At the Root of Cover Crops: Carbon Sequestration
When you receive a gift from a loved one, it’s natural to want to give one right back—and, thanks to the bountiful essence of Mother Nature, when you give her a present, she’ll turn around and provide you with even more, creating a beautiful cycle of planting and harvesting.
Although it may be hard to know which of nature’s cycles is most generous, it’s pretty easy to make the case that the one we’ll be describing qualifies:
We plant seeds for vegetables, edible flowers, herbs, microgreens and more.
Through the miracle of photosynthesis, the sun provides nutrition so that these plants can grow, while the water from the planet hydrates them.
We gather in the seasonal fruits of the harvest throughout the year.
People can eat delicious and nutritious meals.
After harvesting, farmers at The Chef’s Garden plant cover crops to build our soil up to a degree that’s even healthier than how we found it, a key way to give back to the Earth.
Via these cover crops, Mother Nature offers up yet another of her gifts through the process of sequestering atmospheric carbon dioxide. This amazing process helps to “offset greenhouse gas emissions, such as the carbon dioxide emitted by cars, power plants and other burning of fossil fuels. The soil has significant potential to store carbon and to mitigate the effects of climate change.”
Is our list an oversimplification of what’s happening? Sure, but it provides an overview of just one of Mother Nature’s most amazing gifts, one that includes a process that hasn’t been discussed much: the sequestering of carbon.
“Carbon sequestration,” Bob Jones, Jr. of The Chef’s Garden recently said, “is a really big topic that’s ripe for more discussion.”
As with any conversation about an important topic, everyone joins in at their own unique levels of knowledge—that’s just how it is. So, in this post, we’ll go through the broad topic of cover crops and carbon sequestration, step by step, and you can read the entire blog post or use the sub-headings to join in at the point that makes the most sense and provides maximum value for you.
No matter where you start in the post, though, we encourage you to read the entire section near the end titled “Regenerative Farming” because it includes newly provided insights from Ron Joyce at Joyce Farms. He made these comments at the Fête des Bouchers held at the Culinary Vegetable Institute on Saturday, October 12, led by the legendary Chef John Folse.
What are Cover Crops?
At its simplest, a cover crop is one that isn’t being grown for the purposes of human or animal consumption. It’s a crop being grown to feed, protect, and enrich the soil. The reality is that soil is its own ecosystem and, the healthier that you can help to make and keep your soil, the more vibrant and alive the soil is—and this helps to foretell how healthy your crops will be.
Examples of cover crops used at The Chef’s Garden include alfalfa, buckwheat, oats, rye, and sorghum—and, at any one time, two thirds of our fields contain cover crops, rather than produce that we sell to chefs and home cooks.
In fields containing cover crops, we plant and then tend the crop for a relatively short time; if oats, for example, the crop grows until the plants are about six to eight inches tall. We then work the crop into the soil itself, which both feeds the soil and controls weeds. We repeat this process as many times as necessary.
As the next step, we lay out beds for the vegetable crops we plan to grow, letting weeds germinate but, before they emerge, we shallowly till the ground, just enough to disturb the hairs of the weeds. If we dig too deeply, we’d only be bringing up more weed seeds. If we waited until we could actually see the weeds emerge, then it’s much more challenging to destroy them.
Handling them at the stage we do, though, allows us to get rid of white root hairs that will then quickly and easily desiccate in the wind. We repeat this process, as needed, and then we’re ready to plant our crops.
This may sound like a lot of steps to take and plenty of physical labor—and, you’re right. It is. But, as Bob, Jr. explains, “This process allows us to have far less competition from weeds. And, even more important for chefs, this is what allows us to eliminate the need for chemicals. Sure, we could do one quick till and then pour chemicals onto the land, but we’re never about minimum standards. We want to produce healthy, nutrient-dense products for chefs without harming the land for future use.”
That bears repeating: We want to produce healthy, nutrient-dense products for chefs without harming the land for future use.
And, when it comes to soil health, here’s what Bob, Jr. adds. “Soil is a living, breathing organism just like we are, and you have to treat it as such. It needs food, air and water to be able to be productive. And, if you really want it to be productive, you’ve got to give it rest. The same things we need.”
Now that we’ve answered the question of “What is a cover crop?” we’ll move on to the next part of the equation: sequestering carbon.
What is Carbon Sequestration?
The Forest Service of the United States Department of Agriculture provides a helpful carbon sequestration description, describing it and its benefits this way: “Carbon sequestration is the process by which atmospheric carbon dioxide is taken up by trees, grasses, and other plants through photosynthesis and stored as carbon in biomass (trunks, branches, foliage, and roots) and soils. The sink of carbon sequestration in forests and wood products helps to offset sources of carbon dioxide to the atmosphere, such as deforestation, forest fires, and fossil fuel emissions . . . while enhancing other ecosystem services, such as improved soil and water quality.”
Traditionally, according to University of California, Davis’s Science and Climate department, 26 percent of carbon emissions were captured by the forests, farms, and grasslands of the Earth. So, scientists in this field of study are trying to find ways to adapt our use of Earth’s landscape to sequester carbon more effectively.
Now, we’ll bring the two concepts together.
Role of Cover Crops in Carbon Sequestration
According to a July 2018 publication by Sustainable Agriculture Research & Education: “Cover crops are an important soil carbon sequestration strategy. The roots and shoots of cover crops feed bacteria, fungi, earthworms and other soil organisms, which increases soil carbon levels over time.”
