This four-volume set, edited by leading experts in soil science, brings together in one collection a series of papers that have been fundamental to the development of soil science as a defined discipline. Volume I contains papers that look at the soil as a natural body and speculate on how it was formed, the extent of its global coverage, and the many complex interactions with the biosphere, hydrosphere, atmosphere, and lithosphere. It focuses its attention on the 'what' of the pedosphere and the extent of our current understanding of it.Volume II focuses on the 'how' of soils, the understanding of fundamental processes. It is concerned with the integration of physics, chemistry, biology and mineralogy to understand fundamental soil properties and processes that control transport, cycling, speciation and bioavailability of elements or molecules. These phenomena are studied at multiple scales ranging from atomic to global. Volume III contains papers on 'why' soil science is important to society. It demonstrates the application of fundamental knowledge to solve social, economic, and environmental challenges of major societal and scientific interest. It can be considered the applied segment of soil science to ensure that soils are used and managed in a sustainable manner.Volume IV contains papers that are more general and address the transfer of knowledge to segments of society where soil science is misunderstood or under-appreciated. It addresses public literacy in soil science, education, international conventions, consequences of human activities on soil ecosystems, policy issues, food security, and philosophy and history of the discipline.