[Terrapreta] Charcoal--- what sort?

[rukurt at westnet.com.au]

Hi folkes,

I keep seeing all this stuff about making charcoal from biomass and 
sticking it in the soil and getting increased production as a result.

But will we?

 From what I've read, the charcoal in TP is hardwood charcoal. 
Micrographs of even the finely divided lumps shows the typical hardwood 
structure maintained in the charcoal. We believe that this structure is 
responsible for the porosity of the charcoal and it's special properties.
Will softwood charcoal have a similar structure? Not necessarily. 
Hardwood has a lot of "vesicles" which are the main contributing factor. 
Softwood is not structured the same way and might not be half as 
effective. Until we do work with sopftwood charcoal, we won't really know.
Similarly, what is the fine structure of nutshells? Much porosity in 
charcoal made from them? I know they tend to make activated charcoal 
from nutshewlls, but the porosity is created in them with heat and steam 
and it is said to not be as good as  hardwood charcoal for TP.
What about charcoal from grass? does it have structure, Dr Karve might 
be able to elucidate on this, his daughters charcoal retort system was 
made to handle sugar cane trash.
What about charcoal from soft green weeds?
The charcoal I made from shreeded palm fronds did not strike me as 
particularly useful for TP purposes, but I don't have microscopes 
available for a closer look.

Experience, once gained, may show us that only hardwood charcoal is 
really suitable, then again, it might give us the green light for anything.
 Additionally, we have little real kn owledge of the role of pottery 
shards in the process.

Kurt