Biochar Standards

Written by E. Philip Small on February 3, 2011

In a very positive development for biochar stakeholders, a Biochar Characterization Standard Working Group is being convened by the International Biochar Initiative.

The goal of this working group is to determine definitively “what is biochar?” For years, many have wondered how biochar differs from traditional charcoal. The answer is highly technical. In addition, there are myriad ways to produce biochar, all resulting in different properties and effects in soil. With a firm, thoughtful standard in place, biochar producers and end-users will have definitive guidelines on how to produce and/or purchase the highest quality char for a desired effect.

All of us working with biochar recognize this as a critically important issue. One is left to wonder how much more effective recent federal research would have been if it had included a robust characterization of the biochar stock provided by the fast pyrolysis industries.

That research often does a poor job in controlling for the liming effect of the biochar. How much of a boost to productivity would you get with just the liming effect absent the charcoal? This clearly matters and, as I have shared with some of the Working Group members, I would like to see acid neutralizing potential or ANP ( in units of calcium carbonate equivalent or CCE) be at least considered as a labeling requirement. Other aspects are more critical, but even a coarse rating of low-med-high ANP would be very useful. Acid neutralizing potential is usually low in biochar, between 1 and 2% CCE. On the other hand, some biochar stocks can have substantial ANP above 20% and as a consequence could alter forested soil ecology in unintended ways. Out here in the inland Western US and Canada, our soils are less acidic than in the East, thus the same ANP application basis that will have no discernible effect on soil pH in the East, could move our soils from pH 7 to 8. That concern is what keeps Avista’s Kettle Falls mill-waste-to-energy, high carbon, ash going into a private landfill rather than beneficially reused on our forests here, whereas ash application is accepted practice in the Eastern states. Personally, I think the Kettle Falls material could, and should, be land applied. Its just a matter of finding the appropriate site conditions.