Research is underway that could lead to more uses for waste wood, a U.S. Forest Service researcher says.
Instead of thinning stands to boost productivity and burning the resulting slashpiles, researchers believe turning it into biochar — a supplement made of charred biological matter — would be better for long-term carbon storage and boosting soil’s nutrient- and moisture-holding capacities.
“We’re hoping we can make a change in forest management,” said Deborah Page-Dumroese, research soil scientist with the U.S. Forest Service Rocky Mountain Research Station in Moscow, Idaho. “Instead of making slashpiles, we can actually use that waste wood for a benefit.”
Textured soils with little organic matter content responded better than soils with higher organic content. Agricultural soils typically show better response to biochar because they’re lower in organic matter, Page-Dumroese said.
Biochar is applied differently on forest soils. It is added to the surface instead of being incorporated into farm land. It takes several years for biochar to move into forest soils.
As more areas experience drought, an increase in water-holding capacity extends the growing season, Page-Dumroese said. Organic matter also acts as a sponge during flooding, retaining more moisture.
Page-Dumroese plans to continue her research. The biggest benefit of biochar is carbon sequestration, she said.
Researchers primarily focus on matching biochar to the proper site. Some forest sites do show an increase in the growth of overstory trees.
“We see small changes, but we still see above-ground growth changes,” Page-Dumroese said.
The sites most likely to require biochar include mine land sites, overgrazed areas and highly compacted forest sites with organic matter removed due to fire.
Page-Dumroese said some mine sites are showing an increase in plant survival.
She uses a mixed conifer feedstock or a mix of pinyon pine and juniper for biochar.
Page-Dumroese said roughly 30 percent of materials used to make biochar on an acre should be returned to that particular acre, but the rest could be sold for use on gardens or farms. She advised potential customers to consider the source of the biochar and its pH levels.
Howard Boyte, CEO of Walking Point Farms, a veteran-owned agritech business in Tigard, Ore., said the forest service approached him several years about commercializing biochar. The company plans to market a commercial product.
Page-Dumroese’s lab is the lead on researching the project with Oregon State University, Boyte said.
Biochar is expensive right now, Boyte said. The government would need to require biochar use for food it purchases for prisons, military and USDA food programs for it to gain traction with farmers, he said.