ニ三の砂防植裁地における花崗岩土壌の風化について

1. In this paper the writer studied a weathering process of the soils derived from granite in Rokko, Kurita and Ueno district where the Sabo works (erosion control works) were carried.
2. No remarkable changes occur in the Feldspar/Quartz value of the fine sand fraction separated from the soils on which the Sabo-afforesting works were carried many years ago (about 60 years ago) and that of recently.
In Rokko District, especially, there was no difference between the value of the soils on which the Sabo works were carried recently and that of the natural stand.
3. Microscopic observation of the soils shows that chemical weathering of plagioclase in the soils of the old Sabo-planting forests and natural stands leads to kaolinization except in Rokko Soils.
4 . Microscopic observation of the Rokko Soils indicated that in this district disintegration seemed to be more favored than decomposition.