HR: 14:30h
AN: B33F-04    [Abstracts]
TI: Global Estimates of Trace Gas Fluxes Affected by Land Use Change and Irrigation of Major Crops
AU: * Ojima, D S
EM: dennis@nrel.colostate.edu
AF: Natural Resource Ecology Lab/Colorado State University, Campus Delivery 1499 NREL/CSU, Fort Collins, CO 80523-1499 United States
AU: Del Grosso, S
EM: delgro@nrel.colostate.edu
AF: USDA ARS NPA, Soil Plant Nutrient Research 2150 Centre Ave., Bldg D, Suite 10, Fort Collins, CO 80526 United States
AU: Parton, W J
EM: billp@nrel.colostate.edu
AF: Natural Resource Ecology Lab/Colorado State University, Campus Delivery 1499 NREL/CSU, Fort Collins, CO 80523-1499 United States
AU: Keough, C
EM: cindyk@nrel.colostate.edu
AF: Natural Resource Ecology Lab/Colorado State University, Campus Delivery 1499 NREL/CSU, Fort Collins, CO 80523-1499 United States
AB: Cropland conversions have altered many fertile regions of the earth and have modified the biogeochemical and hydrological cycling in these regions. These croplands are significant sources of N trace gas emissions however, the extent of changing trace gas emission due to land management changes and irrigation need further analysis. We use the DAYCENT biogeochemical model which is a daily time step version of the CENTURY model. DAYCENT simulates fluxes of N2O between croplands and the atmosphere for major crop types, and allows for a dynamic representation of GHG fluxes that accounts for environmental conditions, soil characteristics, climate, specific crop qualities, and fertilizer and irrigation management practices. DAYCENT is applied to all world cropland regions. Global datasets of weather, soils, native vegetation and cropping fractions were mapped to an approximate 2° x 2° resolution. Non-spatial data (such as planting date and fertilizer application rates) were assigned as point values for each region (i.e. country), and were assumed to be similar within crop types across the region. Three major crops were simulated (corn, wheat and soybeans) under both irrigated and non-irrigated conditions. Results indicate that N2O emission for maize and soy bean increase between 3 to 10%, where as wheat emission decline by about 1% when irrigated systems are compared to non-irrigated systems.
DE: 0402 Agricultural systems
DE: 0414 Biogeochemical cycles, processes, and modeling (0412, 0793, 1615, 4805, 4912)
DE: 1615 Biogeochemical cycles, processes, and modeling (0412, 0414, 0793, 4805, 4912)
SC: Biogeosciences [B]
MN: Fall Meeting 2005