Thanks to all involved for a memorable weekend- if only because it highlighted what a complex issue soil science is. To a degree, I've been focusing on the combustion engineering side of charcoal making, and the next big learning curve is about how biochar works in the soil- to a degree, I gloss over this angle, and just say that it retains water and soluble nutrients. I've lots of questions -good- but the one in my mind at the moment, that I don't remember being touched on, is the role of tree roots in soil- good thing or bad thing? Do the trees rob nutrients from the soil?