[permaculture] pc aquaponics
KAKerby at aol.com
KAKerby at aol.com
Mon Oct 8 09:09:13 EDT 2012
But have you actually LOOKED at any of the research being done? As I
pointed out, lots and lots of university research being conducted right now in a
lot of different aspects of this approach, and yes nutrient density of the
resulting plant tissue is right up there. Brix measurements can be as
high or higher than the finest organic stands of soil-based agriculture for
leaf tissue. Complex nutrient density is present if it's present in the
system, and missing if it's missing from the system (just like soil-based ag,
where crops forcibly grown on tired out soils are going to be missing a lot
of nutrients). It's assumptions like this that are so very limiting. The
same assumptions were made about organic ag not 10 years ago - "it's no
more nutritious so what's the point"? If the nutrients are in the system,
the plants will pick them up. If the nutrients aren't there, they won't.
That's not a function of whether the plants are growing in a soil or
soilless media. That's a question of whether the nutrients are in the system as a
whole. I've seen a lot of dead soils on working farms. I'd rather take
food for my table from a system I know is balanced and working with healthy
plants and fish, rather than produce from those over-mined soils with a
history of herbicide and pesticide reliance. And a lot of folks have no way
to measure how tired out the soils were, which produced the food they eat.
Presuming that soil-based is better, is ignoring all the problems in
And before folks start talking about "yea, but you have to introduce those
nutrients, so it's artificial", I would point out that's true for many of
the world's soils as well. We have to supply a variety of trace minerals
such as selenium to our soils, to bring them into balance and keep them
there. Does that make our soil-based farming unnatural? Does that make
farming in whole regions with depleted soils, such as Australia, simply
unnatural? Or is that simply a reflection that no soil, anywhere, is perfectly
balanced? And even if our soils are perfectly balanced for that particular crop
at that particular time, they won't stay that way. We'll have to
introduce some method of bringing those withdrawn trace nutrients back to our
soils, as they are removed by the crops and the crops removed from the system
(ie, eaten or sold). So from that standpoint, soil-based and soilless ag are
the same. The methods used to introduce those trace nutrients are the
same as well. Both systems have the choice to use natural or artificial
supplementation. With aquaponics however, you have immediate negative feedback
if the supplementation is too harsh, because the health of the fish will
suffer. In soil-based ag, many times the farmer has no indication of
long-term issues at all. The folks downstream might not know it for years or
decades to come.
Another objection to aquaponics is that folks believe it's missing the rich
web of microscopic life that is found in healthy soils. Again, have you
actually LOOKED for information on that? One of the most exciting
developments for both hydroponics and aquaponics is that proactive innoculation
with beneficial bacterial and/or fungal colonies works just as well in soilless
ag as it does in soil-based ag. That discovery was made over a decade
ago, and has become a fundamental part of disease prevention and nutrient
update for those growers who are interested in really giving their plants all
the tools available. Much like it's been a tool for soil-based growers for
millenia, but not everyone takes advantage of that option. If that sounds
artificial, does that mean soil-based ag should stop innoculating the soil
for things like peas and lentils, alfalfa and beans? It's more familiar
to us because it's been a part of soil-based ag for generations. But don't
assume hydroponics/aquaponics doesn't have that option too. It does, and
it's being used just as beneficially.
To make blanket statements about what aquaponics can and cannot do, or
produce, or solve, without actually working with this approach or reading the
research materials and day-to-day working results for those using this
system, is head-in-the-sand behavior. If you doubt something about it (or any
topic), GO LOOK for information on it. You might be surprised at what you
In a message dated 10/8/2012 4:28:19 A.M. Pacific Daylight Time,
venaurafarm at bellsouth.net writes:
On 10/8/2012 1:15 AM, christopher nesbitt wrote:
> Thank you for this. Its funny that aquaponics, one small practice,
> generates so much naysaying. I have seen this often, and the
> arguments all tend to be the same: its not natural, or: it cannot be
> balanced if it is not coming from soil, and: It is capital intensive.
> Thank you, Kathryn, for pointing out the obvious: aquaponics lends
> itself to extremely localized food systems. No food miles is a good
The problem as I see it is that as far as I know you can not grow food
with the same nutritional value (vitamins, minerals, etc.) in an
aquaponic or hydroponics system as you can growing those same crops in
soil that has been properly nutrient/mineral amended and balanced.
That is what Scott is saying and I say the same. I would not hesitate to
eat food grown in an aquaponic or hydroponic system but I would not make
that my only source of food and would require that most of my food be
grown in soil, of adequate quality.
I doubt anyone is naysaying aquaponics; it has too much to offer and is
a resource truly within the realm of permaculture.
> Kathryn said: "
>> I also question whether a farm that grows in soil, but trucks in
>> all its supplies and trucks out all its produce, is "better" than
>> someone who raises food via aquaponics in their backyard with 1/10
>> the space, 1/10 the water, 1/1000 of the petroleum, and by the
>> system design, can't use pesticides or herbicides.
You are what you eat. In principle the aquaponics is much better from a
carbon footprint point of view and a lack of pesticide residues but a
person has to get complete nutrition. Unless I am shown otherwise I
can't see aquaponics providing all a person needed year after year, only
part of what you need. You will have to get the rest from soil grown
crops. Why can't you irrigate outdoor gardens with part or all of the
aquaculture effluent? Do both on the same site, one backs up the other,
all are "locally grown", low carbon footprint.
