抄録
Experimental studies were conducted through four years, from 1951 to 1954, at Tohoku Agr. Exp. Sta., Morioka Prefecture, on the influence of crops of 16 kinds on soil erosion on an experimental field with a slope of 10° and a slope length of 36 feet. 1. The soil loss in the plot without cover crops was 12, 872kg per Tan through four years. The cover-cropped plots was lower in erosion intensity, and there was observed a high correlation between the soil loss and the density of crop plant canopies. 2. Among the crop kinds studied, red clover was the highest in the soil conserving efficacy, while rape was the lowest, the order being as follows. red clover (in the second year) > sweet potato > turnip > soybean > cabbage > potato > sawa-millet > upland rice > oats > red clover (in the first year) > green cut corn > buckwheat > radish > corn > wheat > rape. 3. If we should consider the allowable soil loss 3 to 4 tons per acre per year, cropping continuously in furrows along the slope lines on a hill, which is usual manner of cropping practice in the majority of Tohoku District, would evidently be not favourable for soil conservation.
