Study on the Effect of Different Nitrogen Treatments on the Photosynthesis and Yield after the Wheat Anthesis

To explore the effect of different nitrogen treatments on the photosynthesis and yield after the wheat anthesis,the randomized block experiment was carried out.The results show that with the decrease of the nitrogen in the grain filling period,the chlorophyll content and the photosynthetic rate(Pn) were decreased,and with the time went on,the rate of nitrogen decreased faster.The reasonable application of nitrogen fertilizer and the proper delay of the application can significantly increase the chlorophyll content and the photosynthetic rate,and extend the function period of leaves.Within the 150-330kg nitrogen fertilized in each hectare,each nitrogen treatment significantly increased the control treatment,of which the treatment of 330kg/hm2 nitrogenous increased the yield most.In this treatment,the fertilization ratio of NPK fertilizer(N: P2O5: K2O) was 1:0.44:0.41,the nitrogen distribution ratio is that 60% base fertilizer: 20% jointing fertilizer: 20% top dressing in booting..