Reduced Crop Yield Stability Is More Likely to Be Associated With Heat Than With Moisture Extremes in the US Midwest

Abstract

Understanding the changes in crop yield stability (μ/σ) under climate change is critical for food security and farmer livelihoods. Unstable crop yields have been identified as detrimental to international food trade and markets. However, the association between climate extremes and crop yield stability has not been well documented. Here, we present the sensitivity of corn and soybean yield stability to heat, drought and excessive wetness by using statistical modeling for rainfed corn and soybean based on survey yield records in the US Midwest. The results using survey data indicate that increased heat, drought and excessive wetness are collectively associated with reduced yield stability for corn and soybean. We find that the changes in corn and soybean yield stability in the US Midwest are predominantly related to heat stress. Additionally, irrigation can mitigate the yield stability reduction associated with heat and drought. In contrast, well-irrigated yield is more sensitive to excess wet. Our results highlight the importance of examining the correlation between climate extremes and crop yield stability.