Effects Of Nitrogen Fertilizer Regulation On Lodging Resistance Traits,Yield And Quality Of Two Gluten Wheats

The trail was conducted in Kangcheng Village,Yuzhou City,Henan Province from2019-2020 and 2020-2021.In this experiment,six wheat varieties were selected from Yumai49-198,Yannong1212,Huayu198(ordinary wheat),Xinong979,Jimai44 and Xinmai26(strong gluten wheat).And we set 5 nitrogen application levels(pure nitrogen 0,120,180,240,360kg/ha).From 2021-2022,two varieties of Huayu198 and Xinmai26 and 5 nitrogen levels were selected to continue the experiment,and the nitrogen fertilizer operation test was set up,and 180kg/ha of nitrogen fertilizer was applied,which was divided into 8 treatment applications: T1: no nitrogen fertilizer,T2:one-time base application,T3:1/2 base application + 1/2 jointing topdressing,T4:1/2base application +1/2 rejuvenation topdressing,T5:2/3 base application +1/3 jointing topdressing,T6:1/3 base application + 2/3 jointing stage topdressing,T7:1/3 base application + 2/3 filling topdressing,T8:1/3 base application + 1/3 jointing +1/3filling topdressing,explore the effects of nitrogen application rate on wheat yield,lodging resistance and quality,so as to find the nitrogen application rate suitable for local production,in order to provide scientific basis for reasonable wheat cultivation measures and yield improvement,quality improvement and collapse resistance,the main results are as follows:1 Effects of nitrogen application rate and nitrogen fertilizer operation on lodging resistance traits of wheat with different gluten levelsBy increasing the application of nitrogen fertilizer,the plant height and gravity center height of the two types of wheat were increased,and the agronomic traits such as stem diameter,stem breaking strength and stem piercing force were reduced,which significantly reduced the lodging resistance index of wheat stems,thereby increasing the risk of lodging.The lodging resistance index is closely related to the lodging resistance of wheat stems,and the lodging resistance index of medium gluten wheat has a greater lodging resistance index than that of strong gluten wheat,but with the increase of nitrogen application,its decline rate is much greater than that of strong gluten wheat,so it can be considered that the lodging resistance of medium gluten wheat varieties in this experiment is more sensitive to nitrogen application than strong gluten wheat.Under the treatment of T3 and T4,the lodging resistance index of medium gluten wheat huayu198 is high,that is,under the same conditions as nitrogen fertilizer base fertilizer,topdressing at the jointing stage or rejuvenation stage can ensure that the lodging resistance index is at a high level.The lodging resistance index of strong gluten wheat Xinmai26 was higher under the treatment of T4,T7 and T8,that is,topdressing in the rejuvenation stage,or moving top dressing to the pregnant ear stage,or dividing the top dressing in the pregnancy panicle stage into two topdressing applications of jointing and pregnant ear,which could improve the lodging resistance index.For the anatomical structure of stems,the number of large and small vascular bundles was significantly negatively correlated with the lodging resistance index.With the addition of nitrogen fertilizer,the number of large and small vascular bundles increased to varying degrees.The mechanical tissue thickness of stem had no significant effect on nitrogen application,while the wall thickness decreased to varying degrees with the increase of nitrogen application.For Huayu198,increasing the proportion of nitrogen fertilizer base fertilizer can increase the number of small vascular bundles and the area of large vascular bundles on stems,so it may increase the risk of lodging.Under the T7 treatment,the number and area of large and small vascular bundles were at a low level in Xinmai26,that is,nitrogen fertilizer was moved to the gestational stage,which was conducive to improving the lodging resistance of stems.The cellulose content of stem was significantly negatively correlated with the lodging resistance index,and with the increase of nitrogen application,except for the other five varieties of wheat 26,the cellulose content of stem increased to varying degrees,but all showed a short-term downward trend under a certain nitrogen level treatment.Overall,the addition of nitrogen fertilizer reduced the lodging resistance index of stems by increasing the cellulose content of stems.The cellulose content of Xinmai26 under nitrogen application treatment was lower than that under no nitrogen treatment.The cellulose content of stem wheat is higher than that