Carbon trading – and the carbon credits that make it possible – is almost here. And when it is, we all stand to benefit: farmers, consumers, businesses, our soil, and our planet. But do you wonder what all this sequestered carbon actually does for the soil? And is carbon trading really a solution for taking carbon out of the atmosphere?
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Over the holiday break, my family was lucky enough to escape Omicron and go to the Virgin Islands. Some of us went diving a few times. On our various dives, we saw a wreck from 1867, colorful coral fish, barracuda, a shark, and even an octopus.
Afterward, as we sat on the beach with cold drinks, we enjoyed looking at the crystal blue water and the sailboats bobbing up and down. I thought to myself, if you didn’t spend time underwater, you would never understand what was beneath the seemingly benign surface.
The same can be said for soil.
As you drive or fly over the countryside, you’ll see picturesque farms and beautiful landscapes. And underneath, there is a dynamic, ever-changing microbial environment that affects our health and the Earth’s environment. The world of soil that supports everything green – including 95% of our food– is just as hidden as the abandoned ships and fish beneath the waves.
And just like ocean life, soil is critical to our future. Healthy soil has a tremendous benefit besides growing our food: it efficiently stores carbon, cleans our water, and give us the nutrients we need in our food.
Saving the soil for future generations
As a civilization, we have degraded our soils up to 10 times the rate of rebuilding. Since we have been farming the prairies, the Nature Conservatory reports that the U.S. has lost about 60% of its original organic carbon content in the soil. In the days of the buffalo, the United States had 18 inches in topsoil; today, on average, there is around eight inches. Future generations are facing climate change, nutrition security, and soil degradation.
Yet all is not lost. It is ironic that as we search for a climate change solution, we also urgently need to save our soil. The challenge today is to produce more food for more people with less land under plow with degraded soils, using less water and fewer energy resources. Soil carbon sequestration seems to be an answer for both.
In a previous D2D post, we addressed trading carbon credits between those who emit carbon and those who sequester carbon. According to Carbon Credit Capital, a company that matches carbon emissions with carbon capture programs, the average American emits about 20 tons of carbon each year, equivalent to driving 48,000 miles in a car. To find your carbon emissions, the EPA has a household carbon footprint calculator.
As a solution to climate change, farmers and ranchers are encouraged to measure the carbon they are pulling out of the air and storing in the ground as they grow their crops. They can sell this carbon in the form of a carbon credit.
In a quick search online, I found a couple of examples, one being Truterra, a farmer-driven sustainability platform. They work with farmers to evaluate carbon sequestering practices and match those who believe in the power of ‘farm-to-form’ and are looking to buy carbon credits. Indigo Ag contracts carbon agreements with farmers and identifies buyers to sell credits.
We wondered: What does all this additional carbon do to the soil?
Carbon’s critical role with soil
Carbon is present in every living thing – and it has helped the Earth thrive for the past 3.5 billion years. Plants and trees need CO2.
Someone once told me that our food system is just the commercialization of photosynthesis. Plants absorb sunlight, carbon dioxide (CO2), and water (H2O) to create their own energy.
Plants release the oxygen back into the air (luckily for us, as we need it to breathe). The water absorbed by leaves acts as a transport system to bring carbon down through the leaves to the roots and then into the soil.
Looking underneath the surface, you need a microscope to see the diversity of life. There are more organisms in a single teaspoon of healthy soil than people on our planet!
Soil is full of minerals, organic material, living organisms, gas, and water. One could call it the Earth’s brain, teeming with algae, fungi, nematodes, and bacteria that all merge together to give the plants nutrients.
CO2 is the nutrient that gets pulled down through the roots – a liquid carbon pathway. Plants convert this to sugars which feed the microbiome. The more food the plant provides to the microbiome, the more prolific the root system.
Plants and their microbiome have a symbiotic partnership that enables both to thrive. The plants feed the microbes in the soil. In return, the microbes in the soil feed the plants, much as our gut hosts the individual variety of microbiomes that give us antibodies to fight illness.
Each plant hosts their unique microbial community that surrounds its roots. This is called the rhizosphere – an area looking much like an old-fashioned hairnet, holding 100 times more microbes than in the surrounding soil. It is one of the most biodiverse and dynamic habitats on earth!
Part of the rhizosphere’s community is the mycorrhizal fungi. They increase the amount of space in the soil where the plant can take up nutrients and water.
