Technology Approach To Synergistically Improve The Yield,Quality And Nitrogen Use Efficiency Of Strong Gluten Wheat

In the two consecutive wheat growing seasons 2017-2019,a field experiment was conducted in Dongwu Village,Dawenkou Town,Daiyue District,Tai’an City,Shandong Province,using winter wheat large-spike variety Zhouyuan 9369 as the test material.The experiment set 4 sowing dates（October 8,S1）,（October 15,S2）,（October 22,S3）,（October29,S4）,and 3 planting densities(low density 225×10⁴ hm^-2,medium density 375×10⁴ hm^-2,high density 525×10⁴ hm^-2)and 3 nitrogen fertilizer topdressing ratios（50%,60%,70%）.The split zone design is adopted,with the sowing date as the main zone,the density as the split zone,and the ratio of nitrogen topdressing as the split zone.The effects of sowing date,density and nitrogen topdressing ratio on grain yield,quality and nitrogen use efficiency of strong gluten winter wheat are studied.The research results are as follows:1 The influence of sowing date,density and nitrogen fertilizer topdressing ratio on yield and yield componentsThe sowing date was postponed from October 8 to October 22.The increase in the number of ears per ear compensated for the decrease in the number of ears per unit area,and the yield was stabilized.However,when the sowing date continued to be postponed to the 29th,due to the number of ears per unit area.And the number of grains per panicle decreased,and the grain yield showed a decline.When the planting density is increased from 225×10⁴ hm^-2to 375×10⁴ hm^-2,the increase in the number of spikes per unit area is higher than the decrease in the number of spikes and grain weight,and the grain yield increases,but when the density increases to 525×10⁴ hm^-2,the grain yield decreases.The proportion of topdressing nitrogen increased from 50%to 70%,which increased the number of ears per unit area and the number of grains per ear.There was no significant difference or slight decrease in grain weight,and grain yield increased.2 Effect of sowing date,density and topdressing ratio of nitrogen fertilizer on nitrogen use efficiency and related indexesWhen the seeding date is delayed,the amount of nitrogen accumulation during the anthesis period,the amount and rate of nitrogen transport before anthesis decrease,and the amount of nitrogen accumulation decreases during the mature period.The sowing date was postponed from October 8 to 22th.The increase in nitrogen use efficiency（UTE）can compensate for the decrease in nitrogen absorption efficiency（UPE）,and the nitrogen utilization rate（NUE）remains stable;the sowing date is further postponed to the 29th,The increase in UTE cannot compensate for the decrease in UPE,resulting in a decrease in NUE.Increasing the density and the ratio of topdressing nitrogen will increase the nitrogen accumulation during the anthesis period of winter wheat,the nitrogen accumulation after anthesis and the nitrogen transport before anthesis,and the nitrogen accumulation during the mature period.As the planting density increased from 225×10⁴ hm^-2to 375×10⁴ hm^-2,the increase in UPE was higher than the decrease in UTE,and NUE increased.When the density increases to 525×10⁴ hm^-2,the increase in UPE can be lower than the decrease in UTE,and NUE decreases.3 Effects of sowing date,density and nitrogen fertilizer topdressing ratio on grain quality and protein compositionDelayed sowing date,wet gluten content,sedimentation value,farinograph index,extensometer index,bread volume and bread score all showed a decrease.Increasing the density and increasing the ratio of topdressing nitrogen improves the wet gluten content,sedimentation value,dough formation time,dough stability time,stretch area,ductility,stretch resistance,maximum stretch resistance,bread volume and bread score.Postponed sowing date,protein content,gluten content,gliadin content,lactol ratio,polymerization index,gluten subunit content and high molecular weight subunit/low molecular weight subunit decreased.Increasing the density and increasing the ratio of topdressing nitrogen,protein content,gluten content,gliadin content,gluten alcohol ratio,polymerization index,gluten subunit content and high molecular weight subunits/low molecular weight subunits increase accordingly.Grain protein components are significantly positively correlated with quality indicators.4 Technical approaches for synergistic improvement of yield,quality and nitrogen utilizationOptimizing the planting density increases the number of ears per unit area,and the optimization of the nitrogen topdressing ratio increases the number of ears per unit area and the number of grains per ear to increase the number of grains per unit area.Under the condition that the grain weight remains the same or decreases,it is realized Increase in grain yield.At the same time,optimizing the planting density and the ratio of nitrogen topdressing increased the absorption of nitrogen before and after the anthesis period,and the transfer of nitrogen to the grain during the grain filling process,and the increase in the number of grains per unit area was greater.Thereby increasing the grain protein content and single grain nitrogen content.As a result,the grain protein composition is improved,and the gluten/gliadin ratio,gluten polymerization index and HMW-GS/LMW-GS ratio are improved.The grain protein content and protein constituents improve the quality of bread making.While optimizing the planting density and the ratio of nitrogen topdressing,the total nitrogen supply has not changed.Therefore,the nitrogen utilization rate increases with the increase in yield.In terms of synergistically improving grain yield,quality and nitrogen use efficiency,the additive effect of optimizing planting density and nitrogen topdressing ratio is significantly better than the independent effect of the two factors,and the general trend is not affected by sowing date.