The umbrella of microbial biotechnology in agriculture covers numerous scientific activities, ranging from production of biofertilizers to that of microbial pesticides; from biological nitrogen fixation to ligno-cellulose degradation; from production of biomass and bio-fuels to transgenic plants. The object of this book is to cover comprehensively different groups of microorganisms used for sustained productivity of plants important in agriculture, horticulture and forestry. The readers may appreciate the potential and fascination of biotechnological approaches used for utilizing microorganisms in sustainable agriculture, horticulture and forestry. The book is a comprehensive and detailed analysis of the subject. The book will be useful to students, teachers and researchers interested in microbiology, biotechnology, natural resource management, organic farming and sustainable agriculture, horticulture and forestry.