With an emphasis on the fundamentals, this book explores the important world of soils and the principles that can be used to minimize the degradation and destruction of one of our most important natural resources. Fully updated in this edition, it includes the latest information on soil colloids; nutrient cycles and soil fertility; and soils and chemical pollution. This edition is filled with hundreds of new figures and photos and continues to use examples from many fields, including agriculture, forestry, and natural resources. Taking an ecological approach, it emphasizes how the soil system is interconnected and the principles behind each soil concept. Updated information in this edition includes: Engineering properties of soils Expanded treatment of soil quality, soil degradation and soil resilience A new section on septic tank drain fields Expanded section on irrigation management A new section on wetlands and their poorly aerated soils For individuals who study the science of soil, and those who make a profession of it.