According to the 2017 Census of Agriculture, nearly 600,000 acres of cover crops were planted in Pennsylvania. In Illinois, only 160,000 acres of cover crops out of the state’s 22 million acres of corn and soybeans are planted in cover crops.

“If you paved Chicago in cover crops, that’s how many cover crops get grown every year” in Illinois, said Adam Davis, head of the crop sciences department at the University of Illinois.

But he’s looking to change that, especially if future predictions on climate change and the impacts on farming start coming true. Speaking at the Northeast Cover Crop Conference in Portland, Maine, Davis said farmers in his state are already seeing the effects of climate change, from earlier field working days to hotter and drier summers.

He sees cover crops and more diversified cropping systems as keys to mitigate the effects of climate change and ensure farms are resilient.

The past eight years have been the hottest on record, according to data from the New York Times that he presented. In places such as Illinois, the Upper Midwest and the Northeast, Davis said that winters are warming quicker than any other season on average. The number of extreme precipitation events is also increasing, he said.

From 1958 to 2012, the Northeast saw a 71% increase in amount of precipitation falling in the form of “very heavy events,” according to EPA data Davis presented. The agency also predicts that under a “high emissions” scenario, the average temperature in the Northeast could increase between 2 and 4 degrees F a year between 2041 and 2070.

“You’re getting reduced seasonality here in the Northeast,” he said. “And reduced seasonality is hitting hardest around this region.”

Farm challenges

Longer growing seasons might sound good to some, especially if you’re thinking of putting in double-cropping systems or like to get your ground planted earlier. But it’s the number of field working days that really matter, Davis said, and those could be fewer as the climate changes.

In a 2017 research project done by Davis and his research group — it was authored by Brad Tomasek, a master’s candidate at the time — they created a physical model of soil working days based on soil types and amount of rainfall.

LATE PLANTING: This photo taken June 2, 2019, illustrates the difficulties farmers in Illinois had getting into their fields that year. The weather was cool and wet, and the only active plants on the landscape were small woodlots, some pasture areas and winter annual weeds. To Adam Davis, this photo says a lot about the opportunities farmers lose when they focus only on summer cash crops. (Photo by Adam Davis)

They then went back and trained the model using eight decades of fieldwork data in Illinois, and then added climate change scenarios based on characteristics determined by the Intergovernmental Panel on Climate Change (IPCC). They then worked in a few climate change scenarios to see potential effects of changing conditions on field working days.

The typical pattern in Illinois is a wet early spring, followed by midsummer drought through mid-August. In each scenario that was evaluated, the early spring wet pattern did not change. It projected that late March planting could become commonplace as winters get shorter.

But each scenario also predicted that midsummer droughts would get longer and more severe by the end of the century. This will leave growers with potentially less field working days to get crops in the ground before the long, hot summer arrives.

With millions of acres needing to get planted in shorter time, this could create some big challenges.

“One of the things that we have here, we got increased working days very early, and then we’ve got drought pressure later on,” Davis said. “We’re going to have to think about how we shift our relative maturity dates of our crop hybrids to work with this. We’re going to have to think about how we might take advantage of that late-winter, early-spring period … and cover crops are a type of crop that could be taking advantage of that window.”

Diversifying fields

A challenge to getting cover crops planted, though, is the time needed to get the crop planted and growing in fall.

“One of the things that hinders adoption of cover cropping in the I states is, it’s a pain in the neck,” Davis said.

A project done by the STRIPS Project of Iowa State University looked at planting prairie strips to diversify corn and soybean fields, planted at the Neal Smith Wildlife Refuge in Jasper County, Iowa. These prairie strips were planted between strips of corn and soybeans.

The goal, Davis said, was to see if the strips could have a similar effect as a cover crop — mainly reducing nutrient and sediment loss — while at the same time taking minimal acres out of corn and soybeans, and not reducing crop yields.

COVER STRIPS: A project done by the STRIPS Project of Iowa State University looked at planting prairie strips to diversify corn and soybean fields, planted at the Neal Smith Wildlife Refuge in Jasper County, Iowa. These prairie strips were planted between strips of corn and soybeans. (Photo courtesy of Richard Cruse)

Researchers found that between 2007 and 2014 on fields that had about 10% incorporated prairie, those fields saw a 44% reduction in water runoff, 95% reduction in soil loss, 90% reduction in phosphorus runoff and 84% reduction in nitrogen runoff, all while seeing no big reduction in per-acre yields.

In fields that are flood-prone or are just not as profitable, prairie strips could be a viable option for growers who want the benefits of a more diversified cropping system.

“There is room for continuous living cover in parts of fields that are not profitable,” Davis said.

More technology

Current methods of planting cover crops early include interseeding into a growing crop or flying on cover crop seeds, but each of these has its advantages and challenges.

For example, a high-clearance cover crop seeder, or highboy, can get the seed in, but the challenge is ensuring there is enough moisture in the ground for the cover crop to get established and growing.

Earthsense, located in Champaign, Ill., has developed ultracompact autonomous robots that are designed to go into fields in swarms to plant cover crops and rake in the seed right under the corn canopy. Farmers don’t need to buy these robots. Instead, Earthsense provides it as a service.

Another potential technology, Davis said, is a biodegradable cover crop seed coating that keeps the cover crop dormant until it is time for the crop to emerge. He said the idea is that a grower would plant the cover crop with their cash crop. The coating would initiate the cover crop seed to go dormant until conditions are right for it to emerge.

Davis said this is future technology that is years away from becoming commercially available.

In the meantime, Davis hopes growers will be convinced to make changes that could make their farms more resilient to a changing environment.

“None of these climate resilience things can work if we don’t have adoption,” he said.