Brian Smallshaw has been experimenting with charcoal and biochar since 2005, after visiting a traditional charcoal kiln in Iwate prefecture in Japan. On his property on Saltspring Island he has constructed several kilns based on the design of traditional Japanese kilns, and using a wide variety of material for feedstock; including wood (arbutus, conifers, fruit woods), coppiced willow, blackberry, Scotch broom, and scrap lumber. He makes charcoal for cooking, for artists, and for use as biochar. In 2017, he researched and contributed to a booklet published on the traditional Japanese Canadian charcoal kilns of the Southern Gulf Islands. Most recently he has constructed several portable cavity kilns to facilitate the making of biochar from woody waste material from homes, gardens, farms and woodlots.
The term ‘biochar’, referring to charcoal used as a soil amendment, is relatively new, but the concept is ancient, going back at least half a millennium and likely further. Long ago farmers learned that adding charcoal to their soils improved soil fertility, while improving its ability to retain moisture.
There is much that remains to be learned about how biochar works, but charcoal in the soil seems to provide a habitat for beneficial soil bacteria and fungi in its multitude of microscopic cavities, in addition to holding other plant nutrients. As well, soil that contains biochar retains moisture better than soil without it, making it particularly useful in areas that are prone to drought.