Studies on the Improvement of the "Uwaba" Basalt Soil at the Drg Field.

Abstract

The result obtained are as follows : 1.The principalcause of low productiveness of the "Uwaba" basalt dry field were higher acidity, CaO and P_2O_5 deficiency. 2. The influence of P_2O_5 on the sweet potato were effectly farther than CaO. 3. When P_2O_5 and CaO were added sufficiently to the soil, the naked barley (Hordeum sativum, Jess. var. hexa stihon, Hack) grew normal and ripend complete. 4. When the one of P_2O_5 and CaO did not added to the soil, the length of leaves and stems became very shorter, and could not ripened.