Regenerative agriculture, soil carbon sequestration
Cover crops have been growing in popularity in recent years as a method of improving soil health, saving money, and both adapting to and mitigating the effects of climate change.
Government programs and private carbon credit programs are supporting farmers in planting cover crops after harvesting their cash crops, instead of leaving fields fallow. Many farmers find this saves them money in the form of reduced pesticide use, provides better soil for their cash crops and makes their fields resilient to extreme flooding.
Linus Rothermich has been farming mostly corn and soy in central Missouri’s Callaway County since the 1980s, but in recent years, heavy rains and bouts of extreme weather forced him to think differently about how to make his 900-acre farm more efficient. So, in an effort to address the worsening soil erosion that was damaging his fields, Rothermich started experimenting with no-till agriculture and cover crops. He planted a diverse mix of cover crops like rye and winter hairy vetch immediately after harvesting his main crops, allowing the cover crops to grow in fields that normally would be plowed up and then left fallow.
The results over just a few years have been amazing, Rothermich reports. Runoff and soil erosion have reduced drastically as the cover crops absorbed more moisture and held the soil in place. He soon noticed spots on his farm where the soil had improved markedly. Last summer, an agronomist who inspected his fields told him that based on his inspection of dozens of farms, he has the best soil in central Missouri. “That kind of made me sit up and go, ‘Okay, we’re making a difference,’” Rothermich says.
Experts say Rothermich’s experience is similar to that of many farmers in the Show Me State, with cover crops quickly gaining traction as a way to reduce runoff of farm chemicals and improve soil health. Research shows that cover crops deter weeds, control pests, increase biodiversity in the fields and bolster the ability of soil to absorb water, allowing farmers to reduce the amounts of pesticides and fertilizers they must purchase and apply to their crops.
That’s a helpful incentive for farmers who are squeezed by increasing fuel costs and extreme weather events. The amount of agricultural land employing cover crops has jumped 50% in a five-year period in the U.S., according to the 2017 Census of Agriculture report, as farmers realized the benefits of no-till and cover crop methods — which were popular with previous farming generations — and took advantage of government programs supporting this transition. Cover crops are also both an adaptation to climate change, and a way of slowing it — or mitigating its effects.
Rob Myers, director of the Center for Regenerative Agriculture at the University of Missouri, is right in the middle of this resurgence. The new center is working with government agencies, nonprofits and corporate partners to develop training programs for farmers across the state to increase the use of cover crops and sustainable agriculture technologies. Myers says there are currently about a million acres of farmland in Missouri under cover crop management, a number that he and other U.S. Department of Agriculture experts believe will expand substantially.
“That’s why it’s a win-win, because you’re both mitigating the climate issues by putting the carbon in the soil, and you’re helping farmers adapt to the climate issues by building the life of the soil.”
As a regional director of extension programs for the USDA’s Sustainable Agriculture Research and Education Program, Myers has long been a proponent of no-till methods and cover crop management. He grew up on a family farm in central Illinois, where his father used cover crops before farmers transitioned to chemical-based row crop practices that became popular after World War II. But farming practices are changing again, and climate change is a big part of that.
“When you put carbon in the soil, you’ve also created soil that can deal with these climate extremes,” Myers says. “And it can also help keep the soil in place so that the nutrients aren’t washing out of the fields and getting into the Gulf of Mexico. That’s why it’s a win-win, because you’re both mitigating the climate issues by putting the carbon in the soil, and you’re helping farmers adapt to the climate issues by building the life of the soil.”
While adapting to cover crop practices can include upfront costs and time, the federal government is expanding its efforts to support the use of cover crops for its crop insurance programs. Studies show cover crops improve soil health and reduce claims filed by farmers due to extreme weather events. “As more farms use climate-friendly technologies, we will have fewer claims,” says the Natural Resource Defense Council’s Lara Bryant, deputy director for water and agriculture programs. “There’s a high level of interest in this at the state and federal levels.”
Even more important to farmers, research shows that cover crops can increase yields and cut costs. “Cover crops have also been shown to increase crop yields, break through a plow pan [a layer of compressed soil that is difficult for plant roots to grow through], add organic matter to the soil, prevent leaching of nutrients and attract pollinators,” say experts with the Sustainable Agriculture Research and Education program. “There is a growing body of evidence that shows cover crops improve resilience in the face of erratic and increasingly intensive rainfall, as well as under drought conditions. Cover crops help when it doesn’t rain, they help when it rains, and they help when it pours!”
The science of soil carbon sequestration is still evolving, but there is growing evidence that sustainable agriculture techniques can greatly increase the amount of carbon dioxide pulled from the atmosphere, thus reducing the impacts of climate change. Research shows that cover crops in the U.S. have the potential to sequester 60 million metric tons of CO2 a year. Based on the country’s current 20 million acres of cover crops, an area about the size of South Carolina, cover crops offset the emissions of nearly 13 million passenger vehicles.
The corporate world has taken note of this potential market too. One of the corporate partners Myers and his program is working with is Bayer’s new Carbon Initiative. Bayer, the third-largest agricultural products company in the world after its acquisition of Monsanto in 2018, is now promoting the use of cover crops combined with carbon credits to entice farmers in the U.S. and Brazil to switch to more sustainable farming practices. The expanding Carbon Initiative pays farmers for the conversion to no-till agriculture and the use of cover crops. Bayer then uses the carbon credits for its own emissions reduction programs or sells the carbon credits on a global carbon market exchange.
Meanwhile, other companies are joining the agriculture carbon market world. Indigo is one of the most aggressive new companies entering the field, raising venture capital money and selling carbon credits to corporate buyers like North Face, JPMorgan Chase and Barclays. The companies then finance farmers to switch to sustainable agriculture techniques such as cover crops. The company has enrolled farmers with more than 2 million acres so far, and company representatives say Missouri farms along the Mississippi River and the Corn Belt are prime areas for participation.
“It’s a game changer, getting farmers to use better farming practices,” says Ryan Stockwell, an agronomy strategy manager for Indigo who also farms in Wisconsin and is familiar with farming practices in Missouri. Stockwell says cover crops improve soil health, reduce the impacts of climate change by removing more CO2 from the air, and help increase farmers’ bottom lines by making their farms more productive and offering new streams of income through the evolving carbon credit market.
But not all farmers need to be enticed to use cover crops by getting paid through carbon credit programs. Macauley Kincaid is a 27-year-old farmer in Jasper, Missouri, who five years ago was struggling to grow corn, soybeans and wheat. After doing his own research and talking to sustainable farming experts, Kincaid decided to try a different approach, using a variety of cover crops and rotating cattle through his fields to increase natural fertilizer. Kincaid says his soil erosion levels have dropped, his crop yields have improved, and his farm fertilizer and chemical costs have been cut dramatically. Despondent about his future a few years ago, the young farmer now is optimistic. He eagerly talks to other regenerative farmers around the country, taking calls from whoever is interested in his success.
“I’m trying to build this farm for my children,” Kincaid says. “I am farming for future generations.”
Story by: Rocky Kistner (July 2021)
Image: Mac Kincaid has seen vast improvements on his farm since he started using cover crops. | Credit: Mac Kincaid.