Soils as a Key Component of the Critical Zone 5: Degradation and Rehabilitation (Geosciences Series: Soils Set)

"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."--Back cover Content: Cover Half-Title Page Title Page Copyright Page Contents Foreword 1. The State and Future of Soils 1.1. Soils as a key component of the critical zone 1.1.1. Definitions 1.1.2. Soil functions and services 1.1.3. Soil and land degradation, desertification 1.2. The difficult assessment of the state and kinetics of soil degradation or enhancement 1.2.1. Global assessment 1.2.2. Forms of degradation 1.2.3. Main factors of soil degradation 1.2.4. What's the trend: degradation spiral or U-curve? 1.2.5. The necessity for monitoring mechanisms 1.3. Conservation, restoration, rehabilitation and compensation1.3.1. Definitions 1.3.2. Implementation 1.3.3. Concept of neutrality in terms of land degradation 1.4. Conclusions 1.5. References 2. Soil Surface Crusting of Soiland Water Harvesting 2.1. Surface conditions and surface crusts 2.2. Crust types and formation processes 2.2.1. Structural crusts 2.2.2. Gravel crusts 2.2.3. Erosion crusts 2.2.4. Depositional crusts 2.2.5. Saline crusts and efflorescence 2.2.6. Biological soil crusts (or Biocrusts) 2.3. Crusting factors and principles for improving aggregate stability 2.3.1. Soils2.3.2. Rain 2.3.3. Slope 2.3.4. Cover 2.3.5. Agricultural practices 2.4. Consequences of surface crusting 2.4.1. Hydrological: Hortonian flow 2.4.2. Ecological: example of the tiger bush 2.4.3. Agronomic: water harvesting 2.5. Conclusions 2.6. References 3. Erosion and Principles of Soil Conservation 3.1. Definitions 3.2. The importance of erosion 3.2.1. On a global scale 3.2.2. Effects of erosion 3.3. Processes and factors 3.3.1. Splash detachment 3.3.2. Sheet erosion (also called inter-rill erosion) 3.3.3. Linear erosion 3.3.4. Mass movements 3.3.5. Tillage erosion3.3.6. Wind erosion 3.4. Erosion: a question of scale 3.4.1. Space scales 3.4.2. Time scales 3.4.3. Space scales 3.4.4. Particulate and soluble transport 3.4.5. Aeolian dust 3.5. Modeling 3.5.1. Statistical approaches 3.5.2. Physically based models 3.5.3. Hybrid models 3.6. Principles of soil conservation 3.6.1. Field level: limiting detachment 3.6.2. Catchment scale: slowing runoff and promoting deposition 3.7. Population density, economic contexts and public policies 3.8. Conclusions 3.9. References 4. Soil Acidity and Acidification 4.1. Acidity 4.2. Definitions of acidification and its evolution4.3. Illustration: long-term theoretical evolution of the acidity of a limestone loess 4.4. Acidifying processes 4.5. Involvement of large biogeochemical cycles in soil acidification 4.5.1. Nitrogen cycle 4.5.2. Carbon cycle 4.5.3. Absorption of cations/anions by plants 4.5.4. Acid or alkaline deposits 4.5.5. Other cycles: P, S, Fe, Mn 4.6. Neutralization of acidification 4.7. Biogeography of acidity 4.8. Physical and biological consequences of soil acidity 4.9. References 5. Soil Salinization andManagement of Salty Soils