Many sustainability-minded growers are already hip to a simple kind of alchemy that turns downed tree limbs, pruned branches and other waste wood into gardening gold. The process of burning woody biomass in an oxygen-reduced environment yields biochar, an enhanced charcoal that can make for a superior soil amendment.
On Tuesday, June 12, Living Web Farms in Hendersonville will host a workshop that focuses on ways to inoculate biochar with nutrients and beneficial microbes to create a powerful and long-lasting soil conditioner.
Biochar’s porous structure allows it to draw and hold helpful bacteria. And its natural resistance to biodegradation means it can persist in the soil for hundreds, if not thousands, of years, says Living Web’s biochar facility manager, Dan Hettinger, who will present the class along with farm director Patryk Battle. “It’s well documented that biochar-amended soils can have greatly improved nutrient cycling,” says Hettinger. “For gardeners, this means less additional fertilizers are needed over a very long time.”
The biochar method is not new, and it has benefits for the planet beyond improving soil quality. “There are archaeological sites where charcoal was mixed with other nutrient sources and blended with topsoil — these are some of the most fertile soils in the world,” he says, noting terra preta, a dark soil found in the Amazon that was made by ancient humans from charcoal, bone and manure.
“It’s for this reason that biochar production can be a carbon-negative process: We are literally burying stored carbon that would otherwise re-enter the atmosphere by burning or being left to rot.”
There are many simple methods for making biochar at home, says Hettinger. (A video and blog post at livingwebfarms.org offer extensive information on how to do this.) “The best ones are easy to use and burn the excess gases [from the wood] very clean at high temperatures.,” he says, adding that some processes also allow for the reclamation of heat for cooking and other uses.
But biochar alone is not a fertilizer. “Inoculation involves loading raw biochar with nutrients and microbes that contribute to a soil food web — the complex system of microbes that support healthy plants,” Hettinger explains. “Properly inoculated biochar can be used to build very active garden beds, resilient soils for perennials or restore heavily damaged or otherwise lifeless soils.”
During the 90-minute class, Hettinger and Battle will demonstrate — and participants will get hands-on experience with — easy inoculation techniques that implement home compost, compost teas, worm castings and fermented liquid fertilizers. They’ll also discuss best practices for incorporating biochar into soils.
WHAT: Inoculating Biochar
WHERE: Living Web Farms, 220 Grandview Lane, Hendersonville
WHEN: 6-7:30 p.m. Tuesday, June 12
Suggested donation is $10. Register and find more details about biochar at livingwebfarms.org.