Studies of Direct-Sowing Culture by Broadcasting Seeds on a Submarged Paddy Field : No. 7 Effects of seeding density and amount of top dressing on the yield of rice and its components

摘要

This expriment was done in 1965 in the same place and method as in the previous experiment (No. 6), using a variety of HOYOKU. The treatments of seeding density were 100, 150, 200 and 250 hills/m2. The amount of nitrogen in the. basic fertilizer applied was 9.6 g and the top dressed nitrogen levels were 1.5 g, 3.0 g, 4.5 g and 6.0 g. It was observed that the number of panicles was influenced by the basic fertilizer as well as the top dressing, and in each density treatment, the more top dressed, the more spikelets born and the weight of 1, 000 grains increased. As far as this experiment was concerned, the seeding density of 100-150 hills/m2 and the high levels of top dressing served to increase the grain yield comparatively.