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PRI's Environmental News Magazine

It's Super-Compost...Fortified with Essential Microorganisms

Air Date: Week of May 27, 1994

Gordon Black reports from Washington State on one county's attempt to make yard waste compost a marketable product. The owners of Land Recovery, Incorporated knew that compost from the yard waste of Pierce County wasn't likely to fetch a top price on the market — so they've enriched the compost with pest-fighting microbes to make a combined fertilizer and pesticide that's chemical-free.

Transcript

CURWOOD: Leaves, lawn clippings, and tree trimmings can easily be composed into organic fertilizer, but it's tough to find customers for commercial amounts of yard compost. But officials in Washington State's Pierce County aren't letting that stop them. In an effort to attract more customers at a higher price, they're mixing pest-fighting microbes into the county's compost, creating a chemical-free combined fertilizer and pesticide for farms, golf courses, and orchards. Gordon Black reports from Seattle.

BLACK: A smell reminiscent of a freshly-plowed field hangs in the air as you approach Pierce County's compost center in Purdy, 45 miles southwest of Seattle. Officials here are proud that making compost doesn't cause a stink with their neighbors. They've also designed a building that produces compost in a mere 16 weeks. Under a roof that could easily cover a football field lie piles of brown material: yard waste from throughout Pierce County that's in various stages of decomposition. This isn't just a bigger version of a backyard compost bin, though. It's custom-built to make compost on a grand scale.

(Fan vents blowing)

BLACK: Vents in the floor blow air into the piles which are watered and turned every week. Jeff Gage is recycling coordinator for Land Recovery, Inc.: the center's operator.

GAGE: The yard waste leaves brush, grass clippings, all of the material that comes in is being digested by microorganisms. We're trying to create an environment for those microorganisms so we can maximize the number of them , maximize the decomposition rate, how fast they eat the stuff up, and also keep it without problems such as odors, by providing exactly what those organisms want.

BLACK: Ultimately, the yard waste is turned into a loamy soil sought by landscapers and topsoil companies. Last year, the center turned 32,000 tons of garden leftovers into compost. This saves Pierce County valuable landfill space, but it's still not an economic proposition, and county residents subsidize the compost center. Jeff Gage says buyers won't pay as much for Purdy compost as they do for conventional materials, even when it's a better product.

GAGE: They think of peat moss as being a great product. Well, this has so many more benefits than peat moss, and they're willing to pay $120 a yard for that. Yet they're only willing to pay $20 to $30 a yard for compost.

BLACK: So for the last 6 months, the Purdy center has been experimenting with additives it hopes will boost the selling price of the compost.

(Conveyor belts)

BLACK: As the compost goes through its final screening process, it's sprayed with a solution containing microorganisms that fight disease and promote plant growth. Gage calls this step inoculation.

GAGE: It's a little bit like microbial warfare going on. We're sending in good bugs into the compost and it, and thus the customer takes the compost, puts it into their soil, where there might be plant diseases.

BLACK: Gage hopes this amended compost, as he calls it, will sell for 4 times more than regular Purdy compost. But just as important as its economic benefit to the county are its environmental benefits in places where it'll be used.

BERGER: What this would be substituting for is a chemical to kill the bacteria or the disease-ridden soil, to help modify that and bring it back to a good state.

BLACK: Elizabeth Berger is a marketing assistant with the Clean Washington Center, a state agency set up to find new outlets for recycled products. She says Pierce County's amended compost could replace some synthetic pesticides and fertilizers on farmlands, orchards, and golf courses. That could reduce the threat of harm from these chemicals to workers, consumers, and the environment.

BERGER: There's a natural demand but several of the potential end-users may not be aware of its benefits at this point.

BLACK: It's been a tough sell, even among customers who are already using regular compost, such as golf courses. Jim Snow is the national director of the US Golf Association, Green Section.

SNOW: It's a great idea and we've looked into it and we are continuing to look into that concept. But it's got a lot of practical, biological pitfalls, if you will, that could limit its potential for usefulness that way.

BLACK: For instance, Snow says it's unclear if the disease-fighting microbes in the amended compost can hold up on intensively-managed golf courses. Some pesticides would still have to be used, and he fears that those could neutralize the benefits of the compost. There are other problems, too, such as cost. While the amended compost saves money on chemicals, it requires extra labor to use, and that costs more in the short run. But pressure to reduce the use of pesticides is growing, and regulations are getting tighter. According to Olaf Ribiero, a plant pathologist who has studied the Purdy compost for 2 years, at least some potential customers recognize that.

RIBIERO: Initially, we all understand that it's going to be more expensive than just the pesticides we're using. But I think there are enough people with a vision of what the future's going to be like that they're willing to start early and take that risk and spend the extra money right now.

BLACK: Pierce County officials understand that they still have a lot to prove. But so far they think the results are good. They say the amended compost has an 85 to 100% success rate in combating diseases common in the northwest. Trials are currently underway at a Weyerhaeuser tree farm and an apple orchard. County officials hope that these tests will confirm that the amended compost is effective and help develop a technology that benefits county residents and the environment. For Living on Earth, I'm Gordon Black in Seattle.

 

 

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