Last decade has seen a significantly increased knowledge about phosphate solubilizing microorganisms. Sixty specialists from thirteen countries met in Salamanca to discuss the problems of the high P-unavailability as a soil nutrient for crops, and the hazards of an increasing phosphate input to aquatic habitats from industrial and mining activities, sewage disposal, detergents, and other sources. Updated solutions to enhance P-uptake by plants, bioremediation potential in the rehabilitation of ecosystems, taxonomic characterization interactions with mycorrizae, the physiological and molecular basis of PSM, and possibilities of genetic modifications of rhizospheric microorganisms were among the contributions presented. Challenges in commercializing a phosphate solubilizing microorganism were also outlined by a relevant biotech company. The book will fill a gap in agricultural libraries and it is a wish of the editors to attract the attention of agronomists, environmentalist, technocrats and administrators holding responsibilities in the field of soil conservation and sustainable agricultural production.