施氮量对超高产夏玉米产量及氮素吸收利用的影响

选用登海661（DH661）和郑单958（ZD958）为试验材料，研究了超高产条件下施氮量对夏玉米产量、氮素利用及其转运规律的影响。结果表明，随着施氮量的增加，子粒产量、植株氮素总积累量和氮肥利用率呈先增加后降低。施氮量为N 240～360 kg/hm2，DH661和ZD958产量分别达12172～15080 和12011～15360 kg/hm2；而氮素利用率和氮肥农学利用率，DH661分别为10.6～23.1%和11.5～13.6%，ZD958分别为24.1～28.6%和9.5～11.4%；植株氮素总积累量和氮肥利用率均达到最大。施N 240～360 kg/hm2，提高了营养器官中氮素转运量和花后氮素同化量，可以有效调控开花前氮素转运及花后直接同化，促进子粒氮素积累，提高产量。在本试验条件下，施 N 240～360 kg/hm2可提高氮肥利用率，实现玉米高产。

Effects of nitrogen application on yield and nitrogen use efficiency of summer maize under super-high yield conditions

The effects of nitrogen application rates on grain yield,nitrogen translocation and use efficiency under super-high yield conditions were studied in fields.Two cultivars of summer maize(Zea mays L.),Denghai 661(DH661) and Zhengdan 958(ZD958) were selected as experimental materials.The results show that the grain yield,amount of total nitrogen accumulation in plant and nitrogen recovery efficiency are increased at first,and then decreased with the increase of nitrogen application rates.The grain yields of DH...