Long Term Organic Comparisons in the US.

This review analyzes organic production compared with conventional systems in long-term organic experimental trials across the U.S. Beginning with the Rodale Institute’s Farming Systems Trial (FST) in 1981, and the University of California-Davis’ Sustainable Agriculture Farming Systems (SAFS) experiment (1988), we will review productivity metrics, environmental footprint, and economic performance of these longer-term trials compared to the trials started 10 to 20 years ago, including the University of Wisconsin’s Integrated Cropping Systems Trial (WICST), UC-Davis’ Long-Term Research in Agricultural Sustainability (LTRAS) trial, USDA-ARS Beltsville, Maryland’s Farming Systems Project (FSP), the University of Minnesota’s Variable Input Crop Management Systems (VICMS) trial, and Iowa State University’s Long-Term Agroecological Research (LTAR) experiment. Common outcomes across all sites include the correlation between increased productivity and greater temporal and spatial diversity in organic sites. Enhanced carbon sequestration has also been a consistent result with longer organic crop rotations. Because of the variability in adherence to certified organic regulations, and application of organic price premiums in economic analysis, sites will be organized by the specific goal of the experimental trial, based on solely research criteria, or both research and demonstration purposes for the local farming community. Also discussed will be long-term sites without conventional counterparts, such as the USDA-ARS Salinas Organic Cropping Systems (SOCS), which experiments with cover crops and compost to improve soil management and nutrient use efficiency in organic vegetable crops. Linking long-term trials to facilitate greater dissemination of research results will increase the number of farmers transitioning to organic agriculture, which is the long-term goal of the LTAR site.