Abstract:

In order to investigate whether the current nitrogen application in Tianjin area was reasonable, the parent waxy maize varieties (‘Hei 943’ and ‘Jin 872’) and their hybrid variety (‘Jinheinuo 6’) were used as materials and then treated with three nitrogen fertilizer levels (low N, middle N, and high N rates) to study the effects of nitrogen fertilizer levels on photosynthetic characters and yield traits in this paper. The results indicated that nitrogen fertilizer levels did not significantly affect diurnal changes of net photosynthesis rate or transpiration rate of waxy maize (P>0.05) but low nitrogen application could increase net photosynthesis rate (41.8 μmol/(m2?s)) of hybrid variety from jointing stage to trumpet shaped stage (August 6). Nitrogen rates had no significant effects on yield traits while varieties were the dominant factors determining crop yield (P<0.05). Our study suggested that, properly decreasing nitrogen application would not influence photosynthetic characters or yield traits of waxy maize but also reduced agricultural production input and effectively alleviated environmental pressure due to excessive fertilizer application.