Response of Soybean to Predicted Climate Change in the USA

Abstract

Soybean [Glycine max (L.) Merr.] is a major crop in the USA in terms of production, exports, and area of land used in its production. Projected changes in climate could have major impacts on the production of this crop as well as on areas where it would be produced. A simulation study was conducted to characterize these possible effects using a soybean crop growth model, historical weather data, and three possible climate change scenarios based on global climate model (GCM) results. For each weather scenario, rainfed and irrigation management cases were studied under normal and elevated atmospheric CO{sub 2} levels. Results showed that the high annual variability of rainfed soybean yields under historical weather conditions was amplified by the GCM-based climate change scenarios. The negative effects of climate change alone on soybean yields were mostly offset by the increased atmospheric CO{sub 2} concentration for two of the scenarios for both irrigated and rainfed cases. The third scenario resulted in decreased yields in most locations. On average, the climate change scenarios resulted in a 60% increase in estimated water requirements for irrigation. These results suggest that soybean production in the USA would not be adversely affected by climate change if themore » climate changes according to two of the GCMs, unless water supply for irrigation is limited. Under the most severe climate change scenario, however, soybean production in the USA could be reduced considerably unless changes in production regions and practices are made. 31 refs., 11 figs., 6 tabs.« less