“As much as one third of the surplus CO2 in the atmosphere driving climate change today has come from land management practices that cause loss of carbon, as CO2, from our working lands.”
- Marin Carbon Project
It is well known that the amount of carbon currently in the Earth’s atmosphere has reached dangerously high levels. Humanity needs to not only reduce carbon emissions, but also to capture and store carbon. Terrestrial environments are an important carbon “sink” that are often overlooked in conversations about global climate change. The fact remains that industrial agricultural practices, such as heavy tillage of soil, intensive livestock production, burning of fossil fuels during machine operation, and the use and production of agricultural chemicals, accounts for 20-30 percent of all human made greenhouse gases in the atmosphere (Roulac, 2015). By focusing on improved land management practices, carbon can be sequestered in large quantities through a method known as Carbon Farming.
Approaches to land and farm management can be adopted that reduce, eliminate, or otherwise change degrading practices, resulting not only in a reduction of CO2 (carbon dioxide) emissions, but an increase in CO2 sequestration. As affirmed by soil scientist Dr. Rattan Lal, “A mere two percent increase in the carbon content of the planet’s soils could offset 100 percent of all greenhouse gas emissions going into the atmosphere.” Implementing a Carbon Farming management plan that focuses on building healthy soils will result in economically, ecologically, and environmentally productive land that will be able to sequester tons of carbon in a stable state.
What is Carbon Farming?
Graphic credit: Intergovernmental Panel on Climate Change (IPCC)
Carbon farming is an active response to global climate change. It works to mitigate climate change by increasing the rate at which carbon is stored in soil organic matter to the point that it surpasses the rate at which it is being emitted into the atmosphere. This reduction in atmospheric CO2 has the potential to slow and possibly reverse the current trends of global warming.
As a land management practice, carbon farming aims to store carbon in vegetation and soil. According to the EPA, carbon dioxide (CO2) and methane (CH4) are the most prevalent greenhouse gases produced in the United States. In 2012, total greenhouse gas emissions amounted to 6,526 million metric tons of carbon dioxide equivalent.
U.S. Greenhouse Gas Emissions in 2012. Image credit: EPA
Through management and conservation, landowners can increase the rate at which CO2 is removed from the atmosphere and converted to organic matter or vegetation. By managing land for soil carbon sequestration, carbon can be stored in soils for centuries.
Approaches to Carbon Farming
In addition to sequestering carbon, the following methods of land management can be used to restore degraded land, to transform lawns (which are water and fossil fuel intensive) to native grasslands, and to move from overly grazed land to a restorative planned grazing system.
Many carbon farming plans include the application of compost to the soil. When compost or organic matter in added, carbon is being added directly to the soil, some of which can be stored in a stable state (Ryals et al., 2014). Additionally, there is the opportunity for increased plant production due to increased levels of nitrogen and increased water retention capabilities. Utilizing compost or other organic matter can also help to avoid methane (CH4) emissions from the diversion of organic wastes from landfills or slurry ponds (DeLonge et al., 2013) .
Favoring perennial over annual vegetation will generally increase the carbon sequestration capability of a system. Coppice and biomass systems can sequester 1-6 tons/hectare/year, tree crops and bamboo 2-28 and 6-33 tons/hectare/year, and multistrata agroforestry systems sequester 4-40 tons/hectare/year (Toensmeier, 2014). A well managed annual system will only sequester 1-2 tons/hectare/year, making perennials the clear winners in the carbon farming game.
When animals are integrated into a Carbon Farming system, management strategies such as the Holistic Planned Grazing system are “effective, profitable, and culturally relevant” (The Savory Institute, 2013). This is exemplified through the experience of John Wick, a rancher from Nicasio, California. “Every year I produce 50,000 pounds of grass-fed beef on land that was once considered heavily degraded. We restored the productivity of our land by replenishing the soil carbon content....Rigorous, peer-reviewed science shows that it is indeed possible to increase soil carbon sequestration on grazed lands, and that doing so initiates a cascade of beneficial effects that improves their ecological condition.” 7 (Congressional Hearing on Increasing Public Lands Carbon Soil Sequestration, 2014). For an in-depth look at the storage of carbon through Holistic Planned Grazing, see the paper “Restoring the climate through capture and storage of soil carbon using Holistic Planned Grazing” from The Savory Institute (The Savory Institute, 2013).
Getting Started with Carbon Farming
Adding compost to vacant and degraded urban lots creates an excellent canvas for new plant colonization and carbon fixation. This image shows installation along the Brooklyn waterfront that One Nature designed for the Brooklyn Greenway Initiative. Hundreds of tons of municipal compost were used to create a native plant meadow with the help of volunteer labor.
