HR: 14:50h
AN: B33F-05    [Abstracts]
TI: Global Scale DAYCENT Model Analysis of Greenhouse Gas Mitigation Strategies for Cropped Soils
AU: * Del Grosso, S
EM: delgro@nrel.colostate.edu
AF: USDA-ARS-NPA-SPNR, 2150 Centre Ave Bldg D, Suite 10, Fort Collins, CO 80526 United States
AU: * Del Grosso, S
EM: delgro@nrel.colostate.edu
AF: Natural Resource Ecology Lab, Colorado State University, Fort Collins, CO 80523 United States
AU: Parton, W
EM: billp@nrel.colostate.edu
AF: Natural Resource Ecology Lab, Colorado State University, Fort Collins, CO 80523 United States
AU: Ojima, D
EM: dennis@nrel.colostate.edu
AF: Natural Resource Ecology Lab, Colorado State University, Fort Collins, CO 80523 United States
AU: Deangelo, B
EM: Deangelo.Ben@epamail.epa.gov
AF: USEPA, 1200 Pennsylvania Ave NW, Washington, DC 20460 United States
AU: Rose, S
EM: rose.steven@epa.gov
AF: USEPA, 1200 Pennsylvania Ave NW, Washington, DC 20460 United States
AB: Conversion of native vegetation to cropland and intensification of agriculture typically results in increased greenhouse gas (GHG) emissions and NO3 leaching. Agriculture is responsible for ~50% and ~70%, respectively, of the anthropogenic emissions of CH4 and N2O. Agriculture is also the primary contributor of eutrophication of aquatic systems from nutrients that are runoff or leached from cropped fields into waterways. Regional and larger scale estimates of GHG emissions and NO3 leaching are usually based on IPCC emission factor methodology, which is associated with high uncertainty. Process based models, such as DAYCENT, are just beginning to be used for national inventories of GHG emissions. The methodology used to conduct DAYCENT global and regional scale simulations of three major crops (corn, soybean, wheat) under baseline and alternative management is described in detail by Ojima et al. in this session. We compared model generated baseline GHG emissions and N losses for irrigated and rainfed cropping with land use alternatives intended to reduce GHG emissions. Mitigation scenarios considered are: nitrification inhibitors, split fertilizer application, N fertilizer reduction, and no-till cultivation. Simulations suggest that use of nitrification inhibitors leads to the largest reduction in N losses (~10%) and conversion to no till can store C and further offset GHG emissions associated with agriculture. Reduced fertilizer resulted in lower N losses, but crop yields were also reduced. Use of nitrification inhibitors and split fertilizer application both led to increased (~6%) crop yields. Future simulations will explore interactions between different mitigation options.
DE: 0402 Agricultural systems
DE: 0414 Biogeochemical cycles, processes, and modeling (0412, 0793, 1615, 4805, 4912)
DE: 0469 Nitrogen cycling
DE: 1625 Geomorphology and weathering (0790, 1824, 1825, 1826, 1886)
SC: Biogeosciences [B]
MN: Fall Meeting 2005