This is a complex question centering on the concept of drawdown.
Presently, the oceans have sequestered many gigatons of human-produced carbon caused by burning fossil fuels. Some of this carbon reacts with water to form carbonic acid, turning the ocean’s PH from slightly alkaline to neutral or slightly acidic, killing corals and damaging shell-making ability of ocean-dwelling animals.
The earth’s forests, including boreal forests in northern latitudes and rainforests near the equator, also have sequestered carbon for thousands of years. The destruction of these forests squanders this sink and releases the stored carbon back into the atmosphere.
For drawdown to be effective, both these sinks must be restored.
Additionally, pasture and cropland, managed parts of the food system which feeds 8 billion people, can sequester carbon. The clearest way to think about this is to recognize that organic matter is 58% carbon. Cover crops, management intensive grazing, reduced tillage, and working with soil biology increase organic matter over time in a measurable way.
For people who eat, the benefits are obvious: food raised without pesticides and herbicides is safer and more nutritious.
Organic food is safer because choosing organics lessens exposure to harmful chemicals, including those which mimic estrogenic hormones, those which upset the human microbiome and thus the human brain, and those which are known carcinogens.
Organic food is more nutritious because plants raised organically compete in a complex environment for their nutrition, and in turn are more nutritious themselves when eaten, reversing a decades-long decline in fruit and vegetable vitamins and minerals.
Organics are better for the planet as well. Even with mechanical tillage, organic use of compost, manure and cover crops stabilizes soil carbon at greater depths than chemical no-till. Also, importantly, the soil is alive, with billions of microbes respirating, competing for nutrients, cooperating to feed plant and tree roots, maintaining a complex living system. This is in contrast to a human-induced dead system, with plant and animal nutrition a byproduct of fossil fuel production through the Haber Bosch process and chemical manufacturing. At Mt. Folly, we are conscious of keeping a closed system as we farm. Rather than mirroring industrial agriculture, and trucking in “organic” inputs, we are intent on raising our own fertility with cattle, cover crops, wood chips and manure. While we do “truck in” liquid kelp and organic molasses, we keep purchased organic fertilizer and soil amendments to a minimum.
At Mt. Folly, we rotationally graze our cattle, mimicking buffalo, and have been doing this for decades. Because of the beeves manure and sharp hooves, this practice builds organic matter in pasture soils. We also graze the cattle on the cover crops planted on crop ground.
According to Gabe Brown, Allan Savory, and our own data, animals are crucial for building soil carbon. Mimicking bison and other ungulates, cattle become part of the food web. Their herding instinct, coupled with their manure and group trampling tendency, improve the soil, allowing it to return to its original place in the ecologic system — a carbon sink.
Next, after the cash crop is harvested, we plant cover crops on all crop land, achieving the goal of having the soil covered year-round. In addition to their complex root system, with mycorrhizal fungi and other soil microbes feeding the soil biology, the cash crop plants followed by cover crop plants all photosynthesize, turning atmospheric carbon into food and nourishing the soil’s biology. This system returns oxygen to the atmosphere.
Thirdly, we reduce or eliminate tillage wherever we can. As organic farmers, this is the most challenging task for climate and stable soil carbon.
Finally, we plant trees on the farm’s steep hillsides, making up about a quarter of the farm’s acreage. Our mixed species timber stands are managed with input from a professional forester, so that trees are kept growing, sequestering carbon as they grow.
There are lots of them, so let’s take them one at a time:
1. Cover crops. Photosynthesis is nature’s most brilliant invention. Growing plants pull carbon from the atmosphere, and active soil biology (no chemicals to kill the mycorrhizae and earth worms!) can stabilize and store it there. Cover crops are crops seeded after the cash crop (In Mt. Folly’s case hemp, corn, soybeans, heritage corn, small grains, vegetables and corn silage) is harvested. These start growing in the fall and stay green all winter. Thus, our crop fields are photosynthesizing year-round, and the roots of the plants are active in the very alive soil.
In the spring, as the cover crops are growing, we turn cattle in to eat and poop.
This adds organic fertilizer, and, because the cattle are ruminants who use bacteria to digest cellulose (grass, ensiled corn and hay) in their 8-compartment stomachs, each cow pie is a motherlode of biology plopped on the ground. Then, worms and dung beetles start dragging the poop below the surface to feed the biology there.
2. Minimizing tillage. On organic ground, this is the most difficult, as weed control is necessarily mechanical. We’ve been growing enormous covers, with lots of biomass and nutrients, and have been harrowing them in before planting. Until the 2021 season, our efforts to minimize tillage have included a flame weeder, which we use on organic corn, but not organic soybeans, and a hemp hawk, a precision tillage tool, which hasn’t worked well on anything. We also have multiple targeted tillage tools, as do most organic farms.
Our new roller crimper, which was built by the company which helped with the design and manufacture for Rodale, arrived to late in the 2020 season to be of use. But already (as of October 10, 2020) we are planting cover crop rye thickly, which we will roll down late spring 2021, when the rye begins shedding pollen.
On non-gmo ground, minimizing tillage is pretty easy, as these fields have been no-till for years. We have a good no-till planter, the seeding mechanism of which slices the soil, inserts the seed, and then pulls the soil and cover back over the seed, moves on several inches, and does this again.
Regenerative agriculture is a term used by Robert Rodale to describe a type of farming that went beyond “sustainable,” that made the land and ecosystem better. When put in practice, regenerative agriculture allows the land to heal itself.
Laura Freeman, shown here sharing the cover of a 1992 edition of Rodale’s “The New Farm” magazine with pastured hogs, points out that back then it was called “regenerative,” but now the term has become recognized.
“You can see that New Farm, which we all read as a sacred text, was called, “The Magazine of Regenerative Agriculture,” says Laura. “I was happy to play second fiddle to grazing hogs, and we grazed hogs ourselves, though they kept getting loose and scaring my riding horses.”
Back in the 1970s and 1980s, back-to-the-landers understood that the goal was to mimic biological processes and achieve closed nutrient loops, Laura explains. But farmers were figuring out how to do this and stay afloat. “We still are,” she says.
“You can see from the picture here that we were going to local restaurants, picking up their food waste, and feeding it to pigs…with our great Pyrenees guard dog joining the feast,” Laura says. “I guess you can call this a ‘closed nutrient loop’, and we still feed or compost food waste from our farm to table restaurant and distillery. It was disorganized, experimental, and had great energy. I’m so thankful that some of what we odd-ball farmers were trying to do really can help save the world.”
From a climate change perspective, regenerative agriculture practices can turn farming from a bad thing to a very good thing. Simply put, the suite of regenerative practices can sequester carbon in soils and plants. Rodale ‘s carbon math demonstrates that global adoption of this method could sequester all the carbon humans emit annually. Called “Drawdown,” Paul Hawken and his researchers rank regenerative farming as #11 in a list of 100 promising solutions to the climate catastrophe. The Drawdown math published by Hawken in 2017 computes the practices could reduce carbon pollution by 23.15 gigatons by 2051. This number is based on the speed and breath of farmstead adoption, which Hawken et al estimate is at 108 million acres now. Their goal is 1 billion acres by 2050.