Isolation of potential phosphate solubilizing bacteria (PSBs) suitable for specific crop and soil types has tremendous scope for improving the P nutrition of crops. Continuous application of soluble fertilizers increased the fixed P in soil during course of time. This fixed form of P can be made available to crops through microbial solubilization very effectively. Hence, identifying potential phosphate solubilizers suitable to specific soil type from the crop rhizosphere is gaining importance in sustainable nutrient management. Rock phosphate minerals are another the cheap nutrient input which can be harnessed along with phosphate solubilizers for improving the P nutrition crops. This book has highlighted the isolation of potential PSBs from the sunflower grown in black soils. This book also suggests the methodology for identifying potential PSB based on solubilization index and important biochemical tests. This book will be very useful to students, research scholars and academicians.