[Terrapreta] Charcoal mix continued

[Sean K. Barry]

Hi Michael,

As I understand the study of  the Amazon Terra Preta sites, the charcoal found in the soils today is very old (2500-4500 years old, document by carbon dating).  It is also at 30% now in some places and was probably left that way when it stopped being used.  It was also used at lower densities in other areas and maybe was used in the 30% areas when the densities were lower and prior to that time usage stopped.  It has been found very deep (like 5 feet) and always in layers.  Some sites appear to have had charcoal continuously incorporated into them over perhaps centuries.  So, I think your theory about small applications over time is cirrect and supported by evidence in the Amazon.

The pure carbon element of the charcoal (approx 93% pure carbon) is highly resilient in soil.  It does not dissolve, does not wash away, does not gas off into the atmosphere, does not get decomposed by soil microbes, nor does it get taken up into roots and used by plants.  However, the volatile matter in charcoal (sometimes "bio-oils", "wood tars", "wood vinegar", "tars", liquid smoke", etc) is decomposed by soil microbes.  But the bulk of the charcoal (the carbon) stays for centuries with little discernable loss.

SKB
  ----- Original Message ----- 
  From: Michael N Trevor<mailto:mtrevor at ntamar.net> 
  To: terrapreta at bioenergylists.org<mailto:terrapreta at bioenergylists.org> 
  Sent: Tuesday, April 17, 2007 4:20 PM
  Subject: [Terrapreta] Charcoal mix continued


  To all those who tossed information into the ring thank you very much.
  Since I am also currently working with pots and home consumption
  items like basil, green onions, red peppers etc I will go straight to the
  about 20%, one pot at a time first  It will be a considerable time before my
  TLUD stove(s) with be fully functional on a regular basis to produce enough
  to turn into
  the gardin.

  One thought, at the risk of repeating what may have been said before, if
  Amazonian terra preta
  soils are about 30% charcoal, what was the percentage when they were taken
  out of useage?
  Does the percentage of charcoal reamin fairly constant once incorporated
  into the soil?
  Also since these soils were apparently developed over hundreds and even
  thousands of years
  even minute amounts must be beneficial. It would seem likely that producing
  and incorporating charcoal
  in to the soil would have occured in rather small sequential doses over
  generations. Massive charcoal generation
  to jump to a high percentage would seem unlikely unless it was carried out
  small plot by small plot.

  Sincerly yours,

  Michael N Trevor
  Enemanit , Majuro
  Marshall Islands

  . .


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