[Terrapreta] reduction by fire vs. water

[dyarrow at nycap.rr.com]

i'm at an organic raspberry farm in concord, MA.  when i drove in, i 
saw a huge pile of very dark -- almost black -- organic matter, and 
thought someone had made a giant heap of charcoal -- easily over 100 
tons.  but it proved to be dredgings from a boggy pond.  the organic 
matter on the pond bottom decomposes in an oxygen-deprived 
environment, similar to a pyrolysis chamber, and thus the material is 
reduced instead of oxidized.  hence the carbon-black residue.

i have little notion how this water-formed, reduced carbon compares 
physically, chemically and culturally with fire-produced char, but it 
definitely makes a significant contribution to soil organic matter 
content and thus fertility and productivity.  however, i would expect 
this dark pond-bottom-muck has a much different microbial community 
due to its watery origin and formation.  anaerobic fermentation and 
digestion by bacteria does not seem at all like the fiery degradation 
of pyrolysis, and would not leave behind the same kinds of volatile 
organic compounds as nutrient sources for soil organisms.  yet, nature 
is forgiving, since we know muckland from drained swamps is highly 
productive agricultural soil.  however, i believe mucklands degrade 
rapidly with intensive use, since carbon and other organic residues 
are rapidly oxidized and volatilized, resulting in rapid loss of that 
rich, black topsoil.

by contrast, degradation of organic matter by fire seems to result in 
a carbon residue that is "recalitrant" and resists all sorts of normal 
chemical oxidation and biological digestion.

david

----- Original Message -----
From: Kevin Chisholm <kchisholm at ca.inter.net>
Date: Thursday, November 22, 2007 10:14 am
Subject: Re: [Terrapreta] TP theft.
To: lou gold <lou.gold at gmail.com>
> 1: There is a pond in front of where I live. In the Summer, pond 
weed 
> drifts into a cove, and decomposes anaerobically to give a black 
goop on 
> the bottom When stirred up, the water turns black. The pond weed is 
not 
> consumed totally by pond life forms, but rather, a black material is 
> left behind. It could be "black carbon."
> 
> 2: In Northern Canada, there are millions of hectares of Humified 
Peat, 
> where  the  the original sedges and mosses  are decomposed to the 
> point that little or none of their original plant structure  
remains. 
> What does remain is a "black carbon-like" material.
> 
> 3: Many Farmers drain swampy areas, and start a Market Gardening 
> Operation, because  vegetables grow so very well in the "black 
earth" 
> that they uncover. Do a Google Search on "Terre Noire", "Terre 
> Noire Canada", and "Black Earth". See also
> > http://www.blackearth.org/History/History.html
> In speaking to a Member of the Historical Society, the Community of 
> Black Earth seems to be built on a eutrophied lake. However, there 
was 
> indeed an Indian Community well established there, long before the 
White 
> Settlers came. The water table is very close to the surface, and 
> buildings of any size require pilings for foundation support.