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permaculture - Re: [permaculture] Exotic Plant Eradication - Uses for water hyacinth - Las Gaviotas project

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  • From: lfl@intrex.net
  • To: permaculture@lists.ibiblio.org
  • Subject: Re: [permaculture] Exotic Plant Eradication - Uses for water hyacinth - Las Gaviotas project
  • Date: Fri, 30 Aug 2002 02:28:39 -0700

lfl@intrex.net wrote:
Kirby Fry wrote:
I saw the pics of the water hyacinth and thought, "that's more of a
solution than a problem" <<
I tend to agree, they produce incredible amounts of biomass and pull the
nitrogen out of the water column, plus they're beautiful. I was talking to

That we (those in the permaculture community) are glad for the presence of
exotics and woody plants sets us apart from the aggies and native plant
societies. It's a distinction I'm proud of and have had several
conversations with Bill Mollison about.

Las Gaviotas
http://www.zeri.org/expo/prj_gaviotas.htm

Water Hyacinth Is An Opportunity In Disguise
http://www.zeri.org/expo/prj_hyacinth.htm

Quoted from their website:
--------------------------
"The African lake districts have an abundance of the waterweed commonly
known as water hyacinth (Eichhornia crassipes). This aquatic weed
has become a serious problem because it grows very fast and in the
process chokes up waterways, blocks navigable waterways, reduces
fishing points, and in some cases blocks water pumps. In Zimbabwe,
Chivero Lake became choked to the extent that the water hyacinth
mat could support human weight (Machena, 1997). The adverse impact
of the excessive growth of the water hyacinth is being felt in the
economies of all lake districts of Africa including Zimbabwe, Malawi,
Zambia, Tanzania, Kenya, and Uganda.
However, water hyacinth has a unique capacity to absorb and concentrate
massive amounts of inorganic minerals dissolved in the water mass.
As a result of this special charactersistic, the biomass can serve
as a productive resource for mushroom cultivation.
A year later Professor George Chan and Professor Mshigeni visited
Malawi to discuss with scientists from Bunda College of Agriculture
of the University of Malawi. Mr. Pauli and Professor Chan later
visited Tanzania for the same purpose. Under the ZERI vision, the
great water hyacinth problem came to be seen as a great opportunity.
The Tanzanian Commission for Science and Technology and colleagues
at the University of Dar es Salaam, all support the vision of promoting
the harvesting and using of water hyacinth as an agro-fertilizer,
as a livestock feed supplement, as a substrate for raising mushrooms
and earthworms, and as a source of biogas energy. These uses provide
both an immediate and a long term solution to the problem.
Oyster Mushrooms:
Scientific research initiated by Margaret Tagwira for ZERI Foundation
demonstrated that dried water hyacinth is the best substrate for
farming mushrooms. This program directed by Prof. S. T. Chang, an
authority on the matter, confirmed that the water hyacinth is a
blessing in disguise. Sociological studies confirmed that nearly
all African cultures had mushrooms as a part of their diet. The
spent substrate after fungi harvesting is rich in protein from the
mycelia of the mushrooms and are excellent feed for earthworms,
which convert it all into humus and can be fed to chickens, ducks
and pigs.
Under the guidance of Professor S. T. Chang, a viability study
was undertaken in the Southern Africa Development Community (SADC)
region: Malawi, Namibia, Tanzania, Zambia, and Zimbabwe. A group
of scientists reconvened after the first meeting at the African
University in Mutare, Zimbabwe, and under the co-ordination of Mrs
Margaret Tagwira, the initiative moved forward.
The System:
After only 30 days, the dried substrate from water hyacinth produced
a variety of mushrooms. Once harvested, it did not take more than
ten days to harvest a second and even a third flush. One hundred
kilograms of dried water hyacinth generates more than 100 kilograms
of mushrooms. The water hyacinth outperforms traditional substrate
materials such as sawdust. In addition, since the substrate of water
hyacinth is rich in minerals and nutrients, the oyster and straw
mushrooms cultivated ended up enriched with potassium, magnesium,
iodine and calcium, along with numerous other components that are
critical to a healthy food diet. Much of what was lost in the form
of washed away topsoil can be recovered in the mushroom. The water
hyacinth can also recover harmful metals such as cadmium and lead
and store them in their roots if these metals are found in the rivers
or lakes.
The residual substrate of water hyacinth after mushroom farming,
is a rich food-base for cattle. Since nearly all the lignocellulose
has been broken down by the enzymes of the mushroom, the rest of
the material can also be used to farm earthworms, which will convert
the material into a humus. The humus that is produced in the process
can then be reapplied to the soils, recovering and replenishing
some of the lost topsoil. The earthworms can be used as high protein
chicken feed.
The cycle of biomass around the water hyacinth also allows for
the production of biogas generated from the waste streams. This
biogas is needed to sterilise the substrate for the mushrooms. Cattle
and chickens produce a lot of manure, which can be channelled into
a digester. This eliminates the need to cut firewood. The advantage
is a system that generates both revenues and jobs and converts a
problem into an opportunity.
A pilot project managed by Margaret Tagwira which works with AIDS
orphans in Zimbabwe has been started. Oyster mushrooms grown on
the water hyacinth substrate ensures good nutrition for the orphans
and also strengthens their immune systems. Africa University, with
the financial support of ZERI and other foundations carries out
mushroom research in the hope of possibly finding the solution to
one of our times greatest puzzles: AIDS. Additionally, instead of
depending on imported mushrooms from South Africa, Zimbabwe can
generate income and jobs from a renewable resource currently considered
a threat.
Social and Economic Implications
In general, 60 - 80% of the cost of mushroom farming relates to
the preparation of the substrate and the energy needed to treat
it. In the case of water hyacinth, the raw material is free for
mushroom cultivation, and the energy cost can be limited to the
purchase of a digester and the use of free materials. This means
that the process will require limited amounts of capital. An individual
farmer would have to invest no more than US $500 to start up an
operation and the first mushroom harvest can be sold as early as
one month after the harvesting of water hyacinth. Digesters for
individual unit, designed by the ZERI Expert professor George Chan
cost no more than US $20. A large professional and industrial unit
with a 10-20 cubic meter digester, costing US $4000 made from reinforced
cement, could achieve payback within 3 years. Therefore, the program
is suitable for a complementary micro-financing scheme or small-scale
investments.
Additional uses for water hyacinth include:
feed supplement for livestock
for raising earthworms that constitute an excellent chicken feed
for paper production
for biogas and electricity generation, creating less dependence
on wood fuel and arresting desertification"

--
lfl@intrex.net
http://market-farming.com






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