Soil as a Carbon Sink

There are many environmental and health advantages of farming organically the way we do – fewer toxic chemicals released into the environment or consumed, safer conditions for farm workers not exposed to pesticides, safer food sources for pollinators, more attention to maintaining the diversity of both food crops and native flora and fauna, and a long list of other benefits. One area that is sometimes overlooked is the connection between farming and climate change.

We are happy to be connected with the California Climate and Agriculture Network. (We hosted a farm visit with CalCAN for state legislators including Mark Stone and Bill Monning in 2014.) CalCAN is involved in efforts to promote agricultural practices that will help to reduce climate change. Below is a brief discussion of the issues they have identified.  —  Jeanne

Soil as a Carbon Sink, by CalCAN

With climate change, scientists predict that California will experience more weather extremes that will put a huge strain on our community and on agriculture. Farmers and ranchers are among the first to experience the effects of climate change, including erratic weather, pest pressure, drought, yield decreases, and worker safety risks due to heat waves.

California’s farms and ranches produce two potent greenhouse gases—methane (mainly from livestock) and nitrous oxide (from fertilizers)—as well as the ubiquitous carbon dioxide from fossil fuel-powered equipment and pumps. Farmers can reduce emissions in a number of ways: replace petroleum-based nitrogen fertilizers with organic materials such as compost or manure; improve water use efficiency so less energy is required to pump it; produce on-farm renewable energy; and more.

There’s more good news: on-farm management practices can draw down carbon dioxide from the air, where it causes climate change, and store it in soil, vines and trees, where carbon is needed as a building block of life.

Techniques to build soil include the use of compost, cover crops, reduced tillage, and crop rotations. Grazing management strategies also can improve soil health and forage quantity. Conservation planting of hedgerows and other buffers adjacent to rivers and streams stores carbon in the woody plants. Many of these practices also provide additional environmental and health benefits both on and off the farm, such as improved air quality, habitat for pollinators and wildlife, improved water quality, and flood control.

Governor Jerry Brown understands the potential of farms and ranches to store carbon and reduce greenhouse gas emissions, and has launched a new Healthy Soils Initiative. He proposes spending $20 million in the coming year, using funds from the state’s cap-and-trade program, for grants to farmers and ranchers shifting to practices like those above. Hopefully the legislature will agree with him as they finish next year’s budget negotiations in June.

To learn more about the climate benefits of organic and sustainable agriculture, check out this summary or read about the Healthy Soils Initiative.
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This article was provided by the California Climate and Agriculture Network (CalCAN), a coalition of sustainable and organic agriculture organizations focused on climate policy. See www.calclimateag.org to sign up for a monthly newsletter.