Studies on the Available Uses of Pan-Breakr (X IV)

Abstract

This paper repots the results of studies on the relations between the lasting effects of pan-breaking and the freezing action of soil, which were carried out on the 9th-10th of February, 1962, at Tokotan region in Konsen, Hokkaido. In the plots, the pan-breaking was practised in 1959 and 1960. The results are as follows;
1. In the untreated plots, the layer of the frozen soil seems to be formed thicker than in the treated plots. However, these tendencies were opposite to the results which were pointed out last year.
2. Generally in the treated plots, ice crystals are found at the lower layer in the frozen soil. However, in the untreated plots, they are found mainly at the middle or upper layer in the frozen soil.
3. In the double treated plots (60cm and 30cm depth), the tendencies of iu crystal formation are as follows. At the ordinary crop field, ice crystals are found mainly at the lower layer in the frozen soil, and furthermore the amount of iice crystals is little. However, at the pasture land, they are distributed to the overall layers of the frozen soil, and concentrations of ice are little.