Photo credit: One Nature
Although a Carbon Farming plan will be different for a ¼ acre of urban land than for a 10,000 acre production farm, both plans will address the same issues of building soils for carbon storage and reducing carbon emissions. The differences will be in the equipment and maintenance, which will vary greatly depending on the scope of the land. Each plan should take into account equipment needs, initial inputs, maintenance options, and revenue goals, as well as opportunities for crop production, livestock production, or carbon credits.
For example, a 50 acre corporate or campus property that is primarily a mowed turfgrass lawn can be converted to a Carbon Farmed property with a comprehensive land management plan. Initial inputs will include compost, grass seed, and labor to convert the turf grass (a water and fossil fuel intensive system) to a native and resilient perennial grass system. By converting the lawn to improved grass species, the system will be better adapted to local climate, more resilient, more resistant to drought, and able to enhance soil fertility (Food and Agriculture Organization of the United Nations, 2010). This will lead to greater carbon inputs and carbon storage. Maintenance options include mowing and/or haying the property one to three times per year, depending on the region and species of grasses planted. Possible revenue sources include hay production and carbon offset sales or credits.
Estimates of the amount of total carbon sequestered can be generated to determine if the landowner would qualify to sell carbon offsets or receive emission reduction credit. The dynamics of grass biodiversity and carbon storage are complex; the total amount of carbon sequestered will depend on the varieties of grasses planted, the intensity of the management, and regional factors. In California, farmers receive tradable greenhouse gas emission reduction credits, which they can sell on California’s Greenhouse Gas Reduction Exchange. National carbon credit systems have just started to begin for ranch grassland, and are under development for beef, dairy, and crop farms (SustainableBusiness.com, 2014).
For a different example, grazing can be integrated into a grassland system. The initial conversion of the land to more resilient perennial grasses will be similar to the previous example, however more infrastructure and labor will be needed to implement a holistic grazing system. This will increase the operating labor and costs, however the revenue from the system can also increase. Additionally, the amount of carbon sequestered may potentially increase since these grazers will be actively aerating, fertilizing, and restoring the soil (Savory Institute, 2013).
Taking action: Becoming a Carbon Farmer
Once a landowner has evaluated the potential of their land for carbon farming, the process of implementing these new land management practices can begin. Hiring experts during this process who have knowledge of ecological landscape restoration, sustainable landscape design, and sustainable agriculture will ensure that the land is managed to its maximum potential. Grass species selection, equipment rental, and compost sourcing are all things that can be effectively managed by professionals in this field. There is opportunity to create a native grassland habitat that is aesthetically remarkable and self-sustaining, and a team of experts will be able to provide a design and plan for a Carbon Farm that exemplifies these qualities. Future maintenance and monitoring can also be provided in order to manage for maximum carbon storage.
Sources:
1. Congressional Hearing on Increasing Public Lands Carbon Soil Sequestration. 2014. http://globalcompostproject.org/increasing-carbon-soil-sequestration-on-public-lands/
2. DeLonge MS, Ryals R, and Silver WL. 2013. “A Lifecycle Model to Evaluate Carbon Sequestration Potential and Greenhouse Gas Dynamics of Managed Grasslands.” Ecosystems. http://link.springer.com/content/esm/art:10.1007/s10021-013-9660-5/file/MediaObjects/10021_2013_9660_MOESM1_ESM.pdf
3. EPA, 2012. http://www.epa.gov/climatechange/images/ghgemissions/gases-overview.png
4. Food and Agriculture Organization of the United Nations. 2010. “Challenges and opportunities for carbon sequestration in grassland systems. A technical report on grassland management and climate change mitigation.” Integrated Crop Management. http://www.fao.org/fileadmin/templates/agphome/documents/climate/AGPC_grassland_webversion_19.pdf
5. Marin Carbon Project, 2013. http://www.marincarbonproject.org/
6. Roulac, JW. 2015. “The Solution Under Our Feet: How Regenerative Organic Agriculture Can Save the Planet ” EcoWatch. http://ecowatch.com/2015/01/06/regenerative-organic-agriculture/
7. Ryals R, Kaiser M, Torn MS, Berhe AA, and Silver WL. 2014. “Impacts of organic matter amendments on carbon and nitrogen dynamics in grassland soils.” Soil Biology & Biochemistry. http://www.fibershed.com/wp-content/uploads/2013/11/Ryals_et_al_2014.pdf
8. The Savory Institute. 2013. “Restoring the climate through capture and storage of soil carbon using Holistic Planned Grazing.” http://www.savoryinstitute.com/media/40591/Savory_Institute_Carbon_RestoringClimateWhitePaper_April2013.pdf
9. SustainableBusiness.com. 2014. “Carbon Farming Gaining Traction In US.” http://www.sustainablebusiness.com/index.cfm/go/news.display/id/26014
10. Toensmeier, E. 2014. “Carbon Farming Practices.” 2014. http://carbonfarmingcourse.com/blog/carbon-farming-practices-by-eric-toensmeier