Why Carbon Farming?
Land management is the second largest contributor to carbon dioxide emissions on planet earth. Agriculture is the ONE sector that has the ability to transform from a net emitter of CO2 to a net sequesterer of CO2 — there is no other human managed realm with this potential. Common agricultural practices, including driving a tractor, tilling the soil, over-grazing, using fossil fuel based fertilizers, pesticides and herbicides result in significant carbon dioxide release. Alternatively, carbon can be stored long term (decades to centuries or more) beneficially in soils in a process called soil carbon sequestration. Carbon Farming involves implementing practices that are known to improve the rate at which CO2 is removed from the atmosphere and converted to plant material and/or soil organic matter.
Carbon farming is successful when carbon gains resulting from enhanced land management and/or conservation practices exceed carbon losses.
Research by the Marin Carbon Project scientists indicates that a single application of a half-inch layer of compost on grazed rangelands significantly increases forage production (by 40-70%), increases soil water holding capacity (to 26,000 liters per hectare), and increases soil carbon sequestration by at least 1 ton per hectare per year for 30 years without re-application. Compost decomposition provides a slow release fertilizer to the soils, which, with improved soil moisture conditions, leads to increased plant growth. More plant growth leads to more carbon dioxide being removed from the atmosphere through the process of photosynthesis, leading to increased transfer of carbon dioxide through the plant to the soil as roots, root exudates and detritus, yielding additional soil carbon and water holding capacity increases. More water and more soil yields more plants, and the cycle ascends and spirals regeneratively, all from one initial compost application.
Implications for Our Climate
According to Marin Carbon Project research, sequestration of just one metric ton per hectare on half the rangeland area in California would offset 42 million metric tons of CO2e, an amount equivalent to the annual green house gas emissions from energy use for all commercial and residential sectors in California.
Grasslands Are Key
Initial research was conducted on actively grazed rangelands. There are 23 million hectares of rangeland in California alone, and it is the largest land type on our planet today. Grasslands co-evolved with ungulates (hoofed animals) over millions of years. Properly scaled in space and time, grazing stimulates plant growth through a variety of mechanisms, resulting in increased carbon capture by the grazed ecosystem. Grasslands have great potential to function as a sponge for carbon dioxide from our atmosphere. However, test plots where grazing alone was measured continued to lose more carbon than they sequestered, illuminating that our rangelands might require a practice in addition to grazing to restore their natural carbon cycle balance. Test plots where compost was applied showed the greatest carbon sequestration gains. Not only has compost applied to grazed lands been demonstrated to be an effective way to increase soil carbon sequestration, it is also a proven method for avoiding emissions related to the anaerobic decomposition of organic waste material in landfills.
Efforts are now underway to adopt the compost protocol at state, national and international levels to support the financial incentivizing of this practice for the benefit of the landowner and the climate. The non-profit organization known as the American Carbon Registry (ACR) has approved a voluntary methodology for greenhouse gas emission reductions from compost additions to grazed grasslands. The ACR is a leader in creating high standards and protocols and has issued 37 million carbon off-sets since its inception.
In Addition to Compost…
Preliminary Carbon Farm Practice List
(The majority of these practices were selected from the USDA-NRCS GHG Ranking Tool)
- Mulching/compost application
- Residue and Tillage Management, No Till/Strip Till/Direct Seed
- Anaerobic Digester
- Multi-Story Cropping
- Windbreak/Shelterbelt Establishment
- Silvopasture Establishment
- Forage and Biomass Planting
- Nutrient Management
- Tree/Shrub Establishment
- Forest Stand Improvement
- Contour Buffer Strips
- Riparian Restoration
- Riparian Forest Buffer
- Vegetative Barrier
- Windbreak/Shelterbelt Renovation
- Alley Cropping
- Riparian Herbaceous Cover
- Range Planting
- Herbaceous Wind Barriers
- Critical Area Planting
- Residue and Tillage Management
- Forest Slash Treatment
- Filter Strip
- Grassed Waterway
- Hedgerow Planting
- Cross Wind Trap Strips Conservation Cover
- Wetland Restoration
The Carbon Cycle
Carbon constantly cycles through five pools on planet earth. Light energy coming from our sun functions as the fuel for the carbon cycle. The carbon cycle is a critical natural process that moves carbon through our atmosphere, biosphere, pedosphere, lithosphere, and oceans.
Human activity has tipped the balance of the carbon cycle through extracting enormous quantities of deeply sequestered fossil carbon as fossil fuels. These dense forms of carbon, when burned, release massive amounts of energy and carbon dioxide.
More carbon dioxide is now being released than the earth’s land-based plant life and oceans can naturally reabsorb. The excess carbon dioxide has formed a blanket in our atmosphere—trapping the sun’s heat and changing our climate, as seen in shifts in our earth’s jet stream, ocean currents, and air temperature. Rainfall patterns are changing and glaciers (water storage for many communities) are melting quickly.
We have an opportunity to restore balance within the carbon cycle in a way that will ameliorate climate change, build resilience to drought and increase our agricultural productivity naturally. This natural solution is called Carbon Farming.