Subject: cold composting
Mike writes: MN>Hi: Being aware of your wisdom from following
your posts to rec.gardens, I imagine you might be able to
provide me with some help regarding info on `cold composting'.
Well, my propaganda proceeds me or my paid supporters need a
raise. But thanks for the kind words anyway. (g)
I saw and pursued a reference to a recent Audubon
>Magazine article on an interesting gentleman who got his
county in an
>uproar by bringing in huge amounts of wood waste to his
land. He carried
>out what was referred to as `cold composting' to speed the
>the woody material (without any shredding or grinding) by
>Besides keeping the material moist, are there other tricks?
My understanding of the story was that the amounts were not
quite so "huge", like great tire stockpiles ready to be hit by
lightning, but were fairly normative mulch layers. The "huge"
terminology might really more aptly be called "out of the
ordinary". Huge, to me, implies thirty foot high stockpiles
such as one might find at a sawmill. Even then, people are
hardly in an uproar over these "huge" piles. The concern it
seems, is the fact that the material is deemed to be "waste"
and therefore subject to the NIMBY or NIMTOF (not in my term of
> My personal interest in this is not so grand as this
>I've just got whole lot of branch wood and prunings that I
>making a dent in with a 7 hp Mac chipper/shredder. I mean a
>a pile 40 feet long by 12 feet wide by 5 feet tall. It's
daunting to park
>the chipper next to it and wonder how many hundreds of hours
it will take
>to reduce it all to mulch.
Ah yes Grasshopper, Master Po said to Quai Chang Kane, when this
stockpile of brush is reduced to humus, then it is time for you
The first point is that nature does not compost; nature
mulches. We do not see piles of organic matter in nature,
aside from a few notable exceptions of mound building reptiles,
nesting birds, rhinos in dung etc.
Nature deposits organic matter down in thin layers where it is
"cold" composted, if ambient temperatures can be called
"cold". Years ago, it was called "sheet" composting, but one
rarely sees such a term anymore.
But the fact of the matter is that it is the mesophiles,
organisms which function from 40F to 120F that are the true
decomposers. The thermophiles, those operating over 120F up to
the pasteurization temperature of 147F, are lazy sons of guns
who thrive on the heat of their cooler brothers, but do little
to aid the decomposition process themselves.
When a carbon compound is broken biologically, one mole of CO2
and one mole of heat is released. In layers, this heat is
dissipated through convection. In piles, this heat is retained
due to the self-insulating properties of the composting mass.
It seems that the best temperatures for decomposing carbon,
which wood mulch represents, are in the 110F-120F range. Much
of this carbon is bound by cellulose which is highly resistant
to decay. The best means of attacking cellulose, aside from
hiring termites, is to enlist the aid of fungi.
This is what termites actually do in their gut, and is what the
gentleman referenced in the Audubon report is also doing. I
would suggest adding around 10% old compost to the wood mulch to
assist the inoculation process so that the decomposition can
proceed in earnest. Keeping it moist as you note is also
The real question is whether or not the organic matter is being
processed for a beneficial use or if it is being "disposed on
land". If the person is simply stockpiling in order to garner
"waste tipping fees" with no plan for the ultimate beneficial
use of the mulch or resultant decomposed organic matter, then I
would challenge the plan, just as I would stockpiling tires.
The greater crime is sending organic matter to the landfill
where it serves no beneficial use at all. Even worse, it
decomposes into explosive methane, merges with toxic leachate,
shrinks the landfill causing cracking in the clay cap, and
benefits no soils at all. So even a farmer making an extra
buck spreading wood mulch is better than the landfill
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