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 farmscost
of transportation, liability, efficiency compared with commercial
fertilizerneed 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 SystemThis
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:
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