of medium gluten wheat overall,so it is once again proved that strong gluten wheat has a weaker lodging resistance.The contents of potassium,calcium and magnesium in wheat stem mineral nutrients were significantly negatively correlated with lodging resistance index.The application of nitrogen fertilizer significantly increased the content of these elements in the stems of the two types of wheat,and increased with the increase of nitrogen application.These characteristic changes in stems are the reason why the lodging resistance of stems decreases with the increase of nitrogen application.2 Effects of nitrogen application rate and nitrogen fertilizer operation on wheat yield of different gluten levelsThe dry matter accumulation was the basis for yield formation,and the dry matter accumulation and grain yield of medium-gluten wheat were higher than those of strong-gluten wheat.The results of nitrogen fertilizer application in the first two seasons showed that the optimal yield and optimal benefit nitrogen application rate of the two types of gluten wheat were 180kg/ha,and the results of the nitrogen fertilizer operation test on this basis showed that increasing the amount of nitrogen fertilizer base fertilizer or advancing the top dressing period could improve the yield and economic benefits of the two types of gluten wheat.With the increase of nitrogen fertilizer use,the nitrogen uptake efficiency,nitrogen use efficiency,nitrogen fertilizer partial productivity and harvest index of the two gluten wheat showed a continuous trend of decrease,and the nitrogen distribution of grain was also reduced.Increasing the proportion of nitrogen fertilizer base fertilizer and advancing the nitrogen topdressing time can improve the nitrogen accumulation,nitrogen absorption efficiency and nitrogen fertilizer partial productivity to a certain extent.As the main constituent of the canopy in the late stage of wheat,the photosynthetic changes of flag leaves can basically represent the trend of canopy photosynthesis,which directly affects the photosynthetic products and grain yield.The application of nitrogen fertilizer can effectively increase the SPAD value of flag leaves,but at the same time,it also reduces ΦPSII.,increases ΦNO,reduces the chlorophyll fluorescence rate,and may have the risk of accelerating leaf aging,thereby reducing yield.3 Effects of nitrogen application rate and nitrogen fertilizer operation on grain quality of wheat with different gluten levelsIn the nitrogen fertilizer dosage test of wheat in two crops,the crude protein and wet gluten content of strong gluten wheat grain reached the national secondary standard nitrogen application range of 149.3-245.7kg/ha and 177.9-182.9kg/ha,respectively.Therefore,a certain amount of nitrogen fertilizer input must be ensured to meet the grain quality.On the basis of N180 nitrogen treatment,each fractional fertilization treatment can achieve the crude protein and wet gluten content of strong gluten wheat grain.In summary,the effect of lodging resistance on nitrogen application rate of the two gluten wheat was not consistent.Medium gluten wheat is more sensitive and the lodging resistance index decreases faster,but reasonable nitrogen fertilizer management can make medium gluten wheat have a greater lodging resistance index than strong gluten wheat,that is,the lodging resistance of strong gluten wheat is not as good as that of medium gluten wheat.By adjusting the agronomic traits of stems,increasing the number,area,cellulose and mineral nutrient elements of vascular bundles,increasing the lodging resistance of wheat,increasing the amount of nitrogen fertilizer base fertilizer or moving back of nitrogen fertilizer topdressing can increase the strength of wheat stems in the gestational stage to a certain extent,thereby improving the lodging resistance of stems and reducing the risk of lodging in the late growth period.Under the N180 treatment,although the yield of the two gluten wheat is not the highest,it can ensure the best economic benefits.The lodging resistance index and yield of medium gluten wheat Huayu198 can reach a relatively high level under T4 or T3 treatment,and the yield of strong gluten wheat Xinmai26 is higher under T4 treatment,and the lodging resistance index is at the upper middle level and the quality is up to standard.Therefore,the recommended nitrogen application rate of 180kg/ha for fertilization under local conditions,2/1 base application,and 1/2 topdressing in the rejuvenation stage or jointing stage.Strong gluten wheat 26 recommended 180kg/ha nitrogen application rate,1/2 base application,1/2 topdressing in the rejuvenation stage.