Abstract: Nitrogen (N) before transplanting, applied in seedling-bed and carried to the paddy field with seedlings is proposed in this paper. The effect of this method on tillering, N accumulation, N fertilizer utilization efficiency (NUE), and grain yield were investigated in a field experiment with a japonica cultivar Ningjing 2. The results indicated that, on the condition of equal basic and tillering N fertilizer, the tillers number in the treatment of nitrogen fertilizer applied before transplanting (N-100%) was 300 thousand ha-1 higher than that in treatment of no N fertilizer applied before transplanting (CK). At the critical stage of productive tiller, the tillers rate with leaf age >3 in N-100% treatment was remarkably higher than that in CK. Compared with CK, the rate of effective tillers, number of effective panicles, N accumulation, NUE, and grain yield of N-100% treatment were markedly increased. But the application of N was only 5.55 kg ha-1 more than that of CK. In N-75% treatment the application of N was 32.4 kg ha-1 lower than that in CK, while N accumulation and NUE were higher than those in CK. Compared with CK, N application of N-50% treatment was too lower, therefore it had negative effect on accelerating tiller’s development. As a result NUE and grain yield of N-50% treatment were observably lower than that of CK. The results suggested that proper N fertilizer applied before transplanting had positive effect on accelerating tiller’s development, and enhancing rate of effective tillers. Moreover, application of N fertilizer before transplanting could reduce the quantity of basic and tillering N fertilizer, speed absorption and utilization of N fertilizer, and increase N accumulation and NUE in rice.

Key words: Rice, Plastic-plate dotsow, Nitrogen fertilizer applied before transplanting, Nitrogen utilization efficiency, Yield