Studies of a new swine manure management system developed by USDA Agricultural Research Service (ARS) scientists confirm big benefits for the environment and for producers. The results showed the technology removed almost all the pathogens, odor-causing constituents and ammonia from manure wastewater, while reducing greenhouse emissions by 97%.
In addition, swine daily weight gain increased, feed conversion improved, animal mortality decreased and 5.6% more hogs were sold per growing cycle.
As an additional benefit, swine producers installing the new system may be able to sell greenhouse gas emission reduction credits and water quality credits.
The new system—actually the second generation of a version dating from 2003—utilizes solid-liquid separation and nitrogen and phosphorus removal processes which replace traditional anaerobic lagoon systems. The separated manure solids are composted and used as fertilizer and soil amendments.
The system was developed by ARS soil scientists Matias Vanotti and Ariel Szogi of ARS's Coastal Plains Soil, Water and Plant Research Center in Florence, S.C. They designed the system to meet North Carolina environmental performance standards, which are the strictest in the nation.
Vanotti and Szogi worked with Super Soil Systems USA of Clinton, N.C. Also collaborating were ARS microbiologist Patricia Miller of the agency's Environmental Microbial and Food Safety Laboratory in Beltsville, Md., and ARS chemist John Loughrin of ARS's Animal Waste Management Research Unit in Bowling Green, Ky.