructed impervious surface area (ISA). Examples of ISA include roads, parking lots,buildings, driveways, sidewalks and other manmade surfaces. While high spatialresolution is required to observe these features, the new product reports the estimateddensity of ISA on a one-km2 grid based on two coarse resolution indicators of ISA – thebrightness of satellite observed nighttime lights and population count. The model wascalibrated using 30-meter resolution ISA of the USA from the U.S. Geological Survey.Nominally the product is for the years 2000-01 since both the nighttime lights andreference data are from those two years. We found that 1.05% of the United States landarea is impervious surface (83,337 km2) and 0.43 % of the world’s land surface (579,703km2) is constructed impervious surface. China has more ISA than any other country(87,182 km2), but has only 67 m2 of ISA per person, compared to 297 m2 per person in theUSA. The distribution of ISA in the world’s primary drainage basins indicates that watersheds damaged by ISA are primarily concentrated in the USA, Europe, Japan, China and India. The authors believe the next step for improving the product is to include reference ISA data from many more areas around the world.

Christopher D. Elvidge; Benjamin T. Tuttle; Paul C. Sutton; Kimberly E. Baugh; Ara T. Howard; Cristina Milesi; Budhendra Bhaduri; Ramakrishna Nemani

2007-01-01

10

Impact of Impervious Surface on River Discharge in Lake Kasumigaura Basin, Japan  

Science.gov (United States)

Impervious Surface Area (ISA) is defined as the constructed surface that prevents water from infiltrating into the soil. The ISA has emerged not only as an indicator of the degree of urbanization, but also as a major indicator of environmental quality for drainage basin management. This study focused on the relation between ISA ratio calculated by remote sensing technology and river discharge in Lake Kasumigaura Basin, Japan. ISA ratio was estimated by satellite image using Prescreened and Normalized Multiple Endmember Spectral Mixture Analysis (PNMESMA) developed for drainage basin with the estimating error smaller than 10%. Three types (vegetation, impervious surface, soil) of endmember were selected from the image, and the fraction of each endmember was calculated based on linear mixing model. River discharge dataset was collected from Kasumigaura River Office. Since the monitoring sites do not locate in the down stream, the up stream river basins of the monitoring sites were extracted by hydrological model in Geographic Information System (GIS) instead of the existing basin map. Digital Elevation Model (DEM) data with spatial resolution of 10m was collected from Geospatial Information Authority of Japan (GSI) to estimate the area of drainage. For the extracted drainage basins, the statistical relation between ISA ratio and river discharge were studied in 2000 and 2007 since the Landsat images used to estimate the fraction of ISA were in good image quality. The long-term change of river discharge was also investigated to provide the background value of this research. Results of spatial analysis suggested that the increase of the ISA raised the discharge in the rainy season, and reduced the discharge in the period of water shortage in Lake Kasumigaura Basin.

Yang, F.; Matsushita, B.; Fukushima, T.; Lab of Environmental Modeling; Creation

2011-12-01

11

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

Directory of Open Access Journals (Sweden)

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; Charles Antwi-Boasiako; Kwasi Frimpong-Mensah

2013-01-01

12

Prediction of stormwater particle loads from impervious urban surfaces based on a rainfall detachment index.  

Science.gov (United States)

This paper makes use of Non-Coarse Particle (NCP) data collected from three different impervious surfaces in Toowoomba, Australia. NCP is defined as suspended solids less than 500 microm in size. NCP loads (in mg/m(2)) were derived for 24 storms from a galvanized iron roof, a concrete car park and a bitumen road pavement. A scatter plot analysis was used to identify potential correlations between NCP loads and basic rainfall parameters such as rainfall depth and intensity. An exponential-type trend, consistent with many washoff models, was evident between load and average rainfall intensity for all surfaces. However, load data for some storms did not fit this general trend. Various indices, comprising different combinations of basic rainfall parameters, were evaluated as an alternative to rainfall intensity. A composite index, referred to as the Rainfall Detachment Index, was found to be better than average rainfall intensity in explaining a relationship between NCP load and storm rainfall characteristics. The selected rainfall index utilizes 6-minute rainfall intensities and is a variant of the well known Rainfall Erosivity Index (EI30) used for soil erosion estimation. PMID:17425071

Brodie, I M

2007-01-01

13

Prediction of stormwater particle loads from impervious urban surfaces based on a rainfall detachment index.  

UK PubMed Central (United Kingdom)

This paper makes use of Non-Coarse Particle (NCP) data collected from three different impervious surfaces in Toowoomba, Australia. NCP is defined as suspended solids less than 500 microm in size. NCP loads (in mg/m(2)) were derived for 24 storms from a galvanized iron roof, a concrete car park and a bitumen road pavement. A scatter plot analysis was used to identify potential correlations between NCP loads and basic rainfall parameters such as rainfall depth and intensity. An exponential-type trend, consistent with many washoff models, was evident between load and average rainfall intensity for all surfaces. However, load data for some storms did not fit this general trend. Various indices, comprising different combinations of basic rainfall parameters, were evaluated as an alternative to rainfall intensity. A composite index, referred to as the Rainfall Detachment Index, was found to be better than average rainfall intensity in explaining a relationship between NCP load and storm rainfall characteristics. The selected rainfall index utilizes 6-minute rainfall intensities and is a variant of the well known Rainfall Erosivity Index (EI30) used for soil erosion estimation.

Brodie IM

2007-01-01

14

Improving Distributed Runoff Prediction in Urbanized Catchments with Remote Sensing based Estimates of Impervious Surface Cover  

Directory of Open Access Journals (Sweden)

Full Text Available The amount and intensity of runoff on catchment scale are strongly determinedby the presence of impervious land-cover types, which are the predominant cover types inurbanized areas. This paper examines the impact of different methods for estimatingimpervious surface cover on the prediction of peak discharges, as determined by a fullydistributed rainfall-runoff model (WetSpa), for the upper part of the Woluwe Rivercatchment in the southeastern part of Brussels. The study shows that detailed informationon the spatial distribution of impervious surfaces, as obtained from remotely sensed data,produces substantially different estimates of peak discharges than traditional approachesbased on expert judgment of average imperviousness for different types of urban land use.The study also demonstrates that sub-pixel estimation of imperviousness may be a usefulalternative for more expensive high-resolution mapping for rainfall-runoff modelling atcatchment scale.

Jaroslaw Chormanski; Tim Van de Voorde; Tim De Roeck; Okke Batelaan; Frank Canters

2008-01-01

15

COMPREHENSIVE RESEARCH AND MANAGEMENT OF IMPERVIOUS SURFACE IMPACTS ON WATERSHED HYDROLOGY  

Science.gov (United States)

Impervious surface is one of the primary agents of hydrologic change in urbanizing watersheds, and its impacts on hydrologic cycles and terrestrial ecological regimes are multifold. The mechanisms through which these impacts are manifested are not well understood, hampering effec...

16

COMPREHENSIVE RESEARCH AND MANAGEMENT OF IMPERVIOUS SURFACES IMPACTS ON WATERSHED HYDROLOGY  

Science.gov (United States)

Impervious surface is one of the primary agents of hydrologic change in urbanizing watersheds, and its impacts on hydrologic cycles and terrestrial ecological regimes are multifold. The mechanisms through which these impacts are manifested are not well understood, hampering effec...

17

Identification and quantification of the hydrological impacts of imperviousness in urban catchments: a review.  

UK PubMed Central (United Kingdom)

Urbanisation produces numerous changes in the natural environments it replaces. The impacts include habitat fragmentation and changes to both the quality and quantity of the stormwater runoff, and result in changes to hydrological systems. This review integrates research in relatively diverse areas to examine how the impacts of urban imperviousness on hydrological systems can be quantified and modelled. It examines the nature of reported impacts of urbanisation on hydrological systems over four decades, including the effects of changes in imperviousness within catchments, and some inconsistencies in studies of the impacts of urbanisation. The distribution of imperviousness within urban areas is important in understanding the impacts of urbanisation and quantification requires detailed characterisation of urban areas. As a result most mapping of urban areas uses remote sensing techniques and this review examines a range of techniques using medium and high resolution imagery, including spectral unmixing. The third section examines the ways in which scientists and hydrological and environmental engineers model and quantify water flows in urban areas, the nature of hydrological models and methods for their calibration. The final section examines additional factors which influence the impact of impervious surfaces and some uncertainties that exist in current knowledge.

Jacobson CR

2011-06-01

18

Identification and quantification of the hydrological impacts of imperviousness in urban catchments: a review.  

Science.gov (United States)

Urbanisation produces numerous changes in the natural environments it replaces. The impacts include habitat fragmentation and changes to both the quality and quantity of the stormwater runoff, and result in changes to hydrological systems. This review integrates research in relatively diverse areas to examine how the impacts of urban imperviousness on hydrological systems can be quantified and modelled. It examines the nature of reported impacts of urbanisation on hydrological systems over four decades, including the effects of changes in imperviousness within catchments, and some inconsistencies in studies of the impacts of urbanisation. The distribution of imperviousness within urban areas is important in understanding the impacts of urbanisation and quantification requires detailed characterisation of urban areas. As a result most mapping of urban areas uses remote sensing techniques and this review examines a range of techniques using medium and high resolution imagery, including spectral unmixing. The third section examines the ways in which scientists and hydrological and environmental engineers model and quantify water flows in urban areas, the nature of hydrological models and methods for their calibration. The final section examines additional factors which influence the impact of impervious surfaces and some uncertainties that exist in current knowledge. PMID:21334133

Jacobson, Carol R

2011-02-18

19

COMPREHENSIVE RESEARCH AND IMPACTS OF MANAGEMENT OF IMPERVIOUSNESS ON WATERSHED HYDROLOGY  

Science.gov (United States)

Impervious surface is one of the primary agents of hydrologic change in urbanizing watersheds, and its impacts on hydrologic cycles and terrestrial ecological regimes are multifold. The mechanisms through which these impacts are manifested are not well understood, hampering effective management of ...

20

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 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.

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

2013-05-01

 
 
 
 
21

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; N.-J. Choi; A. R. Schmidt

2013-01-01

22

SSUIS - a research model for predicting suspended solids loads in stormwater runoff from urban impervious surfaces.  

Science.gov (United States)

Suspended solids from urban impervious surfaces (SSUIS) is a spreadsheet-based model that predicts the mass loading of suspended solids (SS) in stormwater runoff generated from impervious urban surfaces. The model is intended to be a research tool and incorporates several particle accumulation and washoff processes. Development of SSUIS is based on interpretation of storm event data obtained from a galvanised iron roof, a concrete car park and a bitumen road located in Toowoomba, Australia. SSUIS is a source area model that tracks the particle mass balance on the impervious surface and within its lateral drain to a point of discharge. Particles are separated into two groups: free and detained, depending on the rainfall energy required for surface washoff. Calibration and verification of SSUIS against the Toowoomba SS data yielded R(2) values ranging from 0.60 to 0.98. Parameter sensitivity analysis and an example of how SSUIS can be applied to predict the treatment efficiency of a grass swale are also provided. PMID:22643408

Brodie, Ian M

2012-01-01

23

SSUIS - a research model for predicting suspended solids loads in stormwater runoff from urban impervious surfaces.  

UK PubMed Central (United Kingdom)

Suspended solids from urban impervious surfaces (SSUIS) is a spreadsheet-based model that predicts the mass loading of suspended solids (SS) in stormwater runoff generated from impervious urban surfaces. The model is intended to be a research tool and incorporates several particle accumulation and washoff processes. Development of SSUIS is based on interpretation of storm event data obtained from a galvanised iron roof, a concrete car park and a bitumen road located in Toowoomba, Australia. SSUIS is a source area model that tracks the particle mass balance on the impervious surface and within its lateral drain to a point of discharge. Particles are separated into two groups: free and detained, depending on the rainfall energy required for surface washoff. Calibration and verification of SSUIS against the Toowoomba SS data yielded R(2) values ranging from 0.60 to 0.98. Parameter sensitivity analysis and an example of how SSUIS can be applied to predict the treatment efficiency of a grass swale are also provided.

Brodie IM

2012-01-01

24

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

25

Downscaling of thermal images over urban areas using the land surface temperature–impervious percentage relationship  

Science.gov (United States)

Intensive expansion and densification of urban areas decreases environmental quality and quality of urban life as exemplified by the urban heat island effect. For this reason, thermal information is becoming an increasingly important data source for integration in urban studies. It is expected that future spaceborne thermal sensors will provide data at appropriate spatial and temporal resolutions for urban studies. Until they become operational, research has to rely on downscaling algorithms increasing the spatial resolution of relatively coarse resolution thermal images albeit having a high temporal resolution. Existing downscaling algorithms, however, have been developed for sharpening images over rural and natural areas, resulting in large errors when applied to urban areas. The objective of this study is to adapt the DisTrad method for downscaling land surface temperature (LST) over urban areas using the relationship between LST and impervious percentage. The proposed approach is evaluated by sharpening aggregated LST derived from Landsat 7 ETM+ imagery collected over the city of Dublin on May 24th 2001. The new approach shows improved downscaling results over urban areas for all evaluated resolutions, especially in an environment with mixed land cover. The adapted DisTrad approach was most successful at a resolution of 480 m, resulting in a correlation of R2 = 0.84 with an observed image at the same resolution. Furthermore, sharpening using the adapted DisTrad approach was able to preserve the spatial autocorrelation present in urban environments. The unmixing performance of the adapted DisTrad approach improves with decreasing resolution due to the fact that the functional relationship between LST and impervious percentage was defined at coarse resolutions.

Essa, W.; van der Kwast, J.; Verbeiren, B.; Batelaan, O.

2013-08-01

26

Fabrication of gas impervious edge seal for a bipolar gas distribution assembly for use in a fuel cell  

International Nuclear Information System (INIS)

A process is described for the preparation of a bipolar gas reactant distribution assembly having solid, gas impervious edge seals to prevent leakage of gaseous reactants, which comprises providing a pair of porous plate members provided with peripheral slits, the slits being generally parallel to, and spaced from each of two edges of the plate, filling the slits with a non-porous, fusible gas impervious edge sealing compound, assembling the plate members with the slits therein approximately perpendicular to one another and a layer of fusible sealing material interposed therebetween, hot pressing the assembly at a temperature sufficient to cause a redistribution of the sealant layer into the pores of the adjacent plate surfaces and the edge sealing compound to flow and impregnate the region of the plates adjacent the slits and comingle with the redistributed sealant material to form a continuous layer of sealant along the edges of the assembly.

1986-01-01

27

Fabrication of gas impervious edge seal for a bipolar gas distribution assembly for use in a fuel cell  

Energy Technology Data Exchange (ETDEWEB)

A process is described for the preparation of a bipolar gas reactant distribution assembly having solid, gas impervious edge seals to prevent leakage of gaseous reactants, which comprises providing a pair of porous plate members provided with peripheral slits, the slits being generally parallel to, and spaced from each of two edges of the plate, filling the slits with a non-porous, fusible gas impervious edge sealing compound, assembling the plate members with the slits therein approximately perpendicular to one another and a layer of fusible sealing material interposed therebetween, hot pressing the assembly at a temperature sufficient to cause a redistribution of the sealant layer into the pores of the adjacent plate surfaces and the edge sealing compound to flow and impregnate the region of the plates adjacent the slits and comingle with the redistributed sealant material to form a continuous layer of sealant along the edges of the assembly.

Kaufman, A.; Werth, J.

1986-05-13

28

In vitro and in vivo characterization of an impervious polyester arterial prosthesis: the Gelseal Triaxial graft.  

UK PubMed Central (United Kingdom)

Over the years, textile polyester arterial prostheses have acquired an excellent reputation for easy handling and good healing characteristics. Until recently, the main drawback in using them was the need for preclotting. This, however, is no longer true. Nonporous polyester grafts which have been coated with an impervious bioerodible layer during manufacture are now commercially available. The Gelseal Triaxial prosthesis is one of this new generation of grafts. It is manufactured by impregnating a Triaxial prosthesis with a gelatin coating. An in vivo and in vitro evaluation of this new device has found that its water permeability is almost zero. It has good handling and conformability characteristics, and its bursting strength is slightly greater than that of the uncoated prosthesis due, no doubt, to the presence of the gel. The rates of degradation of the gelatin coating have proven to be rapid under both in vitro and in vivo conditions. In fact, only a few traces of the gel were found remaining on the graft after 2 wk in the canine thoracic aorta. In addition, this study has demonstrated that the use of a bioerodible gelatin coating, with its ability to promote cellular regeneration, is a feasible approach with which to achieve earlier and more complete biological healing.

Guidoin R; Marceau D; Rao TJ; King M; Merhi Y; Roy PE; Martin L; Duval M

1987-11-01

29

In vitro and in vivo characterization of an impervious polyester arterial prosthesis: the Gelseal Triaxial graft.  

Science.gov (United States)

Over the years, textile polyester arterial prostheses have acquired an excellent reputation for easy handling and good healing characteristics. Until recently, the main drawback in using them was the need for preclotting. This, however, is no longer true. Nonporous polyester grafts which have been coated with an impervious bioerodible layer during manufacture are now commercially available. The Gelseal Triaxial prosthesis is one of this new generation of grafts. It is manufactured by impregnating a Triaxial prosthesis with a gelatin coating. An in vivo and in vitro evaluation of this new device has found that its water permeability is almost zero. It has good handling and conformability characteristics, and its bursting strength is slightly greater than that of the uncoated prosthesis due, no doubt, to the presence of the gel. The rates of degradation of the gelatin coating have proven to be rapid under both in vitro and in vivo conditions. In fact, only a few traces of the gel were found remaining on the graft after 2 wk in the canine thoracic aorta. In addition, this study has demonstrated that the use of a bioerodible gelatin coating, with its ability to promote cellular regeneration, is a feasible approach with which to achieve earlier and more complete biological healing. PMID:3427141

Guidoin, R; Marceau, D; Rao, T J; King, M; Merhi, Y; Roy, P E; Martin, L; Duval, M

1987-11-01

30

Research on the impact of impervious surface area on urban heat island in Jiangsu Province  

Science.gov (United States)

Land surface temperature (LST), vegetation index, and other surface characteristics that obtained from remote sensing data have been widely used to describe urban heat island (UHI) phenomenon, but through impervious surface area (ISA) to describe the phenomenon has only used in a few study areas in our country. In a high urbanization and high population density region like Jiangsu Province, a wide range of extraction of ISA to study its relationship with UHI is less. In this paper, we use multi-temporal remote sensing images as data sources, and extract ISA from it in a large-scale by using decision tree classifier (DTC) and linear spectral mixture analysis (LSMA). Then combine the average surface temperature from the sixth band of Landsat TM by mono-window algorithm for spatial analysis, to assess the change of the urban heat island temperature amplitude and its relationship with the urban development density, size and ecological environment. Finally we use statistical methods to analyze the relationship between ISA, LST and UHI. The results show that ISA has a positive correlation with surface temperature. The ratio of ISA is higher and the difference value of the temperature is larger, thus the UHI will be more obvious.

Yang, Yingbao; Pan, Ping

2011-06-01

31

Mapping impervious surface area in the Brazilian Amazon using Landsat Imagery.  

UK PubMed Central (United Kingdom)

Impervious surface area (ISA) is an important parameter related to environmental change and socioeconomic conditions, and has been given increasing attention in the past two decades. However, mapping ISA using remote sensing data is still a challenge due to the variety and complexity of materials comprising ISA and the limitations of remote sensing data spectral and spatial resolution. This paper examines ISA mapping with Landsat Thematic Mapper (TM) images in urban and urban-rural landscapes in the Brazilian Amazon. A fractional-based method and a per-pixel based method were used to map ISA distribution, and their results were evaluated with QuickBird images based on the 2010 Brazilian census at the sector scale of analysis for examining the mapping performance. This research showed that the fraction-based method improved the ISA estimation, especially in urban-rural frontiers and in a landscape with a small urban extent. Large errors were mainly located at the sites having ISA proportions of 0.2-0.4 in a census sector. Calibration with high spatial resolution data is valuable for improving Landsat-based ISA estimates.

Li G; Lu D; Moran E; Hetrick S

2013-01-01

32

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

33

Soils  

International Nuclear Information System (INIS)

For Austria there exists a comprehensive soil data collection, integrated in a GIS (geographical information system). The content values of pollutants (cadmium, mercury, lead, copper, mercury, radio-cesium) are given in geographical charts and in tables by regions and by type of soil (forests, agriculture, greenland, others) for the whole area of Austria. Erosion effects are studied for the Austrian region. Legal regulations and measures for an effective soil protection, reduction of soil degradation and sustainable development in Austria and the European Union are discussed. (a.n.)

2001-01-01

34

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

35

Temporal mixture analysis for estimating impervious surface area from multi-temporal MODIS NDVI data in Japan  

Science.gov (United States)

As a proxy measure of the human ecological footprint, impervious surface area (ISA) has recently become a key concept in the field of urban remote sensing, with a focus on estimation of the ISA at a city-scale by using Landsat-style satellite images. However, ISA estimation is also in demand in disciplines such as the environmental assessment and policy making at a national scale. This paper proposes a new method for estimating the ISA fraction in Japan based on a temporal mixture analysis (TMA) technique. The required inputs for the proposed method are rearranged MODIS NDVI time-series datasets at the temporal stable zone (i.e., the first to the sixth largest NDVI values in a year). Three ISA distribution maps obtained from Landsat-5 TM data were used as reference maps to evaluate the performance of the proposed method. The results showed that the proposed TMA-based method achieved a large reduction in the effects of endmember variability compared with the previous methods (e.g., SMA and NSMA), and thus the new method has promising accuracy for estimating ISA in Japan. The overall root mean square error (RMSE) of the proposed method was 8.7%, with a coefficient of determination of 0.86, and there was no obvious underestimation or overestimation for the whole ISA range.

Yang, Fan; Matsushita, Bunkei; Fukushima, Takehiko; Yang, Wei

2012-08-01

36

Fabrication of gas impervious edge seal for a bipolar gas distribution assembly for use in a fuel cell  

Energy Technology Data Exchange (ETDEWEB)

A bipolar gas reactant distribution assembly for use in a fuel cell is disclosed, the assembly having a solid edge seal to prevent leakage of gaseous reactants wherein a pair of porous plates are provided with peripheral slits generally parallel to, and spaced apart from two edges of the plate, the slit being filled with a solid, fusible, gas impervious edge sealing compound. The plates are assembled with opposite faces adjacent one another with a layer of a fusible sealant material therebetween the slits in the individual plates being approximately perpendicular to one another. The plates are bonded to each other by the simultaneous application of heat and pressure to cause a redistribution of the sealant into the pores of the adjacent plate surfaces and to cause the edge sealing compound to flow and impregnate the region of the plates adjacent the slits and comingle with the sealant layer material to form a continuous layer of sealant along the edges of the assembled plates.

Kaufman, Arthur (West Orange, NJ); Werth, John (Princeton, NJ)

1986-01-01

37

Early electrophysiological indices of illusory contour processing within the lateral occipital complex are virtually impervious to manipulations of illusion strength.  

UK PubMed Central (United Kingdom)

The visual system can automatically interpolate or "fill-in" the boundaries of objects when inputs are fragmented or incomplete. A canonical class of visual stimuli known as illusory-contour (IC) stimuli has been extensively used to study this contour interpolation process. Visual evoked potential (VEP) studies have identified a neural signature of these boundary completion processes, the so-called IC-effect, which typically onsets at 90-110 ms and is generated within the lateral occipital complex (LOC). Here we set out to determine the delimiting factors of automatic boundary completion with the use of illusory contour stimuli and high-density scalp recordings of brain activity. Retinal eccentricity, ratio of real to illusory contours (i.e. support ratio), and inducer diameter were each varied parametrically, and any resulting effects on the amplitude and latency of the IC-effect were examined. Somewhat surprisingly, the amplitude of the IC-effect was found to be impervious to all changes in these stimulus parameters, manipulations that are known to impact perceived illusion strength. Thus, this automatic stage of object processing appears to be a binary process in which, so-long as minimal conditions are met, contours are automatically completed. At the same time, the latency of the IC-effect was found to vary inversely with support ratio, likely reflecting the additional time necessary to interpolate across the relatively longer induced boundaries of the implied object. These data are interpreted in the context of a two stage object-recognition model that parses processing into an early automatic perceptual stage that is followed by a more effortful conceptual processing stage.

Altschuler TS; Molholm S; Russo NN; Snyder AC; Brandwein AB; Blanco D; Foxe JJ

2012-02-01

38

Suitability of soil stabilized waste digestion pit  

Energy Technology Data Exchange (ETDEWEB)

The suitability of cement-stabilized soil as a construction material for the digestion pit of a bio-gas plant is reported. The pit was charged with cow-dung slurry and the rate of seepage loss as well as its stability was observed. It was found that the seepage rate decreased at a fast rate and the material became practically impervious in about ten days. As far as stability is concerned, no deterioration was observed after more than three years of continuous functioning. 13 refs.

Grewal, N.S.; Sagar, B.

1982-02-01

39

Soil clean up by in-situ aeration. II. Effects of impermeable caps, soil permeability, and evaporative cooling  

Energy Technology Data Exchange (ETDEWEB)

The clean up of soils contaminated by volatile compounds by in-situ vapor stripping was recently modeled by Wilson, Clarke, and Clarke. Their approach is modified to include the effects of a gas-impervious cap on the velocity field of the moving soil gas. Calculations indicate that such caps reduce the excessive flow of gas in the vicinity of the axis of the cylindrical volume of influence of a vent pipe, and they increase gas velocities near the periphery of the volume of influence. One thus expects use of impervious caps to improve the efficiency of in-situ soil vapor stripping: modeling of contaminant removal with such modified gas flow fields shows that this is indeed the case. Modeling of gas flow around buried obstacles indicates that there are not likely to interfere seriously with soil vapor stripping; some strategies are suggested to reduce their effects. The soil vapor stripping model is used to show that low soil permeabilities can be compensated for by increasing the radius of the stripping well packing. Evaporative cooling during vapor stripping is found to be insignificant under most circumstances.

Gannon, K.; Wilson, D.J. (Vanderbilt Univ., Nashville, TN (USA)); Clarke A.N.; Mutch, R.D. Jr.; Clarke, J.H. (Aware, Inc., Nashville, TN (USA))

1989-09-01

40

Estimativa de área impermeabilizada diretamente conectada e sua utilização como coeficiente de escoamento superficial Estimate of directly connected impervious areas and its use as runoff coefficient  

Directory of Open Access Journals (Sweden)

Full Text Available Neste estudo realizou-se a caracterização do uso e ocupação do solo na cidade de Ribeirão Preto (SP), além da análise detalhada da impermeabilização urbana e conectividade hidráulica dos lotes. Também foi avaliado o coeficiente de escoamento superficial (C) para seis sub-bacias, utilizando-se três métodos com diferentes níveis de precisão. Utilizando-se o Método Racional com os valores estimados de C, calcularam-se os picos de vazão para as sub-bacias. Identificou-se que a impermeabilização cresce com a redução da área do lote. As estimativas de C resultam em diferenças importantes em seus valores, refletindo na previsão da vazão. A utilização de tabelas com C detalhado e no seu limite superior se aproxima dos valores estimados por C AIDC. Recomenda-se estimar C AIDC a partir da área do lote ou pesquisa de campo.This paper presents a study of characterization of land occupation and its use in the city of Ribeirão Preto (São Paulo), as well as a detailed analysis of the urban imperviousness and hydraulic connectivity of the plots. The runoff coefficient (C) for siz sub-basins was evaluated on the basis of three different definitions. The peaks of outflow for the sub-basins were calculated using the Rational Method with the estimated values of C. It was identified that the imperviousness increases as the area of the plot decreases. The estimative of the C show important differences in its values, influencing the outflow. The use of tables with detailed and maximal C values beyond its superior limitation is equivalent to the values estimated with C DCIA. It is recommended that the C DCIA relative to the area be estimated based on the plot or field researches.

Leonardo Monteiro Garotti; Ademir Paceli Barbassa

2010-01-01

 
 
 
 
41

Estimativa de área impermeabilizada diretamente conectada e sua utilização como coeficiente de escoamento superficial/ Estimate of directly connected impervious areas and its use as runoff coefficient  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Neste estudo realizou-se a caracterização do uso e ocupação do solo na cidade de Ribeirão Preto (SP), além da análise detalhada da impermeabilização urbana e conectividade hidráulica dos lotes. Também foi avaliado o coeficiente de escoamento superficial (C) para seis sub-bacias, utilizando-se três métodos com diferentes níveis de precisão. Utilizando-se o Método Racional com os valores estimados de C, calcularam-se os picos de vazão para as sub-bacias. Id (more) entificou-se que a impermeabilização cresce com a redução da área do lote. As estimativas de C resultam em diferenças importantes em seus valores, refletindo na previsão da vazão. A utilização de tabelas com C detalhado e no seu limite superior se aproxima dos valores estimados por C AIDC. Recomenda-se estimar C AIDC a partir da área do lote ou pesquisa de campo. Abstract in english This paper presents a study of characterization of land occupation and its use in the city of Ribeirão Preto (São Paulo), as well as a detailed analysis of the urban imperviousness and hydraulic connectivity of the plots. The runoff coefficient (C) for siz sub-basins was evaluated on the basis of three different definitions. The peaks of outflow for the sub-basins were calculated using the Rational Method with the estimated values of C. It was identified that the imperv (more) iousness increases as the area of the plot decreases. The estimative of the C show important differences in its values, influencing the outflow. The use of tables with detailed and maximal C values beyond its superior limitation is equivalent to the values estimated with C DCIA. It is recommended that the C DCIA relative to the area be estimated based on the plot or field researches.

Garotti, Leonardo Monteiro; Barbassa, Ademir Paceli

2010-03-01

42

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?; Dragutin Petoši?; Frane Tomi?; Dragutin Dolanjski; Ivo Stri?evi?

2007-01-01

43

How well can calibrated Thornthwaite Mather models predict the variability in soil moisture observed in green infrastructure facilities?  

Science.gov (United States)

Soil moisture patterns influence hydrologic fluxes (infiltration/percolation, evapotranspiration, runoff) as well the biogeochemical processes (nutrient transformations, redox potential, etc), and ecosystem functions and services that depend on them. A new generation of urban water management practices (e.g. green infrastructure technologies) alter soil moisture patterns in potentially dramatic ways, for example by retrofitting soil media into and onto formerly impervious surfaces, and/or by routing impervious surface runoff to vegetated areas. However, the hydrologic models typically used to predict the impact of these new practices rarely track the soil moisture state. In this study, we use the Thornthwaite Mather (T/M) approach to simulate the variability in soil moisture observed in green roofs and urban tree pits. Soil moisture was monitored continuously at hourly time steps using Decagon soil moisture probes installed at three different depths in a green roof (for six months) and in a tree pit (for two months). Tipping bucket precipitation gages were also installed on each site. T/M models were constructed for each system, and calibrated separately to each of three different weeks of observations by adjusting the porosity, field capacity, and wilting point, as well as the mathmatical form of the soil moisture decay function until the lowest possible standard error was achieved. We present the variability in the best fit hydrologic properties derived from the three separate calibration exercises for each system. We then use the models to generate soil moisture time series over the entire periods of observation, and use this validation exercise to discuss the potential usefullness of the T/M approach in urban green infrastructure studies.

Yu, Z.; Digiovanni, K. A.; Montalto, F. A.

2010-12-01

44

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.

