不同氮肥运筹方式对夏玉米产量和氮素利用的影响

以夏玉米杂交种郑单958为材料,对不同氮肥运筹方式下的夏玉米产量、产量构成、穗部性状、叶面积指数、干物质积累、穗位叶叶绿素相对含量以及光合速率、子粒形成的碳氮来源、收获指数、氮素收获指数及氮肥利用效率进行了研究。结果表明,在施总氮量相同的条件下,以播种期施氮结合大喇叭口期和抽丝期二次追施氮效果最好,即产量和氮肥利用效率均处于较高水平;其次为大喇叭口期一次追施氮;抽丝期一次追施氮以及前重后轻的施氮方式导致后期叶片缺肥早衰,影响光合产物的积累,从而影响产量,降低氮肥利用效率。

Effect of Nitrogen Supply Ways to Yield and Nitrogen Utilization in Summer Maize (Zea mays L)

Effect of nitrogen supply ways to yield and its components,ear characteristics,leaf area index,dry matter accumulation,SPAD and photosynthetic rate of ear-leaves,C and N from different sources in grain,harvest index,nitrogen harvest index and nitrogen utilization efficiency in summer maize Zhengdan 958 were studied in the field.The results show as follow: with the same total nitrogen quantity,supplying nitrogen at sowing,big trump and silking stage provides the highest yield and nitrogen utilization efficiency while supplying nitrogen at sowing and big trump stage provides the second.Supplying nitrogen at silking stage or supplying more nitrogen at sowing stage provide lower yield and nitrogen utilization efficiency as the leaves become old earlier with a lower photosynthetic rate in late growth stages.