Existing State and Forming Environment of Humic Acid Pg Fraction in Tephra Soil Sequence of Southern Kyushu, Japan

摘要

Pg fraction of humic acid is one of the com- ponents of humic substances extracted from soils and terrestrial sediments; it is charac- terized by the presence of green pigment. This green pigment derives from metabol- ites of many species of fungi and is widely distributed in world soils. In this paper, the vertical distribution of Pg absorption strength was obtained for the tephra soil sequence con- sisting of 6 representative tephras in southern Kyushu.