Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 13 of 13 for “"soil variability"”.
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Discriminating and mapping soil variability with hyperspectral reflectance data.
The classification and mapping of soils and soil variability is important for a variety of environmental and agricultural applications. Advances in precision agriculture, better understanding of environmental processes and improvements in mathematical models used to predict and understand landscape …
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Modelling the effects of soil variability and vegetation on the stability of natural slopes.
It is well recognised that the inherent soil variability and the effect of vegetation, in particular the effect of tree root reinforcement, have a significant effect on the stability of a natural slope. However, in practice, these factors are not commonly considered in routine slope stability …
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Soil Spatial Variability: Structures, Models, and Their Effects on Crop Yield Variability
… variables accounted for more than 80% of total soil variability. Component regression accounted for about 52%, and 39% of soybean and corn yields variability respectively. Particle size distribution and organic matter by influencing moisture and nutrient dynamics, were the most important factors …
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Soil degradation: Its aspects and modelling
… region, Sudan. In order to investigate the soil degradation aspects in the study area, its causal, rate per time and mapping; the remote sensing and GIS technologies were used beside the routine soil survey and laboratory analyses. Quantitative information on soils degradation and vegetation …
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Evaluation of reclaimed coal-mined prime farmland based on soil characteristics in lieu of the current yield-based approach
… for methods to expedite this process. A soil property-based model could relieve this burden and ensure the most efficient process for returning crop production fields to the landowner. The objective of my work was to develop a soil-based model to replace the current crop yield-based …
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The variability and geomorphology of Appling, Cecil, and Davidson soils on sideslopes in the Virginia Piedmont
Delineations of Applinq, Cecil, and Davidson soils were sampled on a grid pattern (4 to 9 m spacings), using a bucket auger, to determine their modal character and variability with regard to various chemical and morphological parameters. Delineations were located on south-southwest facing, 5 to 12% …
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Evaluation of an In Situ Measurement Technique for Streambank Critical Shear Stress and Soil Erodibility
… streambank critical shear stress (Ï c) and soil erodibility (kd). Previous research showed streambank kd and Ï c can vary by up to four orders of magnitude at a single site; therefore, it is essential to determine if the large range is due to natural variability in soil properties or errors …
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An approach to studying soil-landscape relationships in Virginia
… methods and techniques were used to examine soil-landscape relationships for residual and colluvial soils of Virginia. Soil micromorphology indicated that although some BC and C horizons in the field appeared structureless, evidence of pedogenic process was observed. These were designated as …
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Quantifying Properties and Variability of Expansive Soils in Selected Map Units
A study of 12 expansive soils in four major physiographic provinces in Virginia was initiated to examine and quantify the relationship between shrink-swell potential, shrink-swell indices, and soil properties. The mineralogy classes, soil series, and (physiographic provinces, parent materials) …
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Soil chemistry and ecology on a restoration trajectory of a coastal sandplain forest, Punakaiki, New Zealand
… the interactive role of vegetation and soil biogeochemistry on an ecological restoration trajectory on the West Coast of New Zealand. The Punakaiki Coastal Restoration Project (PCRP) was developed to restore degraded land to a more natural vegetation, resembling the original sandplain …
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Switchgrass Yield, Nutrient Uptake, And Rhizosphere Microbial Community Composition As Affected By Cultivar And Soil Fertility
… a bioenergy crop on fragile or low-productivity soils, reserving prime agricultural land for food crops. The objectives of this dissertation were to evaluate switchgrass and mixed native perennial production and nutrient removal as a function of nitrogen (N) and phosphorus (P) application, …
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Comparing plant yield and composition with soil properties using classical and geostatistical techniques
… crop requirements, the spatial variation of soil and plant properties within a field can be managed with the use of geostatistical techniques. Some work has also been done to evaluate the use of geostatistics in the design of agricultural field experiments to provide better field …
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Modeling Spatial Variability of Field-Scale Solute Transport in the Vadose Zone
Spatial heterogeneity in the soil system has a profound influence on the flow of water and chemicals in the unsaturated zone. Incorporating intrinsic soil variability and extrinsic variability into root zone leaching models will provide a better representation of pollutant distribution in natural …