A microorganism is a microscopic organism that may exist in single-celled form or in colony of cells. The study of microorganisms that are present in the soil is known as soil microbiology. It is also concerned with the study of the functions of microorganisms and how they affect the properties of the soil. These microorganisms fix the nitrogen content in the soil and release oxygen in the atmosphere. Some of these microorganisms present in the soil are bacteria, fungi, protozoa, actinomycetes and algae. This area of study is majorly used in agriculture. It makes the minerals and nutrients present in soil available to the plants and help them produce hormones that initiate growth. This book unfolds the innovative aspects related to this field which will be crucial for the holistic understanding of the subject matter. It is a valuable compilation of topics, ranging from the basic to the most complex theories and principles in the field of soil microbiology. This book is an essential guide for both academicians and those who wish to pursue this discipline further.