Michael Low, the owner of Vermont Biochar, has just published an excellent article on biochar in Permaculture magazine. The article is titled Biochar: how to build soil, lock up carbon & build fertility on the farm. I think you'll find it informative and interesting. I mentioned previously that Rich and I met Michael when we shared the podium speaking at Dartmouth College. We have been in touch several times since then and our initial positive impressions of his knowledge and experience with biochar have continued to grow.