Origin of the soil texture classification system used in Japan

Abstract

The classification systems for soil particle size ranges and soil texture differ among countries and/or associations. Unique systems have also endured in Japan over the last six decades. However, the original reports explaining the rationale for these systems have gradually been lost, so there is no source written in either Japanese or English for authors to reference the origin of the Japanese soil classification systems. In this light, we reviewed the origin of the Japanese classification systems for soil particle size ranges and soil texture. The size range system was adopted from International Society of Soil Science (ISSS) standards. The soil texture classification system was introduced by Tommerup in his paper at the ISSS Commission I (Soil Physics) meeting in 1934. This soil texture classification system was modified by Yamanaka in 1955, and was henceforth adopted as the conventional soil texture classification system in Japan. This ISSS-defined soil texture classification system has been in use since that time.