ABSTRACT
The impact of agriculture on the earth's ecosystems is unparalleled by any other land use in its spatial extent and intensity of influence (Matson et al. 1997). Humans have had devastating impacts on global biodiversity and biogeochemical cycles (Puckett 1994; Alexander et al. 1996; Vitousek et al. 1997a , 1997b; Sala et al. 2000), and changing agricultural patterns and practices could help to ameliorate those impacts (OECD 2002). We have envisioned alternative futures for agriculture in one of the most productive and intensively cultivated regions of the world, the U.S. Corn Belt. Our results suggest that federal policy could promote ecological, social, and economic well-being at the same time as it reduces the environmental impacts of agriculture on terrestrial and aquatic ecosystems and cities downstream, from the upper reaches of the Mississippi River to the Gulf of Mexico.
