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Soil Formation deals with qualitative and quantitative aspects of soil formation (or pedogenesis) and the underlying chemical, biological, and physical processes. The starting point of the text is the process - and not soil classification. Effects of weathering and new formation of minerals, mobilisation, transport, and breakdown or immobilisation of dissolved and suspended compounds are discussed. Soil processes and profiles are discussed in relation to the landscape, the geosphere, and the biosphere. Emphasis lies on the universality of soil-forming processes in past and present, and on the soil as a dynamic entity that forms part of the total environment. Complexity of genetic processes in time and space is given much attention. The text gives many examples from literature and places some in a new light. The reader is guided through the subject matter by a large number of questions and problems to help understand and synthesis the material. Answers to all questions are included. This second edition has been updated to reflect recent discoveries. Printing errors have been corrected, and new photographs support the text.

Soils form a unique and irreplaceable essential resource for all terrestrial organisms, including man. Soils form not only the very thin outer skin of the earth's crust that is exploited by plant roots for anchorage and supply of water and nutrients. Soils are complex natural bodies formed under the influence of plants, microorganisms and soil animals, water and air from their parent material, i.e. solid rock or unconsolidated sediments. Physically, chemically and mineralogically they usually differ strongly from the parent material, and normally are far more suitable as a rooting medium for plants. In addition to serving as a substrate for plant growth, including crops and pasture, soils play a dominant role in the biogeochemical cycling of water, carbon, nitrogen and other elements, influencing the chemical composition and turnover rates of substances in the atmosphere and the hydrosphere. Soils take decades to millennia to form. We tread on them and do not usually see their interior, so we tend to take them for granted. But improper and abusive agricultural management, careless land- clearing and reclamation, man-induced erosion, salinisation and acidification, desertification, air- and water pollution, and withdrawal of land for housing, industry and transportation now destroy soils more rapidly than they can be formed.