Benefits of Compost Tea

8/9/2019 Benefits of Compost Tea

1/32

provided information to farmers that helped thembecome more economically viable while practicinggood stewardship of the land. But after a successfuleight years, MISA is in trouble; its creative leadershipin sustainable agriculture may be crippled, becausethe key to MISAs success is also the key to its cur-rent conflict with the University administrationitsstructure and governance. MISA was established as aunique partnership between the College of Agriculture, Food and Environmental Sciences(COAFES) and the Sustainers Coalition, a group of organizations advocating sustainable agriculture. Thispartnership has shared an unprecedented cooperative

arrangement in MISAs man-agement.

The Founding of MISAIn 1987, five community organizations joined forces toform the SustainersCoalition, for the purpose of overcoming the University of Minnesotas resistance to sus-tainable agriculture researchand education. The coalitionincluded the OrganicGrowers and Buyers Association, Minnesota

Food Association, Joint Religious LegislativeCoalition, Land Stewardship Project, and theMinnesota Project (today it also includes theInstitute for Agriculture and Trade Policy and theSustainable Farming Association of Minnesota).

I dont think the problem at the University is somuch active hostility to sustainable agriculture as it isa lack of information about what the critics of con-ventional agriculture are saying, journalist PaulGruchow told Ken Taylor, a leader of the SustainersCoalition, after hearing Eugene Allen, then Dean of

The land grant colleges of agriculture in theUnited States have proudly led the country along the path to an industrial food and

agriculture system, even though it has becomeincreasingly destructive to the environment andrural communities. In the midst of farm foreclo-sures in the 1980s, family-sized farmers felt ill-served by the advice of these institutions, and peo-ple began to realize that behind the successes of high yielding crops and labor efficiency on thefarm were failures: soil erosion, contaminateddrinking water, streams filled with sediment, adecline in wildlife habitat and the loss of independ-ent family farmers.

When farmers

and environmental-ly concerned citi-zens asked agricul-tural researchersand college admin-istrations to addressthese problems andlead farming to amore sustainablefuture, they weregenerally rebuffed.However, some-times they found

friendly faculty who werent happy just doingresearch to improve the profits of agribusiness. Andin some states, they convinced legislators and col-lege administrations to open the door for smallalternative agriculture programs.

Minnesota was one of those states; citizen effortsled to the establishment in 1992 of the MinnesotaInstitute for Sustainable Agriculture (MISA) whichdeveloped innovative educational and research pro-grams that are widely recognized around the coun-try. It heightened a discussion about sustainability inagriculture within the University of Minnesota and Continued on page 4

ORGANIC FARMINGRESEARCH FOUNDATION

I N F O R M A T I O N B U L L E T I N

Winter 2001 Number 9

RESEARCH REVIEWS :

Apparatus Design andExperimental Protocol forOrganic Compost Teas . . . . .9Richard Merrill and John McKCabrillo College,Soquel, CA

Effectiveness of Compost Tea Extracts asDisease Suppressants inFresh Market Crops .. . . ..16Sylvia Welke,North Okanagon Organic Ass Alberta, BC

Effect of DiseaseSuppressive Compostson Organic VegetableQuality, Compositionand Yield . . . . . . . . . . . . .21 Anusuya Rangarajan,Cornell University,

Ithaca, NY Efficient Useof Organic NitrogenFertilizers . . . . . . . . . . . . . 26 Mark Gaskell,UC-Cooperative Extension,Santa Maria, CA

Testing AlternativeParasiticides forOrganic LambProduction. . . . . . . . . . . . 29 Janet Allen,Dragon Mountain Farm,Quesnel, BC

`

OFRF News. . . . . . . . . . . . .

Policy Program Notes. . . . . 6

Technical Program Notes. . 7

In Context: Compost Teas: A Brave New World . . . . . . 8

Grants AwardedFall 2000. . . . . . . . . . . . . .32

An Experiment in Partnership:The Minnesota Institute for Sustainable AgricultureDana Jackson


2/32

ORGANIC FARMINGRESEARCH FOUNDATION

B O A R D O F D I R E C T O R S

O f f i c e r s

Woody DeryckxPresident

Bentwood FarmsMalin, Oregon

Ron RosmannVice-president

Ron & Maria Rosmann & Sons FarmHarlan, Iowa

Mary Jane EvansTreasurer

Veritable VegetableSan Francisco, California

Ingrid LundbergSecretary

Lundberg Family FarmsRichvale, California

`

Helen AtthoweBiodesign

Missoula, Montana

Roger BlobaumBlobaum and Associates

Washington, DC

Jerry DeWittDepartment of Entomology

Iowa State University Ames, Iowa

Tom DobbsDepartment of Economics

South Dakota State University Brookings, South Dakota

Lewis GrantGrant Family Farms

Wellington, Colorado

Cynthia HizerHazelbrand Farm

Covington, Georgia

Betsy LydonEnvironmental Grantmakers

AssociationNew York, New York

Doug OBrienOBrien ConsultingSanta Cruz, California

Stephen PorterPorter Farms

Elba, New York

J.B. Pratt, Jr.Pratt Foods, Inc.

Shawnee, Oklahoma

Marianne SimmonsOnion Creek Farm

Dripping Springs, Texas

I N F OR M A T I O N B U L LE T I N

2

2001 An Organic Odyssey

Now is a time of transition in many areas of our world, and organic is certainly one. We are enter-ing a new era in organic marketing with theUSDAs recently released final Organic Rule.Overall the future looks promising for organicfarmers and consumers, but serious threatsremain in relation to GMO contamination andliability, costs to small farmers, and concentrationin the growing organic industry.

OFRF is gearing up to face these challenges as wecontinue to pursue our purpose: the improve-ment and widespread adoption of organic farm-ing practices. For us, it is also a time of transitionfrom our first decade of work to our second. As we pass this milestone, the OFRF Board of Directors is undertaking a major strategic plan-ning effort, with the goal of refining our visionand mission for the next five years. The JessieSmith Noyes Foundation has generously con-tributed $7,500 in support of this important work to prepare OFRF for the future.

The Strategic Planning Committee leading thisprocess includes three current board members,Vice PresidentRon Rosmann , Research &Education Committee Chair Jerry DeWitt , andMarianne Simmons ; two former board mem-bers, SARE National Program Director Jill

Auburn , and OFRF Founding President Mark Nielson; and two staffers,Bob Scowcroft andDon Burgett . Long-time nonprofit professionalDoug Ford is helping to ensure the success of the groups work by advising on the process andfacilitating communications. With luck and a lotof thoughtful work, the Committee will present adraft strategic plan to the Board at its Spring2001 meeting.

More Staff, New Digs, and the Supportto Make It Possible

To meet the growing demands on our programs, we have added a part-time Policy Assistant to ourstaff. (Former Program AssistantRebecca King isfilling this role for us until we hire a permanentstaffer this March!) This position will help Policy Program Director Mark Lipson address policy issues in greater detail and broaden the reach of our policy analysis. We are also seeking an internto round out the policy team. Other new internpositions are available in our development, infor-mation and administrative programs.

Of course, with the growing workload and staff tohandle it, we have had to expand our office, too. As it turned out, we were packing up our thingsthe day after the announcement of the finalOrganic Rule, and we moved down the hall into a

space twice the size of our old one the followingday. Amazingly, and with a great deal of credit toProgram AssociateMelissa Matthewson , we nevermissed a phone call (and there were plenty!), and we were settled into the new office before the holi-days were over.

We would not be moving forward so positively without your support. Our network of organicfarmers, consumers and businesses continues togrow and give generously to our work. We are par-ticularly grateful to theClarence E. HellerCharitable Foundation for their recent two-yeargrant of $150,000 for general program support.The Heller Foundations trustees and staff are lead-ing advocates of more sustainable approaches toour food and farming systems, and they have sup-ported OFRF and many other worthy organiza-tions over the years.

As we deposit your contributions coming in nowin response to our year-end mailing, we are partic-ularly thankful to all of you who have sent usdonations of $10, $25 and $50. We work hard toearn your support, and we think of your gifts as we use the money day-to-day. Together with thesupport of those who have chosen to give $100,$500 and more, we have already received morethan $30,000 from our year-end appeal.

O F R F S T A F F

Bob ScowcroftExecutive Director

Don BurgettDevelopment Assistant &

Information Services Coordinator

Rebecca KingPolicy Program Assistant

Mark LipsonPolicy Program Director

Melissa MatthewsonProgram Associate

Laura RidenourEvents Coordinator

Jane Sooby Technical Program Coordinator

Erica WalzEditor, Information Bulletin

Coordinator,National Organic Farmers Survey

OFRF NEWS


3/32

3

W I N T E R 2 0 0 1 N U M B E R 9

I N F O R M A T I O N B U L L E T I N

Erica WalzEditor/Typographer

WoodyDeryckx, Helen Atthowe, Cynthia HizerEditorial Advisors

Dianne CarterIllustration

PRINTED BY Community Printers

Santa Cruz, CA

The Information Bulletin is published by the Organic FarmingResearch Foundation, a non-profit foundation dedicated tofostering the improvement and widespread adoption of organicfarming pra ctices. Our mailing address: P.O. Box 440, SantaCruz, California 95061, telephone: (831) 426-6606, fax: (831)426-6670, email: , web: www.ofrf.org. Materialin this publication may be reprinted with credit.

Research Reviews are the results of OFRF-funded research andeducation projects. Project reports presented in this newsletterare derived from materials submitted to OFRF by project coor-

dinators. These research and education projects may be sole-ly supported by OFRF, or may involve other sources of support.Acknowledgment of all project contributors and cooperatorsis provided, wherever possible. For further information on theseprojects, you may contact OFRF or the growers andresearchers listed with each review. The use of trade names orcommercial products published in these results does not con-stitute any product endorsement or recommendation byOFRF.

