What Grows Here
by Rebecca L. Nelson
Controlled Environment Agriculture is a method of farming that embraces structure and technology to provide the optimum environmental conditions for plant growth on a year-round basis. Modern CEA greenhouses are light years ahead of hoop houses and cold frames. In a controlled environment greenhouse, the farmer utilizes features like natural ventilation and computer controls, automated shade systems, insect reduction and bio-security, dual and triple layer coverings, and alternative heating and cooling methods. This results in an ideal year-round environment for crops that is more energy efficient than many types of traditional agriculture.
CEA can also take place in buildings, using grow lights to replace sunlight, while maintaining the ideal temperature, humidity, and ventilation for plant growth.
Aquaponics is the combination of recirculating aquaculture (raising fish indoors, in tanks) and hydroponics (soilless plant culture). It is an integrated system that produces both fish and vegetables, continuously, without the use of growth hormones or antibiotics in the fish culture and without the use of pesticides, herbicides, or chemical fertilizers for the plant culture. In an aquaponic system, the fish waste, once it breaks down through the action of beneficial microbes, provides the nutrients that the plants need. The plants consume the nutrients, helping to clean the water for the fish. Aquaponics borrows equipment, methods, and benefits from both aquaculture and hydroponics, but is a unique, hybrid system on its own.
The process of aquaponics is truly natural, mimicking all waterways on earth. It differs from a lake or pond, though; in aquaponics growers stock the fish in tanks and plant the plants closer together to maximize how much can be grown. The beneficial bacteria in an aquaponic system are the same bacteria as in an organic garden. In aquaponics, they break down the fish waste into the individual elements that the plants need.
Tilapia, a fast-growing, fresh water fish, is commonly raised in aquaponics because it is hardy and good tasting when raised in clean water. Other fish, such as bluegill, catfish and trout, are sometimes raised in aquaponic systems as well. Most garden crops, such as lettuces, greens, tomatoes, cucumbers, peppers and beans can all be raised easily in aquaponics.
There are some inputs in aquaponics, including fish food, energy, and fresh water. The fish need to be fed a quality, complete diet so they are healthy and their waste provides the nutrients the plants need. We need electricity to run water and air pumps and for heating and cooling, depending on climate. Fresh water is needed to replace what is used by the plants during transpiration.
Aquaponics + CEA = Growing Fresh Fish & Vegetables, All Year
CEA combined with an aquaponic system, allows a grower to produce premium quality crops on a year- round basis, maximizing production in a given space.
The biggest advantage of using CEA combined with aquaponics is that one can continuously grow and harvest food in any climate—and, do it with less water, space, and labor than traditional farming, all the while producing both a protein (the fish) and vegetable crop. Soilless plant production systems eliminate soil, which eliminates most soil-borne disease.
A fully integrated, science-based commercial aquaponic system in a controlled environment can grow six times more food on one-sixth of the water than outdoor soil farming.
Working in a controlled environment aquaponic greenhouse, surrounded by beautiful plants and fish, is a very enjoyable activity. The green plants, oxygen-rich air, and comfortable year-round temperature provide therapeutic value and comfort for those who work there.
Heather Hutchinson, aquaponics greenhouse manager at Nelson and Pade, Inc. a commercial aquaponic greenhouse in Montello, Wis., commented, “It is fast-paced but relaxing all at the same time! As a manager I’m working to meet delivery deadlines to keep our customers happy, but the atmosphere in the greenhouse has a calming effect, which makes the work enjoyable and keeps the stress level low. Being able to see fish happily swimming, hear water flowing, feel the breeze and tend to plants growing every day, all year long, is fun. It’s also very rewarding because I cared for those fish and grew those plants that look and taste amazing. There’s a real sense of pride and accomplishment associated with managing an aquaponics greenhouse.”
Aquaponics at Island Grown Initiative
On Martha’s Vineyard, Island Grown Initiative (IGI), a non-profit that supports sustainable agriculture, local food advocacy, and education has embarked on a large indoor farming effort, which began with the purchase of the Thimble Farm greenhouses two years ago. The 30,000 square-foot greenhouse facility was formerly used for hydroponic tomato production. Keith Wilda, executive director of IGI and manager at the Thimble Farm greenhouse, and the IGI team spent the first six months cleaning out and preparing to repurpose the greenhouse.