This is a great topic to discuss. I hope it will continue. Remember The
New Alchemy Institute, John Todd and staff? They got the ball rolling
> 1/10the water use? 1/10th the space? 1/1000th the petroleum use?
> Can't use pesticides or herbicides? That sounds pretty good, to me.
> Scott asked:
>> in this closed system, where does the selenium, calcium and
>> phosphorous come from?
> Perhaps part of the problem you have with aquaponics, Scott, is that
> you, like many who naysay, do not understand aquaponics. The system
> is NOT closed. You are bringing food to the fish, and taking veggies
> out. That is a linear system. The only "closed" aspect is the water.
> While the water recirculates, you have inputs in feed, wether you
> make your own, raise your own or buy Purina Aquaponics Chow (which IS
> a problem), and remove herbs, veggies and fish from the system. Water
> leaves the fish tank laden with some manure, and returns filtered by
> the gravel, bacteria and plant roots, oxygenated.
> Amongst its many attributes, one of the ones that impresses me is
> that it is highly productive. Joel Malcolm produced over 100
> kilograms of veggies and herbs, over 50 kilograms of fish, in an area
> 4x8 meters, in six months. That is a staggering amount of food, in
> just veggies and herbs, alone. Considering the fish, thats
> So, is it balanced? that begs the question: What are you feeding your
> fish? If the source of your fish is worms from your land, or black
> soldier fly larvae from compost from your land, or from a bug zapper
> placed over the tank, or from raised mosquito larvae, or from
> tadpoles, or from algae, or, if you are making pellets from egg, rice
> bran, coconut, moringa leaf, acai berry, noni, chicken parts
> (organically grown, and butchered on site), and the soil that comes
> from is balanced, then... the mineral content of the fish manure
> should be balanced in minerals. The mineral content of your fish dung
> is tied to the mineral content of the what you are feeding them.
> In an on line evening discussing aquaponics, a group of people came
> up with "decaponics", which was a series of energy and nutrient flows
> built around aquaponics. There were 10 components. As I recall, in
> our free for all design, we penned in rabbits, sheep, a piggery with
> biogas plant, ducks, vermicomposting, spirulina production, and some
> other things. I forget. I think a bug zapper was over the fish tank.
> The papers are somewhere. The point is that aquaponics can be tied
> into larger things.
> In a world of expanding populations, soil depletion and loss of
> farmland, NOT considering aquaponics seems to me to be discarding a
> useful tool. To me, clearly aquaponics has a role to play.
More emphasis needs to be placed on local biointensive food production
on suitable land. Aquaponics has an important place in such systems. Why
not emphasize protein production in aquaculture systems? Feed the
effluent to the gardens but retain enough to provide nutritional needs
of an aquaponic system in a greenhouse to help ensure a year-round food
supply. Valuable cash crops can be grown this way, some food, some other
(legal ones). What about growing baby ginger, galangal and turmeric in
an aquaponics system of one that uses soil constantly irrigated with
aquaponics effluent. Make sure harvested crops are clean
before using or selling them.
> Again, in a situation, like in an urban setting, or where soils are
> either depleted or contaminated, or where inadequate water is
> available to produce in soil, producing out of season veggies
> locally, either from home use or for commercial use, in a world of
> increasing costs of transported food, aquaponics has plenty to offer.
> It is not THE solution, but, in a nuanced world, it is A solution. As
> I mentioned, earlier, having a biological filter comprised of gravel,
> bacteria on the gravel, and plant roots, allows for high stocking
> densities of fish. High stocking densities of fish being filtered
> through bacterially colonized gravel, with plant roots, enables
> people to produce veggies with no petroleum miles on them, lots of
> veggies and fish, in a small area. The only cost is the initial
> energy to build the system, and the electricity to run it, and, of
> course, the energy to source your feed.
Join the compost tea list. There is much to learn on this subject
(aerobic/anaerobic/bacteria/fungi/nutrients and minerlas/etc from that
friendly commmunity. Its the compost_tea list at yahoo.
> As Kathryn and I have said, aquaponics is one tool to have in your
> tool kit. It is not THE answer, but it is a solution to a fairly
> large set of problems. I would not relegate soil based agriculture to
> the dust bin of history, hahahah, and I still farm a lot of land,
> over 25 acres, now, a full on food forest, with over 500 species, but
> aquaponics has huge potential, and I am looking forward to working
> with our system. I intend to add the occasional cup of compost tea to
> our system, for fungal communities.
> Lastly, Scott, I wasn't going to throw in mangrove. In the last 12
> years, I have done a lot of work for Fisheries Dept installing
> photovoltaic systems in seven marine protected areas. Mangrove, like
> most "edges", is very productive, in fish and crustaceans, birds.
> Apart from "coco plum", and "sea almond", not much food can grow in
> mangrove, and none can in red mangrove, which is the species of
> mangrove that grows directly in salt water, here. White mangrove and
> black mangrove prefer sandy soil. Belize has %3.4 of it's territory
> in mangrove. That is still %98.7 of its colonial spread. In Belize
> mangrove is protected. Its not really a good analogy to chinampa or
> rice paddy, as you pointed out. I am not sure why you brought it up.
Read my reference to what is being done with sustainable mangrove
forestry in Eritrea. It fits in perfectly with local sustainable
food/fiber/livestock feed systems with stacked functions.
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