ABSTRACT
Changes in U.S. agricultural policy could dramatically affect the ecological quality of streams, landscapes, and communities in the Corn Belt, the Mississippi River Basin (MRB), and the Gulf of Mexico (see Chapter 1; Figure 1-1). Agricultural lands in the MRB are the primary source of the nitrogen that causes a dead zone in the Gulf of Mexico, and most of that nitrogen is coming from the Corn Belt, where the proportion of land in farms is much higher than in the MRB as a whole (USDA NASS 2004; Chapters 2 and 15 in this book). For example, 88 percent of the surface area of Iowa (31,729,490 acres; 128,404 km2) is land in farms. In this chapter, we describe alternative futures for two agricultural watersheds in Iowa in order to examine how different policies, practices, and landscape patterns might produce both improved environmental quality and productive agricultural enterprises.
