INNOVATIVE OPERATION

GROWING WORMS WITH FOOD RESIDUALS

To prepare the proper medium for worm production, preconsumer organics are Collected from local restaurants, then blended with other materials in windrows and com posted.

Molly Farrell

Reprinted by permission from BioCycle July 1997 pages 65-66

Flying Heart Farm in Ojai, California got started in the worm business three years ago when owner Ivor Benci-Woodward purchased a small amount of California golden giant worms (also known as "plumps" and "Georgia jumpers"). To feed the worms, he hired a part-time employee to collect preconsumer food residuals twice a week from eight local restaurants. The worms consume about 800 pounds per week.

The worms are grown in a mixture of restaurant residuals and composted wood chips, manure and yard trimmings that have been run through a chipper. Area soils have the consistency of adobe and are so poor that the worms would be unable to burrow through it if no other amendments were used. Consequently, preparation is crucial. When starting a new row, Benci-Woodward digs beds four feet wide, 40 feet long and two feet deep, then adds a six foot layer of bulking agent (four feet of which is above the ground). A soaker hose is run through the row to control the temperature of the materials while they compost in the 100F summer heat. Materials are composted for a year, and during this time, rows are turned with a tractor that has a tine bar resembling a big fork on the front of it. When materials have degraded to ground level, the soaker hose is pulled out, the bed is tested for pH and salt levels, and worms are introduced. Eventually a row this size will contain approximately 250,000 worms.

ADDING SCREENED MATERIALS Every four days, two inches of food residuals are laid out over the worms and covered with three inches of compost which is first screened with a trommel. According to Benci-Woodward, if the recycled food wasn't covered, the worms wouldn't eat it because it would get too hot. The worms eat up through the pile and consume the food within two days. "We wait another two days before adding more to make sure that they're hungry," he says.

Worms must be protected from Ojai's temperature extremes, which fall below 32 F in the winter and rise above 110 F in the summer. A sprinkler system is activated by a solar computer when moisture levels get too low during the summer. A sensor in the piles determines when moisture levels fall below 22 percent and turns on the sprinklers until moisture levels reach 44 percent.

It takes eight months for a row to get to the proper height for harvesting, says Benci-Woodward. The operation uses an electric, self-propelled harvester that straddles a row to collect and separate worms, worm eggs, and castings. Both worms and castings are thrown into the front of a long tube with a rotating screen that is small enough to only permit the soil to fall through. The back of the harvester is shaped like a lamp-shade eight to nine feet in diameter. Any remaining worms, because they are sticky, stay on the "lampshade." The castings, because they are heavier and not sticky, fall to the ground.

Some eggs are kept to reseed the rows, and the rest are sold. Additional castings are screened out from the remainder of a windrow with a trommel screen. The farm currently has 12 rows in production which are reported to yield a total harvest of around three million worms each year from May to November. The farm keeps an additional 100,000 worms in shipping trays, ready for delivery. They are fed the same food residuals as the worms in the rows and are kept moist during the one to two months they may be in the trays.

MARKETING AND EDUCATION

In addition to selling worms wholesale, the farm has other ventures including retail sales of worm castings and worms, giving educational and technical tours, and establishing vermiculture programs at elementary schools. Marketing is a family affair. "My wife Deborah and our children help harvest the worms, separate out the castings, package them and bring them to the nurseries," Benci-Woodward says.

The farm produced 25 tons of worm castings in 1996. Benci-Woodward began selling the castings at retail outlets in February in one-pound boxes made of recyclable cardboard printed in soy ink. To prevent moisture in the castings from seeping into the cardboard, the castings are first put in #4 plastic bags. He tried using a paper bag at first, but says the castings absorbed moisture from the atmosphere at nurseries located near the ocean, which caused the boxes to fall apart.

On weekends, customers can drive to the farm and purchase worms on a self-service basis for $12 a pound. The customers are given a coffee can and a pair of rubber gloves, scoop the worms into the can with a garden spade, and weigh the cans on a scale.

JULY 1997 BIOCYCLE pages 65-66