Diane E. Stott1, Michel Cavigelli1, Curtis Dell2, Stephen Del Grosso3, Ronald F. Follett4, Alan J. Franzluebbers1, Jane M.F. Johnson5, Mark A. Liebig6, Tim B. Parkin7, and Jeffrey L. Smith1. (1) USDA-ARS, National Soil Erosion Research Laboratory, 275 South Russell Sreet, West Lafayette, IN 47907-2077, (2) USDA-ARS PSWMRU, Bldg 3702, Curtin Road, University Park, PA 16802, (3) USDA ARS NPA SPNR, 2150 Centre Avenue Building D, Suite 100, Fort Collins, CO 80526, (4) USDA-ARS, Soil Plant Nutrient Res., Fort Collins, CO 80526-8119, (5) USDA-ARS NCSCRL, 803 Iowa Avenue, Morris, MN 56267, (6) USDA-ARS-NGPRL, PO Box 459, 1701 SW 10th Avenue, Mandan, ND 58554-3054, (7) National Soil Tilth Laboratory, 2150 Pammel Drive, Ames, IA 50011-4420
Agricultural activities account for about 20% of the total human-induced warming effect due to emission of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). Changes in management, including minimizing or eliminating tillage, adding organic matter (e.g. cover crops, manure), and improving nitrogen management for enhanced efficiency, can convert agriculture from a net source to a net sink of greenhouse gas (GHG) emission. There is increasing interest among land managers, policy makers, GHG emitting entities, and carbon (C) brokers in using agricultural lands to sequester C and reduce GHG emission. Precise information is lacking, however, on how specific management practices in different regions of the U.S. impact soil C sequestration and the mitigation of GHG emission. GRACEnet represents a coordinated national effort by the Agricultural Research Service to provide information on the soil C status and GHG emission of current agricultural practices and to develop new management practices to reduce net GHG emission and increase soil C sequestration. GRACEnet has three overarching objectives: 1) Evaluate the soil C status and direction of change of soil C in existing typical and alternative agricultural systems, 2) Determine net GHG emission (CO2, CH4 and N2O) of current agricultural systems in existing typical and alternative agricultural systems, and 3) Determine the environmental effects (water, air and soil quality) of the new agricultural systems developed to reduce GHG emission and increase soil C storage. Since 2003, significant emphasis within GRACEnet has been placed on comparing common management scenarios at multiple locations throughout the U.S. While soils, crops, and conditions are location specific, consistent methods and detailed record keeping has been used to facilitate cross-location comparison and to ensure quality control.