OUR MISSION To sponsor research related to organic farmingpractices To disseminate research results to organic farmersand to growers interested in adopting organic production sys-tems To educate the public and decision-makers aboutorganic farming issues

Printed on recycled-content paper. Please recycle.

We also greatly appreciate the companies who each have contributed $1,000 ormore to our work since last summer:

Brown-Forman CorporationCascadian Farm / General MillsCelestial Seasonings / Hain GroupCF FreshEarthbound Farm /

Natural Selection FoodsEpic Roots, Inc.Fetzer VineyardsThe Lark Creek InnNew Hope Natural Media Paul Newman / Newmans OwnNewmans Own Organics

Tanimura & Antle Veritable Vegetable Whole Foods Market Wolavers / Panorama Brewing Co. Working Assets

Notable Events!

OFRF Events Coordinator Laura Ridenour has had her plate full this fall,toousually with delicious organic food! August brought a great thrill to ourNorthern California friends, as Grammy Award-winning singer-songwriterTracy Chapman performed a concert to benefitOFRF and the UCSC Center for

Agroecology & Sustainable Food Systems Farm & Garden

Apprenticeship Program . Tracy alsostopped by our pre-concert dinner tothank everyone for supporting organicfarming! She also took time on stage totell the whole crowd about the importanceof organic agriculture and describe howshe had started gardening organically as alittle girl. The dinner was an all-organicfeast prepared by famed local chef JesseCool of Flea Street Caf, making theevening delicious as well as memorable.

Following on the heels of the concert,OFRF held its Eighth Annual FallOrganic Benefit Luncheon at the Lark Creek Inn in Larkspur, CA. Sponsoredagain by Whole Foods Market , the meal was a culinary collaboration of five greatchefs. It was wonderful to hear lead chef

John Mitchell note how far we have come

in the eight years since this annual eventbegan. Finding the ingredients for a com-pletely organic gourmet meal was very dif-ficult in the beginning, but this year hesaid they had no problem tracking downeverything they needed, from cooking oils,to spices, to organic chicken. The organicindustry has come a long way, indeed!

In December, Executive Director BobScowcroft spoke at theTenth AnnualEnvironmental Media Awards in Los

Angeles. Hosted by the Environmental

Media Association (EMA), the event hon-ored outstanding film and TV work focusedon environmental issues. Organic food andfarming was the theme of the evening, withthe venue decorated in the style of a farmers'market, including stalls of produce allaround the dining area. The 700 industry attendees were treated to an all-organic mealprepared by top Los Angeles chefs. Chef andlong-time OFRF supporter Donna Prizgintas coordinated the meal, and herstatement: "Eating is an environmental

activity," became the underlying theme of the event.

OFRF Receives Gift of PrimeInternet Real Estate!

In another first for us, Internet commercecompany WebMagic, Inc. has donated anonline domain name to OFRF. The unso-licited gift of Organically.com was valuedat $20,000 by a domain name appraisalfirm, and represents our first major virtuagift! We are glad that WebMagic CEOGreg McLemore identified us as a worthyrecipient for the domain and thank himfor the generous gift. OFRF does not cur-rently plan to use the domain name itself (we like our ofrf.org), and we invite any-one interested in acquiring the domain tocontact us (Don Burgett or BobScowcroft) at (831) 426-6606.

Looking ahead, Laura and the rest of thestaff have their hands full. TheInaugural

Assembly of the Scientific Congress onOrganic Agricultural Research (SCOAR) will take place in January in Pacific GroveCA, in conjunction with the 21st annualEcological Farming Conference. Fundsfrom the USDAs Initiative for Future Agriculture and Food Systems (IFAFS) arsupporting SCOAR as part of the work of

the Organic Agriculture Consortium of OFRF and Ohio State, Iowa State, NorthCarolina State and Tufts Universities.

Next up will be Organic Day at the annualNatural Products Expo-West in Anaheimin March. This year, the usualOFRFOrganic Benefit Luncheon will moveinside the main pavilion, where we expectto serve up to 500 people an all-organicgourmet lunch. This will be more thandouble the attendance of our previous Expluncheons! Expo organizersNew Hope

Natural Media wanted to increase our visibility at the Expo and encourage more of the retailers attending Thursday workshopsto experience what an organic meal can beChefs Donna Prizgintas and ChrisBlobaum will preside over the meal againthis year, so it is sure to be outstanding.

We hope you can join us for some of thefestivities, and we wish you a relaxing witer and an early start to your season!

Don Burgett


4/32

COAFES, admit that he was not familiar with Wendell Berrys writing. This motivat-ed the Sustainers to propose a series of sem-inars in 1988 between university faculty andmembers of the Coalition, and theUniversity agreed to participate. A joint task

force continued the dialogue, and exploredpossibilities for initiating a program of research and education in sustainable agri-culture. A lengthy process ensued untilfinally, in 1992, the first MISA Board of Directors was named, and by-laws weredrawn up and approved by the University administration and legal advisors. Richard Jones, then COAFES Dean, committed$200,000 for the first year and $300,000per year to support MISA efforts for thenext four years.

One of a KindMISA is a unique entity; its not a collegedepartment, nor a sustainable agriculturecenter, such as those at the Universitiesof Wisconsin, Nebraska, Washington orthe University of California-Santa Cruz,nor a program, like the one at theUniversity of California-Davis. It wasntestablished by state statute as was Iowas Aldo Leopold Center. MISA is a joint ven-ture, a partnership, hard won after fouryears of trust building, structured dialogueand negotiation between advocates for sus-

tainable agriculture and family-sized farmsand the COAFES faculty and administra-tion. It is governed by a fifteen-memberboard of directors, seven of whom must besustainable agriculture farmers. Nine mem-bers are nominated by the Sustainers, andsix are nominated by the University.

All other university programs in sus-tainable agriculture that involve citizensplace them on advisory committees, noton decision-making boards like MISAs.The past two deans of the COAFES strug-gled with this relationship because theUniversitys hierarchal structure doesntoperate in terms of dialogues, collabora-tions or partnerships, especially with farm-ers or staff of non-profit organizations.However, though uncomfortable withMISAs independence, the deans came torealize the advantages of having good rela-tionships with MISAs constituency and itsfriends in the state legislature.

MISAs AccomplishmentsMISA has leveraged its yearly base budgetfrom the College to bring over $8 millionto sustainable agriculture endeavors inMinnesota over the past eight years. Aboutone-fourth to one-third of the funds from

the College were spent on a competitivegrant program for multi-disciplinary research. MISAs Program Committeemade grants to build research teams thatincluded farmers, university researchers,non-profit organization staff and agency professionals. Recipients raised additionalfunds from private foundations, the USDA Sustainable Agriculture Research andEducation program, and the MinnesotaLegislative Commission on MinnesotaResources; thus additional dollars werefunneled back into the University forresearch and outreach.

MISAs many other accomplishmentsinclude the establishment of a graduateminor in sustainable agriculture and a very unconventional endowed chair in agricul-ture systems, both guided by committeesthat include representatives of the commu-nity as well as faculty. The endowed chairprogram is called a revolving bench by itsfounders, because two or three people cansit in the chair at one time. Over a threeyear period the chair has been filled witheight individuals, including two farmersand two community organizers.

Special appropriations from theMinnesota Legislature also extended MISAsreach. In cooperation with the MinnesotaDepartment of Agriculture, MISA createdan information exchange that advisesandlearns fromfarmers and the general public.

Organizations in the Sustainers Coalitionlobbied the legislature for funds to form fiveRegional Sustainable DevelopmentPartnerships that provide rural communitiesdirect access to University resources to buildtheir economies on sustainable principles.Farmers working with the Sustainers alsoconvinced the Legislature to fund a new fac-ulty position and facilities for an AlternativeSwine Systems Program. MISA received thefunds and established an Alternative SwineSystems Task Force that included farmers as

well as faculty from the Animal ScienceDepartment. Today, swine research is goingon in hoop house structures at the WestCentral Research Station in Morris,Minnesota.

The ConflictMISA was accumulating successes andincreasing its capacity to advance sustain-able agriculture when President Mark Yudolf hired a new Dean for the Collegeof Agriculture, Food and EnvironmentalSciences in 1999. Straight out of the pharmaceutical biotechnology industry, DeanCharles Muscoplat repeatedly declared thhis goal for the College was to develop anpatent a gene in soybeans that could curecancer. MISA constituents could see thathe was unfamiliar with the concepts of su

tainable agricultural systems.In January 2000, Dean Muscoplat

announced that all the centers housed inthe College would have to accept budgetcuts and undergo a faculty review to detemine if they should continue or be termi-nated. MISA, not a center, had already undergone an outside review of its first fiyears, according to its by-laws, butMuscoplat ignored this process and its recommendations. Don Wyse, MISAs execu-tive director, worked to build a good rela-tionship between MISA and DeanMuscoplat, but the new dean didnt seem

to understand what MISA meant by sus-tainable agriculture, nor the nature of community involvement in the Institute. Although he could successfully transitionfrom the corporate boardroom to the hier-archy of university administration, he did

not fathom how to work with a partner-ship that gave decision-making powers tosmall family farmers, non-profit organization staff and faculty members on theMISA board.

In April, 1999, Muscoplat forced theresignation of Don Wyse, because of philosophical differences, without con-sulting the Board of Directors. Friends ofMISA were outraged; more calls and letteof protest poured into the university administration than had ever been seen

4

I N F O R M A TI O N B U L L E T I N

Continued from page 1

Before MISA, the College wasnt even acknowledgingsuch a thing as sustainable agriculture.


5/32

MISA Today The MISA office is still open, the website(www.misa.umn.edu) is active, board meet-ings are held, students continue to holdtheir Whats up in Sustainable Agriculturebrown bag seminars, but according to GregReynolds, a MISA board member andorganic vegetable farmer from Delano,Minnesota, there is a feeling of beingstuck. He thinks that the basic problem isthat MISAs vision is not the Deans visionfor agriculture.

