稻-油熟制下不同施氮量对杂交水稻群体构成及产量的影响

为中低肥力的稻-油熟制稻田的氮肥运筹提供参考,利用杂交稻品种Ⅱ优7号、渝香203在稻-油熟制的中低产田进行不同施氮量对杂交水稻群体构成及产量的影响试验。结果表明,施氮量在0～150kg/hm2水平范围,随着施氮量的增加,杂交水稻品种的产量均逐渐增加,再增加施氮肥时产量表现为下降的趋势,施氮量在150kg/hm2水平时产量最高,农学利用效率(AE)最经济;施氮量对群体的影响表现为:随着施氮量的增加,群体叶面积指数(LAI)增大,群体LAI值在7左右时,容易形成高产;成穗率随着施氮量的增加而降低,施氮量为210kg/hm2时成穗率最低。

Effects of Nitrogen Application on Hybrid Rice Population and Yield Composition in Rice-rape Seed Cropping System

Two hybrid rice varieties,IIYou 7 and Yuxiang 203,were tested in rice field with mid-low fertility under different nitrogen application level to study the effects on population composition and yield of hybrid rice varieties and provide a reference for rational nitrogen application in production of hybrid rice.The results showed that the yield of two tested varieties gradually increased with nitrogen increment within 0~150 kg/hm2 nitrogen level,but the yield presented a decline trend when nitrogen level was over150 kg/hm2.The yield and AE reached the highest when nitrogen level was 150 kg/hm2.The leaf area index of two tested rice varieties increased with increment of nitrogen level at heading stage.The high yield of two tested rice varieties could be obtained when the leaf area index of the rice population reached 7.The effective spike rate presented a decline trend with increment of nitrogen level and the effective spike rate was the lowest when nitrogen level was 210 kg/hm2.