Effects Of Different Nitrogen Application Rate On Grain Yield And Quality And Nitrogen Fertilizer Use Of High-yield Winter Wheat

Under the field conditions, effects of nitrogen (N) application rate on Population Dynamics,Photosynthesis Characteristics , Dry Matter Accumulation, Panicle Development, Carbon and Nitrogen Metabolism,Grain Yield,Quality,and Nitrogen Use Efficiency of winter wheat were studied taking two type cultivars (Yumai 49-198 and Lankao aizao8) as experimental wheat cultivars. Five N rates (0, 90, 180, 270 and 360 kg N ha-1) with three replications were applied at two sites(Wenxian and Lankao) of Henan province in China.The main results were as follow:1: Effects of different nitrogen rate on population dynamics of winter wheatThe results showed that two varieties of wheat has similar tillering stage, tillering stage were all at the jointing stage, after jointing stage, were falling sharply, and stabilizing on flowering stage. Analysis of the survey data , Wenxian point Yumai 49-198 on autumn the number of ear were differences with others ,The other ways and Lannko sites were all consistent , indicating that base on high yield research in the field of high fertility, the number of tillers per unit area and into the spike number has basically reached saturation, by increasing N to improve the tiller and the number of tillers and spike was impossible. LAI changes in the two wheat varieties was all increasing until anthesis, Pol. Yumai 49-198 each time showed N270> N360> N180> N90> N0, but the difference was not significant, but Lankao is shown as N180> N270> N360> N90> N0, little difference between pre-flowering stage .N2 significantly higher than N0 in anthesis, indicated that the proper amount of nitrogen can reduce green leaf area at later growing stages, to increase weight and yield.2. Effects of different nitrogen rate on photosynthetic characteristics of winter wheatAccording to the results of this study, ultra high-yield wheat field used enough fertilizer, and the ratio N P K was reasonable, under the premise of Lankao of pure nitrogen per hectare, 180kg, Yumai 49-198 per hectare nitrogen application 270kg, can significantly improve wheat flag leaf photosynthetic rate. Low nitrogen levels can significantly decrease photosynthetic rate of wheat, wheat tiller too much in high nitrogen conditions, larger groups, resulting lower photosynthetic rate; Optimum nitrogen rate significantly increased after flowering SPAD value of flag leaf, when the nitrogen application rate is less than 270 kg / ha, with the SPAD value of raising the level of nitrogen increased, the N360 kg / ha SPAD value decreased, indicating that more high nitrogen may group grow too fast .consumption of excessive nutrients, to the late filling to accelerate leaf senescence, resulting in lower chlorophyll content, thereby affecting the material accumulation and grain yield.3. Effects of different nitrogen rate on carbon metabolism of winter wheatYumai 49-198 of sucrose synthase (SS) and flag leaf sucrose phosphate synthase (SPS) were spent after the 14d reached the maximum, while the flower Lankao 21d later than the maximum of SPS, appropriate nitrogen (N180, N270) in the filling stage of (after flowering 14-21d) to maintain high activity with the enzyme, and can effectively improve the content of sucrose after flowering, which can transfer the accumulation of starch grains to provide adequate library source. Low nitrogen and high nitrogen before flowering material transport and the accumulation after flowering were all lower than medium N treatment, indicating that the content of nitrogen can effectively improve the transfer content of dry matter and rate of transfer, and improve the dry matter contribution to grain accumulation.4. Effects of different nitrogen rate on nitrogen metabolism of winter wheatThere were effects on different nitrogen application rate on translocation of pre-anthesis stored nitrogen and post-anthesis assimilation .but increased with the amount of nitrogen decreased, while the nitrogen treatment (N180, N270) General total volume of transit traffic transit higher level of nitrogen treatment has remained relatively high GS activity is conducive to nitrogen metabolism and accumulation, to improve the grain filling, grain weight increased to a certain extent; in the N treatment and to maintain leaves and grain content of free amino acids for protein synthesis to provide the largest library sources5. Effects of different nitrogen rates on spike and floret development of winter wheatThere were no significant difference in young spike development process during Wintering Period, while different location and different nitrogen rates. After the period of turning green, there were differences between different treatments, low N rate caused high speed of young spike development process,and the yong spike development process was slower in high N rate. In early days ,the spike development of yumai49-198 was slower than lankaoaizao8,but achieved the same level in later period. A peak of young spike degradation was appeared at 20 days after jointing in lankaoaizao8. In medium N rate,the spike development process was gentle, but have more floret and perfect floret.In high N rate , spike development process was slow ,and has fewer perfect floret. The regularity of spike development and floret of yumai49-198 was medium N rate = low N rate > high N rate , the regularity of lankaoaizao8 was medium N rate = high N rate > low N rate.6.Effects of different nitrogen rates on yield components and processing quality of winter wheatWhen application rate of N fertilizers is 180-270 kg/hm2, Both varieties of wheat have reached the highest yield in the two Experimental site, and have achieved super-high yield index. In the effects of N rates on yield components, the impact of grain number and 1000-grain weight was significant, and the impact of grain number of different treatment was not significant. With production levels increasing and key targets changing, it shows that, application of the optimum amount of N rates , has great significance on adjustmenting plants carbon and nitrogen ratio,improving the quality of groups, increasing grain numbers,raising grain weight,and achieve super-high yield finally base on a enough stable spike numbers.[17]The experiment used two wheat varieties appear in both the highest yield areas of different N rates requirements, it comfirmed that there are differents between the nitrogen nutrition characteristics of the two varieties.[8]Increasing N application rate is helpful for improving the extensograph parameter and the falling number, the effects was not significant when the nitrogen application reaches a certain amount. With the nirtrogen application increase, pasting properties shows positive correlation trend ,only the break-down shows the reserved trend. Based on increasing production, it shows that a reasonable N rates is helpful to ameliorate the processing quality of winter wheat.7,Effects of different nitrogen rate on nitrogen use efficiency of winter wheatIn the whole period the wheat nitrogen cumulant increases unceasingly, after the jointing the nitrogen absorbing capacity approximately composes to the nitrogen total absorbing capacity 2/3. The Yumai 49-198 various spots nitrogen content, the shift quantity, the technical progress factor are all biggest by 270 kg/hm2 nitrogen level under, but the Lankao short eight pieces are early biggest by 180 kg/hm2 nitrogen level under.The nitrogen shift quantity and between Shi Danliang conforms to a Yuan quadratic equation, also with the grain output remarkable correlation, after the flower the nitrogen assimilation quantity and between Shi Danliang does not have the obvious rule.Increases along with the nitrogenous fertilizer amount used, nitrogen absorption efficiency, nitrogen use efficiency, nitrogenous fertilizer leaning productive forces remarkable drop.The Yumai 49-198 every 100 kilogram output nitrogen carries off the quantity, the nitrogenous fertilizer works as the season use factor all is highest by 270 kg/hm2 nitrogen level under; Lankao short eight is early highest by 180 kg/hm2 nitrogen level under.The nitrogen agronomy efficiency all is highest by 180 kg/hm2 nitrogen level under, under 360 kg/hm2 nitrogen level is lowest.