Sensitivity of Crop Yield in Iowa to Future Climate Changes

Climate changes in temperature, precipitation and solar radiation, as well as changes in atmospheric CO2 levels are affecting crop yield globally. Climate change is accelerating, as seen in both observations and projections by IPCC reports, and is expected to escalate in the 21st century. Iowa, the second largest exporter of agricultural products, has already seen a significant state-wide increase in average annual precipitation and temperature over the last century and changes are expected to continue into the future as atmospheric CO2 concentration increases. It is not clear quantitatively how climate changes will affect future crop production in Iowa, partly attributed to the likely competing effects between climate changes themselves as well as the CO2 fertilization effect. Decision Support System for Agrotechnology Transfer (DSSAT), a program that includes a suite of crop models allowing for simulation of over 28 types of crops, was used to investigate the effects of the changing climate on corn and soybean yield in Iowa. Both historical and future climate data from climate models as part of the Coupled Model Intercomparison Project Phase 5 (CMIP5) was used as input into DSSAT. Changes in crop yield are shown to be sensitive to the future climate data from each climate model.