Can we grow crops using 90% less water?

Aquaponic farming at Ouroboros Farms in Half Moon Bay, CA (Image courtesy of Ouroboros Farms)

High-end chefs love it.  Enthusiasts are calling it the future of agriculture.  Environmentalists tout it’s sustainability.  Aquaponics—the practice of using fish to fertilize crops grown in water—may provide a solution for growing food in an increasingly dry Western climate.

Lettuce, mustard greens, Swiss chard, and kale cultivation (Image courtesy of Ouroboros Farms)

What is aquaponics?

While it might seem like something out of Interstellar, the practice of using fish to fertilize crops grown in water has been around for centuries. The materials have gotten far more high-tech, but the concept behind the system is largely unchanged.

Swiss chard roots (Image courtesy of Ouroboros Farms)

Plants are cultivated in grow mats above water, while fish are farmed either below or in connected tanks. The fish are given organic feed and then leave nutrient-rich waste which becomes fertilizer for the plants. The plant roots, in turn, filter the water to keep a healthy living environment for the fish.

Fish provide organic fertilizer for the greens (Image courtesy of Ouroboros Farms)

How aquaponics saves water

I never would have guessed that farming—using huge tubs of water in lieu of soil—could dramatically save water. But some aquaponics famers have cited being able to use up to 90% less water compared to traditional agricultural methods. When crops are grown in soil and irrigated, much of the water that is not immediately used by the plant is lost in evaporation and drainage.

Fish tanks connect to grow tanks at Ouroboros Farms (Image courtesy of Ouroboros Farms)

In contrast, there is almost no evaporation in aquaponics systems, save for some evaporation of the tank water and transpiration from the plants themselves. Plus, the plants can uptake as much water as they need and have 24/7 access to organic fish-waste fertilizer. Instead of expending energy to establish deep root systems to search for enough water, the plants put all of their available energy into growing leaves and fruit. All of this leads to vegetables growing about 30% faster in aquaponic systems.

Lettuce harvest at Ouroboros Farms (Image courtesy of Ouroboros Farms)

How it all adds up

Is aquaponics the solution for agriculture for the drought-stricken West? No. Given the high cost of set-up of an aquaponics farm, we’re not expecting aquaponics to replace traditional agriculture anytime soon. However, the opportunity to use aquaponics to cultivate food in areas that are unsuitable for traditional agriculture—urban environments, areas with contaminated soil, or desert locations—could prove to make a positive impact for sustainable agriculture.

Greens are all washed before shipping to restaurants and consumers (Image courtesy of Ouroboros Farms)

Learn more

If you’re interested in learning the basics of aquaponics, Ouroboros Farms is holding beginning workshops this fall (September 26th, October 24th, November 21st, and December 19th) in Half Moon Bay, CA. Workshops include a hands-on demonstration of aquaponics, how to set up a system, and a tour of the Ouroboros Farms. Supplies are also available online.

Not ready to dive into a full-on aquaponics workshop but curious to know why chefs love the produce? Ouroboros Farms greens are available from Good Eggs, including aquaponic baby lettuces, mesclun mixes, cress, and basil.

For more backyard-scale aquaponic set-ups, check out EZ Aquaponic Kits which offers vertical aquaponic drums, tank-towers, and other systems.

For Colorado readers, the Denver-based Grow Haus is an excellent resource for learning about aquaponics and sustainable agriculture. In addition to workshops about aquaponics, they also offer courses on beekeeping, sustainable garden design, and permaculture. Check their online schedule for more details on fall workshops.