Bruce Fields (Chicago) recommended to visit the following website :
Hypography is a site on “Science for everyone”, where I found :
Terra Preta Discussions related to Terra Preta
Furthermore, Bruce FIELDS recommended to have a look at Phillip SMALL’s site :
where I found a contribution on Terra Preta :
“Friday, May 23, 2008
Note: Bio-char, agrichar, and charcoal are interchangeable terms when it comes to the intentional use of charcoal in the garden.
The argument for encouraging biochar use as a ubiquitous household practice is compelling: Improved garden soil will increase food production where it has the most impact on energy demand. Implementing charcoal manufacture at a household level draws in a supply of yard prunings and workbench scraps that otherwise would be lost to non-charcoal alternatives.
Unfortunately, finding even the most basic information on how to implement biochar use as a personal sustainability practice is discouragingly time consuming. In response I have started up a FAQ, a collaborative wiki, building on the efforts of the TP enthusiast community (1, 2, 3). Maybe you, the concerned gardening public, can help us thresh out the most important questions that need asking.
I am very grateful to Bruce FIELDS for his good advice. Phillip SMALL’s site is a splendid one for people interested in soils. I put a link to his site on my Blogroll.