Abstract:

The japonica super rice in North China ‘Shennong 265’ was used to study the tiller dynamics, the LAI dynamics, matter production characteristics, yield component characteristics and the effects of matter production characteristics on yield under four different nitrogen application patterns. The results showed that for each nitrogen application pattern, the yield under high nitrogen application (14.5 kg 667 m^-2) was significantly higher than that under low nitrogen level (12.5 kg 667 m^-2). On yield component, the high yields under high nitrogen application patterns lay in the increase of factors “outside panicles” (number of panicles, number of spikelet per square meter, filled grains per square meter) and the decrease of factors “inside panicles” (weight per panicle, 1 000-grain weight, seed setting rate, total number of grains per panicle, number of filled grains per panicle). On the same nitrogen application level, the yields of “Five-time application in three periods” (FTATP) pattern and “Stable application at early stage large application at middle stage and satisfied application at late stage” (SELMSL) pattern were significantly higher than those of “All application at early stage” (AAES) pattern and “Slow-release fertilizer applied once at early stage” (SRFAOES) pattern. But the yield components of FTATP and SELMSL were different. FTATP increased yield by improving factors “outside panicles”, while SELMSL reached high yield by improving factors “inside panicles”, The yields of FTATP and SELMSL were significantly higher than those of AAES and SRFAOES, which lay in the increase new assimilate after heading (assimilate supplying directly) and the secondary utilization of the matter accumulated in nutritorium before heading (assimilate supplying indirectly) under FTATP and SELMSL. And the matter output rate and contribution rate to the yield from nutritorium were higher than those under AAES and SRFAOES. Besides, with the two nitrogen application levels, FTATP and SELMSL had significantly higher Agronomic N use efficiency, Apparent N recovery efficiency, total N per square meter than the other patterns. Under 14.5 kg 667 m^-2 of nitrogen application, FTATP and SELMSL reached the super high yield (>11 t ha^-1).

Key words: Japonica super rice, Nitrogen application pattern, Super high yield, Matter production, Yield component