Biochar Production
Biochar is a carbon-rich substance that can rejuvenate soil. It is produced by burning biomass in low-oxygen conditions. Biochar can act like a sponge and serve as a habitat for many beneficial soil microorganisms that are known to promote soil and plant health.
On April 10, 2024, US-LT RCD staff performed their first day of biochar production. Weeks prior to the production day, US-LT RCD staff members gathered downed woody material that had accumulated throughout the property and consolidated that material into piles to cure. Once the wood had cured, it was then placed in one larger pile inside of our Wilson Ring of Fire Biochar Kiln. The feedstock pile was composed of 100% coast live oak (Quercus agrifolia) from a large tree that had fallen over in the historic storms of 2023 and had blocked an access road at the Conservancy. The feedstock volume was approximately three cubic yards of material.
Ignitions took place at 10:30am and ended at 11:45am. The kiln itself was not overtopped with feedstock, and ignitions went smoothly and safely. There was very little smoke from the ignitions due to the counter-flow combustion design of the Biochar Kiln. The instruction manual from the Ring of Fire Biochar Kiln describes counterflow combustion as “… [when] all the air for combustion comes from the top. This control of the air flow is what allows the kiln to preserve char as it is made in the kiln. Each time the user adds new material, the air comes down from the top to feed the flame. Char beneath the burning material is protected from the air, because the flame uses up all of the available air.”
Our staff members estimated that the kiln produced roughly 25 gallons of biochar. The biochar production day was fun and informative, with many lessons learned on fuels management and climate strategies in an agricultural setting. For example, our staff found that pieces of feedstock larger than 4 inches in diameter took longer to process into more uniform sized pieces of biochar, and consequently were less than ideal for use in our kiln. A solution devised by our staff to mitigate this sizing issue was to utilize log splitting to bring feedstock diameters down to more manageable sizes. We’re looking forward to conducting another biochar production day and hope to involve more members of our growing regenerative agriculture community.
