This book integrates analysis of soil systems with the strategies and methods for creating sustainable soil systems to provide the most comprehensive reference available. More than 100 experts from 6 continents, representing a wide variety of disciplines, examine soil agents and processes, strategies and methods for sustainable soil systems, and related issues such as crop management, climate impacts, economic and policy concerns for fertility management, and modeling for assessment of soil systems. The text examines soils in the tropics, temperate zones, and under arid and semi-arid conditions. The book is ideal for scientists, researchers, and policymakers involved in plant, crop, and soil science.