BLOOMINGTON, Ind. (AP) — Looking for ways to improve the soil in the Hoosier National Forest as well as better utilize woody debris left over after timber harvests led Chad Menke, a hydrologist with the U.S. Forest Service, to try something new: making biochar.
It’s something that is done on some Forest Service properties in the West, where there’s more timber harvesting and a need to capture moisture and amend the soil. But the biochar produced by K&K Dirtworks of Evanston was the first that’s been used in the Hoosier National Forest — and the first in the eastern region of the Forest Service.
The first experimental site was a half-acre section within the Uniontown North Restoration Project in Crawford County. The area had a timber harvest that left lots of woody debris, known as slack, on the compacted soil. At most timber harvest sites, the slack is left to decay, which does eventually add nutrients to the soil.
In early May, the slack was burned in a special kiln for eight hours. Five tons of biochar was produced and applied to the half-acre area, which was later seeded with native vegetation. The area was chosen for the experiment because it isn’t likely to get a lot of recreational use that would disturb the soil and plantings.
“I’m hoping we can utilize it in a number of applications,” Menke said.
Those would include other timber harvests but also areas where trees are blown down due to storms and areas that have been disturbed with bare soil needing more nutrients and better filtration so plants and trees can grow. Plans for the first test site are to create early successional habitat — with bushes, shrubs and small trees that provide habitat for many species of wildlife.
“We’re using our own material left behind,” Menke said, adding biochar also increases the growth rate of vegetation.
While holding moisture in the soil isn’t a real problem in the Hoosier National Forest, the biochar can help improve water quality, Menke said. Biochar holds water in soils, helping control erosion. It also holds nutrients within the soil, and since it’s a carbon-based product, it can mitigate climate change by increasing the carbon pool within soils.
The Hoosier National Forest is shipping samples of the biochar to the regional lab to assess how much carbon is in the finished product and the overall quality of the char produced.
Menke plans to determine how cost-effective creating and using biochar will be for the Forest Service and other agencies and landowners in Indiana and beyond.
“We want to make it economically viable, a long-term bang for our buck,” he said. “If when a (timber) harvester is done, he can leave the excess (slack) in one place and we can figure out the cost versus benefit at each site.”
The study will continue for at least two years. The hope is to compare the biochar area with other forest projects to see what treatments for soil are most effective and efficient.
“I would like to see more strategies for harvests,” Menke said, adding that the money needed for the study came from funds from the timber harvest. The harvests also help fund projects including water crossing improvements, invasive plant removal and building and maintaining trails.
Once an area in the national forest is harvested for timber, Menke said it’s left alone for 20 years or more.
“This is to replenish what has been done,” he said. “When you walk away from that replenished site, you won’t touch it for another 20 years.”
Source: The Herald-Times