氮肥底追比例及施硫对小麦氮素吸收利用的调控

为明确氮肥底追比例与施硫间的互作效应,采用盆栽方式,以京冬8号和济麦20为供试材料,设置氮肥底追比例为3∶7(N_1)、5∶5(N_2)和7∶3(N_3)3个处理水平,每个底追比例下设置2个硫肥施用量:0kg·hm~(-2)(S0)和45kg·hm~(-2)(S_1),运用15N示踪技术研究开花期、成熟期营养器官及籽粒中氮素积累、分配以及对不同来源氮素利用的情况,同时对花后营养器官贮藏氮素的转运、对籽粒的贡献率及氮素利用效率进行分析比较。结果表明,2个小麦品种植株中积累氮素主要来自肥料氮,京冬8号成熟期来自肥料氮的积累量达60%~70%,而济麦20则达70%~80%。氮肥底追比例及硫肥互作对2个品种氮素吸收、转运和分配的影响存在差异,其中京冬8号成熟期籽粒氮素积累量、营养器官贮藏氮素花后的转运量、转运率、对籽粒的贡献率、籽粒产量以及氮肥的利用效率均在N_1S_0时较高;济麦20营养器官贮藏氮素花后的转运量、转运率、对籽粒的贡献率在N1S0时较高,而在N3S1时,成熟期籽粒氮素积累量、籽粒产量、氮肥的利用效率均较高。综上所述,本试验栽培环境下,氮肥底追比例为N1时能够提高花前贮藏氮素的转运量、转运率、对籽粒的贡献率、籽粒蛋白质含量及氮素收获指数;氮肥底追比例为N3时有利于提高籽粒产量、氮肥生产效率。综合考虑籽粒产量、氮肥生产效率、氮肥利用效率和氮素收获指数,京冬8号最优肥料组合为N_1S_0,济麦20最优肥料组合为N_3S_1。本研究结果为冬小麦大田生产中合理的肥料运筹提供了理论参考。

Effect of Nitrogen Fertilizer Ratio of Base and Topdressing and Sulfur on Nitrogen Absorption and Utilization in Wheat

Reasonable sulfur rate and nitrogen fertilizer ratio of base and topdressing can adjust the nitrogen absorption and translocation,which can provide the theory basis of nitrogen application.A pot experiment and 15N tracer technique were carried out to study the effect of sulfur rate and nitrogen fertilizer ratio of base and topdressing on nitrogen accumulation and its proportion from different sources at anthesis and maturity,and analyze their difference of absorption and transport of nitrogen,nitrogen fertilizer productive efficiency in Jingdong8 and Jimai20.There were three nitrogen fertilizer ratio of base and topdressing including 3∶ 7,5∶5 and 7∶ 3,which were marked N1,N2 and N3,respectively.And two sulfur rate were designed at 0 and 45 kg·ha-1,which were marked S0 and S1,respectively.The results showed that nitrogen from fertilizer were the main source in two cultivar,and the proportion were 60％ ～70％ for Jingdong8 and 70％ ～80％ for Jimai20.There were differences in nitrogen absorption and transport of two cultivar under different sulfur rate and nitrogen fertilizer ratio of base and topdressing.For Jingdong8,nitrogen accumulation in grain at maturity,nitrogen translation from vegetative organs to grain,grain yield and nitrogen use efficiency were higher in the treatment of N1S0 than other treatments.For Jimai20,nitrogen accumulation in grain at maturity,grain yield and nitrogen use efficiency were higher in the treatment at N3S1,but nitrogen translation from vegetative organs to grain were higher at the treatment N1S0 than other treatments.To sum up,when the nitrogen fertilizer ratio of base and topdressing was 3∶ 7,the nitrogen translation from vegetative organs to grain,protein content and nitrogen recovery index were the highest,and the grain yield and nitrogen productive efficiency were the highest in 7∶ 3.The most suitable fertilizer treatment of increasing yield,NPE and NUE for Jingdong8 was N1S0,but N3S1 for Jimai20.These findings provide a theoretical reference for reasonable fertilizer in winter wheat field production management.