Use of soil database for pedological research on volcanic ash soils

A soil database is a digital storehouse of soil information and it is expected to be useful for many purposes. Several examples to use soil databases for pedological studies on volcanic ash soils were introduced. The soil databases we used are, the soil database of Ando soils in Japan (ASJ), the soil database of Andosols from northern part of circum-pacific volcanic zone (ATUD), the soil database of Andosols from volcanic areas in the world (TUWAD), the soil database of cultivated soils in Japan collected during 1959-1978 (DBOD), data of soil monolith in NIAES used for determination of elemental concentration (DSMN) and water quality data of rivers in Japan (WQRJ). These data sets have been stored as spreadsheet files and it is easy to use them. For examining criteria to define andic and vitric properties of World Reference Base for soil resources, TUWAD was used. The DBOD was used to elucidate involvement of exchangeable Ca and Mg in phosphate sorption coefficient. The ASJ was used to illustrate depletion of Si, Ca and Na, and enrichment of Al, Fe and other immobile minor elements during Andosol formation. These results were confirmed using DSMN. The ATUD was used to describe chemical and physical characteristics of Andosols. As shown in these examples, the soil databases are useful to test soil classification criteria, to examine relationship between a new experimental results and previously reported data, etc. It is desirable to construct a soil database that covers wide regions and research areas in the future