AugustNovember 1, 2006
News Release
Vineyards apply “custom blends” of food-scrap compost before winter rains
Adding rock phosphate and other amendments to compost process helps make key
minerals available to plant roots
Digital photos available
In the last 60 days modern compost facilities outside Vacaville and Gilroy have shipped 7,500
cubic yards (218 truckloads) of finished compost made with food scraps collected from San
Francisco and Oakland restaurants to local vineyards.
The compost, made from a diverse feedstock of kitchen trimmings and plate scrapings,
returns nutrients to vineyards and farms, stimulates microbial activity and improves soil
structure.
Now growers are taking the additional step of having the two Northern California compost
facilities blend in extra amendments such as rock phosphate, gypsum, lime and sulfate of
potash.
“By applying compost blended with specific amendments that lab tests of vineyard soils show
are needed we can tailor the compost to feed vineyards and farms nutrients they more
specifically require,” said William Brinton, who operates Woods End Research, a soil and
compost-testing lab, and advises growers on compost recipes and soil requirements.
“Mixing amendments into finished compost is a very practical and logical way to deliver
organically approved materials to the soil in the right proportions at one time,” Brinton said.
The two compost facilities – Jepson Prairie Organics outside Vacaville and South Valley
Organics outside Gilroy – make Four Course Compost from restaurant food scraps, store
additional amendments on site and mix custom compost blends to vineyard managers’
specifications.
Blending rock phosphate into compost, called “rock composting,” is an extra step that most
compost operations will not take but is highly beneficial to growers, said soil scientist Bob
Shaffer, of Soil Culture Consulting in Glen Ellen, California.
The phosphate comes from a mine in Florida. “It is very high in quality, a pure source of
phosphate particles,” Shaffer said.
Microorganisms and humic and folvic acids in the compost “pre-digest” the phosphate; that
action makes the essential mineral more available to plant roots and increases nitrogen
retained in the compost, Shaffer said.
Adding phosphate also provides calcium, iron and trace elements.
“Plants respond to this very well,” Shaffer said.
Every harvest removes nutrients from the soil. Nutrient-rich compost returns nitrogen,
phosphorus, potash, and organic matter to vineyards and farms and gives growers a natural
alternative to chemical fertilizers.
The finished compost encourages leafy growth and succulence, promotes a strong root
system and builds disease resistance. Blending in amendments at the compost facilities also
saves growers the time and expense of doing it in the field.
More than 100 vineyards and several organic farms have applied truckloads of the rich soil
amendment. Many are rushing to apply the soil amendment before the winter rains begin.
The Organic Material Recovery Institute (OMRI) of Eugene, Oregon has a process to approve
specific natural amendments based on review of the ingredients and the composting
methods. OMRI has approved Four Course for use on organically certified farms.
More than 2,000 restaurants in San Francisco and Oakland and thousands of city homes
provide food scraps to the program. Sunset Scavenger and by Golden Gate Disposal &
Recycling, operating companies of Norcal Waste Systems, Inc. collect 330 tons of
compostable material a day.
The scraps are transported to Jepson Prairie Organics and South Valley Organics, compost
facilities owned and operated by San Francisco-based Norcal. Compost workers screen,
grind, compost and cure the material using modern composting equipment and techniques.
The end products include Four Course and associated blends of nutrient-rich, finished
compost favored by Northern California vineyards and organic farms.
"This is our busiest time of year," said Robert Reed, spokesman for Jepson Prairie Organics
and South Valley Organics. “The growers want to get this compost on their vineyards and
fields now because the rain will carry the nutrients into the soil to feed plant roots, and the
compost will help soil retain water.”
Web site: www.FourCourse.com
Media Contacts:
William F. Brinton, Ph.D.
President
Woods End Laboratories, Inc
290 Belgrade Road P.O. Box 297
Mount Vernon, ME 04352
(207) 293.2457
will@woodsend.org
Bob Shaffer
Soil Culture Consulting
Glen Ellen, CA
(707) 953-5153
soilculture@aol.com
Kathleen Inman
Inman Family Wines
Olivet Grange Vineyard
Russian River Valley (Sonoma County)
(707) 395-0689
(707) 235-2071, cell
kathleen@inmanfamilywines.com
Linda Hale
Supervisor
Madrone Vineyard Management
776 Madrone Road
Glen Ellen, CA 95442
Office: (707) 996-4012
Cell: (707) 975-9374
mvm@vom.com
Robert Reed
Jepson Prairie Organics (Dixon, CA)
South Valley Organics (Gilroy, CA)
(415) 875-1205
(415) 606-9183, cell
rreed@sfrecycling.com