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ARS Home » Pacific West Area » Maricopa, Arizona » U.S. Arid Land Agricultural Research Center » Plant Physiology and Genetics Research » Research » Publications at this Location » Publication #307289
Title: Simulation of climate change impacts on grain sorghum production grown under free air CO2 enrichment

Author
item FU, TONGCHENG - Chonnam National University
item KO, JONGHAN - Chonnam National University
item Wall, Gerard - Gary
item Pinter Jr, Paul
item Kimball, Bruce
item OTTMAN, MICHAEL - University Of Arizona
item KIM, HAN-YONG - Chonnam National University

Submitted to: Agricultural and Forest Meteorology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/1/2016
Publication Date: 7/15/2016
Citation: Fu, T., Ko, J., Wall, G.W., Pinter Jr, P.J., Kimball, B.A., Ottman, M.J., Kim, H. 2016. Simulation of climate change impacts on grain sorghum production grown under free air CO2 enrichment. Agricultural and Forest Meteorology. 30:311-322. doi:10.115/intag-2016-0007.

Interpretive Summary: In this study, a sorghum crop growth model was calibrated and validated for simulations of biomass and grain yield under present-day and elevated carbon dioxide concentrations, and under well-watered and water-stressed conditions at Maricopa, Arizona, USA. The effects of water and temperature were greater than carbon dioxide and the model reasonably simulated these effects. We also presented sensitivity of sorghum to individual climate change variables for future model application as well as simulation with projections from twenty-one Global Circulation Models that include increased temperature and precipitation changes along with increases in atmosphere carbon dioxide concentration for 2080-2100. The beneficial effect of carbon dioxide on yield was cancelled by the negative effects of temperature increases, whereas precipitation changes had negligible effects. The sorghum model responded satisfactorily to the climate change driving factors including carbon dioxide concentration, temperature, and precipitation. These results suggest that an increase in water demand for sorghum production is anticipated. They also demonstrate the utility of the model for simulating climate change impacts on sorghum production and soil water availability.

Technical Abstract: Potential impacts of global climate change on crop productivity have drawn much attention in recent years. To investigate these impacts on grain sorghum [Sorghum bicolor (L.) Möench] productivity, we calibrated the CERES-Sorghum model in the Decision Support System for Agrotechnology Transfer (DSSAT) v4.5 for a sorghum crop grown in the free air CO2 enrichment(FACE) experiment at the University of Arizona, Maricopa, Arizona, USA with a dataset collected during 1998, and validated the model with an independent dataset collected during 1999. During both 1998 and 1999 the simulated grain yield, growth, and water use of sorghum were in agreement [model efficiency (E) = 0.88, E = 0.63, and E = 0.70] with the corresponding measurements, respectively. Neither simulated nor measured yields responded to elevated CO2, but both were sensitive to water supply and temperature. The calibrated (1998) and validated (1999) model was then applied to simulate possible effects of climate change on sorghum grain yield and water use efficiency (WUE) in Western North America for the years 2080-2100. The projected CO2 fertilizer effect on grain yield was dominated by the adverse effect of projected temperature increases, whereas the effect of changes in precipitation on grain yield were negligible. Therefore, temperature appears to be a dominant driver of global climate change influencing future sorghum productivity. These results provide a preview of the potential impacts of global climate change on sorghum grain yield and WUE, which suggest that an increase in water demand for agricultural activities is anticipated in a future high-CO2 world.