2016-03-04

The San Diego City Council voted unanimously this week to implement AB 551, a state law passed in 2013 that lets urban areas create “urban agriculture incentive zones” within which private landowners can secure a property tax reduction by committing their land to urban agriculture for at least five years.

This is a very welcome development. The benefits of urban agriculture are well established and include access to community gardens, revitalization of vacant lots, increased availability of fresh fruit and vegetables and healthy outdoor physical activity.

When most people think “agriculture” they probably picture rows of crops, barns, farm animals and raised beds in a school or community garden.

Agriculture by one definition is “the cultivation of animals, plants, fungi and other life forms for food, fiber, biofuel, medicinal and other products used to sustain and enhance human life.”

San Diego will benefit from an expansive interpretation of the word – one that includes growing healthy soil as an end in itself.

Setting up an urban farm or community garden is not easy. It takes resources, labor, money, time and commitment. And the return on investments can take a long time to materialize.

But growing healthy, living soil, which is characterized by dynamic ecosystems of microbes, fungi, beneficial insects, earthworms etc., is surprisingly easy. It takes an application of organic matter, usually compost, some seeds, a few other simple things and then getting out of the way to let nature go to work. The results are almost immediate and last indefinitely.

The benefits of doing this include retaining stormwater and sequestering atmospheric carbon, functions that are tailor-made for our climate and location. Healthy soil has the ability to retain water, and the potential to sequester carbon.

Every pound of additional carbon sequestered in the soil represents 3.67 pounds of carbon dioxide removed from the atmosphere. And soils with high clay content, like we have here, are often much more responsive to soil carbon sequestration interventions.

Growing healthy soil is an affordable, practical, shovel-ready way to meet many of the goals for greenhouse-gas reductions that several cities in San Diego County have recently committed to in the form of climate action plans and zero-waste plans. The benefits of healthy soil will also help meet recently adopted regulations by the State Water Resources Control Board about limiting stormwater runoff, and could help re-charge dwindling groundwater supplies and aquifers.

This is not an either/or choice; healthy soil is really a prerequisite for successful farming and gardening, so this is a natural way to harness soil benefits while community groups or farmers organize resources for full-scale community farms or gardens.

Local leaders should take advantage of state law to incentivize private landowners to grow healthy soil.

Municipalities should also adopt these simple healthy soil practices on the hundreds if not thousands of acres that cities own.

Let’s think outside the conventional picture of agriculture, get some biology into our geology and make San Diego a leader in growing healthy soil.

Richard Winkler is co-director of Victory Gardens San Diego, a program of San Diego Roots Sustainable Food Project. Winkler’s commentary has been edited for style and clarity. See anything in there we should fact check? Tell us what to check out here.

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