Cropland erosion is a major cause of nonpoint source water pollution in the United States (EPA [23]). It is also perceived by some observers to pose a serious threat to the productivity of agriculture in some areas of the country (Batie [2]). Recent attention to these issues along with the criticisms of the adequacy of existing soil conservation programs have led to a substantial interest in the development of new policies for erosion control (GAO [24], GAO [25], USDA [22]).