making biochar

As carbon sequestration goes, charcoal-making has extraordinary potential. Last year we had the good fortune to spend a day learning to make charcoal with a local historian and tried out the basics of this ancient practice. From Terra-preta in the Amazonian rainforests, stone kilns in Japan (and all over these islands, which our friend has written a book about), to colliers making clamps in the woods of Britain, it is the foundation of rich culture and the rich soil that supports it.

wood burning to charcoal in a biochar kiln

To store carbon in the soil and support the microbiome, while absorbing water events and releasing it slowly, well. It solves a host of our current problems.

wood burning in a biochar kiln

We inoculated our little pail of charcoal into biochar by layering it in the deep litter of our chicken run to absorb nitrogen and earthworm castings, then feeding the enriched soil to the trees and gardens. We could make charcoal on a micro scale in our chiminea or wood stove, and we’re looking at the piles of prunings that we intended to have chipped and considering whether to direct some of it to this simple kiln that the historian makes. Amazing.

charcoal soaking in a biochar kiln

Yesterday as I broad-forked a bed in the new potager, I turned up some of the biochar, which must’ve been harvested with compost out of the chicken run when I sheet-mulched the bed a few months ago. It’s a pleasure to see it and know it has begun its restorative work, and may well continue to benefit this soil for centuries.