Climate change could harm corn

A study found that corn yields could drop by as much as 50 percent by 2050.

by David Clarey

Climate change may threaten future corn yields in the Midwest, a new University of Minnesota study shows. 

Using predictive models based on historical data, the study, which was released late last month, looked at the state of Iowa and found that projected temperature increases and sporadic moisture levels could cause corn yields to drop anywhere from 15 to 50 percent by 2050.  

“We’re getting the same challenges we always have, but we’re either getting them more frequently or more intensely,” said Tracy Twine, an associate professor in the Univeristy’s department of soil, water and climate and one of the study’s authors. 

In Minnesota, more than 8 million acres of corn are harvested annually, a 2015 report from the U.S. Department of Agriculture shows. Corn brings in 45 percent of the state’s $14.6 billion total profit from crop production, according to the Minnesota Department of Agriculture.

Twine said the study looked at USDA data on crop yields, soil data and climate observations and used six different models to predict climate change’s possible effects on corn yields in Iowa. 

The study also imagined a scenario where moisture levels were kept at optimal points, for which their models predicted a loss of 10 to 20 percent, Twine said.

The models did not account for changes in farming techniques and human impact on the climate, something Twine said is critical to understand.

“We’re just trying to show what kind of yield changes you would get if you kept doing things the same,” she said. “I don’t think anyone needs to worry because they certainly have been working on breeding more heat-resistant cultivars constantly.”

Chris Novak, CEO of the National Corn Grower’s Association, said most farmers may not view climate change as a pressing matter. 

“I would say it’s not a significant concern [to farmers] yet, but only from the standpoint of wanting more information and a better understanding,” he said. “I think some of our farmers are still looking and saying, ‘OK, what does climate change mean for me on the farm?’”

Novak said that the association has several programs researching the relationship between agriculture and climate change and that studies like Twine’s study helps farmers understand the issue.

“It’s just one step further in creating an understanding and finding a need for farmers to be engaged in managing this issue,” he said.

Lori Abendroth, who helps lead USDA’s Sustainable Corn team, said because farmers already deal with yearly differences in weather, they may be well equipped for the possible challenges of climate change. 

She said her team focuses on developing strategies that famers can implement to help corn combat climate change.

“When we look at climate change, we primarily look at what are the impacts of increased weather variability,” Abendroth said.

Abendroth said her team has looked at various techniques for farmers to help protect their crops, including using cover crops, diversifying crops and trying different tilling strategies.

“The main thing is, ‘How do we take into account the complexity of agricultural systems in the face of changing climate, and also the goals that farmers and consumers have for improved sustainability?’” she said.