Firing Don Wyse was not an acci-dent,Greg told me, but a deliberate actbased on where the College should go. The

only reason the Dean has ever given is that

he had a philosophical difference withDon. Now the University is dragging itsfeet in settling this, because they dontknow how to deal with community.

Carmen Fernholz, an organic grain andlivestock farmer from Montevideo, whochaired the MISA board from 1992 to1998, is afraid that there is a deteriorationof the friendly environment for sustainableagriculture that MISA created. BeforeMISA, the College wasnt even acknowledg-ing such a thing as sustainable agriculture.There were a few strong souls on the facul-ty, but they were afraid to step forward. InMISAs peak time, the College was gettingnew staff and researchers who wanted tomake agriculture more sustainable.

This is not to say that COAFES becamedevoted to sustainable agriculture; faculty advocates for sustainable agriculture are stillin the minority. But MISA did attract sus-tainability-minded students and faculty tocampus. And new faculty does make a differ-ence. Carmen and I recalled a MISA boardvisit in 1995 to the Lamberton Research andOutreach Station in southwest Minnesota, where the board was shown a field of soybeansdotted profusely with cockle burrs and toldthat it was an experiment in organic produc-tion. It was pitiful, a typical example of con-ventional researchers studying a field of soy-beans with no chemical inputs, but not study-ing an organic production system.

You wouldnt recognize those researchplots now, Carmen told me. With theaddition of two faculty members dedicatedto doing effective research on organic farm-ing, the station now has an entirely different

5

W I N T E R 2 0 0 1 N U M B E R 9

before. The MISA Board asked the Dean tomeet with them, and he did, attended by two campus police officers who stood out-side the door while the board chair, SisterMary Tacheny, from the School Sisters of Notre Dame, facilitated the meeting. DeanMuscoplat talked unconvincingly about hiscommitment to sustainable agriculture, andit was clear that he expected the board toaccept the situation and wait for a reviewby the College to learn MISAs future. Heclaimed that MISAs authority as laid out inthe by-laws to hire and fire an executivedirector was invalid and refused to reinstateDon Wyse.

The Sustainers felt they were almost

back to square one, but they sent represen-tatives to meet with Dean Muscoplat andother administrators in May to start a dia-logue, and agreed to continue meeting togain a better understanding of each otherspositions. Now, seven months later, they arestill meeting. Muscoplat has insisted thatMISAs unique structure will not work,though it was approved by the University administration in 1991 and worked foreight years prior to his employment at theCollege. The MISA board refused toapprove the hiring of a new executive direc-

tor, asserting that they had not dismissedDon Wyse, but did accept the appointmentof an acting administrator, to assumesome of Dons responsibilities. As of this writing, there appears to be a proposal onthe table for a by-laws amendment settingup a joint oversight committee with equalrepresentation from the University and theBoard to handle personnel functions.

If negotiations on this proposal can pro-duce a settlement, it would be a happy firststep, but other problems remain. Last spring,MISA learned that its base funding from theUniversity could be cut significantly or com-pletely removed. Dean Muscoplat has offeredto help raise grants and contributions forMISA, but the Sustainers insist that COAFEScommit basic funds to MISAs budget onbehalf of the public. Statements by DeanMuscoplat in reference to the management of MISAs grants program and the endowedchair program cause concern amongSustainers who fear he may attempt to over-ride the committee process and gain controlover how those funds are spent.

research agenda. Lamberton researchers alooking at how to restore crop diversity tothe region, and the rotations necessary toan organic system fit their research agend well. Carmen, who serves on the ElwellFarm Ecology Board, a research focus of the Lamberton Station, credits the influ-ence of Don Wyse and the friendly envi-ronment for organic agriculture that MISAcreated for the turnaround at theLamberton station.

MISA Tomorrow? What has made MISA such a vital forcehas been the involvement of a constituencin its conception, development and governance. MISA founders insisted that theorganization exist outside the mold of tra-ditional land grant college programs, and

not be guided by conventional agricultureminds. Sustainers Coalition members havvigilantly monitored its program grants,publications and the development of regional partnerships so that MISA reachout beyond the audiences land grant col-leges have come to serve and connected with those the land grant colleges wereestablished to serve.

MISAs founders thought they had buiprotection into the by-laws that would prevent its dismantling. But a new dean washired who first disregarded the by-laws,

then declared them unworkable, and hehas been backed by the University President. However, MISA is backed by atenacious grassroots constituency. In spiteof the toll it is taking on individual organizations to have their executive directorsspending so much time in negotiations with the University, the Sustainers are notgiving up. This is how MISA was createdThis is how sustainable agriculture advo-cates in Minnesota will keep it alive.

To follow events as they unfold, visit

www.sustain.org/MISAfriends.

Dana Jackson is the associate director oStewardship Project, an 18 year old Minnesota-based organization that fostethic of stewardship for farmland and pmotes sustainable agriculture and sustacommunities. Dana served on MISAs Bof Directors from 1994 through 1999 astill a member of MISAs Endowed ChCommittee and the Graduate Minor Committee.

You wouldnt recognize those research plots now.


6/32

6


will be available. Check our website formore information at www.ofrf.org, whereyou can also find information aboutbecoming a SCOAR participant.

USDA Highlights Meanwhile, back in Washington, finalUSDA appropriations for the 2001 fiscalyear emerged with a little bit of new money for organic research and education.$500,000 has been allocated for a new com-petitive grants program dedicated to organ-

ic transition. OFRF has commented toUSDA on how the program should bedirected. The USDA-SARE program got itsfirst real increase in years, with a boost of about $2 million dollars to a total of about$13 million. SARE is funding a growingnumber of organic projects, and this increasein funding should help continue that trend.

Of course the overall situation at USDA will be in turmoil as the new administra-tion takes the reins. Ann Veneman, thenew Secretary of Agriculture, has somefamiliarity with organic agriculture fromher stint as the head of CaliforniasDepartment of Food and Agriculture. Webelieve that organic farming is basically anon-partisan phenomenon, and hope toconvince Secretary Veneman that it isimportant to nurture its further growth.

Agricultural Biotechnology ProgramIn recent months, a major focus of ourPolicy Program has been agriculturalbiotechnology and genetic engineering. As

a member of the USDAs Advisory Committee on Agricultural Biotechnology,I have been active in representing the ques-tions and concerns of organic farmersregarding the use of genetic engineering inagriculture. Weve partially succeeded ingetting our concerns on the table and intothe general debate, but thats about as faras it goes. In the context of the Starlink debacle, where GMO corn deemed unfitfor human consumption found its way into numerous commercial food products,

farmers generally are getting the short endof the stick and organic growers are cer-tainly not an exception.

OFRF Board and staff are now finalizinan organizational policy statement on agricultural biotechnology, which will be avaiable on our website shortly. In overview,OFRF feels that genetic engineering tech-nologies may ultimately have useful potential, but we have grave objections to the ways in which it is being developed,employed, and regulated at present. Webelieve that conditions for the safe andeffective use of organisms modified by genetic engineering (GMOs) for agricultual applications are not currently in place.This includes the inadequacy of scientificunderstanding about GMOs in the envi-ronment and the food supply, as well as th

shortcomings of the U.S. government regulatory system for these products.OFRF believes that the profitability of

farming and food security will bothimprove without genetic engineering if farmers and researchers put much moreeffort toward developing ecologically sustainable systems. Therefore, the OrganicFarming Research Foundation generally opposes the use of genetic engineering inagriculture at this time.

Policy Program Notes by Mark Lipson, Policy Program Director

New Organic Consortium As we reported in the last issue of theInformation Bulletin, OFRFs ScientificCongress on Organic Agricultural Research(SCOAR) has received funding from theUSDAs Initiative for Future Agricultureand Food Systems (IFAFS) as part of a con-sortium with Ohio State, Iowa State, NorthCarolina State and Tufts Universities. ThisOrganic Agriculture Consortium isanother first in the progression of newinstitutional attention to the needs of

organic growers.The $1.8 million awarded for the multi-

year Consortium is certainly the largest sin-gle grant award ever made for organicresearch and education. Its also the firsttime that multiple land-grant universitieshave collaborated on a set of organic proj-ects, and it is the first significant federalgrant money that OFRF has pursued forour own work. OFRFs portion of theConsortium proposal was funded at$220,000 over two years for activities of the SCOAR project. These funds will sup-port OFRF staff time and pay for farmersto travel to SCOAR meetings.

Inaugural SCOAR Meeting SCOAR is a nationwide effort to stimulatescientific dialogue about organic agricultureamong working organic farmers, researchscientists, and agriculture information pro-fessionals. Its mission is:to plan and pro-mote research and information exchange for understanding and improving organic agri-cultural systems .

On January 23 and 24, OFRF will hostthe first national SCOAR meeting at the Asilomar conference center in PacificGrove, CA. This meeting will be an oppor-tunity for over 100 producers, researchers,and information-management professionalsfrom around the country to come togetherand share their experiences about on-farmorganic research. Meeting participants willrefine SCOARs objectives and begin devel-oping a national agenda for organic farm-ing research. A transcript of the meeting

Another flash update on...

These Exciting Times in Organic Research Policy

ACTION ALERT!

The USDA has released a request for publiccomments as a part of its biotechnology ini-tiative. The request can be found in theFederal Register, November 30, 2000,p.71272-71273, and the deadline for com-ments is February 28, 2001. The request ison the subject of marketing of genetically engineered food products, as well as therelated issues of product segregation andidentity preservation. This is in advance of any rulemaking and offers an opportunity to

let the USDA know what issues are of con-cern to the public and the agricultural indus-try. This is a very important occasion for theorganic farming sector to voice its opinionsabout how the USDA should proceed withthe regulation and marketing of GMOs inthe foodchain. Please see the OFRF websiteat http://www.ofrf.org/policy/index.html formore information about this request forcomments.


