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three years ago, Stan Lyons, owner of Malamalama Farm in Honaunau, looked over his devastated coffee crop, lost to the cherry borer beetle, and asked himself, "What's next? I've got no water and no soil."
Seen the above the other day , in comments on the New Jersey article someone brought up Aquaponics .
Aquaponics is a specific arena of organic farming that is based on fish ponds and an enclosed hydro-circulation system. The foundation of Lyons' entire operation is a 5-by-10-foot fish pond that is 5 feet deep and built in cement and under cover. All the water for the system is from catchment, and fueled by 20 or so tilapia and koi that glide past in blends of orange, white and black. "In a true aquaponic system, you're supposed to eat the fish too," Lyons explained. "But we can't do that. These guys are our pets." In a typical aquaculture system, the pond water generates waste product from the fish. Aquaponics puts that by-product to work. Leading away by gravity feed from the pond, the water flows into a filter tank that divides the solid material and the water. That is the first stage of its nutrient breakdown. The bottom of the filter tank has a valve that allows the solid material to be collected. "This is incredible organic fertilizer. I put it directly on my raised beds and the results are phenomenal," Lyons added.
(Score: 1, Informative) by Anonymous Coward on Monday August 10 2015, @07:54AM
Thank you for the on topic post. Nitrogen and phosphorus Are supplied by the fish, potassium is a bit more difficult and usually requires supplementation. Supposedly ground up banana peels can work. Regarding fish food, one common option is to use a bug catcher/zapper above the pond, the caught insects fall in to the pond as fish food.
(Score: 2) by caseih on Monday August 10 2015, @02:03PM
No, the fish don't "supply" nutrients. They merely transform them from one form (food) to another (poop in the water) and concentrates them. Eventually if you run the system long enough without providing any of these nutrients into the cycle, you'll run out, particularly of P, and production will plummet. This is the problem with almost any current "organic" food production system.
In fact, when farmers sell food they are not only selling mostly water, but they are also selling a good amount of N, P, and K, all of which have to be replenished. I've read recently of several organic operations that run with no fertilizer of any kind that worked well for a long time, maybe 20 years, and then had production crash as the soil ran out of P, particularly. Right now the only real good source of P and K comes from minerals mined from the ground. When that runs out, there is no other good source of these nutrients at present. Maybe in the future farmers will require the nutrients to be sent back to them after the food has been consumed. Human and animal waste will have to be returned to the farms and put back in the soil.
I wish the article had more details on the complete nutrient cycle. From what I've read in most aquaponics at a certain point requires replenishing the phosphorous from mineral sources. N can be made from the atmosphere, but only by certain kinds of plants.