Biochar for Molokai
By Glenn I. Teves, UH CTAHR County Extension Agent
Josiah Hunt of Pacific Biochar is the mover and shaker in the use of biochar in Hawaii and other areas of the world, and will be presenting a workshop on Thursday, Nov. 12 at 5 p.m. at UH Maui College-Molokai Farm located in the Molokai Agricultural Park.
Although the word “biochar” may be new, the idea of using charcoal for food production is not new. In the Amazon Basin, unearthed areas have been found to contain layers of biochar that enriched the poor soils of these high rainfall regions. High rainfall in the tropics can leach or wash away key nutrients, especially bases such as Calcium, Magnesium, and Potassium, key elements for optimal plant growth, and these conditions are found in high rainfall areas of Molokai.
A key in making biochar is a quicken burn with a roaring fire while limiting oxygen to burn off volatile oils, resins, and tars. The type of tree used, and the method in which biochar is produced greatly affects its quality and effectiveness as a soil additive, but all invasive species are good candidates for producing biochar, including Christmas Berry, Koa Haole, and Formosa koa which we have an abundant supply. A sustainable model for biochar production is the use of tree material from landfill tree waste and invasive species so it doesn’t compete with wood with other important uses.
Ho`olehua farmer John Freeman has been experimenting with biochar in organic papaya production, and results indicate better yields, larger fruit, and higher quality when using biochar as soil amendment. Although biochar is just one additional tool in a farmer’s tool box, many other tools need to be in place to assure a high quality crop, including balanced nutrition, high soil organic matter, proper acidity or pH, proper water management, and wind protection for tall crops such as papaya. Using biochar of various pore sizes creates niches of a greater diversity for beneficial microorganisms and this improvement in soil has a long-term effect.
The use of biochar has a long history in Korea and Japan, and is being revived through heightened interest in sustainable and natural farming systems in Hawaii. With the El Nino conditions we’ve experienced this summer, farmers need to tighten up their management system in order to quickly adjust to changing climatic conditions.
The public is invited. For more information, contact the UH CTAHR Extension Office at 567-6929. This workshop is sponsored by the County of Maui Office of Economic Development – Kuha`o Center, Makakuoha Cooperative, and the UH College of Tropical Agriculture and Human Resources.