徐麦35高产高效增密减氮途径及其碳氮代谢调控机制

为探究增密减氮栽培途径的可行性及其碳氮代谢调控机制，于2019-2020年以徐麦35为材料，设置不同密肥组合，研究增密减氮对产量和氮效率的调控作用。结果表明，适当减少施氮量，徐麦35的氮素农学效率（NAE）、氮肥偏生产力(PFP)、氮素生理效率（PE）、氮收获指数（NHI）均显著增加。开花期和成熟期的碳氮比（C/N）与产量、NAE、PFP、PE均呈显著正相关。密度240×10·hm^-2~300×10·hm^-2、施氮量180 kg·hm^-2时产量可达到8 500 kg·hm^-2以上，高于180×10·hm^-2和270 kg·hm^-2密肥组合下的产量水平。同时，NAE、PFP、氮肥吸收效率（RE）、和PE分别提高了62.1%~67.9%、57.6%~59.1%、5.1%~14.4%和41.6%~59.4%。返青期施用控释肥（A₁）较拔节期施用尿素(A₂)的氮肥吸收效率平均提高了6.8%，有利于实现江苏淮北麦区节本增效绿色轻简化栽培。

Methods of High Yield and High Efficiency by Density Increase and Nitrogen Reduction in Xumai 35 and Its Regulation Mechanism of Carbon and Nitrogen Metabolism

In order to explore the feasibility of planting methods by increasing density and reducing nitrogen and the regulation mechanism of carbon and nitrogen metabolism,Xumai 35 was used as material in 2019-2020 to study their regulation effect on yield and nitrogen use efficiency. The results showed that the nitrogen agronomic efficiency(NAE),partial nitrogen productivity(PFP),nitrogen physiological efficiency(PE) and nitrogen harvest index(NHI) of Xumai 35 increased significantly with the decrease of nitrogen application rate. The ratio of carbon to nitrogen(C/N) at flowering and maturity stages was significantly positively correlated with yield,NAE,PFP and PE. When the density was 240×10·hm^-2-300×10·hm^-2 and the nitrogen application rate was 180 kg·hm^-2,the yield achieved more than 8 500 kg·hm^-2,which was higher than that under 180×10·hm^-2 for planting density and 270 kg·hm^-2 for nitrogen rate. Meanwhile,NAE,PFP,nitrogen absorption efficiency and PE increased by 62.1%-67.9%,57.6%-59.1%,5.1%-14.4% and 41.6%-59.4%,respectively. The nitrogen absorption efficiency under slow-release fertilizer(A₁) at re-greening stage was 6.8% higher than that under urea(A₂) at the jointing stage,which was conducive to the realization of cost saving,efficiency increasing,and eco-friendly cultivation in Huaibei region of Jiangsu province.