Part 1 Terminology, Concepts and Geographic Distribution of Volcanic Ash Soils: Terminology; Central concepts; Geographic distribution of volcanic ash soils. Part 2 Morphology of Volcanic Ash Soils: Morphological characteristics; Examples of profile morphology. Part 3 Genesis of Volcanic Ash Soils: Formation of Andisols; Transition of Andisols to other soil orders. Part 4 Classification of Volcanic Ash Soils: Classification of Andisols; Classification of Andisols in the FAO/Unesco Soil Map of the World; National classifications of volcanic ash soils. Part 5 Mineralogical Characteristics of Volcanic Ash Soils: Volcanic ash as a parent material; Colloidal constituents common to volcanic ash soils; Formation and transformation of colloidal constituents. Part 6 Chemical Characteristics of Volcanic Ash Soils: Inorganic constituents; Organic constituents; Metal humus complexes; Physico-chemical properties. Part 7 Physical Characteristics of Volcanic Ash Soils: Soil colour; 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. Part 8 Productivity and Utilization of Volcanic Ash Soils: Soil productivity; Chemical properties relating to soil productivity; Physical properties relating to soil productivity; Utilization and management of volcanic ash soils in Japan. Appendices: Description and selected properties of Tsukuba soil, Findley Lake soil, and Abashiri soil; Andisol TU database; Selected thermodynamic data and uncertainties used in modelling mineral stability relationships in Fig. 5.12; Reactions and equilibrium constants (25 degrees C) used modelling stability relationships in Fig. 5.12.