Abstract
For the purpose of studing the effect of the roughness of ploughing and harrowing, upon the growth of the paddy rice a series of experiments were performed. The results were as follows : 1) The early growth of the rice plants, planted on roughly ploughed and harrowed paddy field, was worse than the growth of the plant growing on intensively ploughed and harrowed field. But at a later stage, the growth of the plant on the both fields becomes nearly equal. 2) The soil of the roughly ploughed field contained less NH3-N than the intensively ploughed field. Probably, this is the cause of the difference in the growth of the both fields. 3) The difference in growth of both fields can be controlled a little by the method of manuaring.
