针对当前东北地区玉米种植密度偏低、氮肥管理粗放及应用传统氮肥诊断方法存在的限制与不足等问题，以协同玉米增产与氮肥高效为目标，在黑龙江省哈尔滨市开展田间试验，设置2个种植密度、2个玉米品种和6个氮水平小区试验，应用新式主动冠层传感器GreenSeeker，于玉米V5～V10期动态取样监测，建立回归模型，分析增密种植条件下不同玉米品种氮营养诊断指标变化，探究种植密度与品种对主动冠层传感器实时氮营养指标估测模型的影响。结果表明，适量施氮有利于改善植株氮营养状况、促进玉米增产;氮、密互作共同影响籽粒产量，种植密度由D6增至D8，籽粒产量与施氮量线性平台拐点由196。0、200。4 kg N·hm-2分别增加至208。8、209。4 kg N·hm-2;氮浓度稀释曲线Y=34。0X-0。37在黑龙江地区适用，氮营养指数(Nitrogen nutrition index，NNI)诊断阈值主要受种植密度影响;GreenSeeker植被指数(Normalized difference vegetation index，NDVI)与地上部生物量、植株吸氮量、叶面积指数相关性较好，决定系数达0。75～0。89;NNI与NDVI相关模型决定系数较低，仅为0。49～0。58;NDVI对植株氮浓度诊断结果不佳。NDVI可用来准确诊断玉米氮营养状况，但需综合考虑氮肥用量、密度与品种耐密性对诊断模型准确性的影响。研究将GreenSeeker传感器最新诊断技术引入玉米增密群体氮营养诊断，评估氮浓度稀释曲线适用性，相关结果可为玉米增密群体的氮精准管理提供理论依据，未来具备区域大面积应用潜力。
Non-destructive monitoring of spring maize (Zea mays L.) nitrogen status indicators using active optical sensor GreenSeeker under increasing planting density
Addressing the issues of low planting density and crude nitrogen fertilizer management in maize cultivation in Northeast China,this study aimed to synergize maize yield increase with nitrogen fertilizer efficiency. Field experiments were conducted consecutively in Harbin City,Heilongjiang Province,with two planting densities,two maize cultivars and six nitrogen levels. A novel active canopy sensor,GreenSeeker,was utilized for dynamic sampling and monitoring during the maize growth stages (V5-V10). Build a regression model to analyze the variation in nitrogen diagnostic indicators of different maize varieties under increased planting density. Furthermore,the impact of planting density and cultivar on the estimation model of real-time nitrogen nutrition indicators by the GreenSeeker active canopy sensor was investigated. The results showed that moderate nitrogen application improved plant nitrogen nutrition and promoted maize yield. Nitrogen and planting density interacted to affect grain yield. As planting density increased from D6 to D8,the linear plateau turning point of grain yield with nitrogen application shifted from 196.0 kg N per hectare to 208.8 kg N per hectare and from 200.4 kg N per hectare to 209.4 kg N per hectare,respectively. The nitrogen dilution curve Y=34.0X-0.37 was applicable in the Heilongjiang region,with the nitrogen nutrition index (NNI) diagnostic threshold mainly influenced by planting density. The GreenSeeker vegetation index (NDVI) showed good correlation with aboveground biomass,plant nitrogen uptake and leaf area index,with coefficients of determination ranging from 0.75 to 0.89. However,the correlation model between NNI and NDVI had a lower coefficient of determination,ranging from 0.49 to 0.58,and NDVI performed poorly in diagnosing plant nitrogen concentration. In concluding,the GreenSeeker vegetation index NDVI could accurately diagnose maize nitrogen nutrition status but required comprehensive consideration of the effects of nitrogen fertilizer dosage,density and variety tolerance on the accuracy of the diagnostic model. This study introduced the latest GreenSeeker sensor diagnostic technology into nitrogen nutrition diagnosis for intensively cultivated maize populations and evaluated the applicability of the nitrogen dilution curve. The results provided theoretical basis for precise nitrogen management in maize intensification and had the potential for large-scale application in the future.
plant densitycultivarGreenSeekernon-destructive N diagnosismaize
万方数据
维普
