Abstract
The critical growth stages of crop platnts for soil erosion in the cropping systems ordinary in Tohoku District were investigated by the data from erosion control experiments considered together with the rainfall characteristics observed at Tohoku Agr. Exp. Sta. in Morioka. It was found that the critical stages for erosion corresponded generally to the periods when the ground-cover furnished by plant stands is vulnerable in the course of cropping system coinciding with the periods of excessive rainfall.
