What doesn’t kill you makes you stronger: Research shows crops have drought ‘memory’ to help reduce yield loss

"What we have seen is if the crop survives an early drought, because of that experience they perform better when a drought occurs very close to harvest," said Peng Fu, a postdoctoral researcher at Illinois. "We think the crop responds to the drought and adapts to it, so when it happens again the crops have already planned for the drought and the impact is lessened."

Unlike other drought or climate change research that takes place in a highly controlled environment, this behavior has been observed in corn and soybean fields across Illinois, Indiana, and Iowa. This allows the researchers to look at how crops develop an ability to plan for extreme temperatures and drought, conditions that are only expected to increase in coming years due to climate change.

"Our motivation here is based on the climate change reports and projections we have seen from different agencies that say the Midwest is seeing record heat," said Fu, a member of the Realizing Increased Photosynthetic Efficiency (RIPE) project team who conducted the research. "Since it will continue to happen, we need to develop crop cultivars that can cope with these extreme climates to ensure food security in the U.S. Midwest. Understanding how much climate change could impact crop yield is very important."

RIPE, which is led by Illinois, is engineering crops to be more productive by improving photosynthesis, the natural process all plants use to convert sunlight into energy and yields. RIPE is supported by the Bill & Melinda Gates Foundation, Foundation for Food & Agriculture Research, and U.K. Foreign, Commonwealth & Development Office.

In a recent study published in Food and Energy Security, Fu and his colleagues analyzed almost 20 years of crop yield data and found that corn and soybean plants that had been primed with early-season drought conditions were able to mitigate losses from a late-season drought up to seven percent. Identifying the drought-priming in the plants was a challenge for the group. Even if a priming signal existed, it would be extremely subtle compared to the other factors, including weather, that determine crop yield. To combat this, the team used geospatial and remote sensing data to analyze the crop growth over time and the various weather factors. They also used the Agricultural Productions Systems sIMulator (APSIM) to model different outcomes based on various parameters.

"These results suggest that future climate trends toward wetter springs and drier summers could worsen crop production," said Carl Bernacchi, RIPE leader and scientist with the U.S. Department of Agriculture, Agricultural Research Service, who is based at Illinois' Carl R. Woese Institute for Genomic Biology. "However, the evidence that crops can use an early drought to 'prepare' for a later drought suggests that opportunities might exist to achieve a similar outcome through breeding."

The potential to breed a similar response into plants based on this foundational knowledge is the next step for this research project. Fu, Bernacchi, and their team will work with other RIPE researchers to develop drought-resistant crops in order to help production cope with the changing climate.