7/32

7

W I N T E R 2 0 0 1 N U M B E R 9

T hree years ago, OFRF Policy Program Director Mark Lipsonpublished a groundbreaking study,Searching for the O-Word , which scouredUSDA research projects for those relevantto organic producers. Of 34,000 projects,the study found only 34 that had strongrelevance for organic producers, or 0.1%(one-tenth of one percent).

This past year, Ive been doing a follow-up study, identifying specific organicresearch projects and information sourcesat land grant institutions across the coun-try. Ive considered calling it Needle in aHaystack, since the information is sosparse and dispersed.I have found that only 131out of 885,800 total research acres are certified organic and being used for organic farming research.This works out to0.01%, or one-hundredth of one percent,of the total. Another 206 organic researchacres are not certified, and 239 acres are intransition to certified status.

There are notable organic research pro-

grams at the land grant level inMinnesota, Iowa, Ohio, North Carolina,and West Virginia. Many of these pro-grams are taking a systems approach,involving growers at the decision makinglevel and using interdisciplinary researchteams. Here are some details:

University of MinnesotaSt. Paul, Minnesota

Eighty acres of the Elwell Agroecology Farm are certified organic. Elwell is part

of the Southwest Research and OutreachCenter in Lamberton (noted in our fea-ture article). Organic rotation plots wereestablished in 1990 and a comparisonstudy has been done since 1989.Researchers Elizabeth Dyck and PaulPorter are also managing the OrganicConversion Project that works to connectfarmers converting to organic with men-tors and simultaneously collect data onthe conversion process.

North Carolina State University Raleigh, North Carolina

The Organic Unit within the Center forEnvironmental Farming Systems (CEFS)had 80 acres certified prior to being flood-ed by two hurricanes in three years. Theproject has been moved to higher groundand organic certification is pending for100 acres on a research station inGoldsboro. Numerous interdisciplinary research projects are being done, including

a significant transition study that is com-paring six organic transition strategies.Long-term cropping systems studies arealso being established. According toresearcher Nancy Creamer, plans are toconduct comparative systems research for

perpetuity. An advisory committee thatincludes farmers oversees the research. A 7-

acre demonstration organic farm has beenestablished at which an intensive summerinternship program was held for the firsttime in the summer of 2000.

Ohio State University Columbus, Ohio

A multi-disciplinary long-term study onthe transition to organic was started in2000. After the transition period, thestudy area will be devoted to purely organ-ic research. Thirty-five acres of the 164-acre West Badger Farm in Wooster are des-ignated transitional to organic in fieldcrops. Five acres will be used for organicvegetable research at Fry Farm. Nine acres will be certified organic. Project coordina-tor Deb Stinner has planned trials with themarket in mind. There were nine studiesin the ground in 2000, the major effortbeing a large-scale transition study. Anadvisory group comprised of growers andresearchers makes budgeting, research pri-ority, and research design decisions.

Iowa State University Ames, Iowa

Kathleen Delate, assistant professor inorganic agriculture/horticulture, holds thevery first academic appointment in theU.S. specifically to study organic practiceDelate maintains designated organicresearch sites at 5 research farms andintends to certify all sites (one became cetified organic in 2000). Delate has 13 triacurrently, including a project comparing

the agroecology and economics of organiand conventional corn, soybeans, oats, baley, alfalfa, red clover, green peppers, brocoli, and medicinal herb production.Farmers assist in setting research prioritiesthrough focus groups and annual meetings.

West Virginia University Morgantown, West Virginia

The 60-acre Horticulture Farm has the dis-tinction of being the only research station inthe United States being transitioned entirelyto organic. An interdisciplinary transitionstudy began in fall 1999, when the entirefarm started to be managed organically. A major transition study is being done as wellas work on apples, pears, grapes, and blue-berries. According to director James Kotconthe ultimate goal is to maintain the farm asan organic research farm. Advised by a committe of organic growers, researchers are

comparing the organic transition in both amarket garden and field crop/livestock farmThe crop/livestock farm will also comparepresence and absence of animals in the sys-tem.

The full report covers organic farmingresearch activities in all 50 states.State of the States: Organic Farming Systems Research at Land Grants 2000-2001 , isavailable for a requested donation of $5 ofree through the OFRF website www.ofrf.org.

Technical Program Notes by Jane Sooby, Technical Program Coordinator

Needle in a Haystack Searching for organic farming research at land grants

Though certified organic acreage represents only a tiny fragment of the total research area, the organic-dedicated programs that do exist are fascinating and inspiring.


8/32

8


In this issue of the Information Bulletin wepresent the results of two compost tearesearch projects. The first, by Richard

Merrill, looks at designing and operatingan aerated or active compost tea appara-tus. The second, by Sylvia Welke, field testsa variety of compost tea extracts, producedby passive methods, which generate a lessoxygenated tea mix. These reports helpillustrate that there are many differentopinions out there about compost teas:how they should be made, which varietiesto produce for which crops and for variousintended outcomessuch as disease sup-pression or a source of plant nutrientsand how effective teas are in the field.

To tea or not to tea Anecdotal evidence suggests that not a lotof growersorganic or otherwiseare uti-lizing teas. Producing teas on a fieldscaleespecially aerated teascanrequire a significant initial investment(depending on how you go about it), butperhaps more important, a commitment todeveloping a reliable protocol and methodof making observations. Key monitoringtools, such as pH and CO2 meters and athermometer can help, but a relationship with a good laboratory and a microbiolo-gist might be needed to (begin to) makesense of the outcomes.

Nonetheless, compost teas are beingexplored enthusiastically by a number of farmers and researchers, whoyou guessedithave a variety of opinions about pro-ducing and using them. Carl Rosato, anorchardist in the Sierra foothills, is devot-ing significant time and resources to teason his farm, and at this point is committedto aerated teas. (His early tea research was

reported in Information Bulletin1:Controlling Peach Brown Rot.) Yet hefinds his research ideas and methods devel-oping slowly as he figures things out alongthe way. For example, his trials attemptingto control brown rot with teas were incon-clusive, yet he feels he can definitely pro-duce a nutritive effect in his peach orchardsusing a compost tea soil drench. He thinkshe has successfully made peaches sweeter with a tea drench complemented with sul-fur and potassium. While the additives

may have produced the greater effect, henotes that he is also getting good K in thecompost feedstock he uses.

Others who have experimented with teashave found their efficacy difficult to deter-mine. Helen Atthowe, OFRF Board member,farmer and Extension Advisor in Montana,eagerly pursued tea research following publi-cation of the first German tea studies(Weltzien et al., refer to project bibliographiesin Research Reviews). Not having consistentluck with them, she focuses now on suppres-sive compost explorations. In reviewing con-tent for this newsletter, she noted that the lit-erature cited regarding disease suppressiveeffects of compost is controversial, and may be related to initial compost ingredients. Theliterature regarding disease suppressive effectsof compost teas is even more controversial.Further, studies that document the nutritiveeffects of teas are not shown and to herknowledge have not been done sufficiently toallow prediction about what kinds of nutri-ents we can expect from compost teas made with different materials.

To air or not to air A quiet controversy persists over whethercompost teas should be produced passive-ly (without active aeration), or actively,a process which might include a bubbler, avortex nozzle, or any recirculation methodthat moves the water through the compostfeedstock. Others feel the aerated/non-aer-ated issue is overstated, and may not be asimportant as other factors.

Elaine Ingham, a tea researcher with SoilFoodweb, Inc. in Corvallis, Oregon, strongly supports the aerated approach, noting thatpassive systems can go anaerobic quickly andthat anaerobic organisms are toxic to plant

cells. At the same time, she notes that justbecause a system is passive does not meanthat it will become anaerobicit depends alot on the feedstock, the environment andthe brew time. However, she strongly suggeststhat anaerobic teas are not as helpful aerobiconesthat anaerobic by-products producecompounds that are toxic to plant cells, andthese conditions should be avoided. She sup-ports a recirculation or vortex system, becausesuch active systems push the beneficialmicrobes out of the feedstock and into the

tea substrate. Ingham believes this action isimportant to pull the organisms out of thesolution, although not too forcefully orthey will be macerated. Otherwise the tea will contain only the non-living nutrientand miss the desired bacteria and fungi.

However, a number of studies andresearchers suggest that anaerobic teas mayhave greater disease suppressive capabili-tiespossibly due to the biocidal effects othe unpleasant by-products they create, orbecause the desired beneficial organismsarepresent in the extracts. Sylvia Welke inves-tigated the potential for disease suppressionof an anaerobic tea based on WillBrintons (Woods End Laboratory, Mt.Vernon, ME) suggested protocol for mak-ing a tea without active aeration, otherthan occasional stirring.

Will Brinton finds the discussion of aero-bic teas vs. anaerobic teas problematic. Hebelieves that neither method represents a silver bullet; that nature is not that simplistic.Studies have shown that facultative anaer-obes are the bacteria doing the work of dis-ease suppression, yet by definition, they malive in aerobic or anaerobic conditions, andhave the ability to survive in low-oxygenenvironments. Standing, unaerated solutionshave been shown to have extremely highcounts of facultative anaerobes.

Taking the plungeBrinton suggests that for those who wantto try teas for disease suppression, to firstidentify the disease youre trying to controland conduct a thorough review of the liter-ature. Has the organism youre seeking tocontrol ever been successfully controlledusing teas, and if so, what was done? If yousend a sample of your tea to a lab foranalysis, look at bacteria counts and themix of organisms, and check whether thoseorganisms have been shown as effectiveagainst your disease. And realize, too, that weather and environmental conditions willaffect the efficacy of a tea. A tea that per-forms well under one set of conditions maynot be as effective when those conditionschange.

