Big corporations like Microsoft and General Mills, famous philanthropists like Leonardo DiCaprio, and governments large and small are spending millions of dollars on dirt. They’re investing in the future by staking out acres of storage units for carbon, to be captured for safekeeping in the topsoil of farms across the land, through soil carbon sequestration.
When a plow breaks ground, it causes carbon-containing molecules in the soil to mix with atmospheric oxygen, creating carbon dioxide, the damaging greenhouse gas. Over time, agriculture has racked up quite the bill when it comes to carbon emissions. Recent estimates indicate that since the Industrial Revolution, 133 billion tons of carbon have been lost from the soil, accounting for one-fourth of all carbon that humans have released into the atmosphere. That’s not to mention what technology has introduced, with fuel for tractors, transportation and fertilizer production adding up to over 10 percent of greenhouse emissions. Carbon smart farming offsets this large and growing debt, to slow the planet’s warming, through no-till practices and cover crops.
Cover crops are most often a mix of cereals, legumes, or other vegetables grown not to harvest, but to give the soil a break, enriching it with nutrients, locking in the carbon-rich matter, and preventing erosion. Between 2012 and 2017, the practice of planting cover crops increased 50 percent nationwide. Ahead of the curve, the State of Maryland began paying farmers to grow cover crops nearly thirty years ago, in efforts to reduce pollution in Chesapeake Bay. Trey Hill, a farmer on Maryland’s Eastern Shore, was a skeptical early adopter. “It had nothing to do with climate or soil health,” Hill says. “All of us thought it was a bunch of environmental BS… Then we found that it works and saw that the soil started to change.” Hill observed that where he grew cover crops, the soil eroded less and held more water. Carbon smart farming has paid off for Hill. In addition to mitigating surface erosion and runoff, the practice aids in nitrogen fixation, provides food for pollinating insects, and brings Hill an additional $100,000 a year.
In Ohio, long-time no-till farmer and champion of climate-smart practices, Fred Yoder testified before the House Select Committee on the Climate Crisis, urging lawmakers to support a carbon market that would incentivize farmers to both reduce carbon emissions and restore topsoil health in danger after years of industrial farming. “Here in Ohio, we are back on our heels because of nutrient movement, and we could kill two birds with one stone with climate policy as well as nutrient policy.”
According to the USDA, no-till farming, originally adopted in the 1940s in response to the disastrous Dust Bowl, is now practiced on more than a third of U.S. cropland, with another third classified as “low-till.”
The Rodale Institute has warned that we have only 60 years of adequate topsoil remaining. Elizabeth Whitlow, executive director of the Regenerative Organic Alliance, a California-based nonprofit formed by the Rodale Institute, Dr. Bronner’s and Patagonia Inc., explains: “By eating food grown in dead soils, we’ve eliminated many of the nutrients our bodies need to live and robbed the soil of essential organic carbon. By reversing that cycle, we can increase the soil’s ability to hold water, improve soil structure, and enhance microbial activity that helps make nutrients available to plant roots.”
In March, Minneapolis-based General Mills committed to use regenerative practices on 1 million acres of farmland. Jerry Lynch, the company’s vice president and chief sustainability officer, said General Mills wants to engage in climate protection to the planet’s benefit, but also to avoid a future of overworked, environmentally depleted farmland that’s no longer able to produce food.
Soil scientist Rattan Lal, of Ohio State University, estimates that regenerative farming practices could draw two-thirds of the carbon we’ve lost from the soil back underground, significantly decreasing atmospheric carbon dioxide. A 2018 report by the National Academies of Sciences, Engineering, and Medicine found that soil sequestration could remove up to 250 metric tons or more of carbon dioxide per year in the United States alone, heralding it as a cost-effective and readily available climate solution.
Proponents of “natural climate solutions” like soil carbon sequestration emphasize the importance of soil, water and climate health to agricultural enterprise. During the 20th century, the United States’ success as a global agricultural power was measured by how much food was grown in American soil. In the 21st century, we are working with a new paradigm — how much carbon can we keep in the soil while still growing food? The jury is out, but the modus operandi is on the table.