Tuesday, January 1, 2013

Worms Produce Another Kind of Gold for Growers

Under rows of old chicken sheds, Jack Chambers has built an empire of huge metal boxes filled with cattle manure and millions of wriggling red worms.

“My buddies all had planes and boats,” said Mr. Chambers, 60, a former airline pilot. “I have a worm farm.”

Mr. Chambers’s two decades of investment in what he calls an “underground movement” may be paying off. New research suggests that the product whose manufacture he helped pioneer, a worm-created soil additive called vermicompost, offers an array of benefits for plants — helping them grow with more vigor, and making them more resistant to disease and insects, than those grown with other types of composts and fertilizers.

The earthworm’s digestive process, it turns out, “is a really nice incubator for microorganisms,” said Norman Q. Arancon, an assistant professor of horticulture at the University of Hawaii at Hilo.

And these microbes, which multiply rapidly when they are excreted, alter the ecosystem of the soil. Some make nitrogen more available to plant roots, accounting for the increased growth. The high diversity and numbers of microbes outperform those in the soil that cause disease.

By contrast, Dr. Arancon said, soil that has been heavily exposed to synthetic fertilizers, pesticides and herbicides lacks microbial richness and diversity, qualities that can be restored naturally by adding the microbes from worms.

Some experts and entrepreneurs hope earthworms can also help with another problem: the growing piles of animal waste from dairy farms and other agricultural operations.

Worm Power, a company in Avon, N.Y., transforms 10 million pounds of manure from a single dairy herd each year — about 40 percent of the cattle’s output — into 2.5 million pounds of vermicompost. Tom Herlihy, a former municipal waste engineer who founded the company in 2003, says it has raised more than $6 million in venture capital and $2 million in grants for research, much of it at Cornell University.

Here in Northern California, Mr. Chambers’s Sonoma Valley Worm Farm produces about half a million pounds of similar compost, an amount he plans to increase in the spring. He loads a long metal bin with cow manure and 300,000 to 400,000 Eisenia fetida, or red wigglers — weighing 300 to 400 pounds. In their wake, the worms leave cattle waste that has been processed into rich and crumbly castings that look like fine peat moss.

It takes six months for a vermicompost bed to become fully mature, by which time a million worms roam the manure. Mr. Chambers continues to add two yards of manure and harvest one yard of worm compost weekly. The finished product is shaved, an inch at a time, off the bottom of the bin. An established bed can go on this way for years.

by Jim Robbins, NY Times |  Read more:
Photo: Ramin Rahimian