The original structure had glass roofing and walls, which provided light penetration but had high energy loss. To increase energy efficiency, step one was to cover the north and east walls with 5 1⁄2 inch thick insulating panels. This thermal blanket provides addi- tional heat retention in the winter and shading in the summer, further reducing energy costs.
Currently the greenhouse is home to various types of soilless plant production systems and plant crops as well as a 5,000 square-foot fish room, housing two large tanks in which rainbow trout are farmed. The trout in the tanks produce waste, which is used in a limited amount in aquaponic systems. A separate gray water stream from the trout culture is used as the source water for the 22,000 square-feet of organic hydroponic plant production.
Keith explained that they are currently growing 26 different varieties, including peas, carrots, artichokes, tomatoes, peppers, cucumbers, beets, pak choi (bok choy), strawberries, kale, spinach, red mustard, and more. Keith added, “We are trying to run the farm more like a farm-hub. In the next five years I’d like to see this greenhouse used by more Island farmers.” In a location like Martha’s Vineyard, it is often less costly to build a greenhouse than to buy land to farm. The IGI greenhouse is demonstrating this, as well as the value of sustainable farming efforts to help to build a food system.
Aquaponics Appeals to People Around the World
Aquaponics is attracting people around the world due to the simplicity and naturalness of the system and the quality of the fish and vegetables grown. Many hobbyists and backyard aquaponics practitioners are building or buying aquaponic systems so that they can provide fresh food for their families. An aquaponic system in a 500 to 800 square-foot greenhouse can provide all of the fresh fish and salad crops an average family would consume.
Entrepreneurs are attracted to aqua- ponics as a business venture that is both economically and environmentally sustainable. BJ and Cat Davis, of Camp Verde, Az., started a commercial aquaponic business to supply local restaurants and markets with fresh, naturally grown fish and vegetables. Both retired professionals, they thrive in their new roles as aquaponic farmers and love spending time in their controlled environment aquaponic greenhouse. Cat Davis said, “At The Fish’s Garden in Central Arizona, we grow fish and produce for sale to our local restaurants. With the success we are experiencing using our Clear Flow Aquaponic System®, it has become evident that we will be able to expand two years sooner than we originally expected.”
Another very popular use of aquaponics is taking place in schools around the world. Educators love to incorporate aquaponics into the classroom because it teaches biology, plant science, earth science, horticulture, engineering, mathematics, agriculture, and more. Plus, caring for the fish and plants instills a sense of responsibility and an interest in fresh food and nutrition.
Burke Smejkal, an educator at Baker Technical Institute (BTI) in Baker, Ore., writes, “We are using an aquaponic system as a foundation for learning about the exciting and engaging science of aquaponics. High school students are able to learn a variety of concepts related to science, technology, engineering and math (STEM) with contexts in plant and fish science, food safety, global food security, local food production, agricultural and bio- logical engineering, water chemistry/ quality, and systems science to name a few. Our aquaponic system has also exposed students to new innovative career pathways in agriculture, science, and engineering.”
The Aquaponics Industry
Controlled Environment Agriculture, aquaculture, and hydroponics have been in existence for many years. The combination of these technologies is coming together as more and more individuals, educators, and businesses looking for a sustainable path to better food discover aquaponics.
In recent years, the application of aquaponics and the number of commercial aquaponic farms has grown exponentially. The desire for a consistent supply of high quality, sustainably and locally grown food is driving this growth.
The aquaponics industry is currently in transition, from small scale, low-tech start-ups to much larger, more professional installations using controlled environment agriculture. Like any business venture, an aquaponic farm needs proper planning, sufficient investment, and excellent management and marketing. New aquaponic farms today that are having an impact on food availability and quality need to demonstrate food safety, good agriculture practices, and bio-security.
To embark on an aquaponics project, big or small, it is important to gain enough knowledge to do it successfully. There are professional level aquaponics courses offered in the U.S. As a small but growing industry we have an excellent and ever-expanding base of scientific research as well as real-world applications that we can build upon.
Although aquaponics is barely on the radar of large-scale agriculture, it is rapidly gaining popularity and having a positive impact on food security, food quality and availability.