[Stoves] Biochar Projects for Science Students

[Andrew C. Parker]

Crispin and All,

In regards to "accidental" terra preta, I am including a post I made to  
wattsupwithat.com last January:

"Many years ago, I read a book on swithen agriculture in the upper amazon  
basin and the eastern woodlands of the US. The main point of the book was  
that these ecosystems supported many more times the current populations  
before european agricultural and land tenure patterns were established.  
The vast majority of land cleared in the late 1700′s and early 1800′s in  
the eastern woodlands has now reverted back to forest. The thin forest  
soils were quickly depleted after clearing and burning, forcing families  
to move West for better opportunities.

Swithen agriculture used a strictly managed rotation system that maximized  
the resources of the forest ecosystem, giving the native populations a  
sustained abundance of agricultural goods, forest products and wild game.  
(It is theorised that the devastating epidemics that followed the first  
european explorers left remaining populations unable to maintain forest  
management, which may explain why Hernando De Soto’s descriptions of the  
american south differed substantially from what later explorers and  
settlers found.)

I have not read much of the terra preta literature but the description of  
the charcoal being found in thin layers would seem to support the idea  
that the native inhabitants used a rotating swithen agriculture that could  
still be found in some areas of the amazon basin thirty years ago. Nothing  
magic or mysterious.

Now, I wonder if terra preta soils can be found in the eastern US?"

I still wonder about terra preta in the US.  Any soil scientists out there  
that can answer the question?


Andrew Parker



On Fri, 26 Nov 2010 08:54:16 -0700, Crispin Pemberton-Pigott  
<crispinpigott at gmail.com> wrote:


> It would be interesting to know if the terra preta soils were  
> artificially
> created or were the consequence of cyclical burning in a rotation (slash  
> and
> burn).