Field experiments were conducted in double cropping rice field to study the effects of nitrogen fertilizer rates (0,120,180,240 kg/hm2)on yield and N-uptake and use efficiency of no-tillage cast transplanting rice. The results showed that the grain yield of no-tillage and cast transplanted rice increased significantly with the nitrogen application from 0 to 240 kg/hm2, with the amount of N application in excess of 180 kg/hm , the late rice grain yield decreased significantly. There was a significant positive correlation between the amounts of N application and N accumulation; there was a significantly positive correlation between the N transfer efficiency from heading to maturity stage and grain yield. The fertilizer-N recovery efficiency of no-tillage cast transplanted early rice increased with the increase of the amounts of nitrogen application, but that of no-tillage and cast transplanted late rice decreased with the amounts of nitrogen application; the fertilizer-N physiological efficiency and agronomic efficiency and N-harvest index decreased with the increase of the amounts of nitrogen application.%研究了双季稻免耕抛栽氮肥用量(0,120,180,240 kg/hm2)对产量及氮素吸收利用的影响.结果表明,在0 ～ 240 kg/hm2供氮水平下,免耕抛栽稻产量随氮肥用量的增加而显著增加,当氮肥用量超过180 kg/hm2,晚稻产量显著下降.水稻一生中氮素的积累量与施氮量呈显著正相关,早、晚稻抽穗至成熟期茎叶氮素的运转率与产量呈显著正相关.氮肥的吸收利用率免耕抛栽早稻随着施氮量的增加而增加,晚稻则随施氮量的增加而降低；氮肥的生理利用率、农学利用率和氮收获指数均随施氮量的增加而降低.
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