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Re: [SANET-MG] Putting the carbon back: Black is the new green
Hi Bob, Karl, Heide and John,
>>> When you add carbon in any form to the soil, add water and mix
>>> it up with cultivation, the carbon quickly converts to CO2 and
>>> evaporates back into the atmosphere. Untilled sod or forest
>>> can store a lot of carbon when undisturbed. All cultivated
>>> soils attain a natural carbon equlibrium beyond which adding
>>> more will have only a temporary benifit.
I don't think this is completely true in the case of pyrolyzed organic
matter. Heat can change the molecular structure of carbon so that it
is less biodegradable.
>> I've never seen charcoal degraded, but would love to see the
>> research to show that it actually does degrade. Charring is a
>> preservation method for untreated wood coming contact with soil.
>> I still see the charcoal on perfectly preserved tree stumps that
>> burned decades ago.
> Exactly, I use the method of charring fence stakes myself to
> preserve them and that in itself makes me very suspicious of
> those that say that it is a fertilizer or that it can help
> restore degraded soils.
I think we need to keep an open mind. Pyrolyzed OM is not necessarily
pure charcoal. I was hunting around on the web about this and found a
paper that provide background on value as soil additives of
incompletely pyrolyzed OM.
>>>> This is some relevance to the Cornell/Ithaca community near
>>>> my farm because Cornell scientists have weighed in on the
>>>> question. Johannes Lehman has said: "This is the only way to
>>>> make a fuel that is actually carbon negative"
Eprida's (and I guess Lehman's) claim (if I understand them correctly)
that one can obtain both net carbon sequestration and hydrogen, from
the same piece of biomass isn't credible. It just doesn't make sense
stoichiometrically. Photosynthesis takes hydrogen that has been split
from water using light energy, and combines it with carbon dioxide to
make sugar (and cellulose, etc). Now, when you take that sugar apart
(thermally or otherwise) you can get hydrogen and carbon dioxide OR you
can get water and carbon. But you can't get both reduced carbon and
hydrogen, there just are not enough reducing equivalents.
That doesn't mean that they can't make a business out of selling both
hydrogen and soil amendments derived from biomass, it just means that
biomass *energy* is a zero-sum game in terms of carbon sequestration.
Of course, you could pyrolyze OM and plow it into the soil, but that
reduced carbon is had at the expense of hydrogen you could otherwise
Maybe I am really missing something here. But if so, could someone
please explain Eprida's stoichiometry?
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