The Statesman has a really in-depth article today about aquaponics, which (wiki definition) is “a sustainable food production system that combines a traditional aquaculture (raising aquatic animals such as snails, fish, crayfish or prawns in tanks) with hydroponics(cultivating plants in water) in a symbiotic environment.” According to the article, aquaponics is about 90 percent more water efficient than conventional agriculture, and three local farms are trying it out. Here’s an except:
In addition to Lily Pad, Ten Acre Organics and Agua Dulce have each staked a claim in the burgeoning practice of aquaponics, which may yield real environmental advantages for a dry climate like Austin’s. That’s because unlike conventional farming, plants aren’t rooted in soil, which dries out quickly. They’re planted in long, shallow pools of water, with fertilization coming not from soil nutrients, but fish waste.
“This is basically a really old practice of using fish in concert with plants,” says Jack Waite, owner/operator of Agua Dulce Farm, located in Dove Springs just across from a large apartment complex. Driving by, you can’t miss the colorful murals splashed across Waite’s food storage tanks: On one, a hand-painted sun spills forth a cornucopia of vegetables, which is, after all, the goal.
“Ancient Egyptians were doing this; Aztecs were doing this. The idea is that fish produce waste, mostly ammonia, which is toxic for most living things. But nitrogen-converting bacteria that exist in nature take that ammonia, convert it into nitrite, and then more nitrogen-converting bacteria turn that into nitrate. And nitrate, essentially, is super-charged plant food.”
So what does that look like in practice?
There are two chief structures on an aquaponics farm: fish tanks and greenhouses. The water from the fish tank is filtered for solids (e.g., fish poop), and that ammonia-spiked water is introduced into the greenhouse waters. To get a visual idea of these greenhouses, picture shallow, Olympic-sized swimming pool-length lanes with plastic foam rafts of plants floating on top, their roots dangling into the water from cut-out holes. Though there are various methods for nitrogen conversion, a farm like Agua Dulce’s encourages this process to happen all in the water — water that will eventually be cleaned and introduced back into the fish tanks.
“You lose 10 to 15 percent water from evaporation and transportation,” says Waite, “but that’s still better than traditional farming.”
How much better?
“Aquaponics is about 90 percent more water efficient than conventional agriculture,” says Lloyd Minick, co-owner of Ten Acre Organics.
“You can also grow plants much more densely, since the roots aren’t competing for soil nutrients. The fish offer a nearly endless supply.”
It all sounds pretty logical — even idyllic. More food, less water? Why aren’t more people doing this?
For one, the city of Austin doesn’t always know how to handle permitting requests like these. But Jake Stewart, who recently stepped down as the city’s Sustainable Urban Agriculture and Community Garden Program manager, says he thinks that’s changing.
“New is new, so when an inspector shows up, they don’t always know what they’re looking for in order to approve a project,” Stewart says.
“But we’re also one of the first cities to have urban agriculture and community gardens as an official approved use in almost every zone of the city, so momentum is moving in this direction. One where we encourage innovation around water. Water is our biggest challenge.”
There’s also the question of money. It takes significant capital to start up an aquaponics operation — just ask Harwood.
“Before I was doing this, I sold vintage cars in San Antonio and made plenty of money doing it. But I was looking for something more, you know? So I invested my life savings into this farm,” says Harwood.
check out the whole article here!