Effects Of Nitrogen Application On Grain Yield, Nitrogen Uptake And Utilization And Quality Of Different Strong Gluten Wheat Cultivars

The field experiments were carried out in 2015-2016 and 2016-2017 at the Agricultural Experiment Station of Shandong Agricultural University.Five strong gluten wheat cultivars including Yannong 19,Jimai 20,Jinan 17,Zhouyuan 9369 and Gaocheng 8901 were used as experimental materials to study the differences of yield,nitrogen use efficiency,quality and their related indices at 0,120,180,240 and 300 kg·ha^-1 nitrogen levels.Split-zone design was used.Nitrogen fertilizer was the main factor and cultivars were the secondary factor.The main results were shown as follows:The effects of nitrogen level,variety and their interaction significantly affected grain yield,nitrogen utilization efficiency,nitrogen uptake efficiency,nitrogen use efficiency,development time,stability time and loaf volume of winter wheat,which showed that the yield,nitrogen use efficiency and quality of different gluten winter wheat cultivars were inconsistent with different nitrogen fertilizer levels.It was necessary to analyze and screen synergistic high-yield,high-efficiency and high-quality cultivars at different nitrogen fertilizer levels.1 Effects of nitrogen application on grain yield of different strong gluten wheat cultivarsThe yield of all strong gluten wheat cultivars increased first and then decreased with the increase of nitrogen fertilizer and reached the highest proportion of high-yield cultivars when nitrogen application amount was 240 kg·ha^-1.The spike per unit area of different strong gluten wheat cultivars increased as the increase of nitrogen fertilizer level and reached the maximum under N300 conditions.The kernel number showed a trend of increasing first and then decreasing with the increase of nitrogen fertilizer level,reaching the maximum under N240 conditions.1000-kernel weight decreased as the level of nitrogen fertilizer increased.Under the same nitrogen application,the yields of different cultivars differed significantly.Under N0 and N120 in 2016 and N0 in 2017,the yields of Jinan 17 and Zhouyuan 9369 were both higher.Under the other nitrogen application levels,compared with other 4 strong gluten wheat cultivars,Zhouyuan 9369 had the lowest spike,which was30.46%lower than the other four cultivars.The 1000-kernel weight was in the upper and middle levels of the five cultivars,but the kernel number was 35.56%higher than other cultivars.The higher number of grains made up for and exceeded the shortage of spike.The output of the five cultivars of Zhouyuan 9369 was higher under other nitrogen levels.2 Effects of nitrogen application on nitrogen uptake and use of different strong gluten wheat cultivarsThe nitrogen uptake efficiency,nitrogen use efficiency,and nitrogen utilization efficiency of all strong gluten wheat cultivars decreased with the increase of nitrogen levels.When the nitrogen application amount increased from N0 to N300,the reduction rate of nitrogen absorption efficiency was 39.94%,6.70%,9.39%and 20.22%,respectively.The reduction rate of nitrogen use efficiency was 17.70%,11.88%,7.31%and 2.56%,respectively.And the reduction rate of nitrogen utilization rate was 49.54%,19.00%,17.25%and 20.95%,respectively.This indicates that excessive application of nitrogen will reduce the utilization rate of nitrogen in wheat.There were differences in nitrogen uptake efficiency,nitrogen use efficiency,and nitrogen utilization efficiency among different strong gluten wheat cultivars.Under N0 and N120 in 2016 and N0 in 2017,the nitrogen utilization rates of Jinan 17 and Zhouyuan 9369were both higher.At other levels of nitrogen application,compared with other four strong gluten wheat cultivars,the nitrogen absorption efficiency of Zhouyuan 9369 was 0.75%lower than that of the other four cultivars.However,the nitrogen use efficiency was higher than that of other four strong gluten wheat cultivars.The average cultivars were 14.80%higher respectively.The higher nitrogen use efficiency made up for and exceeded the deficiency of nitrogen absorption efficiency.Therefore,the nitrogen utilization rate of five cultivars,Zhouyuan 9369 was the highest.It shows that Zhouyuan 9369 has a higher ability to use nitrogen absorption for grain production and potential to reduce nitrogen level.3 Effects of nitrogen application on quality of different strong gluten wheat cultivarsThe loaf volume of strong gluten wheat cultivars increased with the increase of nitrogen application amount;development time,stability time and loaf score increased first and then decreased with the increase of nitrogen application amount.Development time and stability time were highest in N180 condition.And loaf scores was highest in N240 condition.It shows that the appropriate application of nitrogen fertilizer is beneficial to the improvement of wheat quality,but excessive application of nitrogen fertilizer is not conducive to the improvement of wheat quality.At the same level of nitrogen fertilizer,the development time,stability time,loaf volume and loaf score of different strong gluten wheat cultivars were significantly different.Compared with other four strong gluten wheat cultivars,Zhouyuan 9369 had the highest development time,stability time,loaf volume and loaf score.It shows that Zhouyuan 9369has better bread quality.The SDS-soluble glutenin content of all strong gluten wheat cultivars increased with the increase of nitrogen application amount;total protein,SDS insoluble glutenin,total glutenin and aggregation index increased first and then decreased with the increase of nitrogen application amount.They reach the highest level at N180 or N240.The results showed that the appropriate application of nitrogen fertilizer could increase the content of protein and its components and the degree of aggregation of glutenin,while high nitrogen application could increase the ratio of SDS-soluble glutenin,but other indicators decreased to varying degrees,especially SDS-insoluble glutenin and glutenin aggregation index.Compared with other four strong gluten wheat cultivars,the total protein content of Zhouyuan 9369 was lower,but SDS soluble glutenin,SDS insoluble glutenin and total glutenin were higher than other cultivars,resulting in the aggregation index of Zhouyuan9369.It is higher than other strong gluten cultivars on average.It shows that compared with the total protein content,the degree of glutenin polymerization is the main factor affecting wheat quality and related indicators.