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Simulating Canopy Transpiration and Photosynthesis of Corn Plants under Contrasting Water Regimes Using a Coupled Model
- A process-based corn simulation model (MaizSim) was coupled with a two-dimensional soil simulator (2DSOIL) to simulate transpiration and photosynthesis of corn under contrasting water regimes. To improve the simulation of stomatal reaction to drought stress, a hydraulic stomatal control algorithm was implemented in the coupled photosynthesis-stomatal conductance module. Corn plants were grown in sunlit growth chambers and irrigated at three different frequencies. Simulated soil water content, transpiration, and photosynthesis rates were compared with those measured in the chambers. Comparison among simulations and measurements indicated that the coupled model was able to simulate the changes in soil water contents as well as the changes in transpiration and photosynthesis rates of corn plants under varying water status over the growing season. It was also found that the simulated photosynthesis rates were not as sensitive to reduction in stomatal conductance as the simulated transpiration rates. Reasons for this difference are discussed from the modeling viewpoint. This result agreed with the differences in sensitivity of photosynthesis and transpiration to changes in stomatal closure that have been reported in the literature. These results suggest that the coupled model not only is a valuable tool in studying corn transpiration and photosynthesis under drought stress, but it also provides a platform to implement and evaluate algorithms in studies of corn crop water dynamics and CO 2 assimilation.
Yang, Y. , Kim, S.H. , Timlin, D.J. , Fleisher, D.H. , Quebedeaux, B. , Reddy, V.R.
Zea mays , corn , photosynthesis , transpiration , crop models , simulation models , soil water content , soil water regimes , water stress , drought , stomatal conductance
- Includes references
- Transactions of the ASABE 2009 May-June, v. 52, no. 3
Journal Articles, USDA Authors, Peer-Reviewed
- Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.