Yingbin Deng; Fenglei Fan; Renrong Chen

2012-01-01

45

Soil engineering  

CERN Multimedia

The agricultural world has changed significantly during the last years. The excessive use of heavy machinery, waste disposal, the use of agrochemicals and new soil cultivation means led to severe problems, which agricultural engineers have to cope with in order to prevent soil from permanent irreversible damage.This Soil Biology volume will update readers on several cutting-edge aspects of sustainable soil engineering including topics such as: soil compaction, soil density increases, soil disturbance and soil fragmentation; soil tillage machineries and optimization of tillage tools; soil traff

Dedousis, Athanasios P

2010-01-01

46

Gully Growth Patterns and Soil Loss under Rainfall at Urban Underground Drainage Construction Site, Uyo  

Directory of Open Access Journals (Sweden)

Full Text Available This study investigated, evaluated and modeled patterns of growth of gully morphometric dimension and soil loss volume under prevailing rainfall on the slopes of land graded for the construction of underground drainage at Uyo but delayed in completion. Land grading at underground (tunnel) drainage construction site rendered the exposed surface very impervious but young ephemeral gullies developed due to delays in completion. Data on gully morphometric dimension, soil loss and depth of rainfall were analyzed using SPSS ver. 17 statistical package. Mean gully growth in length, width and depth were different at 2.54±0.86, 0.923±0.29 and 0.41±0.11 m, respectively, yielding 3.87±0.08 m2 as mean volume of soil loss at full stage. Cubic polynomial was best-fit model for growth in length (R2 = 79%) and width (R2 = 69%) using weekly rainfall for an annual season. All gully sites had constant depth change, better predicted by quadratic (R2 = 13%) than linear (R2 = 9%) functions. Mean volume of soil loss per unit rainfall amount varied with low, medium and high rainfall amount and was highest at slope bottom (33 cm3/cm) and least at the crest (6.99 cm3/cm) with R2 = 38-34%. Land grading to impervious sublayer produced constant depth change in all gullies at the sites. The models for morphometric incremental growth and soil loss volume under the rainfall effect was significantly improved (p<0.05) by bifurcating the lumped annual curve into two growth periods in a year: the periods for increasing rainfall (from week 10-30) and for receding rainfall (from week 31-43) in a year and applying quadratic regressing functions on each (R2 = 91-99%). Rainfall was the principal gully factor and construction delays should be avoided.

O.E. Essien; I.A. Essen

2012-01-01

47

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; Daniele Peila

2010-01-01

48

SOIL - HEALTH RELATIONSHIPS: SOIL MICROBIOLOGY  

Science.gov (United States)

The dry soil of summer, mud in spring and fall, and frozen soil in winter do not appear to be living, but soil is overflowing with life. A healthy soil, one full of active microorganisms, is essential to agriculture. Healthy soil produces healthy plants efficient in the accumulation of nutrients, ...

49

Soil Liquefaction  

Science.gov (United States)

This tutorial provides general information on soil liquefaction, a hazard associated with earthquakes, for interested lay persons, and more detailed information for engineers. Topics include what soil liquefaction is, and when, where, and why it occurs. There are also suggestions for minimizing the risk of soil liquefaction, links to sites on soil liquefaction research, and links to sites on related topics.

50

Soil Science ????  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Soil Science satisfies the professional needs of all scientists and laboratory personnel involved in soil and plant research by publishing primary research reports and critical reviews of basic and applied soil science, especially as it relates to soil and plant studies and general environmen...

51

Soil Formation  

Science.gov (United States)

Humans use soil for their daily needs but do not sufficiently take account of its slow formation and fast loss. Discover the amazing geology of soil formation and the basic rock and soil types.Although soil seems the end product from weathering rocks, it is merely a stage in the gigantic cycle of mineral recycling by the movement of tectonic plates.

2008-07-24

52

Soil factors  

International Nuclear Information System (INIS)

[en] Progress is reported on the following research projects: effect of induced aggregation of soil materials on the chemical extractability of 90Sr and 147Pm contaminants; extractability of 238Pu and 242Cm from a contaminated soil as a function of pH and certain soil components; the determination of 238Pu and 242Cm in aqueous soil extracts; and liquid scintillation counting procedure for plutonium in soil extracts

1976-01-01

53

Evaluation of soil lead contamination at former firing ranges on Governors Island, New York  

Energy Technology Data Exchange (ETDEWEB)

Hundreds of former firing ranges used to discharge small caliber arms are located at military bases slated for closure throughout the United States. This paper discusses some of the issues and challenges associated with sampling, analysis, and remediation of two US Coast Guard former firing ranges located on Governors Island, New York. The collection of representative and homogeneous soil samples is difficult because of the random distribution of bullets at former firing range sites. Lead concentrations in the soil at Governors Island varied from 10 milligrams per kilogram (mg/kg) to over 50,000 mg/kg. Impacts to ground water are typically minimal because these metals are not highly mobile in the surficial soils where they accumulate and soil pH concentrations are not acidic enough to induce downward mobility. The evaluation and selection of appropriate remedial alternative(s) and clean-up concentrations should consider the historical and future use of the military base. Decisions on base closure and future land use at Fort Jay should dictate the selection of the appropriate remedial solutions for the former firing ranges. Remedial options evaluated include simple control measures (e.g. fencing, impervious cover), soil stabilization and soil removal.

Mehan, D.G.; Martin, B.A. [Daniel, Mann, Johnson and Mendenhall, Arlington, VA (United States); Gavini, B.G. [Coast Guard, Governors Island, NY (United States)

1995-12-31

54

Brown ground: a soil carbon analogue for the green world hypothesis?  

UK PubMed Central (United Kingdom)

For many decades, ecologists have asked what prevents herbivores from consuming most of the plant biomass in terrestrial ecosystems, or "Why is the world green?" Here I ask the analogous question for detritivores: what prevents them from degrading most of the organic material in soils, or "Why is the ground brown?" For fresh plant detritus, constraints on decomposition closely parallel constraints on herbivory: both herbivore and decomposer populations may be controlled by plant tissue chemistry from the bottom up and predators from the top down. However, the majority of soil carbon is not plant litter but carbon that has been consumed by detritivores and reprocessed into humic compounds with complex and random chemical structures. This carbon persists mainly because the chemical properties of humic compounds and interactions with soil minerals constrain decomposition by extracellular enzymes in soil. Other constraints on decomposers, such as nutrient limitation of enzyme production and competition with opportunistic microbes, also contribute to brown ground. Ultimately, the oldest soil carbon persists via transformation into complex molecules that are impervious to enzymatic attack and effectively decoupled from processing by the soil food web.

Allison SD

2006-05-01

55

Brown ground: a soil carbon analogue for the green world hypothesis?  

Science.gov (United States)

For many decades, ecologists have asked what prevents herbivores from consuming most of the plant biomass in terrestrial ecosystems, or "Why is the world green?" Here I ask the analogous question for detritivores: what prevents them from degrading most of the organic material in soils, or "Why is the ground brown?" For fresh plant detritus, constraints on decomposition closely parallel constraints on herbivory: both herbivore and decomposer populations may be controlled by plant tissue chemistry from the bottom up and predators from the top down. However, the majority of soil carbon is not plant litter but carbon that has been consumed by detritivores and reprocessed into humic compounds with complex and random chemical structures. This carbon persists mainly because the chemical properties of humic compounds and interactions with soil minerals constrain decomposition by extracellular enzymes in soil. Other constraints on decomposers, such as nutrient limitation of enzyme production and competition with opportunistic microbes, also contribute to brown ground. Ultimately, the oldest soil carbon persists via transformation into complex molecules that are impervious to enzymatic attack and effectively decoupled from processing by the soil food web. PMID:16671007

Allison, Steven D

2006-03-23

56

Solarization soil  

International Nuclear Information System (INIS)

[en] Solar energy could be used in pest control, in soil sterilization technology. The technique consists of covering humid soils by plastic films steadily fixed to the soil. Timing must be in summer during 4-8 weeks, where soil temperature increases to degrees high enough to control pests or to produce biological and chemical changes. The technique could be applied on many pests soil, mainly fungi, bacteria, nematods, weeds and pest insects. The technique could be used in greenhouses as well as in plastic film covers or in orchards where plastic films present double benefits: soil sterilization and production of black mulch. Mechanism of soil solarization is explained. Results show that soil solarization can be used in pest control after fruit crops cultivation and could be a method for an integrated pest control. 9 refs

1995-10-18

57

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

International Nuclear Information System (INIS)

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 10-8 to 10-1 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.

1997-01-01

58

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

59

Characterization of Selenium Pollution in the Western United States by Coupling Soil Moisture with Geochemical Transport  

Science.gov (United States)

Due to the arid conditions of the Western United States, selenium released from sandstone and shale hillslopes is transported by overland runoff and is shown to cause fish and aquatic bird death and reproductive failure. Precipitation in contact with exposed seleniferous soils, carry dissolved and particulate forms of selenium in runoff and groundwater to the valley floor to be redistributed throughout the hillslope and alluvial fan. Impervious clay soils and the arid climate impede the flushing of selenium below the groundwater table so that selenium is continually cycled in the alluvial fan. A physically based model that couples hydrologic land surface interactions and geochemical transport based on soil moisture was developed to characterize the loading, transport, and distribution of selenium. The soil moisture distribution and overland flow patterns determined by the hydrologic model for the watershed are factors that control soil chemical movement and transformation. The main geochemical and physical transport mechanisms of selenite and selenate, dissolution from soil, speciation, adsorption, advection, and mass transfer from pore water to overland form, are characterized as functions of surface flow and the soil moisture of the fifteen centimeter deep soil layer for each model grid. The movement of overland flow within each grid is routed to the outlet of the watershed. Flow patterns and measured selenium concentrations at two sites; the Panoche/ Silver Creek watershed in Central California, and the Leach Creek watershed in Colorado, are compared to model results. Selenium pollution characterization at a watershed scale will add to the understanding of the cycling of selenium within and across watersheds and aid in the mitigation of selenium pollution.

Zhao, M.; Liang, X.; Guo, J.

2004-12-01

60

Soil treatment  

UK PubMed Central (United Kingdom)

Two heretofore bothersome waste products, namely sewage sludge ash and water treatment lime, are mixed together to provide an agricultural soil treatment enhancing the nutrient value and raising the pH of the soil for improved plant growth while simultaneously minimizing the risk of wind blown ash dust. The ash is readily dryable and dusty but this feature is obscured by the water treatment lime which has a tendency to retain water. Mixing of tonnage quantities is conducted at a site near the facility generating the ash; and the mixture is transported to the agricultural soil to be treated and applied at a quantity between 2 and 70 tons of the water-containing mixture per acre of the soil. The application quantity is sufficient to raise the level of the soil-water pH of acid soil to a value of at least 6.5 but not above about 7.5 and insufficient to add to the soil more than the governmental limits for several heavy metals. Many nutrients needed for plant growth are contained in the mixture.

REHBEIN GERALD L; MONTAIN PAUL D

 
 
 
 
61

Soil engineering  

CERN Document Server

This book has been designed as a manual which present an incisive look into the engineering principles of soil testing, design and remediation techniques which are increasingly being used in soil conservation practice. The text attempts to acquaint readers with the essentials of the subject even as it elaborates upon the challenges, issues and concerns associated with it, relating particularly to the care of various types of soils, and how they respond to the numerous technology designed to improve their quality, texture and fertility. In addition to listing current trends and developments in

Reddy, R N

2010-01-01

62

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.

Meor Othman Hamzah; Zul Fahmi Mohamed Jaafar; Fauziah Ahmad

2011-01-01

63

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.

64

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.

65

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 di...

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

66

Soil mechanics  

CERN Multimedia

Knowledge of the behavior of soil mechanics is essential for forecasting the internal displacements and actions of any construction. This book, although theoretical at first glance, also offers a more practical scope, giving readers adequate tools to plan geotechnical projects correctly.

Nova, Roberto

2012-01-01

67

Soil microbiology  

International Nuclear Information System (INIS)

The major areas of soil microbiological and biochemical research which have involved both stable and radioactive isotopes are summarized. These include microbial decomposition of naturally occurring materials, microbial biomass, interactions of plants and microbes, denitrification, mineralization and immobilization of nitrogen and biological nitrogen fixation. (U.K.).

1984-01-01

68

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

69

The Twelve Soil Orders - Soil Taxonomy  

Science.gov (United States)

This University of Idaho website discusses the twelve orders of soils, and provides images that illustrate the distribution, properties, and use of the soil orders. It provides general information on each of the twelve orders with a description, a U.S. map showing soil locations, and pictures of the soil type. A Global Distribution Map indicates locations of each soil type throughout the world.

70

Soil fracturing cracks soil remediation barriers  

Energy Technology Data Exchange (ETDEWEB)

Remediating contaminants from clays, silts and other low-permeability soils always has been a challenge for environmental specialists. Such soils pose a paradox for cleanup professionals: although the soils' inherent low permeability greatly limits the rate and extent of contaminant movement, this characteristic also makes them especially difficult to remediate. Groundwater extraction and treatment, as well as soil-vapor extraction systems, are ineffective on low-permeability soils, even after years of operation. One technology alternative some remediation specialists are investigating is hydraulic fracturing. The first step in any soil fracturing operation to enhance remediation is characterizing the nature and extent of contamination, as well as the soil's geotechnical properties. Hydraulic fracturing essentially is a controlled failure of the soil mass, which is governed by existing stresses on the soil, the soil's strength or cohesion, and the nature of its discontinuities or structure. The design of soil fracturing programs also must consider the remediation method intended for a site. Soil fracturing alone is only an enabling technology to enhance the movement of fluids into and out of a soil mass. Contamination of the unsaturated zone with volatile organic compounds commonly is remediated using soil-vapor extraction with enhanced microbial degradation of the contaminants. Groundwater contamination may require extraction and treatment. In such applications, the fracturing program is designed to provide interconnections between natural discontinuities in the soil mass, as these are the channels along which water and contaminants travel.

Baker, E. (Golder Applied Technologies Inc., Atlanta, GA (United States)); Leach, B. (Golder Associates, Calgary, Alberta (Canada). Hydraulic Fracturing Group)

1995-03-01

71

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; MOHAMMED FAIZAN; DEVASHISH PANDEY SIDDHARTH; REHANJOT SINGH

2013-01-01

72

Applied Soil Ecology ???????  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Applied Soil Ecology addresses the role of soil organisms and their interactions in relation to: agricultural productivity, nutrient cycling and other soil processes, the maintenance of soil structure and fertility, the impact of human activities and xenobiotics on soil ecosystems and bio(tec...

73

Soil Science & Plant Nutrition ?????????  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Soil Science & Plant Nutrition is the official English journal of the Japanese Society of Soil Science and Plant Nutrition (JSSSPN), and publishes original research and reviews in soil physics, chemistry and mineralogy; soil biology; plant nutrition; soil genesis; classification and survey; s...

74

DEVELOPING WEED SUPPRESSIVE SOILS THROUGH IMPROVED SOIL QUALITY MANAGEMENT  

Science.gov (United States)

Sustainable agriculture is based in part on efficient management of soil microorganisms for improving soil quality. However, identification of biological indicators of soil quality for predicting weed suppression in soils has received little attention. We investigated differences in soil microbial ...

75

NOrth AMerica Soil (NOAM-SOIL) Database  

Science.gov (United States)

NOAM-SOIL is being created by combining the CONUS-SOIL database with pedon data and soil geographic data coverages from Canada and Mexico. Completion of the in-progress NOrth AMerica Soil (NOAM-SOIL) database will provide complete North America coverage comparable to CONUS. Canadian pedons, which number more than 500, have been painstakingly transcribed to a common format, from hardcopy, and key- entered. These data, along with map unit polygons from the 1:1,000,000 Soil Landscapes of Canada, will be used to create the required spatial data coverages. The Mexico data utilizes the INEGI 1:1,000,000 scale soil map that was digitized by U. S. Geological Survey EROS Data Center in the mid 1990's plus about 20,000 pedons. The pedon data were published on the reverse side of the paper 1:250,000 scale Soil Map of Mexico and key entered by USDA and georeferenced by Penn State to develop an attribute database that can be linked to the 1:1,000,000 scale Soil Map of Mexico based on taxonomic information and geographic proximity. The essential properties that will be included in the NOAM-SOIL data base are: layer thickness (depth to bedrock or reported soil depth); available water capacity; sand, silt, clay; rock fragment volume; and bulk density. For quality assurance purposes, Canadian and Mexican soil scientists will provide peer review of the work. The NOAM-SOIL project will provide a standard reference dataset of soil properties for use at 1km resolution by NACP modelers for all of North America. All data resources, including metadata and selected raw data, will be provided through the Penn State web site: Soil Information for Environmental Modeling and Ecosystem Management (www.soilinfo.psu.edu). Progress on database completion is reported.

Miller, D. A.; Waltman, S. W.; Geng, X.; James, D.; Hernandez, L.

2009-05-01

76

Soil organic matter mineralization in frozen soils  

Science.gov (United States)

Boreal forest soils are frozen for a large part of the year and soil organic matter mineralization during this period has been shown to significantly influence the C balance of boreal forest ecosystems. Mineralization proceeds through heterotrophic microbial activity, but the understanding of the environmental controls regulating soil organic matter mineralization under frozen conditions is poor. Through a series of investigations we have addressed this issue in order to elucidate to what extent a range of environmental factors control mineralization processes in frozen soils and also the microbial communities potential to oxidize organic substrates and grow under such conditions. The unfrozen water content in the frozen soils was shown to be an integral control on the temperature response of biogenic CO2 production across the freezing point of bulk soil water. We found that osmotic potential was an important contributor to the total water potential and, hence, the unfrozen water content of frozen soil. From being low and negligible in an unfrozen soil, the osmotic potential was found to contribute up to 70% of the total water potential in frozen soil, greatly influencing the volume of liquid water. The specific factors of how soil organic matter composition affected the unfrozen water content and CO2 production of frozen soil were studied by CP-MAS NMR. We concluded that abundance of aromatics and recalcitrant compounds showed a significant positive correlation with unfrozen water content and these were also the major soil organic fractions that similarly correlated with the microbial CO2 production of the frozen soils. Thus, the hierarchy of environmental factors controlling SOM mineralization changes as soils freeze and environmental controls elucidated from studies of unfrozen systems can not be added on frozen conditions. We have also investigated the potential activity of soil microbial communities under frozen conditions in order to elucidate temperature limitations on soil organic matter mineralization. The carbon mineralization was found to proceed down to -4°C and the soil microbial communities were growing at this temperature. At -9°C, the carbon mineralization was insignificant. 13C NMR revealed that the soil microorganisms were able to produce ethylene glycol (anti-freeze medium) under frozen conditions (-4°C). The production of ethylene glycol coincided with an increase in CO2 production that took place after a lag-phase of ca. 41 days. 13C NMR also confirmed that soil microbial anabolic processes continued under frozen conditions. At -4°C, 23% of the used substrate was respired as CO2 and 77% were converted and assimilated by the organisms as e.g. lipids and polysaccharides. This is contradicting to earlier studies that suggest that mainly processes yielding CO2 occurs in soils at <0°C.

Harrysson Drotz, S.; Sparrman, T.; Schleucher, J.; Nilsson, M.; Öquist, M. G.

2009-12-01

77

MILESTONES IN SOIL PHYSICS  

Science.gov (United States)

This special issue of “Soil Science“ celebrates the enormous accomplishments made during the past century or more in the field of soil science, including some of the key articles published in Soil Science during its 90 years of existence. In this article, we focus on the contributions in soil physic...

78

Soils of Eastern Siberia.  

Science.gov (United States)

Contents: The mountain-taiga soils of eastern Transbaikalia; Contribution to the study of soils on the tundras of northern Yakutia; Weathering and soil formation on granite in the tundra zone; Description of Arctic-tundra soils on Bol'shoi Lyakhovskii I. ...

E. N. Ivanova

1969-01-01

79

Soil organic matter studies  

International Nuclear Information System (INIS)

The use of isotopes in soil organic matter studies is reviewed. Such studies include measuring the input of organic carbon into soils, the decomposition of isotope-labelled materials such as organic compounds and microbial and plant material in soils, the characterization of soil organic matter and the availability of nutrients released from organic residues. (U.K.).

1984-01-01

80

Soil water management  

International Nuclear Information System (INIS)

The use of radiation and tracer techniques in investigations into soil water management in agriculture, hydrology etc. is described. These techniques include 1) neutron moisture gauges to monitor soil water content and soil water properties, 2) gamma radiation attenuation for measuring the total density of soil and soil water content, 3) beta radiation attenuation for measuring changes in the water status of crop plants and 4) radioactive and stable tracers for identifying pathways, reactions and retention times of the constituents in soils and groundwater aquifers. The number and spacing of soil observations that should be taken to represent the management unit are also considered. (U.K.).

1984-01-01

 
 
 
 
81

Soil physical properties affecting soil erosion in tropical soils  

International Nuclear Information System (INIS)

[en] 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

2004-01-01

82

Soil stabilization 1982  

Science.gov (United States)

Seven papers cover the following areas: design, construction and performance of lime, fly ash, and slag pavement; evaluation of heavily loaded cement stabilized bases; coal refuse and fly ash compositions; potential highway base course materials; lime soil mixture design considerations for soils of southeastern United States; short term active soil property changes caused by injection of lime and fly ash; soil cement for use in stream channel grade stabilization structures; and reaction products of lime treated southeastern soils.

Barenberg, E. J.; Thompson, M. R.; Tayabji, S. D.; Nussbaum, P. J.; Ciolko, A. T.

83

Mass Transport within Soils  

Energy Technology Data Exchange (ETDEWEB)

Contaminants in soil can impact human health and the environment through a complex web of interactions. Soils exist where the atmosphere, hydrosphere, geosphere, and biosphere converge. Soil is the thin outer zone of the earth's crust that supports rooted plants and is the product of climate and living organisms acting on rock. A true soil is a mixture of air, water, mineral, and organic components. The relative proportions of these components determine the value of the soil for agricultural and for other human uses. These proportions also determine, to a large extent, how a substance added to soil is transported and/or transformed within the soil (Spositio, 2004). In mass-balance models, soil compartments play a major role, functioning both as reservoirs and as the principal media for transport among air, vegetation, surface water, deeper soil, and ground water (Mackay, 2001). Quantifying the mass transport of chemicals within soil and between soil and atmosphere is important for understanding the role soil plays in controlling fate, transport, and exposure to multimedia pollutants. Soils are characteristically heterogeneous. A trench dug into soil typically reveals several horizontal layers having different colors and textures. As illustrated in Figure 1, these multiple layers are often divided into three major horizons: (1) the A horizon, which encompasses the root zone and contains a high concentration of organic matter; (2) the B horizon, which is unsaturated, lies below the roots of most plants, and contains a much lower organic carbon content; and (3) the C horizon, which is the unsaturated zone of weathered parent rock consisting of bedrock, alluvial material, glacial material, and/or soil of an earlier geological period. Below these three horizons lies the saturated zone - a zone that encompasses the area below ground surface in which all interconnected openings within the geologic media are completely filled with water. Similarly to the unsaturated zone with three major horizons, the saturated zone can be further divided into other zones based on hydraulic and geologic conditions. Wetland soils are a special and important class in which near-saturation conditions exist most of the time. When a contaminant is added to or formed in a soil column, there are several mechanisms by which it can be dispersed, transported out of the soil column to other parts of the environment, destroyed, or transformed into some other species. Thus, to evaluate or manage any contaminant introduced to the soil column, one must determine whether and how that substance will (1) remain or accumulate within the soil column, (2) be transported by dispersion or advection within the soil column, (3) be physically, chemically, or biologically transformed within the soil (i.e., by hydrolysis, oxidation, etc.), or (4) be transported out of the soil column to another part of the environment through a cross-media transfer (i.e., volatilization, runoff, ground water infiltration, etc.). These competing processes impact the fate of physical, chemical, or biological contaminants found in soils. In order to capture these mechanisms in mass transfer models, we must develop mass-transfer coefficients (MTCs) specific to soil layers. That is the goal of this chapter. The reader is referred to other chapters in this Handbook that address related transport processes, namely Chapter 13 on bioturbation, Chapter 15 on transport in near-surface geological formations, and Chapter 17 on soil resuspention. This chapter addresses the following issues: the nature of soil pollution, composition of soil, transport processes and transport parameters in soil, transformation processes in soil, mass-balance models, and MTCs in soils. We show that to address vertical heterogeneity in soils in is necessary to define a characteristic scaling depth and use this to establish process-based expressions for soil MTCs. The scaling depth in soil and the corresponding MTCs depend strongly on (1) the composition of the soil and physical state of the soil, (2) the chemical and p

McKone, Thomas E.

2009-03-01

84

Modelling with transparent soils  

CERN Document Server

The fundamental premise of this monograph is that transparent synthetic materials with geotechnical properties similar to those of natural soils can be used to study 3-D deformation and flow problems in natural soils. Transparent soils can be made by matching the refractive index of synthetic soil materials and the pore fluid. This monographs presents the geotechnical behaviour of several families of transparent soils that can be combined to meet model-test requirements, in terms of strength, deformation, or permeability ""Modelling with Transparent Soils"" demonstrates how an optical system c

Iskander, Magued

2010-01-01

85

Eurasian Soil Science ??????  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Eurasian Soil Science publishes original research papers on global and regional studies discussing both theoretical and experimental problems of genesis, geography, physics, chemistry, biology, fertility, management, conservation, and remediation of soils. Special sections are devoted to curr...

86

Soil Biology & Biochemistry ??????????  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Soil Biology & Biochemistry publishes original and scientifically challenging research articles and short communications that present new findings and their possible applications. The ecology and biochemical activities of soil organisms and their effects on the environment and plant growth ar...

87

What is Soil Liquefaction?  

Science.gov (United States)

This reference explains the phenomenon of soil liquefaction, a common cause of damage to man-made structures that occurs during earthquakes. Students can read an explanation of how the water in wet soils exerts a pressure on the soil particles that influences how tightly the particles themselves are pressed together, causing the soil to lose strength. The text is accompanied by animations that show the phenomenon in action.

88

Soil Litter: Temperate Zones  

Science.gov (United States)

This two-minute radio program focuses on why temperate soils harbor more biodiversity than do tropical soils. The guest on the program, a soil biologist, explains that cooler temperatures and large-scale disturbances have promoted the evolution of more soil-dwelling species in temperate areas. The program, part of the Pulse of the Planet radio show, is available here in text and audio formats. Copyright 2005 Eisenhower National Clearinghouse

Planet, Pulse O.

2006-06-23

89

Soil & Tillage Research ???????  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Soil & Tillage Research is concerned with the changes in the physical, chemical and biological parameters of the soil environment brought about by soil tillage and field traffic, their effects on both below and above ground environmental quality, crop establishment, root development and plant...

90

ISRIC - World Soil Information  

Digital Repository Infrastructure Vision for European Research (DRIVER)

ISRICWorld Soil Information is an independent foundation, funded by the Netherlands Government with a mandate to increase knowledge of the land, its soils in particular, and to support the sustainable use of land resources; in short, to help people understand soils. Its aims are to -Inform and educa...

Dent, D.L.

91

SOIL WATER HYSTERESIS  

Science.gov (United States)

Since at least the early work of Haines, it has been recognized that volumetric soil water content, W, and hydraulic conductivity, K, are not singular functions of soil water pressure head, h, but rather exhibit considerable variation depending on the wetting and drying history of the soil. The non-...

92

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

93

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.

94

Experimental unsaturated soil mechanics  

CERN Multimedia

In this general report, experimental systems and procedures of investigating the hydro-mechanical behaviour of unsaturated soils are presented. The water retention properties of unsaturated soils are commented and linked to various physical parameters and properties of the soils. Techniques of controlling suction are described together with their adaptation in various laboratory testing devices. Some typical features of the mechanical behaviour of unsaturated soils are presented within an elasto-plastic framework. An attempt to describe the numerous and significant recent advances in the investigation of the behaviour of unsaturated soils, including the contributions to this Conference, is proposed.

Delage, Pierre

2008-01-01

95

Liquefaction of soils  

Energy Technology Data Exchange (ETDEWEB)

Liquefaction during earthquakes has been a significant cause of failure of onshore as well as offshore structures. The phenomenon of liquefaction has been studied extensibly for the case of cohesionless soils. Fine grained soils such as silts and sands with fines have generally been considered as non-liquefiable in the past. Recent studies have shown that fine grained soils in certain situations may be susceptible to liquefaction. This paper will present a brief review of the recent work on the liquefaction of fine grained soils and the results of an investigation conducted by the authors on liquefaction behavior of silty soils.

Puri, V.K. [Southern Illinois Univ., Carbondale, IL (United States); Prakash, S.; Kumar, S. [Univ. of Missouri, Rolla, MO (United States)

1995-12-31

96

Introduction to soil mechanics  

CERN Multimedia

Introduction to Soil Mechanics covers the basic principles of soil mechanics, illustrating why the properties of soil are important, the techniques used to understand and characterise soil behaviour and how that knowledge is then applied in construction.   The authors have endeavoured to define and discuss the principles and concepts concisely, providing clear, detailed explanations, and a well-illustrated text with diagrams, charts, graphs and tables. With many practical, worked examples and end-of-chapter problems and coverage of Eurocode 7, Introduction to Soil Mechanics is

Bodo, Bela

2013-01-01

97

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; R. Alimardani and A. Sharifi

2010-01-01

98

A computer model for predicting two-phase ground water transport in the soil surrounding a growing melt in the in situ vitrification process  

International Nuclear Information System (INIS)

Two different computer models are tested for their usefulness in predicting the water balance and pressure field surrounding a growing hemispherical In Situ Vitrification (ISV) melt. The melt is centered under the flat surface of a hemisphere of soil contained by an impervious wall. The control volume method is employed for balancing heat, and mass in each model. The soil is considered a porous media; consequently, fluid velocity can be modeled by Darcy's equation. Both computer models employ grids which adapt to the transient boundary of the growing melt. Computational Grid I (CGI) adapts with the melt boundary by contracting in the radial direction only. In addition to adapting to the melt boundary, Computational Grid II (CGII) also adapts to the liquid-vapor interface which moves outward from the 1,700 C melt in response to the formation of Vapor. CGII has been devised in order to attempt to reduce, at a reasonable CPU cost, the numerical pressure oscillation which arises when the grid is too coarse. A very fine CGI is used as a benchmark to test CGII and a coarser version of CGI. Results from the two CGI and the one CGII cases are presented graphically to illustrate the mass flux of liquid and vapor water and the build-up in pressure as the melt boundary approaches the impermeable wall.

1996-01-01

99

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.

Stępniewska Z.; Gliński J.; Włodarczyk T.; Brzezińska M.; Blum W.E.H.; Rampazzo N.; Wimmer B.

1997-01-01

100

European Journal of Soil Biology ?????????  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The European Journal of Soil Biology covers all aspects of fundamental and applied soil biology relating to soil microbial and faunal ecology, and processes promoted by soil organisms. Soils from managed and natural ecosystems of biomes worldwide are of interest, and the Journal is open to su...

 
 
 
 
101

Building Soils for Better Crops. Sustainable Soil Management. Third Edition.  

Science.gov (United States)

With the new emphasis on sustainable agriculture comes a reawakening of interest in soil health. Early scientists, farmers, and gardeners were well aware of the importance of soil quality and organic matter to the productivity of soil. The significance of...

F. Magdoff H. Van Es

2009-01-01

102

Multi-step soil washing to remove contaminants from soil  

Energy Technology Data Exchange (ETDEWEB)

The advantage of the soil washing approach to remove contaminants from soils is discussed. This report also describes 2 cases in which uranium and plutonium are dispersed in soils. Removal efficiencies are described.

Skriba, M.C.

1993-12-31

103

Earthworms and Soil Pollutants  

Science.gov (United States)

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.

Hirano, Takeshi; Tamae, Kazuyoshi

2011-01-01

104

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.

Takeshi Hirano; Kazuyoshi Tamae

2011-01-01

105

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.

106

Soil treatment composition  

UK PubMed Central (United Kingdom)

Two nuisance waste products, namely sewage sludge ash and water treatment lime, are mixed together to provide an agricultural soil treatment composition which enhances the nutrient value and raises the pH of the soil for improved plant growth while simultaneously minimizing the risk of wind blown ash dust.

REHBEIN GERALD L; MONTAIN PAUL D

107

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

108

Soil and vegetation surveillance  

Energy Technology Data Exchange (ETDEWEB)

Soil sampling and analysis evaluates long-term contamination trends and monitors environmental radionuclide inventories. This section of the 1994 Hanford Site Environmental Report summarizes the soil and vegetation surveillance programs which were conducted during 1994. Vegetation surveillance is conducted offsite to monitor atmospheric deposition of radioactive materials in areas not under cultivation and onsite at locations adjacent to potential sources of radioactivity.

Antonio, E.J.

1995-06-01

109

Soil seed banks  

Directory of Open Access Journals (Sweden)

Full Text Available The goal of this literature review is to discuss some of the major aspects of the soil seed bank, from its characteristics down to methodological aspects of its determination. Soil seed bank is the reservoir of viable seeds or of vegetative propagules that are present in the soil and that are able to recompose a natural vegetation. In the agroecossystems the soil seed bank is related to weeds, and the knowledge of its size and composition in terms of species can be used in the prediction of future infestations, to built simulation models of population establishment through time and also the definition of soil and cultural management programs, in order to have a rational use of herbicides.

