Use of GUEST Technology to Parameterize a Physically‐Based Model for Assessing Soil Erodibility and Evaluating Conservation Practices in Tropical Steeplands

A general motivation that led to the development of GUEST was to seek a more physically based soil erodibility measure than that provided by the K factor in the USLE. This motivation was strengthened by the finding that use of the USLE methodology in the extensive wheatgrowing belt in Australia, where annual soil loss is very variable, required several decades of experimentation in order to determine the K factor with useful accuracy. This made the methodology inappropriate in such contexts (Edwards, 1987). Furthermore, the technique used to determine soil loss in establishing the USLE, thought to be suspect, was later shown to lead to serious underestimation of soil loss, especially in well structured soils (Ciesiolka et al., 2006).\u