PEW: Soil Health Can Combat Climate Change From the Ground Up

About 2,400 acres of a family farm in Watson, Missouri, were still under water a month after spring flooding devastated the Midwest. Soil health practices can help protect farms from erosion and flooding, but they are no cure to some of the devastation farms like this one experienced. – The Pew Charitable Trusts

by: April Simpson| August 23, 2019

Five months after devastating spring flooding across the Midwest, farms along the Missouri River remain under water. This summer, severe drought has hit patches of Texas and Oklahoma. Areas of the West and Southeast are abnormally dry. 

As floods and droughts become more common, farmers, scientists and conservationists are looking for ways to resist. One solution to combating the changing climate starts in the ground. A growing number of states across the country are proposing policies to encourage building healthier agricultural soil, a costly investment for many growers, but one that research shows can benefit farmers and the environment. 

Just this year, at least 10 states have introduced new soil management policies that call for further research or data collection, or offer tax exemptions, technical assistance or even grant money to, among other actions, plant cover crops, diversify crop rotations and reduce tillage that can tear apart beneficial fungi.

Between 2015 and 2018, states debated 166 bills related to soil health, according to an April 2019 report from the Union of Concerned Scientists.

“When soil is healthy, it can hold a lot more water and drain better, but it also can be part of the climate solution,” said Karen Perry Stillerman, a senior analyst with the nonprofit.

Healthy soil can store more carbon; absorb water like a sponge before becoming saturated, making it more resilient in a dry year; and improve water quality by retaining more water, which reduces runoff from cropland. Healthy soil goes further in meeting the needs of a growing population and food production. 

Changing farming practices to promote soil health should be considered a long-term investment, according to many farmers and agriculture experts. However, confusing and restrictive rules regarding crop insurance eligibility also have deterred farmers from adopting practices that can build healthier soil.

According to Stillerman, the taxpayer-subsidized program has favored commodity crops, like corn and wheat, which have been the most damaging to soil health. Historically, farmers who grow organic crops, alternative grains like oats, or diverse mixes of crops have not been supported well by the program, though that is slowly changing, Stillerman said. The 2018 farm bill, for example, adds more flexibility to how cover crops are treated in order to remain eligible for crop insurance.

The program also is likely to get increasingly expensive as climate changes and floods and droughts become more frequent and severe, Stillerman said in an email.

With farm income down, farm bankruptcies up, low commodity prices and an ongoing trade war with China, some farmers struggle to adopt the very practices that could have helped them weather some of the critical obstacles they face. 

“It’s an outlay of cash to begin these practices,” said Ben Steffen, who grows corn, soybeans, wheat and hay in Richardson County, Nebraska, which received federal disaster assistance after the spring flooding. “Given the economic conditions we’re currently in, it’s very difficult to find extra money for those kinds of investments.” 

And for some areas, such as the flood-ravaged Midwest, soil health alone won’t help farmers get out from under water. 

“It’s not going to help you if you have a broken levee that’s dumping water into your field continuously,” said Duane Hovorka, agriculture program director for the Izaak Walton League of America, a conservation organization based in Gaithersburg, Maryland. “There’s no soil cure for that. But where you have excess rain, where you have a wet period, healthier soil will hold more of that water for later.”

Growing Momentum in States

The Union of Concerned Scientists’ analysis seems to highlight a universal interest in soil management, regardless of partisanship, whether policymakers are motivated by climate change or other related environmental challenges.

“I think what’s really important is that there is a lot of attention from a lot of different entry points to, ‘How do we improve soil health?’ ‘How does this help us build resilience on our farms and put farmers in a stronger position to manage the climate and the extreme changes that are happening and are also ahead?’” said Marcia DeLonge, a research director and senior scientist at the group.

In California, for example, then-Gov. Jerry Brown, a Democrat, initiated a comprehensive state strategy in 2015 that resulted in seven state agencies tackling healthy soil on public land, private farms and ranches and in other environmental programs. California had 35 bills introduced during the study period — the most of any state. Among them, 15 have passed, according to the researchers.

Other states, such as New York and Utah, have passed legislation or provided funding to help offset the impact of carbon dioxide emissions. States like Nebraska and New Mexico follow in the footsteps of Maryland, whose soil health program was signed into law in 2017.

“It wasn’t a hard sell to anyone with the concept being a win-win-win for the producer, the consumer and the environment,” said Nebraska state Sen. Tim Gragert, a Republican who sponsored the bill. 

A timeline of soil legislation introduced over the study period shows increasing momentum.

“We’re also hoping that if policymakers see how much momentum there is on the state level, they’ll get something going on the federal level,” said Samantha Eley, a research assistant in the nonprofit’s Food and Environment program. 

A bill sponsored by U.S. Rep. Joe Neguse, a Colorado Democrat, to require the secretary of the Department of Agriculture to direct a study of soil health on federal land was introduced in the House July 30 and referred to the House Committee on Agriculture.

The 2018 farm bill, which President Donald Trump signed in December, includes a Soil Health Demonstration Trial whose participants will follow certain soil health assessment protocols to enable further research and encourage widespread adoption of practices. In addition, the bill includes enhancements to the Conservation Stewardship Program for agricultural producers to improve soil health.

Supporting Farmers

Approaches to improving soil health include expanding the use of fall or winter cover crops, diversifying crop rotations, reducing tillage and using compost, manure, biochar or other soil amendments. Cover crops, for example, increase the amount of carbon dioxide plants take in through photosynthesis. The practice increases soil organic matter and can be more beneficial than leaving land fallow during the fall to early spring period, according to the New York Soil Health Roadmap, an initiative coordinated by Cornell University. Different mixtures work better for farmers depending on their region.

During a heat wave earlier this summer, Gary Lesoing, an educator with the University of Nebraska Extension, visited a farm where the entrance had bare soil between soybean rows. But cover crops also spanned several acres. He took out his soil thermometer to take the land’s temperature 2 inches below the surface. His findings: The land with cover crops measured at 80 degrees, while the air temperature was about 90. The bare soil measured at about 100. 

“You see the benefits of the biology of the soil still working when you have cover crops protecting the soil, whereas if you have bare soil it’s not going to happen,” Lesoing said. “You’re slowing down the biology of the soil on the bare soil and killing some of the soil microbes when unprotected by cover crops.”

Between 2012 and 2017, the United States increased its cover crop acres by 50%, from 10.3 million to 15.4 million, according to the Census of Agriculture. The figure is considered an important indicator of soil health practices. Only a handful of states declined in acreage. 

Soil health, according to the U.S. Department of Agriculture Natural Resources Conservation Service, is the “continued capacity of soil to function as a vital living ecosystem that sustains plants, animals, and humans.” The definition is meant to underscore the importance of managing soil so that it is sustainable for future generations. 

The future is about more than adopting the various soil health approaches, but instead improving systems to get the most benefits from soil health investments, DeLonge said. 

“It’s really about trying to make sure farmers are supported in adopting a system of soil health practices that can help improve the sustainability and resilience of those farms in the long run.”