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Farmland Can Sequester Carbon From the Atmosphere


Truck being loaded with compost at the Stemple Creek Ranch in Tomales, California, which is participating in a decade-long trial carbon farming program.

California rancher John Wick says the Marin Carbon Project could help save the world from climate change.

“How would you possibly know, looking out at this beautiful day in front of us, that the Earth is crashing?" he asks, rhetorically. "But when scientists measure it and see the effect of it, and watch the ocean die-off and everything happening, this is scary as hell. And, then, we have evidence that there might be something that could stop that. And, then, we had measurement of something that holds promise to actually reverse it.”

That "something" is carbon farming, using processed compost to cool the Earth. It's a theory developed by rangeland ecologist Jeff Creque, who also promotes beneficial land management practices to increase the health of agricultural systems.

“Agriculture is the art of moving carbon dioxide from the atmosphere to the vegetation to the soil and, then, back again," he says, explaining, "If we can increase the rate of carbon capture and decrease the rate of carbon loss, we can actually begin to bend that Keeling curve of carbon dioxide in the atmosphere in the other direction, which is what we need to achieve.”

Wick met the ecologist when he turned to him for help restoring his ranchland, which had been overgrazed by cattle, and overrun with invasive weeds and brush. After implementing a strategic grazing disruption plan Creque designed, deep-rooted native flora gradually returned to the property.

The plan for the original research block to test compost’s carbon retention potential on John Wick’s Nicasio Native Grass Ranch.
The plan for the original research block to test compost’s carbon retention potential on John Wick’s Nicasio Native Grass Ranch.

Wick was now a firm believer in Creque's theories, and to prove them, they founded the Marin Carbon Project. In December, 2008, they covered a carbon-depleted test plot on Wick's land with one and a quarter centimeters of processed compost, next to another grazed test plot without compost. They wanted to see if the compost-treated land would pull carbon dioxide out of the atmosphere and sequester durable carbon during photosynthesis.

Good for the soil, air and water

Compost, Wick explains, is like medicine for poor soils, "and when you put this compost on top of soil – not tilling it in – but just setting it on top – good things happen and that’s what our research showed.”

Creque says, as time went on, more good things happened.

"What we saw every year was that it happened again and again and again. Each year. Without any additional compost," he said. "So a one-time application of this high-carbon soil amendment had resulted in an increase in plant productivity that yielded a full ton of additional carbon [captured] per hectare. And that continued and continued. That annual on-going increase, the model suggests, will continue for 30 to 40 to 50 years or more."

Jeffrey Creque (L) examines MCP Demonstration Ranch partner Loren Poncia’s (R) compost at the Stemple Creek Ranch prior to application.
Jeffrey Creque (L) examines MCP Demonstration Ranch partner Loren Poncia’s (R) compost at the Stemple Creek Ranch prior to application.

The benefits were well beyond expectations.

"When you put that across 10 million acres of crop land, we’re talking enormous quantities of carbon dioxide absorbed from the atmosphere and sequestered in the soil. Beneficially sequestered in the soil. Not just tucked away doing nothing, but, rather, actively supporting the capacity of those soils to produce crops and to hold onto water," Creque said. "So, the water implications of this, particularly for a state like California, but really across the American west and much of the arid regions of the world, increasing soil organic matter. What little bit of rain we do get, allows us to hang on to that and make better use of it.”

Wick is thrilled with the results of the Marin Carbon Project’s experiments and believes carbon farming could make a big difference if it was widely implemented.

"The implications of this globally are that we can actually cool planet earth, should increase production of food and fiber, fuel and flora in a way that actually enhances resources," he said. "So the more you do, the more you can do. It is the most exciting thing ever."

John Wick talks about carbon farming to a group of students at his ranch, the Nicasio Native Grass Ranch.
John Wick talks about carbon farming to a group of students at his ranch, the Nicasio Native Grass Ranch.

Not so fast!

But other voices are more tempered. Tom Hedt, a resource conservationist for the Natural Resources Conservation Service, agrees that compost helps capture carbon in the soil and takes some CO2 out of the air. But it's just one of a host of land management practices that NRCS encourages to help the soil and the air. Others include crop cover, reduced tillage, and tree and hedge plantings.

Hedt notes that every plot is unique, and more research needs to be done to fully determine the effectiveness of carbon farming and whether the Marin Carbon Project's findings hold up on a large scale.

"[Carbon farming] is an emerging issue," he said. "There are some people that are very excited about it. [But] there are dangers of taking a few plots and just doing the math. Multiplication is pretty easy, but the site-by-site prescriptions are much more complicated than that."

He says MCP'S data shows enough promise that last year, 14 four-year field trials were initiated on various range and grasslands throughout California to test the use of compost for beneficial carbon farming on different terrains.

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