As one result of modern farming practices that strip organic matter from the ground, between 20 and 60% of the carbon once stored in the world’s agricultural soils has been lost. Putting it back – a process known as carbon farming or regenerative agriculture – has been hailed as a promising climate mitigation solution.
According to Rattan Lal, PhD, a leading expert on soil carbon, agricultural land could capture the equivalent of around 20% of annual global emissions. But Lal stresses that the benefits of carbon-rich soil go beyond climate – it’s also vital for food security, water quality, and biodiversity. Failure to replenish soil carbon is not an option, he said. “It’s not either/or. It’s a must.””Failure Click To Tweet
He believes that paying farmers to sequester carbon – specifically, about $16 per acre per year – is an important part of the solution. Some payment programs have been tried in the past, he said, but they haven’t been effective enough. “I do not think there is a real payment-of-ecosystem-services program anywhere in the world.”
Soil as a bank
Lal uses a personal finance analogy to explain soil carbon management. “In your bank account, you want your total asset to increase,” he said. “Soil carbon is exactly the same way. If you put more carbon in soil than you take out, the soil carbon stock will go up and help give you more interest and more other benefits. But if you take out more than you put in, it will go down.”
“Right now, the way the farmers are doing things, we are taking out more than what we put in.”
The causes of carbon loss are well understood, according to Lal. One is erosion from wind and rain. Another is the starvation of soil microorganisms, resulting from a lack of food sources like crop residue and root biomass. Soil disturbance (through tilling or bulldozing, for example) is problematic, as is leaching (in humid climates).
These losses can be minimized through a set of practices known as conservation agriculture, which emphasizes minimizing soil disturbance, keeping the soil covered, and rotating crops. But only about 8% of cropland is farmed this way, Lal said.
The problem isn’t that farmers don’t understand soil carbon, he believes. “Farmers are not stupid. I think they are very wise. They are wiser than the scientists, because they have to make their living out of this system.”
Instead, the issue is money. If farmers can earn more by selling their crop residue for hay or other uses than by leaving it on their fields, many will, he said. “And simply by me or you going in and telling them ‘Don’t you dare do that!’ will just make them laugh and tell you, ‘Get lost,’” he said. “And that is exactly what we are doing.”
Carbon storage payments
Proposals to make carbon sequestration financially attractive to farmers are becoming more common. Over the past few months, Democratic presidential hopefuls including Pete Buttigieg, Elizabeth Warren, and Bernie Sanders have pledged to pay for carbon farming if elected. Former candidate Cory Booker introduced a Senate climate change bill that would increase funding for a U.S. Department of Agriculture program that provides financial assistance to growers who adopt sustainable practices.
At the state level, California’s Healthy Soils Program Incentives Program currently offers grants to help producers store carbon. In Montana, conservation-focused nonprofit Western Sustainability Exchange runs a carbon payment program for ranchers.
Startups are also getting into the game, betting that private-sector companies can help pay farmers by selling carbon offsets.
One trillion tons?
Last summer, Boston-based Indigo Agriculture made headlines in business media with the announcement of its Terraton Initiative, which aims to pay growers to sequester one trillion tons of carbon dioxide.
Although Indigo is involved in a range of farm-related activities, from microbial seed treatments to agronomy (expert farm consulting, essentially) and crop transportation, soil carbon is a major focus. The company has promised that farmers who signed up for its carbon program before the end of 2019 will receive at least $15 per metric ton sequestered. Payments will be financed partly through the sale of offsets, which go for $20 per ton. As of late January, growers had committed more than 17 million acres to the program, according to Indigo’s website.
Ed Smith, who leads the company’s carbon program, says that recent technological advances and increased public demand for climate solutions will help the Terraton Initiative succeed where others have failed. “We think now is the moment. We think now is different,” he said. Improvements in satellite technology allow Indigo to monitor farming practices like cover crop usage and tillage from afar, while distributed ledger technology enables secure public information-sharing for carbon credits.
Technology is also helping Indigo reduce the high cost of soil carbon measurement. “Measurement has basically killed the economics of projects in the past,” Smith said. To avoid the need for resource-intensive testing at every site, Indigo is gathering data from selected fields, then using it to calibrate a digital model that helps predict carbon sequestration rates in other locations.
To help bolster the accuracy and credibility of soil carbon measurement, Indigo has also formed partnerships with two carbon standards bodies, Verra and Climate Action Reserve.
Incentives and barriers
Another startup that wants to pay growers for carbon farming is Seattle-based Nori. Its recently launched online marketplace connects people who want to fund sequestration to those who can provide the service – farmers, for example. According to the company, a recent pre-sale moved enough carbon credits to pay Maryland farmer Trey Hill more than $80,000, enough to capture 5,340 metric tons.
While individuals can use the marketplace to offset their own emissions, large companies that work with growers have also expressed interest in Nori’s model, said Chief Development Officer Christophe Jospe. “They have frustration internally. They say, ‘We know what needs to be done. We know the best practices and we know how to help our farmers. We just need a system that they can plug into so that we can reward the farmers for the best practices.’”
But Jospe cautioned that the agricultural sector is complex, and that ecosystem service payments are only one piece of the solution. Powerful economic, political, and social forces steer many U.S. farmers toward practices that emit carbon rather than capture it. Crop insurance is weighted toward large-scale commodity production, and trusted salespeople tout the benefits of business-as-usual seeds, fertilizers, and equipment. Consolidation destroys midsize farms. Social pressures can discourage “doing weird farming,” as Jospe put it.
Many farmers are also justifiably wary of outsiders, Jospe said, having been hurt in the past by policy and business decisions over which they had little say. “I think there’s a lack of trust that farmers have that is well deserved, because they’ve been found on the short end of the stick time and time again,” he said.
On the other hand, financial self-interest could help attract more farmers to regenerative agriculture. Many growers who have adopted these practices say that their profits have increased over time. According to Jospe, some of those who are now most active in carbon circles moved away from conventional agriculture simply because the chemicals it requires became too expensive. “A lot of the farmers have basically said, ‘Well, I can’t survive in this way anymore. Where can I reduce my fertilizer, pesticides, herbicides?’, and have found that those practices correlate really nicely with improving soil health. And that increases soil carbon,” he said.
But regenerative agriculture is still a niche practice. To help as many growers as possible understand how soil carbon sequestration can help them, Nori works with groups that have strong relationships within the agricultural community: The Nature Conservancy and farm software Granular, for instance, as well as agronomists.
“Farming moves at the speed of trust,” Jospe said. “So we’re not necessarily trying to get this right by being a group that sits down at every individual table – rather, let’s just plug into the networks where the relationships already exist.”
Sarah Wesseler is a Brooklyn-based writer focusing on cities, culture, and climate change.