[Terrapreta] a braoder theory of torrefaction and TP

[Duane Pendergast]

Good thoughts there Jim, but it would likely perform similarly to  a
landfill. Those tend to generate methane which we are told is a much more
effective greenhouse gas than carbon dioxide.  Charcoal might be a good
substitute for some of the goals you mention and seemingly would avoid the
methane production.

 

Duane

 

-----Original Message-----
From: terrapreta-bounces at bioenergylists.org
[mailto:terrapreta-bounces at bioenergylists.org] On Behalf Of Jim Joyner
Sent: December 10, 2007 7:47 PM
Cc: Terrapreta preta
Subject: Re: [Terrapreta] a braoder theory of torrefaction and TP

 

You know, We've all been looking at the sexier uses of various forms of
burned wood in the top soil, but if you want a cheap way to sequester
carbon, burying sawdust or chips in the subsoil accomplishes the same thing
(burying charcoal below the topsoil makes no economic sense, serves little
or no purpose). It  works because there is little or no biological activity
in the subsoil.

I don't know how long it lasts but it gotta be at least decades. But it
might be forever. I was always involved with the farming side, not the
research, but I know of experiments that were started 25 to 30 years ago in
Missouri. They took sawdust, mixed it with subsoil and buried it as much as
six feet deep in long trenches. The purpose was to give certain deep rooted
perennials (grapes, in this case) more root room and create a moisture
reservoir. 

The moisture reservoir is a good idea for not only plants but for good water
shed. And, it buries a lot carbon waste product that doesn't need to be
processed.

There are even less invasive ways to bury woody material in the subsoil too.
For example, I subsoil my beds for annuals to about 3 feet. I balance the
subsoil by adding limestone (I built a device that subsoils and adds lime at
the same time. Not all soils need the lime) so that it will be lose not only
physically but electrically. Then, every year a crop sends a new set of
roots down and leaves them behind. The blackness of the soil gets deeper and
darker every year. The water holding capacity of the subsoil increases every
year. 

Jim

Gerald Van Koeverden wrote:



I like your idea....we 'soils peoples'  have to broaden our scope of
interest from 'biochar' to the whole range of "torrefied wood".  Let me try
to build a new 'theory."

 

Torrefaction does something to the wood so that it lasts much longer in the
soil than non-torrefied wood.  What happens in torrefaction?  "This process
removes all naturally occurring resins, sugars and oxygens while collapsing
the cells. This accomplishes two things: First, it gives the lumber a deep,
rich brown color...Second, and more importantly, it alters the wood to make
it extremely stable, moisture resistant and decay resistant."

 

This extended life effect is not just because it drives out enough moisture
to inhibit decomposing organisms, but it also provides a suitable habitat
for non-decomposing soil-dwelling organisms - not dependant on as high
moisture contents - which in turn protect their habitat from rapid
decomposition.  If these MO don't completely inhibit decomposition, they at
least have a significant effect in slowing that process down.  It is the
biological activity of these micro-organisms inhabiting the torrefied wood,
which increases the fertility of those soils and make TP's what they are.

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