Homestead mailing list

[Gene GeRue <genegerue AT ruralize.com>]

On Jan 25, 2009, at 12:03 AM, Frank Fries wrote:

> Some of the people who have done quite a bit of work on this  
> actually think
> it matters what temperature the charcoal is "cooked" to.  But again  
> nobody
> really knows.

Wikipedia has an extensive entry on terra preta here:
http://en.wikipedia.org/wiki/Terra_preta

It includes the following:
"Topoliantz and Ponge's work, summarized in a synthetic article in  
“Soil Biology & Biochemistry”[35], shows that the peregrine earthworm  
Pontoscolex corethrurus (Oligochaeta: Glossoscolecidae), widespread in  
all Amazonia and notably in clearings after burning processes thanks  
to its high tolerance of a low content of organic matter in the soil,  
has been shown to ingest pieces of charcoal and to mix them in a  
finely ground form with the mineral soil. The authors, who  
experimentally verified this process, point at this as an essential  
element in the generation of Terra preta soils, associated with  
agronomic knowledge involving layering the charcoal in thin regular  
layers favourable to its burying by Pontoscolex corethrurus. . . .

The last graph reads:
"Efforts to recreate these soils are being undertaken by companies  
such as Biochar Energy Corporation, Eprida and Best Energies .  
Research efforts are underway at Cornell University, the University of  
Georgia, Iowa State University and Geoecology Energy Organisation.  
Biochar is the main (and likely key) ingredient in the formation of  
terra preta. One focus of these researchers is the prospect that if  
biochar becomes widely used for soil improvement, it will involve  
globally significant amounts of carbon sequestration, remediating  
global warming."

While fascinating, especially regarding fertility longevity, I don't  
see a direct use by home gardeners. As we have noted before, each  
garden is unique in its many features: soil origin, moisture,  
drainage, temperature, organic content, soil community, and sun aspect  
and duration. Each gardener is thus a scientist for their individual  
plots. While there are many generalizations that are applicable to a  
broad range of soil and climate conditions, it is likely foolhardy to  
attempt to adapt this unique Amazonian condition to a North American  
garden.

Soil science is a huge subject and homesteaders can easily find books  
on the subject. Simplistically, plants cannot eat chunks of nutrients.  
These nutrients are processed by a myriad community of microscopic  
organisms whose excretions are absorbable by fine root hairs. The  
number of microorganisms in good, living garden soil is so great as to  
be incomprehensible. The population of a handful of such soil is far  
more than the human population of the largest city on earth. The  
earthworm is the giant of the soil community and of inestimable value,  
but North American soil most likely does not include the peregrine  
earthworm noted above.

Should the production of miracle charcoal become feasible we will  
expect its availability soon. We will also expect misleading claims  
and high prices.

Learn how to feed the soil community; that community will feed your  
plants and then the plants will feed you. A closed circle.

Gene GeRue
www.RURALIZE.com