Volcanic ash soils: genesis, properties and utilization

A comprehensive synthesis of all aspects of these soils, largely from the perspective of the middle latitudes and other temperate regions, is presented. There are sections on: terminology, concepts and geographic distribution; morphology, with examples of profile morphology; genesis, formation and transition to other soil types; the development of the classification of Andisols, as well as national systems used in Japan and New Zealand; mineralogical characteristics, including volcanic ash as a parent material and the formation and transformation of colloidal constituents; chemical characteristics, including organic and inorganic constituents, metal humus complexes and physio-chemical properties; physical characteristics, such as soil colour, texture, structure, consistence, bulk density and porosity, hydraulic properties and irreversible changes with drying; and chemical and physical properties relating to soil productivity and utilisation, with an assessment of utilisation and management in Japan. Data in the form of tables, figures and appendices, mainly from the Tohoku University Andisol Data Base, are used to illustrate major concepts. -J.W.Cooper