The environmental implications of soil erosion in the United States.

摘要: Soil erosion has both on-farm and off-farm impacts. Reductionof soil depth can impair the land’s productivity, thetransport of sediments degrade streams, lakes, estuaries. Since 1933, conservation policies have existedin United States. Originally they focused on on-farmbenefits keeping land increasing net farmincome. Beginning in 1980s, however, policy goalsincreasingly included reductions off-site impacts erosion.As a consequence efforts associated withexplicit U.S. government policies, total between1982 1992 was reduced by 32% sheet rillerosion rate fell from an average 4.1 tons per acre yearin 1982 to 3.1 while wind ratefell 3.3 year 2.4 tonsper over same period. Still, isimposing substantial social costs. These costs are estimated tobe about $37.6 billion annually. To further reduce erosionand thereby mitigate its costs, there number ofpolicy options available induce farmers adopt conservationpractices including education technical assistance, financial research development, retirement, andregulation taxes.