Researchers at Michigan State University in East Lansing have concluded that, despite a warming climate that may lead to more severe droughts, the crops in the Midwest may not need more water in the future.
“Warmer temperatures generally mean that crops need more water, but that doesn’t seem to be the case in the Midwest,” says Bruno Basso, an ecosystems scientist and MSU Foundation professor in the Department of Earth and Environmental Sciences within the College of Natural Science and a faculty member at MSU’s W.K. Kellogg Biological Station and AgBioResearch.
“Because the increase in average temperature comes from higher minimum temperatures — the temperature at which dew is formed — this means that the air is also becoming more humid.”
The researchers say changes in soil management may help crops adapt to changes in air temperatures and moisture.
“The Midwest supplies 30 percent of the world’s corn and soybeans,” says Basso “These crops are sensitive to temperature and water changes.”
Previous studies have suggested that by 2050, the Midwest will need about 35 percent more water to sustain its current levels of corn and soybean yield. Basso and colleagues, however, found data that does not support this idea. The Midwest typically receives ample rainfall and has deep soil, ideal for farming.
Basso and his team analyzed climate trends from weather stations from across the Midwest dating as far back as 1894 and found that average daily temperatures during the summer have increased throughout much of the Midwest. They also discovered that daily minimum air temperatures, usually during the nighttime, have increased, while the daily maximum daytime temperatures have decreased.
The trends hold true during the full, 120-year weather record studied or during more 30- to 60-year time periods.
According to Joe Ritchie, distinguished emeritus professor at MSU and a researcher for the project, the two contrasting trends have canceled each other out. So far, the potential crop water demand has remained relatively unchanged despite the warming climate.
Data were entered into computer simulation models developed at MSU by Basso and Ritchie to gauge the impact of these trends continuing into 2050. Rafael Martinez-Feria, another lab member, says that in the worst-case scenario, the amount of water needed by crops could increase by an average of 2.5 percent. More conservative estimates indicate that water needs would remain practically the same because summer rainfall would also increase.
Basso says that although crop water needs may be similar in the future, increasing air temperatures could also make droughts more likely to occur.
“The impact climate change will have on the Midwest is still uncertain,” he says. “We are still at risk of droughts.”
Instead of installing extensive and expansive irrigation systems that might only pay off in the event of extreme droughts, Bassos advises farmers to invest in technology and regenerative soil practices that make plants more resilient and adaptable to climate change.
“As we continue to learn more about weather and its increased variability, farmers need to adapt, which they are starting to do,” Basso says. “I feel optimistic that with the progress made in regenerative practices, genetics, and digital technology solutions, we can adapt to climate and have a better chance of winning this battle against our own previous mistakes.”
The research was published on March 5 in Nature Communications. It is available here.