Dont be afraid to experiment with com-post teas. But rather than look for simpleexplanations, be open minded to the vari-ety of possibilities, and as Brinton says,review all of the literature and the contra-dictions, and embrace that.EW

In Context

Compost Teas: A Brave New World


9/32

9

RESEARCH REVIEW

W I N T E R 2 0 0 1 N U M B E R 9

Interest in organic teas for use in agri-culture and horticulture has grownrapidly during the last decade. The lit-erature and internet web sites are full of experiments, testimonials and observations which suggest that certain liquid extrac-tions of manures or composts, at variousstages of decay, can supply plants with atleast four major benefits: a source of plantnutrients; a source of beneficial organiccompounds, an ability to suppress certainplant diseases; and as a way to build soilstructure when applied as a drench.

In preparing for this project wereviewed some of the pertinent researchconcerning organic teas, and noted thatthe results of studies on the effects of suchteas, especially as a biocide, is quite mixed. We believe this is due to the variablenature of both the organic feed stock andthe methods of extraction. We make somesuggestions concerning a protocol for on-site research into the production and useof organic teas with suggestions for con-

trolling feedstock and extractor variablesin field experiments. Finally, we describeour experiences with a simply-made, aero-bic organic-tea extractor prototype. Ourresults confirm those of others: so-calledanaerobic tea systemsthose in whichorganic stock is simply soaked in waterare actually aerobic for the first 48 hoursor so of extraction. After that, they become anaerobic. In other words, aerated

or aerobic systems simply extend the timeof useful extraction by replacing or addingoxygen into a system that would otherwisego anaerobic. It should be the goal of allorganic tea extraction methods to avoidanaerobic conditions.

Project Objectivess To test the design and operation con-

sistency of an organic tea apparatusin search of an inexpensive extractordesign prototype that will produceexpected microbial populations.

s To sample, test for, and document any short-term differences between aerobicand anaerobic teas in the CabrilloOrganic Tea Apparatus (COTA) exper-iment and the compost feedstock.

s To establish some experimental proto-cols for future projects that will furtherdefine what is being produced in aero-bically-made organic teas.

MethodsCompost source. We located a consistensupply of near-finished compost made byGrover Environmental Products inModesto, California, a commercial com-post producer registered with theCalifornia Compost Quality Council. Thecompost is made from vegetable produce waste from supermarkets, city green wastcollection programs and materials fromtheir own landscaping business. Materialsare screened, piled in rows and processedusing a modified Lubke method. They have designed their own row-turningequipment that measures moisture con-tent and adds water as needed while turn-ing rows. Rows are monitored daily foroxygen, ammonia, pH, and temperature, which does not exceed 145 degrees F.Every 3000 yards of compost is checkedfor heavy metal content and ammoniacontent as regulated by the state wastemanagement board.Set-up. The experiment was performed inan empty greenhouse so that we couldcontrol the external temperature and environment for all of the individual tea apparatuses. Four aerobic tea apparatuses werebuilt following the plans of Model 3, adesign that incorporated spray-head and

screening improvements over earlier trialmodels. In addition, four anaerobic barrels were designed to be used alongside theaerobic apparatuses. These anaerobic bar-rels consisted of the same type of plastic,fifty-five gallon barrels used for the aero-bic units. Shade cloth sacks were sewn tohold the same amount of compost as theaerobic apparatuses. These sacks were supended in the middle of the barrels usinga length of line and a metal bar.Preparation. Two 55-gallon barrels werefilled by taking shovels of compost fromall sides of compost piles, and at differenheights and depths. These barrels werethen taken to the project site. All barrels were filled with 50 gallons of water runthrough a garden dechlorinator to reducechlorine content. Five gallons of compost were added to every apparatus, in thefeedstock container for the aerobic barrel(#1-4), and in shadecloth bags for theanaerobic barrels (#5-8).

Richard Merrill and John McKeon

Apparatus Design andExperimental Protocol for Organic Compost Teas

Project leader:Richard Merrill, Program Director, Dept. of Horticulture, Cabrillo Community CollegeSoquel, California

Student assistants: John McKeon, David Seidman, Kay Hoberecht

Experimental design support& data analysis:Marc Buchanan, Agricultural Consultant

Cooperating growers:Route One Farms, Santa Cruz

OFRF support: $4,860

Project period: 1997-1998

The Cabrillo Organic Tea Project double-barrel active tea extractor units #1-4, set upin the greenhouse. The four passive extractors (#5-8) were single-barrel units (not shown).


10/32

10


Baseline compost data. At the same time,samples of compost were collected fromthe feedstock containers of barrels #1-4.These were sent to BBC Labs in Tempe, Arizona for analysis to serve as a compari-son to the tea samples collected later at

24- and 48-hour processing times.Tea production and sampling. At 4:00pm on June 21 the four aerobic barrels were turned on and the shadecloth bags of compost were put in the anaerobic barrels.Data collection began immediately. Every two hours, excluding the hours from 12am to 8 am, we measured oxygen (O2),pH, electrical conductivity (EC), and tem-perature. Oxygen measurements weretaken with a portable O2 meter to measurethe differences in O2 levels between the

aerobic and anaerobic production meth-ods. These measurements were taken with-in the barrels at a middle depth for theaerobic barrels and at a surface depth andbottom depth in the anaerobic barrels.Electrical conductivity, pH and tempera-ture were taken with portable meters as well. Samples were extracted from eachbarrel and tested in a cup. These measure-ments were taken to establish any trendsduring production. At the 24-hour mark,tea samples were taken from all eight of the barrels and sent to BBC Labs for com-

post tea analysis.

Tea additive tests. After the 24-hour sam-ples were taken, 32 oz of sulfured molassesand 32 oz of azomite rockpowder wereadded to aerobic barrels #1-4. These sup-plements were added as a food source formicrobes that might exist in the tea to seeif there would be any population increasein the groups tested for by BBC Labs inthe 48-hour sample.

Anaerobic tank mixing. Also at the 24-hour mark, anaerobic barrels #5-8 weremixed vigorously for one minute and this was repeated every four hours up to the48-hour mark. This was done to docu-ment any trends in the difference betweenthe active and passive approaches to anaer-obic tea production.

All measurements were continued untilthe 48-hour mark, at which point tea sam-ples were taken from barrels #1-4 and sentto BBC Labs for compost tea analysis. At

this point the physical experiment wascompleted.

Resultss There were minor differences in micro-

bial populations as indicated by bio-

plate counts between the sub-samplesof compost taken from the same batch

s There was no significant difference inO2 between passive and active treat-ments over the first 24-hour period.

s There was no significant difference inmicrobial populations as indicated by bio-plate counts between passive andactive treatments after the first 24hours, but there was a significant dif-ference after the first 48 hours in activsystems.

DiscussionOur experiments confirm those of othersthat so-called anaerobic tea systemsthosin which organic stock is simply soaked in waterare actually aerobic for the first 48hours or so of soaking. In other words,aerobic systems are merely extending thtime of useful extraction by putting moreoxygen into the system.

If suppressive microbes tend to be founmore in older teas (several days) thanyounger ones (1-2 days), it is possible thathe organic matter being extracted is,itself, undergoing decomposition in acomplex aerobic/anaerobic environment within the slurry, i.e., maybe the extratime needed to extract microbes is really just more time to give the feedstock timeenough to decompose to the appropriatemicrobial substrate.

Field test of the Cabrillo OrganicTea ApparatusThe COTA was field tested by farmers at

Route One Farms, Santa Cruz, CA. Theircritiques are as follows:

y The capacity of the machine was notlarge enough for field use. Given this limitation they adopted it for use on green-house seedlings. However, they modifiedthe bottom barrel by enlarging it to a con-tainer that can hold up to 250 gallons andare planning to use teas in the field at a50% dilution.

Defining Organic TeaExtraction SystemsOrganic tea systems have been describedas eitheranaerobic or aerobic dependingon the degree of aeration given to the sys-

tem. This is somewhat misleading. Thedistinction is the degree of aeration givento the system in order to allow it toextract over a protracted time period. Weprefer the terms passive (a contained orbagged slurry that is simply allowed tosoak in water) andactive or aerated (anorganic tea system that receives a boost of oxygen with the use of mechanical mix-ing, packed columns or forced air.)

Passive tea extraction systems are thosein which a feedstock is simply left to soak in water. After a few days, passive systems will become anaerobic and, as a result,begin to produce various organic acidssuch as butyric, proprionic and aceticplus the odors of reduced forms of nitro-gen (NH4) and sulfur (H2S) which inturn will attract flies. There is some evi-dence that the by-products of anaerobicdecay can actually harm plant roots(James Downer, pers. comm.).

The trouble with passive extractionmethods is that they can go anaerobicvery quickly. When you soak organicmaterials in water for more than a fewdays, aerobic microbes in the slurry pullall the oxygen out of the water. Thisturns over the production of the tea tooxygen-avoiding (anaerobic) microbes, which produce an inferior tea with feweravailable nutrients and organic acidsharmful to plant growth. Our researchindicates that there is usually enough dis-solved oxygen in clean water so thatanaerobic microbes aren't dominant forat least 24-48 hours under most condi-tions. After that, the quality of the tea

begins to deteriorate. All types of tea sys-tems should be aerobic. The major vari-able is the length of time that aerobicextraction is allowed to take place.

There is evidence that adding oxygento an organic tea slurry improves thequality of the extracted tea. This seemsto be because aeration extends the extrac-tion time, which allows the removal of beneficial organic compounds like vita-mins, enzymes, organic chelators plus abevy of beneficial microbes.RM & JM


11/32

11

W I N T E R 2 0 0 1 N U M B E R 9

y The top barrel is extremely heavy afterproducing tea due to saturated compost.Removing and replacing the compost takesmore than one person.

y The feedstock container was too difficultto use given its placement inside the topbarrel. They replaced it with a plastic con-tainer the goes all the way to the top of the barrel and although still heavy, easierto deal with.

y Screening and sprayhead clogging is aproblem with fine sized compost.

