I started using biochar more than a year ago. Check out "terra preta" on Wikipedia (some good links there). There is also a "biochar bc" group on google. Since using biochar I have found improved soil structure and fertility. Plants grow like crazy! The charcoal apparently hangs onto nutrients and provides an environment for essential micro-organisms necessary for healthy plant growth. There is a bit of an art to making biochar, but I also use the charcoal produced from our woodstove. There is a lot of interest in using biochar in farming to recover soil texture, etc., with university research groups looking into ways of producing terra preta. Anyone else into biochar?