permaculture

["keller" <ak.and.ak@on-line.de>]

Well, I am just an interested layman. I have several books on aquaculture
and I have been reading a lot about it and possibly I will actually start
something in that direction in Africa, but as yet I don't have practical
experience in it myself.

> Thanks for the input. What is your thoughts on lining
> the pond with bentonite clay?

To seal ponds, there are several methods. It depends on the kind of soil you
have. In some areas, it is enough to compact the pond floor. This is how the
process is described:

"Compaction is the simples and cheapest method, and will usually work where
the soil contains a variety of praticle sizes, with at least ten percent
clay. For each soil there is a certain moisture content for optimum
compaction, so the weather plays a role in the success of compaction. A good
rule of thump is that a soil compacts best when it is too wet to plow but
not
wet enough to discharge water in the process of compaction. The first step
in compaction is to disk or rototill the soil to a depth of 8 to 10 inches
... The best tool for the actua task of compaction a a sheepsfoot roller,
but the wheels of a heavy tractor will do the job. I small ponds, a
lawnroller is a feasible but laborious substitute."

Dont ask me what a sheepsfoot roller is. The farming experts here in the
groop can probably tell.

This is what the book says about Bentonite:

"Perhaps the best known pond bottom sealant is bentonite clay, which absorbs
large amounts of water and expands to 8 to 20 times its original volume,
plugging up the pores in the soil. It is applied, preferabl, to the dry pond
bottom, at 1 to 3 pounds per square foot (5 to 15 kg/sqare metre) spread,
mixed and compacted as described above. (You will need a laboratory soil
analysis to determine precises dosage.) Bentonite is readiliy available and
not expensive, but immense quantities may be needed, so that, if you cannot
find a nearby source, shipping costs may be prohibitive. An added caution is
the occasional unexplained failure that occurs with bentonite. Some say the
ist is the low montmorillonite content of some bentonite which is
responsible, but I cannot confirm that."

There are other methods discussed, with chemical sealants and membrane
liners. The next section is more interesting from a pc point of view,
gleization:

"To use the gleization method, proceed as follows:
- Cover the pond bottom and sides completely with moist animal manure.
- Cover the manure layer with green vegetation, preferably broad-leafed
sorts. Paper or cardboard may also be used.
- Cover that with a third layer of soil.
- Moisten an compact, as described above.
- After several weeks, add water.
The process set in motion by the manure-green leaves-soil compaction process
involves creation of anaerobic conditions under which certain bacteria form
a 'biological plastic' called 'gley'. It is likely that the same sort of
process goes on at a slightly slower rate under plastic or rubber liners,
giving a fast, temporary seal together with a slower but permanent one.
Publication of an article on gleization in The Journal of the New Alchemist
... led to a number of responses describing variations on the mehtod. In
some casses, the animal manure was omitted, resulting in a slower, but
eventually effective reaction. Perhaps the most interesting response came
from Lee Shilling of The Folk Life Center of the Great Smokies, Cosby,
Tennessee. Lee reminded us that farmers in that region used to let their
hogs do the work for them. The pigs were simply allowed access to, and
perhaps fed in, a newly excavated pond. After a year or so, the resulting
combination of fertilization and compaction brought about a natural seal"

(let me stop the citation here before the author accuses me of copy right
infringement :).

Generally, after reading a lot about aquaculture, I get the impression that
there is a tremendous body of useful knowledge and that it will pay off to
delve into
the literature before you start practically. The same, I suppose, holds for
other areas
of farming.

Andreas

>
> I understand that trout are not pond fish. But I saw
> some trout in a small pond at the Holman Ranch in
> Carmel Vally. I was surprised. Maybe they were a
> special type of trout.

According to that book Trout "Needs flowing water for natural reproduction,
but can survive and gro w in suitable standing waters. Requires cold water
saturated with dissolved oxygen". So you would need to buy young fish, and
you need cold water. With rising temperature, oxigene solubility decreases.
Since you are in a hot area, trout is probably not the right fish for you.
There are other species that do fine and reproduce by themselves in warmer
waters.
>
> http://www.theholmanranch.com/openwedding.html
> "The Redwood Deck, just off the lawn, is reached via a
> small bridge spanning a trout pond."
>
>
> --- keller <ak.and.ak@on-line.de> wrote:
> > >    4) Build a natural pond with fish. Trout would
> > be cool.
> >
> > Hi,
> >
> > trout like it cool and prefer running water (high
> > oxigene content). Not a
> > typical pond fish.
> >
> > Tilapia could be the right thing, but they are
> > forbidden in some areas
> > (African family of fish, they multiply very quickly
> > and tend to push native
> > species out). But tilapia species might already be
> > present in your area, and
> > then why not grow them.
> >
> > I am not a fish farming expert, (no practical
> > experience myself) but
> > interested in the field.
> >
> > I recommend the following book:
> >
> > "Freshwater Aquaculture" by William McLarney. 1998
> > Hartley and Marks. ISBN 0-88179-123-7
> >
> >
> > What fish species do naturally occur in your area?
> >
> > Species to look at (some quotes from that book):
> >
> > Bluegill (Leomis microchirus)  "Probably the best
> > warm water insectivore for
> > North American ponds".
> >
> > Channel Catfish (Ictalurus punctatus) "The most
> > important commercially
> > cultured fish in the United States. Main culture
> > methods is intensive
> > monoculture in ponds, but also used in high and low
> > intensity polycultures,
> > closed systems, cage culture, farm ponds, trated in
> > Arkansas, Louisiana and
> > Mississippi, with some commercial culture in the
> > South Atlantic States, the
> > Great Plains states, Texas, California and Idaho."
> >
> > Bigmouth Buffalo (Ictiobus cyprinellus) " On of the
> > few large, native North
> > American filter feeders, and as such potetially very
> > valuable as a cultured
> > fish. Well suited for culture in rotation with rice.
> > Culture methods were
> > developed in Arkansas inthe 1950'as, but channel
> > catfish became much more
> > important economically. Mostly used in low
> > -intensity polyculture..."
> >
> > Filter feeders are low in the food chain, so that is
> > fine with respect to
> > food energy.
> >
> > Polyculture is something to read about! Different
> > fish occupy different
> > niches, some feed on plants, some on small animals,
> > some on feces of other
> > fish and dead plant matter, some on other fish
> > (don't dismiss theses: in
> > Tilapia, it the population density becomes too high,
> > fish tend to be
> > stunted. On way to solve the problem is some
> > carnivourous fish in the pond).
> > So pc-wise, that is the way to go. The chinese have
> > done it for thousands of
> > years, also integrated systems with aquaculture and
> > other things.
> >
> > Get some books, surf the web, find people who do it
> > (but not the commercial
> > guys, who feed the fish with all kinds of
> > non-organically grown things.
> > Normally, feeding them should not even be necessary,
> > since a pond in the
> > sunshine will produce quite some amount of biomass.
> >
> > Andreas
> >
> >
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