Each year, U.S. farmers use about 3.7 billion pounds of phosphorus fertilizer, which is mined from underground phosphorus deposits around the world. Now, a team of U.S. Department of Agriculture researchers has found a way to extract phosphorus from poultry manure.

In 2006, the United States produced 9 million broilers and a large volume of litter rich in phosphorus and nitrogen, according to information from the USDA’s Agricultural Research Service. Although poultry litter is typically used by farmers to fertilize their field crops, it usually contains more phosphorus than the crops need. The excess phosphorus can wash away and pollute nearby rivers and streams.

The ARS is patenting a process developed by soil scientists Ariel Szogi, Matias Vanotti, and Patrick Hunt to remove and recover the phosphorus from poultry litter. The process removes up to 80 percent of the phosphorus while leaving the nitrogen behind. The treated litter can be applied to fields as a balanced fertilizer, used again as a bedding material, or be used for bioenergy production.