Christoffoleti P.J.; Caetano R.S.X.

1998-01-01

110

Soil working implement  

UK PubMed Central (United Kingdom)

A soil working implement is of the kind having a support frame 13 on which at least one soil working tool 10 is mounted, the tool being preferably of the kind having a tool portion 34 passing edgewise through the ground at an angle to the vertical. The tool portion 34 has a soil-engaging surface 51 which is inclined at an acute angle to the direction of travel A so that, with the tool 10 offset to one side of the line of action X of the frame, forces tending to generate a turning moment in the horizontal plane are counteracted by engagement of the soil by the inclined soil-engaging surface 51. Additionally or alternatively the support frame 13 may be adjusted to angle the tool 10 relative to the direction of travel.

Linger Barry Anthony

111

Soil Classification Using GATree  

CERN Document Server

This paper details the application of a genetic programming framework for classification of decision tree of Soil data to classify soil texture. The database contains measurements of soil profile data. We have applied GATree for generating classification decision tree. GATree is a decision tree builder that is based on Genetic Algorithms (GAs). The idea behind it is rather simple but powerful. Instead of using statistic metrics that are biased towards specific trees we use a more flexible, global metric of tree quality that try to optimize accuracy and size. GATree offers some unique features not to be found in any other tree inducers while at the same time it can produce better results for many difficult problems. Experimental results are presented which illustrate the performance of generating best decision tree for classifying soil texture for soil data set.

Bhargavi, P

2010-01-01

112

Soil Classification Using GATREE  

Directory of Open Access Journals (Sweden)

Full Text Available This paper details the application of a genetic programming framework forclassification of decision tree of Soil data to classify soil texture. The database containsmeasurements of soil profile data. We have applied GATree for generating classificationdecision tree. GATree is a decision tree builder that is based on Genetic Algorithms(GAs). The idea behind it is rather simple but powerful. Instead of using statistic metricsthat are biased towards specific trees we use a more flexible, global metric of tree qualitythat try to optimize accuracy and size. GATree offers some unique features not to befound in any other tree inducers while at the same time it can produce better results formany difficult problems. Experimental results are presented which illustrate theperformance of generating best decision tree for classifying soil texture for soil data set.

P.Bhargavi; Dr.S.Jyothi

2010-01-01

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

Soil bacteria for remediation of polluted soils  

International Nuclear Information System (INIS)

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

1996-09-18

115

[Soil biota and its role in soil ecology  

UK PubMed Central (United Kingdom)

Soil organisms alter soil physical, chemical and biological properties in different ways. The composition and structure of biotic communities at one hierarchical level can influence the spatial heterogeneity of resource at other hierarchical levels, and the latter is supported by a number of biologically relevant spheres-functional domains in soil. In this paper, the role of soil biota in soil ecosystem processes was assessed, and the relationship between soil biodiversity and ecosystem function was presented. Soil ecosystem responses to global change were also discussed.

Liang W; Wen D

2001-02-01

116

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 Tag 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)

1996-01-01

117

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

118

Remediating munitions contaminated soils  

Energy Technology Data Exchange (ETDEWEB)

The former Nebraska Ordnance Plant (NOP) at Mead, NE was a military loading, assembling, and packing facility that produced bombs, boosters and shells during World War II and the Korean War (1942-1945, 1950-1956). Ordnances were loaded with 2,4,6-trinitrotoluene (TNT), amatol (TNT and NH{sub 4}NO{sub 3}), tritonal (TNT and Al) and Composition B (hexahydro-1,3,5-trinitro-1,3,5-triazine [RDX] and TNT). Process waste waters were discharged into wash pits and drainage ditches. Soils within and surrounding these areas are contaminated with TNT, RDX and related compounds. A continuous core to 300 cm depth obtained from an NOP drainage ditch revealed high concentrations of TNT in the soil profile and substantial amounts of monoamino reduction products, 4-amino-2,6-dinitrotoluene (4ADNT) and 2-amino-4,6-dinitrotoluene (2ADNT). Surface soil contained TNT in excess of 5000 mg kg{sup -1} and is believed to contain solid phase TNT. This is supported by measuring soil solution concentrations at various soil to solution ratios (1:2 to 1:9) and obtaining similar TNT concentrations (43 and 80 mg L{sup -1}). Remediating munitions-contaminated soil at the NOP and elsewhere is of vital interest since many of the contaminants are carcinogenic, mutagenic or otherwise toxic to humans and the environment. Incineration, the most demonstrated remediation technology for munitions-containing soils, is costly and often unacceptable to the public. Chemical and biological remediation offer potentially cost-effective and more environmentally acceptable alternatives. Our research objectives are to: (a) characterize the processes affecting the transport and fate of munitions in highly contaminated soil; (b) identify effective chemical and biological treatments to degrade and detoxify residues; and (c) integrate these approaches for effective and practical remediation of soil contaminated with TNT, RDX, and other munitions residues.

Shea, P.J.; Comfort, S.D. [Univ. of Nebraska, Lincoln, NE (United States)

1995-10-01

119

Managing compost stability and amendment to soil to enhance soil heating during soil solarization.  

Science.gov (United States)

Soil solarization is a method of soil heating used to eradicate plant pathogens and weeds that involves passive solar heating of moist soil mulched (covered) with clear plastic tarp. Various types of organic matter may be incorporated into soil prior to solarization to increase biocidal activity of the treatment process. Microbial activity associated with the decomposition of soil organic matter may increase temperatures during solarization, potentially enhancing solarization efficacy. However, the level of organic matter decomposition (stability) necessary for increasing soil temperature is not well characterized, nor is it known if various amendments render the soil phytotoxic to crops following solarization. Laboratory studies and a field trial were performed to determine heat generation in soil amended with compost during solarization. Respiration was measured in amended soil samples prior to and following solarization as a function of soil depth. Additionally, phytotoxicity was estimated through measurement of germination and early growth of lettuce seedlings in greenhouse assays. Amendment of soil with 10%(g/g) compost containing 16.9 mg CO2/gdry weight organic carbon resulted in soil temperatures that were 2-4 °C higher than soil alone. Approximately 85% of total organic carbon within the amended soil was exhausted during 22 days of solarization. There was no significant difference in residual respiration with soil depth down to 17.4 cm. Although freshly amended soil proved highly inhibitory to lettuce seed germination and seedling growth, phytotoxicity was not detected in solarized amended soil after 22 days of field solarization. PMID:23422041

Simmons, Christopher W; Guo, Hongyun; Claypool, Joshua T; Marshall, Megan N; Perano, Kristen M; Stapleton, James J; Vandergheynst, Jean S

2013-02-17

120

Managing compost stability and amendment to soil to enhance soil heating during soil solarization.  

UK PubMed Central (United Kingdom)

Soil solarization is a method of soil heating used to eradicate plant pathogens and weeds that involves passive solar heating of moist soil mulched (covered) with clear plastic tarp. Various types of organic matter may be incorporated into soil prior to solarization to increase biocidal activity of the treatment process. Microbial activity associated with the decomposition of soil organic matter may increase temperatures during solarization, potentially enhancing solarization efficacy. However, the level of organic matter decomposition (stability) necessary for increasing soil temperature is not well characterized, nor is it known if various amendments render the soil phytotoxic to crops following solarization. Laboratory studies and a field trial were performed to determine heat generation in soil amended with compost during solarization. Respiration was measured in amended soil samples prior to and following solarization as a function of soil depth. Additionally, phytotoxicity was estimated through measurement of germination and early growth of lettuce seedlings in greenhouse assays. Amendment of soil with 10%(g/g) compost containing 16.9 mg CO2/gdry weight organic carbon resulted in soil temperatures that were 2-4 °C higher than soil alone. Approximately 85% of total organic carbon within the amended soil was exhausted during 22 days of solarization. There was no significant difference in residual respiration with soil depth down to 17.4 cm. Although freshly amended soil proved highly inhibitory to lettuce seed germination and seedling growth, phytotoxicity was not detected in solarized amended soil after 22 days of field solarization.

Simmons CW; Guo H; Claypool JT; Marshall MN; Perano KM; Stapleton JJ; Vandergheynst JS

2013-05-01

 
 
 
 
121

Aeolian sandy soil modifier  

UK PubMed Central (United Kingdom)

The invention relates to an aeolian sandy soil modifier. The modifier is prepared by mixing and fermenting cow droppings, corn straws, furfural residues, sheep droppings, CO(NH2)2 and NH4H2PO4 according to air drying weight proportion of 5500-6500:6000-7000:4500-5500:7000-8000:90-110:90-110. By using agricultural organic solid wastes, the invention effectively improves water retention and fertility preservation abilities of the aeolian sandy soil and increases organic matters and the contents of rapidly active N, P and K in the aeolian sandy soil.

HUILONG LI; HUIPING PEI; JIAHAI QIN; LIHUA QIU; PEITANG WANG; ZHANWEN XIAO; ZHIBIN YAN

122

Apparatus for treating soil  

UK PubMed Central (United Kingdom)

Apparatus for treating the soil of a grass playing field that includes a piping system containing perforated pipe lines seated in a distribution bed beneath the soil of the playing field. A blower having a discharge port and a suction port is selectively connected to the duct networks to either pump air upwardly or draw air downwardly through the soil profile. A separator is connected in the air supply line of the system for removing water from the air stream moving between the blower and the duct network. The removed water is collected in a holding tank for recycling, or disposed of in an environmentally safe manner.

BENSON WILLIAM M

123

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

124

Rehabilitation and soil characterization  

Energy Technology Data Exchange (ETDEWEB)

Less than 3% of the surface area of South Africa is disturbed by mining, but the impact on this area is significant. A survey shows that poor vegetation cover on rehabilitated land is frequently due to compaction of mine soil and the presence of soil acidity. The physical and chemical properties of rehabilitated land are described. A grading system used at the Ingwe Coal Corporation collieries to assess rehabilitation performance is described. The system uses a 5-point scale to grade land according to landscape quality and soil fertility. 11 refs., 3 figs., 5 tabs.

Limpitlaw, D.; Aken, M.; Kilani, J.; Mentis, M.; Nell, J.P.; Tanner, P.D. [University of Witwatersrand, Witwatersrand (South Africa)

1997-09-01

125

Canadian Journal of Soil Science ?????????  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Canadian Journal of Soil Science is an international peer-reviewed journal published in cooperation with the Canadian Society of Soil Science. The journal publishes original research on the use, management, structure and development of soils and draws from the disciplines of soil science, agr...

126

Remediation of radioactive contaminated soils  

Energy Technology Data Exchange (ETDEWEB)

Distribution of radionuclides in Republic of Belarus` soils after Chernobyl NPP accident has been investigated. Different methods of soils cleaning from radionuclides and effectiveness of these methods in the conditions of large-scale contamination were examined. Cutting and localizing of soil upper layer were shown to be the most effective method for decreasing the soil radioactive contamination level.

Bondar, Y.I.; Tsariov, A.V.; Shmanai, G.S. [Academy of Sciences Belarus, Minsk (Belarus). Inst. of Radiobiology

1995-12-31

127

SCALING METHODS IN SOIL PHYSICS  

Science.gov (United States)

Soil physical properties are needed to understand and manage natural systems spanning an extremely wide range of scales. Much of soil data are obtained from small soil samples and cores, monoliths, or small field plots, yet the goal is to reconstruct soil physical properties across fields, watershed...

128

HOW SOIL FORMING PROCESSES DETERMINE SOIL-BASED VITICULTURAL ZONING  

Directory of Open Access Journals (Sweden)

Full Text Available The aim of this study was to elucidate the soil forming processes of representative vineyard soils, and to discuss the implications on a soil-based viticultural zoning at very detailed scale. The study area is located in Priorat, Penedes and Conca de Barbera viticultural areas (Catalonia, North-eastern Spain). The studied soils belong to representative soil map units determined at 1:5,000 scale, according to Soil Taxonomy classification. The soil forming processes, identified through morphological and micromorphological analyses, have significant effects on some soil properties. For example, the different processes of clay accumulation in soils developed from granodiorites in Priorat or gravel deposits in Conca de Barbera, are primarily responsible for significant differences in clay content, available water capacity and cation exchange capacity. These soils properties, especially those related to soil moisture regime, have a direct influence on vineyard management and grape quality. However, soil forming processes are not always reflected on soil classification, especially in soils modified by man. We show that climate or geology alone cannot be used in viticultural zoning at very detailed scale, unless soil forming processes are taken into account.

J.M Ubalde; X Sort; R.M Poch

2011-01-01

129

HOW SOIL FORMING PROCESSES DETERMINE SOIL-BASED VITICULTURAL ZONING  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english The aim of this study was to elucidate the soil forming processes of representative vineyard soils, and to discuss the implications on a soil-based viticultural zoning at very detailed scale. The study area is located in Priorat, Penedes and Conca de Barbera viticultural areas (Catalonia, North-eastern Spain). The studied soils belong to representative soil map units determined at 1:5,000 scale, according to Soil Taxonomy classification. The soil forming processes, identi (more) fied through morphological and micromorphological analyses, have significant effects on some soil properties. For example, the different processes of clay accumulation in soils developed from granodiorites in Priorat or gravel deposits in Conca de Barbera, are primarily responsible for significant differences in clay content, available water capacity and cation exchange capacity. These soils properties, especially those related to soil moisture regime, have a direct influence on vineyard management and grape quality. However, soil forming processes are not always reflected on soil classification, especially in soils modified by man. We show that climate or geology alone cannot be used in viticultural zoning at very detailed scale, unless soil forming processes are taken into account.

Ubalde, J.M; Sort, X; Poch, R.M

2011-01-01

130

Airborne soil concentrations  

International Nuclear Information System (INIS)

Airborne soil concentrations downwind of an isolated field were measured during one dust storm. Concentration increased as the friction velocity increased, but the increase was a function of particle diameter

1978-01-01

131

soil organic matter fractionation  

Science.gov (United States)

Carbon is essential for plant growth, due to its effects on other soil properties like aggregation. Knowledge of dynamics of organic matter in different locations in the soil matrix can provide valuable information which affects carbon sequestration and soil the other soil properties. Extraction of soil organic matter (SOM) fractions has been a long standing approach to elucidating the roles of soil organic matter in soil processes. Several kind fractionation methods are used and all provide information on soil organic matter function. Physical fractionation capture the effects on SOM dynamics of the spatial arrangement of primary and secondary organomineral particles in soil while chemical fractionation can not consider the spatial arrangement but their organic fractions are suitable for advanced chemical characterization. Three method of physical separation of soil have been used, sieving, sedimentation and densitometry. The distribution of organic matter within physical fractions of the soil can be assessed by sieving. Sieving separates soil particles based strictly on size. The study area is located on north central Iran, between 35° 41'- 36° 01' N and 50° 42'- 51° 14' E. Mean annual precipitation about 243.8 mm and mean annual air temperature is about 14.95 °C. The soil moisture and temperature regime vary between aridic-thermic in lower altitudes to xeric-mesic in upper altitudes. More than 36 surface soil samples (0-20 cm) were collected according to land-use map units. After preliminary analyzing of samples 10 samples were selected for further analyses in five size fractions and three different time intervals in September, January and April 2008. Fractionation carried out by dry sieving in five classes, 1-2 mm, 0.5-1 mm, 270 ?m-0.5mm, 53-270 ?m and <53 ?m. Organic matter and C/N ratio were determined for all fractions at different time intervals. Chemical fractionation of organic matter also carried out according to Tan (2003), also Mineralogical studies were carried out to illustrate the relationship between clay mineral series and organic matter. According to the results the amount of organic carbon increases by decreasing size fractions and reaches to its maximum in <250? classes, also 2:1 and expanding clays which have the ability to maintain larger amounts of organic carbon were the dominant clay minerals. Chemical fractionation of soil organic matter to humic acid and fulvic acid shows that there is a better correlation between humic acid contents and soil organic matter (R2 = 0.86) than fulvic acid and organic matter (R2=0.5). The amount of humic and fulvic acids varies in different size fractions and reaches to its minimum in the E fraction in all three stages. The relationships between fulvic and humic acids with organic matter content, demonstrating that at the lower organic matter content, humification is slow, thus humic acid content is rather low than the fulvic acid content. By increasing the organic matter content biological activity increases and followed by humification process proceeds so that the humic acid content locates over the fulvic acid content.

Osat, Maryam; Heidari, Ahmad

2010-05-01

132

Attenuation coefficients of soils  

International Nuclear Information System (INIS)

[en] As a prerequisite to the interpretation of gamma-spectrometric in situ measurements of activity concentrations of soil radionuclides the attenuation of 60 to 1332 keV gamma radiation by soil samples varying in water content and density has been investigated. A useful empirical equation could be set up to describe the dependence of the mass attenuation coefficient upon photon energy for soil with a mean water content of 10%, with the results comparing well with data in the literature. The mean density of soil in the GDR was estimated at 1.6 g/cm3. This value was used to derive the linear attenuation coefficients, their range of variation being 10%. 7 figs., 5 tabs. (author)

1989-01-01

133

CLEAN - Soil, Air, Water ??????????  

Digital Repository Infrastructure Vision for European Research (DRIVER)

CLEAN - Soil, Air, Water is a new, international and interdisciplinary journal covering all aspects of Sustainability and Environmental Safety. It hosts an attractive mixture of peer-reviewed scientific reviews, research papers, and short communications. Combining environmental aspects of soi...

134

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

135

Recovering metals from soil  

UK PubMed Central (United Kingdom)

The invention relates to recovering metals, such as nickel and cobalt, by phytomining or phytoextracting soils rich in metals wherein the desired metal is selectively accumulated in hyperaccumulator plants by adjusting the soil pH. The metals are ultimately recovered from above-ground plant tissues at economically acceptable levels without further contaminating the metal-containing sites. The invention also relates to metal-hyperaccumulating plants.

CHANEY RUFUS L; ANGLE J. SCOTT; LI YIN-MING; BAKER ALAN J.M

136

RECOVERING METALS FROM SOIL  

UK PubMed Central (United Kingdom)

The invention relates to recovering metals, such as nickel and cobalt, by phytomining or phytoextracting soils rich in metals wherein the desired metal is selectively accumulated in hyperaccumulator plants by adjusting the soil pH. The metals are ultimately recovered from above-ground plant tissues at economically acceptable levels without further contaminating the metal-containing sites. The invention also relates to metal-hyperaccumulating plants.

CHANEY Rufus L.; ANGLE Jay Scott; LI Yin-Ming; BAKER Alan J. M.

137

Soil working machine  

UK PubMed Central (United Kingdom)

Soil working machine for agriculture The machine facilitates working the soil. It has a number of rotating cultivation tools, and has a holder section (1) with the end sides (2) of the holder (4) for the tool carrier (T) each at least against its longitudinal sides (12,13). There are holder grips (3) passing through the holding section. They are aligned across the longitudinal sides of the holder section.

Warnking Richard Dipl.-Ing.

138

Impact of soil hydraulic parameter uncertainty on soil moisture modeling  

Science.gov (United States)

For simulations in basins where soil information is limited to soil type maps, a methodology is presented to quantify the uncertainty of soil hydraulic parameters arising from within-soil-class variability and to assess the impact of this uncertainty on soil moisture modeling. Continuous pedotransfer functions were applied to samples with different texture within each soil class to construct discrete probability distributions of the soil hydraulic parameters. When propagating the parameter distributions through a hydrologic model, a wide range of simulated soil moisture was generated within a single soil class. The pedotransfer function was found to play a crucial role in assessing the uncertainty in the modeled soil moisture, and the geographic origin of the pedotransfer function (region specific versus nonregion specific) highly affected the range and shape of the probability distribution of the soil hydraulic parameters. Furthermore, the modeled soil moisture distribution was found to be non-Gaussian. An accurate uncertainty assessment therefore requires the characterization of its higher-order moments. As an extension of this research, we have shown that applying continuous region-specific pedotransfer functions to the central point of a soil class is a better alternative to standard (often nonregion-specific) class pedotransfer functions for determining an average set of soil hydraulic parameters.

Loosvelt, Lien; Pauwels, Valentijn R. N.; Cornelis, Wim M.; de Lannoy, GabriëLle J. M.; Verhoest, Niko E. C.

2011-03-01

139

Soil cultivation for enhanced wastewater infiltration in soil aquifer treatment (SAT)  

Science.gov (United States)

Infiltrating TWW induces pond soil surface water repellency and reduced infiltration. The accumulation of organic matter on the soil surface layer induces water repellency. Soil cultivation at the ponds reduced organic matter content at the soil profile. Soil cultivation at the ponds drastically reduced soil water repellency. Soil cultivation increased TWW infiltration into the soil in comparison to no cultivation.

Nadav, Itamar; Tarchitzky, Jorge; Chen, Yona

2012-11-01

140

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

 
 
 
 
141

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; Stella Lovelli; Mariana Amato; Michele Perniola

2011-01-01

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; Stella Lovelli; Mariana Amato; Michele Perniola

2009-01-01

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.

Teodoro Di Tommaso; Stella Lovelli; Mariana Amato; Michele Perniola

144

Soil mechanics and analysis of soils overlying cavitose bedrock  

International Nuclear Information System (INIS)

[en] The stability of the residual soils existing at the West Chestnut Ridge Site, Oak Ridge Reservation, Tennessee, was evaluated. The weathered bedrock below this residual soil contains numerous solution cavities, and several karst features were identified. The West Chestnut Ridge site was evaluated with respect to deformation and collapse of the residual soil into the bedrock cavities. A finite element analysis investigated the effects of bedrock cavity radius, thickness of soil overburden, and surface surcharge upon the deformational and stability characteristics of the residual soil. The results indicate that for small cavity radii, the thickness of the soil cover has little effect on the zone of yielded soil. For large cavity radii, a smaller zone of distressed soil occurs under thick soil cover than under thin soil cover. Dimensionless curves are presented to enable the prediction of the vertical extent of the zone of yielded soil for a range of site geometries. Although the thick soil deposits (100 feet or greater) typically found on the ridges result in high stresses adjacent to the cavity, the area of the distressed or yielded soil is small and unlikely to extend to the surface. In addition, the surface deformation or subsidence is expected to be minimal. Thus, the siting of waste facilities on the ridges where the overburden is maximum would tend to reduce the effects of deformation into the cavities. 29 refs., 37 figs., 7 tabs

1987-01-01

145

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

146

Dryland soil microbial communities display spatial biogeographic patterns associated with soil depth and soil parent material.  

Science.gov (United States)

Biological soil crusts (biocrusts) are common to drylands worldwide. We employed replicated, spatially nested sampling and 16S rRNA gene sequencing to describe the soil microbial communities in three soils derived from different parent material (sandstone, shale, and gypsum). For each soil type, two depths (biocrusts, 0-1 cm; below-crust soils, 2-5 cm) and two horizontal spatial scales (15 cm and 5 m) were sampled. In all three soils, Cyanobacteria and Proteobacteria demonstrated significantly higher relative abundance in the biocrusts, while Chloroflexi and Archaea were significantly enriched in the below-crust soils. Biomass and diversity of the communities in biocrusts or below-crust soils did not differ with soil type. However, biocrusts on gypsum soil harbored significantly larger populations of Actinobacteria and Proteobacteria and lower populations of Cyanobacteria. Numerically dominant operational taxonomic units (OTU; 97% sequence identity) in the biocrusts were conserved across the soil types, whereas two dominant OTUs in the below-crust sand and shale soils were not identified in the gypsum soil. The uniformity with which small-scale vertical community differences are maintained across larger horizontal spatial scales and soil types is a feature of dryland ecosystems that should be considered when designing management plans and determining the response of biocrusts to environmental disturbances. PMID:23621290

Steven, Blaire; Gallegos-Graves, La Verne; Belnap, Jayne; Kuske, Cheryl R

2013-05-20

147

Dryland soil microbial communities display spatial biogeographic patterns associated with soil depth and soil parent material.  

UK PubMed Central (United Kingdom)

Biological soil crusts (biocrusts) are common to drylands worldwide. We employed replicated, spatially nested sampling and 16S rRNA gene sequencing to describe the soil microbial communities in three soils derived from different parent material (sandstone, shale, and gypsum). For each soil type, two depths (biocrusts, 0-1 cm; below-crust soils, 2-5 cm) and two horizontal spatial scales (15 cm and 5 m) were sampled. In all three soils, Cyanobacteria and Proteobacteria demonstrated significantly higher relative abundance in the biocrusts, while Chloroflexi and Archaea were significantly enriched in the below-crust soils. Biomass and diversity of the communities in biocrusts or below-crust soils did not differ with soil type. However, biocrusts on gypsum soil harbored significantly larger populations of Actinobacteria and Proteobacteria and lower populations of Cyanobacteria. Numerically dominant operational taxonomic units (OTU; 97% sequence identity) in the biocrusts were conserved across the soil types, whereas two dominant OTUs in the below-crust sand and shale soils were not identified in the gypsum soil. The uniformity with which small-scale vertical community differences are maintained across larger horizontal spatial scales and soil types is a feature of dryland ecosystems that should be considered when designing management plans and determining the response of biocrusts to environmental disturbances.

Steven B; Gallegos-Graves LV; Belnap J; Kuske CR

2013-10-01

148

Study of Effective Soil Compaction Control of Granular Soils.  

Science.gov (United States)

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 ...

A. Evans A. Prochaska V. Drnevich

2007-01-01

149

Saline waters and soil quality  

Directory of Open Access Journals (Sweden)

Full Text Available 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 the soil quality. If on one hand the presence of salts can benefit the soils mainly improving soil structure, on the other high levels of salts produce negative effects on soils and crops.When sodium prevails problems of soil quality can rise such as structure degradation, low hydraulic conductivity, soil sealing. The processes of secondary soil salinization due to the use of saline waters for irrigation are particularly evident in our Country among others. In Italy, saline soils are mainly distributed in long strips of the coastal belt of the Tyrrhenian sea and Adriatic sea, in the coastal belt of Apulia, Basilicata and Sardinia and in wide areas of Sicily. It is not possible to suggest general actions to combat soil salinization because we must take into consideration that in the relationship soil-water two different quality concept interact: one linked to the soils, the other to the waters.

Carmelo Dazzi

2011-01-01

150

Saline waters and soil quality  

Directory of Open Access Journals (Sweden)

Full Text Available 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 the soil quality. If on one hand the presence of salts can benefit the soils mainly improving soil structure, on the other high levels of salts produce negative effects on soils and crops.When sodium prevails problems of soil quality can rise such as structure degradation, low hydraulic conductivity, soil sealing. The processes of secondary soil salinization due to the use of saline waters for irrigation are particularly evident in our Country among others. In Italy, saline soils are mainly distributed in long strips of the coastal belt of the Tyrrhenian sea and Adriatic sea, in the coastal belt of Apulia, Basilicata and Sardinia and in wide areas of Sicily. It is not possible to suggest general actions to combat soil salinization because we must take into consideration that in the relationship soil-water two different quality concept interact: one linked to the soils, the other to the waters.

Carmelo Dazzi

151

Saline waters and soil quality  

Directory of Open Access Journals (Sweden)

Full Text Available 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 the soil quality. If on one hand the presence of salts can benefit the soils mainly improving soil structure, on the other high levels of salts produce negative effects on soils and crops.When sodium prevails problems of soil quality can rise such as structure degradation, low hydraulic conductivity, soil sealing. The processes of secondary soil salinization due to the use of saline waters for irrigation are particularly evident in our Country among others. In Italy, saline soils are mainly distributed in long strips of the coastal belt of the Tyrrhenian sea and Adriatic sea, in the coastal belt of Apulia, Basilicata and Sardinia and in wide areas of Sicily. It is not possible to suggest general actions to combat soil salinization because we must take into consideration that in the relationship soil-water two different quality concept interact: one linked to the soils, the other to the waters.

Carmelo Dazzi

2006-01-01

152

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.; Onishchenko L. M.; Shvets T. V.

2013-01-01

153

APPARATUS FOR TREATING SOIL  

UK PubMed Central (United Kingdom)

Apparatus for treating the soil of a grass playing field (10) that includes a piping system containing perforated pipe lines (17) seated in a distribution bed (15) beneath the soil (11) of the playing field (10). A blower (30) having a discharge port (38) and a suction port (42) is selectively connected to the duct networks to either pump air upwardly or draw air downwardly through the soil profile. A separator (31) is connected in the air supply line (40) of the system for removing water from the air stream moving between the blower (30) and the duct network. The removed water is collected in a holding tank (60) for recycling, or disposed of in an environmentally safe manner.

BENSON William M.

154

Soil Litter: Unidentified Species  

Science.gov (United States)

In this two-minute sound segment, with the calls of a wood thrush in the background, a soil biologist discusses the probability that new species can be discovered in any handful of soil. He claims that when you pick up a handful of soil anywhere, whether it is in your backyard or in a forest, if you look at it closely enough, there will be organisms there that we have never seen before, especially microbial organisms. This site is an archive of a daily radio program called Pulse of the Planet, which provides its listeners with a portrait of Planet Earth, tracking the rhythms of nature, culture and science worldwide and blending interviews and extraordinary natural sound. The site also provides a written transcript of the broadcast.

2006-06-28

155

Soil surface fertilizer applicator  

UK PubMed Central (United Kingdom)

The application discloses a soil surface fertilizer applicator comprising a box body I, a strap 4 and a fertilizing tube 3. The soil surface fertilizer applicator is characterized in that a convenient flowing plate 2 is arranged inside the box body 1, and a switch 5 and a telescopic tube 6 are arranged in the middle of the fertilizing tube 3. By adopting the soil surface fertilizer applicator, when the fertilizer is applied, people do not need to bend the waist, and the fertilizer can be applied to the roots of the seedlings directly, so that the phenomenon of seedling burning can be prevented, the fertilizing efficiency and the fertilizing effect can be improved, and the labor intensity of the fertilizing can be reduced.

YANJUN CHENG

156

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

157

Dissipation of Soil Fumigants from Soil Following Repeated Applications.  

UK PubMed Central (United Kingdom)

BACKGROUND: Dissipation of pesticides in soil and occurrence of accelerated degradation following repeated applications is well known with many pesticides, but much less so with soil fumigants. The fate of various soil fumigants was studied in different agricultural soils following repeated applications of chloropicrin. RESULTS: Fumigant dissipation reflected by ?Concentration x Time (?CxT) and half-life values varied widely among the tested soils. Methyl iodide (MI) had the slowest dissipation rate compared with other fumigants in all tested soils. Elimination of biotic agents by soil sterilization prior to MI application did not affect MI concentration in Oxnard soil. Clay content and fumigant dose (?CxT values) of chloropicrin, 1,3-dichloropropene and MI were significantly correlated. No significant correlations were found between soil properties and ?CxT values following metam sodium and methyl bromide (MBr) application. CONCLUSION: The fate of tested soil fumigants is highly dependent on and specific to the fumigant, previous fumigant application and soil type. This study suggests that biotic factors are more essential in the dissipation of metam sodium and MBr than abiotic factors. By contrast, MI dissipation from the tested soils is affected more by abiotic factors than biotic activities.

Triky-Dotan S; Ajwa HA

2013-06-01

158

Fermilab Soil Activation Experience  

Energy Technology Data Exchange (ETDEWEB)

Soil borings were made at Fermilab locations of highest soil activation and samples analyzed to determine whether or not any leached radionuclides were moving toward the aquifer under the site. One boring extended underneath the primary target in the Neutrino Area, a target which has received most of the protons produced by the accelerator. The other recent boring was adjacent to the thinly shielded abort system which received protons which were improperly transported through the accelerator magnets or left in the accelerator after proton beam extraction. No evidence was found for movement of radionuclides toward the aquifer in concentrations approaching the community drinking water supply standards.

