1956 Volume 26 Issue 12 Pages 489-492
The relationships between free oxides and total oxides in the profiles of dry rice fields in polder lands of the Kojima-basin, Okayama pref. are reported. The distributions of free oxides in these soils were set forth in the previous report. The amounts of total oxides were determined by the HF-treatment, as Fig. 1. The differences between the amount of total oxide and that of free oxide and the ratios of free oxide in each soil were calculated as to iron & manganese, as illustrated in Fig. 2. Next, the amounts of free oxide were compared with that of total oxide, in furrow slice of each soil, as given in Table 2. Ratios of the amounts of free oxides in the maximum accumulation horizon to those in furrow slice were calculated, as given in Table 3.
