As many know, the main greenhouse gas contributing to climate change is carbon dioxide. (No, carbon isn’t the only factor –– climate change is complex and intersects with regenerative agriculture in many ways –– but it’s a big one.)
Yet, while most people focus on the carbon that’s released from burning fossil fuels, we now know that soil contains large amounts of carbon as well. And when that soil is disturbed by tilling, much of the carbon is released into our atmosphere.
That’s where regenerative agriculture has a vital role to play in fighting climate change.
One of the chief aims of regenerative is reducing the carbon dioxide released from soil. While not as visible as what’s spewed into the air through exhaust pipes or smoke stacks, researchers have discovered that our soils contain significant carbon deposits of their own.
Project Drawdown estimates that industrial activity is responsible for 21% of total greenhouse gas emissions. In a separate report, they find that food, agriculture, and land use are responsible for 24% –– an even bigger impact!
But researchers have also got encouraging news:
Soil can be managed in ways that reduce the release of carbon.
In April of 2022, a study titled Soil carbon sequestration through regenerative agriculture in the U.S. state of Vermont was published in PLOS Climate. The researchers –– University of Vermont postdoctoral researcher Serge Wiltshire and professor Brian Beckage –– set out to study how different ways of managing Vermont farmland could lower atmospheric carbon.
According to Wiltshire, a lot of the carbon that has been released into Earth’s atmosphere began underground, and got out when the soil was disturbed. As he said in a UVM press release describing the study, “the only viable way to reduce atmospheric carbon is to store it back in the ground, where it started.” Furthermore, in Wiltshire’s view, “tweaking farmland management is probably the easiest and most effective of the currently understood strategies” for sequestering carbon in soil.
For their study, Wilshire and Beckage started by gathering actual climate, soil, and land use data for farmland in thirteen different “ecoregions” of Vermont. Then they consulted experts and research literature to determine the likely effects that different ways of managing the soil would have on soil carbon. Finally, they fed everything they learned into computer simulations that calculated how much carbon each land management strategy would keep in the soil over a number of years.
Every single regenerative soil management practice kept more carbon in the soil.
And out of the earth’s atmosphere.
Wiltshire and Beckage referred to these practices as “non-business-as-usual scenarios.”
One such practice is cover cropping, which is when plants are planted to cover the soil instead of for harvesting. When done properly, cover cropping reduces soil erosion, improves soil fertility, and promotes biodiversity.
Another is crop rotation, which is when farmers grow a series of different crops in one area over several growing seasons. (Instead of growing the same crop in the same place indefinitely.) This reduces the reliance on one set of soil nutrients, and the likelihood of resistant pests and weeds.
Wiltshire and Beckage also simulated the impact of rotational grazing: moving livestock to different portions of pasture while the pasture they were just on gets to rest. This allows the pasture as a whole to better-resist soil erosion. Which, in turn, sequesters more carbon.
Of all the regenerative agriculture scenarios that were studied, rotational grazing “offered the highest soil carbon sequestration potential.” And all of the scenarios were shown to sequester more carbon than “business as usual”, or non-regenerative management of the land. (The researchers also found that converting all agricultural land to old growth forest would sequester the most carbon of all –– while conceding that, of course, this is unlikely to happen.)
The widespread adoption of regenerative practices like rotational grazing won’t solve climate change by itself (or overnight.) But the potential for steady carbon reduction is clear and promising. Keep in mind that Vermont (where this study was conducted) is only 12% made up of farmland.
In midwest states with more farmland, the application of these practices could yield exponentially higher climate change benefits. In any case, studies like these plainly demonstrate the power and potential of regenerative land management to reduce carbon emissions over the long-term. And remember, this is just the beginning: climate change has many implications for regenerative agriculture that we’ll talk about in future posts.
Learn more about how Vayda measures climate outcomes here.