THE INTERTEMPORAL IMPACT OF SOIL-EROSION ON NONUNIFORM SOIL PROFILES - A NEW DIRECTION IN ANALYZING EROSION IMPACTS

Soil erosion studies by economists have utilized relatively simple yie ld response functions compared to productivity simulation models used by soil scientists in order to endogenously solve for optimal manageme nt schemes. This paper combines the optimization techniques of previou s economic studies with a more complex measure of soil productivity th an simply soil depth which has been used previously. An illustrative m odel demonstrates how erosion affects different types of soil profiles found in the United States and isolates three different ways that ero sion can impact productivity. Estimation procedures that do not accoun t for the non-uniform nature of soil profiles can misstate the impact of soil erosion on cropland productivity. The framework, though perhap s overly simplified for direct use, disentangles the impacts of soil e rosion into substitution, mixing and depth effects and suggests how va ried profiles should be managed in different ways according to how eac h is impacted by erosion. (C) 1997 Elsevier Science Ltd. All rights re served.