Effect Of Ratios Of Base And Top-dressing Nitrogen Fertilizer On Some Physiological Characteristics And Yield Of Wheat Under Waterlogging Stress At Booting Stage

The experiment was conducted in Anhui agricultural university, to ascertain the e ffect of ratios of base and top-dressing nitrogen fertilizer on physiological characterist ics of wheat Zhoumai22under waterlogging stress at booting Stage. In this study, fo ur nitrogen management and two waterlogging treatments were designed, respectively. The results were as follows:1. Effect of ratios of base and top-dressing nitrogen fertilizer on photosynthesis characteristics of wheat under waterlogging at booting stageThe chlorophyll content, leaf area index (LAI), dry matter accumulation of wheat flag leaf at booting stage were showed an increase trend with the nitrogen application.21days after fertilization at booting stage (15May), the chlorophyll content, LAI, dry matter accumulation of the nitrogen application treatment (based fertilizer:jointing fertilizer: booting fertilizer=3:5:2) were higher17.3%,44.4%,25.1%than the treatment (10:0:0). It showed that the nitrogen application could increase chlorophyll content, LAI, dry matter accumulation under normal growth condition.The waterlogging at booting had significantly negative effect on photosynthesis characteristics; it makes chlorophyll content, leaf area index (LAI), dry matter content decreased. The nitrogen management treatment (based fertilizer:jointing fertilizer:booting fertilizer=3:5:2) greatly increased the chlorophyll content, LAI, dry matter content of flag leaf under waterlogging at booting stage. After21days (5/15), the nitrogen management treatment (3:5:2) was18.7%higher than the treatment (10:0:0) on the chlorophyll content,121.1%on LAI,40.8%on dry matter content.2. Effect of ratios of base and top-dressing nitrogen fertilizer on root activity of wheat under waterlogging at booting stageFrom Overwintering stage to booting stage, the number of secondary roots increased over time in every treatment, and reached the maximum at the booting stage. The nitrogen management treatment (3:5:2) is65.2%higher than the treatment (10:0:0) on the number of secondary roots and56.2%on the activity at booting stage. The nitrogen management was beneficial to increase the number of secondary roots and the activity. The results showed that the nitrogen management one hand enable delay root senescence, on the other hand, will help reduce the harmful of waterlogging.3. Effect of ratios of base and top-dressing nitrogen fertilizer on senescence of wheat under waterlogging at booting stage Effects on growth and development of flag leaf at booting stage, SOD, POD activity and MDA content were studied. The treatment with Nitrogen management3:5:2, at booting stage, it could delay the senescence of flag leaves, keep the activities of superoxide dismutase (SOD) and peroxidase (POD) at a higher level, which resulted in increasing winter wheat yield. The nitrogen management treatment (3:5:2) is85.9%higher than the treatment (10:0:0) on the activities of POD and12.8%on the activity of SOD at booting stage.4. Effect of ratios of base and top-dressing nitrogen fertilizer on yield and its components of Wheat under waterlogging at booting stageThe nitrogen management treatment (3:5:2) significantly increased the number of wheat tillers.It was24.5%higher than the treatment (10:0:0). The number of spikes, kernels and grain weight increased with nitrogen topdressing rate increasing. In this treatment, output reached7481.6kg/hm2, the highest of all treatments.Waterlogging would tend to decrease the yield of zhoumai22. Nitrogen management increased the yield under waterlogging stress. The nitrogen management treatment (3:5:2) was44.1%higher than the treatment (10:0:0) on the yield,6.7%on the number of kernels,8.5%on grain weight under waterlogging stress.