An evolving, living organic/inorganic covering, soil is in dynamic equilibrium with the atmosphere above, the biosphere within, and the geology below. It acts as an anchor for roots, a purveyor of water and nutrients, a residence for a vast community of microorganisms and animals, a sanitizer of the environment, and a source of raw materials for construction and manufacturing. To develop lasting solutions to the challenges of balanced use and stewardship of the Earth, we require a fundamental understanding of soil–from its elastic, porous three-phase system to its components, processes, and reactions. Handbook of Soil Sciences: Properties and Processes, Second Edition is the first of two volumes that form a comprehensive reference on the discipline of soil science. Completely revised and updated to reflect the current state of knowledge, this volume covers the traditional areas of soil science: soil physics, soil chemistry, soil mineralogy, soil biology and biochemistry, and pedology. Contributors discuss the application of physical principles to characterize the soil system and mass and energy transport processes within the critical zone. They present significant advances in soil chemistry; describe how minerals are formed and transformed; and provide an introduction to the soil biota. They also examine geomorphology, land use, hydropedology, and subaqueous soils as well as the classification and digital mapping of soil. Critical elements addressed in each section include: Descriptions of concepts and theories Definitions, approaches, methodologies, and procedures Data in tabular and figure format Extensive references This cohesive handbook provides a thorough understanding of soil science principles and practices based on a rigorous, complete, and up-to-date treatment of the subject matter compiled by leading scientists. It is a resource rich in data, offering professional soil scientists, agronomists, engineers, ecologists, biologists, naturalists, and students their first point of entry into a particular aspect of the soil sciences.