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Tuesday, Jan. 26, 2010

The Future of Farming

Sweet Water Organics advances aquaponics in Milwaukee

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With the heavy residue of industry still tattooed on its landscape, Milwaukee might not seem like a window into the future of American farming. But it is.

Demand for food is growing with the swelling world population, while natural fish populations diminish and farmland disappears under the tread of development, making it necessary to adjust the way we grow our food. Milwaukee is the headquarters for several visionaries in today’s urban agricultural movement who are using a system of cultivation called aquaponics to raise fish and grow vegetables.

Step over the threshold of Sweet Water Organics in Bay View, and a massive manufacturing plant that once produced heavy machinery for Harnischfeger Industries reveals its new purpose as an experimental commercial urban fish and vegetable farm.

“If the Sweet Water experiment can prove commercially viable,” says James Godsil, who co-owns the business with Josh Fraundorf and Steve Lindner, “that would be cause for great hope for our Great Lakes Heartland cities of 10,000 under-used or unused vintage factory buildings.”

Aquaponics is an efficient, compact food production method that combines fish farming (aquaculture) with hydroponics, the cultivation of plants without soil, in one integrated system. In many ways, it mimics Earth’s natural ecosystems. Fish digest food and excrete waste in the water they’re living in. A beneficial form of bacteria converts the fish waste to nutrients used by plants growing in the same water. When they consume these nutrients, the plants purify the water, keeping the water healthy enough for the fish to live in. In this mini-ecosystem, both fish and plants thrive.

What makes aquaponics perfect for the empty industrial buildings littering America’s old manufacturing cities is that soil isn’t required. Aquaponics systems can be set up virtually anywhere fresh food is needed. In most climates, a greenhouse (or basement, garage or abandoned warehouse) is necessary to protect the delicate system from environmental factors like fluctuating temperatures, wind, snow, rain and insects. Since the dawn of agriculture, farmers have been at the mercy of the elements. Now the technology to control the environment within which their crops are being grown is a reality.

When Godsil, Fraundorf and Lindner began construction on their aquaponics system last February, they modeled it after MacArthur genius-grant-winner Will Allen’s pioneering three-tiered, biointensive fish-vegetable garden at Growing Power on Silver Spring Drive. The owners applied their skills—Lindner is a home builder and property owner (including the building Sweet Water Organics leases), and Godsil and Fraundorf run a roofing company—to the demolition and renovation needed to transform the 11,000 square feet of space into a suitable urban farm. They repaired the roof and replaced the grimy clerestory glass near the 50-foot ceiling with clear polycarbonate insulating windows. They cut 4 feet below the concrete floor to construct four parallel channels that will each hold an 11,000-gallon water raceway for the fish. Above the raceways, they built an impressive lumber structure to hold the plant beds.

When Sweet Water Organics was ready for fish, they looked to Fred Binkowski, a senior scientist at Great Lakes WATER Institute, a University of Wisconsin System research facility on the Milwaukee harbor. He coordinates outreach programs through WATER’s Aquaculture and Fisheries Research Center and the UW Sea Grant Advisory Services Program, and offered his research results from raising yellow perch in a commercially scaled recirculating aquaculture system (RAS). On July 8, 1,200 small yellow perch left the institute for their new home at Sweet Water. On July 22, another 1,200 perch were added, as well as 33,000 tilapia fingerlings from AmeriCulture Inc. in New Mexico.

As Jesse Hull, Sweet Water Organics’ lead horticulturist, explains it, water from each raceway is pumped up to two stacks of gravel. The water flows across the gravel, where bacteria breaks down the toxic ammonia from fish waste and converts it to nitrite and then to nitrogen, a key nutrient for plant development. In the middle bed, watercress is grown as a secondary means of water filtration. In the top bed, the water fertilizes hundreds of green plants, such as basil and lettuce, thriving beneath water-cooled grow lights. Finally, the filtered water flows from the growing beds back into the fish tanks. The “outside” inputs include oxygen from an aeration system, commercial fish food and swimming pool heaters that warm the water to 70 degrees for the perch and 85 degrees for the tilapia.

The nutrient-rich water of the fish tanks can support dense plant spacing, allowing urban growers like Sweet Water Organics to produce a substantial plant yield using a fraction of the water, machinery and labor required to cultivate crops on an open field. Because herbicides and pesticides aren’t needed in the controlled setting of an aquaponics system, consumers can enjoy their fish and vegetables knowing they haven’t been exposed to harmful chemicals.

Godsil says Sweet Water Organics will derive income from the sale of its fish, greens, cereal grains such as wheat grass, worms, worm castings and compost. They also hope to expand to include tours, training programs and installation of aquaculture systems. The owners plan to expand their operation in the coming months by adding three more fish tanks. Dec. 23 saw Sweet Water Organics’ first fish auction, and the lucky buyers will be picking up their newly purchased perch in February, when the fish are big enough to harvest.

Because Milwaukee is the headquarters for several visionaries in today’s urban agricultural movement, we, the residents, get to reap the rewards. Local urban agriculture, specifically aquaponics, reduces the use of fossil fuels for food production and transport; provides jobs for a ready workforce; produces fresh foods for underserved populations; and finds new uses for old buildings—preserving the memory of the heavy industry that Milwaukee was built on, and starting a new legacy on which to build its future.

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