This story was originally published by Modern Farmer and is republished with permission.
Hans Schmitz, an Indiana wheat farmer, made a difficult decision this year. In a last-minute call, he planted only 100 acres of wheat, roughly half the amount of seed he usually grows. The soil just wouldn’t allow for any more.
“We felt it was too dry. And when we did get rain right at the end of the planting window, we had some issues with flooding,” he says.
Instead, Schmitz opted to plant soybeans—a less lucrative crop. “We sacrificed on the scale of 100 bucks an acre.”
Schmitz isn’t the only farmer challenged by a changing climate. So far, however, those challenges have not resulted in lower crop yields. Just the opposite. American farmers are producing more than ever, USDA statistics show.
The United States saw record yields across the board in 2021 at 894 pounds per acre—a 21-percent increase from the year before—according to the USDA. Yields were down slightly from those record figures in 2022, but they were still above average.
Crop production has improved by multiple metrics, says Ariel Ortiz-Bobea, an applied economist who studies the impact of climate change on agriculture at Cornell. “What you really want to know is how all the outputs are growing relative to the inputs [such as water and fertilizer],” he says. “That gives you a measure of how productive you are.”
Even by this measurement, agricultural productivity is on the rise, says Ortiz-Bobea, citing USDA data. Farm output is even outpacing population growth, he says, meaning farmers are still producing more than enough to feed everyone in the United States.
But researchers wonder how long those technologies and innovations can stay ahead of a warming world. A 2021 Cornell study, for example, found that farmers have lost seven years of productivity growth over the last 60 years because of climate change.
Ortiz-Bobea notes climate change decimated cropland in parts of the global south, leading to widespread malnutrition and mass migration, and he hopes the struggles in those regions are not a harbinger of what is to come in the United States as the world grows hotter and dryer.
How does climate change impact crops?
Production has trended upward in recent years, even as drought ravaged the southern sun belt and heavy spring rains overwhelmed midwestern fields. Farmers and experts attribute increased production to advances in agricultural techniques and a better understanding of how crops handle bad weather.
“Farmers have large, high-speed GPS-controlled planters, and they can plant a lot of crops in a short amount of time even though the window to plant might be shorter,” says Fred Below, a crop physiologist and professor at the University of Illinois.
Still, according to Below, “The weather is the number one factor that influences crop yield.”
In some ways, a warming world helps farmers. Warmer weather extended planting seasons by between 10 and 15 days in the Midwest. But the harmful conditions far outweigh any benefits, experts say.
“We’re seeing warmer lows,” says Dennis Todey, director of the USDA Midwest Climate Hub. “Nights are not cooling down as much and that has a different look than if you have warmer daytime highs.” Higher nighttime temperatures stress crops. Soybeans, for example, grow more quickly in warmer conditions, which reduces yields.
“We see warmer temperatures in February and March, and small grains such as winter wheat will grow and enter reproductive stages earlier. Then you get a cold spell in April or May and you can see frost damage because [the plant is] triggered to grow earlier than it should,” says Laura Lindsey, a soybean and small grain agronomist at Ohio State University’s extension service.
But one of the most difficult changes to cope with is rainfall. As the climate changes, spring rains are growing more intense and summers are experiencing more prolonged droughts.
Total rainfall is rising in some parts of the country, but periods of rain are growing fewer and further between—rather than 15 days with two inches or rain, regions such as the midwest might experience 10 days with four inches of rain.
“One of the biggest things we’re seeing in Illinois is an increase in rainfall and rainfall intensity,” says Illinois State Climatologist Trent Ford. “It’s about five inches wetter, which wouldn’t be a big deal if patterned out in the right way. A lot of that is coming in increasing intensity, with really large amounts of rain.”
To make matters worse, soil can only absorb so much water and the excess erodes into nearby rivers and streams, taking expensive fertilizer with it.
“You’re left with a fraction of your fertilizer for the crop,” says Ford.
Agricultural resilience
Experts note that American farmers have an advantage over growers in less developed nations because the United States has a department of agriculture that researches growing conditions and land grant universities in every state, with extension services working directly with farmers. The USDA also offers monetary help such as crop insurance that gives farmers financial assurances.
Crops such as corn and soybeans are also bred to use less water or to grow to a shorter height, making it less vulnerable to the intense winds that come with climate change.
“There are marker-assisted genetics in corn that impart some water use traits,” says Below. “These contain marker-assisted genes that optimize water use.”
However, experts like Ortiz-Bobea warn that the same planting techniques helping farmers adapt now could hurt them in the future if drought proliferates. For example, corn farmers are planting rows of corn closer together to squeeze the highest yield out of limited acres.
In some respects, this strategy works. However, when roots are closer together, competition for scarce water intensifies, making the crop more vulnerable to drought, says Ortiz-Bobea.
How long can technology overtake climate?
Researchers disagree over whether or not the increase in crop yields is sustainable with climate change hovering over the agriculture industry like the sword of Damocles.
“Climate change is not the destroyer of agriculture in Illinois,” says Ford. “The negative impacts are making things a bit more complicated. It’s changing things, and so it really requires a broad perspective of how we’re doing agriculture in the Midwest and maybe we can do it more effectively in the face of these changes.”
However, data shows that a warming planet has made a difference. In a study of crop production last year, researchers at Cornell concluded that yields would be 21% higher over the past 50 years if the weather was consistent from year to year.
And the extreme rain and prolonged drought vexing farmers are only projected to get worse.
“These very bad years are going to become more frequent,” says Ortiz-Bobea.
While some experts are hopeful, no one can say with certainty that advances in science and technology will continue to make up for the increasing frequency of drought and extreme rain.
If the temperature and precipitation continue to change at the pace growers have seen in recent years, a warming world may eventually outpace farmers’ capacity to adapt to it.
