ENHANCED SYSTEM MODELS AND DECISION SUPPORT TOOLS TO OPTIMIZE WATER LIMITED AGRICULTURE
Location: Agricultural Systems Research Unit
Title: Simulation of Climate Change Impacts on Wheat-Fallow Cropping Systems
Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: April 21, 2009
Publication Date: November 1, 2009
Citation: Ko, J., Ahuja, L.R., Kimball, B.A., Anapalli, S., Ma, L., Green, T.R., Wall, G.W., Pinter Jr, P.J. 2009. Simulation of Climate Change Impacts on Wheat-Fallow Cropping Systems. ASA-CSSA-SSSA Annual Meeting Abstracts.
Agricultural system simulation models are predictive tools for assessing climate change impacts on crop production. In this study, RZWQM2 that contains the DSSAT 4.0-CERES model was evaluated for simulating climate change impacts on wheat growth. The model was calibrated and validated using data from the Free Air CO2 Enrichment (FACE) experiment conducted at Maricopa, Arizona, USA from 1992 to 1997. The validated model was then used to simulate possible climate (temperature, CO2, and precipitation) change impacts on wheat-fallow rotations under conventional tillage (CT) and no tillage (NT) at Akron, Colorado, USA. Historical climate (1912-2007) and GCM projected and regionally downscaled climate change scenarios were used. Simulations of the FACE experiment demonstrated that the crop model reasonably simulated wheat responses to elevated CO2 conditions. Enhanced water use efficiency under the elevated CO2 was also correctly simulated. Simulation results with the historical climate showed that tillage affected crop growth more than CO2. Under both CT and NT, simulations with the projected climate showed that production decline due to temperature change can dominate over the CO2 fertilization effect on crop yield in the semiarid condition of Colorado. The study demonstrated the potential of RZWQM2 for climate change impact assessments.