Ag researchers find value in using manure, litter

Vernon, Tex.-A long-term study by a Texas AgriLife Research economist using pig and beef manure on irrigated corn fields found that manure generates higher economic returns than anhydrous ammonia. Dr. Seong Park undertook the research to demonstrate that animal manure benefits producers by reducing both waste management costs and the need for chemical fertilizers because it contains multiple essential crop nutrients. Park said the key to animal manure transitioning from a cost for disposal to a benefit as a fertilizer is determined by agronomic and economic factors such as chemical fertilizer costs and the equipment and labor needed to apply each. The Fertilizer Institute (TFI) in Washington, D.C., didn’t respond to a request for comment. Park’s efforts found that anhydrous ammonia was the most costly nitrogen source across all three equivalent nitrogen rates of 50, 150, and 450 pounds of nitrogen per acre, with costs of $30.86, $54.88, and $126.95 per acre, respectively. Swine effluent had the lowest costs at $12.06, $17.98, and $34.51 per acre for the three application rates. The lower costs for the swine effluent are associated with the ability to apply it through existing irrigation equipment, requiring only minimal purchase to pump from the lagoon to the center pivot, Park said. Another study by the Agricultural Research Service (ARS) at Mississippi State University found that chicken litter, a mixture of chicken manure and sawdust or other bedding material, is much more valuable as a fertilizer than previously thought. An ARS report noted that some cotton farmers in the Mississippi area are switching to chicken litter, while others are interested but reluctant without the cost comparisons, which are now available from the study by ARS Agronomist Haile Tewolde and his associates. They found that cotton yields peaked 12 percent higher compared to synthetic fertilizer yields, and came up with figures showing that chicken litter has a value of about $78 a ton compared to $61 a ton when figured by the traditional method.