Abstract: This study analyzed the changes of dry matter accumulation in different organs of maize under field conditions,using 4 treatments of N1 （0）,N2 （90 kg/hm²）,N3 （120 kg/hm²）,and N4 （150 kg/hm²）.The results showed that dry matter accumulation of leaves increased proportionally with the nitrogen fertilizer application from the grouting stage to the maturation stage,and there was a significant difference between N4 and control.Compared with to the control group,increasing the nitrogen application rate improved the stem matter quality,of which N3 and N4 were significantly higher than control.In the filling stage,N3 significantly increased the dry matter accumulation of bract and female ear,and both N3 and N4 significantly increased the dry matter accumulation of bract and female ear at the booting stage and the maturation stage.The total dry matter accumulation of N4 was significantly higher than control,N2 and N3.The comprehensive analysis showed that N4 had the best effect on increasing the dry matter accumulation of maize.

Key words: Nitrogen fertilizer, Maize, Dry matter accumulation