Abstract

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.

Estimating Nitrogen and Phosphorus from Animal Manure

Nitrogen and phosphorus from manure were estimated from county-level animal populations of cattle and calves, cows and heifers that had calved, beef cows, milk cows, other cattle, layers (chickens) 20-weeks old and older, pullets for laying-flock replacement, broilers and other meat-type chickens, turkeys, total hogs and pigs, hogs and pigs used or to be used for breeding, other hogs and pigs, hogs and pigs sold, sheep and lambs, and horses and ponies retrieved from the 2002 Census of Agriculture (U.S. Department of Agriculture, National Agriculture Statistics Service, 2004). The procedures used in this report for estimating nitrogen and phosphorus from animal manure are from Ruddy and others (2006) and include the following: (1) estimating animal populations when the primary category population was not disclosed, (2) calculating nitrogen and phosphorus content of the animal manure on the basis of animal populations and estimates of nitrogen and phosphorus content in manure, and (3) estimating the component of nitrogen and phosphorus from confined and unconfined livestock.

Description of the County-Level Nutrient-Input Dataset

Estimates of nitrogen and phosphorus from animal manure for 2002 are presented in the spreadsheet dataset file ofr2013-1065_manure_2002.xlsx. The dataset and metadata are available online at http://water.usgs.gov/lookup/getspatial?ofr2013-1065_manure_2002. The dataset consists of county-level animal populations, estimated nitrogen and phosphorus content (in kilograms) of the manure from each animal group (cattle, hogs, poultry, and other), total nitrogen and phosphorus content (in kilograms) for all animal groups combined, and separate estimates of nitrogen and phosphorus from confined and unconfined livestock. Attribute definitions are listed in table 1. These data provide an estimate of nonpoint nitrogen and phosphorus inputs associated with manure and were developed to support national and regional assessments of water quality as part of the U.S. Geological Survey's National Water-Quality Assessment Program (Dubrovsky and others, 2010).

References Cited

Dubrovsky, N.M., Burow, K.R., Clark, G.M., Gronberg, J.M., Hamilton P.A., Hitt, K.J., Mueller, D.K., Munn, M.D., Nolan, B.T., Puckett, L.J., Rupert, M.G., Short, T.M., Spahr, N.E., Sprague, L.A., and Wilber, W.G., 2010, The quality of our Nation's waters—Nutrients in the Nation's streams and groundwater, 1992–2004: U.S. Geological Survey Circular 1350, 174 p. Available at http://pubs.usgs.gov/circ/1350/.

Ruddy, B.C., Lorenz, D.L., and Mueller, D.K., 2006, County-level estimates of nutrient inputs to the land surface of the conterminous United States, 1982–2001: U.S. Geological Survey Scientific Investigations Report 2006–5012, 17 p. Available at http://pubs.usgs.gov/sir/2006/5012/.

U.S. Department of Agriculture, National Agriculture Statistics Service, 2004, 2002 Census of Agriculture—State and County Data, Volume 1: Geographic Area Series, Washington, D.C. Available at http://www.agcensus.usda.gov/Publications/2002/index.asp.

First posted April 11, 2013