[Terrapreta] Terra preta 101

[code suidae]

On 9/20/07, Jon C. Frank <jon.frank at aglabs.com> wrote:
> How to incorporate it into soil
> Seems it's best not to disturb soil to much. The "wee beasties" don't like
> there homes ripped up.
>
> On row crops I would suggest working charcoal into the soil.  Carbon tends
> to rise in soils.  Working the soil also adds oxygen which benefites aerobic
> bacteria.

My major project for this weekend is to incorporate compost into my
loess soil garden. I have char that I'd like to include as well. My
intention is to dig the soil to about 18 inches and then mix in an
equal quantity of compost. The plot is divided into thirds of about 20
square feet each. I'd like to keep one char-free as a control, and add
char to the others at varying rates (I'm thinking 5 and 10 t/a).

Should I mix in the char to the full 18 inches, to a lower depth, or
just spread it on top?

The char is in large chunks (like 4x4 inches), how finely should I
divide it? Crush to marble size, grind to coarse sand size, or ball
mill to powder?

Most of the trials I've seen use finely powdered char, would larger
chunks reduce performance?

Thanks
Dave K
-- 
"Our ignorance is not so vast as our failure to use what we know." -
M. King Hubbert