Abstract: In order to explore the effect of nitrogen application rate on photosynthetic rate of winter wheat under different light intensities,the study was based on the nitrogen control test of research plots,and four levels of nitrogen application and five light intensities were set to analyze the response of nitrogen fertilizer to nitrogen content of winter wheat leaves and to study the effects of light intensity and leaf nitrogen on the net photosynthetic rate of winter wheat leaves.The results showed that leaf nitrogen content gradually increased with the increased of nitrogen application rate,excessive nitrogen application could inhibit the increase of leaf nitrogen content at the beginning of grain filling and mid-grain filling. From jointing to mid-grouting stage,leaf nitrogen content had been declining generally,and the net photosynthetic rate of winter wheat increased with the increased of light intensity. The photosynthetic rate increased first and then decreased at low nitrogen application rates,while in the absence of nitrogen and medium and high nitrogen application with the growth period the photosynthetic rate showed downward trend. There was a significant positive correlation between net photosynthetic rate and leaf nitrogen content under the artificially controlled fixed light intensities,and the photosynthetic rate increased with the increased of nitrogen content. Therefore,a moderate application of nitrogen fertilizer in winter could increase the photosynthetic rate of winter wheat.

Key words: Winter wheat, Amount of nitrogen, Light intensity, Nitrogen content of leaves, Photosynthetic rate

CLC Number: 

• S143.1