Baker, Samuel I.; /Fermilab

1984-01-01

159

Rock and soil mechanics  

CERN Document Server

Although theoretical in character, this book provides a useful source of information for those dealing with practical problems relating to rock and soil mechanics - a discipline which, in the view of the authors, attempts to apply the theory of continuum to the mechanical investigation of rock and soil media. The book is in two separate parts. The first part, embodying the first three chapters, is devoted to a description of the media of interest. Chapter 1 introduces the main argument and discusses the essence of the discipline and its links with other branches of science which are concern

Derski, W; Kisiel, I; Mróz, Z

2012-01-01

160

Soil Fertility Protocol  

Science.gov (United States)

The purpose of this resource is to measure the amounts of nitrogen, phosphorous and potassium in each horizon in a soil profile. Using a NPK test kit, students mix a dry, sieved soil sample into a solution and chemically extract the N, P, and K as nitrate, phosphate, and potassium. The N, P, and K amounts in the sample are determined by comparing the solution to a color chart. Students describe the N, P, K amounts as high, medium, low, or none. These measurements are conducted three times for each horizon.

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

2003-08-01

 
 
 
 
161

Soil monitoring instrumentation  

International Nuclear Information System (INIS)

[en] The Los Alamos Scientific Laboratory (LASL) has an extensive program for the development of nondestructive assay instrumentation for the quantitative analysis of transuranic (TRU) materials found in bulk solid wastes generated by Department of Energy facilities and by the commercial nuclear power industry. Included are wastes generated in decontamination and decommissioning of outdated nuclear facilities as well as wastes from old waste burial ground exhumation programs. The assay instrumentation is designed to have detection limits below 10 nCi/g wherever practicable. Because of the topic of this workshop, only the assay instrumentation applied specifically to soil monitoring will be discussed here. Four types of soil monitors are described

1979-12-05

162

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

163

Prediction of soil temperature distribution  

Energy Technology Data Exchange (ETDEWEB)

The quantitative relationship between insolation and the temperature of soil surface is discussed. A formula is established for the soil temperature as a function of depth for different amounts of incident solar radiation and temperature of ambient medium. 6 references.

Avezov, R.; Kasymov, B.Kh.; Niyazov, Sh.K.

1981-01-01

164

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; Florian St?tescu

2012-01-01

165

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

166

Relationships between soil physicochemical, microbiological properties, and nutrient release in buffer soils compared to field soils.  

UK PubMed Central (United Kingdom)

The retention of nutrients in narrow, vegetated riparian buffer strips (VBS) is uncertain and underlying processes are poorly understood. Evidence suggests that buffer soils are poor at retaining dissolved nutrients, especially phosphorus (P), necessitating management actions if P retention is not to be compromised. We sampled 19 buffer strips and adjacent arable field soils. Differences in nutrient retention between buffer and field soils were determined using a combined assay for release of dissolved P, N, and C forms and particulate P. We then explored these differences in relation to changes in soil bulk density (BD), moisture, organic matter by loss on ignition (OM), and altered microbial diversity using molecular fingerprinting (terminal restriction fragment length polymorphism [TRFLP]). Buffer soils had significantly greater soil OM (89% of sites), moisture content (95%), and water-soluble nutrient concentrations for dissolved organic C (80%), dissolved organic N (80%), dissolved organic P (55%), and soluble reactive P (70%). Buffer soils had consistently smaller bulk densities than field soils. Soil fine particle release was generally greater for field than buffer soils. Significantly smaller soil bulk density in buffer soils than in adjacent fields indicated increased porosity and infiltration in buffers. Bacterial, archaeal, and fungal communities showed altered diversity between the buffer and field soils, with significant relationships with soil BD, moisture, OM, and increased solubility of buffer nutrients. Current soil conditions in VBS appear to be leading to potentially enhanced nutrient leaching via increasing solubility of C, N, and P. Manipulating soil microbial conditions (by management of soil moisture, vegetation type, and cover) may provide options for increasing the buffer storage for key nutrients such as P without increasing leaching to adjacent streams.

Stutter MI; Richards S

2012-03-01

167

Relationships between soil physicochemical, microbiological properties, and nutrient release in buffer soils compared to field soils.  

Science.gov (United States)

The retention of nutrients in narrow, vegetated riparian buffer strips (VBS) is uncertain and underlying processes are poorly understood. Evidence suggests that buffer soils are poor at retaining dissolved nutrients, especially phosphorus (P), necessitating management actions if P retention is not to be compromised. We sampled 19 buffer strips and adjacent arable field soils. Differences in nutrient retention between buffer and field soils were determined using a combined assay for release of dissolved P, N, and C forms and particulate P. We then explored these differences in relation to changes in soil bulk density (BD), moisture, organic matter by loss on ignition (OM), and altered microbial diversity using molecular fingerprinting (terminal restriction fragment length polymorphism [TRFLP]). Buffer soils had significantly greater soil OM (89% of sites), moisture content (95%), and water-soluble nutrient concentrations for dissolved organic C (80%), dissolved organic N (80%), dissolved organic P (55%), and soluble reactive P (70%). Buffer soils had consistently smaller bulk densities than field soils. Soil fine particle release was generally greater for field than buffer soils. Significantly smaller soil bulk density in buffer soils than in adjacent fields indicated increased porosity and infiltration in buffers. Bacterial, archaeal, and fungal communities showed altered diversity between the buffer and field soils, with significant relationships with soil BD, moisture, OM, and increased solubility of buffer nutrients. Current soil conditions in VBS appear to be leading to potentially enhanced nutrient leaching via increasing solubility of C, N, and P. Manipulating soil microbial conditions (by management of soil moisture, vegetation type, and cover) may provide options for increasing the buffer storage for key nutrients such as P without increasing leaching to adjacent streams. PMID:22370402

Stutter, Marc I; Richards, Samia

168

Soil gas radon response to environmental and soil physics variables  

International Nuclear Information System (INIS)

[en] During the last three years a field study of soil gas radon activities conducted at Poamoho, Oahu, has shown that the primary environmental variables that control radon transport in shallow tropical soils are synoptic and diurnal barometric pressure changes and soil moisture levels. Barometric pressure changes drive advective transport and mixing of soil gas with atmospheric air; soil moisture appears to control soil porosity and permeability to enhance or inhibit advective and diffusive radon transport. An advective barrier test/control experiment has shown that advective exchange of soil gas and air may account for a substantial proportion of the radon loss from shallow soils but does not significantly affect radon activities at depths greater than 2.3 m. An irrigation test/control experiment also suggests that, at soil moisture levels approaching field capacity, saturation of soil macroporosity can halt all advective transport of radon and limit diffusive mobility to that occurring in the liquid phase. The results of the authors field study have been used to further refine and extend a numerical model, RN3D, that has been developed by Pacific Northwest Laboratories to simulate subsurface transport of radon. The field data have allowed them to accurately simulate the steady state soil gas radon profile at their field site and to track transient radon activities under the influence of barometric pressure changes and in response to changes in soil permeability that result from variations in soil moisture levels. Further work is continuing on the model to enable it to properly account for the relative effects of advective transport of soil gas through cracks and diffusive mobility in the bulk soils

1991-01-01

169

Silica Source in Soil Solutions.  

UK PubMed Central (United Kingdom)

Heat of solution of silica in soil saturation pastes was calculated from silica solubilities and agreed with values for solid silicic acid. The immediate source of silica in soil solutions apparently is solid silicic acid. The solution of silica from soils exhibited three stages of constant silica solubility.

Gifford RO; Frugoli DM

1964-07-01

170

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

171

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.

172

Soil carbon determination by thermogravimetrics  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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) emiss...

Robert Pallasser; Budiman Minasny; Alex B. McBratney

173

SOIL PHYSICS AND HYDROLOGY: CONDITIONERS  

Science.gov (United States)

Soil conditioners have been used since ancient times, even before the chemical and physical basis of conditioner effectiveness was accurately understood. Soil conditioners have included both organic and mineral materials as well as natural and synthetic materials. Examples of natural organic soil ...

174

Soil-Transmitted Helminth Infections  

Science.gov (United States)

Soil-transmitted helminth infections Fact sheet N°366 Updated June 2013 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 ...

175

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 ...

176

Unsaturated soils a fundamental interpretation of soil behaviour  

CERN Document Server

An understanding of the mechanical properties of unsaturated soils is crucial for geotechnical engineers worldwide, as well as to those concerned with the interaction of structures with the ground. This book deals principally with fine-grained clays and silts, or soils containing coarser sand and gravel particles but with a significant percentage of fines. The study of unsaturated soil is a practical subject, linking fundamental science to nature. Soils in general are inherently variable and their behaviour is not easy to analyse or predict, and unsaturated soils raise the complexity to a hi

Murray, E J

2010-01-01

177

Soil warming alters microbial substrate use in alpine soils.  

UK PubMed Central (United Kingdom)

Will warming lead to an increased use of older soil organic carbon (SOC) by microbial communities, thereby inducing C losses from C-rich alpine soils? We studied soil microbial community composition, activity and substrate use after three and four years of soil warming (+4°C, 2007-2010) at the alpine treeline in Switzerland. The warming experiment was nested in a free air CO2 enrichment experiment using depleted (13) CO2 (?(13) C = -30‰, 2001-2009). We traced this depleted (13) C label in phospholipid fatty acids (PLFA) of the organic layer (0-5 cm soil depth) and in C mineralized from root-free soils to distinguish substrate ages used by soil microorganisms: fixed before 2001 ("old"), from 2001 to 2009 ("new") or in 2010 ("recent"). Warming induced a sustained stimulation of soil respiration (+38%) without decline in mineralizable SOC. PLFA concentrations did not reveal changes in microbial community composition due to soil warming, but soil microbial metabolic activity was stimulated (+66%). Warming decreased the amount of new and recent C in the fungal biomarker 18:2?6,9 and the amount of new C mineralized from root-free soils, implying a shift in microbial substrate use towards a greater use of old SOC. This shift in substrate use could indicate an imbalance between C inputs and outputs, which could eventually decrease SOC storage in this alpine ecosystem. This article is protected by copyright. All rights reserved.

Streit K; Hagedorn F; Hiltbrunner D; Portmann M; Saurer M; Buchmann N; Wild B; Richter A; Wipf S; Siegwolf RT

2013-09-01

178

Soil Stabilization Study.  

Science.gov (United States)

This report concerns a laboratory study of the stabilization of soils from the Red River Valley and South-western North Dakota. Stabilizing treatments were Portland cement, hydrated high-calcium and dolomitic lime, high calcium lime and flyash, high calci...

O. E. Manz

1969-01-01

179

Soil and vegetation  

International Nuclear Information System (INIS)

Surface soil and vegetation samples are collected annually from a number of locations for the purpose of measuring the radionuclide concentrations from worldwide fallout, natural causes, and any cumulative buildup of radionuclides from Hanford operations. Radionuclide concentrations in samples taken during 1980 were similar to previous years. No obvious geographical radionuclide distribution pattern was observed in the 1980 samples

1981-01-01

180

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...

?uvardi? Maja S.

 
 
 
 
181

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

182

Soil washing results for mixed waste pond soils at Hanford  

International Nuclear Information System (INIS)

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

1991-01-01

183

Acid Rain Experiments: Soil Buffering  

Science.gov (United States)

This experiment will help students understand that soil sometimes contains substances, like limestone, that buffer acids or bases, and that some salts in soil may also act as buffers. They will collect soil samples from their lawn, garden, or school and look for buffering effects by observing the pH change of an acid mixture poured through the samples. If the water collected from the sample is less acidic than the original mixture, then the soil is buffering some of the acid. If it does not change, then the soil may not be capable of buffering acids.

184

Soil stabilization materials and methods  

Energy Technology Data Exchange (ETDEWEB)

For soil stabilization, a liquid applied to the surface of the soil rapidly polymerizes to form an elastomeric resin which bonds the soil particles together to form a tough composite structure within a time span of a few seconds to an hour, depending upon the composition of the soil stabilizer. The stabilizing materials are mixtures of dimer diisocyanate and dimer diamine, which react rapidly, and mixtures of dimer diisocyanate and a derivative of dimer diamine wherein the amine groups have been reacted with a ketone to form ketimine groups. The latter mixture, which reacts more slowly, may be premixed before application to soil surface. 5 claims.

Reed, R. Jr.; Moore, K.L.; Meyers, G.W.

1981-07-07

185

Geotechnical engineering in residual soils  

CERN Multimedia

Wiley has long held a pre-eminent position as a publisher of books on geotechnical engineering, with a particular strength in soil behavior and soil mechanics, at both the academic and professional level. This reference will be the first book focused entirely on the unique engineering properties of residual soil.  Given the predominance of residual soils in the under-developed parts of the United States and the Southern Hemisphere, and the increasing rate of new construction in these regions, the understanding of residual soils is expected to increase in importance in the coming years.  This b

Wesley, Laurence D

2010-01-01

186

Soil health in agricultural systems.  

Science.gov (United States)

Soil health is presented as an integrative property that reflects the capacity of soil to respond to agricultural intervention, so that it continues to support both the agricultural production and the provision of other ecosystem services. The major challenge within sustainable soil management is to conserve ecosystem service delivery while optimizing agricultural yields. It is proposed that soil health is dependent on the maintenance of four major functions: carbon transformations; nutrient cycles; soil structure maintenance; and the regulation of pests and diseases. Each of these functions is manifested as an aggregate of a variety of biological processes provided by a diversity of interacting soil organisms under the influence of the abiotic soil environment. Analysis of current models of the soil community under the impact of agricultural interventions (particularly those entailing substitution of biological processes with fossil fuel-derived energy or inputs) confirms the highly integrative pattern of interactions within each of these functions and leads to the conclusion that measurement of individual groups of organisms, processes or soil properties does not suffice to indicate the state of the soil health. A further conclusion is that quantifying the flow of energy and carbon between functions is an essential but non-trivial task for the assessment and management of soil health. PMID:17785275

Kibblewhite, M G; Ritz, K; Swift, M J

2008-02-27

187

Soil health in agricultural systems.  

UK PubMed Central (United Kingdom)

Soil health is presented as an integrative property that reflects the capacity of soil to respond to agricultural intervention, so that it continues to support both the agricultural production and the provision of other ecosystem services. The major challenge within sustainable soil management is to conserve ecosystem service delivery while optimizing agricultural yields. It is proposed that soil health is dependent on the maintenance of four major functions: carbon transformations; nutrient cycles; soil structure maintenance; and the regulation of pests and diseases. Each of these functions is manifested as an aggregate of a variety of biological processes provided by a diversity of interacting soil organisms under the influence of the abiotic soil environment. Analysis of current models of the soil community under the impact of agricultural interventions (particularly those entailing substitution of biological processes with fossil fuel-derived energy or inputs) confirms the highly integrative pattern of interactions within each of these functions and leads to the conclusion that measurement of individual groups of organisms, processes or soil properties does not suffice to indicate the state of the soil health. A further conclusion is that quantifying the flow of energy and carbon between functions is an essential but non-trivial task for the assessment and management of soil health.

Kibblewhite MG; Ritz K; Swift MJ

2008-02-01

188

Dynamical soil-structure interactions: influence of soil behaviour nonlinearities  

International Nuclear Information System (INIS)

[en] The interaction of the soil with the structure has been largely explored the assumption of material and geometrical linearity of the soil. Nevertheless, for moderate or strong seismic events, the maximum shear strain can easily reach the elastic limit of the soil behavior. Considering soil-structure interaction, the nonlinear effects may change the soil stiffness at the base of the structure and therefore energy dissipation into the soil. Consequently, ignoring the nonlinear characteristics of the dynamic soil-structure interaction (DSSI) this phenomenon could lead to erroneous predictions of structural response. The goal of this work is to implement a fully nonlinear constitutive model for soils into a numerical code in order to investigate the effect of soil nonlinearity on dynamic soil structure interaction. Moreover, different issues are taken into account such as the effect of confining stress on the shear modulus of the soil, initial static condition, contact elements in the soil-structure interface, etc. During this work, a simple absorbing layer method based on a Rayleigh/Caughey damping formulation, which is often already available in existing Finite Element softwares, is also presented. The stability conditions of the wave propagation problems are studied and it is shown that the linear and nonlinear behavior are very different when dealing with numerical dispersion. It is shown that the 10 points per wavelength rule, recommended in the literature for the elastic media is not sufficient for the nonlinear case. The implemented model is first numerically verified by comparing the results with other known numerical codes. Afterward, a parametric study is carried out for different types of structures and various soil profiles to characterize nonlinear effects. Different features of the DSSI are compared to the linear case: modification of the amplitude and frequency content of the waves propagated into the soil, fundamental frequency, energy dissipation in the soil and the response of the soil-structure system. Through these parametric studies we show that depending on the soil properties, frequency content of the soil response could change significantly due to the soil nonlinearity. The peaks of the transfer function between free field and outcropping responses shift to lower frequencies and amplification happens at this frequency range. Amplification reduction for the high frequencies and even de-amplification may happen for high level input motions. These changes influence the structural response. We show that depending on the combination of the fundamental frequency of the structure and the the natural frequency of the soil, the effect of soil-structure interaction could be significant or negligible. However, the effect of structure weight and rocking of the superstructure could change the results. Finally, the basin of Nice is used as an example of wave propagation on a heterogeneous nonlinear media and dynamic soil-structure interaction. The basin response is strongly dependent on the combination of soil nonlinearity, topographic effects and impedance contrast between soil layers. For the selected structures and soil profiles of this work, the performed numerical simulations show that the shift of the fundamental frequency is not a good index to discriminate linear from nonlinear soil behavior. (author)

2011-01-01

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 3.47tSOCha(-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 6.8Pg 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

2012-09-05

191

Soil salinity decreases global soil organic carbon stocks.  

UK PubMed Central (United Kingdom)

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 3.47tSOCha(-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 6.8Pg 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.

Setia R; Gottschalk P; Smith P; Marschner P; Baldock J; Setia D; Smith J

2013-11-01

192

Modelling soil anaerobiosis from water retention characteristics and soil respiration  

UK PubMed Central (United Kingdom)

Oxygen is a prerequisite for some and an inhibitor to other microbial functions in soils, hence the temporal and spatial distribution of oxygen within the soil matrix is crucial in soil biogeochemistry and soil biology. Various attempts have been made to model the anaerobic fraction of the soil volume as a function of structure, moisture content and oxygen consumption. Aggregate models are attractive but difficult to parameterize and not applicable to non-aggregated soils. Pore models are preferable for pragmatic reasons, but the existing versions appear to overestimate the anaerobic volume at intermediate soil moisture contents. A modified pore model is proposed, in which anaerobiosis is calculated from a range of air filled pore size classes, based on the soil water retention curve and the soil moisture content. In comparison with previous pore models which are based on the estimation of an average size of the air filled pores, the pore class model presented here appears to give more adequate estimates of anaerobic volumes, especially at intermediate moisture contents. The pore model is attractive for process modelling of anaerobic functions such as denitrification, since it can easily be parameterized by the water retention characteristics of a soil.

Schurgers G; Dorsch P; Bakken L; Leffelaar P; Haugen LE

2006-09-01

193

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

International Nuclear Information System (INIS)

[en] 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)

2004-01-01

194

Soil column leaching of pesticides.  

UK PubMed Central (United Kingdom)

In this review, I address the practical and theoretical aspects of pesticide soil mobility.I also address the methods used to measure mobility, and the factors that influence it, and I summarize the data that have been published on the column leaching of pesticides.Pesticides that enter the unsaturated soil profile are transported downwards by the water flux, and are adsorbed, desorbed, and/or degraded as they pass through the soil. The rate of passage of a pesticide through the soil depends on the properties of the pesticide, the properties of the soil and the prevailing environmental conditions.Because large amounts of many different pesticides are used around the world, they and their degradates may sometimes contaminate groundwater at unacceptable levels.It is for this reason that assessing the transport behavior and soil mobility of pesticides before they are sold into commerce is important and is one indispensable element that regulators use to assess probable pesticide safety. Both elementary soil column leaching and sophisticated outdoor lysimeter studies are performed to measure the leaching potential for pesticides; the latter approach more reliably reflects probable field behavior, but the former is useful to initially profile a pesticide for soil mobility potential.Soil is physically heterogeneous. The structure of soil varies both vertically and laterally, and this variability affects the complex flow of water through the soil profile, making it difficult to predict with accuracy. In addition, macropores exist in soils and further add to the complexity of how water flow occurs. The degree to which soil is tilled, the density of vegetation on the surface, and the type and amounts of organic soil amendments that are added to soil further affect the movement rate of water through soil, the character of soil adsorption sites and the microbial populations that exist in the soil. Parameters that most influence the rate of pesticide mobility in soil are persistence (DT50) of the pesticide, and its sorption/desorption(Koc) characteristics. These parameters may vary for the same pesticide from geographic site-to-site and with soil depth. The interactions that normally occur between pesticides and dissolved organic matter (DOM) or WDC are yet other factors that may complicate pesticide leaching behavior.The soil mobility of pesticides is normally tested both in the laboratory and in the field. Lab studies are initially performed to give researchers a preliminary appraisal of the relative mobility of a pesticide. Later, field lysimeter studies can be performed to provide more natural leaching conditions that emulate the actual field use pattern. Lysimeter studies give the most reliable information on the leaching behavior of a pesticide under field conditions, but these studies are time-consuming and expensive and cannot be performed everywhere. It is for this reason that the laboratory soil column leaching approach is commonly utilized to profile the mobility of a pesticide,and appraise how it behaves in different soils, and relative to other pesticides.Because the soil structure is chemically and physically heterogenous, different pesticide tests may produce variable DT50 and Koc values; therefore, initial pesticide mobility testing is undertaken in homogeneously packed columns that contain two or more soils and are eluted at constant flow rates. Such studies are done in duplicate and utilize a conservative tracer element. By fitting an appropriate mathematical model to the breakthrough curve of the conservative tracer selected,researchers determine key mobility parameters, such as pore water velocity, the column-specific dispersion coefficient, and the contribution of non equilibrium transport processes. Such parameters form the basis for estimating the probable transport and degradation rates that will be characteristic of the tested pesticide. Researchers also examine how a pesticide interacts with soil DOM and WDC, and what contribution from facilitated transport to mobility is made as a result of the effects of

Katagi T

2013-01-01

195

Soil column leaching of pesticides.  

Science.gov (United States)

In this review, I address the practical and theoretical aspects of pesticide soil mobility.I also address the methods used to measure mobility, and the factors that influence it, and I summarize the data that have been published on the column leaching of pesticides.Pesticides that enter the unsaturated soil profile are transported downwards by the water flux, and are adsorbed, desorbed, and/or degraded as they pass through the soil. The rate of passage of a pesticide through the soil depends on the properties of the pesticide, the properties of the soil and the prevailing environmental conditions.Because large amounts of many different pesticides are used around the world, they and their degradates may sometimes contaminate groundwater at unacceptable levels.It is for this reason that assessing the transport behavior and soil mobility of pesticides before they are sold into commerce is important and is one indispensable element that regulators use to assess probable pesticide safety. Both elementary soil column leaching and sophisticated outdoor lysimeter studies are performed to measure the leaching potential for pesticides; the latter approach more reliably reflects probable field behavior, but the former is useful to initially profile a pesticide for soil mobility potential.Soil is physically heterogeneous. The structure of soil varies both vertically and laterally, and this variability affects the complex flow of water through the soil profile, making it difficult to predict with accuracy. In addition, macropores exist in soils and further add to the complexity of how water flow occurs. The degree to which soil is tilled, the density of vegetation on the surface, and the type and amounts of organic soil amendments that are added to soil further affect the movement rate of water through soil, the character of soil adsorption sites and the microbial populations that exist in the soil. Parameters that most influence the rate of pesticide mobility in soil are persistence (DT50) of the pesticide, and its sorption/desorption(Koc) characteristics. These parameters may vary for the same pesticide from geographic site-to-site and with soil depth. The interactions that normally occur between pesticides and dissolved organic matter (DOM) or WDC are yet other factors that may complicate pesticide leaching behavior.The soil mobility of pesticides is normally tested both in the laboratory and in the field. Lab studies are initially performed to give researchers a preliminary appraisal of the relative mobility of a pesticide. Later, field lysimeter studies can be performed to provide more natural leaching conditions that emulate the actual field use pattern. Lysimeter studies give the most reliable information on the leaching behavior of a pesticide under field conditions, but these studies are time-consuming and expensive and cannot be performed everywhere. It is for this reason that the laboratory soil column leaching approach is commonly utilized to profile the mobility of a pesticide,and appraise how it behaves in different soils, and relative to other pesticides.Because the soil structure is chemically and physically heterogenous, different pesticide tests may produce variable DT50 and Koc values; therefore, initial pesticide mobility testing is undertaken in homogeneously packed columns that contain two or more soils and are eluted at constant flow rates. Such studies are done in duplicate and utilize a conservative tracer element. By fitting an appropriate mathematical model to the breakthrough curve of the conservative tracer selected,researchers determine key mobility parameters, such as pore water velocity, the column-specific dispersion coefficient, and the contribution of non equilibrium transport processes. Such parameters form the basis for estimating the probable transport and degradation rates that will be characteristic of the tested pesticide. Researchers also examine how a pesticide interacts with soil DOM and WDC, and what contribution from facilitated transport to mobility is made as a result of the effects of

Katagi, Toshiyuki

2013-01-01

196

Pneumatic soil removal tool  

Energy Technology Data Exchange (ETDEWEB)

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

Pneumatic soil removal tool  

International Nuclear Information System (INIS)

[en] 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. 3 figs

1991-01-23

198

The soils of Mars  

Science.gov (United States)

A mineralogical model for the Mars fine soil that includes as major components smectite clays absorbed and coated with amorphous iron oxyhydroxides and perhaps mixed with small amounts of better-crystalized iron oxides as separate phases is proposed. Also present as accessory minerals are sulfate minerals such as kieserite (MgSO4.H2O) and/or anhydrite (CaSO4), rutile (TiO2), and maghemite (Fe2O3) or magnetite (Fe3O4), the last two as magnetic components. Carbonates may be present at low concentrations only (less than 1 to 2 pct). However, a prime question to be addressed by a Mars Sample Return Mission shall be related to the mineralogical composition of the soil, and its spatial variability.

Banin, A.

199

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.

1991-01-01

200

ree soil improvement agents  

UK PubMed Central (United Kingdom)

A powdered anti-dust soil conditioner or conditioner/fertiliser comprises a) at least one mineral support which is a calcium carbonate, double carbonate of calcium and magnesium or dolomite, calcium or magnesium chalks, magnesium oxide, natural phosphate, potash, and their mixtures, optionally with a powdered or granular nitrogen source such as urea, ammonium sulphate, monoammonium phosphate, diammonium phosphate, or super triple phosphate, b) 0.5-5% by weight, relative to the weight of a), of an anti-dust agent which is compatible with soil conditioners, such as one or more vegetable and/or mineral oils, vegetable oil by-products, amines, molasses, gums, or binders, and c) optionally water.

GUERRINI ETIENNE

 
 
 
 
201

A soil resistance model for pipelines on sandy soils  

Energy Technology Data Exchange (ETDEWEB)

This paper presents a pipe-soil interaction model for sand soils capable of predicting the development of pipe penetration into the soil and the associates soil resistance that may be mobilized against horizontal pipe motions. The model is based on dimensional analysis and development of appropriate empirical equations which are fitted to large-scale laboratory data from several sources. The development of penetration is described by considering the work done by the pipe on the soil. For a given penetration, the force-displacement curve is described. The model has been used to predict time histories of penetration and horizontal pipe displacement from large-scale laboratory tests where pipe sections were subjected to forces representative of those from irregular waves and currents. A good reproduction of the time development of both penetration and displacement is given over the whole range of relevant hydrodynamic and soil parameters.

Verley, R.L.P. (Statoil, Trondheim (Norway)); Sotberg, T. (Sintef, Trondheim (Norway))

1994-08-01

202

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

203

SOIL PREPARATION UNIT  

UK PubMed Central (United Kingdom)

Soil tillage entity comprising at least a first disc entity (6) with a first disc (12) and at least a second disc entity (10) with a second disc (14) for soil tillage, wherein the disc entities (6, 10) are arranged at an agricultural machine orientated in different directions in such a way, that the horizontal components of force (F1, F2; S1, S2) orthogonally against the direction of travel originating from the tilling of the discs in the soil have the opposite direction. According to the invention, the first disc entity (6) and the second disc entity (10) are associated with each other and are intended to be arranged at a frame (16) by means of a suspending device (25) in such a way that the horizontal components of force orthogonally against the direction of travel essentially eliminate each other. Alternatively, the first disc entity (6) and the second disc entity (10) are associated with each other and are intended to be arranged relative to a frame (16) by means of a suspending device (25) in such a way that the horizontal components of force for the resp. disc entity (6, 10) essentially do not cause a turning moment around a vertical axis, the position of which is predetermined.

GILSTRING Gert; INGEMARSSON Marcus

204

Solos urbanos/ Urban soils  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese A forte pressão provocada pela expansão urbana desordenada sobre os recursos naturais, principalmente os solos, tem provocado danos, muitas vezes de difícil reparo. A grande concentração populacional em centros urbanos cada vez maiores tem dirigido a atenção de diferentes profissionais para o recurso solo, no sentido de entender sua dinâmica para minimizar sua degradação. No entanto, a falta de conhecimento sobre as propriedades, bem como sobre a aptidão dos so (more) los sob uso urbano tem provocado o seu mau uso, resultando em processos como compactação, erosão, deslizamentos e inundações, assim como poluição com substâncias orgânicas, inorgânicas e patógenos, aumentando os custos do desenvolvimento afetando toda a sociedade. Neste sentido, este texto discute como o conhecimento pedológico pode diminuir os efeitos negativos provocados pelo processo de urbanização. Abstract in english The strong pressure caused by the disordered urban expansion over the natural resources, mainly the soils, has caused damages, many times difficult to repair. The great population concentration in urban centers getting larger and larger has been driving the attention of different professionals to soil resource, in the sense of understanding its dynamics to minimize its degradation. The lack of knowledge related to the soils properties and capability promote their inapprop (more) riate use, resultig in degrading processes as compaction, erosion, sliding, floods, and organic, inorganic and patogenic pollution, increasing the cost of development and affecting the whole society. This text discusses how pedologic knowledge can reduce the negative effects caused by the urbanization process.

Pedron, Fabrício de Araújo; Dalmolin, Ricardo Simão Diniz; Azevedo, Antônio Carlos de; Kaminski, João

2004-10-01

205

Soil and terrestial indicators  

International Nuclear Information System (INIS)

[en] Long-lived radionuclides 90Sr, 137Cs and 239,240Pu in soil are analysed in the vicinity of nuclear power stations every four years. Both vertical disribution and the total amount of radionuclides per unit of area are determined from the samples. The results of surveys carried out at Loviisa in 1983 and at Olkiluoto in 1984 are presented here. The total deposition determined by soil samples had decreased slightly since the previous soil studies and was, on average, 630 Bq m-2 of 90Sr, 1800 Bq m-2 137Cs and 30 Bq m-2 239,240Pu. To follow up short-lived radionuclides in deposition, an indicator organism, hair moss, is analysed four times a year in the vicinity of nuclear power stations. Hair moss principally reflects the fall-out from nuclear weapon tests. Small amounts of 60Co released from power stations was also detectable. Both an indicator and a step in the food chain leading to man, pasture grass was analysed in the vicinity of nuclear power stations twice during the growing season. The concentrations of 137Cs were very low, and no 131I was detected. The results for hair moss and pasture grass at Loviisa from 1980-1985 and from 1981-1985 at Olkiluoto are given

1987-01-01

206

Contaminated soil stabilization demonstration  

Energy Technology Data Exchange (ETDEWEB)

Long-term herbicide control along with a shotcrete cover was constructed at the Hanford Site in May 1991. The cover system allows for maintenance-free containment of contaminants by preventing wind and water transport of contaminants from the soil surface, preventing plant uptake of contaminants, and minimizing water infiltration through the soil column. The cover is composed of two parts: a commercial nonwoven geotextile material impregnated with trifluralin, and a >5-centimeter top cover of shotcrete containing polyethylene fibers. The herbicide-impregnated geotextile functions to prevent plant root growth into contaminated soil if any holes or cracks develop in the shotcrete layer. The herbicide component, trifluralin, is mixed into polymer nodules that degrade slowly over many years, thus releasing trifluralin slowly over time. The shotcrete topcover was sprayed using a sludge pump and air compressor to form a hard, impenetrable surface that prevents wind erosion and reduces water infiltration through the contaminated materials underneath. The benefits of the cover system are expected to last 20 to 30 years. 2 refs., 4 figs.

