Christian Valentin

Soils as a Key Component of the Critical Zone 1. Functions and Services

Christian Valentin

This introductory book to the six volume series includes an introduction defining the critical zone for mankind that extends from tree canopy and the lower atmosphere to water table and unweathered rock. Soils play a crucial role through the functions and the services that they provide to mankind. The spatial and temporal variability of soils is represented by information systems whose importance, recent evolutions and increasingly performing applications in France and in the world must be underlined. The soil functions, discussed in this book, focus on the regulation of the water cycle, biophysicochemical cycles and the habitat role of biodiversity. The main services presented are those related to the provision of agricultural, fodder and forest products, energy, as well as materials and the role of soil as infrastructure support. They also include the different cultural dimensions of soils, their representations being often linked to myths and rites, as well as their values of environmental and archaeological records. Finally, the issue is raised of an off-ground world.

Soils as a Key Component of the Critical Zone 5. Degradation and Rehabilitation

Christian Valentin

One third of the world's soils have already been degraded. The burden on the land continues to grow under the combined pressures of demography, urbanization, artificialization and mining, and there are increased demands on agricultural land: changing dietary preferences, land speculation, as well as new demands for agroenergy, fiber, green chemistry, and more. Resulting issues such as soil crusting, water and wind erosion, soil salinization and soil acidity therefore constitute a major threat. The authors of this book present the main processes and factors of soil degradation, different ways to prevent it and methods of rehabilitation. The book also deals with the origin and processes of metallic and organic soil pollution as well as methods of phytoremediation and restoration. It is one of the few books to explore the issue of soil artificialization and urban soil management and to highlight how agricultural and urban waste can be used to amend and fertilize cultivated soils.