Net benefits to US soy and maize yields from intensifying hourly rainfall

Abstract

Many varieties of short-duration extreme weather pose a threat to global crop production, food security and farmer livelihoods1–4. Hourly exposure to extreme heat has been identified as detrimental to crop yields1,5; however, the influence of hourly rainfall intensity and extremes on yields remains unknown4,6,7. Here, we show that while maize and soy yields in the United States are severely damaged by the rarest hourly rainfall extremes (≥50 mm hr−1), they benefit from heavy rainfall up to 20 mm hr−1, roughly the heaviest downpour of the year on average. We also find that yields decrease in response to drizzle (0.1–1 mm hr−1), revealing a complex pattern of yield sensitivity across the range of hourly intensities. We project that crop yields will benefit by ~1–3% on average due to projected future rainfall intensification under climate warming8,9, slightly offsetting the larger expected yield declines from excess heat, with the benefits of more heavy rainfall hours outweighing the damages due to additional extremes. Our results challenge the view that an increasing frequency of high-intensity rainfall events poses an unequivocal risk to crop yields2,7,10 and provide insights that may guide adaptive crop management and improve crop models. Short-term extreme weather events such as hourly heat can negatively impact crop yields. US maize and soy yields are damaged by rare extreme hourly downpours, but benefit from more common heavy rainfall, indicating yields may benefit from increasing precipitation intensity under climate change.