Carbon storage offers hope for climate, cash for farmers
Farming techniques that are good for the soil may also play an important role in fighting climate change
May 21, 2021, 5:00 AM
7 min read
Farmer Rick Clifton drives a spray tractor across one of his fields, applying herbicide to cover crops that occupied the ground during fall and winter in Orient, Ohio, on April 5, 2021. Clifton grows cereal rye and rapeseed to prevent erosion and make the ground healthier for his corn, soybean and wheat cash crops. Cover crops store carbon in the soil, keeping the greenhouse gas out of the atmosphere. (AP Photo/John Flesher)
ORIENT, Ohio -- The rye and rapeseed that Rick Clifton cultivated in central Ohio were coming along nicely — until his tractor rumbled over the flat, fertile landscape, spraying it with herbicides.
These crops weren't meant to be eaten, but to occupy the ground between Clifton's soybean harvest last fall and this spring's planting. Yet thanks to their environmental value, he'll still make money from them.
Farmers increasingly have been growing offseason cereals and grasses to prevent erosion and improve soil. Now, they're gaining currency as weapons against climate change.
Experts believe keeping ground covered year-round rather than bare in winter is among practices that could reduce emissions of planet-warming gases while boosting the agricultural economy, if used far more widely.
“For too long, we’ve failed to use the most important word when it comes to meeting the climate crisis: jobs, jobs, jobs,” President Joe Biden said in his April address to Congress. One example, he added: “Farmers planting cover crops so they can reduce the carbon dioxide in the air and get paid for doing it.”
Clifton, 66, started growing cover crops several years ago to improve corn, soybean and wheat yields. Then he read about Indigo Agriculture, a company that helps businesses and organizations buy credits for carbon bottled up in farm fields. He signed a contract that could pay about $175,000 over five years for storing greenhouse gases across his 3,000 acres (1,214 hectares).
“If you can get something green on the ground year-round, you're feeding the microbes in the soil and it's a lot healthier,” he said, touring a barn loaded with cultivating and harvesting equipment. “And if somebody wants to pay you to do that, it looks to me like you're foolish not to do it.”
Agriculture generates about 10% of U.S. greenhouse gas emissions: methane from livestock, nitrous oxide from fertilizers, carbon dioxide from machinery.
All industries are under pressure to reduce emissions, primarily by switching to renewable energy.
But farming has something most others don't: the ability to pull carbon dioxide, the most prevalent climate-warming gas, out of the atmosphere and store it. Plants use it in photosynthesis, their process of making food.
Besides cover crops, promising techniques for carbon storage include reducing or eliminating tillage and letting marginal croplands revert to plains or woods, said Adam Chambers, a U.S. Natural Resources Conservation Service air quality scientist.
Agriculture won't be “the sole solution, but I see it as a solid plank in an overall program to address climate change over the next few decades,” said David Montgomery, a University of Washington geologist.
The National Academy of Sciences estimates agricultural soils could take in 250 million metric tons (276 million tons) of atmospheric carbon dioxide annually, which would offset 5% of U.S. emissions.
Some caution against overselling farmland's potential. Iowa State University ecologist Steven Hall says that at some soil depths, microbes convert carbon absorbed by cover crops into gas that returns to the atmosphere.
“It may make sense to pay farmers to do this,” he said. “But I would go into it a bit more suspicious that we'll get a maximum performance on all farms.”
The federal government has spent hundreds of millions of dollars helping farmers make environmentally friendly changes. Since 2005, those actions have produced an eight-fold increase in prevention of greenhouse gas emissions, the NRCS says.
