BIOCYCLE FEBRUARY 2009 27

ACROSS the U.S., as small, localgroceries close in the face ofcompetition from large, distantsupercenters, more and moreimpoverished inner city and ru-ral residents live in “fooddeserts,” without access to

fresh, affordable food. In 2007, USDA re-ported that 7 percent of U.S. households suf-fer from low food security while 4.1 percentof U.S. households suffer from very low foodsecurity. A project at Saginaw Valley StateUniversity (SVSU) in Saginaw, Michigan,set out to meet these challenges throughaquaponics (a combination of hydroponicsand aquaculture) and vermicomposting.

In 2003, a pair of experimental green-houses was developed at SVSU by a multi-disciplinary team of faculty, staff and stu-dents. Funded by a grant from the AllenFoundation, a Midland, Michigan-basedgroup, the project seeks to identify a cost-ef-fective, year-round means to produce fruitsand vegetables locally and organically. TheSVSU system incorporates three basic fea-tures: An economically designed aquaponicssystem to efficiently grow fruits and vegeta-bles with minimal horizontal space, fertiliz-er and water; Vermiculture to efficientlyconvert campus food waste and paper wasteinto organic fertilizer for use in the system;

and, Renewable energy, such as passive so-lar heat, to cut the costs of operating boththe vermiculture and hydroponic units.

Four criteria drove the project: Cost ofcomponents and operations must not ex-ceed what the global market can currentlybear; Scale of the project must be local, withdimensions such that losses do not exceedgains; Resource availability, with local con-struction materials and alternative energysources used whenever possible; and Easeof Implementation, with installation andoperation managed by the local labor force.

The aim was to develop a system thatcould be widely replicated in economicallyblighted regions, used as a cost-effective ve-hicle to teach the public the importance ofgrowing the right fruits and vegetables toensure a healthy diet. The grand vision wasto ultimately establish regional productionsystems in population centers worldwide.

STARTING WITH HYDROPONICSHydroponics is gaining widespread at-

tention because it can outperform soil-based cropping, due to more efficient up-take of nutrients, with faster plant growthand higher yields per square foot of hori-zontal area. In the first production year atSVSU, three hundred pounds of tomatoeswere produced on a tiered hydroponic unit.

Project atSaginaw ValleyState Universityin Michiganexperiments withaquaponics andvermicompostingto increase foodsecurity.

Beth Jorgensen, EdwardMeisel, Chris Schilling,

David Swenson andBrian Thomas

FISH AND WORMS

DEVELOPINGFOOD PRODUCTIONSYSTEMS INPOPULATION CENTERS

Greenhouses integratehydroponics andvermiculture for year-round fruit and vegetableproduction, such as tomatoplants (left).

The high cost for turnkey hy-droponic systems can be pro-hibitive, so the SVSU teamused a relatively primitive, do-it-yourself system, with cheapand readily available materialsfrom the local hardware store:two-by-four lumber, plastic wa-ter pipe and an ordinary foun-tain pump. A provisionalpatent application has beenfiled on this system.

Other cost-intensive aspects of hydropon-ics are electricity to operate pumps and ar-tificial lighting, and heat for year-roundgrowing. Although alternative energysources like wind turbines, solar panels,geothermal heat pumps and biomass fur-naces have high capital costs, once opera-tional these investments provide cheap,clean energy.

One low-cost energy solution used atSVSU is passive solar heating of the bench-es that support potted plants. Benches wereconstructed from recycled pickle barrelsfilled with water and topped with durable,recycled fencing material. The water bar-rels provide a significant thermal bufferingcapacity that allows solar heat, absorbedduring the day, to be released at night.

INTRODUCING FISH AND WORMSSpecialty chemicals that serve as plant

nutrients and herbicides pose anothercostly problem with hydroponics, as theyare usually produced from nonsustainablepetroleum or natural gas. At SVSU, a com-bination of vermicompost tea and the de-velopment of aquaponics have replacedthese chemicals.

Aquaponics is essentially the same as hy-droponics, except that plant nutrients areprovided by fish excrement instead of syn-thetic chemicals. Also, plants filter the wa-ter before it returns to the fish tanks. Usingsimple plumbing and hardware, water in afish tank is circulated through a hydropon-ic system where naturally occurring bacte-ria produce powerful organic fertilizer. Theonly chemical input is fish food.

At SVSU, a 150-gallon water tank con-tains 12 Koi fish. A fountain aerates the wa-ter for the Koi, and a pump circulates fishtank water into two 50-gallon plastic tanksthat serve as hydroponic grow beds. Thewater in each grow bed recirculates backinto the fish tank using a so-called “ebb andflow” system, where an electric timer con-trols a pump that intermittently floods anddrains each grow bed. The grow beds arefilled with Hydroton clay aggregate, a grav-el-like material that is manufactured inhigh-tech kilns in Germany, and supportsthe roots of the growing plants. By simplycirculating fish tank water through eachgrow bed, two types of bacteria, Nitro-somonas and Nitrobacter, naturally beginto grow on aggregate surfaces. In turn,these bacteria convert ammonia, which isexcreted by the fish and dissolved in water,

to nitrate, a powerful organic fertilizer(similar to the fertilizer used in large-scaleAmerican agriculture, conventionally pro-duced from natural gas).

SVSU is now incorporating a vermiculturesystem into the university greenhouses. Af-ter attending a short course from Will Allenat Growing Power, Inc. (see “CompostingAnd Local Food Merge At Urban Garden,”Biocycle November 2008), the followingwaste recycling process was implemented,with cooperation from Aramark Corpora-tion, the manager of SVSU Dining Services.

