Explore the benefits of incorporating biochar into composting processes. Understand its impact on soil health, crop yields, and environmental sustainability. Dive into case studies from Rexius and Pacific Biochar, and learn application tips for farming.
Biochar is a carbon-rich product made from biomass like leaves, wood chips, and agricultural residues. When added to compost, biochar can:
Improving your soil can lead to a more productive garden or farm. While biochar might be more costly upfront, the potential yield increases and environmental benefits make it a worthy investment.
Visit the Biochar Atlas at pnwbiochar.org/tools.
Adding biochar activates the composting process by enhancing the activity of microorganisms, which raises the temperature, reduces composting time, and speeds up stabilization of the compost.1 The use of biochar during the compost process yields a product comparable to those obtained with mineral fertilizer additions with a lower environmental impact.2 More recently, researchers found that benefits of co-composting with biochar far outweighed any drawbacks or side-effects when compared with other amendments. The quality of biochar-compost improves soil health and can boost crop yields.3 To use biochar in the composting process, the material should be added just like any other composting ingredient using existing equipment. The scientific literature and experience of composters indicate that the best ratio of biochar to compost is in the range of 5% to 10% by volume. Adding more than 20% or 30% is not recommended as an excessive amount can interfere with biodegradation.4
Increased production and savings: Composters who use biochar often see processing time reduced. More importantly, they report cost savings from turning piles less frequently. The fuel and labor savings are even more appealing than reducing compost time.
Higher quality material: Increased nitrogen in the final product gives biochar-compost a better nutrient profile than compost alone, making it a better soil amendment.
Interested in learning more about the economics of biochar? See the Biochar Atlas-Cost Benefit Analysis tool, which guides users to assess whether biochar is a good investment for your soil. pnwbiochar.org/tools/cba
Biochar is made from a variety of biogenic biomass sources (leaves, wood chips, agricultural residues, orchard pruning, vineyard cuttings, and many others). As a biogenic resource, biochar feedstocks are natural and renewable. Many locations across the United States have excess biomass with little or no market value. These materials are often either burned or sent to a landfill. Compost companies provide a valuable mechanism to divert large-scale waste biomass resources and make them into something that can help improve soils. Biochar is a new product made from low-value material that can help add value to compost. In so many communities, excess biomass shows up at landfills for disposal. Every fall, when the leaves drop, the level of waste biomass that gets sent to the landfill is disturbing. This is also true for the debris from a strong windstorm or ice storm event. If we can develop new markets for low-value biomass (like biochar), we are helping to create natural, renewable, locally produced material that can benefit people and the environment.
CHALLENGE/OPPORTUNITY: Jack Hoeck, VP of Environmental Services at Rexius, a family-owned compost and soil producer in Oregon, heard about the benefits of biochar through conversations with John Miedema of BioLogical Carbon. He was intrigued by the material as a possible new amendment to help the company produce better compost.
SOLUTION/APPROACH: Rexius started by creating two compost windrows, one with biochar and one without. In the windrow with 5% biochar by volume added, the compost-biochar had more moisture, nitrates, and other nutrients than the pile without biochar. Overall, the quality was better in the biochar windrow.
RESULTS: Since using biochar in the compost process, Rexius has continued to record higher nutrient values in their biochar-compost than compost without biochar. They also report higher beneficial plant bacteria and microbes compared to compost without biochar. Higher nutrients and more beneficial microbes create a higher value soil product that commands a better price for their gardening products. Jordan Launch of Rexius mentioned there are multiple benefits from incorporating biochar in their composting process, including labor and fuel savings from not having to turn the compost pile as often. This, along with a higher value end product, makes investing in biochar well worth it.
CONCLUSION: "The better your soil, the more productive your garden will be (whether that is better tomatoes, more colorful and vibrant flowers, or higher yields of lettuce or kale). Biochar and biochar-compost help improve soil. Though the material costs more, it results in greater yields and makes it well worth the investment."
CHALLENGE/OPPORTUNITY: Oasis Vineyard in King City, CA, was interested in trying different amendments to study how biochar and compost treatments affect soil water use, soil health, vine growth, harvest yields, and grape quality. The vineyard had soils with low organic matter and needed to conserve more water.
SOLUTION/APPROACH: Starting in 2016, the Sonoma Ecology Center, UC Riverside, and Pacific Biochar worked with the Oasis Vineyard manager Monterey Pacific Inc. to develop a multi-year field trial with funding from the California Department of Water Resources. Treatments included biochar only, compost only, biochar-compost, and a control (no amendment).
RESULTS: Some findings include:
CONCLUSION: Biochar and compost treatments can improve water use efficiency, vine growth, harvest yields, and soil health for vineyards planted on low organic matter sandy soil. The vineyard manager, Monterey Pacific, said the return on investment for adding biochar paid off in the first grape harvest with higher profit expected over the life of the vines.
Biochar compost products can be spread using the same type of equipment farmers use to spread compost. It can either be worked into the soil using a plow or side-casting along rows, as in the case of biochar-compost vineyard applications. The amount of biochar-compost you should apply to your soil will depend on various factors. To learn more about how biochar can help your soil, view the Biochar Atlas at pnwbiochar.org/tools. The Biochar Selector tool can guide you on the amount of biochar for your soil: pnwbiochar.org/tools/selector.