Kemp, C.J.; Sackschewsky, M.R.; Sampson, A.E.; Phillips, S.J.

1991-10-01

207

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

1999-01-01

208

Soil Properties Database of Spanish Soils Volume I.-Galicia  

International Nuclear Information System (INIS)

[en] 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

209

Soil Properties Database of Spanish Soils Volume III.- Extremadura  

International Nuclear Information System (INIS)

[en] 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

210

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

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 Aragon. (Author) 47 refs.

1999-01-01

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

Investigation of Wetland Soil Properties affecting Optimum Soil Cultivation  

Directory of Open Access Journals (Sweden)

Full Text Available An investigation was carried out on wetland (fadama) soil properties affecting optimum soil cultivation. A cone penetrometerand a shear vane apparatus (19 mm) were used to determine the cone index and the torque that cause the soil to shearat different moisture contents. The study shows that the cone index and shear vane of fadama soils increased with depth anddecreased with increase in moisture content. High moisture content reduced the soil cohesion. The internal frictional angleof the soil was 37.90. The following values were obtained for soil cohesion 112 kN/m2, 62 kN/m2, 38 kN/m2, 30 kN/m2, and12 kN/m2 at moisture contents of 0%, 5%, 10%, 15% and 20% respectively. Moisture content between 10% -15% (dry basis)appeared ideal for cultivation of the soil. For this soil the critical moisture content was found to be 23.72%. Moisture contentbeyond the critical level needs to be drained before cultivation is carried out.

K.A. Adeniran; O.O. Babatunde

2010-01-01

213

Forest soil disturbance intervals inferred from soil charcoal radiocarbon dates  

International Nuclear Information System (INIS)

Forest soil disturbance intervals are usually too long to measure using plot-based studies, and thus they are poorly understood. The mean soil disturbance interval (MSDI) in an old-growth forest on the west coast of Vancouver Island was estimated from radiocarbon dates of charcoal from organic and mineral soil horizons. Two assumptions are required to estimate the MSDI: charcoal from forest fires is deposited within the organic horizon and eventually mixed into deeper mineral horizons by soil disturbances, and the probability of soil disturbance is spatially homogeneous and affected only by the time since the last fire or the last soil disturbance. The MSDI is then estimated by the rate at which the proportion of undisturbed sample sites (determined by the proportion of sites with charcoal from the most recent fire in the organic horizon) decreases with increasing time since the last fire. Soil charcoal evidence of time since fire was determined at 83 sites using 141 radiocarbon dates. The estimated MSDI was greater on slopes (ca. 2010 years) than on terraces (ca. 920 years). The long periods between soil disturbances, especially on slopes, are consistent with other evidence from the study area that suggests infrequent tree uprooting is the predominant mode of soil disturbance. (author)

2003-01-01

214

A soil quality index for reclaimed mine soils.  

UK PubMed Central (United Kingdom)

The quality of soils found in mines is low if they do not receive any reclamation treatment. To our knowledge, there are no still equations to evaluate the quality of metal contaminated mine soils after the application of the reclamation treatments mainly in use today (planting vegetation and amending with wastes). Therefore, the purposes of the present study was (i) to propose a method for developing soil quality indexes (SQI), (ii) to develop the SQI for two types of mine soils (settling pond and mine tailing) reclaimed by planting trees and/or amending with wastes and (iii) 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 a soil quality index with a factor analysis and the totalling 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 them was amending with wastes (sewage sludges and paper mill residues). We recommend the periodic addition of sewage sludges and paper mill residues to degraded sites as they increase the quality of soils but the effect decrease over time. Environ Toxicol Chem © 2013 SETAC.

Asensio V; Guala SD; Vega FA; Covelo EF

2013-06-01

215

Incineration of PCB-contaminated soils: Effect on soil properties  

Energy Technology Data Exchange (ETDEWEB)

An experimental program was conducted to determine the effect of fluidized bed combustion on the properties and characteristics of a soil lightly contaminated with PCBs. The following properties of a soil sample and its leachate were characterized before and after incineration: pH, particle size distribution, and contaminant content. Three runs were carried out on a pilot scale fluidized bed at identical conditions, with three different soil samples: set point temperature of 870 {+-} 40 C and minimal residence time of 30 min. The main conclusions can be summarized as follows: under the operating conditions of the test, PCBs present in soil are eliminated to below the detection level; the runs showed good reproducibility; soil pH increases from 8.6 {+-} 0.1 to 10.7 {+-} 0.2 because of the natural limestone (CaCO{sub 3}), which calcines and then hydrolyzes to basic calcium hydroxide (Ca(OH){sub 2}); the incineration seems to lead to soil agglomeration; soil heavy metal content is decreased significantly after incineration; soil leachate heavy metal content is not significantly affected by incineration, except for chromium (from 0.02 to 0.06 mg/L) and zinc (from 0.1 to 0.25 mg/L); treated soil leachate content for organics and organochlorines is below the detection level.

Chaouki, J.; Guy, C.; Gonzalez, A. [Ecole Polytechnique, Montreal, Quebec (Canada). Chemical Engineering Dept.; Mourot, P. [SNC Lavalin Inc., Montreal, Quebec (Canada); Masciotra, P. [CINTEC Environnement Inc., Lasalle, Quebec (Canada)

1995-12-31

216

A soil quality index for reclaimed mine soils.  

UK PubMed Central (United Kingdom)

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.

Asensio V; Guala SD; Vega FA; Covelo EF

2013-10-01

217

Unsaturated soil mechanics in geotechnical practice  

CERN Document Server

There are other books on unsaturated soil mechanics, but this book is different. Unsaturated soil mechanics is only one aspect of a continuous range of soil mechanics studies that extends from the rheology of high water content soil slurries to the mechanics of soft soils, to stiff saturated soils, to unsaturated soils, and, at the far end of the range, to dry soils. In reality, the water content of all soils, that are not permanently submerged, varies seasonally. In most climatic zones, rainfall varies during the year and the depth of the water table varies sympathetically. In applying unsatu

Blight, Geoffrey E

2013-01-01

218

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

219

Horizontal Infiltration Into Wet Soil  

UK PubMed Central (United Kingdom)

We obtain the long-time asymptotic similarity solution for the wetting front for water absorptionfrom a constant source into a homogeneous layer of soil with a pre-existing moisture distribution.The presence of the initial water distribution in the soil introduces a time-shift that advances theposition of the wetting front. The time-shift can be explicitly calculated for any form ofdiffusivity. A dynamic time-shift is derived to yield a very efficient means for estimating thewater content distribution and front position for all times in Brooks-Corey type soil models.2IntroductionWe study the problem of estimating the motionof wetting fronts for water absorption into unsaturatedlayers of soil that already have some distributionof moisture content. Let ` be a normalized volumetricwater content, with ` = 1 corresponding tothe maximum water content, occurring at a constantsource at the edge of the soil layer, x = 0, and ` = 0describing dry soil. Richards' equation [Richa...

T. P. Witelski

220

Soil carbon, soil nitrate, and soil emissions of nitrous oxide during cultivation of energy crops  

UK PubMed Central (United Kingdom)

Carbon (C) sequestration and soil emissions of nitrous oxide (N?O) affect the carbon dioxide (CO?) advantage of energy crops. A long-term study has been performed to evaluate the environmental effects of energy crop cultivation on the loamy sand soil of the drier northeast region of Germany. The experimental field, established in 1994, consisted of columns (0.25 ha each) cultivated with short rotation coppice (SRC: Salix and Populus) and columns cultivated with annual crops. The columns were subdivided into four blocks, with each receiving different fertilization treatments. The soil C content was measured annually from 1994 until 1997, and then in 2006. Soil N?O levels were measured several times per week from 1999 to 2007. Water-filled pore space (WFPS) and soil nitrate measurements have been performed weekly since 2003. Increased C stocks were found in SRC columns, and C loss was observed in blocks with annual crops. The soil from fertilized blocks had higher levels of C than the soil from non-fertilized blocks. SRC cropping systems on dry, loamy sand soils are advantageous relative to annual cropping systems because of higher C sequestration, lower fertilized-induced N?O emissions, and reduced background N?O emissions in these soils. SRC cropping systems on dry, loamy sand soils have a CO? advantage (approximately 4 Mg CO? ha?¹ year?¹) relative to annual cropping systems.

Hellebrand HansJ; Strähle Martin; Scholz Volkhard; Kern Jürgen

2010-06-01

 
 
 
 
221

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

222

In-situ vitrification of soil  

Energy Technology Data Exchange (ETDEWEB)

A method of vitrifying soil at or below a soil surface location. Two or more conductive electrodes are inserted into the soil for heating of the soil mass between them to a temperature above its melting temperature. Materials in the soil, such as buried waste, can thereby be effectively immobilized.

Brouns, Richard A. (Kennewick, WA); Buelt, James L. (Richland, WA); Bonner, William F. (Richland, WA)

1983-01-01

223

Aflatoxin decomposition in various soils  

Energy Technology Data Exchange (ETDEWEB)

The persistence of aflatoxin in the soil environment could potentially result in a number of adverse environmental consequences. To determine the persistence of aflatoxin in soil, /sup 14/C-labeled aflatoxin B1, was added to silt loam, sandy loam, and silty clay loam soils and the subsequent release of /sup 14/CO/sub 2/ was determined. After 120 days of incubation, 8.1% of the original aflatoxin added to the silt loam soil was released as CO/sub 2/. Aflatoxin decomposition in the sandy loam soil proceeded more quickly than the other two soils for the first 20 days of incubation. After this time, the decomposition rate declined and by the end of the study, 4.9% of the aflatoxin was released as CO/sub 2/. Aflatoxin decomposition proceeded most slowly in the silty clay loam soil. Only 1.4% of aflatoxin added to the soil was released as CO/sub 2/ after 120 days incubation. To determine whether aflatoxin was bound to the silty clay loam soil, aflatoxin B1 was added to this soil and incubated for 20 days. The soil was periodically extracted and the aflatoxin species present were determined using thin layer chromatographic (TLC) procedures. After one day of incubation, the degradation products, aflatoxins B2 and G2, were observed. It was also found that much of the aflatoxin extracted from the soil was not mobile with the TLC solvent system used. This indicated that a conjugate may have formed and thus may be responsible for the lack of aflatoxin decomposition.

Angle, J.S.

1986-08-01

224

Fate of chromium in soil  

Energy Technology Data Exchange (ETDEWEB)

The chromium cycle in soil was studied with speciation of chromium. The aim was to look for the possibilities the mobilization of chromium(III) and to measure the rate of chromate reduction in nature and pot and field experiments in Hungarian soils. The authors developed a sensitive and simple method for chromium speciation with a microcolumn connected an inductively coupled plasma atomic emission spectrometer. Detection limits are convenient to measure chromium forms in a 0.01 M CaCl{sub 2} extract of a contaminated soil, but it is not enough to measure that of the uncontaminated soils. CR(VI) as chromate anion is not adsorbed on pH dependent temporary charges of clays but in strongly acidic soil. Therefore CR(VI) can be leached out easily from the top layer of soil and can be transported into the ground water. Chromate ion can be reduced to CR(III) by organic matter of soil in acidic medium. CR(VI) is more stable at higher pH and lower humus content. Thus the reduction much quicker in the upper, weakly acidic top layer. CR(VI) oxidizes the organic matter of soil. The rate of this reaction depends on pH values, the humus content of the soil and temperature. CR(III) leaching in different uncontaminated soils was studied too. There are 3 pathways of mobilization of Cr(III). When pH decreases in soil the CR(III) becomes more soluble, similarly to the aluminium(III) ion. When the soil contains large quantity of water soluble organic ligands, Cr makes complexes with them and complexes formed can be leached out from the top layer. The third possibility is the oxidation of CR(III) to Cr(VI). It could happen on surface of manganese dioxide in the well-aired top layer.

Prokisch, J.; Gyori, Z.; Kovacs, B.; Loch, J. [Debrecen Agricultural Univ. Central Lab. (Hungary)

1995-12-31

225

Soil productivity aspects of agroforestry  

Energy Technology Data Exchange (ETDEWEB)

The booklet comprises 5 chapters: land-use systems related to agroforestry (shifting cultivation, taungya, woody perennial plantation crops, plantation forestry and multiple cropping); The role of trees in soil productivity and conservation; research results from some field examples of agroforestry (hedgerow intercropping - alley cropping, mulch farming, intercropping in plantation crops, integration of trees on farmlands in dry regions); and soil productivity and soil management in agroforestry: some posulations and suggested research approaches.

Nair, P.K.R.

1984-01-01

226

Effect of soil solarization on soil-borne pathogens  

International Nuclear Information System (INIS)

Author.Soil solarization was conducted at three locations on the Lebanese coast. Maximum soil temperatures recorded were 53 and 48 celsius degrees at Jiyeh, 48.9, 46 and 43 celsius degrees at Naameh and 48, 45 and 43.5 celsius degrees at Khaldeh at 5, 15 and 25cm soil depths respectively. Mean soil temperatures recorded at 3pm were at Jiyeh 51.6, 47 and 46 celsius degrees compared to Naameh 47, 45 and 41 celsius degrees and Khaldeh 44, 42 and 41 celsius degrees at 5, 15 and 25 cm respectively. The mean temperature in solarized soils were 7.3 to 15 celsius degrees higher than those of the nonsolarized soils indicating a sustained increase of soil temperature in the solarized soils. The effect of soil solarization on artificially introduced fungal pathogens in the soil at Khaldeh, resulted in complete destruction of sclerotia of Sclerotinia spp. at three depths studied. However, with respect to the two other pathogens tested, solarization resulted in reduction of the viability of microsclerotia of Verticillium spp. by 99-79% and of Fusarium oxysporum f. sp. melonis inoculum by 88-54% at 5 and 15 cm respectively, but only by 45% and 14% reduction at 25 cm. This level of control is significant when it is compared to the percentage of control where the level of reduction of inoculum viability did not exceed 10% at any soil depth. As there were contradicting reports in the literature on nematodes, two field trials in greenhouses were conducted to study the possibility of integrating 2 methods for management on nematodes. Soil solarization alone or in combination with biological control of nematodes using Arthrobotrys spp. and Dactyl ella brocophaga to control the root-knot nematodes on two crops, tomato at Naameh and cucumber at Jiyeh were compared to Methyl Bromide treatment. It was evident that, even on a very susceptible crop like cucumber, the integration of biological control and soil solarization gave a good level of control similar to methyl bromide. Neither root-knot indices nor yields were significantly different in both treatments. At present, fumigation with methyl bromide is the most common method adopted by Lebanese farmers to control soil-borne pathogens of high value crops in greenhouses. Since methyl bromide is extremely toxic and damage the ozone layer, and its use is banned in several countries and may be banned world wide in year 2001, these preliminary results prove that soil solarization may stand as a good alternative control measure

1995-01-01

227

Apollo 11 soil mechanics investigation.  

UK PubMed Central (United Kingdom)

The fine-grained surface material at the Apollo 11 landing site is a brownish, medium-gray, slightly cohesive granular soil, with bulky grains in the silt-to-fine-sand range, having a specific gravity of 3.1 and exhibiting adhesive characteristics. Within the upper few centimeters, the lunar soil has an average density of about 1.6 grams per cubic centimeter and is similar in appearance and behavior to the soils studied at the Surveyor equatorial landing sites. Althouglh considerably different in composition and in range of particle shapes, it is similar in its mechanical behavior to terrestrial soils of the same grain size distribution.

Costes NC; Carrier WD; Mitchell JK; Scott RF

1970-01-01

228

NASIS: National Soil Information System  

Science.gov (United States)

The National Soil Information System (NASIS) plays a role in the National Cooperative Soil Survey's goal of providing an active resource of soils information and "is designed to manage and maintain soil data from collection to dissemination." The website provides information and software downloads needed to access the NASIS system. Visitors can find helpful instructions on how to use the system as well as information on data problems. The website describes new works in progress and future plans. Users also have the opportunity to subscribe to NASISNEWS, the electronic mailing lists for NASIS users.

229

Environmental soil properties and behaviour  

CERN Multimedia

From bridges and tunnels to nuclear waste repositories, structures require that soils maintain their design engineering properties if the structures are to reach their projected life spans. The same is true for earth dams, levees, buffers, barriers for landfills, and other structures that use soils as engineered materials. Yet soil, a natural resource, continues to change as a result of natural and anthropogenic stresses. As the discipline of soil properties and behaviours matures, new tools and techniques are making it possible to study these properties and behaviours in more depth. What Happ

Yong, Raymond N

2012-01-01

230

THE BALANCED ENTROPY INDEX TO CHARACTERIZE SOIL TEXTURE FOR SOIL WATER RETENTION ESTIMATION  

Science.gov (United States)

Pedotransfer procedures are often used to estimate soil hydraulic properties from soil basic data available from soil surveys. Soil particle size distribution, or texture, is known to be a leading soil property affecting soils' ability to retain and transmit water and solutes. A substantial effort h...

231

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 tim...

Abdullah Nishori; Besnik Gjongecaj; Deme Abazi

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

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, ...

234

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 ...

Hanquet, Bernard; Sirjacobs, Damien; Destain, Marie-France; Frankinet, Marc; Verbrugge, Jean-Claude

235

Radioisotopes in soil fertility and soil pollution research  

International Nuclear Information System (INIS)

Radioisotopes from nuclear reactors are very useful research tool for agricultural scientists. The availability of radioisotopes like 32P, 65Zn, 54Mn, etc. made it possible for the researchers to explore investigations on soil fertility, plant macro- and micronutrients. Heavy metal radioisotopes like 115mCd, 51Cr, 75Se, etc. play a significant role in soil pollution research. (author)

2009-10-01

236

Soil fungi as indicators of pesticide soil pollution  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Soil fungi, with their pronounced enzymic activity and high osmotic potential, represent a significant indicator of negative effects of different pesticides on the agroecosystem as a whole. In that respect, a trial was set up on the alluvium soil type with the aim to investigate the effect of differ...

Mandi? Leka; ?uki? Dragutin; ?or?evi? Snežana

237

Soil neutralizing slurries  

UK PubMed Central (United Kingdom)

A stable, homogeneous, and flowable soil neutralizing slurry of particulate material such as calcium carbonate or dolomitic lime as provided using a suspending agent and a dispersant. A polyanionic dispersant is used in limited quantities to increase the concentration of particulate material and a gelling grade clay mineral is used as a suspending agent to prevent settling of the dispersed particulate material. A partial dispersion technique is used whereby the amount of dispersant used is limited so that the particulate material is dispersed but not the clay mineral.

SAWYER JR EDGAR W

238

Saxton soil remediation project  

Energy Technology Data Exchange (ETDEWEB)

The Saxton Nuclear Experimental Facility (SNEF) consists of a 23-MW(thermal) pressurized light water thermal reactor located in south central Pennsylvania. The Saxton Nuclear Experimental Corporation (SNEC), a wholly owned subsidiary of the General Public Utilities (GPU) Corporation, is the licensee for the SNEF. Maintenance and decommissioning activities at the site are conducted by GPU Nuclear, also a GPU subsidiary and operator of the Three Mile Island and Oyster Creek nuclear facilities. The remediation and radioactive waste management of contaminated soils is described.

Holmes, R.D. [GPU Nuclear Corporation, Middletown, PA (United States)

1995-12-31

239

Manufactured soil screening test  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this technical note is to provide a screening test that can be used to evaluate the potential for manufacturing artificial soil using dredged material, cellulose waste materials (e.g., yard waste compost, sawdust, wastepaper), and biosolids (e.g., N-Viro-reconditioned sewage sludge, BIONSOIL-reconstituted cow manure). This procedure will allow the most productive blend of any dredged material (uncontaminated or contaminated), cellulose, and biosolids to be determined and recommended for use in an environmentally productive and beneficial manner.

NONE

1999-05-01

240

Wetting properties of fungi mycelium alter soil infiltration and soil water repellency in a ?-sterilized wettable and repellent soil.  

UK PubMed Central (United Kingdom)

Soil water repellency (SWR) has a drastic impact on soil quality resulting in reduced infiltration, increased runoff, increased leaching, reduced plant growth, and increased soil erosion. One of the causes of SWR is hydrophobic fungal structures and exudates that change the soil-water relationship. The objective of this study was to determine whether SWR and infiltration could be manipulated through inoculation with fungi. The effect of fungi on SWR was investigated through inoculation of three fungal strains (hydrophilic -Fusarium proliferatum, chrono-amphiphilic -Trichoderma harzianum, and hydrophobic -Alternaria sp.) on a water repellent soil (WR-soil) and a wettable soil (W-soil). The change in SWR and infiltration was assessed by the water repellency index and cumulative infiltration respectively. F. proliferatum decreased the SWR on WR-soil and slightly increased SWR in W-soil, while Alternaria sp. increased SWR in both the W-soil and the WR-soil. Conversely T. harzianum increased the SWR in the W-soil and decreased the SWR in the WR-soil. All strains showed a decrease in infiltration in W-soil, while only the F. proliferatum and T. harzianum strain showed improvement in infiltration in the WR-soil. The ability of fungi to alter the SWR and enmesh soil particles results in changes to the infiltration dynamics in soil.

Chau HW; Goh YK; Vujanovic V; Si BC

2012-12-01

 
 
 
 
241

Wetting properties of fungi mycelium alter soil infiltration and soil water repellency in a ?-sterilized wettable and repellent soil.  

Science.gov (United States)

Soil water repellency (SWR) has a drastic impact on soil quality resulting in reduced infiltration, increased runoff, increased leaching, reduced plant growth, and increased soil erosion. One of the causes of SWR is hydrophobic fungal structures and exudates that change the soil-water relationship. The objective of this study was to determine whether SWR and infiltration could be manipulated through inoculation with fungi. The effect of fungi on SWR was investigated through inoculation of three fungal strains (hydrophilic -Fusarium proliferatum, chrono-amphiphilic -Trichoderma harzianum, and hydrophobic -Alternaria sp.) on a water repellent soil (WR-soil) and a wettable soil (W-soil). The change in SWR and infiltration was assessed by the water repellency index and cumulative infiltration respectively. F. proliferatum decreased the SWR on WR-soil and slightly increased SWR in W-soil, while Alternaria sp. increased SWR in both the W-soil and the WR-soil. Conversely T. harzianum increased the SWR in the W-soil and decreased the SWR in the WR-soil. All strains showed a decrease in infiltration in W-soil, while only the F. proliferatum and T. harzianum strain showed improvement in infiltration in the WR-soil. The ability of fungi to alter the SWR and enmesh soil particles results in changes to the infiltration dynamics in soil. PMID:23245615

Chau, Henry Wai; Goh, Yit Kheng; Vujanovic, Vladimir; Si, Bing Cheng

2012-11-07

242

Relating soil biochemistry to sustainable crop production  

Science.gov (United States)

Amino acids, amino sugars, carbohydrates, phenols, and fatty acids together comprise appreciable proportions of soil organic matter (SOM). Their cycling contribute to soil processes, including nitrogen availability, carbon sequestration and aggregation. For example, soil accumulation of phenols has ...

243

METHOD TO PREPARE SOIL FOR SEEDING  

UK PubMed Central (United Kingdom)

A method to prepare soil for seeding relates to agriculture, in particular to applying the required amount of effective microorganisms and other preparations into soil in the process of soil preparation to seeding.

BOIKO VOLODYMYR SEMENOVYCH; KAIRA MYKOLA IVANOVYCH; ARTEMENKO VOLODYMYR IVANOVYCH; RIABTSEV MYKOLA PETROVYCH; ZAIKA VOLODYMYR YAKOVYCH; KABANTSEV HRYHORII HRYHOROVYCH; RIABTSEV PETRO MYKOLAIOVYCH; SHERDYTS HEORHII HEORHIIOVYCH

244

Soil sampling for environmental contaminants  

International Nuclear Information System (INIS)

The Consultants Meeting on Sampling Strategies, Sampling and Storage of Soil for Environmental Monitoring of Contaminants was organized by the International Atomic Energy Agency to evaluate methods for soil sampling in radionuclide monitoring and heavy metal surveys for identification of punctual contamination (hot particles) in large area surveys and screening experiments. A group of experts was invited by the IAEA to discuss and recommend methods for representative soil sampling for different kinds of environmental issues. The ultimate sinks for all kinds of contaminants dispersed within the natural environment through human activities are sediment and soil. Soil is a particularly difficult matrix for environmental pollution studies as it is generally composed of a multitude of geological and biological materials resulting from weathering and degradation, including particles of different sizes with varying surface and chemical properties. There are so many different soil types categorized according to their content of biological matter, from sandy soils to loam and peat soils, which make analytical characterization even more complicated. Soil sampling for environmental monitoring of pollutants, therefore, is still a matter of debate in the community of soil, environmental and analytical sciences. The scope of the consultants meeting included evaluating existing techniques with regard to their practicability, reliability and applicability to different purposes, developing strategies of representative soil sampling for cases not yet considered by current techniques and recommending validated techniques applicable to laboratories in developing Member States. This TECDOC includes a critical survey of existing approaches and their feasibility to be applied in developing countries. The report is valuable for radioanalytical laboratories in Member States. It would assist them in quality control and accreditation process

2004-01-01

245

Continuous soil monitoring and inventory of soils as part of the soil information system  

International Nuclear Information System (INIS)

The Bavarian Geological State office conducted a soil inventory and continuous soil monitoring programme. In order to make permanent monitoring feasible the Bavarian Geological State office developed a special concept. This concept of site selection, commissioning, sampling and analysis is described in this paper. The results of first studies of the three permanent soil monitoring areas in the Alpine region shows that only on the Gotzenalm in the national park in Berchtegaden there are significant accumulations of Cs-137 and of some other typically anthropogenic heavy metals in the top soil. Organic pollution is small in all three areas. (orig./EW)

1993-01-01

246

Soil properties related to 60Co bioavailability in tropical soils  

International Nuclear Information System (INIS)

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

2005-09-02

247

Estimating soil organic carbon from soil reflectance: a review  

UK PubMed Central (United Kingdom)

Soil organic carbon (SOC) concentration is a useful soil property with which to guide agricultural applications of chemical inputs. To enable this, simple, accurate, rapid and inexpensive methods are needed to produce maps of surface SOC concentrations. Researchers have investigated estimates of soil surface properties from remotely sensed information as a means of rapidly quantifying and monitoring some surface soil properties, such as SOC. The objective of this paper is to review the potential and limitations of remotely sensed data for mapping and evaluating SOC. Several statistical methods including simple regression models, the ‘soil line' approach, principal component analysis and geostatistics have been applied to data to investigate the accuracy of such estimates. A review of the literature shows that predictive equations are not universal and require new regression models for every scene. An important benefit of remotely sensed data is to suggest a sampling strategy that can lead to improved representation of spatial heterogeneity in SOC.

Ladoni Moslem; Bahrami HoseinAli; Alavipanah SayedKazem; Norouzi AliAkbar

2010-02-01

248

Soil fungi as indicators of pesticide soil pollution  

Directory of Open Access Journals (Sweden)

Full Text Available Soil fungi, with their pronounced enzymic activity and high osmotic potential, represent a significant indicator of negative effects of different pesticides on the agroecosystem as a whole. In that respect, a trial was set up on the alluvium soil type with the aim to investigate the effect of different herbicides (Simazine, Napropamid, Paraquat), fungicides (Captan and Mancozeb) and insecticides (Fenitrothion and Dimethoate) on a number of soil fungi under apple trees. The number of soil fungi was determined during four growing seasons by an indirect method of dilution addition on the Czapek agar. The study results indicate that the fungi belong to the group of microorganisms that, after an initial sensible response to the presence of pesticides in the soil, very rapidly establish normal metabolism enabling them even to increase their number. The fungicides and insecticides applied were found to be particularly effective in that respect.

Mandi? Leka; ?uki? Dragutin; ?or?evi? Snežana

2005-01-01

249

Temperature sensitivity of soil organic matter decomposition in boreal soils  

Energy Technology Data Exchange (ETDEWEB)

The temperature sensitivity of decomposition of different soil organic matter (SOM) fractions was studied with laboratory incubations using C-13 and C-14 isotopes to differentiate between SOM of different age. The quality of SOM and the functionality and composition of microbial communities in soils formed under different climatic conditions were also studied. Transferring of organic layers from a colder to a warmer climate was used to assess how changing climate, litter input and soil biology will affect soil respiration and its temperature sensitivity. Together, these studies gave a consistent picture on how warming climate will affect the decomposition of different SOM fractions in Finnish forest soils: the most labile C was least temperature sensitive, indicating that it is utilized irrespective of temperature. The decomposition of intermediate C, with mean residence times from some years to decades, was found to be highly temperature sensitive. Even older, centennially cycling C was again less temperature sensitive, indicating that different stabilizing mechanisms were limiting its decomposition even at higher temperatures. Because the highly temperature sensitive, decadally cycling C, forms a major part of SOM stock in the organic layers of the studied forest soils, these results mean that these soils could lose more carbon during the coming years and decades than estimated earlier. SOM decomposition in boreal forest soils is likely to increase more in response to climate warming, compared to temperate or tropical soils, also because the Q10 is temperature dependent. In the northern soils the warming will occur at a lower temperature range, where Q10 is higher, and a similar increase in temperature causes a higher relative increase in respiration rates. The Q10 at low temperatures was found to be inversely related to SOM quality. At higher temperatures respiration was increasingly limited by low substrate availability. (orig.)

Karhu, K.

2010-07-01

250

Soil classification and radionuclide migration in west Cumbrian soils  

International Nuclear Information System (INIS)

Radionuclide migration through soil is controlled by the degree of retardation due to sorption of the radionuclide onto the soil, which is dependant upon the soil type and nuclide involved. It is therefore important to assess the soil variability of the geographical area under study. Radionuclide attenuation is usually quantified by a distribution coefficient (Kd) or distribution ratio (Rd) obtained from batch experiments. As part of this research Rd values were compared with column retardation factors (Rf values) in order to assess how closely Rd values relate to radionuclide migration in an undisturbed soil. Results of this research have shown that the method and conditions used to conduct batch experiments can greatly affect the Kd and Rd values obtained. Rd values for a range of west Cumbrian soils were generally of the order 137Cs>60Co>125Sb>85Sr. The use of the national soil map of England and Wales (Jarvis et al., 1984) was not recommended for prediction of radionuclide migration in west Cumbrian soils. It was suggested that an Rd values for each major soil type (sand, clay, loam and peat) was sufficient for use in assessment studies. Modifications made to the batch method in this project did not appear to reduce the discrepancy which is often reported between batch and column retardation parameters. In general, the majority of the batch and column Rd values obtained in this research differed by one order of magnitude. There did not appear to be any trend, with regard to nuclide or soil type, in determining the magnitude by which the batch and column Rd values differed. Using the measured Rd values as input parameters in an advection-diffusion model produced mixed results, but the predicted activity-depth profiles generally underestimated the depths to which the radionuclides migrated down the column. (author)

2000-01-01

251

Soil invertebrate fauna affect N2 O emissions from soil.  

UK PubMed Central (United Kingdom)

Nitrous oxide (N2 O) emissions from soils contribute significantly to global warming. Mitigation of N2 O emissions is severely hampered by a lack of understanding of its main controls. Fluxes can only partly be predicted from soil abiotic factors and microbial analyses - a possible role for soil fauna has until now largely been overlooked. We studied the effect of six groups of soil invertebrate fauna and tested the hypothesis that all of them increase N2 O emissions, although to different extents. We conducted three microcosm experiments with sandy soil and hay residue. Faunal groups included in our experiments were as follows: fungal-feeding nematodes, mites, springtails, potworms, earthworms and isopods. In experiment I, involving all six faunal groups, N2 O emissions declined with earthworms and potworms from 78.4 (control) to 37.0 (earthworms) or 53.5 (potworms) mg N2 O-N m(-2) . In experiment II, with a higher soil-to-hay ratio and mites, springtails and potworms as faunal treatments, N2 O emissions increased with potworms from 51.9 (control) to 123.5 mg N2 O-N m(-2) . Experiment III studied the effect of potworm density; we found that higher densities of potworms accelerated the peak of the N2 O emissions by 5 days (P < 0.001), but the cumulative N2 O emissions remained unaffected. We propose that increased soil aeration by the soil fauna reduced N2 O emissions in experiment I, whereas in experiment II N2 O emissions were driven by increased nitrogen and carbon availability. In experiment III, higher densities of potworms accelerated nitrogen and carbon availability and N2 O emissions, but did not increase them. Overall, our data show that soil fauna can suppress, increase, delay or accelerate N2 O emissions from soil and should therefore be an integral part of future N2 O studies.

