December 2021
How did you get started with biochar?
I have always been interested in forests and climate change. I grew up in Spokane and loved the outdoors. In college I studied environmental journalism and took graduate level courses at the Yale School of Forestry. But after graduate school I was feeling a strong need to apply the knowledge I learned in the academy to hands on forestry. There seemed to be a big disconnect between the academic world and the realities of implementing regenerative practices on the ground. I purchased undeveloped land here on the San Juan Islands to homestead, and made a big mess felling trees to clear it for a small farm. Some of the local farmers stopped by and said: “What have you done, son?” They were the ones who first told me about biochar. I made a call to Dr. Tom DeLuca, a biochar researcher who taught at the University of Washington at the time, and he ended up working with me and Dr. Si Gao on a series farm biochar trials.
Is that collaboration with Dr. DeLuca still going on?
Yes. We are just finishing up a project looking at the impacts of biochar on forest soils and the growth characteristics of tree saplings. We have found that biochar improves the water holding capacity of our forest soils and it also reduces the basal respiration rate of soils, which means that the biochar is helping to stabilize the other, more volatile carbon in the soil. We will have a final report out soon.
You have some big biochar forestry projects going on now. How did that come about?
We have a great need for fuels reduction to address ongoing drought and wildfire threats in San Juan County. In 2020 the San Juan Islands Conservation District launched the Islands Conservation Corps (ICC) to create and train an ecology workforce. This is hard work, so we need people. What we are doing meets a lot of different conservation objectives such as oak woodland restoration. It also helps protect our communities from wildfire. The electric company, OPALCO, also supports us to clear vegetation along utility corridors, work that we do in partnership with forestry contractor Rainshadow Consulting.
What have you been learning?
My biggest learning this year has been the art of coordinating people. I am getting to experience this fascinating intersection between environmental science and human psychology. Our crew has done an incredible job of coming together as a community, and it’s a powerful example of how human synergy also fosters the best work in ecology. Our crew balances field time with taking courses at Western Washington University’s College of the Environment, Huxley College. They are studying forest restoration, GIS, biostatistics and things like that. We had 70 applicants for the program and chose only 10. The students get a stipend and 20 free college credits. With this program, they are gaining many valuable skills in chainsaw work, burning practices, planting, riparian zone restoration, all in coordination with their academic coursework. We are bridging that gap between the university and the field.
What techniques are you using to make biochar in the woods?
We use the Conservation Burn technique. We make standard size burn piles, about 5 feet in diameter. By next year we will have as many as 1,500 piles on different preserves across San Juan County. We light them on the top to get a good flaming combustion going that reduces smoke. Then, we put out the coals at the end to save the char. We have a 1,300-gallon water truck and we use a combination of spraying water and raking. For very remote sites we have five-gallon backpack pumps. One backpack pump can extinguish two piles.
What’s coming up next for you?
Next year the ICC program will launch a Master of Arts in Ecological Restoration from Huxley College, so we have opportunities for more research. We are excited to formalize more research in conservation burn practices, and develop a replicated treatment system to get reliable data. We will try separating size classes, different densities, and using a teepee style construction with different angles. We want to weigh some feedstocks so we can get an estimate of biochar production efficiencies. We are also working with DNR to document our practices so that DNR can specify Conservation Burn as a practice. This could lead to reduced permitting costs over conventional burns for those who use the practice.
Read more about Kai Hoffman-Krull and the Islands Conservation Corps here:
Hear more from Kai at the USBI Biochar in the Woods Online Workshop on January 27, 2022. Register here: https://www.eventbrite.com/e/biochar-in-the-woods-learn-how-to-use-biochar-for-forest-resilience-tickets-207366166787