“The soil is home to a large number of living organisms thus also known as the soul of infinite life. Living organisms in soil are broadly grouped into macro-organisms such as macroalgae, termites, earthworms, etc. and microorganisms include fungi, actinomycetes, bacteria, protozoa, etc. Soil acts not only as a medium for plant growth and microbiological activity, but also as a sink and recycling factory for numerous dead organic matter. The breakdown of organic matter leads to the availability of nutrients for plants and other organisms in the soil. Without the activities of microbes, the dead and un-degraded matter would accumulate and litter the soil surface, and there would be no available food in the soil to sustain plants. Soil organisms play an important role in preventing nutrient losses through leaching, maintaining soil structure and promoting plant growth and health through the production of various secondary metabolites. This chapter highlights soil-plant relationships, plant growth and microorganisms, microbial diversity, nutrient cycling, and nutrient pathways and mechanisms.”
