A modeling framework addresses manure management policies within the Chesapeake Bay watershed. Policy focus is on manure-land application at agronomic rates, as proposed under the EPA/USDA Unified Strategy. Manure-nutrient flows are assessed subject to assimilative capacity of farmland. National...

Federal policy on manure management has focused on water-quality protection. However, animal agriculture is an important source of ammonia-nitrogen and other air emissions, increasing attention on air-quality concerns. Policies to address air emissions would influence both the costs of meeting...

In 2010, a Total Maximum Daily Load (TMDL) was established for the Chesapeake Bay, defining the limits on emissions of nitrogen, phosphorus, and sediment necessary to reverse declines in the Bay’s quality and associated biological resources. Agriculture is the largest single source of...

This report relies on fi ndings from several national surveys and current literature to assess water resource use and conservation measures within the U.S. irrigated crop sector. U.S. agriculture accounts for 80-90 percent of the Nation’s consumptive water use (water lost to the environment by...

Global climate models predict increases over time in average temperature worldwide, with significant impacts on local patterns of temperature and precipitation. The extent to which such changes present a risk to food supplies, farmer livelihoods, and rural communities depends in part on the...