The Rate of vertical translocation of soil organic carbon fractions stored in buried humic horizon from an Andosol

Wijesinghe, J.*; Koarashi, Jun   ; Atarashi-Andoh, Mariko  ; Kokubu, Yoko   ; Yamaguchi, Noriko*; Sase, Takashi*; Hosono, Mamoru*; Inoue, Yuzuru*; Mori, Yuki*; Hiradate, Shuntaro*

The movement of soil organic carbon is important for understanding the formation and distribution of carbon in deeper soil layers. In the present study, we estimate the rate of vertical translocation of humin, humic acid, and four fulvic acid fractions and their relationship with chemical structure determined by CPMAS C NMR analysis. The average rates of vertical translocation of humin and humic acid were 4 and 5 mm per century, while those of fulvic acid were generally around 10 mm per century. C age of humic asid and humin in all layers was similar to the soil formation age, indicating that they have poorly translocated downwards. The young C age of some fulvic acid fractions in some layers indicates the translocation of young carbon from upper layers.