WOODSTOCK — Dorie Seavey watched as Ken Scherer chucked loads of barberry, along with dry, downed maple, red pine and ash boughs, into a massive metal kiln in her yard.
What looks like a backyard burn pile Scherer sees as “biomass,” a catch-all term that includes forest and crop residue — such as what Seavey’s collected — as well as animal and food waste. It’s the world’s most abundant renewable carbon source, and people like Scherer think it’s time we put it to good use.
Scherer will burn the biomass in the kiln, rather than as a smoky open fire. Burned at high temperatures with little oxygen, a process called pyrolysis, biomass becomes “biochar,” a substance that can be spread on agricultural land to improve soil quality.
This is why Seavey invited Scherer, an organic farmer from upstate New York, to her property in late June. Making biochar, and teaching others how to do so and why they should, is his bread and butter.
“With a hotter, cleaner burn, this results in charcoal that can be crushed and returned to the soil,” Scherer said of the burn product building up in the bottom of the kiln.
Biochar is porous and highly absorbent. When it’s spread over pastures and cropland, it can act as a soil amender and buffer that increases a soil’s capacity to retain water, resist erosion and filter out pollutants.
“More space in your soil means more life,” Scherer said.
Seavey, a climate economist who moved from Cape Cod in Massachusetts onto 47 acres in Woodstock last June, is interested in forestry management strategies that capture carbon, mitigating climate change.
“In terms of giving off the least noxious compounds, I want to learn how to make the burn as clean as possible,” said Seavey, who’s turned to biochar as an alternative to smoky, open burn piles.
Seavey had spent several hours tearing the barberry, an invasive bush that looks like barbed wire, out of her yard. Now in the oxygen-limiting kiln, which requires over 1,600 pounds of woody debris to fill, it has found new life.
The kiln is portable: It can be dismantled and lie flat in the bed of a truck or in a trailer. Scherer is traveling the country running demonstrations similar to this one for the Biochar Coalition, an organization founded in Nevada aimed at spreading the word about the benefits of biochar.
When not on the road, Scherer runs K Organics on 17 acres in Boston, N.Y., near Lake Erie, where he makes natural fertilizers like “bug frass,” or insect excrement.
“I make about 60 pounds a week of bug poop,” Scherer said.
Biochar mixed with frass makes for a nutrient-rich fertilizer and is just one of many ways that gardeners and farmers are experimenting with the creation of closed, organic agricultural systems.
Seavey’s neighbor, Amy Halley, came with two of her children to watch Scherer work the kiln.
Halley and her husband, Ben, own and operate Second Wind Farm down the road, where they raise around two dozen cattle on a rotational grazing system, another process that sequesters carbon by keeping grass carbon-stores healthy and intact.
“We’ve really been thinking about soil health and lower emissions from the beginning,” said Halley, who sometimes incorporates Seavey’s land into her grazing rotation.
A common way that biochar gets incorporated into soils is through livestock grazing, when cattle trample and grind the organic mix into the ground.
“Animals are just great for biochar,” Scherer said.
Burning for biochar most commonly occurs in the western United States, where the process thins out woody debris on the forest floor that contributes to wildfire risk. While this is certainly still a benefit in New England, biochar would likely be most useful for building productive soil without the use of chemical fertilizers.
“The tree died; it did its thing. How can we keep this tree’s legacy alive?” Scherer asked, nodding toward the biomass pile he’d been feeding into the kiln.
“We’re using the things that are around. This closes the loop.”
Frances Mize is a Report for America corps member. She can be reached at fmize@vnews.com or 603-727-3242.