Can Irrigation Mitigate Drought Impacts on Crop Yields in Deep South?

Abstract:

Curtailment of water uptake during critical stages of rainfed crops can severely reduce crop yields during droughts. Although irrigation is widely accepted as a climate change adaptation strategy to combat crop failure, it is unknown how much crop yield loss can be avoided by irrigation during droughts, specifically in the Deep Southern states where rainfed agricultural practice is dominant. Here, we consider Mobile River Basin (MRB) in the Deep South as a case study, and propose a novel framework of integrating an irrigation water requirement model and a spatial crop yield simulation model to simulate corn and soybean yields during four drought years at three different irrigation water application rates (50, 75 and 100% of irrigation water requirement). Our results show corn and soybean yields can be increased from 12% to 258% and 23% to 226%, respectively, compared to the rainfed yields during drought years. The irrigation water source and the associated costs are important to be considered, however, in this study we did not evaluate these variables. Our findings emphasize that irrigation can be a crucial management strategy and should be implemented by the farmers of Deep South to combat crop yield reduction, in particular during droughts.