优化氮素与品种匹配可协同提高盐碱地夏玉米产量和氮肥利用率

【目的】 明确不同耐盐碱型夏玉米品种产量形成及氮素利用特征,挖掘盐碱地玉米氮素高效利用的生物学潜力。【方法】 以耐盐型玉米品种登海605、鲁单818和不耐盐型玉米品种鲁单981、连胜188为供试材料,在不同施氮水平下（0、180和360 kg·hm^-2,记作N0、N1和N2）,系统研究了施氮对不同耐盐碱类型玉米品种物质积累、氮素积累、氮素分配与利用效率及产量形成的影响,并分析了氮肥水平和品种间的互作效应。【结果】施用氮肥可显著提高盐碱地夏玉米籽粒产量,高氮水平下能够提高不耐盐型玉米品种产量潜力。与N1处理相比,N2处理下耐盐型玉米品种产量无显著变化,不耐盐品种LD981和LS188 2年平均显著增产9.93%和16.31%,各品种氮肥偏生产力（NPFP）、氮肥农学效率（NAE）和氮肥利用率（NUE）均显著降低。互作效应分析表明,产量及其构成因素的差异是由品种、氮肥水平及品种和氮肥水平之间的互作效应共同作用的结果。不同氮肥水平下,耐盐型品种比不耐盐品种分别增产7.78%—27.63%（N0）、7.40%—24.87%（N1）和0.32%—9.55%（N2）;氮肥利用效率（NUE）分别提高26.65%—48.28%（N1）和1.20%—24.87%（N2）。【结论】耐盐型品种较不耐盐型品种具有较高的物质生产和氮素吸收利用能力,在低氮下具有较高的产量优势,而不耐盐型品种在高氮水平下有利于产量的发挥。施氮量、品种及其互作效应通过影响干物质积累量、产量和氮素吸收转运影响氮肥利用效率,优化氮肥供应与品种匹配,能够实现盐碱地玉米产量与氮肥利用效率的协同提高。

The Coordination of Nitrogen Optimization with Matched Variety Could Enhance Maize Grain Yield and Nitrogen Use Efficiency of Summer Maize in Saline Land

【Objective】In order to achieve synergistic promotion of both maize grain yield and nitrogen use efficiency (NUE) under salt stress, it is essential to explore the performance difference of different salt-tolerant maize varieties on yield formation, nitrogen uptake, transport and utilization, to excavate biological potential of maize varieties using nitrogen, so as to provide matched maize variety for the optimized nitrogen application regime.【Method】In this study, salt-tolerance maize varieties Denghai605, Ludan818 and salt-sensitive maize varieties Ludan981 and Liansheng188 were separately used to systematically study the effects on accumulation and distribution of dry matter and nitrogen, nitrogen utilization efficiency and yield formation under different nitrogen application rates of 0, 180 and 360 kg·hm^-2, denoted by N0, N1 and N2 treatments in turn, as well as the interaction of nitrogen levels and maize varieties and inter-annual were analyzed.【Result】Suitable nitrogen application rate could significantly increase grain yield. Compared with N1 treatment, there were no difference in grain yield for salt-tolerance varieties but significant increase for Ludan981 (avg. 9.93%) and Liansheng188 (avg. 16.31%) under N2 treatment. Also, high nitrogen application (N2) got lower nitrogen agricultural efficiency (NAE), nitrogen utilization efficiency (NUE) and nitrogen partial factor productivity (NPFP) than low nitrogen application (N1). The difference in grain yield and yield components was the result from the varieties, nitrogen regimes, and their interaction. Compared with salt-sensitive maize varieties, salt-tolerance maize varieties had greater grain yield, nitrogen absorption and use efficiency across same nitrogen regime. Specifically, the grain yield of salt-tolerance maize varieties were increased by 7.78%-27.63% (N0), 7.40%-24.87% (N1), and 0.32%-9.55% (N2), respectively, while the nitrogen utilization efficiency were increased by 26.65%-48.28% (N1) and 1.20%-24.87% (N2), respectively.【Conclusion】It was performance well for the salt-tolerances varieties than the salt-sensitive varieties on dry matter accumulation and nitrogen uptake and utilization. Low nitrogen application was beneficial for salt-tolerant maize variety getting higher grain yield and vice versa. The nitrogen utilization efficiency was affected by maize varieties, nitrogen regimes and its interaction, through affecting grain yield, dry matter accumulation, and nitrogen uptake and utilization. Thus, it would be an efficient strategy to achieve synergistic promotion of both maize grain yield and nitrogen use efficiency, through the coordination of nitrogen optimization with matched maize variety.