High value crops need high value inputs, particularly an adequate supply of fertilizer that can be applied when the crop needs it most.

More efficient use of fertilizer reduces input costs and significantly lowers both economic and environmental risks.

Solving some of these ongoing challenges has been a labor of love for USDA-ARS Soil Scientist Matias Vanotti since the mid-1990s. Though he has had some significant successes in removing ammonium from hog and poultry house waste, his latest breakthrough, he contends, can have a much bigger impact on the livestock industry worldwide.

Vanotti and his research team at the USDA-Agricultural Research Service (ARS) Coastal Plains Soil, Water, and Plant Research Center in Florence, S.C., developed a process of collecting ammonia from swine and poultry waste in membranes made from gas permeable polymers. The end product is high value liquid fertilizer with a high nitrogen content.

The membranes, which in a commercial setting will be placed under swine lagoons and poultry houses, have two cells.

One cell is filled with acid and the other with waste water from the livestock production facility.

The process extracts ammonia from the waste and mixes it with acids to form ammonia sulfate or nitrate, which can be used commercially as a source of liquid fertilizer for crops or other uses.                                

Vanotti and the USDA recently patented a new technology that uses these gas-permeable membranes to capture and recycle ammonia from swine and poultry wastewater. 

The membranes, Vanotti contends, can be adapted to commercial scale.

These membranes are similar to materials already used in waterproof outdoor gear and biomedical devices that add oxygen and remove carbon dioxide from blood.