Biochar Carbon Stability Test Method: An assessment of methods to determine biochar

Twenty seven methods currently used to characterize biochar were assessed in terms of their usefulness to determine the stability of biochar carbon in the environment. The International Biochar Initiative (IBI), which led the effort, gathered fourteen world-class experts in different fields of biochar relevant to stability, who guided the process for obtaining a simple, yet reliable, measure for biochar stability. Important requisites were defined for the test, including cost, repeatability and availability. Identification of a cost-effective, scientifically valid test to measure the stable carbon component of biochar is imperative to distinguish biochar from non-biochar (non-stable) materials, and to develop a biochar offset protocol for carbon markets. The stability of biochar carbon in soils makes it a highly promising product for consideration as a strategy for climate change mitigation. The definition of the variable BC+100, which stands for the amount of biochar carbon that is expected to remain stable after 100 years, along with predictions of stability based on simple (Alpha) and more sophisticated (Beta) 1 Norwegian Institute for Agricultural and Environmental Research – Bioforsk, Høgskoleveien 7, N-1432 Ås, Norway 2 Department of Geological Science, University of Florida, 241 Williamson Hall, P. O. Box 112120, Gainesville, Florida 32611-2120, United States 3 Rural Climate Solutions, University of New England, NSW Department of Primary Industries, Armidale 2351, Australia 4 School of Physical Sciences, University of Kent, CT2 7NH, UK 5 NSW Department of Primary Industries, PO Box 100, Beecroft NSW 2119, Australia 6 Soil Biogeochemistry, Martin-Luther-Univ. Halle-Wittenberg, von-Seckendorff-Platz 3, 06120 Halle, Germany 7 Department of Earth Science, 6100 Main St. MS 126, Rice University, Houston, TX 77005, United States 8 EcoEra, Orkestergatan 21 181, 42139 Göteborg, Sweden 9 Control Laboratories, Inc., 42 Hangar Way, Watsonville, CA 95076, United States 10 Department of Crop and Soil Sciences, Cornell University, Ithaca, NY 14853, United States 11 Institute of Natural Resources, Massey University, Palmerston North 4442, New Zealand 12 Biochar Solutions Inc., PO Box 2048, Carbondale, CO 81623, United States 13 UK Biochar Research Centre (UKBRC), School of GeoSciences, University of Edinburgh, Crew Building, The King's Buildings, Edinburgh, EH9 3JN, UK 14 School of Material Science and Engineering, University of New South Wales, 2052 Sydney, Australia