Kuiper I; de Deyn GB; Thakur MP; van Groenigen JW

2013-09-01

252

Soil invertebrate fauna affect N2 O emissions from soil.  

Science.gov (United States)

Nitrous oxide (N2 O) emissions from soils contribute significantly to global warming. Mitigation of N2 O emissions is severely hampered by a lack of understanding of its main controls. Fluxes can only partly be predicted from soil abiotic factors and microbial analyses - a possible role for soil fauna has until now largely been overlooked. We studied the effect of six groups of soil invertebrate fauna and tested the hypothesis that all of them increase N2 O emissions, although to different extents. We conducted three microcosm experiments with sandy soil and hay residue. Faunal groups included in our experiments were as follows: fungal-feeding nematodes, mites, springtails, potworms, earthworms and isopods. In experiment I, involving all six faunal groups, N2 O emissions declined with earthworms and potworms from 78.4 (control) to 37.0 (earthworms) or 53.5 (potworms) mg N2 O-N m(-2) . In experiment II, with a higher soil-to-hay ratio and mites, springtails and potworms as faunal treatments, N2 O emissions increased with potworms from 51.9 (control) to 123.5 mg N2 O-N m(-2) . Experiment III studied the effect of potworm density; we found that higher densities of potworms accelerated the peak of the N2 O emissions by 5 days (P < 0.001), but the cumulative N2 O emissions remained unaffected. We propose that increased soil aeration by the soil fauna reduced N2 O emissions in experiment I, whereas in experiment II N2 O emissions were driven by increased nitrogen and carbon availability. In experiment III, higher densities of potworms accelerated nitrogen and carbon availability and N2 O emissions, but did not increase them. Overall, our data show that soil fauna can suppress, increase, delay or accelerate N2 O emissions from soil and should therefore be an integral part of future N2 O studies. PMID:23625707

Kuiper, Imke; de Deyn, Gerlinde B; Thakur, Madhav P; van Groenigen, Jan Willem

2013-07-14

253

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 ...

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

254

METHOD FOR CONTROLLING SOIL INSECTS  

UK PubMed Central (United Kingdom)

The subject matter of the invention is the use, by burial in the soil, of a composition based on pyrethrum, with the exception of tefluthrin and of bifenthrin, and a method of controlling soil insects using said pyrethrum-based composition.

PEYRON XAVIER

255

Geotechnical characteristics of residual soils  

Energy Technology Data Exchange (ETDEWEB)

Residual soils are products of chemical weathering and thus their characteristics are dependent upon environmental factors of climate, parent material, topography and drainage, and age. These conditions are optimized in the tropics where well-drained regions produce reddish lateritic soils rich in iron and aluminum sesquioxides and kaolinitic clays. Conversely, poorly drained areas tend towards montmorillonitic expansive black clays. Andosols develop over volcanic ash and rock regions and are rich in allophane (amorphous silica) and metastable halloysite. The geological origins greatly affect the resulting engineering characteristics. Both lateritic soils and andosols are susceptible to property changes upon drying, and exhibit compaction and strength properties not indicative of their classification limits. Both soils have been used successfully in earth dam construction, but attention must be given to seepage control through the weathered rock. Conversely, black soils are unpopular for embankments. Lateritic soils respond to cement stabilization and, in some cases, lime stabilization. Andosols should also respond to lime treatment and cement treatments if proper mixing can be achieved. Black expansive residual soils respond to lime treatment by demonstrating strength gains and decreased expansiveness. Rainfall induced landslides are typical of residual soil deposits.

Townsend, F.C.

1985-01-01

256

Water, Air and Soil Pollution ?????????  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Water, Air, & Soil Pollution is an international, interdisciplinary journal covering all aspects of pollution and solutions to pollution in the biosphere. This includes chemical, physical and biological processes affecting flora, fauna, water, air and soil. Coverage is diverse and includes al...

257

Australian Journal of Soil Research ??????????  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The Australian Journal of Soil Research is an international journal for the publication of soil research relating to primary production, land and water management, environmental pollution, and site remediation. The journal has a particular, but not exclusive, focus on research that promotes u...

258

Estimation of soil nitrogen availability  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 wh...

Kresovi? Mirjana M.; Li?ina V.

259

Semiarid soil and water conservation  

Energy Technology Data Exchange (ETDEWEB)

This book provides an overview of soil and water conservation and emphasizes practical control measures. Contents include surface hydrology, analysis of the erosion process, and practical control measures through: correct land use; crop rotations; shifting cultivation; contour farming; and strip cropping; Water harvesting, recently developed systems now in use, and rangeland management for soil and water conservation in semi-arid regions are reviewed.

Finkel, H.J.

1986-01-01

260

Uptake of radionuclides from soil  

International Nuclear Information System (INIS)

Experiments to determine the transfer factors for the radionuclides 90Sr, 139Cs, 60Co, and 54Mn have been carried out at Juelich research centre since June 1978. A temporary soil contamination caused by an accident (radionuclides entering the 0 to 1 cm soil layer) and a continuous soil contamination (radionuclides entering the 0 to 20 cm topsoil, AP horizon) are simulated. The test plants are agricultural plants such as alfalfa, mixtures of meadow grass, potatoes, sugar beets, winter wheat, spring barley, and clover. If crop rotation on specific soil permits it, also garden cultures such as lettuce, radishes, carrots, and dwarf beans are grown. Preliminary results of the first vegetation period show a wide variation of transfer factors for the radionuclides under investigation in dependence of the type of soil and plant. These variations and the specific dependence of transfer factors on certain soil properties, on the type of plant and its stage of growth at the time of harvesting, on the part of the plant, and on the experimental conditions set a limit to the establishment of a transfer factor to predict the concentration of a radionuclide in a certain plant in a certain soil. Still, it may be possible to give conservative transfer factors for certain types of soil and for the most common crops. (orig.).

1979-10-03

 
 
 
 
261

Bottom ash boosts poor soil  

Energy Technology Data Exchange (ETDEWEB)

This article describes agricultural uses of fluidized bed bottom ash residue from burning limestone and coal in electric power generating plants: as a limestone substitute, to increase calcium levels in both soil and plants, and as a gypsom-containing soil amendment. Apples and tomatoes are the crops used. The industrial perspective and other uses of bottom ash are also briefly described.

Stanley, D.

1993-04-01

262

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

263

Soil and its responses to acid deposition  

Energy Technology Data Exchange (ETDEWEB)

This article consders whether acid precipitation is acidifying soil. The possible consequences of soil acidification are outlined. Soils, soil development, concepts of cation exchange capacity, base saturation, and weathering are described. The theory of soil acidification is presented, these conditions are met by acid precipitation and natural soil acid processes counterbalanced by weathering, sulphate absorption and liming. Evidence that high acid deposition has caused soil acidifications is presented along with equivocal evidence for regions of lower deposition. Simulation modelling may eventually allow reasonable predictions about the future course of soil acidification. 24 refs.

Skeffington, R.A.

1987-08-01

264

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

265

Soil Properties Controlling Zn Speciation and Fractionation in Contaminated Soils  

Energy Technology Data Exchange (ETDEWEB)

We determined the speciation of Zn in 49 field soils differing widely in pH (4.1-7.7) and total Zn content (251-30,090 mg/kg) by using extended X-ray absorption fine structure (EXAFS) spectroscopy. All soils had been contaminated since several decades by inputs of aqueous Zn with runoff-water from galvanized power line towers. Pedogenic Zn species identified by EXAFS spectroscopy included Zn in hydroxy-interlayered minerals (Zn-HIM), Zn-rich phyllosilicates, Zn-layered double hydroxide (Zn-LDH), hydrozincite, and octahedrally and tetrahedrally coordinated sorbed or complexed Zn. Zn-HIM was only observed in (mostly acidic) soils containing less than 2000 mg/kg of Zn, reflecting the high affinity but limited sorption capacity of HIM. Zn-bearing precipitates, such as Zn-LDH and Zn-rich trioctahedral phyllosilicates, became more dominant with increasing pH and increasing total Zn content relative to available adsorption sites. Zn-LDH was the most abundant Zn-precipitate and was detected in soils with pH > 5.2. Zn-rich phyllosilicates were detected even at lower soil pH, but were generally less abundant than Zn-LDH. Hydrozincite was only identified in two calcareous soils with extremely high Zn contents. In addition to Zn-LDH, large amounts of Zn in highly contaminated soils were mainly accumulated as sorbed/complexed Zn in tetrahedral coordination. Soils grouped according to their Zn speciation inferred from EXAFS spectroscopy mainly differed with respect to soil pH and total Zn content. Clear differences were observed with respect to Zn fractionation by sequential extraction: From Zn-HIM containing soils, most of the total Zn was recovered in the exchangeable and the most recalcitrant fractions. In contrast, from soils containing the highest percentage of Zn-precipitates, Zn was mainly extracted in intermediate extraction steps. The results of this study demonstrate that soil pH and Zn contamination level relative to available adsorption sites are the most important factors controlling the formation of pedogenic Zn-species in aerobic soils and, consequently, Zn fractionation by sequential extraction.

Jacquat, O.; Voegelin, A; Kretzschmar, R

2009-01-01

266

Shrinkage limit of soil mixtures  

Energy Technology Data Exchange (ETDEWEB)

Shrinkage limit, one of the Atterberg limits, is widely linked with many plasticity-based soil behaviors. However, in a great majority of these cases, such correlations have been found to exhibit poor performance. Recently, it has been brought out that the shrinkage limit of a natural soil does not depend upon plasticity characteristics, and it is primarily governed by the relative grain size distribution of the soil. The present study confirms this mechanism with the results obtained using clay-clay, clay-non-cohesive soil, and non-cohesive soil mix systems. The present study gains importance from the point of view of criteria with respect to the design of back fill materials to be used in various applications, such as nuclear waste disposal projects.

Sridharan, A.; Prakash, K.

2000-03-01

267

Shrinkage limit of soil mixtures  

International Nuclear Information System (INIS)

Shrinkage limit, one of the Atterberg limits, is widely linked with many plasticity-based soil behaviors. However, in a great majority of these cases, such correlations have been found to exhibit poor performance. Recently, it has been brought out that the shrinkage limit of a natural soil does not depend upon plasticity characteristics, and it is primarily governed by the relative grain size distribution of the soil. The present study confirms this mechanism with the results obtained using clay-clay, clay-non-cohesive soil, and non-cohesive soil mix systems. The present study gains importance from the point of view of criteria with respect to the design of back fill materials to be used in various applications, such as nuclear waste disposal projects.

2000-01-01

268

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.

David Pimentel; Michael Burgess

2013-01-01

269

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; J.F.N. Abowei

2011-01-01

270

Soil management impacts on soil carbon sequestration by switchgrass  

Energy Technology Data Exchange (ETDEWEB)

Increased atmospheric carbon dioxide (CO{sub 2}) could have negative impacts on the environment. Producing and creating bioenergy in the form of biofuels and electricity from crops is a practical approach to reducing CO{sub 2} buildup by displacing fossil fuels and sequestering carbon (C). The use of switchgrass (Panicum virgatum L.) as an energy crop can contribute to clean burning fuels, but no studies addressing soil C sequestration as influenced by use of switchgrass as an energy crop have been conducted. Our objective was to determine the effect of different cultural practices on soil C sequestration under switchgrass. Field experiments were designed to provide differences in row spacing, nitrogen (N) rate, switchgrass cultivar, and harvest frequency on a variety of soils. Our results showed that N application, row spacing, harvest frequency, and switchgrass cultivar did not change soil organic C in the short-term (2-3 yr) after switchgrass establishment. However, after 10 yr under switchgrass soil organic C was 45 and 28% higher at depths of 0-15 and 15-30 cm, respectively, compared with fallowed soil in an adjacent area. It appears that several years of switchgrass culture will be required to realize a soil C sequestration benefit. (author)

Ma, Z.; Wood, C.W.; Bransby, D.I. [Auburn University (United States). Dept. of Agronomy and Soils

2000-07-01

271

Soil-solution speciation of Cd as affected by soil characteristics in unpolluted and polluted soils  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Total metal content by itself is insufficient as a measure to indicate actual environmental risk. Understanding the mobility of heavy metals in the soil and their speciation in the soil solution is of great importance for accurately assessing environmental risks posed by these metals. In a first exp...

MEERS, Erik; Unamuno, V; Vandegehuchte, M; Vanbroekhoven, K; GEEBELEN, Wouter; Samson, R; VANGRONSVELD, Jaco; Diels, L

272

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

273

Biogeochemical interfaces in soil: The interdisciplinary challenge for soil science  

UK PubMed Central (United Kingdom)

Soil, the "Earth's thin skin" serves as the delicate interface between the biosphere, hydrosphere, atmosphere, and lithosphere. It is a dynamic and hierarchically organized system of various organic and inorganic constituents and organisms, the spatial structure of which defines a large, complex, and heterogeneous interface. Biogeochemical processes at soil interfaces are fundamental for the overall soil development, and they are the primary driving force for key ecosystem functions such as plant productivity and water quality. Ultimately, these processes control the fate and transport of contaminants and nutrients into the vadose zone and as such their biogeochemical cycling. The definite objective in biogeochemical-interface research is to gain a mechanistic understanding of the architecture of these biogeochemical interfaces in soils and of the complex interplay and interdependencies of the physical, chemical, and biological processes acting at and within these dynamic interfaces in soil. The major challenges are (1) to identify the factors controlling the architecture of biogeochemical interfaces, (2) to link the processes operative at the individual molecular and/or organism scale to the phenomena active at the aggregate scale in a mechanistic way, and (3) to explain the behavior of organic chemicals in soil within a general mechanistic framework. To put this in action, integration of soil physical, chemical, and biological disciplines is mandatory. Indispensably, it requires the adaption and development of characterization and probing techniques adapted from the neighboring fields of molecular biology, analytical and computational chemistry as well as materials and nano-sciences. To shape this field of fundamental soil research, the German Research Foundation (DFG) has granted the Priority Program "Biogeochemical Interfaces in Soil", in which 22 individual research projects are involved.

Totsche KaiU; Rennert Thilo; Gerzabek MartinH; Kögel-Knabner Ingrid; Smalla Kornelia; Spiteller Michael; Vogel Hans-Jörg

2010-02-01

274

ESTIMATING SOIL PARTICLE-SIZE DISTRIBUTION FOR SICILIAN SOILS  

Directory of Open Access Journals (Sweden)

Full Text Available The soil particle-size distribution (PSD) is commonly used for soil classification and for estimating soil behavior. An accurate mathematical representation of the PSD is required to estimate soil hydraulic properties and to compare texture measurements from different classification systems. The objective of this study was to evaluate the ability of the Haverkamp and Parlange (HP) and Fredlund et al. (F) PSD models to fit 243 measured PSDs from a wide range of 38 005_Bagarello(547)_33 18-11-2009 11:55 Pagina 38 soil textures in Sicily and to test the effect of the number of measured particle diameters on the fitting of the theoretical PSD. For each soil textural class, the best fitting performance, established using three statistical indices (MXE, ME, RMSE), was obtained for the F model with three fitting parameters. In particular, this model performed better in the fine-textured soils than the coarse-textured ones but a good performance (i.e., RMSE < 0.03) was detected for the majority of the investigated soil textural classes, i.e. clay, silty-clay, silty-clay-loam, silt-loam, clay-loam, loamy-sand, and loam classes. Decreasing the number of measured data pairs from 14 to eight determined a worse fitting of the theoretical distribution to the measured one. It was concluded that the F model with three fitting parameters has a wide applicability for Sicilian soils and that the comparison of different PSD investigations can be affected by the number of measured data pairs.

Vincenzo Bagarello; Vito Ferro; Giuseppe Giordano

2009-01-01

275

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

276

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

277

Can we predict uranium bioavailability based on soil parameters? Part 1: Effect of soil parameters on soil solution uranium concentration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Present study aims to quantify the influence of soil parameters on soil solution uranium concentration for U-238 spiked soils. Eighteen soils collected under pasture were selected such that they covered a wide range for those parameters hypothesised as being potentially important in determining U so...

Vandenhove, H.; Van Hees, M.; WOUTERS, Kristien; Wannijn, J.

278

Sunlight in the soil  

Energy Technology Data Exchange (ETDEWEB)

A method, developed by the Scandinavians, is described for using absorption of solar heat by the earth to heat homes. Flexible plastic piping, buried in the ground adjacent to the home, is used to pick up heat from the soil and subsurface water and carry the heat to a heat pump in the house. The system, costing approximately $8500 (including excavation), is reported to achieve a seasonal heating efficiency of 300% compared to 85-90% for highly efficient gas furnaces. The system can be connected to existing radiators or forced air ducts and can be used to heat domestic hot water supplies. The commercial name of the system is ''Cantherm''.

Rawlings, R.

1984-02-01

279

Geochemistry - Soils Analysis  

Science.gov (United States)

Students conduct a geochemical analysis of a soil. Each group chooses one of the following analyses: conductivity buffer solution, conductivity, acidity, mineralogy, grain size, or loss on ignition. As this lab falls somewhere between the middle and end of the course, students are versed in various chemical methods. This lab reinforces those skills while forcing students to organize their time and be patient with each other while conducting careful lab science. The samples used for this lab were from a Bronze-Age archaeological site in Kazakhstan, but any samples could be substituted. To encourage free-thinking concerning their representations (and interpretations in the follow-up lab), as little background information as possible was given.

Fadem, Cynthia

280

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.; Li?ina V.

2003-01-01

 
 
 
 
281

Decay characteristics of soil thermoluminescence  

International Nuclear Information System (INIS)

Thermoluminescent decay of five different types of soils (soil no. 4FF, Yolo sandy loam, Hanford sandy loam, soil no. 9RDG, and Egbert muck) irradiated by 60Co photons and in the reactor was examined. Although the glow output and the glow curve shapes differed considerably among the soils, the shape of the thermoluminescent decay curves, in general, was quite similar, whether the soil was irradiated by 60Co photons or in the reactor. Regardless of the soil type, the most rapid decay occurred within the first 24 hr after irradiation. After the lapse of sufficient decay time, an apparent isothermal equilibrium state was approached. Curves were fitted to the decay data by the use of a computer program which obtains a weighted least squares fit of a function to the data by means of stepwise Gauss-Newton iterations on the parameters. The results indicated that the thermoluminescent decay curves of soils were hyperbolic [Y= ?(? + X)/sup gamma/ + delta] in form. (U.S.).

1975-01-01

282

Controlling action of soil organic matter on soil moisture retention and its availability  

Directory of Open Access Journals (Sweden)

Full Text Available Aims Assessment of the ecological benefits of forest in soil water retention based on conventionally monitored factors and exploration of the relation between forest carbon-sink function and hydrological benefits has special meaning in Millennium Ecosystem Assessment. Our objectives were to 1) characterize the spatial and temporal variations of soil moisture in three subtropical forests and 2) determine the controlling action of soil organic matter on soil moisture retention during vegetation succession.Methods Standard plots were established in Pinus massonniana coniferous forest (PF), mixed Pinus massonniana-broad-leaved forest (PBF) and monsoon evergreen broad-leaved forest (MBF). We measured soil water content every 10 days from 2002 to 2008 using neutron probes and analyzed soil organic matter content in the laboratory by the potassium dichromate oxidation method.Important findings With natural succession from planted PF to climax MBF, soil water content (0–30 cm soil layer) increased significantly; soil water content was highest in MBF and lowest in PBF. The distribution patterns of soil moisture in the three forests were different: the soil moisture of MBF decreased with soil depth, was more homogeneous in the soil profile in PBF and was lower at the surface than in deeper layers in PF. The soil water characteristic curves showed that under the same matrix suction the magnitude of soil water content (0–40 cm soil layer) was: MBF > PBF > PF; the soil of MBF was the most retentive. Further analysis indicated that soil porosity had the greatest impact on soil moisture, followed by saturated soil water content and soil organic matter content, while soil bulk density had a minimal impact. In the process of natural succession, soil moisture was significantly correlated with the soil organic matter content (p = 0.014), as the soil organic matter could affect soil moisture holding (p = 0.030). Accordingly, we recommend soil organic matter as an effective and integrated index for appraising forest ecosystem services.

LIU Xiao-Dong; QIAO Yu-Na; ZHOU Guo-Yi

2011-01-01

283

Improvement of anaerobic soil disinfestation.  

UK PubMed Central (United Kingdom)

With increasing worldwide restrictions for soil fumigants, growers loose an important tool to control soilborne pests and pathogens. Environmentally friendly alternatives are urgently needed and anaerobic soil disinfestation (ASD) may be one of them. Traditional ASD with fresh grass is already applied in open field vegetables but the mode of action is unknown. Therefore, trials were performed under controlled conditions using soil-filled buckets, in which several processed defined organic materials were incorporated and compared with fresh grass. The effect of inundation was also studied. Target organisms were Pratylenchus penetrans, Meloidogyne hapla, Globodera pallida and Verticillium dahliae. Results showed that grass (traditional ASD) was less effective than the organic materials. All materials proved to be effective at 16 degrees C against all target organisms. However, exposure time, dosages, soil type and the temperature at which the experiments were performed influenced the effectiveness. P. penetrans was eliminated most easily whereas V. dahliae was most difficult to control. Efficacy was higher in sandy soil than in light marine clay. Inundation at 16 degrees C proved to be effective against P. penetrans and G. pallida in both soil types at sufficient exposure times. A soil temperature of 8 degrees C was sometimes too low for efficacy. Gas production of CO2, NH3, H2S, CH4 and N2O and gas consumption of O2 and production of fatty acids during ASD proved to depend on type of organic materials, soil type, temperature, dosage and exposure time. This first step in unravelling the mode of action has already shown several critical parameters for efficacy. Additional knowledge about the complete mechanisms of action may lead to a more reliable, effective and quicker soil disinfestation.

Runia WT; Molendirk LP; Ludeking DJ; Schomaker CH

2012-01-01

284

Improvement of anaerobic soil disinfestation.  

Science.gov (United States)

With increasing worldwide restrictions for soil fumigants, growers loose an important tool to control soilborne pests and pathogens. Environmentally friendly alternatives are urgently needed and anaerobic soil disinfestation (ASD) may be one of them. Traditional ASD with fresh grass is already applied in open field vegetables but the mode of action is unknown. Therefore, trials were performed under controlled conditions using soil-filled buckets, in which several processed defined organic materials were incorporated and compared with fresh grass. The effect of inundation was also studied. Target organisms were Pratylenchus penetrans, Meloidogyne hapla, Globodera pallida and Verticillium dahliae. Results showed that grass (traditional ASD) was less effective than the organic materials. All materials proved to be effective at 16 degrees C against all target organisms. However, exposure time, dosages, soil type and the temperature at which the experiments were performed influenced the effectiveness. P. penetrans was eliminated most easily whereas V. dahliae was most difficult to control. Efficacy was higher in sandy soil than in light marine clay. Inundation at 16 degrees C proved to be effective against P. penetrans and G. pallida in both soil types at sufficient exposure times. A soil temperature of 8 degrees C was sometimes too low for efficacy. Gas production of CO2, NH3, H2S, CH4 and N2O and gas consumption of O2 and production of fatty acids during ASD proved to depend on type of organic materials, soil type, temperature, dosage and exposure time. This first step in unravelling the mode of action has already shown several critical parameters for efficacy. Additional knowledge about the complete mechanisms of action may lead to a more reliable, effective and quicker soil disinfestation. PMID:23885444

Runia, W T; Molendirk, L P G; Ludeking, D J W; Schomaker, C H

2012-01-01

285

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.

Robert Pallasser; Budiman Minasny; Alex B. McBratney

2013-01-01

286

Soil carbon determination by thermogravimetrics.  

UK PubMed Central (United Kingdom)

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.

Pallasser R; Minasny B; McBratney AB

2013-01-01

287

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

288

Analysis of soils - Part I: Soil dynamics and climatic change  

Energy Technology Data Exchange (ETDEWEB)

The reaction of soil characteristics to vegetative alterations as a simulation of the effects of a climatic change are investigated, because the organic matter of soils reflects the condition of nature. The search for suitable acreages is a basic condition, since the stage of being fallow, i.e. the time since the last agricultural use, is supposed to be the only variable. That is why a test area has to fulfil different criteria, as e.g. altitude, sub-soil, slope, exposition, evapotranspiration, amount, intensity and duration of rainfall, amount of sunshine, humidity, temperature, definability and an only extensive use. Six soils with different ages of fallow land fulfil all the postulated criteria and are dated with the aid of maps, aerial photographs and dendrochonology.

Howald, M.; Schuerch, S.; Schlunegger, U.P. [Univ. of Berne (Switzerland)

1995-12-31

289

Cation Transport in Soils and Factors Affecting Soil Carbonate Solubility.  

Science.gov (United States)

A predictive model of cation transport in soils undergoing miscible displacement was developed and tested. A mass balance equation was formulated to include a general nonlinear cation exchange function. The model was applied to the transport of cations th...

J. J. Jurinak S. H. Lai J. J. Hassett

1973-01-01

290

Predicting hydrocarbon release from soil  

International Nuclear Information System (INIS)

'Full text:' The remediation of hazardous chemicals from soils can be a lengthy and costly process. As a result, recent regulatory initiatives have focused on risk-based corrective action (RBCA) approaches. Such approaches attempt to identify the amount of chemical that can be left at a site with contaminated soil and still be protective of human health and the environment. For hydrocarbons in soils to pose risk to human heath and the environment, the hydrocarbons must be released from the soil and accessible to microorganisms, earthworms, or other higher level organisms. The sorption of hydrocarbons to soil can reduce the availability of the hydrocarbon to receptors. Typically in soils and sediments, there is an initial fast release of a hydrocarbon from the soil to the aqueous phase followed by a slower release of the remaining hydrocarbon to the aqueous phase. The rate and extent of slow release can influence aqueous hydrocarbon concentrations and the fate and transport of hydrocarbons in the subsurface. Once the fast fraction of the chemical has been removed from the soil, the remaining fraction of a chemical may desorb at a rate that natural mechanisms can attenuate the released hydrocarbon. Hence, active remediation may be needed only until the fast fraction has been removed. However, the fast fraction is a soil and chemical specific parameter. This presentation will present a tier I type protocol that has been developed to quickly estimate the fraction of hydrocarbons that are readily released from the soil matrix to the aqueous phase. Previous research in our laboratory and elsewhere has used long-term desorption (four months) studies to determine the readily released fraction. This research shows that a single short-term (less than two weeks) batch extraction procedure provides a good estimate of the fast released fraction derived from long-term experiments. This procedure can be used as a tool to rapidly evaluate the release and bioavailability of hydrocarbons in a contaminated soil. This knowledge can enhance the selection and determine the duration of a proper remediation strategy. Information will be provided on the correlation of the results from this protocol to the results of chemical loss in contaminated soil bioremediation systems. This research has been completed, the data is currently being analyzed and the results will be fully evaluated by early 2002. As a result, the protocol and potential applications to field decisions will be presented and discussed. (author)

2002-01-01

291

SITE-SPECIFIC SOIL QUALITY MANAGEMENT  

Science.gov (United States)

Soil quality is a concept used to assess and monitor the ability of a soil to serve its various functions. This investigation covers four aspects of soil quality with a literature review, and provides complimentary research findings recently conducted on U.S. Midwest claypan soils. The four aspects ...

292

On dynamic soil properties for marine environment  

Energy Technology Data Exchange (ETDEWEB)

Offshore structures are subjected to the action of wind, wave, sea storms, and sea-quakes, and transmit dynamic loads to the underlying soils. This paper highlights the role of dynamic loading on the design soil properties in marine environment. Factors affecting dynamic soil properties and typical soil properties of marine deposits are presented.

Prakash, S.; Kumar, S. [Univ. of Missouri, Rolla, MO (United States)

1994-12-31

293

Communications in Soil Science and Plant Analysis ???????????  

Digital Repository Infrastructure Vision for European Research (DRIVER)

International in coverage, Communications in Soil Science and Plant Analysis presents recent advances in soil science and crop production, with particular reference to elemental content of soils and plants and plant nutrition. Topics include soil chemistry, mineralogy, fertility and testing o...

294

Assessing soil quality in organic agriculture  

Science.gov (United States)

Soil quality is directly linked to food production, food security, and environmental quality (i.e. water quality, global warming, and energy use in food production). Unfortunately, moderate to severe degeneration of soils (i.e., loss of soil biodiversity, poor soil tilth, and unbalanced elemental c...

295

Soils of Walker Branch Watershed  

Energy Technology Data Exchange (ETDEWEB)

The soil survey of Walker Branch Watershed (WBW) utilized the most up-to-date knowledge of soils, geology, and geohydrology in building the soils data base needed to reinterpret past research and to begin new research in the watershed. The soils of WBW were also compared with soils mapped elsewhere along Chestnut Ridge on the Oak Ridge Reservation to (1) establish whether knowledge obtained elsewhere could be used within the watershed, (2) determine whether there were any soils restricted to the watershed, and (3) evaluate geologic formation lateral variability. Soils, surficial geology, and geomorphology were mapped at a scale of 1:1200 using a paper base map having 2-ft contour intervals. Most of the contours seemed to reasonably represent actual landform configurations, except for dense wooded areas. For example, the very large dolines or sinkholes were shown on the contour base map, but numerous smaller ones were not. In addition, small drainageways and gullies were often not shown. These often small but important features were located approximately as soil mapping progressed. WBW is underlain by dolostones of the Knox Group, but only a very small part of the surface area contains outcroppings of rock and most outcrops were located in the lower part. Soil mapping revealed the presence of both ancient alluvium and ancient colluvium deposits, not recognized in previous soil surveys, that have been preserved in high-elevation stable portions of present-day landforms. An erosional geomorphic process of topographic inversion requiring several millions of years within the Pleistocene is necessary to bring about the degree of inversion that is expressed in the watershed. Indeed, some of these ancient alluvial and colluvial remnants may date back into the Tertiary. Also evident in the watershed, and preserved in the broad, nearly level bottoms of dolines, are multiple deposits of silty material either devoid or nearly devoid of coarse fragments. Recent research indicates that most of this silty material is the result of slope wash processed during the Holocene Age. Residual soils of the watershed were related to the underlying geologic formations by their morphology and types of chert. Colluvial soils were identified and mapped whenever the colluvium thickness exceeded 20 in. (50 cm). Except for the ancient colluvial soils (colluvium without a present-day source area), colluvial soils were not separated according to their geologic age, but stacked colluvial deposits are located in low footslope landforms. Colluvial soils in the watershed were identified and mapped according to their morphologic properties that would influence the perching and subsurface movement of water. Alluvial soils were restricted to present floodplains, low fan terraces, and low fan deltas. Nearly all alluvial soils contained very young surficial sediments derived from slopewash resulting from land clearing and subsequent agricultural activities.

Lietzke, D.A.

1994-01-01

296

Soil survey - a basis for european soil protection  

International Nuclear Information System (INIS)

[en] The information available on soils varies greatly from country to country. In view of the fact that, together with water, soils represent the most important natural resource in the EC, it is recommended that steps should be taken to ensure a reasonable level of information for all countries and that emphasis be placed on assembling an adequate database. Such information is fundamental to future land use and environmental protection

1991-01-01

297

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

298

Soils apart from equilibrium consequences for soil carbon balance modelling  

Science.gov (United States)

Many projections of the soil carbon sink or source are based on kinetically defined carbon pool models. Parameters of these models are often determined in a way that the steady state of the model matches observed carbon stocks. The underlying simplifying assumption is that observed carbon stocks are near equilibrium. This assumption is challenged by observations of very old soils that do still accumulate carbon. In this modelling study we explored the consequences of the case where soils are apart from equilibrium. Calculation of equilibrium states of soils that are currently accumulating small amounts of carbon were performed using the Yasso model. It was found that already very small current accumulation rates cause big changes in theoretical equilibrium stocks, which can virtually approach infinity. We conclude that soils that have been disturbed several centuries ago are not in equilibrium but in a transient state because of the slowly ongoing accumulation of the slowest pool. A first consequence is that model calibrations to current carbon stocks that assume equilibrium state, overestimate the decay rate of the slowest pool. A second consequence is that spin-up runs (simulations until equilibrium) overestimate stocks of recently disturbed sites. In order to account for these consequences, we propose a transient correction. This correction prescribes a lower decay rate of the slowest pool and accounts for disturbances in the past by decreasing the spin-up-run predicted stocks to match an independent estimate of current soil carbon stocks. Application of this transient correction at a Central European beech forest site with a typical disturbance history resulted in an additional carbon fixation of 5.7±1.5 tC/ha within 100 years. Carbon storage capacity of forest soils is potentially much higher than currently assumed. Simulations that do not adequately account for the transient state of soil carbon stocks neglect a substantial amount of current carbon accumulation.

