Plates. Preface. Acknowledgements. The Authors. 1. Terminology, Concepts and Geographic Distribution of Volcanic Ash Soils. Terminology. Central concepts. Geographic distribution of volcanic ash soils. 2. Morphology of Volcanic Ash Soils. Introduction. Morphological characteristics. Examples of profile morphology. 3. Genesis of Volcanic Ash Soils. Introduction. Formation of Andisols. Transition of Andisols to other soil orders. 4. Classification of Volcanic Ash Soils. Introduction. Classification of Andisols. Classification of Andisols in the FAO/Unesco Soil Map of the World. National classifications of volcanic ash soils. 5. Mineralogical Characteristics of Volcanic Ash Soils. Introduction. Volcanic ash as a parent material. Colloidal constituents common to volcanic ash soils. Formation and transformation of colloidal constituents. 6. Chemical Characteristics of Volcanic Ash Soils. Introduction. Inorganic constituents. Organic constituents. Metal humus complexes. Physico-chemical properties. 7. Physical Characteristics of Volcanic Ash Soils. Introduction. Soil color. Soil texture. Soil structure. Soil consistence. Bulk density and porosity. Water retention and plant available water. Water permeability. Irreversible changes in soil physical properties with drying. 8. Productivity and Utilization of Volcanic Ash Soils. Introduction. Soil productivity. Chemical properties relating to soil productivity. Physical properties relating to soil productivity. Utilization and management of volcanic ash soils in Japan. Appendix 1. Description and selected properties of Tsukuba soil, Findley Lake soil, Abashiri soil, and Yunodai soil. Appendix 2. Andisol TU database. Appendix 3. Selected thermodynamic data and uncertainties used in modeling mineral stability relationships in Fig. 5.12.