Effects Of Nitrogen Dressing Period And Proportion On Physiological Characteristics And Yield And Quality Of Wheat With Different Gluten Types

In order to study the comprehensive effect of nitrogen topdressing period and ratio on yield and quality of different wheat varieties,this paper studied the effect of nitrogen topdressing ratio on yield and quality of wheat under the condition of quantitative control,in order to realize cost-saving and efficient production mode of different special wheat in huang-Huai Winter wheat area.The experiment was conducted in the Middle Farm experimental base of Institute of Crop Sciences,Chinese Academy of Agricultural Sciences from 2020 to 2021.The effects of nitrogen fertilization period and ratio on photosynthetic physiological indexes,nitrogen accumulation in vegetative organs,grain filling rate,agronomic traits,yield and quality of two kinds of gluten wheat were studied.The split plot design was adopted in the experiment.The main plot was variety,including four wheat varieties,taishan 27（C1）and Zhongmai 578（C2）.The two weak gluten wheat varieties were Yangmai 15 for C3 and Yangmai 24 for C4.The sub-region is the ratio of nitrogen replacement in different periods.The sub-region is the ratio of nitrogen replacement in different periods.During the whole growth period,240 kg/hm²of pure nitrogen was applied,with 50%as base fertilizer and the rest as jointing fertilizer and booting fertilizer,and the ratio of nitrogen topdressing N1 was100%:0%;N2 was 75%:25%;N3 is 50%:50%;N4 is 25%:75%;N5 is0%:100%.The sowing method is drill sowing（3 million plants/hm²）.P₂O₅172.5 kg/hm²,K₂O 112.5kg/hm²and pure nitrogen 120 kg/hm²were applied uniformly before sowing.and top nitrogen application was 120 kg/hm²in each treatment.The main results are as follows:1.There were significant differences in the effects of nitrogen dressing period and ratio on photosynthetic physiological indexes of wheat with different gluten types.The net photosynthetic rate and SPAD value of flag leaf reached the maximum value at jointing and booting stages with 50%nitrogen treatment:50%treatment increased 13.3%and 7.41%compared with only booting stage,respectively.The net photosynthetic rate and SPAD value of the strong gluten varieties were higher than those of the weak gluten varieties,and decreased slowly at the late growth stage.2.The effects of nitrogen topdressing period and proportion on nitrogen accumulation in different organs of wheat with different gluten types were significantly different.The nitrogen content in stem+sheath of the two gluten wheat at maturity reached the maximum in the topdressing nitrogen treatment only at jointing stage,which increased by 46.96%compared with the topdressing nitrogen treatment only at booting stage;The nitrogen content of leaves in topdressing treatment was only 39.76%higher than that in booting stage;The nitrogen content of glume+cob and grain in jointing stage and booting stage was 25%:75%treatment reached the maximum value,which was increased by 21.56%and 8.21%respectively compared with the minimum value.The nitrogen content of vegetative organs of Different Gluten Types of wheat at maturity was grain>glume+cob>leaf>stem+sheath.3.There were significant differences in the effects of nitrogen fertilization stage and proportion on plant and spike traits of wheat with different gluten types.Plant height,spike length and spikelet number reached the maximum value at jointing stage and booting stage with nitrogen fertilization ratio of 75%and25%respectively,which increased by 3.31%,6.21%and 3.85%compared with booting stage alone.The number of sterile spikelets reached the minimum at booting stage and was reduced by 8.42%compared with that at jointing stage.The plant height and panicle length of weak gluten were significantly higher than those of strong gluten,while the number of sterile spikelets of strong gluten was significantly lower than that of weak gluten.4.There were significant differences in the effects of nitrogen dressing period and proportion on yield and components of wheat with different gluten types.The grain yield,grain number per spike and1000-grain weight of the two gluten types of wheat were 50%at jointing stage and booting stage:the 50%treatment reached the maximum value,and the grain yield increased by 8.80%compared with the single treatment at booting stage.The number of panicles per unit area reached the maximum in only jointing stage and increased by 12.60%compared with only booting stage.Grain yield,panicle number per unit area and 1000-grain weight of strong gluten varieties were significantly higher than those of weak gluten varieties.5.There were significant differences in total starch content,protein content and components content among different gluten types in nitrogen dressing period and proportion.The total starch content reached the maximum value at the jointing stage and increased by 7.17%compared with the minimum nitrogen ratio of 25%at jointing stage and booting stage.The total starch content of weak gluten was significantly higher than that of strong gluten.Total starch content was negatively correlated with protein content.The proportions of protein,albumin and globulin contents in grains were 20%at jointing and booting stages,and 75%reached the maximum value,which increased by 6.11%,12.00%and 7.10%compared with that at jointing stage only.The contents of protein,gliadin and gluten in strong gluten varieties were significantly higher than those in weak gluten varieties,but the contents of globulin were lower than those in weak gluten varieties.Under the conditions of this experiment,the high yield and high quality of weak gluten wheat could be achieved when the ratio of nitrogen application was 100%:0%at jointing stage and booting stage.The evaluation standard of high-quality strong gluten wheat is high protein content and low starch content,so the high gluten varieties can meet the requirements of cost-saving and efficient agricultural production when the ratio of nitrogen application is 50%at jointing stage and booting stage.