Where there isn't smoke ...

There's biochar! I've written about biochar in these pages before. Techniques and understandings evolve, and there's always more to share a little way down the road.

Years of pit burns and my neighbor Kathy's wood stove have supplied me with adequate charcoal to this point. As I expand my composting operations and refine compositions, I return to biochar as an important amendment - particularly in South Sound, where we are spoiled for biomass.

Any organic material can be made into biochar, given proper duration and temperature of pyrolysis, which is defined by biochar proponents Regeneration International as "a thermal decomposition of biomass in an oxygen-limited environment." Diversity of acceptable feedstocks has been proven by scientists and methodical practitioners all over the world.

Like compost, biochar is partially concerned with repurposing surplus materials. Too much manure to use before it rots and pollutes groundwater? Truckloads of poultry litter? Biochar production or composting could turn that waste into an asset.

Although biochar is best designed for a purpose, e.g., soil enrichment or pollutant adsorption, most of us will be making it out of whatever's around, often to make that mess go away. I trimmed a lot of centenarian maples of their branches below 16 feet, and suddenly had a lot of wood blocking paths.

As with any firewood, those limbs should be dried before processing into biochar. Before I can stack them in burn pits, the old stuff has to be cleared out, and I'm ready to up my char tech to produce the best I can for my biodiverse compost.

Burn pits can't throttle the oxygen or burn temperature. The resulting char is of varying quality or incompletely burned. Careful pyrolysis needs dried feedstock, tight oxygen throttling, and recombustion of volatile gases; ideally the stinky burn pit fumigating hundreds of people, as I've seen in Gorst during the shift change, could be a thing of the past.

Huge plants incinerating such material to generate electricity are a whole 'nother can of worms. Even the impressive machines of the United Kingdom's Exeter Charcoal are beyond most of our reaches, or needs.

I need only weld some salvaged sheet metal and stock pieces into a Ring of Fire kiln that will improve my output until I can find time to build CarbonZero's small-scale biochar kiln, which produces the finest quality biochar for soil amendment from a masonry-dense design that keeps temperatures in an ideal range.

"Precise, low-temperature pyrolysis retains the more delicate, negatively charged OH (hydroxyl group), COOH (carboxyl group) and HO (also hydroxyl) groups on the carbon backbone," the Swiss company explains. Sounds legit!

I was happy to find that Wilson Biochar (wilsonbiochar.com) - another fine outfit that has done a lot of good work producing kilns, teaching and distributing plans - is giving away some of the blueprints and manuals it usually sells. They company sold out of the Ring of Fire kilns it fabricates, but we can still do it ourselves. Maybe I can beat the burn ban!

P.S.: Free giant sequoias and coastal redwoods up to 6-feet tall will be available again in fall from Michigan's Archangel Ancient Tree Archive, via Dave Pearsall in McCleary. Email me to get on the list, pickups will receive preference.

■ Alex Féthière has lived on Harstine Island long enough to forget New York City, where he built community gardens and double-dug his suburban sod into a victory garden. He can be reached at [email protected].