Agricultural Microbiology encompasses a broad range of study area.As microbes present in everywhere, microbiology embraces other disciplines also. Biofertilizers are gaining momentum recently due to the increasing emphasis on maintenance of soil health,minimize environmental pollution and cut down the use of chemicals in agriculture. It generate plant nutrients like nitrogen and phosphorous through their activity in the rhizosphere and make available to the plant. Rice is a stable food for half of the world. Water resource limitation threaten the sustainability of irrigated rice systems.Water saving methods that can offer greater water productivity are needed to keep up the future water demand. Aerobic rice is a new water saving method in which the fields are remain unsaturated throughout the season. It will reduce the water use and methane emission too. The book is a dissertation work discussed various aspects of rhizosphere microbial population.Each chapter is discussed in a simplified style and methodologies are written in a manner suited to those carrying research work.The matter has been lucidly presented, orderly arranged and profusely illustrated.