Does Aquaponics offer all the Nutrients that plants need?

[Castaway]

Here's a question that gets asked of me privately by a lot of Permaculture people of Aquaponics. "Are all the nutrients that are needed by the plant grown in Aquaponics available to it?"
The idea is that in an "organic" dirt garden has a plethora of nutrients available to the plant at any moment. The perception is that there are few if little available to the plants grown in an Aquaponics system. This question is raised continually by people who are a little suspicious of things grown in tubs and out of their soil environment and I saw this question raised again today on one of Murray's YouTube videos.

The reader asks politely:

"I am all for organic and chemical free but when it comes to acquaponics, do the plants receive *all* the nutrients they really need? Soils have an enormous number of elements to them. Despite the artificially created tastes made by the advertisers, variation is a god thing - especially if you are allowing the plants to take up as wide a variety of nutrients as possible. The plants know what they need the best in any given environment.

Does anyone know if acquaponics accounts for this?"

A good question.

Any one care to respond?

[Neil Bell]

I dont know the answer to this but can anyone say that the soil they are using has all the ingredients the plant needs. Every type of soil is different. Good soils grow good plants bad soils dont, so I guess its best to leave the talking up to the plants. If they like it they will grow well, if they dont then you get poor results or they die.

Not much help but thats my thoughts.

[dufflight]

In Ap systems we add sea salt and seasol so there are more trace elements than most soils. And with worms mineralising waste in the GB's, in greater numbers than soil. And the plants growing faster and looking and tasting better, my guess is if we are missing something its probably not needed any way.

[RupertofOZ]

Originally Posted by Castaway

Here's a question that gets asked of me privately by a lot of Permaculture people of Aquaponics. "Are all the nutrients that are needed by the plant grown in Aquaponics available to it?"
The idea is that in an "organic" dirt garden has a plethora of nutrients available to the plant at any moment.

I think the idea that a dirt garden "has a plethora of nutrients available to the plant at any moment".... is both a fundamental fallacy... and at the same time... an answer to the question...

Dirt gardens have a periodic... and unregulated "flood & drain" regime... i.e rain... and as such, most of the nutrients needed, which are water soluble and motile.... are often unavailable... unless a watering regime is in place...

Similarly, the whole concept of "companion planting"... besides disease/pest considerations... is based upon the understanding that certain plants have different nutrient needs... and that one plant might deplete the needs of another etc...

Then there's the whole "fertilising"... and crop rotation philosophies.... to replenish and provide the necessary trace elements/nutrients...

That a plant "needs available at all times"....

In aquaponics.... we meet all the nutrient needs... of all the plants.... all the time.... within limits of pH lockout of things like iron...

[Murray]

We could go on for hours about this I am sure, but I feel it has been answered in the three previous posts.
How could comparison scientific trials be done ? It would be difficult.

Gardening of any sort is almost a religious experience....people develop a strong belief that their particular gardening method is the best. Maybe that is not such a bad thing, but strongly held belief systems can sometimes limit logical thought.

I have been asked the same question as Castaway outlines, every single time I have presented AP at a Permaculture gathering.
I find that once these people understand just how AP works, particularly a closed loop model such as most of us practice ....flood and drain with worms etc....these folk quickly understand and become just a little excited at the possibilities that a AP system inclusion will bring to their Permaculture vision.
AP inclusion will bring even more balance to an overall food production system, as will the inclusion of wicking beds and so on.

There are a couple of mental barriers to AP, in the minds of Permaculture type purists.
One is the soil....you must have soil with worms and compost to have a proper garden.
Two is the fish food....commercial pellets are made from by-catch and the making and using of them is destroying the ocean fisheries, which is seen as ecological vandalism and unsustainable.

I believe these barriers can be and are being dealt with very effectively and we will see a gradual shift in attitude, and AP will be seen as a very viable and even necessary part of a Permaculture plan/garden...

[TheNative]

The name aquaponics can be deceiving. The hydroponics portion of the name implies growing solely in water but in a way, aquaponics grows in water and soil. Dust from the air and other sources will find it's way into the GB. Fish waste will break down into an organic fertilizer that together with the dust and dirt will create an organic soil in the GB. With a regulated flood and drain cycle the plants will also have all the water and air they need, without the loss of water one would expect from a soil garden.

As far as by catch goes, it's better we use it or else it goes into a landfill.