Drought imprints on crops can reduce yield loss: Nature's insights for food security

Authors: FU, PENG - University Of Illinois; JAISWAL, DEEPAK - University Of Illinois; McGrath, Justin; WANG, SHAOWEN - University Of Illinois; LONG, STEPHEN - University Of Illinois; Bernacchi, Carl

Submitted to: Food and Energy Security
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/1/2021
Publication Date: 2/1/2022
Citation: Fu, P., Jaiswal, D., McGrath, J.M., Wang, S., Long, S.P., Bernacchi, C.J. 2022. Drought imprints on crops can reduce yield loss: Nature's insights for food security. Food and Energy Security. 11(1). Article e332. https://doi.org/10.1002/fes3.332.
DOI: https://doi.org/10.1002/fes3.332

Interpretive Summary: Droughts occur naturally and they have a negative impact on crop growth and yield. However, when exposed to a drought early in their life, plants often develop a resilience to future droughts, a term called 'drought priming'. Thus, exposure to a drought early in growth may have a detrimental impact on crops but may help to protect the same crops from a drought later in the growing season. This study addressed whether this phenomenon can be measure in real-world conditions using satellite imagery, crop reports, and crop modeling. The research showed that naturally occurring drought has a negative impact on crop yields but when two droughts were experiences in one growing season the first drought provided some resilience against the second drought. Global warming is causing wetter springs in the Midwestern US followed by drier mid- to late- summers, suggesting the opportunity for drought priming of crops under rainfed growing conditions may become more susceptible to droughts. However, the evidence that plants are able to become drought-primed suggest that there must be a mechanism to breed for drought-priming in crops without exposure to early-season droughts.

Technical Abstract: The Midwestern ‘Corn-Belt’ in the United States is the most productive agricultural region on the planet despite being dominantly rainfed. In this region, global climate change is driving precipitation patterns toward wetter springs and drier mid- to late-summers, a trend that is likely to intensify in the future. The lack of precipitation can lead to water limitations in crops that ultimately impact growth and yields. Young plants exposed to water stress will often invest more resources into their root systems, possibly priming the crop for any subsequent mid- or late-season drought. The trend toward wetter springs, however, suggest that opportunities for crop priming may lessen in the future. Here, we test the hypothesis that early season dry conditions lead to drought priming in field-grown crops and this response will protect crops against growth and yield losses from late-season droughts. This hypothesis was tested for the two major Midwestern crop, maize and soybean, using high-resolution daily weather data, satellite-derived phenological metrics, field yield data, and ecosystem-scale model (APSIM) simulations. The results from this study showed that priming mitigated yield losses from a late season drought of up to 4.0% and 7.0% for maize and soybean compared with unprimed crops experiencing a late season drought. These results suggest that if the trend toward wet springs with drier summers continue, the relative impact of droughts on crop productivity are likely to worsen. Alternatively, identifying opportunities to breed or genetically modify pre-primed crop species may provide improved resilience to future climate change.