Suggestions for afield experiment protocolHaving reviewed over 100 papers onorganic teas, we are unable to reach a con-clusion as to the value or efficacy of organ-ic teas. The problem, as we see it, has beena lack of standard protocol for organic teaexperiments. A protocol is importantbecause of three major sources of varia-tion: 1) the organic feedstock, 2) themethod of extraction, and 3) the timeinterval of extraction.

The most difficult variable to control isthe feedstock, whether it is fresh manureor suppressive compost. A consistentsource of feedstock should be found andsub-samples taken fromthe same batch.If

possible, inorganic nutrient and bioassay tests should be done on pilot sub-samplesto establish the degree of variation withinthe feedstock.

The method of extraction is a functionof the type of extractor used, and the con-ditions under which the experiment takesplace. Replications should be assigned toextractors of similar design and aerationunits. Since multiple replications are so

important to a welldesigned experiment,it is important to find

a well functioning yetinexpensive extractordesign such as the onedescribed in thisreport. Experimentersshould also control forthe following environ-mental variables: 1)the temperature of extraction; 2) theamount of ambientlight; 3) the chemical

quality of the water used in extraction;and 4) the use of supplemental ingredi-ents.

The temperature of extraction & ambi-ent light. The organic tea apparatuses atCabrillo College were maintained outsideand under a shade structure. Tea produc-tion rates varied greatly with the swings indaily and seasonal temperatures. AtCabrillo College, ambient temperaturesvary from daytime highs in the upper 70s(August-November) to nighttime lows inthe lower 30s (December-February). Ourobservations indicate that below 45-50F extraction was noticeably slowed down.Most nutrients tend to be more soluble in warmer water, and because microbial respration rates are proportional to ambienttemperature, heating the slurry or keepingthe extractors in heated spaces might havesome merit in cool locations.

Chemical quality of the water. Thechemical properties of the water beingused can strongly affect the quality of teaproduced. Acid and alkaline water with little buffering capacity can keep certainmicrobes from flourishing. Excess salts cado the same thing. When possible, try touse filtered, spring or rain water, which will produce a richer tea.

Supplements to feedstock. Severalresearchers and practitioners have recom-mended the addition of concentrated supplemental nutrients to increase microbial activity in organic teas. These include sugars,unsulfured molasses (at a rate of 1 tbsp of molasses per 5 gals of water), rock fertilizerkelp and fish products and barley malt. We would only add the possibility of addingcommercial microbial cultures to jump-startmicrobial activity in organic teas.

The time of extraction. The time of tea

extraction strongly affects the quality andcomposition of organic teas. According to Amigo Cantisano53 Teas for nutrient andhumic acid extraction are ready in 1-2days...some disease suppression is notedfrom these young teas; more time isrequired for maximum disease suppressivteas.

An efficient organic tea experimentshould focus on a minimum number of variables at a time because of the inherentvariability of the testing situation.


12/32

12


Design and Construction Detailsof the Cabrillo Organic Tea ApparatusThe overall design of the Cabrillo Organic Tea Apparatus is simple, inexpensive (total cost:$303), and uses readily available parts. What follows are step by step instructions for buildinthe apparatus, completing assembly of six individual components, which make up the entire

extractor unit.These components are: The Containers The Packed Column The Pump Assembly The Spray Head The Feedstock Container Miscellaneous Parts

The order of assembly is important since completion of one component leads to the placemenand sizing of the next. [ All required materials and number of units needed (#) are shown i face, followed by an estimated cost ($); required tools are shown as underlined .]

The Containers (Fig. 6)(2) 55 gallon plastic barrels (cost: $100). Cut the tops off both barrels: Drill with bit a

hole on the top of each barrel on the inside of the lip. Insert the scroll saw and cut arounthe circumference of the barrel to remove the top.

Cut a hole in the bottom of the top barrel to-be: Draw a 10x 7 diamond shape using a pemanent marker. Using the scroll saw, follow your markings to remove the diamond.

(1) Automobile tire inner tube (cost $10). Use a utility knife to cut a piece of the inner tu(one layer thick) so that it extends 1 beyond the edges of the diamond. Measure and cut a sllengthwise in the middle of the piece of inner tube 3 long. Inside the barrel, sand the insidedges of the diamond as well as the edges of the inner tube with 80 grit sand paper. Apply waterproof silicone sealant to the sanded areas and glue the inner tube to the inside of the barel. This creates a funnel which prevents the tea from leaking out the sides of the bottom of tbarrel. It also reduces the splash and loss of tea as it falls between the barrels.

The Pump Assembly (Fig. 7)(1) hp submersible pump w/ auto float switch ($80). Check the size of your sub-

mersible pump line out. Make sure you have the right fitting to adjust the pipe size to .(1) 20 section of PVC pipe ($12). Cut a 18 piece of the PVC pipe. Glue the line

out fitting to the pipe and attach it to the pump. Place the assembled pieces inside the bottombarrel. Cut a 110 piece of the PVC pipe.

(8) 45 degree PVC elbows ($7). Wet/dry PVC cement. Glue a 45 degree PVC elboat each end of the 110 pipe. Make the 45 degree angles opposite each other, one facing dowto the pump and the other facing up towards the top barrel. Glue into place on the assembledpieces inside the barrel. Place(2) 2 lengths of 4x4 lumber ($5) spacers on the top of the botom barrel. Place the top barrel on the spacers.

Adjust the pump assembly so that the top of it extends out the back of the bottom barrel.

Measure the distance from the top of the pump assembly to the top of the top barrel and cut apiece of PVC pipe to size. Glue into pump assembly.(9) 1/2 90 degree PVC elbows ($7). Glue a 3 piece of PVC pipe into a 90 degree

elbow. Slip(1) ID (inside diameter) piece of clear poly hose ($1) over the PVC piecand secure with the second available hose clamp. This will connect to the spray head andserve as a visible flow check. Glue a 90-degree PVC elbow on the top end of the pumpassembly.

The Packed Column (Fig. 8)(1) 4 dia. PVC pipe, 26 long ($15). Place the PVC pipe inside the top barrel. Bring the

top of the pipe 2 from the top of the barrel and hold it there. On the outside of the barrel, with a tape measure, measure down 5 from the top of the barrel. Take the drill with the

Figs. 6-10 (this and the followingpage): Details of active compost teaapparatus.

Fig. 6 . Double-barrel active tea extractor showing outline of 55- gallon plastic barrels, pump assembly and wooden spacers between upper and lower barrels.

Fig. 7.Pump assembly, side view.

Fig. 8.Packed column filled with 4 inch PVC pieces, bolted inside of top barrel; a gravity-fed aeration system.


13/32

13

W I N T E R 2 0 0 1 N U M B E R 9

Benefits of organic teas: A review of the researchliterature

Teas Provide Inorganic Nutrients and Beneficial Organic Compounds The types and amount of nutrients in anorganic tea depend on the age and kind of material used. The nutrients from freshmanure teas tend to be soluble salts, espe-cially macronutrient (N, P, K, Ca, Mg andS) plus micronutrients (e.g., Fe, Zn, Mnand Cu).

Nutrients from more decomposed feed-stocks such as young or unstable composcontains some available nutrients not yetfixed in microbial biomass, but they alsoprovide organic nutrients like sugars andamino acids, plus organic chelating agents(humic and fulvic acids) that carry extract-ed micronutrients (e.g, iron, zinc, man-ganese and copper) to plants. Sincemicronutrients are the building blocks of plant enzymes, vitamins and hormones,organic teas can also increase a plants dis-ease resistance, vigor and hardiness by providing both micronutrients and the organ-ic chelating agents that make them avail-able. Organic teas also contain long-chaincarbon molecules which provide carbon

and oxygen for soil microbes, includingmycorrhiza. The mycorrhizal hyphae, inturn, greatly extend the root systems of plants, increasing their nutrient uptake,respiration, tolerance to weather extremesand possibly conferring some diseaseresistance.

Teas Suppress Certain Plant Diseases It has been shown that certain soilmicrobes have the capacity to suppressmany serious plant diseases1,2. The dis-ease-suppressive characteristics of organic

tea was reported as early as 1973 by Huntet al3.

Extractions fromwell-aged and suppres-sive composts have few soluble nutrients,but they do contain organic chelators andpopulations of various biofungicidalmicrobes. These teas have been shown toact as a natural fungicide, i.e., as an inocu-lum of microorganisms that can compete with and suppress some plant pathogens,especially foliar-fungal diseases.

and drill though the barrel and the pipe. Remove the pipe and measure down 2 from thefirst hole on the barrel. Drill a second hole though the barrel. Measure 2 down fromthe first hole on the pipe and drill a second hole.

Take a 5x 5 piece of chicken wire and cover the bottom end of the 4 pipe. Fold thechicken wire around the outside of the pipe and slide(1) 4 threaded hose clamp ($3)over the wire. Secure the wire to the pipe by threading down the clamp. This serves to

keep the 1 PVC pieces inside the packed column.(1) 10 length of 1 PVC pipe ($6)cut into 1 sections with PVC pipe cutters or hack saw. Attach the Packed Column to theinside of the barrel using(2) x 2 carriage bolts, (4) washers and (2)

wingnuts . Fill the column with the PVC pieces to within 1 of the top.

The Spray Head (Fig. 9)(3) PVC tee s ($3), (3) PVC slip-fit ball valves ($18), (1) PVC cross ($2),

(4) PVC end caps ($1). Individually assemble the top, connector, and bottom piecesof the spray head and then glue the three pieces together. The connector piece should belined up directly underneath the line above it, so that it is running back towards the cross-piece. Attach the bottom piece to the connector piece so that the spray lines parallel theconnector piece. Check the spray head assembly for fit in the top barrel.(2) hoseclamps ($3). Connect the spray head to the pump assembly and secure using a hose

clamp. Stabilize the spray head by placing a yardstick across the top of the barrel andunder the top piece of the spray head.