Carbon as plant food
The more carbon a plant has, the more carbon it pulls out of the air. Carbon helps feed the microbes that keep plants healthy. Basically, the plants ‘pour’ carbon in the form of carbohydrate-rich exudates into the rhizosphere and the surrounding community of mycorrhizal fungi.
Plants and mycorrhizal fungi have had a relationship for 475 million years, working together to influence the Earth’s biosphere.
This partnership can reduce CO2 levels by 90%.
The higher the chlorophyll content in the leaf, the higher the rate of photosynthesis, the more carbon pulled out of the air, and the more mycorrhizal fungi. And so the cycle continues.
The plants then feed the beneficial microbes. The exude is a blend of amino acids, vitamins, and phytochemicals. The microbes hungrily consume this cocktail of nutrients. In return, these microbes protect and defend the plant from pathogens wanting to take them down.
As David Montgomery and Anne Bikle so eloquently explain in their book, The Hidden Half of Nature:
“Plants can’t run or hide but they have defensive strategies such as botanical swords (thorns) and shields (waxy leaf cuticles). Microbial recruits do the job below ground, taking on the role of palace guards to protect their botanical ally. Imagine a plant’s root system as a castle in an underground landscape harboring microbial bandits and invaders.
In this way, plants use carbohydrates (and other compounds) that only they can make to attract and build a community of microbial bodyguards that displace, deter, or take our microbial enemies.”
Did you know the carbon in soil enables plants and trees to communicate with each other? As we learned, carbon increases the microbial community. The mycorrhizal fungi can move through the soil and deliver phosphorus to areas of scarcity, letting fungi receive carbon.
This allows plants to have their own secret language through 100 different chemical signals among the microbes in the rhizosphere. They warn each other about pests and fungi so they can put up a protective defense.
What type of farming best suits carbon sequestration?
In part, sequestering carbon is why regenerative agriculture has shown such success to both the plants and the soil. Certainly, pulling carbon out of the air and into the soil is the most efficient way to sequester carbon.
But another entry point for carbon to make its way into the soil is through no-till agriculture. By not turning over the soil with a plow, the organic material remains on the surface, protects the soil from blowing away, and helps it to absorb water. As it decays into the ground, it produces carbon as a nutrient for the soil.
Regenerative agriculture also includes planting cover crops to keep the soil safely covered from erosion and to maintain a living root system in the soil to provide adequate carbon nutrition levels for the hungry microbial communities. Farmers also rotate their crops each year which increases plant and microbial diversity in the soil.
Gabe Brown, a prominent regenerative farmer from North Dakota has increased the carbon and the yield on his farm. You can see the carbon increase as he layered in cover crops, diverse crops, and livestock.
This brings to mind what Dave Albert, from Misty Mountain Farms, said when he drives by his neighbor’s farms, “You can tell a farm has unhealthy soil when there is a lot of mud on the road after a rain — a sign that the soil quality has deteriorated so much that it simply just washes away.”
The agricultural system is a marvel – and the future of our society.
Solving the riddle of climate change – and defining the role of healthy soil in that solution – won’t come about by the efforts of any single government agency, global company, or the efforts of just one person. All have a role to play, certainly. But a solution will come about through a collaborative and cooperative effort across every part of our modern food chain.
How can we help?
The farmer is the foundation for that work. The people who are farming today are on the front lines in combating climate and nutritional deficiencies in the soil. What is done on the farm or ranch to enrich soil (and to protect our air and water) make up the building blocks of the solution. Farming and the ag community are both a positive influence to improve global warming, as well as ensure nutrition for our plants and us.
Your part in helping farmers capitalize on their carbon sequestration is to look at carbon credits to help offset your carbon emissions. McKinsey estimates that in 2020, buyers retired carbon credits for about 95 million tons of CO2. By 2030, they predict the annual demand could go up to 1.5 to 2.0 gigatons of carbon. Or, put another way, the market could be between $20-50 billion.
This is one more situation where we can unite around food. Governments, businesses, and consumers can encourage the efforts made by farmers by rewarding responsible soil-health practices. It is both individual efforts and collaborative achievement that gives us the most modern and efficient food system in history. We got there as a united country.
The Bottom Line
Healthy soil is the most critical environmental element in a growing population. Carbon farming will be the answer to both removing carbon from the atmosphere and increasing our soil health. It is not what you see that is so important to our life; it is what you cannot see that has the most impact. Just like diving underwater, there is an entire world beneath the soil that scientists are just beginning to understand.