抄録
Minerals are the major and characteristic constituents of many soil horizons and soils. Twelve essential nutrient elements are provided from the minerals although nitrogen is provided from soil organic matter including organisms. Four following topics about minerals in volcanic ash soils and paddy field soils were introduced and the perspectives on future research were discussed. (1) During andosolization, Al, Fe, Ti, Sc, rare earth elements, etc., are concentrated as nearly immobile elements in accordance with the removal of Si, Ca, Na, etc. (2) Apatite in volcanic ash is sparingly soluble around neutral pH, and acid or chelating organic acid exudation is effective for plants to uptake P from apatite. (3) Biotite in volcanic ash can be easily weathered to vermiculite releasing K^+ that is one of the major essential elements for plants. (4) Vivianite was found on rice roots grown in lowland soils.
