SuperDirtt for Hawaii?

[JWFITZ]

And in terms of your second post, yes. The char will soak up anything it gets a hold of. As far as I can see its action as a buffer is the primary one.

[MarkP]

More random thoughts:

Even if it does nothing else, charcoal would be similar to pearlite in lightening the soil in that it would be porous, benign, and would not rot.

Both composting and charcoal production start with the same feedstock. During composting, most of the carbon turns into something else, with much of it being CO2 and methane. Knowing nothing about the actual chemical processes but using the same level of seat of the pants reasoning applied so commonly on the internet, simply charring the feedstock and letting the CO, CO2, and methane leak into the atmosphere would be similar to composting in terms of how much greenhouse gas is produced. If correct, that is a bit of an eye-opener for me. A compost heap is viewed as totally benign or actually good for the environment, while a smothered fire is viewed as really bad. What am I missing? Smoky fires produce particulates. They are definitely bad. So a compost heap is on a par with a clean burning fire?

I read somewhere about earthworms helping to chew up the charcoal and mix it in.

[JWFITZ]

It is a very very interesting take on things, and one that requires a lot of practical study. One can keep the biochar process pretty clean really in terms of emissions. There is definitely a place for both charing and composting in soil improvement. Neither are wholly benign, but in conjunction may well be quite so and more than is thought.

[MarkP]

Found this straightforward description of how one guy makes charcoal. Basically similar to what we've discussed so far but more refined maybe. Sounds like a high temperature process though. Is there any definition of what is high temperature vs low?

http://www.twinoaksforge.com/BLADSMITHIN...ARCOAL.htm

[JWFITZ]

I'll post a chart that explains it all. It's a function of temperature and moisture content. High temperature is good for fuel production--and methane and the like. This is used for gasification as well. Low temperature and high moisture content(over 20 percent) produces mostly hydrogen and carbon monoxide.