Biologically Integrated Agriculture

Sierra Cascade Farm uses the wildlife on the farm to their advantage instead of seeing it as an adversary.

By John Carlon

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When I started Sierra Cascade Farm, an organic blueberry farm in Northern California, I considered gophers to be an adversary. I came to realize that their burrows benefited the farm by providing a nesting habitat for the native bumblebees that pollinate blueberries. The idea that an ecosystem full of diverse creatures could contribute to my agricultural pursuits, and specifically my experience with gophers and bumblebees, changed my perspective on farming. I realized that being certified organic is really just the first step in the transition to a more biologically integrated approach to agriculture.

A main principle of organic agriculture is to stop poisoning the land you farm. Once this is accomplished, you have the opportunity to employ natural biological processes to support crop plants. As my confidence in nature grew, I looked for other opportunities to change my farming practices. Here are some examples of changes I’ve made.

Robins and Cooper’s hawks. Robins and other birds damaged my crop more than any other pests. I tried several mechanical methods of control—all expensive and problematic. Now a pair of Cooper’s hawks protects my crop from feeding birds, saving me tens of thousands of dollars per year.

Spiders and grasshoppers. After 15 years with no applications of any kind of pest control, the insect-predator-to-pest ratio on the farm has reached a stable equilibrium. Although the fields are full of a wide diversity of insects, I experience virtually no crop damage or loss from insects.

Native and exotic plants. Our basic philosophy is to optimize the presence and diversity of native plants by working to reduce the number, and percent cover, of exotic plants. Short-term weed control is done by hand-pulling or mowing. The long-term strategy is to displace the exotic weeds with natives. The percentage of native plant cover slowly increases each year.

Soil flora and fauna. Soils on the farm are rich in fungi, bacteria, mycorrhizae, earthworms, and other soil organisms—due in part to mechanical weed control and a mulch of pruned materials that have been ground through a chipper. A resident cover crop and a 1-to-3-inch, spongelike layer of thatch soak up rain without any surface runoff. The soil is biologically active, capable of rapidly digesting organic matter, retaining and slowly releasing nutrients and moisture.

Nematodes and diseases. We do not apply any materials to protect against, and have not experienced any loss or damage from, diseases or nematodes.

Fences and fertilizers. After breaching my fences and welcoming wildlife onto my farm, I have applied no fertilizer, compost, or manure for the past 4 years. My wife and I have either sighted or observed signs of mountain lions, black bears, bobcats, deer, coyotes, raccoons, skunks, rabbits, wood rats, gophers, voles, and mice on our farm. A large number of both resident and migratory birds visit the farm. All of these animals combined contribute a constant supply of urine and manure that activates our soil and fertilizes our farm.

Flathead borers and water deficiency. Flathead borers began attacking my blueberry bushes, and rather than kill the insects I increased my irrigation rate, which stopped the borer damage. It turns out flathead borers are good indicators of water stress in blueberry plants.

Rabbits and iron deficiency. The growth of the rabbit population mirrored the rise of the gophers. Unlike gophers, the rabbits ate young, new shoots at the base of specific blueberry varieties. The varieties under rabbit attack all suffered from iron deficiency. Like the flathead borers, the rabbits attacked only the weakest plants. Enlarging the wetted area of our drip irrigation system improved nutrient uptake, and the rabbit damage decreased.

Biodiversity and sanitation. Our approach to ensuring good sanitation in the production of our blueberries is to optimize biodiversity. Rich soils, clean water, healthy wildlife, and abundant sunlight have kept our farm free of pathogen outbreaks.

Twenty years ago, my family and I farmed most of our property. Today, out of the 61 total acres we own, we actively cultivate 8 1/2 acres. Our homestead and roads occupy another 5 1/2 acres. We are returning the balance of the property, 47 acres, back into native forest. We are doing this not only because we enjoy the forest but because we believe it is a sound business decision. The 47 acres of wildland provides rainwater harvest, carbon sequestration, and refuge for our wildlife. It’s a pool of biodiversity surrounding and supporting our farming operation.

Contrary to what I was taught in college, this approach to agriculture is actually a stable business model. Every time we have replaced off-farm inputs with ecosystem services, our profits have increased. Every time we have increased biodiversity on the farm, our profits have increased. Our yields are consistent with state averages and our fruit is recognized for its quality. Although small in size, our farm constitutes a viable economic unit; our gross sales place us in the upper 12 percent of all farms nationwide.

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