Effects of water surplus on prevented planting in the US Corn Belt for corn and soybeans

Abstract

Record-high prevented planting of staple crops such as corn and soybeans in the United States (US) Corn Belt due to heavy rainfall in recent years has spurred concern over crop production, as growing evidence suggests winter and spring precipitation extremes will occur more frequentlyin the coming decades. Using county-level data, we examine the effects of planting-season water surplus—precipitation minus evaporative demand—on prevented planting of corn and soybeans in the US Corn Belt. Using monthly water surplus data, we show significant impacts of excess moisture on preventing planting and suggest a 58%–177% increase in prevented planting during the months of April–June per standard deviation increase in water surplus. Downscaled climate change projections are used to estimate future changes in prevented planting during the mid-century (2036–2065) under the moderate emission scenario (RCP4.5). Our model predicts a decrease in prevented planting of approximately 111,000 acres (12%) for corn and 80,000 acres (16%) for soybeans in the US Corn Belt, relative to historical levels from 1950 to 2005. However, if we consider only precipitation and disregard evaporative demand, the alternative model indicates an increase of approximately 260,000 acres (30%) for corn and 86,000 acres (19%) for soybeans. Geographically, we find that prevented planting will slightly increase in some parts of Iowa, Minnesota, and Wisconsin and generally decrease in the other parts of the US Corn Belt. This work collectively highlights the value of incorporating water surplus data in assessing prevented-planting impacts and is the first known study to examine changing risk of prevented planting under future climate scenarios that may help inform adaptation efforts to avoid losses.