Cooks in the university kitchen placefruit and vegetable scraps into five-gallonplastic buckets. A Starbucks café located oncampus provides spent coffee grounds. Onany given school day, 10 to 15 buckets ofcombined food scraps and coffee groundsare hauled to the university greenhouses.The weight and contents of each bucket arerecorded to monitor consumption rate. Dur-ing the fall 2008 semester, 15,175 pounds ofcombined food scraps and coffee groundswere collected.

At the greenhouse, red wiggler wormsare cultivated in a series of eight vermicul-ture beds, 4 feet wide by 8 feet long by 8inches high, built from ordinary construc-tion lumber. Worms are fed a mixture of 50percent food scraps, including coffeegrounds, and 50 percent shredded officephotocopier paper donated by Veteran’s Af-fairs Medical Center of Saginaw, Michigan.

Vermicompost is slowly generated andperiodically separated from the worm binusing a simple sieve consisting of a galva-nized wire screen (1/4 to 3/8-inch squaremesh). The screen is laid on top of a wormbin, and raw material (worms plus com-post) is gently spread onto the screen’s sur-face. Fleeing from the overhead light, theworms quickly migrate through the screen,falling below into the bed.

Each bed is monitored by an inexpensivehandheld probe that simultaneously mea-sures soil moisture and pH. Moisture con-centration must be maintained between 50and 60 percent, while pH must be main-

28 BIOCYCLE FEBRUARY 2009

Leachate is collected from thevermicompost bins, andaerated to produce composttea.

The school’s aquaponics systemhas a 150-gallon tank with 12Koi fish.

tained between 6 and 8. By carefully controlling what theworms eat, pH can be maintained without addition of chem-icals. To aerate the mixture, the solid material in each wormbed is occasionally turned by pitchfork, as needed.

To maintain the correct moisture concentration, watermist is briefly sprayed on the surface of each worm bed dai-ly, using a garden sprayer controlled by an electronictimer. Excess water leaches through the vermicompost anddrains through a series of 1/2-inch diameter holes drilledinto the plywood bottom of each worm bed. The aqueousleachate drips into a series of gutters fabricated from re-cycled plastic drain pipe, and is collected in a series of 5-gallon plastic buckets.

Leachate collected in each bucket is periodically pouredinto 55-gallon recycled plastic barrels. These barrels are aer-ated with a simple fish tank aerator, which reduces odor andalso keeps bacteria active, turning the leachate into a valu-able vermicompost tea. The tea is then used in the universi-ty greenhouse to fertilize plants grown hydroponically or intopsoil, providing an economic alternative to commercial nu-trient solutions. The solid compost that remains is used as asoil amendment in potted plants in the greenhouse.

COMMUNITY OUTREACHIn 2007, the Green Cardinal Initiative (GCI) was formed,

a consortium of students, faculty and staff interested indefining SVSU’s role in the green movement, both withinand outside the university. Initiated by sociologist BrianThomas, GCI originated around activities in the greenhouseincluding developing methods for local food production anddistribution in urban settings, engaging student artists inpublicizing GCI and food production activities, and develop-ing affordable energy and fertilizer options for both urbanand rural settings in the U.S.

The Greenhouse Project and GCI have coordinated withthree local nonprofits located in an economically depressedpart of Saginaw — Houghton Jones Neighborhood Center,

the Good Neighbors Mission and the Mustard Seed — to de-velop the Saginaw Urban Food Initiative. The aim is to in-crease the availability of fresh produce to the communitythrough the development of urban agriculture. Funding wasobtained from the Saginaw Community Foundation to installhydroponics units in the Houghton-Jones NeighborhoodCenter and the Good Neighbors Mission to explore the po-tential of year-round food production. The project’s goal is totake systems that have been tested at SVSU and examinetheir effectiveness in real-world circumstances.

With technical support and training by SVSU faculty andstaff, members of these two organizations recently began op-erating hydroponics systems, monitoring productivity and la-bor and energy requirements. Similar to the setup at SVSU,vermiculture systems have been established at each site tosupplement the hydroponics systems. Staff members at eachsite bring food waste and scrap paper from home to feed theworms.

Using experimental data from the university greenhous-es, a financial model is currently being built to calculate theanticipated benefits that these community centers and oth-er prospective organizations can anticipate. Input data in-cludes labor requirements, installation and operating costs,rates of worm reproduction and the rates of food waste andpaper waste delivered. Output data includes rates of wastereduction and the yields of produce, worm tea and vermi-compost.

Additional information on this and other projects un-derway at the SVSU greenhouses can be found atwww.greencardinal.org. �

Beth Jorgensen, Ph.D., is an Assistant Professor of English; Ed-ward Meisel is a Chemistry Lecturer and University GreenhouseDirector; Chris Schilling, Ph.D., is the C.J. Strosacker Professorand Chair of Engineering; David Swenson, Ph.D. is the Dow Pro-fessor and Chair of Chemistry (retired); and Brian Thomas,Ph.D., is an Assistant Professor of Sociology.

BIOCYCLE FEBRUARY 2009 29

ADVANCING COMPOSTING, ORGANICS RECYCLING& RENEWABLE ENERGY

419 State Avenue, Emmaus, PA 18049-3097610-967-4135 • www.biocycle.net

Reprinted With Permission From:February, 2009