This publication also shares results from 26 separate research trials, and the following was concluded: that “cover crops have the potential to sequester approximately 60 million metric tons of CO2-equivalent per year when planted across 20 million acres (8.1 hectares), offsetting the emissions from 12.8 million passenger vehicles.”
Meanwhile, in March 2019, the Institute of Agriculture and Natural Resources' Cropwatch by the University of Nebraska-Lincoln provided solid evidence that cover crops are important—not only to the people who eat and consume produce, but for the entire planet. Researchers point out that agricultural soil that has been “intensively managed” has lost 50 to 70 percent of the carbon that existed within before the soil was cultivated, which is contributing to the carbon dioxide in our environment.
So, researchers conclude, “Management practices that capture the atmospheric CO2 and enhance carbon (C) sequestration in the soil are needed . . . Soils are the largest terrestrial reservoir and may provide the best way to remove carbon from the atmosphere. Indeed, agricultural soils are the largest terrestrial carbon reservoir, and therefore represent a large potential sink to store carbon.”
After a four-year study, their conclusion is that “cover crops can . . . improve the ability of soils to store carbon.”
Bob Jones, Jr. shares that this process really is a type of composting. “It’s the flow of energy from the sun to the cover crop, from the cover crop to the soil, and from the soil to the microorganisms, from the organisms to the vegetables. The organisms are feeding off of the root exudates that are a product of photosynthesis, converting soil chemistry to a form that the plant can take back up. We’re putting a diversity of plant organic matter back into the soil to be decomposed by the organisms that are in the soil naturally, as long as you haven’t put something on the soil to kill those.”
As alluded to in Bob’s last statement, chemical pesticides interrupt this natural process, with these applications decimating the underground organisms that the cover crops and other regenerative farming practices are building up. The good news is that, when soil is nurtured through regenerative agricultural techniques, the need for pesticides is already drastically minimized.
Plants grown in a healthy environment, like those at The Chef’s Garden, have strong immune systems, which helps to protect them against disease and insects. In an environment of healthy soil, it’s tough for some of the bad stuff to even take a foothold because of the positive activity that’s busily and successfully competing against them.
Cover Crops and Soil Health
Using cover crops to improve and maintain soil health is, without question, an ongoing process. At the farm, we maximize cover crop effectiveness by:
rotating where they’re planted
consistently and repeatedly planting them
planting a diverse mix of cover crops
harvesting and saving cover crop seeds for successive plantings
Going back three decades or so, we were using rye as our cover crop. Then we realized that the more species included in the cover crop mix, the better—so we now plant four to six species to boost the diversity of the microbiology that’s living off the plants’ roots.
By growing our cover crop seed right here on the farm, we’ve automatically got a supply of seeds that already have a remarkable affinity for the environment.
“When a plant grows in this specific environment, it tends to tune in to its surroundings,” Bob, Jr. said. “So when we harvest the seed from cover crop grown here, and we plant that here again, now you have generation two, generation three, generation six. It is really tuned in to right here. Each generation gets a little bit better. It gets a little healthier.”
Planting superior vegetable seeds into superior soil makes a difference, as well, according to Jones. “You put good genetics in combination with healthy soil, that’s where the magic happens,” he said. “It’s a continual process, and it tends to get better and better and better.”
Here's more about how we continually focus on creating the healthiest soil possible.
More About Regenerative Farming
Planting cover crops is a key element of The Chef Garden’s overall regenerative farming practices that focus on making the soil healthier and even more productive every year.
Most traditional farms don’t go as far as we do. That’s because we’re not trying to go as far as what the average farm might go. Instead, we focus on establishing best practices to be the team that actually sets the regenerative farming bar. We focus on doing what’s right just because it’s the right thing to do.
At our Fête des Bouchers at the Culinary Vegetable Institute this year, Ron Joyce of Joyce Farms discussed his belief—one that we wholeheartedly share—that industrial farming practices have pushed Mother Nature too far.
“Not only have we lost flavor,” Ron said, “but we are really eating products that aren’t as healthy for us, so we use fat, salt and sugar to flavor things.”
At Joyce Farms, they practice regenerative farming practices to grow crops for their poultry, pigs, and cattle—and we appreciate the example he gave of the benefits of these practices. He asked people in the audience to compare a tomato that you can buy at the grocery store to one that we grow at The Chef’s Garden, and he bets that people will clearly notice a “night and day difference” in our favor.
At the Bouchers event, Ron quoted statistics that shared how, at most farms, organic matter in the soil is only about one half of one percent—adding that it should be four percent, or five or six. He also pointed out that most farms can only absorb half an inch of rain per hour. Farms that use regenerative farming techniques, though, can absorb that much water, Ron says, in about four seconds.
“Experts told us,” he adds, “that it takes 100 years to get soil back to that kind of level.” By strongly focusing on regenerative farming practices, though, Joyce Farms was able to accomplish incredible things in just three to four years.
The Chef Garden Philosophy
As Farmer Lee Jones likes to say, you shouldn’t ever try to outsmart Mother Nature because we already know who is going to win. At The Chef’s Garden, we’re growing vegetables slowly and gently in full accord with nature using the regenerative farming techniques being discussed here today.
You can find more information about our regenerative farming philosophy—and, if you’re a chef or home cook who embraces the same beliefs, we invite you to contact us online.