THE DYNAMICS OF SOIL-EROSION IN US AGRICULTURE

Soil erosion has both on-farm and off-farm impacts. Reduction of soil depth can impair the land's productivity, and the transport of sedimen ts can degrade streams, lakes, and estuaries. To address this problem, soil conservation policies have existed in the United States for over 60 years. Initially, these policies focused on the on-farm benefits o f keeping soil on the land and increasing net farm income. Beginning i n the 1980s, however, policy goals increasingly included reductions in off-site impacts of erosion. The Food Security Act of 1985 was the fi rst major legislation explicitly to tie eligibility to receive agricul tural program payments to conservation performance. The Federal Agricu lture Improvement and Reform Act (FAIR) of 1996 modifies the conservat ion compliance provisions by providing farmers with greater flexibilit y in developing and implementing conservation plans. As a consequence of conservation efforts, total soil erosion between 1982 and 1997 was reduced by 42% and the erosion rate fell from 8.0 tons per acre in 198 2 to 5.2 tons per acre in 1997. Still, soil erosion is imposing substa ntial social costs. In 1997 these costs are estimated to have been app rox. US$29.7 billion. To further reduce soil erosion and thereby mitig ate its social costs, there are a number of policy options available t o induce farmers to adopt conservation practices including education a nd technical assistance, financial assistance, research and developmen t, land retirement, and regulation and taxes. (C) 1998 Elsevier Scienc e B.V. All rights reserved.