Manure Management

Livestock and poultry manure applied to farmland is a valuable source of organic nutrients, but manure nitrogen and phosphorus in excess of the farm's crop requirements can compromise water quality. Many confined animal operations are unable to use all manure nutrients produced on land under their control.

This has prompted concern commensurate with the increasing concentration of animal feeding operations, which also tend to be specialized and thus have less cropland on which to apply manure. A report, Confined Animal Production and Manure Nutrients, uses survey data to estimate the number of confined animals, the amount of manure nutrients, and the capacity of nearby land to assimilate these nutrients. Among its findings:

• The number of confined livestock farms declined by half from 1982 to 1997, while the number of confined animal (1 unit=1,000 lbs. of live animal weight) units increased 10 percent.
  
  
• Most farms have adequate land on which to agronomically apply the manure produced on the farm, including 78 percent of farms for manure nitrogen and 69 percent for phosphorus.
  
  
• Manure that is produced on farms that cannot fully apply it to their own land accounts for over 60 percent of manure nitrogen and 70 percent of manure phosphorus.
  
  
• The quantity of excess onfarm manure nutrients increased in all regions over 1982-97, with the greatest quantity increase in the Southern Seaboard, and the greatest percentage increase in the Heartland.

This report lays the groundwork for assessing the economic feasibility of land application as a manure management strategy. Barriers to moving manure to other farms—cost of transportation, liability, efficiency compared with commercial fertilizer—need to be studied. For areas without adequate land, alternatives to local land application, such as energy production, will need to be developed.

For more ERS information on this topic, see:

Confined Animal Production Poses Manure Management Problems (Agricultural Outlook, Sept. 2000).

Confined Animal and Manure Nutrient Data System—This data product  provides State and national data on confined animal numbers and associated manure nutrients. These data are based on analysis of the 1982, 1987, 1992, and 1997 Censuses of Agriculture by year, geographic area, animal type, and confinement status.

The following briefing rooms for additional resources, including questions and answers on animal waste, water quality, environmental programs, nutrient use and management, and more:

Chapters in Agricultural Resource and Environmental Indicators for background on water quality issues, programs, and more: