Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: July 23, 2003
Publication Date: November 2, 2003
Citation: Martin, M.A., Pachepsky, Y.A., Rawls, W.J. 2003. Entropy-based analysis of texture to estimate soil hydraulic proprties. [Abstract]. Agronomy Abstracts. p.194
Soil hydraulic parameters are needed in most projects on transport and fate of pollutants. Measurement of these parameters is labor- and time consuming, and pedotransferprocedures 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 has been put in searching for small number of parameters to effectively characterize soil texture for estimating soil hydraulic properties. We have developed a new, entropy-based index (EBI) of soil texture that shows presence of particle sizes dominating in particle size distributions. This index has a potential to reflect probable packing of soil particles, and therefore, to reflect not only soil texture but also soil structure. We computed the EBI for several soil hydraulic databases, included it in the list of possible predictors of soil hydraulic properties along with other soil basic properties, and applied the regression tree algorithm to find whether the EBI will serve as one of main variables-predictors to subdivide the database into homogeneous subsets of samples. We observed that the EBI always was in the list of main predictors for water retention in capillary range, where the estimations of hydraulic properties are notoriously difficult. Using the EBI is a promising approach to improve the accuracy of estimated soil hydraulic properties.