MONTEREY COUNTY — Elkhorn Slough Foundation (ESF) is currently producing beneficial biochar from invasive eucalyptus trees removed to restore native ecosystems around Elkhorn Slough.
In partnership with ESF, soil scientist Arun Jani of California State University Monterey Bay (CSUMB) is now studying the impacts of this carbon-rich biochar on farm productivity, water conservation and environmental health.
Biochar is a form of charcoal typically used as a soil amendment to improve water and nutrient retention, increase fertility and sequester carbon. Because biochar is so porous, it holds water and nutrients in the ground like a sponge, creating habitat for beneficial microbes and reducing harmful runoff and erosion.
Because it is highly stable, this form of carbon resists decomposition and remains in the ground for thousands of years, where it won’t contribute to climate change.
“In a region with declining groundwater and wetland pollution from farming,” said Jani, “the use of biochar could address resource constraints that threaten the base of our economy and ecology.”
The biochar is being produced by project partner Ventana Forestry at ESF’s Brothers Ranch using a large mobile kiln called a Carbonator, which converts wood waste to biochar in a high-temperature, low-oxygen process known as pyrolysis.
“For centuries, Indigenous people used cultural fire to maintain healthy forests,” explained Tom Little Bear Nason of Ventana Forestry, “but much of today’s landscape has gone generations without beneficial burning, leaving an overload of woody material and non-native trees. With Ventana Forestry’s Carbonator — the cleanest-burning biochar system in operation — we can transform that excess biomass into a valuable resource.”
The work was supported by a $1.77 million grant from Cal Fire, funding the removal of fire-prone eucalyptus trees near the town of Las Lomas in unincorporated Monterey County.
“Ecological restoration and wildfire prevention efforts go hand in hand,” said Cal Fire’s Tim Montgomery. “Thanks to ESF’s efforts, this project is creating a more wildfire resilient landscape, protecting watersheds, improving habitat and increasing public safety.”
Jani first saw biochar made from eucalyptus used successfully as a soil amendment in similar environments in South Africa. His current study, now entering its second year at a nearby organic farm, is the first field research conducted on eucalyptus biochar in the United States. Initial funding for this research came from the California State University Agriculture Research Institute.
ESF and Ventana Forestry made eucalyptus biochar together once before, on a smaller scale, at ESF’s Elkhorn Highlands Reserve in 2023. That effort converted 8,000 tons of eucalyptus logs into 200 tons of biochar, and was the source of the biochar now being studied by Jani.
Ongoing biochar production at ESF’s Brothers Ranch is slated to run through mid-March.
Elkhorn Slough Foundation is a community-supported nonprofit land trust whose mission is to conserve and restore Elkhorn Slough and its watershed. ESF protects more than 4,200 acres of rare habitat, including oak woodlands, coastal prairie, maritime chaparral and wetlands. For more information, visit elkhornslough.org.
