From "Shifting Paradigms on Biochar: Micro/Nano-structures and Soluble Components are Responsible for its Plant-Growth Promoting Ability”, S Joseph, ER Graber, C Chia, P Munroe, S Donne, T Thomas , Nielsen S, C Marjo, H Rutlidge, G X Pan, Xiaorong Fan, P Taylor , A Rawal, J Hook, Carbon Management, Vol 4, No. 3 (2013).