On the Tea Soil of Makinohara Plateau, Shizuoka Prefecture

Abstract

The classification and characteristics of tea soil on Makinohara Plateau, Shizuoka prefecture were researched.The soils of Makinohara plateau were consisted of two categories called "Akatsuchi" and "Kuroboku".From the results of morphological, mechanical and chemical analyses, these soils may be classified as follows1. "Akatsuchi" was classified as yellow soil.2. "Kuroboku" was considered to be deriv-ed from volcanic ash soil and designated as "Ando soil" on the soil survey U.S.A.The most conspicuous characteristics of these tea soils were as follows:1. From the results of mechanical analysis, the clay leached layers were observed in. the tea soil profile.2. The SiO2/Al2O3 of clay fraction of tea soil was generally high in the surface soil and which seemed to show. evidences of the translocation of the free R2O3 from the surface soil.3. Reaction of the tea soil was very strongly acidic, owing to heavy leaching of exchangeable calcium.4. Aluminium content soluble in neutral salt solutions or mineral acids was larger in the tea soil than in the cultivated soil, but that soluble in acetic acid was much in thecultivated soil.5. From these results, the tea soils seemed to have the characteristics of both forest soils and planosols.