What is Carbon Farming?
Carbon constantly cycles in and out of plants, soil, and air. Your garden, landscape, or farm is active in the following processes:
- Plants pull carbon dioxide (CO2) from the atmosphere during photosynthesis
- Plants deposit some of that carbon into the soil (in forms of leaf litter, decaying roots, and the sugars leaked from living roots)
- Microbes consume some of that carbon while continually reproducing and dying. Microbes "respirate" some of that carbon back into the atmosphere as carbon dioxide (CO2), while the rest of the carbon slowly incorporates into the soil.
Carbon farming takes a wholistic view of your garden, landscape, or farm, and asks two questions: 1) "How can I help my plants and soil maximize the amount of carbon dioxide (CO2) removed from the atmosphere?" and 2) "How can I maximize the amount of carbon that is stored (or sequestered) in my soil? By answering these questions, we can help improve our soil's health all while reducing greenhouse gases and mitigating climate change.
Carbon farming practices provide answers the two above questions! Each practice focuses on growing healthy plants, supporting root systems, and building up the soil ecosystem with beneficial fungi, bacteria, and invertebrates. Overtime, we can see indirect clues that our soil carbon is increasing. Landscape manager and farmers can even test their soil to directly measure soil carbon changes overtime (see examples below).
Carbon Farming Practices for Gardeners and Landscapers
- Feed your soil with compost to encourage microbial activity and plant growth. Compost also improves the water-holding capacity of soil, making it more resilient to drought and flooding.
- Maximize continuous living roots by establishing woody perennial plants. If you grow annual vegetables, plant cover crops after you harvest and alongside your crops. Plant roots exude carbohydrates that feed soil microbes.
- Keep unplanted areas covered with a thick layer of mulch such as wood chips, straw, tree leaves, or compost. Mulch helps soil retain moisture, encourages microbial activity, and prevents erosion. Groundcover plants and low cover crops also act as "living mulches" and are an excellent mulching solution.
- Minimize disturbance. Erosion, compaction, and rototilling can harm soil microbes and release carbon to the atmosphere. Instead of tilling, try sheet mulching when preparing your garden beds.
- Avoid synthetic fertilizers, pesticides, and herbicides which harm the microorganisms that play an important part in storing carbon in the soil. Also, applications of synthetic nitrogen fertilizer can cause nitrous oxide emissions, a greenhouse gas that traps 300 times more heat than carbon dioxide.
- Maximize biodiversity. The more diverse the above ground plant community is the more diverse the below ground soil food web will be. A thriving soil food web is excellent habitat for beneficial microbes, and also helps prevent pests and pathogens from harming your plants.
The Carbon Cycle Institute provides a more holistic set of Carbon Farming practices for farmers, ranchers, and working lands, and the Alameda County Resource Conservation District provides technical assistance relating to Carbon Farming.
