[Terrapreta] Early Terra Preta Production

[dyarrow at nycap.rr.com]

thanks, robert, for keeping this important discussion alive.  the 
relax assumption is charcoal = wood.  but we need a broader 
perspective of likely feedstocks for char production.

35 years ago, living in new mexico, i learned the navajo method to 
make pottery by firing the ots in a pit filled with dried cow pies -- 
areadily available and abundant resource in that arid climate.  worked 
wonderful.  it was common knowledge how to close up the pit, and 
create a reducing fire that yielded beautiful black pottery.  of 
course, before the spaniards appeared 500 years go, there were no cows 
in the southwest.

cornstalks make excellent feedstock to make biochar -- or just for 
cooking in the kitchen.  especially tropical strains of corn, which 
often grow 12 to 15 feet tall.  i grew some guatamalan corn in my 
backyard garden in upstate NY a few years ago in a classic three 
sisters garden, and was startled how high the stalks grew.  
unfortunately, before they tassled, the frost killed them.

however, my own conclusion is indigenous amazonians used more than 
crop residues.  fertile soil in a tropical climate erupts with an 
abundant diversity of green growth.  maintaining cropland means steady 
efforts to remove weeds, bushes and saplings sprouting from the soil.  
i doubt the indigenous growers -- mostly the women -- practiced the 
kind of clean cultivation of modern farmers, where the soil is swept 
bare except for the designated crop.  indigenous weed removal would 
have been more selective and thoughtful.

i would guess that the average amazon field produced far more weed 
biomass each year than crop residue.  and most of this would have been 
non-woody weeds that will crumble easily into dust once converted to 
char in a pottery kiln.  how can forensic soil analysis identify this 
non-woody biochar after 300+ years of residence in the soil?

david yarrow

----- Original Message -----
From: Robert Klein <arclein at yahoo.com>
Date: Tuesday, January 8, 2008 4:05 pm
Subject: [Terrapreta] Early Terra Preta Production
To: terra pretta group <terrapreta at bioenergylists.org>

> Hi All
>   
> Early Terra Preta Production
> 
> As my long time blog readers know, terra preta is a man made soil 
located
> in the Amazon by the Indians up to the time of the conquest for at
> least a thousand years. Besides the substantial 15% content of 
> powderedcharcoal we have an additional persuasive content of 
> apparent broken pottery shards throughout.
> 
> The Indians were able to produce
> powdered charcoal while consuming a lot of low grade pottery in the
> process. This is many tons of charcoal per acre. The manufactured 
soil
> retains fertility without significant assistance in an environment 
> wereits only competitor is low productivity slash and burn. High 
> densitysettlement resulted and was almost certainly responsible 
> for the
> legends of El Dorado. The Spaniards were about a generation too late
> and the knowledge was lost.]
> 
> Reconstructing the production protocol was tricky but is is really 
> very simple.