The Feedstock Container (Fig. 10)Cut a 4 diameter circle from(1) 4 x 4 piece of shade cloth ($4). Assemble feedstock

container ring. Refer to diagram for feedstock container ring assembly, using the 1/2PVC straight piece sections and 45- and 90-degree PVC elbows. Place shade cloth insidering so that there is a 1 to 2 margin around the outside.

Use zip-ties (1 package $7) every 1 to fasten the shade cloth around the ring. Use(2) 10 S-hooks ($2) (bought or easily made from 14-gauge wire) to hang inside the topbarrel. Note: the inverted side of the ring should fit around the packed column.

Miscellaneous PartsThe Barrel Spacers. On the two 2 lengths of 4x4 lumber, measure in from each side 9.

(8) 2 C-clamps ($3). Center two C-clamps at the 9 marks and nail into place. Leave a1 gap between the C-clamps. These will serve to hold two screens in place.(2) window screen kits ($12).

The Barrel Spacer Screens. Assemble two 12xl2 screens using a window screen kit orfrom existing materials. These serve to screen compost particles from the tea and keepcompost from settling in the bottom barrel. With two screens, one can be cleaned easily.

Continued on next pag

Fig. 9.Spray head assembly, showing top (above barrel), bottom (inside bar-

rel) and connecting (middle) sections.

Fig. 10.Feedstock container, with PVC ring made from elbow and straight pieces, and porous bag assembly from shadecloth.


14/32

14


References A key feature of this project report is an exten-sive bibliography of the research conducted oncompost teas. A majority of these references are provided here; the full bibliography provided with this report (88 references, total) may be obtained by contacting OFRF or by visiting our website: www.ofrf.org.

4 Weltzien HC. The effects of compost extracts onplant health. In: Global Perspective on Soil

Agricultural Systems; 1986;2:551-553.

5 Weltzien HC. The Effects of Composted OrganicMaterials on Plant Health. In: Agriculture,Ecosystems and Enviromment; 1989 27:439-446.

6 Spring DE (et al). Suppression of the apple collarrot pathogen in composted hardwoood bark.Phytopath. 1980; 70: 1209- 1212.

1 Adams PB. The potential of mycoparasites for bio-logical control of plant diseases. Ann. Rev. of Phytopath. 1990 28:59-77.

2 Cook RJ, Baker KF. The Nature and Practice of Biological Control of Plant Pathogens. St. Paul,MN: Amer. Phytopath. Soc. 1983.

3 Hunt P, Smart C, Eno C. Sting Nematode,Belonolaimus logicaudatus,immobility induced by extracts of composted municipal refuse. Jour.Nematol.,1973;5:6063.

At the University of Bonn, Germany,Heinrich Weltzien pioneered research inwater extracts of compost. He showed4that organic tea can be used as a foliar spray to inhibit Phytophthoraon tomatoes andpotatoes. Weltzien also showed that the sup-pressive effect of organic teas are of a livingmicrobial nature. Sterilized or micron fil-tered tea had little ability to impactpathogens5. He also documented that plantstreated with tea appeared healthier and morevigorous than other plants.

Using organic teas or special compostextracts, other researchers and growers havereported modest to major control of severalplant diseases with organic teas including: Apple Collar Rot6, Apple Scab7, Botrytis orGrey Mold8,9, Downy Mildew10,Fusarium11, Phytophthora12,13, PotatoBlight14, Powdery Mildew orErysiphe 15,Pythium14,16,17,18,19 and Rhizoctonia19,20. According to these authors, compost teascoat plant surfaces (foliar application) orroots (liquid drench application) with livingmicroorganisms and provide food for benefi-cial microbes. This helps secure a diverseand healthy food web community wheresymbiotic bacteria and fungi help providedisease resistance.

In addition, several types of organic feed-

stocks have produced favorable suppressiveresults including composts5,11,21,22,23,24,25,26,27, municipal and agricultural wastes28and various types of lignous materials suchas wood wastes and peat moss6,12,17,18,20,29,30,31,32,33,34,35,36,37,38.

The principle suppressive microbes incompost teas can suppress diseases in several ways39: They induce resistance against pathogens(pre and post-infection). They produce chemical inhibitors asreported for the suppression of Phytophthora

root rot in media amended with hardwoodbark 12,31. They inhibit pathogen spore germination.

They antagonize and compete withpathogens through the antibiotic effects of parasitism, hyperparastism and nutrientcompetition. Some microbes, especially bac-teria, produce antibiotics which cover thesurface of the crop and thus prevent infec-

tion by the pathogen. They extend the root system of plants,and thereby improve nutrient uptake, plusincreased food storage and soil respiration.

There is also growing evidence that chemi-cals called siderophores, pseudobactins andpseudomycins produced by the bacteriaPseudomonas spp. exert a powerful suppres-sive effect on other organisms40. Kai et al.33found that ten proteins from secondary metabolites of plant or microbial origineffectively suppressed certain pathogenicfungi. In some cases, cyanids and antibioticsinteract with the host plant and create resist-ance to disease.

Its not always clear which of these effectsis most important to a general impression of disease-suppression as noted in the litera-ture. Furthermore, not all such experimentshave been favorable. Using aerated Luebkecompost tea, made in a lab extractor with avortex nozzle for aeration, Wittig41 reportedthat aerobic compost tea was not effective incontrolling apple or pear scab, downy mildews, brown fruit rot or peach leaf curl.He generally rejected them as effective con-trols for foliar diseases of fruit trees andgrapes. Wittig goes on to note:Considering that the microorganisms pres-ent in compost may be better adapted to asoil environment, perhaps there is greaterpotential for its use as a drench in control-ling soil-borne pathogens.

In spite of the mixed results, there seemslittle doubt that certain beneficial microbescan be water-extracted from aerated organicslurries and applied to leaf surfaces (via foliarfeeding) and/ or root systems (via drenching

or fertigation). These beneficial microbesinclude mycoparasites42, rhizospherecolonies43, hyperparasitic fungi40,44,45,46,

epiphytic microbes47,48 as well as specificbacteria such asPseudomonas 49, Azotobacter 50, and certain fungi likeTrichoderma and Gliocladium51,52. Apparently disease suppressive microbes thahave been extracted from the compost areable to colonize the surface and roots of plants when applied properly. Organic teassimply concentrate these beneficial microbesand allow the grower to apply them in aconvenient, concentrated form for nutrients,resistance and disease control53. In a realsense, organic teas are a concentrated liquidfertilizer and inoculum of beneficialmicrobes.

It is worth noting that between 50 and 80percent of a plants photosynthates (sugars,complex carbohydrates, amino acids andproteins) are translocated below ground intothe root system of most plants (ElaineIngham, pers. comm.). Of this amount,40 to 60 percent are released by roots as exudates that supply food and create the condi-tions for colonization of soil microorganismsliving in the rhizosphere (the microscopichabitat surrounding roots). These organ-isms, in turn, excrete, die, decay and areconsumed by other organisms in the soilsfood chain. Through this process of growth,death and decay, the waste and by-productsof soil microbes become macro and micro-

nutrients for plants. From these facts, onemight hypothesize a profound reciprocal(symbiotic) relationship between plants andmicrobes as yet unexplained.

Teas Help Build Soil Structure The microorganisms found in organic teasexcrete organic gums and resins that, togeth-er with fungal hyphae, bind soil particlesinto structural aggregates, improving bothsoil structure and water-holding capacity.Thus, when organic teas are applied as a soildrench, they can promote good soil struc-ture.RM & JM

Continued from previous page


15/32

15

W I N T E R 2 0 0 1 N U M B E R 9

7 Andrews, JH, Harris RF. Compost extracts and thebiological control of apple scab. Can. J. Plant Path.1992;14:240 (Abstr.).

8 Elad Y, Shtienberg D. Effects of compost waterextracts on grey mould,Botrytis cinerea.CropProtection 1994;13 (2):109-114.

9 Stindt A, Weltzien HC. Der Einfluss von wassrigen,mikrobiologisch aktiven Extrakten von kom-postiertem organischen Material auf Botrytis cinerea.Rijisuniversiteit Gent 1988;53: 379-388.Mededelingen Faculteit Landbouwwetenschappen.

10 Weltzien HC, Ketterer N. Control of Downy Mildew, Plasmopara niticola(de Bary) Berlese et deToni, on grapevine leaves through water extractsfrom composted organic wastes. Phytopath.1986;76:1104.

11 Khalifa O. Biological control of Fusarium wilt of peas by organic soil amendments. Ann. Appl. Biol.1965;56:129-137.

12 Hoitink HA, van Doren DM, Schmitthenner AF.Suppression of Phytophthora cinnamomi in a com-posted hardwood bark potting medium. Phytopath.1977;67:561-565.

13 Ketterer N, Weltzien HC. Wirkung von Kompost-und Mikroorganismen Extraklenauf den Befall terKartoffeldurchPhytophthera infestans.Mitt. Biol.Bundesanst. 1988;245-346.

14 BioCycle Staff. Applying compost tea to preventpotato blight. BioCycle 1997 May; 53.

15 Budde K, Weltzien HC. Untersuchungen zur Wirkung von Kompostextrakten undKompostsubstraten im Pathosystem Getreidt-EchterMehitau (Erysiphe graminis).Mitteilungen derBiologischer Bundesanst 1988;245:366.

16 Boehm MJ, Madden LV, Hoitink HA. Effect of organic matter decomposition level on bacterialspecies diversity and composition in relationship toPythiumdamping-off severity. Appl. Environ.Microbiol. 1993;59:4171-4179.

17 ChenW, Hoitink HA, Madden LV. Microbial activi-ty and biomass in container media predicting sup-pressivness to damping-off caused by Pythium ulti-mum.Phytopath. 1988;78:1447-1450.

