Let’s be honest, the current commercial system for producing, packing, and shipping foods is not sustainable. On average, our food travels more than 1,500 miles before it reaches our plates. It is not a wonder that lettuce in the store sometimes looks exhausted; I would be too after such a trip! Shipping American apples to South Africa to be waxed and then shipping them back again makes little sense, as does the odd fact that it is difficult to buy a good potato in Idaho because avid exporting to other states takes the crop away from the locals.
However, neither do northerners have to succumb to a diet of dried venison and wild rice to make it through the winter (though both are very tasty!), with a steady dose of squashes as the only vegetable. Already, many regional farmers are extending their growing season with hoop houses known as “high tunnels,” keeping frosts at bay from leafy greens, carrots, and other crops. Good old fashioned root cellars and newer methods of storage help keep fresh crops longer into the cold months. Good keepers like apples, cabbages, potatoes, onions, and carrots can be savored from local sources well into March.
But there is yet another method that is finally coming into its own that offers year-round local crop production as well as an added bonus—fish! This method is called aquaponics.
Aquaponics is a merging of aquaculture (raising fish) with hydroponics (raising plants in water). With aquaculture, the problem lies in what to do with all the fish manure (called fish emulsion). In hydroponics, the trouble stands in finding a nutrient source, which typically is a chemical fertilizer. Aquaponics, as pioneered by Nelson and Pade Inc. of Montello, Wisconsin, embraces the idea that bringing the two practices together (in tandem with colonies of beneficial bacteria) eliminates the need for fertilizers while improving the conditions for the fish as well.
The fish (usually tilapia because they are a fresh water fish that grows quickly and enjoys warm water temperatures) swim happily in large tanks. The water from these tanks then flows through a series of filters and smaller tanks where the beneficial bacterial convert the nutrients into forms that plants can access. The plants live downstream in a network of floating Styrofoam rafts, plastic channels that the water flows through, or beds of clay pebbles with drip lines. Each growing environment supports different types of plants—from fresh greens and herbs to tomatoes, broccoli or radishes. These plants clean the water as it flows by, and the water is returned to the fish tanks. Once the system is filled, it requires 10 times less water per pound of produce grown than traditional field production.
What, local, organically-grown produce in the Northwoods all year? That is right! As we constructed our Creamery and Café, we built one of these aquaponics units housed in a majestic greenhouse alongside. Instead of 1,500 miles, your salad can travel just a few feet from greenhouse to table. Now that sounds more sustainable!
The aquaponics system has been an especially interesting project for my mother Ann, whose experience as a family physician brings acute chemistry savvy to the project. Yet between maintaining a sensitive balance of pH and nitrites, there are plenty of hilarious moments when the fish splash wildly, eager for their breakfast or joyous celebration as the first seeds pop out of their little growing cells.
Sometimes, we are asked why tilapia are chosen for aquaponics systems, and there are multiple reasons. The plants people like to eat enjoy a certain water temperature for growing, which happens to be the same temperature that makes these fish happy. Other fish species like walleye or salmon require colder temperatures, which inhibit plant growth. Tilapia are a wonderful fish for eating, especially when they are grown in such a clean, disease-free environment and fed high quality feed (which is mostly vegetarian).
In our system, the lofty greenhouse is filled with blue tanks, in different sizes and proportions, networked by PVC plumbing lines that took months to connect correctly. All this blue and white is now graced with green as the first generation of eager plants enter the drama. At the Café, you can now enjoy the first baby lettuce crop—so tender and flavorful—without any of the guilt of shipping it from far-off places.
Initiatives like aquaponics systems are part of developments in agriculture that embrace goals of enhancing local food security and diversity. The security aspect is multifold, from growing greens in a bio-secure, soilless environment (free from contaminants like E-coli, which cold-blooded fish do not carry) to building stronger local networks should long-distance shipping no longer be possible. These systems add diversity, in the form of clean, wholesome protein (fish) and a rich array of vegetables all year, free from chemical fertilizers, pesticides, fungicides, herbicides, etc.
Our aquaponics system is a little world unto itself, snug in the greenhouse as the autumn winds howl outside. Of course, the project did not start out this way, which was built mostly in late autumn and winter. With our contractor Jon Sorensen of Venison Creek Construction, we assembled steel rafters on the concrete slab in hats and gloves, puffing steamily as we hauled each rafter into place and secured the parts together.
The sides and ends were up, despite the instructions, and we were all set to put on the top covers…when it snowed. Not just a little snow. It was enough snow to keep the three of us digging for five hours straight, pushing and shoving the wet heaviness out the little back door. That was more than enough of shoveling out the inside of the greenhouse! It took a hearty crew of eight volunteers to hoist the top covers, which looked like great plastic sails. Too gusty of a wind, and we might have found ourselves in the next county.
At the time, it was hard to imagine that, only a year later, we would be growing optimistic little lettuces, ready for snipping and munching. We hope to be able to offer some of the first tilapia for sale in November.
Because of the emphasis on bio-security (where the objective is to keep germs, pests, and other problems out of the system rather than trying to remedy the situation later), we cannot give tours of the facility. Due to the transparency of the walls, though, it is easy to acquire an idea of the general workings of the operation from the outside, and we hope to develop a video tour for our website to give an “insider’s” feel.
Systems like aquaponics, which are built to serve specific community food needs, are part of the future of sustainable farming. This week, spend a little time learning how far your food has traveled, and see if there are ways to source your favorites closer to home. Everyone’s efforts are an important part of preserving our beautiful environment, which has been so gracious in sustaining us with nourishment, shelter, and wonder. And maybe we’ll see you down on the farm sometime.
Laura Berlage is a co-owner of North Star Homestead Farms, LLC and Farmstead Creamery & Café. northstarhomestead.com