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Washington, D.C. – Ongoing research at the U.S. Department of Agriculture’s (USDA) Sustainable Agricultural Systems Lab (SASL) finds that organic grain production reduces greenhouse gas emissions relative to chemical-intensive no-till and chisel-plow production systems. In fact, the research concludes that the organic system removes more greenhouse gases from the atmosphere than it contributes, while the other systems result in net increases. The results are based on data from comparable three-year crop rotations maintained for each production system at the Lab’s farm in Beltsville, MD under the direction of Michel Cavigelli, PhD. The rotations mirror typical commercial grain production operations in the mid-Atlantic region that begin with corn followed by a rye grass cover crop, rotate to soybeans and winter wheat in the second year, and conclude with a legume crop. Dr. Cavigelli’s team identified the substantial energy savings achieved in the organic system by using natural fertility sources, especially for nitrogen, as the critical factor in reducing its overall impact on climate change.

Previous research shows that carbon dioxide and nitrous oxide are the two most potent greenhouse gases that are produced and released as a consequence of crop production. It is also known that, due to its specific molecular properties, nitrous oxide is approximately three hundred times more powerful than an equivalent amount of carbon dioxide. The USDA research calculated how much carbon dioxide was gained or lost by measuring changes in soil organic matter and also measured the nitrogen added for crop consumption that instead escaped as nitrous oxide. Combining this data with standardized figures for the energy expended (and therefore carbon dioxide released through fuel consumption) to operate each system -the number of tractor passes, for example- provided a snapshot of their respective contributions to climate change.