Changing Poultry Manure into a
By Don Comis
November 28, 2000
Its a case of three wastes
making a resource. Wastes from drinking water treatment plants and industrial
plants have made poultry litter a safer fertilizer for nearby farms.
Alum in the water treatment residues and iron in certain industrial residues
strongly bind the phosphorus in poultry manure. This reduces water-soluble
concentrations of phosphorus, making it much less likely to wash into
waterways. The water treatment residues also contain liming materials which can
make soils less acidic.
Recycled as fertilizer, manure treated with these byproducts can improve
poor soils inexpensively and help farmers continue to use poultry litter (a
manure and sawdust mixture) as fertilizer. Eton E. Codling, an
Agricultural Research Service soil
scientist at Beltsville, Md., made the finding in a lab study announced in the
current issue of the Journal
of Environmental Quality. ARS is the chief scientific research agency
for the U.S. Department of Agriculture.
Spurred by toxic outbreaks of the microbe Pfiesteria piscicida in
tributaries of the Chesapeake Bay, Maryland is phasing in the countrys
strictest limitations on farm use of poultry litter and other phosphorus
fertilizers. Phosphorus washed into waterways is thought to be a possible cause
of Pfiesteria outbreaks. Farmers with soils measured at the highest levels of
water-soluble phosphorus would not be able to apply poultry litter or other
phosphorus fertilizer until the levels subsided.
In his lab study, Codling used soils and poultry litter from three such
farms--all long- established poultry farms--along with byproducts from
Chesapeake Bay area facilities. He plans to test the litter-byproduct mixtures
in corn and soybean fields on these farms.
Scientific contact: Eton E. Codling, ARS
Laboratory, Beltsville, Md., phone (301) 504-5708, fax (301) 504-5048,