抄録
1) In this study, Intended to clear the effect of ground water level upon the growth of rape plant. 2) In this experiment, I made the ground water level of each plots as follows; 9cm, 15cm, 21cm, under the surface of ridge and the control. 3) In productivity and various characters those seem to be the factors of productivity, there were remarkable differences between 9cm plot and the other plots, but among 15cm plot, 21cm plot, and the contorol plot, there is no difference. 4.) By the root-system in the control plot, the roots of rape lie very densely in the part from surface of ridge to 15cm under, and there are few in deeper part. 5) Judging from the root-system, it will be fact that in 9cm plot, all of the roots are in the condition of flooding, but in the other plots a great part of roots are saved from the condidtion of flooding. It is seems that this condition of roots is the fundamental cause of the difference between 9cm plot and the other plots.
