关键词: 春玉米, 临界氮浓度稀释曲线, 氮营养指数, 氮营养诊断, 东北地区

Abstract: Excessive nitrogen fertilizer application is a common phenomenon in maize cultivation. Nitrogen nutrition index (NNI) based on the critical nitrogen dilution curves is an important means to diagnose nitrogen deficiency. This study collected and analyzed the data of four experiment site under different N application rates in Northeast China and developed critical nitrogen dilution curve. And on this basis, the nitrogen nutrition index model and nitrogen demand model were established. The results showed that there was a negative power function between aboveground biomass and critical N concentration in Northeast China. The critical nitrogen dilution curves were validated using other independent data. The results showed that the nitrogen nutrition index model could be used for accurating diagnosis of maize nitrogen status and nitrogen demand calculation. The critical nitrogen dilution curve of spring maize in Northeast China developed in this study  provided better theoretical and technical guidance for nitrogen diagnosis and dynamic regulation of spring maize in this region.

Key words: spring maize, critical nitrogen concentration dilution curve, nitrogen nutrition index, nitrogen nutrition diagnose, northeast China