Hi all, I highly recommend listening to an edition of KPFA's 'Against The Grain' in which a studier of economics, social structure, and the ecology of soil systems, lays out an excellent basic holistic summary of soil dynamics as the crucial interface between the atmosphere, hydrosphere, planetary crust, living systems and human social systems. You can stream or download the program at: http://www.kpfa.org/archives/index.php?arch=25717 -- "I am not a liberator. Liberators do not exist. The people liberate themselves." – Che Guevara