To: "permaculture" <permaculture@lists.ibiblio.org>
Subject: Re: [permaculture] Biochar
Date: Fri, 18 Nov 2011 19:31:41 -0000
I am well aware that it is impossible to make somebody change his or her
mind. Especially in matters like religion. Dogma rules no matter what the
evidense or what common sense has to say.
I am well aware of the stability of charcoal but that it serves as living
space for microbes is pure nonsense. You can't have it both ways. If it were
good for microbes it would not be stable. It is one or the other and you
really can't keep your cabbage and eat it at the same time.
And I also can't see it as a sink for soil minerals. As a slow sink for
mercury yes and organic pesticide molecules probably.
john
A piece of charcoal in the soil is carbon that is sequestered for hundreds
or thousands of years. To give you an idea how stable charcoal is, ponder
that carbon dating techniques of archeology are based on measuring carbon
isotopes in charcoal from ancient sites.
More importantly, think of each piece of biochar as a giant apartment house
for soil microbes., A place to sleep, eat, rest, procreate and evade large
predators. Each piece of biochar is a great place for cation exchange
activitity and many soil nutrients are adfixed to the biochar. They are a
sink for soil nutrients. Each apartment house is occupied by an endless
stream of tenants for hundreds or thousands of years.
They also hold moisture and add texture and porosity to soil.
this all adds up to increased soil life, increased crop yields, increased
biomass.
All in all, a pretty good thing to have in your soil. Multiply the
beneficial affect on arable soils worldwide and we have one of the
techniques that can help us build an exhuberant biosphere.
Only one technique out of many, but let's use it where appropriate.
I highly recommend research, experimentation and an open mind.
Michael pilarski
--- On Wed, 11/16/11, Toby Hemenway <toby@patternliteracy.com> wrote:
From: Toby Hemenway <toby@patternliteracy.com>
Subject: Re: [permaculture] Biochar is part of a LOCAL solution
To: "permaculture" <permaculture@lists.ibiblio.org>
Date: Wednesday, November 16, 2011, 8:50 PM
On Nov 16, 2011, at 3:33 PM, John D'hondt wrote:
I like this but still think that charcoal burning is detrimental if we
want
to stop climate change. We produce 20 times more CO2 while making charcoal
than we ever sequester whatever system we use.
I was just at a biochar workshop this weekend and the numbers given were
that the method we used can sequester 40% of the carbon in a given piece of
wood, and that's more than if microbes ate it, and far better than the "20x"
that you state. Does your number come from an actual calculation? The
numbers I've seen suggest that a clean pyrolysis is carbon neutral or even
negative by weight, since putting pure carbon in the soil means that nearly
3 times that weight (the weight of one carbon plus two oxygens) is kept out
of the atmosphere. (that strikes me as a funny way to calculate it, but
that's how they do it for CO2)
I think the jury is still out on biochar in temperate climates, but
replacing inefficient open fires or wood stoves with biochar pyrolysis makes
a huge amount of sense, since you get a much cleaner burn (reduced
pollution), more efficient generation of heat for cooking, and a useable
product in the charcoal, instead of ash. So for cultures that rely on wood,
it's very smart.