不同种植密度下施氮对夏玉米物质生产及穗粒形成的影响

Effect of Nitrogen Application to Dry Matter Productivity and Kernel Setting in Summer Maize(Zea mays L) in Different Plant Populations

采用大田试验和室内生化分析等方法研究了不同种植密度下施氮对夏玉米物质生产和穗粒形成的影响。结果表明,在中(67 500株/hm2)、高(82 500株/hm2)密度下,氮肥对玉米单株物质生产能力的调控作用更为明显,并主要是通过影响穗粒数来实现的。适宜的施氮量可以使玉米叶片维持较高的光合性能,从而为穗粒形成提供充足的光合碳量。供氮不足或过量都导致生育后期叶片衰老加快。

Effect of nitrogen（N） application to dry matter productivity and kernel setting in summer maize （Zea mays L） hybrid Zhengdan 958 in different plant populations was studied through field experiment and biochemical analysis. The results showed that the effect of N to grain yield of individual plants, mainly acted through the regulation of kernel number, was more evident in 67 500 plants/hm^2 and 82 500 plants,/hm^2. Appropriate N could keep leaves a higher photosynthesis ability and provide more assimilate to grain, while both inadequate and excessive N accelerated the decreasing process of leaves at later growth stage.