Abstract
The writer's conclusions from his studies on this relation taking Tama Upland as his field, are as follow;-
(1) However complex are the factors to do with.soil erosion, soil factor is greater than other factors, in this region.
(2) The soils from pliocene series (St. 4) have suffered more losses than the Kanto loam soils.
(3) The soil erosion is much severer in cultivated fields (St. 2. 3. 4) than in woodlands.
(4) If the soils are porous, rain easily permeates into them, making them (St. 1. 2. 3) unstable in such a degree as to cause ruin-off and erosion.
(5) The dispersion, ratio is one of the good indicators which determine the resistability to running water. The dispersion ratio of the cultivated soilsespecially St. 4-is largerr than that of others.
(6) The silt dispersion ratio of soils is one of the indicators which determine the resistability against erosion. The larger this ratio, the more are soil particles which are unstable to running water., These soils (St. 4. 2) are more liable to transportation and hence. to erosion.
(7) Generally speaking, the loam soils are more resistant to erosion than soils from pliocene series.
