Testing for adaptation in the observed corn and soy yields in the US Midwest

The positive effects of warm temperatures on crop yields reverses beyond a critical temperature threshold, where sharp decrease in yields is observed for all crops. In the light of warming trends observed globally, adaptation of crops to extreme climatic conditions could be crucial for ensuring a stable food supply in the future. While numerous studies have shown the potential positive impact of adaptation on food security, there is limited evidence showing observed changes in the sensitivity of major food crops to high temperatures at national and global levels. In this study, we use regression models to examine the spatiotemporal variations in critical temperature threshold for corn and soy in the US Midwest. Further, we also examine changes in yield response to exposure to temperatures beyond the critical temperature threshold. Overall, our work tests for the presence of adaptation in the observed yield trends of corn and soy in the US Midwest.