Cooking better biochar: Study improves recipe for soil additive
HOUSTON — (March 22, 2012) — Backyard gardeners who make their own charcoal soil additives, or biochar, should take care to heat their charcoal to at least 450 degrees Celsius to ensure that water and nutrients get to their plants, according to a new study by Rice University scientists.
The study, published this week in the Journal of Biomass and Bioenergy, is timely because biochar is attracting thousands of amateur and professional gardeners, and some companies are also scaling up industrial biochar production.
“When it’s done right, adding biochar to soil can improve hydrology and make more nutrients available to plants,” said Rice biogeochemist Caroline Masiello, the lead researcher on the new study.
The practice of adding biochar to topsoil to boost crop growth goes back centuries, but in recent years, international interest groups have begun touting biochar’s climate benefits as well. Biochar removes carbon from the atmosphere and locks it into the soil for hundreds and sometimes thousands of years.