See more from this Session: Modeling Processes of Plant and Soil Systems: II
Monday, November 1, 2010
Long Beach Convention Center, Exhibit Hall BC, Lower Level
Water deficit is the most common adverse environmental condition that can seriously reduce crop productivity. Crop simulation models could assist in determining alternate crop management scenarios to deal with water–limited conditions. However, prior to the application of crop models, the appropriate performance under different level of soil water conditions needs to be confirmed. Data from an irrigated trial conducted during May to November 2008 in northeast of Greeley, Colorado were used in this study. The irrigation treatments were 40, 55, 70, 85% of fully irrigated and 100% full water requirements. The experimental corn growth and development data as well as the daily evapotranspiration (ET) measured with the Bowen ratio–energy balance (BREB) system and the FAO–56 Penman–Monteith (PM) equation, and soil water content were compared with the corresponding simulated data using the Cropping System Model (CSM)–CERES–Maize model. The study showed that the model performed fairly well in simulating phenology, grain yield and biomass for all irrigation treatments. The CSM–CERES–Maize model with Priestley–Taylor option provided daily ET values that had a lower accuracy than those derived from the FAO–56 PM option for the fully irrigated treatment when compared with daily ET measured by the BREB system. There was also a good agreement between simulated and observed soil moisture content over time for the different depths of the various irrigation treatments. Overall, it can be concluded that the CSM–CERES–Maize model was able to predict water stress response of corn growth and development, evapotranspiration, and soil water content. These results confirmed that the model has the potential for use as a tool in agricultural water management to deal with water–limited condition.