Do shallow water tables contribute to high and stable maize yields in the US Corn Belt?

Shallow water tables (WT) can buffer against transitory rain-free periods leading to higher and more stable yields in rainfed crops. However, little is known about their influence on regional crop production and its stability. In the present study, we assessed the impact of WT on maize production in the US Corn Belt. Analysis of historical yields and modeling revealed that WT may explain higher than expected yields. At regional level, WT led to higher (6%) and more stable maize production compared with the scenario without WT, especially in years with severe drought (24% production increase). Results highlight the need to account for WT for yield forecasting and for studies investigating the influence of current and future climate on crop production.