County-level estimates of nitrogen and phosphorus from animal manure for the conterminous United States, 2002

County-level nitrogen and phosphorus inputs from animal manure for the conterminous United States for 2002 were estimated from animal populations from the 2002 Census of Agriculture by using methods described in U.S. Geological Survey Scientific Investigations Report 2006–5012. These estimates of nitrogen and phosphorus from animal manure were compiled in support of the U.S. Geological Survey’s National Water-Quality Assessment Program.