Science Forums 2

[maikeru]

I think that the fact that charcoal is so stable makes it a good option for current farming or gardening methods that include tillage. The charcoal may capture gases released from the soil if organic material is aerobically or anaerobically degraded into methane, carbon dioxide, or various nitrogenous gases.

I also think Dr. Hodges has a point about microbial population shock due to low N levels, but microbes can repopulate rapidly given the right conditions or enough time. In the case of terra preta, it seems that soil microbes and fungi thrive due to numerous reasons. But there is a reason why terra preta was amended with kitchen waste, bones, manure, etc. Charcoal alone doesn't do much, as I've noticed from experimenting with my indoor herb garden. Seeds don't seem to like to germinate in a soil too high in charcoal content (I tried some basil, thyme, and marjoram in a 70 or 80% powdered charcoal and potting soil mix, and I got a few weak seedlings which died a few days later; quite the contrast to my other ones growing vigorously in 20-40% charcoal).

BTW, I want to let you guys know that you've made a terra-preta gardener out of me over the last couple months as I've lurked on this forum and in particular this thread. Black is the new green.