土壌の温度処理とカリ固定の関係

We usually combust the soil to take away the humus in the soil.
In the case of such a treatment of the soil, we observed the phenomenon in which the exchange sites of the inorganic substances of the soil may be changed. To study it more conclusively, we adopted this experiment.
Now, we treated two kinds of the soils under the various temperatures, that is, 100℃, 300℃, 500℃ and 700℃, and then in addition to this experiments, we observed how the K-fixation may be changed by the various hours, that is, 5 hours, 10 hours, 20 hours, under the same condition of the temperature.
The exchangeable K and the fixed K of the soils treated under 100℃ did not almost differ from those of the untreated soils. Then, we could observe that their differences between the treatments of the long hours and those of the short hours, under the 100℃, did not exist.
In the case of the soils treated under 300℃, the exchangeable K decreased with time, in comparison to the soils treated under 100℃. On the other hand, under the treatments of 5 hours, the fixed K did not almost differ from those of the soils of each treatment at 100℃, while it decreased with time.
Under the treatments at 500℃, the exchangeable K decreased with time, in comparison to the soils of each treatment at 300℃. The fixed K decreased, in comparison to the soils of each treatment at 300℃, and we did not recognize its differences among the soils treated at the fomerly cited hours.
Keeping the soils under 700℃, we recognized the exchangeable K decreased, in comparison to the soils treated at 500℃, but we could not observe the influence of time to exchangeable K. The fixed K were almost equal to those of the soils of each treatment at 500℃ and also we did not recognize the influence of time to the fixed K.