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United States Department of Agriculture

Agricultural Research Service

Title: Soil Water Characteristics

Authors
item Saxton, Keith - USDA (RETIRED)
item RAWLS, WALTER

Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: November 2, 2004
Publication Date: November 2, 2004
Citation: Saxton, K.E., Rawls, W.J. 2004. Soil water characteristics [abstract]. Agronomy Abstracts.

Technical Abstract: Hydrologic analyses often involve the evaluation of soil water infiltration, conductivity, storage, and plant-water relationships. To define the variable soil water effects requires estimating soil water relationships for water potential and hydraulic conductivity which depend on soil characteristics such as texture, organic matter and structure. Field or laboratory measurement of these relationships is difficult, costly and often impractical for many hydrologic analyses. Estimates based on the generalities of reported data are often adequate for many purposes. Previous studies have shown that statistical correlations between soil texture, soil water potential and hydraulic conductivity can provide sufficiently accurate estimates for hydrologic analyses and decisions. An extensive data set based on modern laboratory methods were assembled and analyzed to provide improved estimates of soil water characteristics. These new equations based on a wide range of soil textures and organic matter and were combined with adjustments for the effects of density, gravel and salinity. These equations provide reasonably accurate soil water characteristic estimates and computer efficiency when combined with modern computer methodology to provide rapid and graphical solutions. It is recognized that the equations are the statistical average of a large data set, thus the results will vary somewhat for specific soils due to additional variables such as mineral type and structure.

Last Modified: 7/9/2014
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