Inthapanya Sangkhom, Leng R A and Preston T R 2012 Biochar lowers net methane production from rumen fluid in vitro. Proceedings of the International Conference "Livestock-Based Farming Systems, Renewable  Resources and the Environment", 6-9 June 2012, Dalat, Vietnam (Editors: Reg Preston and Sisomphone Southavong) http:/www.mekarn.org/workshops/dalat2012/html/sang1.htm