【摘要】 为了探讨氮肥施用量和施用方法对杂交稻产量和氮素利用效率的影响,2001~2003年在湖南省宁乡县回龙铺镇进行了大田栽培试验。结果表明:改进施氮处理的氮肥用量为100~120 kg/hm2,比农民习惯施肥减少38.9%~47.6%,产量增加0.48~1.48 t/hm2,增幅6.32%~27.3%,减氮增产的效果显著;获得最高产量的适宜氮肥用量为99~147.5 kg/hm2,成熟期氮素吸收量为146.9~194.3 kg/hm2。改进的施氮处理AEN平均为10.6~14.3 kg/kg,比农民习惯施肥增加7.0~10.7 kg/kg;PFPN平均为65.2~96.8 kg/kg,比农民的习惯施肥增加34.1~65.7 kg/kg;REN平均为68.5%~76.2%,比农民习惯施肥增加14.1%~21.8%,增幅均达到显著或极显著水平。分析了氮肥用量对植株干物质在茎秆、叶片和稻穗分配的影响,讨论了植株后期对氮素的奢侈吸收而导致减产的可能性。更多还原

【Abstract】 In order to explore the effects of nitrogen(N) rate and application methods on the yield and N use efficiency in hybrid rice,the field cultivation experiment was conducted in Huilongpu Town,Ningxiang County,Hunan Province in 2001~2003.The results showed that the N rate of modified N treatment(MNT) was 100~120 kg/hm2 which was reduced by 38.9%~47.6% compared with farmers’ practice.The yield of MNT was increased 0.48~1.48 t/hm2 and by 6.32%~27.3% compared with farmers’ practice.The effect of MNT on increase in yield and decrease in nitrogen was significant.As for highest yield,the optimum N rate was 99.0~147.5 kg/hm2 and the N uptake was 146.9~194.3 kg/hm2 at maturity stage.Compared with farmers’ practice,the average AEN of MNT was 10.6~14.3 kg/kgN and was increased by 7.0~10.7 kg/kgN,the average PFPN of MNTd was 65.2~96.8 kg/kg and was increased by 34.1~65.7 kg/kgN,and the average REN of MNT was 68.5%~76.2% and was increased by 14.1~21.8 percentage point.The increasing ranges reached to the significant level.This paper also analyzed the effects of N application rate on the dry matter distribution among stem,leaf and panicle,and discussed the possibility of the yield loss because of the excessive N uptake during the late growth period.更多还原