Soil is the most important natural non-renewable resource developed over a longer period of time due to weathering of rocks and subsequently enrichment of organic matter. Soil provides habitat for numerous microorganisms and serves as a natural medium for plant growth, thereby providing the plants with anchorage, nutrients and water to sustain the growth. Soil also serves as a universal sink for all types of pollutants, purifies ground water and is a major reserve of carbon in the universe. The role of soils to provide ecosystem services, maintenance of environmental/human health and ensuring the food security makes it as the most important and basic natural resource. Soil Science helps us to elaborate and understand how the soils provide all these services. Soil Science also provides us the basic knowledge dealing with the origin of the soil parent material, weathering of parent material and the formation of soils, morphological, physico-chemical and biological features of soils, classification of soils and role of soils in the provision and maintenance of ecosystem services, food security and environmental quality. This book encompasses the various processes, functions and behaviour of soils very comprehensively to acquaint the students of soil, plant and environmental sciences about their role to perform different agricultural and environmental functions.