-The Future of Agriculture
words by Jackie Dale • image by Frankie Leal
Dana Ritschel of Reedley has an interesting and unusual hobby. He is a backyard aquaponics farmer. So what exactly is aquaponics? The word “aquaponics” is what is known as a “portmanteau,” a blending of two words to form a new word. “Aquaculture” is the raising of fish, shrimp, or other water creatures. Hydroponics is the raising of plants in water, sans soil. Aquaponics is the symbiotic combination of raising fish whose waste provides organic nutrients for growing plants.
Some camps claim the Aztecs were the first aquaponic farmers while others give that credit to the Chinese. Modern aquaponics methods are usually attributed to the research and development at the New Alchemy Institute. In 1977, Dr. James Rakocy and his colleagues at the University of Virgin Islands perfected the system of deep water culture hydroponic grow beds in a large-scale aquaponics system. With farmland dwindling in the face of ever increasing development, and the current water crisis, aquaponics may be a realistic and viable option for growing food.
Large commercial aquaponics farms can be found all around the world, including several here in California. The backyard aquaponics farm is rapidly gaining popularity among people who wish to grow their own vegetables and for whom land/soil and/or water, may be an issue.
Dana falls into the latter category. While he dreams of a commercial aquaponics farm, reality dictates that Dana keep his day job as an engineer for Fresno County and work his aquaponics farm on a smaller scale. A huge tent-like greenhouse in his backyard contains his operation. While the greenhouse is not necessary, it keeps things clean and out of the elements. A couple of times now though, thieves have cut through the greenhouse canvas. Since nothing was taken, Dana surmised that the thieves were obviously not after some salad fixings. Dana laughed as he said how he imagined how disappointed the thieves must have been to only find vegetables growing there.
Growing plants in water uses astonishingly 90% less water than traditional irrigation of crops grown in soil. That is a huge plus in a drought stricken state. There are no worries about weeds, soil borne pests or critters eating your bounty. There are no chemicals or fertilizers to worry about. In addition, the toll on the body from working a traditional garden is eliminated. No more aching backs or sore knees from kneeling and bending. The waist high tables provide for a strain-free work environment. Another plus is a shorter growing period. A crop that typically takes 60 days to mature can be harvested in 52 days using the nutrient rich aquaponic system.
Upon entering Dana’s greenhouse the first thing you notice are the two huge tanks, one contains water only and the other one is full of fish, mostly carp and catfish. Dana has city water so he must let the chlorine in it burn off before he can use it in the tank containing the fish. Dana turns off the pump and the fish immediately come to the surface. “They know when the pump goes off, it is feeding time,” said Dana. “Fish are quite easy to train,” he added. The fish waste falls to the bottom of the tank where gravity pushes it through air stone. It is then piped over to a big barrel called the swirl filter. The water swirls around sending the big waste to the bottom and the “clean” water is pumped into a deep table filled with air stone rocks. The rocks are where all of the biological activity takes place. The microbes (nitrifying bacteria) and sometimes, red worms, which Dana plans to add soon, convert the ammonia from the fish waste into nitrites, then nitrates, which the plants utilize as nutrients.
That water is then pumped into the long growing tables. Floating on the water are big pieces of styrofoam-like boards called “blue boards.” They are painted white to protect the foam and reflect the light. Holes are cut to hold the plants. The seeds are placed in a small container containing a mixture of vermiculite and perlite. The containers are placed in the holes and the roots grow out through the large openings in the cup. Electrical usage is negligible. Dana uses 4 small pumps to move the water, and in the summer, several fans to keep the greenhouse reasonably cool. The sides of the greenhouse can be lifted for more light and better air circulation. The water eventually returns to the fish tank, completing the recirculation cycle. Some water must be replaced to compensate for minimal evaporation as well as to replenish the nutrient rich water the plants “drink.” There are no chemicals of any kind used. Even so-called organic chemicals are off limits because of the fish.
One limitation to aquaponic farming is that you only get the nutrients that the fish produce. Therefore you must supplement the magnesium, iron, calcium and potassium. Dana does this with seaweed extract and seaweed iron. Some plants like tomatoes don’t fare so well in aquaponics because they require more nutrients than are found in or can be added to the aquaponic system.
Dana would like to sell his produce at farmer’s markets but currently lacks necessary certification. So Dana’s friends and family are very happy to be steadily supplied with a virtual cornucopia of vegetables from his little farm. Crops are rotated depending on the season. Dana recently finished harvesting a bumper crop of kale. Kale does exceptionally well in an aquaponic system as does lettuce, eggplant, swiss chard, parsley, green beans, sweet peas, okra, cucumbers, zucchini and chili peppers. His serrano peppers alone yielded over 15 pounds of peppers. Dana said he must have given away over 30 bags of kale. Strawberries are innovatively grown overhead in rain gutter-like containers. A small beehive in the corner performs the pollination duties required for some plants like the cucumbers. Marigolds and nasturtiums are grown specifically to attract whiteflies and aphids away from the vegetables since again, no chemicals are allowed for pest control. Nothing is wasted. Vegetables that go to seed are saved and used for the next grow season. Dana takes his excess or over-ripened produce to his uncle who feeds it to his chickens and rabbits. In return, Dana gets fresh eggs.
Dana enjoys giving tours of his backyard farm on the weekends. He meets other aquaponics farmers, or those interested in aquaponic farming through www.meetup.com where they swap stories and share tips as well as offer advice and encouragement to those interested in becoming aquaponic farmers. Dana stresses that aquaponics farming can be done on even the smallest scale. Some people use barrels instead of large tanks. Dana laughingly said that you could literally grow herbs over your fish tank.
Getting the aquaponic system set up can be challenging, but once up and running, it is fairly low maintenance. Large amounts of food can be produced in a relatively small area. Aquaponic farming might just be the wave of the future in farming fresh, organic produce.