Effects of Different Nitrogen Forms and Different Levels on Leaf Physiological Indexes of Cucumber Seedling

[Objective] The aim was to study effects of different nitrogen forms and different levels on leaf physiological indexes of cucumber seedling,and provide some reference for using N fertilizer scientifically and reasonably,for enhancing cucumber yield and improving cucumber quality.[Method] Taking Dayesan cucumber as material,pot experiment was tested in solar greenhouse,there were 16 treatments with 3 N fertilizers,such as CO(NH2)2,NaNO3 and NH4HCO3 under the concentrations of 200,300,400,500 and 600 kg/hm2,and the control that was without N fertilizer.[Result] When the concentration of NH4HCO3 was 600 kg/hm2,the chlorophyll content in cucumber leaf was highest,reached to 2.37 mg/gFW.When CO(NH2)2 concentration was 500 kg/hm2,the soluble sugar content was highest,and 9.82 mg/gFW,when 300 kg/hm2,the content of Vc reached to 0.563 2 mg/100 g.The concentrations of 3 N fertilizers all were 600 kg/hm2,the nitrate N contents were 0.18%,there were different effects of N fertilizer under different levels on photosynthesis intensity of cucumber seedling.When the concentration of CO(NH2)2 was 400 kg/hm2,the respiration intensity was strongest,reached to 0.128 mg/(dm2·h).[Conclusion] Urea was the more suitable fertilizer for growth of cucumber seedlings.