[Terrapreta] Charcoal in soil

[Nikolaus Foidl]

Dear List!

I have done in the last 2 months several trials to find out the effect of
charcoal buried some 18 years ago in our fields.
The forests where chained down ( cleared) and then with huge caterpillars
heaped up in charcoal stripes of 10 to 12 meter width and some 2.5 to 5 km
lenght(depending on the field size).
 In 180 meter wide fields there are 2 stripes with some 30 meter distance
from the surrounding living fences and some 60 meter distance  between them(
mid to mid)
In 240 meter fields there are 3 to 4 charring stripes.

In Soy , Maize and Sunflower when you measure exactly every 0.5 meter the
productivity perpendicular to the direction of the char stripes you find an
up to 250% increase of productivity in Maize, up to 30 % rise in
productivity in Soy and up to 47 % rise in productivity in Sunflower exactly
on top of the charring stripes.
The rare thing is this elevated productivity stripe is not as suspected as
well 10 to 12 meter wide its only 3 to 4 meter wide.
After burning all the trees including there earth laden roots the remaining
ash and some remaining char was distributed over the field with
caterpillars.
So it can not be the ashes. My suspicion is, and I see similar suspicions
being discussed by Stephen from Australia, that the heat and the organic
vapors and the coal together with the soil particles formed some organo
mineral which keeps cationic/ anionic interchange capacity at high levels
even after 18 years of continuous cropping without fertilizer.
Looking at the carbon content in the Charcoal stripes turns out to be some 3
tons per ha in the first 25 cm.
 If somebody wants to elaborate on this observations, welcome!

Best regards Nikolaus