Climate change on track to hit US Corn Belt very hard, study finds

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Climate change will make the US Corn Belt unsuitable for growing corn by 2100 without major technological advances in agricultural practices, an Emory University study finds.

Environmental Research Letter published research, which adds to the evidence that significant agricultural adaptation will be necessary and inevitable in the Central and Eastern United States. It’s critical that these adaptations include diversification beyond the key commodity crops that now make up the bulk of US agriculture, said Emily Burchfield, study author and assistant professor in Emory’s Department of Environmental Science.

“Climate change is happening, and it will continue to shift the geography of U.S. cultivation northward,” Burchfield said. “It’s not enough to rely on technological innovation to save the day. Now is the time to envision major changes in what and how we grow our food to create more sustainable and resilient forms of agriculture.”

Burchfield’s research combines spatial-temporal social and environmental data to understand the future of food security in the United States, including the consequences of climate change.

More than two-thirds of the land in the US mainland is currently devoted to growing food, fuel, or fiber. And about 80 percent of this agricultural land is planted with only five crop commodities: Corn, soybeans, wheat, straw, and alfalfa.

Previous research based on biophysical data has determined that climate change will adversely affect crop yields. For the current paper, Burchfield wants to investigate the potential impacts of climate change on cultivation geography.

He focuses on six major US crops that cover 80 percent of farmland in the United States: Alfalfa, corn, cotton, hay, soybeans, and wheat. He draws on historical land use data classifying where this crop is grown and publicly available data from the US Department of Agriculture, US Geographical Survey, WorldClim Project, World Harmonized Soil Database and other public sources.

Using this data, he built a model to predict where each crop had been planted for 20 years, from 2008 to 2019. He first ran the model using only climate and soil data. These models accurately estimate—between 85 and 95 percent—where these major crops are currently cultivated.

Burchfield ran a second set of models that included human intervention indicators—such as input use and crop insurance—that alter biophysical conditions to support cultivation. These models outperform and highlight ways in which agricultural interventions expand and strengthen aquaculture geographies supported only by climate and soil.

Burchfield then uses this historical model to project a biophysically driven aquaculture shift to 2100 under low, medium, and high emission scenarios. The results show that even under a moderate emission scenario, the geography of maize, soybean, alfalfa, and wheat cultivation will all shift strongly northward, with the Corn Belt in the upper Midwest becoming unsuitable for maize cultivation by 2100. A more severe emission scenario exacerbates change. this.

“This projection may be pessimistic because it doesn’t take into account all the ways technology can help farmers adapt and meet challenges,” Burchfield admits. He noted that major investments were already being made to study genetic modification of maize and soybean crops to help them adapt to climate change.

“But relying on technology alone is a very risky way to approach the problem,” Burchfield added. “If we continue to push for biophysical realities, we will eventually achieve ecological collapse.”

He stressed the need for the US agricultural system to diversify beyond major commodity crops, most of which are processed into animal feed.

“One of the basic laws of ecology is that the more diverse an ecosystem is, the more resilient it is,” says Burchfield. “Landscapes covered by a single crop are fragile and fragile landscapes. And there is also growing evidence that more diverse agricultural landscapes are more productive.”

The US agricultural system incentivizes “monoculture” of a handful of commodity crops, mostly through crop insurance and government subsidies. This system is very detrimental to the environment, says Burchfield, while also supporting the meat-heavy US diet that is not conducive to human health.

“We need to move away from intensive cultivation incentives of five or six crops to support farmers’ ability to experiment and adopt plants that work best in their particular landscape,” he said. “It is important to start thinking about how to move away from the current destructive monoculture paradigm towards systems that are environmentally friendly, economically viable for farmers and climate savvy.”

Burchfield plans to extend the modeling in the current paper by integrating interviews with agricultural policy experts, agricultural extension workers and farmers. “I especially wanted to better understand what different farmers in different parts of the country envision for their operations over the long term, and any barriers they feel are preventing them from getting there,” he said.

Multiple land cover boosts major US crop yields, study finds

Further information:
Emily K Burchfield, Shifting cultivation geography in the Central and Eastern US, Environmental Research Letter (2022). DOI: 10.1088/1748-9326/ac6c3d

Provided by Emory University

Quote: Climate change on track to hit the US Corn Belt very hard, study findings (2022, May 24) retrieved May 24, 2022 from

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