February 23, 2005 | General


BioCycle February 2005, Vol. 46, No. 2, p. 44
It all started when Grandpa hauled chicken manure to vegetable farmers in the Salinas Valley, but today’s products include many variations that reach out to brewing specialized tea and fortifying vermicompost.
Karin Grobe

THE FAMILY of Don Cranford has been in the organics recycling business since 1931 when his grandfather bought a Model T truck and a shovel and hauled dairy manure to vegetable farmers in the Salinas Valley of California. Seven years later, Grandpa Cranford had a fleet of 16 trucks and a 32-man labor crew cleaning up dairies and unloading boxcars of chicken manure from as far away as Petaluma.
As area farmers moved to higher grossing cash crops, manure became a hot product. “Regional crops transitioned from low input crops like sugar beets to vegetables in the early ’30s,” recalls Cranford. “During World War II, the wives and sisters of the original crew shoveled the manure and ran the trucks. After the war, we got more mechanized. It used to take two men with shovels a full day to move 25 tons of manure. Now we do that in an hour with one man and a loader.”
Spreckles, California – where Cranford, Inc. is based – is in the heart of the Salinas Valley, which is recognized as the Salad Bowl of the World. Its temperate climate and rich soils make it an ideal growing area for cool season vegetables and wine grapes. It is also the home of the packaged salad and value-added fresh vegetable industry, with over 90 percent of the U.S. market share.
Cranford started dabbling in compost in the early ’80s. “In fact, we thought we were making compost,” says Cranford. “But looking back on it now, having experimented and learned a lot along the way, I realize we actually started making compost-quality compost, that is-in the early ’90s.”
Cranford makes three compost products. Cranford Compost, designed for organic farms and gardens, is the premium product. The feedstock is clean yard trimmings, hay, horse manure, cow manure, and lime. Some of the yard trimmings used in the compost are collected curbside in the city of San Jose. The compost is characterized by high microbial activity. During composting, it is monitored daily for temperature and moisture and weekly for carbon dioxide levels and turned when appropriate. After composting is complete, it is allowed to mature for six to eight weeks.
Cranford’s Commercial Compost is designed for conventional farms that utilize chemical fertilizers. The feedstock is clean yard trimmings. After it goes through a thermophillic stage to reduce pathogens and kill weed seeds, it is screened to a fine mesh. Micronized compost, developed in the late ’90s, is Cranford Compost ground to finer than 500 mesh. All three compost products are registered with the Organic Materials Research Institute as acceptable inputs for organic production.
Cranford also went through a learning process with compost tea. “We started making tea in 1994,” he says. “But the compost we were making in ’94 wasn’t really high enough quality to make good tea. We needed to take a couple years off and figure out how to make high quality compost as a first step towards making quality tea.”
Cranford set up his own industrial-size compost tea brewer in 1994. It included a giant tea bag and a recirculating pipe system to move the water through the bag. Custom tea application was provided to growers. “It was expensive to haul water all over California, so we’ve moved to providing tea ingredients and helping growers make their own tea on site,” he says. Cranford advises growers on building their own brewing vats. “Homemade vats cost less than commercially available brewers and are specialized to the grower’s needs,” he says.
Compost tea brewers are engineered to encourage high levels of oxygenation. “You’ve got to have oxygen to keep aerobic bacteria alive,” says Cranford. Tea ingredients typically consist of micronized compost, vermicompost, and a custom blend of specialized ingredients. Depending on the crop and the time of application, growers may want to promote proliferation of fungal or bacterial organisms, typically termed fungal or bacterial bloom.
Cranford’s current focus is learning to make quality vermicompost. “We’ve been playing with worms for two years now,” he says. “A lot of guys figure that if worms crawl through it, it’s vermicompost. We’re taking a little more conservative approach, using various feeds and running tests on the finished product.” He has also been visiting worm farms up and down the West Coast in an effort to learn from others. “I’m hoping it will be possible to micronize vermicompost to facilitate shipping it to compost tea makers all over the world,” says Cranford. “Just add water, shake and spray.”
Vegetables are the primary focus of the tea program. “We’ve found tea makes a huge difference when crops are grown on marginal ground,” Cranford says. “In a poor soil, compost tea gives a boost to plants so they can take stress better.” Most Salinas Valley row crop farmers rent their acreage and need to harvest two to three cash crops per year to make ends meet, precluding long-term investment in soil health through rotations. “Compost and tea bring the organic matter back up and promote diverse biological activity,” says Cranford. “On good ground, with a good rotation and cover cropping, the effects of tea will be much less noticeable.”
Tea application has proven successful with control of white fly and aphids on lettuce, tomatoes and other crops. “Tea application after a crop is infested has no effect,” says Cranford, “but regular applications to a healthy crop can create a hostile environment for white fly and aphids that will protect against infestation.”
Cranford is working with some golf courses to determine the effects of a regular tea program. “To safeguard customer health, they are moving towards a chemical-free environment for the fairways and greens,” he says. “Specialized ingredients to promote fungal and bacterial bloom are added to the tea. Focus is on bringing turf trouble spots up to optimum health.”
Large-scale trials with vineyards are underway. “We furnish the ingredients and they make the tea on-site,” he says. Growers have reported that compost tea applied through the drip system every ten days is helping to suppress mildew.
This article appeared in “From the Ground Up” which is funded and administered by the City of San Jose Environmental Services Department. The purpose of From the Ground Up is to disseminate information on production and use of compost and mulch to landscape, agricultural and horticultural professionals. Visit the website at

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