Abstract
1) The clay mineralogical composition of cultivated soils of Nagasaki Prefecture was grouped into the following 8 types according to previous analytical data : smectite, smectitic, chlorite/mica/vermiculite/intergrade (I), chlorite/mica/vermiculite/intergrade (II), kaolin mineral (I), kaolin mineral (II), allophanic and noncrystalline mineral-layersilicate minerals. 2) The mapping of these 8 clay mineralogical types was found to correspond well with the distribution of cultivated soils in Nagasaki Prefecture, suggesting the usefulness of the clay mineralogical map as soil information on a regional basis covering the whole prefecture. 3) The clay mineralogical map could be a good index for the evaluation of soil productivity, other than land suitability classification, from the close relationship between the clay mineralogical types and the cation exchange capacity and specific surface area of soils. 4) The clay mineralogical map was suggested to give available information on land-use planning, soil management, manuring practice, prevention of environmental pollution and prediction of landslide-prone areas, and some examples are shown.
