Contrasting Impacts of Dry versus Humid Heat on U.S. Corn and Soybean Yields

The impact of extreme heat on crop yields is an increasingly pressing issue given anthropogenic climate warming. However, some of the physical mechanisms involved in these impacts remain unclear, impeding adaptation-relevant insight and reliable projections of future climate impacts on crops. In a new study published in Scientific Reports, a team of researchers including NE CASC coauthors Corey Lesk and Radley Horton examine historical climate and crop data over the United States to illuminate the impact of extreme dry heat  and extreme humid air on agricultural output.

Ultimately, the study reveals that extreme dry heat steeply reduced U.S. corn and soy yields, but extreme heat accompanied by humid air, in contrast, had insignificant yield impacts and even boosted productivity in some areas.  Since few prior analyses have considered the role of humidity in crop yields, the results of this study suggest that the scientific community may have underestimated crop sensitivity to combinations of high temperature and very dry air.  Furthermore, crop yield projections that fail to consider the amount of moisture in the air--and how that might change in the future--are likely to be inaccurate. Future work will consider the implications of our crop findings for more natural vegetation.