Mining Manure for Phosphorus
By Ann Perry
February 29, 2008
Underground phosphorus deposits
around the world are mined for use as a much-valued fertilizer. Now
Agricultural Research Service (ARS) soil
Hunt have found a way to mine the phosphorus in poultry manure.
In 2006, the United States produced 8.9 billion broilersand piles and
piles of residual litter rich in phosphorus and nitrogen. Although poultry
litter is typically used by farmers to fertilize their field crops with these
two nutrients, it usually contains more phosphorus than the crops need. The
excess phosphorus has the potential to wash away and pollute nearby rivers and
Szogi, Vanotti and Hunt have developed a method to obtain the phosphorus in
poultry litterconsisting of a rapid removal and recovery of phosphorus in
solid formwhich theyve dubbed Quick Wash. ARS has
applied for a patent on this process.
The process selectively removes up to 80 percent of the phosphorus from
poultry litter while leaving the nitrogen. The washed poultry litter can be
safely applied to farm fields as a balanced fertilizer or used again as a
bedding material. It can also serve as a feedstock for bioenergy production.
U.S. farmers use some 3.7 billion pounds of phosphorus in annual crop
production. But poultry and other livestock produce about 1 billion pounds more
phosphorus than livestock producers can use.
This innovation provides an environmentally sound phosphorus recovery system
that livestock producers can use to manage the excess phosphorus in manure.
Poultry producers also benefit by producing a concentrated phosphorus product
that can be moved easily off farms and reused as fertilizer.
ARS is interested in finding business partners to move the product to
Szogi, Vanotti and Hunt work at the
Coastal Plains Soil, Water and Plant Research Center in Florence, S.C. ARS
is the U.S. Department of Agriculture's
chief scientific research agency.