18 Hadar Y, Mandelbaum R. Suppression of Pythiumaphanidermatumdamping-off in container mediacontaining composted liquorice roots. Crop Protect.1986;5:88-92.

19 Hoitink HA, Kuter GA. Effects of compost ingrowth media on soilborne plant pathogens. In: TheRole of Organic Matter in Modern Agriculture. Y.Chen & Y. Avnimelech (eds), Martinus Nyhoff Publ., Dordrecht and The Netherlands. 1985. pgs.289-306.

20 Chung YR, Hoitink HA. Interactions between ther-mophilic fungi and Trichoderma hamatumin sup-pression of Rhizoctoniadamping-off in a bark com-post-amended container medium. Phytopath.1990;80: 73-77.

21 Hadar Y, Mandelbaum R, Gorodecki B. Biologicalcontrol of soilborne plant pathogens by supressivecomposts. In: Biological Control of Plant Diseases:Progress and Challenges for the Future. E.C.Tjamos, G.C. Papavizas and R.J, Cook (ed.),NATO ASI Series No. 230. Plenum Press, New

York, NY. 1992. pgs 79-83.

22 Hoitink HA, Fahy PC. Basis for the control of soil-borne plant pathogens with composts. Annual Rev.Phytopath. 1986;24:93-114.

23 Lopez-Real J, Foster M. Plant pathogen survivalduring the composting of agricultural organic

wastes. In: Composting of Agricultural Wastes. J.K.R. Glasser (eds), Elsevier Applied SciencePublishers, New York, NY. 1985.

24 Lumsden RD, Lewis JA , Miller PD. Effect of composted sewage sludge on several soilbornepathogens and diseases. Phytopath. 1983;73:1543-1548.

25 Van Assche C, Uytterbroeck P. The influence of domestic waste compost on plant diseases. ActaHorticultura 1981;126:169-178.

26 Weltzein HC, et al. Improved plant healththrough application of composted organic materialand compost extracts. pgs 377-379. In:

Agricultural Alternatives and Nutritional Self-Sufficiency. A. Djigma et al. (eds), Proceedings of the IFOAM Seventh International ScientificConference, Ouagadougou, Burkina Faso. 1989.

27 Weltzein HC. Some effects of composted organicmaterials on plant health. Agriculture, Ecosystemsand Environment 1989;27:439-446.

28 Tranker A. Use of agricultural and municipalorganic wastes to develop suppressiveness to plantpathogens. Pgs 35-42. In: Biological Control of Plant Diseases. E.C. Tjamos, G.C. Papavizas andR. J. Cook (eds). NATO ASI Series No. 230.Plenum Press, New York, N.Y. 1992.

29 BioCycle Staff. Tree bark compost for plant pro-tection. Pgs. 158-160. In: The Biocycle Guide toThe Art & Science of Composting. BioCycle:

Journal of Waste Recycling. JG Press, Inc.,Emmaus, PA. 1991.

30 Hoitink HA, Composted bark: a lightweightgrowth medium with fungicidal properties. PlantDisease 1980;64: 142-147.

31 Hoitink HA, Fungicidal properties of compostedbark. Compost Science/Land Utilization 1980Nov-Dec.;24-27.

32 Hoitink HA, Inbar Y, Boehm MJ. Status of com-post-amended potting mixes naturally suppressiveto soilborne diseases of floricultural crops. PlantDisease 1991 Sept; 869-873.

33 Kai H, Ueda T, Sakaguchi M. Antimicrobial Activity of Bark-Compost Extracts. Soil Biol.Biochem. 1990;22 (7): 983-986.

34 Kuter GA, (et al). Fungal populations in containermedia amended with composted hardwood bark suppressive and conducive toRhizoctoniadampingoff. Phytopath., 1983;73:1450-1456.

35 Nelson E B, Hoitink HA. The role of microor-ganisms in the suppression of Rhizoctonia solani incontainer media amended with composted hard-

wood bark. Phytopath. 1983; 73:274-278.

36 Nelson EB, Kuter GA, Hoitink HA. Effects of fungal antagonists and compost age on suppres-sion of Rhizoctoniadamping-off in containermedia amended with composted hardwood bark.Phytopath. 1983;73:1457-1462.

37 Papavizas GC, Davey CB.Rhizoctoniadisease of bean as affected by decomposing green plantmaterials and associated microfloras. Phytopath.1960;50:516-521.

38 Tahvonen R. The suppressiveness of Finnish lightcoloured sphagnum peat. J. Sci. Agric. Soc. Finl.1982;54: 345-356.

39 Brinton WF. The Control of Plant PathogenicFungi by Use of Compost Teas. Biodynamics,

January/February 1995: 12-15.

40 Kloepper J, et al.Pseudomonas siderophores: A mechanism explaining Disease-Supressive soils.Current Microbiology 1980;4:317-320.

41 Wittig H. Final report: Fruit and ornamental dis-ease management testing program related to theuse of organic foliar amendments. OrganicFarming Research Foundation, Santa Cruz, CA.1996.

42 Boehm M J, Hoitink HA. Sustenance of microbiaactivity and severity of Pythiumroot rot of Poinsettia. Phytopath. 1992;82: 259-264.

43 Chao WI (et al). Colonization of the rhizosphereby biological control agents applied to seeds.Phytopath. 1986;76:60-65.

44 Hijwegen T, Buchenauer H. Isolation and identifcation of hyperparasitic fungi associated withErysiphaceae.Netherlands Jour. Plant Path.1984;90:79-83.

45 Scher F M, Baker R. Effect of Pseudomonas putiand a synthetic iron chelator on induction of soilsuppressiveness toFusarium wilt pathogens.Phytopath. 1982;72:1567-I573.

46 Schonbeck F. Dehne HW. Use of microbialmetabolites inducing resistance against plantpathogens. Pgs 361-375. In: Microbiology of thePhyllosphere. N.J. Fokkema and J. van denHeuvel (eds), Cambridge Univ. Press, CambridgeMA. 1986.

47 Redmond RD, Marois JJ, MacDonald JD.Biological control of Botrytis cinereaon roses withepiphytic microorganisms. Plant Disease 1987;71799-802.

48 Wood R. The control of diseases on lettuce by theuse of antagonistic organisms. 1. The control of Botrytis cinereaPers. Ann. Appl. Biol. 1951;38:203-216.

49 Jager G, Velvis H. Biological control of Rhizoctonia solani on potatoes by antagonists. 4.Inoculation of seed tubers withVerticillium bigutatumand other antagonists in field experiments.Neth. J. Plant Pathol. 1985;91:49-63.

50 Meshram SW. Suppressive effect of Azobacter chroaccumon Rhizoctonia solani infestation of potatoes. Neth. J. Plant Pathol. 1984;90:127- 132

51Hubbard JP, Hannan GE, Hadar Y. Effect of soil-borne Pseudomonas spp. on the biological controlagent, Trichoderma hamatum,on pea seeds.Phytopath. 1983;73:655-659.

52Papavizas GC.Trichoderma and Gliocladium:Biology, ecology and potential for biocontrol. AnRev. Phytopath. 1985;23:23-54.

53Cantisano AB. Compost TeasHow to Make andUse. P.O. Box 1622, Colfax, CA 95713. 1994.

This complete project report (Project #40) is 47 pages, plus eight appendices. Tmain report and bibliography are availa from OFRF by mail or by visiting our wsite (www.ofrf.org); project appendices mbe obtained by mail only and will be seupon request.


16/32

16


Therefore, a study was undertaken to look

at the effectiveness of disease control withcompost extracts on some cash crops inthe Southern Interior of British Columbia.

Project Objectivess To determine which compost extract is

more effective in reducing disease instrawberries, lettuce, broccoli and leeks;

s To identify the point at which applica-tion of the compost extracts are moreeffective.

Experimental MethodsGeneral description of study siteThe trials took place at Wildflight Farmlocated in the floodplain of the ShuswapRiver near Mara in the North Okanaganregion of British Columbia. The annualrainfall of the area is approximately 1,300mm [51 in] with warm, humid summers.The plots were established on level orslightly undulating land with a soil of aclay loam texture. This particular farmprovides produce for the fresh market anda CSA, and thus grows a wide variety of

vegetables including brassicas, tomatoes,potatoes, salad greens, onions, garlic, leeks,strawberries, cucurbits, carrots and beets.

Crop planting and other detailsStrawberries were established three yearsprior at recommended densities. Plots weresuperimposed onto the existing strawberry fields and were ribboned off. Regular culti-vations were done to control weeds. Nofertilizer or sprays were applied throughoutthe strawberry season. Similarly, compostextract treatments were superimposed ontoexisting leek fields. Here the spacing wassix inches between plants and about threefeet between rows. Leeks were cultivatedfor weeds several times prior to harvest.Lettuce (Paris cos variety) and broccoli(Pakman variety) were seeded into trays with the following soilless mix: 4:4:1 of chicken manure compost, peat and ver-miculite, respectively. Some dolomitic lime was also added to adjust the pH to 7.Lettuce and broccoli seedlings were raisedin the greenhouse until ready for trans-

planting. During this time, overhead watering was used and no extra fertilizer was added. Lettuce was planted out at 1 fx 1 ft spacing while broccoli was plantedat 1.5 ft x 3 ft spacing.

Compost extract preparationCattle compost from Greenleaf (Olds, Alberta) and chicken manure compostfrom a poultry farm in Armstrong, BritishColumbia, were used for the extractions.Both composts were actively turned forthe first month and then only once amonth for the next three months, thencured for another six months. A methodof compost tea extraction proposed by researchers at the Woods Hole Laboratory was used8. This resulted in an 8:1 water-to-compost dilution. Water was added tothe respective composts (cattle and chick-en) and t

Benefits of Compost Tea

Documents