Growing awareness and concern for the environment, changes in government policy, America’s return to the Paris Agreement and high demand for carbon offsets all indicate an appetite for a different type of agricultural crop – carbon.
“There has been growing discussion of how to create a way for farmers to obtain credit for climate-friendly practices that they have implemented or are going to implement in their operations,” said said Joe Outlaw, Ph.D., co-director of the Agriculture and Food Policy Center at Texas A&M College of Agriculture and Life Sciences and economist with the Texas A&M AgriLife Extension Service, Bryan-College Station. “One of these means is the cultivation of carbon which would capture or sequester organic carbon in the soil, which would allow the sale of carbon credits to companies so that they can offset their greenhouse gas emissions. . “
However, many questions about the carbon efficiency of agriculture and its value to the farmer remain unanswered. Will there be incentives to attract enough farmers to make this work? How difficult will it be to implement and monitor these carbon capture methods? Will some farmers benefit more than others? Will farmers be credited for the steps they have already taken to reduce greenhouse gas emissions?
The carbon cycle
Carbon is constantly roaming the planet Earth. The light energy of the sun serves as fuel for the carbon cycle – a natural process that moves carbon in our atmosphere, our biosphere, our pedosphere, our lithosphere and our oceans.
“Human activity has created the need to extract huge amounts of deeply sequestered fossil carbon in the form of fossil fuels,” explained Katie Lewis, Ph.D. with Texas A&M AgriLife Research, researcher in soil fertility in the Department of Soil and Crop Sciences, Lubbock. “When burned, these dense forms of carbon release massive amounts of carbon dioxide.”
She said more carbon dioxide is now being released than plant life on Earth and the oceans can naturally reabsorb. This excess carbon dioxide forms a blanket in our atmosphere, trapping heat from the sun and causing climate change.
Around the world, it is estimated that soils contain about 10 times more carbon in the atmosphere – far more than what is found in normal vegetation.
“Carbon cultivation is seen as a way to help restore balance in the carbon cycle,” Lewis said. “It also helps the soil to strengthen its resistance to drought and increase agricultural productivity in a natural way.”
What is carbon agriculture?
“The idea behind growing carbon is quite simple: to remove excess carbon from the atmosphere and store it in the soil, where it will facilitate plant growth,” Lewis said.
Carbon farming involves the implementation of agricultural practices that improve the rate at which carbon dioxide is removed from the atmosphere and converted to plant matter and soil organic matter. It works by applying agricultural methods such as direct seeding or conservation tillage for minimal soil disturbance, mulching, composting, livestock rotation and the use of cover crops as a means of sequestering carbon in the soil. ground.
“The loss of carbon from the soil is primarily due to the removal of plant material that contains carbon, usually at harvest,” Lewis said. “Changes in land management can increase or decrease soil carbon, creating a new balance. The variation of the climate can also modify this balance. Carbon cultivation can be considered successful when the net amount of soil carbon captured or sequestered exceeds the amount lost. “
Lewis said that to accurately estimate carbon storage or stocks in soil, soil samples should be collected at a depth that will determine bulk density and organic carbon using a dry combustion method.
“Bulk density is necessary to convert the percentage of organic carbon to an actual amount of carbon in the soil, a stock,” she explained. “The depth of sample collection will depend on soil depth and crop history. Deeper depths are likely where the storage potential is greatest. “
Lewis said another method of estimating carbon storage is to use a modeling approach based on management practices implemented on a farm.
“The results of the model should then be verified using laboratory tests,” she said.
In all, the Natural Resources Conservation Service, NRCS, from US Department of Agriculture identified at least 32 on-farm conservation practices known to improve soil health and sequester carbon. These practices also offer other benefits in terms of water retention, hydrological function, biodiversity and resilience.
Bet on a carbon bank
“Recently there have been discussions about creating a ‘carbon bank’ at USDA that would buy and sell carbon credits to farmers,” Outlaw said. “The credits could then be sold to companies needing to offset their emissions.”
This concept, which has received support from a number of agricultural, food, forestry and environmental groups, also accommodates early adopters who pioneered carbon sequestration practices.
“There hasn’t been a national cap-and-trade effort here in the United States for over a decade, but currently there appears to be a growing demand for carbon offsets,” Outlaw said. “There are already a number of private credit markets or carbon payment programs being considered or developed. This seems to support the idea that carbon farming could potentially be a way for farmers to generate additional income.
He noted, however, that for the comprehensive carbon agriculture framework to be successful, it would need to include strong policies, public-private partnerships, precise quantification methodologies and supporting funding to implement. effectively direct, science-based solutions.
“It will also need to be done at a scale where we can achieve measurable carbon capture that promotes regenerative agriculture focused on creating and maintaining healthy soils that absorb and store carbon,” he said.
Is carbon farming sustainable?
The jury is still out on whether carbon farming can be sustainable in the long run.
“There are many technical and regulatory hurdles to overcome, as well as concerns from some environmentalists that even its widespread implementation will not significantly reduce greenhouse gas emissions or provide only a temporary solution,” he said. declared Outlaw.
He said it was also of concern that carbon farming mainly benefits certain agricultural regions. Additionally, many farmers may not be able to afford the cost of implementing environmentally beneficial measures without some kind of financial assistance.
Some farmers were able to receive government payments from the NRCS Conservation Stewardship Program to cover the cost of implementing certain conservation measures. However, this funding is capped by the Farm Bill and there is no long-term assurance of continued payments.
“Right now there is really no way to know if carbon farming would be an effective way to tackle climate change, but there is no doubt that there are many ways to bring changes in land management that would improve soil health and benefit the environment, ”says Outlaw.
Will carbon farming work for me?
Studies on organic carbon sequestration in soil show that the corn belt, with its good soil, mild climate and reliable rainfall, is one of the best prospects for sustainable carbon agriculture. In addition, areas of the southern United States with long growing seasons and sufficient rainfall, as well as those with substantial irrigation, provide viable opportunities for carbon cultivation.
“Carbon farming is likely to be more of a challenge for farmers in hot, dry regions of the country,” Outlaw said. “That’s why there appears to be support for a voluntary system that takes into account climatic differences while providing a range of options that farmers and ranchers can choose from in determining the best program for their lands.”
The USDA has a web tool called COMET-Farm to help farmers interested in transitioning to carbon sequestration practices. The tool provides a rough carbon footprint from user-supplied data and allows farmers to study different land management scenarios to see which one may work best for them. It also guides the user in describing farm and ranch management practices, including alternative future management scenarios. Once completed, a report is generated comparing the carbon changes and greenhouse gas emissions between current management practices and future scenarios.
“As an economist and person who has spent many years in agriculture, I would advise producers to do their homework and weigh the advantages, disadvantages and costs of carbon farming against its advantages. economic and other potentials for their activities, and then decide if it works for them.