minerals, rabbits, etc.

Jack Rowe jackrowe at compuserve.com
Wed Sep 17 23:27:38 EDT 1997


Good reminder about using natural local cycles for minerals whenever
possible, Gene. Hmmm... 25 years of being made fun of for being a flaky
organic gardener, and now it's coming from both directions... I’m getting
too old, and I’m not old yet.

Problem in many areas is that a couple-hundred years of farming (erosion
and exporting produce) and ranching (erosion and cow bones shipped far
away) have depleted Phosphorous from many soils, and the roots of trees
don't find P if it isn't down there (in Texas and many parts of the
Southwestern US, and most of Australia, roots don't have to reach DOWN to
find subsoil -- it's right there on the surface). Functional P cycling also
requires scrupulous returning of manures, bones, etc. from all the food
taken off a farm. In our present systems, nobody is bringing their manure
back to the farmer (most are hiding it from their eyes and minds, flushing
it away, carried by a sizable amount of drinking water to
they-know-not-exactly-where). 

Dynamic accumulators are great for nutrient cycling (lacking lists, a
general rule is that a plant which is high in some nutrient is an
accumulator for that nutrient, so foods’ nutritional analyses can point to
accumulators -- I’ll get my list into binary form and share it, let’s all
do that). Dynamic accumulators can take up even poorly-available minerals
present in soil or subsoil, BUT, they can’t SYNTHESIZE minerals -- they
just grab what’s there. With the exception of Nitrogen and Carbon
(available atmospherically), if nutrients aren’t in the soil, they can’t be
recycled. Trees will likely work pretty quickly if P, K, etc. are present
in subsoils at some practical depth, this just isn’t always the case. So we
are going at some point to have to rebuild many depleted soils with
minerals from somewhere, THEN start recycling everything. Phosphorous IS in
fact strip-mined, you betcha, then used on farms, then eaten, then shat and
flushed into waterways, then drunk a few times more, then shipped out to
sea. Lotta room for improvement there. 

Re: Constructed wetland blackwater systems... these are being used by some
fairly big cities now, including Beaumont, TX, which has built a popular
municipal park around their system. These systems seem to me inferior to
simple composting in that they are built to diffuse the energy in the
manure and urine, most of this being metabolized by bacteria in the gravel
bed, and a smaller amount ending up in vegetation planted over the canals.
Great for municipalities, perhaps less efficient at nutrient reclamation
for homesteads than composting. Here in TX, licensing and engineering costs
make the otherwise-cheap systems pretty expensive to install.

Re: Rabbits and their manure... rabbits are coprophagic, a euphemism
referring to their nutritional habit of eating their manure on it’s first
trip out of their bodies. They eat quite a bit of roughage when summer’s
heat slows availability of leafy greens. Commercial feeds are rich enough
to account for this discrepancy. A friend of mine starved his rabbits by
growing them on hardware cloth above the ground and stealing their manure
while only feeding them not-particularly-rich natural foods. If they’re on
the ground in tractors, this wouldn’t be a problem.



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