Wutzler, T.; Reichstein, M.

2006-10-01

299

Soils apart from equilibrium – consequences for soil carbon balance modelling  

Directory of Open Access Journals (Sweden)

Full Text Available Many projections of the soil carbon sink or source are based on kinetically defined carbon pool models. Para-meters of these models are often determined in a way that the steady state of the model matches observed carbon stocks. The underlying simplifying assumption is that observed carbon stocks are near equilibrium. This assumption is challenged by observations of very old soils that do still accumulate carbon. In this modelling study we explored the consequences of the case where soils are apart from equilibrium. Calculation of equilibrium states of soils that are currently accumulating small amounts of carbon were performed using the Yasso model. It was found that already very small current accumulation rates cause big changes in theoretical equilibrium stocks, which can virtually approach infinity. We conclude that soils that have been disturbed several centuries ago are not in equilibrium but in a transient state because of the slowly ongoing accumulation of the slowest pool. A first consequence is that model calibrations to current carbon stocks that assume equilibrium state, overestimate the decay rate of the slowest pool. A second consequence is that spin-up runs (simulations until equilibrium) overestimate stocks of recently disturbed sites. In order to account for these consequences, we propose a transient correction. This correction prescribes a lower decay rate of the slowest pool and accounts for disturbances in the past by decreasing the spin-up-run predicted stocks to match an independent estimate of current soil carbon stocks. Application of this transient correction at a Central European beech forest site with a typical disturbance history resulted in an additional carbon fixation of 5.7±1.5 tC/ha within 100 years. Carbon storage capacity of disturbed forest soils is potentially much higher than currently assumed. Simulations that do not adequately account for the transient state of soil carbon stocks neglect a considerable amount of current carbon accumulation.

T. Wutzler; M. Reichstein

2007-01-01

300

Soils apart from equilibrium - consequences for soil carbon balance modelling  

Science.gov (United States)

Many projections of the soil carbon sink or source are based on kinetically defined carbon pool models. Parameters of these models are often determined in a way that the steady state of the model matches observed carbon stocks. The underlying simplifying assumption is that observed carbon stocks are near equilibrium. This assumption is challenged by observations of very old soils that do still accumulate carbon. In this modelling study we explored the consequences of the case where soils are apart from equilibrium. Calculation of equilibrium states of soils that are currently accumulating small amounts of carbon were performed using the Yasso model. It was found that already very small current accumulation rates cause big changes in theoretical equilibrium stocks, which can virtually approach infinity. We conclude that soils that have been disturbed several centuries ago are not in equilibrium but in a transient state because of the slowly ongoing accumulation of the slowest pool. A first consequence is that model calibrations to current carbon stocks that assume equilibrium state, overestimate the decay rate of the slowest pool. A second consequence is that spin-up runs (simulations until equilibrium) overestimate stocks of recently disturbed sites. In order to account for these consequences, we propose a transient correction. This correction prescribes a lower decay rate of the slowest pool and accounts for disturbances in the past by decreasing the spin-up-run predicted stocks to match an independent estimate of current soil carbon stocks. Application of this transient correction at a Central European beech forest site with a typical disturbance history resulted in an additional carbon fixation of 5.7±1.5 tC/ha within 100 years. Carbon storage capacity of disturbed forest soils is potentially much higher than currently assumed. Simulations that do not adequately account for the transient state of soil carbon stocks neglect a considerable amount of current carbon accumulation.

Wutzler, T.; Reichstein, M.

2007-02-01

 
 
 
 
301

Soils apart from equilibrium – consequences for soil carbon balance modelling  

Directory of Open Access Journals (Sweden)

Full Text Available Many projections of the soil carbon sink or source are based on kinetically defined carbon pool models. Parameters of these models are often determined in a way that the steady state of the model matches observed carbon stocks. The underlying simplifying assumption is that observed carbon stocks are near equilibrium. This assumption is challenged by observations of very old soils that do still accumulate carbon. In this modelling study we explored the consequences of the case where soils are apart from equilibrium. Calculation of equilibrium states of soils that are currently accumulating small amounts of carbon were performed using the Yasso model. It was found that already very small current accumulation rates cause big changes in theoretical equilibrium stocks, which can virtually approach infinity. We conclude that soils that have been disturbed several centuries ago are not in equilibrium but in a transient state because of the slowly ongoing accumulation of the slowest pool. A first consequence is that model calibrations to current carbon stocks that assume equilibrium state, overestimate the decay rate of the slowest pool. A second consequence is that spin-up runs (simulations until equilibrium) overestimate stocks of recently disturbed sites. In order to account for these consequences, we propose a transient correction. This correction prescribes a lower decay rate of the slowest pool and accounts for disturbances in the past by decreasing the spin-up-run predicted stocks to match an independent estimate of current soil carbon stocks. Application of this transient correction at a Central European beech forest site with a typical disturbance history resulted in an additional carbon fixation of 5.7±1.5 tC/ha within 100 years. Carbon storage capacity of forest soils is potentially much higher than currently assumed. Simulations that do not adequately account for the transient state of soil carbon stocks neglect a substantial amount of current carbon accumulation.

T. Wutzler; M. Reichstein

2006-01-01

302

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

303

Refining soil survey information for a Dutch soil series using land use history  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Differences in land-use history within soil series, although not influencing soil classification, lead to variability of non-diagnostic soil properties in soil databases. Regional studies that use soil databases are confronted with this considerable variability. This has, for example, been reported ...

Sonneveld, M.P.W.; Bouma, J.; Veldkamp, A.

304

SOIL REDOX AND PH EFFECTS ON METHANE PRODUCTION IN A FLOODED RICE SOIL  

Science.gov (United States)

Methane formation in soil is a microbiological process controlled by many factors. f them soil redox potential (Eh) and soil pH are considered as critical controls. aboratory incubation experiment was conducted to study the critical initiation soil Eh, the optimum soil pH and the...

305

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.

H.A. Torbert; E. Krueger; D. Kurtener

2008-01-01

306

Interactions of halogenated hydrocarbons with soils  

Energy Technology Data Exchange (ETDEWEB)

The most important interactions of halogenated hydrocarbons (HHCs) with soils are sorption processes. A method is presented to determine sorption equilibria of volatile HHCs with soils. Results of the HHCs investigated (three aliphatic, five aromatic) confirm that the sorptive capacities of soils are mainly influenced by their contents in soil organic matter. Mineral soil components adsorb very little. Sorptive processes are highly reversible. Comparison of the sorption constants of the different compounds show that their solubilities strongly influence the sorptive behaviour in soils. There is evidence that a theoretical approach to sorption processes in soils must incorporate further compound parameters related to molecule structure.

Friesel, P.; Milde, G.; Steiner, B.

1984-09-01

307

National Soil DataBase (NSDB)  

Science.gov (United States)

The Canadian Soil Information System (CanSIS) hosts the National Soil DataBase (NSDB), a set of data files including soil, landscape, and climatic variables for all of Canada. The NSDB includes GIS coverages for several scales, in addition to listing characteristics for each soil series. Principle data holdings include National Ecological Framework (EcoZones, EcoRegions, and EcoDistricts); Soil Map of Canada/ Land Potential DataBase (LPDB); Agroecological Resource Areas (ARAs); Soil Landscapes of Canada (SLC); Canada Land Inventory (CLI); and Detailed Soil Surveys. Most datasets are available for free at the Website; files are in ARC/INFO Export format only.

2008-08-08

308

Allowable soil erosion rates in Georgia  

Science.gov (United States)

A procedure was proposed for the determination of the maximum allowable soil disturbance in Georgia in order to develop a strategy of soil conservation and restoration. The allowable soil losses were calculated within the risk limits of 0.01 < r < 0.1. The lower and upper limits of the allowable soil loss were determined for the soils of different thicknesses. To compare the rates of the soil erosion, one uses the erosion index: the ratio between the actual erosion rate and its maximum allowable value. The actual erosion rate is determined from erosion equations, in which the integrated parameters of the soil loss tolerance include the permissible flow velocity and data on the climatic and soil conditions. From the estimated allowable soil erosion rates, criteria of decision making can be formulated for substantiating the strategy of soil conservation or restoration.

Kereselidze, D. N.; Matchavariani, L. G.; Kalandadze, B. B.; Trapaidze, V. Z.

2013-04-01

309

Soil physics meets soil biology: Towards better mechanistic prediction of greenhouse gas emissions from soil  

UK PubMed Central (United Kingdom)

One of the issues hampering progress in modelling greenhouse gas (GHG) emissions from soils is a lack of co-ordination between models originating from different disciplines: soil physics and soil biology. We have reviewed recent advances in modelling both gaseous transport and the biochemical processes in the soil that lead to the emission of the main biogeneic GHGs: CO2, N2O, and CH4. The precise coupling of gaseous transport and biochemistry is necessary because CH4 and N2O can be both produced and consumed in soil, and eventual flux to the atmosphere depends on the position of reaction sites and the escape pathways for these gases. The CO2 production rate depends in turn on the efficiency of oxygen transport in the soil. Principles leading to successful simulation are: keeping a balanced level of detail in coupled model systems describing biochemical reactions and transport; reduction of unnecessary complexity by means of using the most essential relationships elucidated by comprehensive statistical model testing; consideration of all transport mechanisms in relation to prevailing ecological conditions, i.e., diffusion and convection in the air and liquid phases, plant-mediated transport and ebullition. It is important to model all three major GHG in accord with the description of O2 and N2 transport and concentration in soil. This helps: i) to estimate the full global warming potential; ii) to apply the model algorithms considering partial gas pressure and gas species interactions; iii) to describe the O2 effect on the biochemical processes in soil. We discuss the approaches linking the simple and more complex process-oriented models, and propose a strategy for up-scaling model results from soil aggregate to profile and to the field/catchment.

Blagodatsky S; Smith P

2012-04-01

310

Radionuclide migration studies in soil  

International Nuclear Information System (INIS)

In this work a brief description about retention and migration parameters of radionuclides in soil, including main methods to determine the distribution coefficient (K) are given. Some of several factors that can act on the migration are also mentioned. (author).

1989-01-01

311

Phytoremediation of Soil Trace Elements  

Science.gov (United States)

Phytoremediation includes several distinct approaches to using plants to achieve soil remediation goals. Phytoextraction uses rare hyperaccumulator plants to accumulate in their shoots enough metals per year to achieve decontamination goals. Phytomining uses hyperaccumulators and biomass burn to pro...

312

Soil mechanics concepts and applications  

CERN Multimedia

The aim of this book is to encourage students to develop an understanding of the fundamentals of soil mechanics. It builds a robust and adaptable framework of ideas to support and accommodate the more complex problems and analytical procedures that

Powrie, William

2004-01-01

313

Modelling refractory soil organic matter.  

UK PubMed Central (United Kingdom)

Most models for the turnover of soil organic matter (SOM) include a compartment that is either considered insert, or has a very slow turnover time (refractory SOM; RSOM). The RSOM content of soils varies markedly between sites, and knowledge of its size and variability are essential for determining whether soils behave as sources or sinks of atmospheric CO2. It has also have been suggested that the accurate specification of RSOM pools is essential to modelling studies, and that uncertainty in estimates of the size of RSOM pool could be a major source of error in modelling soil organic C. In this paper, current SOM models are reviewed, and approaches to modelling RSOM and its significance are discussed. Simulations of SOM turnover for the Rothamsted Broadbalk winter wheat experiment using the Rothamsted C model and CENTURY are presented as examples.

Falloon PD; Smith P

2000-01-01

314

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.

Valery P. Kalinichenko; Murad M. Kodzoev; Ahmed M. Tochiev; Beslan B. Mamilov; Mohammed A. Bazgiev

2012-01-01

315

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

2011-01-01

316

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

317

Structure and composition of soils  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents a study of soils structure and composition using up to date technique, such as scanning electronic microscopy, atomic force microscopy, X-ray diffraction, X-ray fluorescence, as well as some other characterization methods. It was shown that soil particles have porous structure and dimensions in the range from several millimeters to several hundreds of nanometers and consist of different minerals such as kaolin, quartz and feldspate.

Snežana Nenadovi?; Miloš Nenadovi?; Ljiljana Kljajevi?; Vladimir Pavlovi?; Aleksandar ?or?evi?; Branko Matovi?

2010-01-01

318

Predicting soil respiration from peatlands.  

UK PubMed Central (United Kingdom)

This study considers the relative performance of six different models to predict soil respiration from upland peat. Predicting soil respiration is important for global carbon budgets and gap filling measured data from eddy covariance and closed chamber measurements. Further to models previously published new models are presented using two sub-soil zones and season. Models are tested using data from the Bleaklow plateau, southern Pennines, UK. Presented literature models include ANOVA using logged environmental data, the Arrhenius equation, modified versions of the Arrhenius equation to include soil respiration activation energy and water table depth. New models are proposed including the introduction of two soil zones in the peat profile, and season. The first new model proposes a zone of high CO(2) productivity related to increased soil microbial CO(2) production due to the supply of labile carbon from plant root exudates and root respiration. The second zone is a deeper zone where CO(2) production is lower with less labile carbon. A final model allows the zone of high CO(2) production to become dormant during winter months when plants will senesce and will vary depending upon vegetation type within a fixed location. The final model accounted for, on average, 31.9% of variance in net ecosystem respiration within 11 different restoration sites whilst, using the same data set, the best fitting literature equation only accounted for 18.7% of the total variance. Our results demonstrate that soil respiration models can be improved by explicitly accounting for seasonality and the vertically stratified nature of soil processes. These improved models provide an enhanced basis for calculating the peatland carbon budgets which are essential in understanding the role of peatlands in the global C cycle.

Rowson JG; Worrall F; Evans MG; Dixon SD

2013-01-01

319

Predicting soil respiration from peatlands.  

Science.gov (United States)

This study considers the relative performance of six different models to predict soil respiration from upland peat. Predicting soil respiration is important for global carbon budgets and gap filling measured data from eddy covariance and closed chamber measurements. Further to models previously published new models are presented using two sub-soil zones and season. Models are tested using data from the Bleaklow plateau, southern Pennines, UK. Presented literature models include ANOVA using logged environmental data, the Arrhenius equation, modified versions of the Arrhenius equation to include soil respiration activation energy and water table depth. New models are proposed including the introduction of two soil zones in the peat profile, and season. The first new model proposes a zone of high CO(2) productivity related to increased soil microbial CO(2) production due to the supply of labile carbon from plant root exudates and root respiration. The second zone is a deeper zone where CO(2) production is lower with less labile carbon. A final model allows the zone of high CO(2) production to become dormant during winter months when plants will senesce and will vary depending upon vegetation type within a fixed location. The final model accounted for, on average, 31.9% of variance in net ecosystem respiration within 11 different restoration sites whilst, using the same data set, the best fitting literature equation only accounted for 18.7% of the total variance. Our results demonstrate that soil respiration models can be improved by explicitly accounting for seasonality and the vertically stratified nature of soil processes. These improved models provide an enhanced basis for calculating the peatland carbon budgets which are essential in understanding the role of peatlands in the global C cycle. PMID:23178842

Rowson, J G; Worrall, F; Evans, M G; Dixon, S D

2012-11-22

320

Testing oils in antarctic soils  

International Nuclear Information System (INIS)

The resident seals, whales and penguins in Antarctica's Ross Sea region have only environmentally friendly ways of getting around. In contrast, wherever humans go in the Antarctic and whatever they do, be it research, tourism or fishing, they need fuel for their planes, icebreaker ships, land vehicles and generators. Because of this, petroleum hydrocarbons are the most likely source of pollution in the Antarctic. Accidental oil spills often occur near scientific stations, where storage and refuelling of aircraft and vehicles can result in spills. Spills also occur as a consequence of drilling activities. Dr Jackie Aislabie, a microbiologist from the New Zealand government's research company Landcare Research, is leading a program aimed at understanding how oil spills impact on Antarctic soils. The properties of pristine soils were compared with oil-contaminated soil at three locations: Scott Base, Marble Point and in the Wright Valley at Bull Pass. Soils in the Scott Base area are impacted by the establishment and continuous habitation of the base over 40 years, and a hydrocarbon-contaminated site was sampled near a former storage area for drums of mixed oils. Soil sampled from Marble Point was taken from near the old Marble Point camp, which was inhabited from 1957 to about 1963. Oil stains were visible on the soil surface, and are assumed to have been there for more than 30 years. The samples selected for analysis from the Wright Valley came from a spill site near Bull Pass that occurred during seismic bore-hole drilling activities in 1985. The contamination levels ranged from below detection to just over 29,000 ?g/g of soil. Descriptions and analyse results are included into a Geographic Information System and associated soils database

 
 
 
 
321

Using nematodes in soil ecotoxicology.  

Science.gov (United States)

Nematodes represent a very abundant group of soil organisms and non-parasitic species are important for soil quality and in the soil food web. In recent years, it has been shown that nematodes are appropriate bioindicators of soil condition and they are also suitable organisms for laboratory toxicity testing. The aims of this paper are to overview and critically assess methods and approaches for researching soil nematode ecotoxicology. In natural ecosystems, nematode abundance and community structure analyses were proved to be sensitive indicators of stress caused by soil pollutants and ecological disturbance. Community structure analyses may be approached from a functional or ecological point of view; species are divided into groups according to their feeding habits or alternatively the maturity index is calculated according to their ecological strategy. Many environmental factors have the potential to affect nematode community, which consequently results in high space and time variability. This variance is major handicap in field ecotoxicological studies because pollutant-nematode relationships are obscured. For prospective risk assessment of chemicals, several toxicity tests with nematodes were developed and are increasingly used. Sensitivity of these tests is comparable to tests with other soil species (e.g. enchytraeids, earthworms and springtails) while tests are less demanding to space and time. Most studies have focused on metal toxicity but organic compounds are almost overlooked. Endpoints used in tests were often mortality, reproduction or movement, but more sublethal endpoints such as feeding or biomarkers have been used recently too. Although there is an increasing amount of knowledge in soil nematode ecotoxicology, there is still a lot of various issues in this topic to research. PMID:16213020

Sochová, Ivana; Hofman, Jakub; Holoubek, Ivan

2005-10-05

322

European soil sampling guidelines for soil pollution studies.  

UK PubMed Central (United Kingdom)

The soil sampling guidelines used in European countries (ESSG), as kindly provided by the national institutions which participated in the project, have been recorded, studied, evaluated and presented in this paper. The aim has been to ascertain what soil sampling guidelines exist in Europe; to detect similarities and differences (comparable results), advantages and deficiencies; to identify incompatible strategies and evaluate how methodologies might affect data quality; to investigate sources of deviations or uncertainties; to improve comparability and representativeness of soil sampling; to investigate the need for harmonised sampling guidelines; and to develop suggestions for standard operating procedures (SOP). Soil sampling guidelines throughout Europe differ as to whether they are applied by law, or used throughout the country. In some countries these are ISO/DIS related or based (ISO 10381-1, 1995; ISO 10381-2, 1995), or are produced by a scientific society or a standardisation body. As far as sampling strategy is concerned, not all sampling guidelines clearly describe the sampling scale, the specifications for contamination risk precautions, the sampling plan and protocol structure and the pre-analysis treatment of the soil samples. The purpose for sampling, in descending order of frequency, is soil pollution, soil fertilisation, general soil monitoring, background risk assessment, or else it is not specified. The majority of countries do not sample the top organic matter separately. Sampling depth is either related to the morphogenetic horizon or to ad hoc sampling depth, which is not specified in all cases. They suggest mass- and volume-related soil sampling, while the sampling pattern is not presented in all national guidelines. The criteria for area, site, unit, sub-unit, and point selection are mainly based on pedology and land use, following the history and pre-screening information or geology, or is site related. Some guidelines suggest the division of sampling units into sub-units. The sampling pattern is mainly grid sampling, grid and random sampling, or not mentioned. Sampling density inside the sampling unit either varies greatly or it is not mentioned, while the size of the sampling unit varies widely. Most guidelines require the collection of composite instead of simple samples, while some prefer sampling soil profiles. In the European SSG many technical details and steps are either not defined or vary, while in the pre-analysis treatment quality assurance (QA) and quality control (QC) approaches are used either both in the lab and in the field, or only in the field, or are not mentioned. The common points and the points in which harmonisation could be started or achieved are discussed.

Theocharopoulos SP; Wagner G; Sprengart J; Mohr ME; Desaules A; Muntau H; Christou M; Quevauviller P

2001-01-01

323

Factors affecting triadimefon degradation in soils.  

UK PubMed Central (United Kingdom)

The degradation of triadimefon [1-(4-chlorophenoxy)-3,3-dimethyl-1-(1H-1,2,4-triazol-1-yl)butan-2-one] was studied in two soils, mollisol and inseptisol, under varying conditions of moisture and temperature, and the role of cow manure amendment and soil sterilization on fungicide degradation was ascertained. The soil moisture content affected the pathway followed for triadimefon degradation. In nonflooded soils (60% water-holding capacity), triadimefon was reduced to triadimenol, and in flooded soils, it was metabolized to the diol derivative [1-(1H-1,2,4-triazol-1-yl)-3,3-dimethylbutan-2-one-1,4-diol]. In nonflooded soils, triadimefon was more persistent in soil having more organic carbon content (mollisol), and the amendment of cow manure (5%) further enhanced its persistence. On the contrary, in flooded soil systems, the higher the soil organic carbon content was, the less persistent was the fungicide, and amendment of cow manure further enhanced its degradation. Triadimefon degradation was faster at 35 degrees C than at 27 degrees C. Triadimefon degradation in soils was mediated by the microorganisms, and no triadimefon degradation was observed in sterile soils. Triadimefon (1 mg/kg) did not affect soil phosphatase activity in either of the soils; however, soil dehydrogenase activity was significantly reduced, especially in mollisol soil.

Singh N

2005-01-01

324

METHOD FOR RESTORING SOIL FERTILITY  

UK PubMed Central (United Kingdom)

FIELD: agriculture, soil science. SUBSTANCE: the present innovation deals with restoring fertility of low productive arable farming lands, oil-contaminated lands and erosiondangerous slopes. The suggested method deals with soil loosening, presowing rolling, sowing agricultural varieties, postsowing rolling. Primary soil treatment should be carried out in autumn due to shallow plowing, in spring it is necessary to apply NPK fertilizers, their dosage is calculated by removal of nutrients by the yield, so, the ground should be cultivated, rolled to perform sowing of phytomeliorant varieties, such as sweet clover, rape, winter cress, mustard, oil radish, moreover, plants with biennial cycle should be sown under annual grasses' cover followed by rolling. Green mass of phytomeliorants should be applied as green manure fertilizer. Mineral fertilizers such as nitrogen, phosphorus and potassium are applied for planned yield in spring under cultivation by taking into account the content of these nutrients in soil. The present method enables to restore fertility of low-productive soils, erosion-dangerous parts and oil-contaminated soils. EFFECT: higher efficiency of restoration. 2 ex, 4 tbl

SATUBALDIN K K; SALANGINAS L A

325

Brazilian Cerrado Soil Actinobacteria Ecology  

Science.gov (United States)

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 (rainy and dry). The rainy season produced a high microbial population of all the aforementioned genera. The pH values of the soil samples from the Passos, Luminárias, and Arcos regions varied from 4.1 to 5.5. There were no significant differences in the concentrations of phosphorus, magnesium, and organic matter in the soils among the studied areas. Samples from the Arcos area contained large amounts of aluminium in the rainy season and both hydrogen and aluminium in the rainy and dry seasons. The Actinobacteria population seemed to be unaffected by the high levels of aluminium in the soil. Studies are being conducted to produce bioactive compounds from Actinobacteria fermentations on different substrates. The present data suggest that the number and diversity of Actinobacteria spp. in tropical soils represent a vast unexplored resource for the biotechnology of bioactives production.

Suela Silva, Monique; Naves Sales, Alenir; Teixeira Magalhaes-Guedes, Karina; Ribeiro Dias, Disney; Schwan, Rosane Freitas

2013-01-01

326

Brazilian Cerrado soil Actinobacteria ecology.  

UK PubMed Central (United Kingdom)

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 (rainy and dry). The rainy season produced a high microbial population of all the aforementioned genera. The pH values of the soil samples from the Passos, Luminárias, and Arcos regions varied from 4.1 to 5.5. There were no significant differences in the concentrations of phosphorus, magnesium, and organic matter in the soils among the studied areas. Samples from the Arcos area contained large amounts of aluminium in the rainy season and both hydrogen and aluminium in the rainy and dry seasons. The Actinobacteria population seemed to be unaffected by the high levels of aluminium in the soil. Studies are being conducted to produce bioactive compounds from Actinobacteria fermentations on different substrates. The present data suggest that the number and diversity of Actinobacteria spp. in tropical soils represent a vast unexplored resource for the biotechnology of bioactives production.

Suela Silva M; Naves Sales A; Teixeira Magalhães-Guedes K; Ribeiro Dias D; Schwan RF

2013-01-01

327

Denitrification in suburban lawn soils.  

UK PubMed Central (United Kingdom)

There is great uncertainty about the fate of nitrogen (N) added to urban and suburban lawns. We used direct flux and in situ chamber methods to measure N and NO fluxes from lawns instrumented with soil O sensors. We hypothesized that soil O, moisture, and available NO were the most important controls on denitrification and that N and NO fluxes would be high following fertilizer addition and precipitation events. While our results support these hypotheses, the thresholds of soil O, moisture, and NO availability required to see significant N fluxes were greater than expected. Denitrification rates were high in saturated, fertilized soils, but low under all other conditions. Annual denitrification was calculated to be 14.0 ± 3.6 kg N ha yr, with 5% of the growing season accounting for >80% of the annual activity. Denitrification is thus an important means of removing reactive N in residential landscapes, but varies markedly in space, time, and with factors that affect soil saturation (texture, structure, compaction) and NO availability (fertilization). Rates of in situ NO flux were low; however, when recently fertilized soils saturated with water were incubated in the laboratory, we saw extraordinarily high rates of NO production for the first few hours of incubation, followed by rapid NO consumption later in the experiment. These findings indicate a lag time between accelerated NO production and counterbalancing increases in NO consumption; thus, we cannot yet conclude that lawns are an insignificant source of NO in our study area.

Raciti SM; Burgin AJ; Groffman PM; Lewis DN; Fahey TJ

2011-11-01

328

Bioremediation of contaminated surface soils  

Energy Technology Data Exchange (ETDEWEB)

Biological processes, including microbial degradation, have been identified as critical mechanisms for attenuating organic contaminants during transit through the vadose zone to the groundwater. On-site soil remedial measures using biological processes can reduce or eliminate groundwater contamination, thus reducing the need for extensive groundwater monitoring and treatment requirements. On-site remedial systems that utilize the soil as the treatment system accomplish treatment by using naturally occurring microorganisms to treat the contaminants. Treatment often may be enhanced by a variety of physical/chemical methods, such as fertilization, tilling, soil pH adjustment, moisture control, etc. The development of a bioremediation program for a specific contaminated soil system includes: (1) a thorough site/soil/waste characterization; (2) treatability studies; and (3) design and implementation of the bioremediation plan. Biological remediation of soils contaminated with organic chemicals has been demonstrated to be an alternative treatment technology that can often meet the goal of achieving a permanent clean-up remedy at hazardous waste sites.

Sims, J.L.; Sims, R.C.; Matthews, J.E.

1989-08-01

329

Electrokinetic remediation of contaminated soils  

Energy Technology Data Exchange (ETDEWEB)

Electrokinetic remediation of contaminated soil has been demonstrated for saturated and unsaturated sand in preliminary experiments using a novel transport visualization technique. Large anionic organic dyes were mixed with a portion of soil and the rate of electromigration of the dye in an imposed electric field was monitored photographically. One of the fastest current-normalized electromigration rates was measured in the driest sand, which contained 7% water by weight. This moisture content is typical of the moisture content in the unsaturated zone of subsurface native soils found in New Mexico. The characteristics of the electromigration were similar in both the saturated and unsaturated sand. The leading edge of the dye migration front was diffuse while the trailing edge was sharp and concentrated. This and other observed behavior may indicate a concentration effect, where the electromigration rate of dilute dye is greater than that of concentrated dye. The soil left after the trailing edge passed seemed to contain no residual dye in both the saturated and unsaturated cases. The success of demonstrating electromigration of large molecules in unsaturated soil is encouraging and indicates that it may be feasible to remediate in situ anionic heavy metals such as chromate from unsaturated soil with electrokinetic techniques. 23 refs., 7 figs.

Lindgren, E.R.; Kozak, M.W. (Sandia National Labs., Albuquerque, NM (United States)); Mattson, E.D. (SAT-UNSAT, Inc., Albuquerque, NM (United States))

1991-01-01

330

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; Cc.X Sun; L.J Chen; Z.H Duan

2009-01-01

331

SOIL BULK DENSITY AS RELATED TO SOIL PARTICLE SIZE DISTRIBUTION AND ORGANIC MATTER CONTENT  

Directory of Open Access Journals (Sweden)

Full Text Available Soil bulk density is a dynamic property that varies with the soil structural conditions. The relationships between some soil physical and chemical properties such as, clay content (C), silt content (Si), sand content (S), very fine sand content (Vfs) and organic matter content (OMC) with soil bulk density (?b) were studied using path analysis on 77 surface soil samples (0-20 cm). Soil bulk density showed positive relationships with S and Vfs and negative relationships with Si, C and OMC. It was determined that the direct effects of some soil properties on ?bwere in the following order; S>C>Si>OMC>Vfs. On the other hand, the indirect effects of soil particle size distribution varied among soil bulk densities. The indirect effects of the soil particle size distribution generally occured through sand content. Sand content was the most effective soil property that affected bulk density in soils.

Tayfun A?kin; Natullah Özdemir

2003-01-01

332

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

2004-01-01

333

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

Science.gov (United States)

Anaerobic N mineralization measured from (saturated) repacked soil cores from 25 paddy fields in Bangladesh and was previously found to negatively related to soil N content on a relative basis. This suggests that other factors like soil organic matter (SOM) quality or abiotic factors instead control the anaerobic N mineralization process. We therefore assessed different physical and chemical fractions of SOM, management factors and various soil properties as predictors for the net anaerobic N mineralization. 1° First, we assessed routinely analyzed soil parameters (soil N and soil organic carbon, texture, pH, oxalate- and pyrophosphate-extractable Fe, Al, and Mn, fixed-NH4 content). We found no significant influences of neither soil mineralogy nor the annual length of inundation on soil N mineralization. The anaerobic N mineralization correlated positively with Na-pyrophosphate-extractable Fe and negatively with pH (both at Predox potential, Fe in solution and mineral N.

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

2013-04-01

334

SOIL CULTIVATION TOOL DEVICE  

UK PubMed Central (United Kingdom)

The invention relates to a hand tool or power tool device for cultivating the ground and soil, such as a hoe or hoeing tool, scraper, or the like, essentially comprising a working tool that is releasably or permanently mounted at the front end of a handle or the like which optionally has one or more specific holding zones or grips. The working tool is essentially composed of a bent integral or welded multipart metal strip to form a U-shaped lower section (6), at least part of which is used for cutting, and a shaped upper section to be mounted at the front end (3') of the handle (3). The strip section extends between the legs of the U-shaped section (6), forms the core of the U, and has a serrated profile including teeth on the opposite longitudinal edges thereof, said teeth being preferably staggered. The device (1) is characterized in that said strip section is sharp at the two opposite longitudinal edges thereof.

PELLENC ROGER

335

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; Joseph G. Benjamin; Ardell D. Halvorson; David C. Nielsen

2013-01-01

336

Phytoremediation potential of Brassica juncea in Cu-pyrene co-contaminated soil: Comparing freshly spiked soil with aged soil.  

