Global warming potential of corn, soybean, and wheat production in organic, chisel till, and no-till farming systems

Global warming potential (GWP) is the net balance between a cropping system's loss or gain of soil carbon and greenhouse gas emissions. Partial GWP---based on change in soil carbon, soil N2O emissions, and CO2 emissions from direct and indirect energy use---was calculated for no-till (NT), chisel- till (CT), and organic (ORG) cornsoybean- wheat- legume rotations at the USDA-ARS (United States Department of Agriculture-Agricultural Research Service) Farming Systems Project (FSP) in Beltsville, MD. Overall, ORG had a lower partial GWP than NT and CT, while NT had a lower GWP than CT. While these differences are clear, it is important to note that if the amount of poultry litter applied to wheat and corn, respectively, is transported more than 42 km and more than 114 to 127 km, respectively, the emissions from fuel use would result in GWP for ORG that exceeds that for CT and NT.;[GRACEnetPublication]. This publication is based upon work supported by the Agricultural Research Service under the ARS GRACEnet Project.