Charcoal and Wood Ash
Wood Ash Permaculture
I already talked here about using wood ash as organic fertilizer so what I’ll talk about here is how making charcoal fits into a permaculture arrangement. On the one hand, I don’t really like burning and filling the air with smoke. On the other, what basically harmless and natural wood fire smoke I put into the air is nothing compared with the industrial waste and noxious chemicals that big corporations pollute out environment with every minute of every day.
Horrid Big-Ass Corporations and the greedy swine people who profit from them do NOT put even nearly enough back for what they take out and befoul. We people must someday retake our world back from those who have stolen it.
But that’s not quite what we’re talking about today. I’m discussing burning some otherwise useless wood like branches pruned from fruit trees, to make something useful like charcoal, and then to take the rest to add fertilizer back into soil.
Pictured right is an over where some charcoal was baked and then removed.
A typical type charcoal burning mound is about meter or two in diameter at the base and about 1 to 1.5 m high, approximately a flattened hemisphere. A few air inlets are made at the base and an opening at the top about 20 cm in diameter allows exit of smoke during burning. All openings must be sealed with earth when burning is complete and the mound is allowed to cool.
A space about 3 meters in diameter is cleared, leveled and compacted. It should be well drained. A post about 1 meter tall is sometimes erected at the proposed center of the pile of wood to assist in stacking the wood, to give stability to the pile and to provide a support for the operator when the pile is being covered with earth and the top smoke hole made, and later when the pile is lit. The pole is usually removed before lighting to provide a central opening through the pile.
A grid of crossed small logs about 10 cm diameter is first laid on the ground radially to form a circle about 4 meters in diameter. The wood to be made into carbon, is then packed densely on this platform whose purpose is to allow the fire and hot gas to circulate properly. The longer pieces of wood are stacked vertically leaning against the center pole. The shorter logs are placed vertically towards the periphery so as to develop a more or less regular profile. Gaps between logs are packed with small wood to make the pile as dense as possible. The surface of the pile is packed out with small fuelwood as necessary, to give as even a profile as possible, and provide good support to the earth covering. It is good practice to allow the piled wood to dry out for as long as possible and to cover the pile during dry weather. To seal the pile, first straw, leaves, coarse grass, etc., are spread over the pile and then earth or sand spread over this layer. A sandy soil or loam which has low shrinkage on drying is preferable.
Charcoal fines can be mixed with the earth. The thickness of the covering will vary depending on the smoothness of the wood pile, but around 10-20 cm is typical. The coating should be checked to seal all cracks and to check that the air holes at the base of the mound remain open.