UK PubMed Central (United Kingdom)

A comparison was made between the dissipation of pyrene as well as the uptake of copper (Cu) in soil freshly spiked with Cu, pyrene or Cu + pyrene and in aged soil. The potential of B juncea for phytoremediation was also investigated. The biomass of Brassica juncea significantly decreased (>50% reduction) in freshly spiked soil when compared to aged soil in all treatments. However, the accumulation of Cu in shoot was significantly reduced (60-88%) in aged soil after 60 days of planting. The total removal of Cu from co-contaminated soil was always higher (>2-3 fold) in aged soil than in freshly spiked soil when lower Cu concentration (50 mg kg(-1)) was co-contaminated with 250 or 500 mg kg(-1) of pyrene while in other co-contaminated treatments, the total removal of Cu from aged soil were significantly lower. The level of pyrene in both planted and un-planted freshly spiked soil decreased significantly (>67%) over the 60 days of plant trial. In aged soils, there were no significant differences in residual pyrene concentration between planted and unplanted soil. This suggests that the presence of B. juncea in aged soil did not enhance the dissipation of pyrene and that the prediction of pyrene dissipation in laboratory prepared soil may not have reflected the true situation in the fields.

Chigbo C; Batty L

2013-06-01

337

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

Energy Technology Data Exchange (ETDEWEB)

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.

Toufigh, M.M.

1987-01-01

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; A. A. Mahboubi; M. R. Mosaddeghi; A. Safadoust

2012-01-01

339

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

International Nuclear Information System (INIS)

Much effort has been focused on defining the end-point of bioremediated soils by chemical analysis (Alberta Tier 1 or CCME Guideline for Contaminated Soils) or toxicity tests. However, these tests do not completely assess the soil quality, or the capability of soil to support plant growth after bioremediation. This study compared barley (Hordeum vulgare) growth on: (i) non-contaminated, agricultural topsoil, (2) oil-contaminated soil (4% total extractable hydrocarbons, or TEH), and (3) oil-contaminated soil treated by bioremediation (

1995-01-01

340

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

Scientific Electronic Library Online (English)

Full Text Available 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 regre (more) ssion 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

2013-02-01

 
 
 
 
341

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; Jozef Vil?ek

2011-01-01

342

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

343

Long-term Impact of Rotary Method of Soil Mechanical Treatment on Soil Properties  

Directory of Open Access Journals (Sweden)

Full Text Available The imitating approach to the technique and technology of soil cultivation excels the influence of natural factors of soil formation and leads to the anthropogenic biosphere degradation. The article fundamentally justifies the rotary soil cultivation in terms of genesis of soil. This method provides the formation of a new layer in the soil depth, which intensifies the geological and biological processes, influences the overlying soil layers, increases the biological productivity of the soil and stability of its mechanical system for a long term. Technical solutions of rotary devices for soil cultivation are considered and long-term results of their practical application are presented.

Valeriy P. Kalinichenko; Vladimir K. Sharshak; Vladimir E. Zinchenko; Ali A. Zarmaev; Evgeny P. Ladan; Vladimir V. Chernenko; L’udmila P. Il’ina

2012-01-01

344

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; Gustavo Di Chiacchio Faulin

2013-01-01

345

Soil microbiology in land reclamation volume I - soil microbial development  

Energy Technology Data Exchange (ETDEWEB)

This volume contains two separate reports: RRTAC 84-5 (Reinstatement of biological activity in severely disturbed soils: effects of mining on the microbiology of three mine spoils and the microbiological development in the minespoils after amendation and planting); RRTAC 84-6 (Reinstatement of biological activity in severely disturbed soils: effects of different amendments to three different minespoils on selected soil physical and chemical properties and plant growth). This first report covers a project to determine the immediate effects of coal and bitumen mining on a variety of soil microbiological factors and to provide detailed information on the rates of redevelopment of biological activity when various organic and inorganic amendments are applied singly to various minespoils and subsequently planted with different herbaceous and woody plant species. The second project reports on three minespoils (prairie grassland, subalpine and extracted oil sands) treated with three different organic or inorganic amendments and then planted with four different plant species. Amendment effects on some of the soil chemical characteristics and plant growth were monitored over 2 and 3 years respectively.

Graves, D.H. (ed.)

1984-01-01

346

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

347

Soil compaction and growth of woody plants  

Energy Technology Data Exchange (ETDEWEB)

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.

Kozlowski, T.T. [Univ. of California, Berkeley (United States). Dept. of Environmental Science, Policy and Management

1999-07-01

348

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

349

Stocks of organic carbon in Estonian soils  

Directory of Open Access Journals (Sweden)

Full Text Available 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 ± 36.9 Tg of SOC is retained, with 64.9% (385.3 ± 27.5 Tg) in the epipedon layer (O, H, and A horizons) and 35.1% in the subsoil (B and E horizons). The pedo-ecological regularities of SOC retention in soils are analysed against the background of the Estonian soil ordination net.

Kõlli, Raimo; Ellermäe, Olav; Köster, Tiia; Lemetti, Illar; Asi, Endla; Kauer, Karin

2009-01-01

350

Interaction between soil formation and landslide occurrence  

Science.gov (United States)

Many different models exist for landslide prediction. Possibly the parameter with the highest uncertainty in these models is soil depth. While most studies acknowledge its importance, few studies include spatial variability of soil depth in the predictions. In addition, in mountainous areas landslides are one of the main processes shaping the relief and therefore have a significant impact on the spatial distribution of soils. In this study, we model the interaction between long-term soil formation and landsliding. Soil formation from bedrock is modeled by a depth-dependent soil production function. Soil is then redistributed in the landscapes by water erosion processes and landslides. Factor of safety is calculated at each time step by using the dynamic soil thickness and rainfall. First, the model is evaluated by comparison of modeled soil depth with published field measurements (Iida et al., 1999). The relation between soil depth and topographical attributes, such as slope, curvature or compound topographic index show how including landsliding processes generates patterns of soil depth that reflect much better the observations than a simple model that only includes soil formation and water erosion. Finally, the model is applied to a study area in the Akaishi Mountains to model the occurrence of landslides in that area. Landslides were mapped by remote sensing between 1992-2002. It is shown how by taking into account the modeled soil depths, the prediction of landslide occurrence is improved over a model with spatially constant soil depth.

Vanwalleghem, Tom; Saito, Hitoshi; Hayakawa, Yuichi; Oguchi, Takashi

2013-04-01

351

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).

2001-01-01

352

pH in Swedish forest soils  

Energy Technology Data Exchange (ETDEWEB)

A survey of forest site conditions has been carried out in collaboration with the National Forest Survey in Sweden. The survey has been done as an annual strip mapping of the productive forest area in Sweden. In this investigation the relationships between pH in the humuslayers (A/sub 0/) and other site factors are given in 20 coloured maps and based upon soil analysis from 27 000 sample plots. Some of the site properties are soil type, soil genesis, soil depth soil horizons, soil moisture, tree species, the age of the tree stand etc.

Troedsson, T.; Nilsson, Aa.

1984-07-01

353

Phytoremediation of carbofuran residues in soil  

Directory of Open Access Journals (Sweden)

Full Text Available In this study, the ability of plants to clean up carbofuran residues in rice field soil was examined. Plants were grown in 8 inches diameter plastic pots filled with soils containing 5 mg/kg carbofuran. Phytoremediated samples were analyzed for carbofuran concentration. The results showed that carbofuran was rapidly degraded under planted soil and non-planted soil with half-lives ranging from 2-7 days. These facts suggest that phytoremediation could accelerate the degradation of carbofuran residues in soil and carbofuran was not persistent in the soil environment.

Mullika Teerakun; Alissara Reungsang; Wanpen Virojanakud

2004-01-01

354

Cs-137 migration in soil near NPPs  

International Nuclear Information System (INIS)

A convective-diffusion model has been employed for describing Cs-137 migration in soil. The migration parameters were determined by comparing the calculated vertical distribution profiles with the experimental ones. The migration parameters dependence on the soil state has been studied. Cs-137 penetration rate was found to be function of the soil type, surface state, soil wetness and orography. The obtained values are presented. A method is suggested for revealing the soil surface contamination by Cs-137 produced during NPP operation with distinguishing it from the global contamination background. For this purpose Cs-137 content in the upper 5 mm soil layer is estimated

1984-01-01

355

Biodegradation of PCP in soil  

Energy Technology Data Exchange (ETDEWEB)

Survival and activity of the pentachlorophenol (PCP)-mineralizer Mycobacterium chlorophenolicum after inoculation into a natural soil were studied at bench and field scales. The PCP-concentration was 30 mg kg{sup {minus}1} soil. Inoculation levels were 10{sup 6} to 10{sup 9} cells g{sup {minus}1} soil. The effect of immobilization in the inocula on polyurethane foam (PUF) was investigated at bench scale. PCP-mineralization was measured using {sup 14}C-PCP at bench scale and by soil chemical analyses in the field. The population dynamics of the degrader were followed by immunofluorescence microscopy using specific immunoprobes. It was shown that M. chlorophenolicum was still present at 1 order of magnitude below inoculation level with both immobilized and nonimmobilized cells after up to 1 year. However, inoculation at 10{sup 8} and 10{sup 6} cells g{sup {minus}1} soil did not raise the PCP-mineralization rate over the background level when cells had not been immobilized. Inoculation with PUF-immobilized cells significantly stimulated the rate of biodegradation at bench and field scales. Formation of chloroanisols or chloroveratroles through biomethylation of chlorophenols was observed upon inoculation with nonimmobilized cells at field scale.

Karlson, U.; Miethling, R.; Schu, K. [National Environmental Research Inst., Roskilde (Denmark); Hansen, S.S. [A/S Bioteknisk Jordrens, Kalundborg (Denmark); Uotila, J. [Univ. of Helsinki (Finland). Dept. of Applied Chemistry and Microbiology

1995-12-31

356

Innovative technologies for soil cleanup  

Energy Technology Data Exchange (ETDEWEB)

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.

Yow, J.L. Jr.

1992-09-01

357

Innovative technologies for soil cleanup  

International Nuclear Information System (INIS)

[en] 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

1992-01-01

358

Soil conditions and plant growth'  

Science.gov (United States)

Plants can respond to soil conditions in ways that can not readily be explained in terms of the ability of the roots to take up water and nutrients. Roots may sense difficult conditions in the soil and thence send inhibitory signals to the shoots which harden the plants against the consequences of a deteriorating or restrictive environment, especially if the plants' water supply is at risk. Generally, this behaviour can be interpreted as feedforward responses to the soil becoming too dry or too hard, or to the available soil volume being very small as with bonsai plants, or to roots' becoming infected with pathogens. However, soil that is too soft or in which the roots are forced to grow in very large pores can also induce large conservative responses, the significance of which is unclear. The inhibitory signals may affect stomatal conductance, cell expansion, cell division and the rate of leaf appearance. Their nature is still under debate, and the debate is becoming increasingly complex, which probably signifies that a network of hormonal and other responses is involved in attuning the growth and development of a plant to its environment. PMID:11841672

Passioura, J. B.

2002-02-01

359

Soil conditions and plant growth'  

UK PubMed Central (United Kingdom)

Plants can respond to soil conditions in ways that can not readily be explained in terms of the ability of the roots to take up water and nutrients. Roots may sense difficult conditions in the soil and thence send inhibitory signals to the shoots which harden the plants against the consequences of a deteriorating or restrictive environment, especially if the plants' water supply is at risk. Generally, this behaviour can be interpreted as feedforward responses to the soil becoming too dry or too hard, or to the available soil volume being very small as with bonsai plants, or to roots' becoming infected with pathogens. However, soil that is too soft or in which the roots are forced to grow in very large pores can also induce large conservative responses, the significance of which is unclear. The inhibitory signals may affect stomatal conductance, cell expansion, cell division and the rate of leaf appearance. Their nature is still under debate, and the debate is becoming increasingly complex, which probably signifies that a network of hormonal and other responses is involved in attuning the growth and development of a plant to its environment.

Passioura JB

2002-02-01

360

HUMUS SUBSTANCES AND SOIL FERTILITY  

Directory of Open Access Journals (Sweden)

Full Text Available The humus substances play an important role in obtaining high yields and stable over time. He is permanently double process: the humus improvement of organic material reaching the soil and the mineralization of components at different stages of humus improving, The results of this process is influenced by soil type, climate, irrigation, fertilization. The beneficial effect of humus substances on plant growth may be related to indirect effects (fertilization efficiency or reduce soil compaction) or direct (overall improvement in plant biomass). Factors influencing the humus improving are: climate, biological, pedological, that cultural and technological factors: plant debris, C/N of debris, application of organic and mineral fertilizers and herbicides absorption on humus substrates.Mineralization of soil organic matter, humus substances is thus favourably influenced by mineral fertilization. In this paper we studied the effect of fertilizers on soil humus (Ct), organic matter humus improved (Ce), the carbon content of humus acids (HFA). The interpretation of results was observed that the intensity of nitrification is influenced by humus substances existing total.

Cecilia Violeta NEAGU; Georgeta OPREA

2012-01-01

 
 
 
 
361

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; Besnik Gjongecaj; Deme Abazi

2013-01-01

362

Challenges of pedodiversity in soil science  

Science.gov (United States)

Soil diversity is not a completely new concept in soil science. It has been discussed from early times but it was not challenged this much broad. Ibañez with introducing the pedodiversity opened a new conceptual window to ease the induction of the soils complexity, spatial and temporal evolution and distribution. Pedodiversity now attracts more attention and goes to open new windows in soil science. Pedodiversity faces now with different challenges, which could be critical in its way on. Do the current soil diversity indices conceptually define all aspects of soil variability, or do we need to bind them with other characteristics like taxonomic distances? How is the soil individualism defined within the context of spatial variability and soil continuum? How are pedocomplexity, connectance, pedodiversity and soil spatial structure related? Can the changes of soil diversity be accounted as the rate of soil development? Can a range of pedodiversity index be a scale for soil series definition? Initial and some of current pedodiversity studies were/are focused on the concepts and measurement of pedodiversity and soil complexity indices of soilscape compared with the biological diversity and complexity. However, for the pedogenetic studies, the most important issues are the evolutionary concerns out of this approach compared with the other biotic systems. The new contexts, which should be more undertaken in future studies are: functional diversity, temporal diversity, study of soil and landform extinction and preservation. The last question could be: how pedodiversity could be changed under different understanding levels? A case study has been carried out in Charmahal and Bakhtiary province, Iran. Its objectives are the following: comparing the pedodiversity indices combined with and without taxonomic distances within tow replication of a geomorphic surface (Pi 111). What the pedodiversity says here? Did the unique calcification process which rules the soil formation here result in endemism or soil zonality? Do different pedodiversity indices correlate with the soil patterns?

Toomanian, N.; Esfandiarpoor, I.

2010-12-01

363

Energy efficient soil disinfestation by microwaves  

Energy Technology Data Exchange (ETDEWEB)

A major obstacle prohibiting the use of microwaves for soil disinfection and disinfestation is the large amount of energy required to obtain sufficient results. The present work presents an experimental study of the effect of initial soil temperature and soil moisture on energy consumption by application of microwaves for soil disinfection. All experiments were carried out by using a microwave generator of a nominal power output of 900 W. The ultra-high-frequency field (2450{+-}2 MHZ) was produced by a magnetron tube and channelled through a metal waveguide. The output opening of the waveguide was placed directly on the soil surface. It was found that a soil with 15% moisture content (w.b.) and an initial temperature of 20degC requires energy to be heated at a depth of 10 cm up to 61degC which is 3.2 times more than the energy required to heat the soil up to 5 cm depth at the same initial temperature. In general, the conversion of electric energy to useful microwave energy absorbed in the upper 10 cm soil was no more than 13% efficient in this field application. Heating a soil of 15% moisture content (w.b.), when the initial soil temperature is 40degC, requires 15 kWh/M{sup 2} or 42% less energy than the soil with same moisture content but at 20degC initial soil temperature. When the initial temperature is 40degC and the soil moisture is 5.5% (w.b.) only 7.4 kWh/M{sup 2} is required. It is concluded that humidity of the soil and initial soil temperature are critical for a low-cost use of microwaves for soil disinfestation, and a combustion of solarization and microwaves is proposed as an energy efficient technique of using microwaves for soil disinfestation. (Author)

Mavrogianopoulos, G.N.; Frangoudakis, A.; Pandelakis, J. [Athens Agricultural Univ., Athens (Greece)

2000-02-01

364

Estimating of the Soil Moisture in Brazil  

Science.gov (United States)

Soil moisture is a key variable in soil-atmosphere transfer processes. Soil moisture can be measured by direct and indirect techniques. Those methods are time consuming and impractical over large areas, such as Brazil. For this reason, soil moisture is generally estimated from the amount of water entering or draining from the soil profile by the water balance method. In this work, a soil water balance for Brazil was developed, using a new approximation that takes into account the spatial variability of soil characteristics. The water balance model used a simple equation, which is a function of the water availability, rainfall and potential evapotranspiration. The maximum soil water storage was derived from the field capacity and the wilting point using a pedo-transfer function (PTF). PTF allows the estimation of soil hydraulic properties from basic soil data, such as texture, organic carbon and bulk density. The evapotranspiration was estimated using the Penman-Monteith method. Based on the vegetation parameters provided by the SiB model, the potential evapotranspiration was calculated for the main Brazilian biomes, as defined in SiB. The mean soil moisture for the period 1971-1990 was derived combining historical rainfall data and evapotranspiration estimates. From the soil moisture climatology, regions with higher/lower soil moisture availability during El Nino (1982-1983)/La Nina (1988-1989) episodes were identified.

Rossato, Luciana

2002-01-01

365

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; H. Karimzadeh; R. Jafari

2013-01-01

366

Speciation of zinc in contaminated soils  

Energy Technology Data Exchange (ETDEWEB)

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 Zn{sup 2+}, 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 (K{sub d}) for Zn ranged from 17 to 13,100 L kg{sup -1} soil. The fraction of dissolved Zn bound to DOM varied from 60% to 98% and the soil solution free Zn{sup 2+} varied from 40% to 60% of the labile Zn. Multiple regression equations to predict free Zn{sup 2+}, 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.

Stephan, Chadi H. [Department of Chemistry, Universite de Montreal, P.O. Box 6128, Centre-Ville, Montreal, QC H3C 3J7 (Canada); Courchesne, Francois [Department of Geography, Universite de Montreal, P.O. Box 6128, Centre-Ville, Montreal, QC H3C 3J7 (Canada); Hendershot, William H. [Department of Natural Resource Sciences, Macdonald Campus, McGill University, 21111 Lakeshore, Ste-Anne-de-Bellevue, QC H9X 3V9 (Canada); McGrath, Steve P.; Chaudri, Amar M. [Agriculture and Environment Division, Rothamsted Research, Harpenden, Herts AL5 2JQ (United Kingdom); Sappin-Didier, Valerie [UMR TCEM, INRA, Centre de recherche Bordeaux-Aquitaine, BP 81, 33883 Villenave d' Ornon (France); Sauve, Sebastien [Department of Chemistry, Universite de Montreal, P.O. Box 6128, Centre-Ville, Montreal, QC H3C 3J7 (Canada)], E-mail: sebastien.sauve@umontreal.ca

2008-09-15

367

Salt Affected Soils Their Identification and Reclamation  

Directory of Open Access Journals (Sweden)

Full Text Available Salt affected soils are found throughout the world especially in arid and semi arid regions. Soil salinization is mainly due to the use of saline water for irrigation, seepage from the canals, an arid climate evaporation of salty soil waters from the soil surface over shallow water tables and poor drainage. Salt effected soils are grouped into saline, alkali and saline-alkali soils. Three different ways viz. scrapping, surface flushing and leaching are normally used for reclamation of these soils. Reclamation of salt affected soils by leaching is the best way of reclamation. Continuous and intermittent leaching are two techniques of water application during the leaching process. Continuous leaching is quicker but it consumes more water than intermittent leaching. Soil amendments (gypsum, sulphur or sulphuric acid) are usually needed for the reclamation of soils with high sodium content. By planting trees in soils with high water table and no drainage, soil reclamation process can be accomplished. Soil salinization can be prevented by using good quality water and by managing water table below root zone by providing surface of subsurface drainage.

A.A. Siyal; A. G. Siyal; Z. A.Abro

2002-01-01

368

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.

2008-01-01

369

Soils âField Characterization, Collection, and Laboratory Analysis  

Science.gov (United States)

Field characterization of soil profiles in coniferous and deciduous settings; sample collection of soils from different horizons; laboratory analysis of soil moisture, soil organic carbon (by loss on ignition), and grain size distribution (by sieving)

Biswas, Abir

370

Soils pollution; Pollution des sols  

Energy Technology Data Exchange (ETDEWEB)

This document brings together 12 testimonies of experts about the legal aspects, risks assessment and remedial actions relative to polluted soils: 1 - regulations and liabilities: French regulation about the modalities of management of a polluted site; the civil, penal and administrative liabilities in the domain of soil pollution; 2 - methods of risk evaluation: simplified evaluation, detailed evaluation, possible impacts on human health, water resources, goods and ecosystems; 3 - pollutions characterization: site characterization, analytical characterization of waters and soils polluted with hydrocarbons; 4 - decision-aid tools for the choice of a rehabilitation scenario: decision-aid and risk management-aid tools; 5 - cleansing methods; 6 - experience feedbacks: successful cleansing of the Akzo Nobel site at Ollainville (France). (J.S.)

Normant, E. [Ministere de l' Amenagement du Territoire et de l' Environnement, Direction de la Prevention des Pollutions et des Risques, 75 - Paris (France); Huglo, Ch. [Huglo Lapage et Associes Conseil, 75 - Paris (France); Darmendrail, D. [BRGM, 75 - Paris (France)] [and others

2000-10-01

371

IMPROVEMENT OF SOIL MOISTURE RETENTION  

UK PubMed Central (United Kingdom)

The process serves for the long-term improvement of soil moisture retention for the cultivation of plants (22) in a water-permeable, rapidly drying soil. A layer of cellulose absorption pads (10) containing a superabsorber and/or chips (14) acting as a moisture reservoir is introduced into a humus layer (16) or a layer of sand (18) below the usual working depth for cultivation. The pulps consist of complete, used absorption pads or absorption pads of manufacturing waste or chips (14) thereof. In addition to the usual horticultural and agricultural applications, the process allows for the urbanisation of soils in dry areas and in sandy and desert areas without any additional fixedly installed equipment.

LEONE Demetrio

372

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

1965-01-01

373

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; Muhammad Ateeq ur Rehman Malik; Muhammad Arshad

2001-01-01

374

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

375

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

376

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

Energy Technology Data Exchange (ETDEWEB)

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

Li, X.; Sawatsky, N. [Alberta Environmental Centre, Vegreville, Alberta (Canada)

1995-12-31

377

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

2007-01-01

378

Stool Soiling and Constipation in Children  

Science.gov (United States)

... causes of stool soiling? Stool soiling, also called encopresis, happens when children who are already toilet trained ... in bed Source Treatment Guidelines for Primary Nonretentive Encopresis and Stool Toileting Refusal by BR Kuhn, PH. ...

379

The soil use in rural areas  

Directory of Open Access Journals (Sweden)

Full Text Available The soil is becoming one of the crucial problems for the Nature and its proper functioning due to many reasons of its misusing or abusing. The market forces in agriculture are rapidly deteriorating the soil wild biodiversity and its capacity. The importance of the soil and its wild biodiversity, related to the water system and other ecological functions are presented in short outlines. Understanding the soil quality means assessing and managing soil that it functions optimally now and is not degradated for the future use. Evaluation of the soil quality in a different manner serves for agriculture embitterment and for keeping water and habitat organisms quality. Further, the instrument for soil protection policies implementation are given such as regional development planning, incentives for regional integration, social impacts oriented actions, education etc. The further soil decay will generally jeopardize the whole idea of sustainable development. Therefore it asks for more efficient understanding from decision makers, producers, but from planners as well.

Stojkov Borislav

2006-01-01

380

For Better Soil, Let Earthworms Toil.  

Science.gov (United States)

|This activity involves elementary students in investigating how earthworms affect soil fertility. An introduction discusses topsoil loss and the connections between soil and earthworm ecology. Materials needed and step-by-step procedure are provided. (LZ)|

Swinehart, Rebecca, Ed.

1995-01-01

 
 
 
 
381

Lunar soil as shielding against space radiation  

Energy Technology Data Exchange (ETDEWEB)

We have measured the radiation transport and dose reduction properties of lunar soil with respect to selected heavy ion beams with charges and energies comparable to some components of the galactic cosmic radiation (GCR), using soil samples returned by the Apollo missions and several types of synthetic soil glasses and lunar soil simulants. The suitability for shielding studies of synthetic soil and soil simulants as surrogates for lunar soil was established, and the energy deposition as a function of depth for a particular heavy ion beam passing through a new type of lunar highland simulant was measured. A fragmentation and energy loss model was used to extend the results over a range of heavy ion charges and energies, including protons at solar particle event (SPE) energies. The measurements and model calculations indicate that a modest amount of lunar soil affords substantial protection against primary GCR nuclei and SPE, with only modest residual dose from surviving charged fragments of the heavy beams.

Miller, J. [Lawrence Berkeley National Laboratory, MS 83R0101, 1 Cyclotron Road, Berkeley, CA 94720 (United States)], E-mail: miller@lbl.gov; Taylor, L. [Planetary Geosciences Institute, Department of Earth and Planetary Sciences, University of Tennessee, Knoxville, TN 37996 (United States); Zeitlin, C. [Southwest Research Institute, Boulder, CO 80302 (United States); Heilbronn, L. [Department of Nuclear Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Guetersloh, S. [Department of Nuclear Engineering, Texas A and M University, College Station, TX 77843 (United States); DiGiuseppe, M. [Northrop Grumman Corporation, Bethpage, NY 11714 (United States); Iwata, Y.; Murakami, T. [National Institute of Radiological Sciences, Chiba 263-8555 (Japan)

2009-02-15

382

Effects of pipeline construction on soil compaction  

Energy Technology Data Exchange (ETDEWEB)

A study was initiated in 1988 to evaluate the effects of pipeline construction on soil compaction in the province of Alberta. Cone penetration resistance (soil strength) of soils was monitored to a depth of 31.5 cm at 14 study areas. Soil strength measurements were taken from right-of-way locations as well as from an adjacent undisturbed control. Soil strength information from the 14 study areas suggests that pipeline construction procedures can cause changes in soil strength on pipeline rights-of-way. Decreases in soil strength on the RoW compared to adjacent controls are more common than increases. These differences in soil strength appear to be short lived. In the majority of cases most differences, both increases and decreases, had disappeared one year after construction.

Landsburg, S.L. [NOVA Gas Transmission Ltd., Calgary, Alberta (Canada); Cannon, K.R.; Finlayson, N.M. [Land Resources Network Ltd., Edmonton, Alberta (Canada)

1996-12-31

383

Numerical analysis of slopes in unsaturated soils  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Conventional constitutive models developed for saturated soils are inadequate when analysing problems involving unsaturated conditions. Although unsaturated constitutive models are available in the Imperial College Finite Element Program (ICFEP), there are aspects of unsaturated soil response that a...

Tsiampousi, Aikaterini

384

Evaluating Potential Groundwater Contamination from Contaminated Soils.  

Science.gov (United States)

Contamination of soils at toxic and hazardous waste sites can adversely affect groundwater and surface water. Water soluble materials can move in soil by leaching and percolation and by runoff. The project evaluated the toxicity of leachable toxicants fro...

J. R. Pratt P. V. McCormick K. W. Pontasch J. Cairns

1987-01-01

385

SOIL COMPACTION AND POULTRY LITTER EFFECTS ON FACTORS AFFECTING NITROGEN AVAILABILITY IN A CLAYPAN SOIL  

Science.gov (United States)

Soil compaction may affect N mineralization and the subsequent fate of N in agroecosystems. Laboratory incubation and field experiments were conducted to determine the effects of surface soil compaction on soil N mineralization in a claypan soil amended with poultry litter (i.e., turkey excrement mi...

386

EVALUATION OF THE ACCURACY OF A CENTRAL IOWA SOIL SURVEY AND IMPLICATIONS FOR PRECISION SOIL MANAGEMENT  

Science.gov (United States)

The movement towards precision agriculture has led to calls for soil maps that are more detailed and accurate than those offered in standard NCSS soil surveys. Studies have shown that soil variability can be greater than depicted in soil surveys; in fact, delineations that contain at least 50% of t...

387

Soil Loss Prediction (Using Rusle) and Comparison With Measured Soil Loss  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The main objective of this study was to predict soil loss from various field experiments and to compare the results with measured soil loss from the field to see the performance of Revised Universal Soil Loss Equation (RUSLE) in predicting the soil loss. The results of this study showed that there w...

Almas M.; T. Jamal

388

Fractal scattering of microwaves from soils.  

UK PubMed Central (United Kingdom)

Using a combination of laboratory experiments and computer simulation we show that microwaves reflected from and transmitted through soil have a fractal dimension correlated to that of the soil's hierarchic permittivity network. The mathematical model relating the ground-penetrating radar record to the mass fractal dimension of soil structure is also developed. The fractal signature of the scattered microwaves correlates well with some physical and mechanical properties of soils.

Oleschko K; Korvin G; Balankin AS; Khachaturov RV; Flores L; Figueroa B; Urrutia J; Brambila F

2002-10-01

389

Micronutrient soil tests and plant tissue analysis  

International Nuclear Information System (INIS)

[en] This paper briefly reviews recent trends in the development of micronutrient cation and anion soil tests. Special emphasis is placed on the need to develop a soil test for zinc which can adequately predict the change that takes place in the labile soil zinc pool after the land is flooded for rice production. Reference is made to the problems of interpretation of plant analysis results, especially in rice grown under flooded soil conditions. (author)

1974-09-23

390

Human-induced soil degradation activities  

Directory of Open Access Journals (Sweden)

Full Text Available Soil degradation is occurring over vast areas. The GLASOD and ASSOD projects reflect the present status of human-induced soil degradation and its impact on food productivity related to productivity changes observed in the recent past. However, there is a great need for well-documented, reliable soil information and other related data at national and regional levels to better understand and qualify the impact of changing soil conditions or biomass production.

Van Baren J.H. V.; Oldeman L.R.

1998-01-01

391

Soils of Europe; 1 : 20 000 000  

International Nuclear Information System (INIS)

The map is based on the physical atlas of the world at scale 1 : 10 000 000 (Acad. Sci. USSR, Moscow 1964) and the Soil geographical database of Europe at scale 1 : 1 000 000 (1998). Its construction reflects the latitudinal zonality of the European soils. Eight categories of types and subtypes and 6 combinations of soils were used. Glaciers and associations of mountain soils form an individual category. (authors)

2002-01-01

392

Pencycuron dissipation in soil: effect of application rate and soil conditions.  

UK PubMed Central (United Kingdom)

Dissipation of the fungicide pencycuron was examined under controlled laboratory conditions in clay loam soils from rice cultivated fields of alluvial soil (Typic udifluvent) and coastal saline soil (Typic endoaquept) at field rate, twice the field rate and 10 times the field rate with and without decomposed cow manure maintained at 60% of maximum water-holding capacity (WHC) and waterlogged soil condition. The half-life values depended on the initial concentrations of pencycuron. Pencycuron, in general, degraded fastest in coastal saline soil and in soil amended with decomposed cow manure at 60% of maximum WHC of soil.

Pal R; Chakrabarti K; Chakraborty A; Chowdhury A

2005-12-01

393

Soil Test Phosphorus Recovery from Livestock Manures Compared with Inorganic Fertilizer in Soil Incubations  

International Nuclear Information System (INIS)

This paper compared dairy and hen manure P recovery relative to fertilizer P recovery for two Nova Scotia soils with different antecedent soil test P (STP), incubated for 5, 15, 30, 60, and 110 days. Fertilizer equivalence of manure P was expressed as P recovery ratio in percentage points (%PRR). Repeated measures analysis with soil ph co variate revealed: (1) manure %PRR averaged 72% (low-STP soil) and 80% (medium-STP soil), (2) there were no significant differences in %PRR between dairy and hen manure, and (3) manure %PRR decreased with incubation time for the low-STP soil but not for the medium-STP soil. The soil ph co variate was significant for both low- and medium-STP soils, and the relationship with %PRR was positive for low- but not f