San Diego Foundation Climate Initiative Grant: Catalyzing Carbon Farming in San Diego County

Diagram: Marin Carbon Project

Diagram: Marin Carbon Project

We are thrilled to announce the launch of a new collaborative project to catalyze Carbon Farming in San Diego through a generous $25k grant by the The San Diego Foundation's Climate Initiative! This is a collaborative project between the San Diego Food System Alliance, Batra Ecological Strategies, Resource Conservation District of Greater San Diego County, and County of San Diego. The funding by The San Diego Foundation enabled the Resource Conservation District of Greater San Diego County to receive $10k from Jena and Michael King Foundation to develop San Diego County's first carbon farm plan at Montado Farms.

Carbon Farming is a process designed to maximize agriculture’s potential for moving excess greenhouse gases from the atmosphere into soil and vegetation, building fertility, productivity and resilience. Carbon Farming is a whole-farm approach implementing on-farm practices that increase the rate at which plants transfer carbon dioxide (CO2) from the atmosphere to the soil, which then increases water infiltration, water-holding capacity, soil organic matter and promotes long-term carbon sequestration. More on Carbon Farming:

Carbon Farming practices defined by USDA's Natural Resources Conservation Service include (not all may be relevant for San Diego):
Compost Applications, Anaerobic Digester, Riparian Forest Buffer Establishment, Prescribed Grazing, Cover Crops, Silvopasture/ Shrub & Tree Establishment on Grazed Grasslands, Conventional Tillage to No-Till, Range Planting, Forage and Biomass Planting, Windbreak/ Shelterbelt/ Hedgerow Establishment and Renovation, Filter Strip, Riparian Herbaceous Cover, Critical Area Planting, Grassed Waterway, Field Border,  Conservation Crop Rotation, Improved Nutrient Management, Multistory Cropping/ Strip Cropping/ Alley Cropping

Out of all the practices listed, compost application has been shown to have a significant impact for sequestering carbon. A study conducted by UC Berkeley's Dr. Silver and Dr. Ryals of the Marin Carbon Project demonstrated that building healthier soil through a one-time application of a 1/2 inch layer of compost on grazed rangeland increased long-term carbon storage by 1 ton of carbon per hectare and increased forage production by 40-70%. The practice also led to increased water holding capacity to 26k liters per hectare. Soil's water retention capacity is important in this time of drought and San Diego's dry climate. 

Late last year, Montado Farms in Santa Ysabel, operated by Kevin Muno, was selected as the southernmost of the 17 sites across the state where compost application research is being expanded by scientists of Marin Carbon Project. After taking soil samples, researchers spread one-quarter inch of compost over one half of a one-acre site marked off on a hillside to show the levels of carbon sequestration. Over the next several years, the soil will be regularly tested to compare results against the original two study sites by Marin Carbon Project, which have still shown positive results for all of the noted benefits eight years after the single compost application. More on Montado Farms pilot test here

San Diego County is uniquely positioned to encourage these Carbon Farming practices, with the largest number of small and organic farms in the country. There are over 5,000 small farms in the county and 208,564 acres of rangeland. Permanent crops, such as San Diego County’s top food crops, citrus and avocados, are already effectively storing carbon. Farmers in San Diego County currently have in excess of 3 million trees, which sequester approximately 48 pounds of carbon per tree per year. 

Based on estimates by Marin Carbon Project consultants, costs and feasibility aside, the diversion of organics from landfill and application of compost on 200k acres of rangeland could mitigate and sequester a total of 3,065,988 MTCO2e of additional carbon over 10 years. Carbon Farming is a promising and practical solution to address climate change. 

This exploration project for San Diego County involves two parts:

Part I: Assessment of the opportunities to sequester carbon, fund carbon farming, and synergize with other programs in San Diego County
a) How much net GHG reduction can be achieved through carbon farming in San Diego County?
b) What funding mechanisms exist for conversions to carbon farming? What financial incentives might be employed to maintain carbon farming as an economically viable activity?
c) What state and local policy synergies exist that are compatible with the goals of carbon farming?

Part II: Piloting the carbon farm planning process at one farm in San Diego County

The goal is to complete both parts by end of June to inform the County of San Diego's Climate Action Plan process and to prepare for CDFA's Healthy Soils funding available in July.

The State is ahead of local jurisdictions in recognizing the potential of Carbon Farming. In an effort to further the vision of California's Global Warming Solutions Act (AB 32), Governor Brown identified key climate change strategy pillars to reduce emissions and meet the 2030 greenhouse gas emissions target. One of the six pillars includes "managing farm and rangelands, forests and wetlands so they can store carbon." To support with the implementation of this goal, the State recently funded the Healthy Soils Initiative, a collaboration of State agencies and departments led by California Department of Food and Agriculture (CDFA), to provide resources for farmers and ranchers to increase carbon stores in agricultural soils. 

Can farmers become part of the climate change solution? Stay tuned and find out more! We plan to share the findings of the analysis sometime this fall.