For eighty years, The Nature and Properties of Soils has delivered a complete, current, and reliable introduction to the study of soils in a manner that is both fascinating and intellectually satisfying. Whether used as the core textbook for college courses introducing the fundamentals of soil science, or as a comprehensive reference on the professional soil scientist's bookshelf, the book is widely recognized as the authoritative source for all of the latest information related to this exciting field. In this same tradition of excellence, this new Thirteenth Edition has been completely updated and expanded to provide fresh and essential new coverage of topics critically important to the future role of soils in natural resource sciences, including wetlands, septic drain fields, salt-affected soils, bioremediation, soil ecology, nutrient and irrigation management, soil hydrology, and new orders in Soil Taxonomy. More specifically, this new volume represents significant expansion to include valuable information with regard to all of the following: the pedosphere concept subaqueous soils ethnopedology x-ray diffraction non-silicate colloids inner/outer sphere complexes nuclear contamination effective CEC lead contamination acid and non-acid cation saturation human-influenced acidity calcium and magnesium in plants/soils irrigation water quality biomolecule binding soil food web ecology forest nutrient management phosphorus site index indicators of soil quality proton balance approach to soil acidity Accompanying this book-and all new to this thirteenth edition-is a companion website containing many unique and engaging opportunities for further study. The URL is http://www.prenhall.com/brady .