Differences Of Nitrogen Concentration And Establishment Of Critical Nitrogen Concentration Dilution Curve In Different Wheat Genotypes

Field experiments with Yumai 49-198,Zhoumai 16 and other 10 wheat genotypes were conducted in Yu Zhou Henan province,,difference of wheat plant nitrogen content,yield and yield components were researched,according to the difference of wheat nitrogen production efficiency and utilization efficiency of the clustering analysis on the wheat varieties.above to the ranks of High-nitrogen efficiency,nitrogen efficiency,nitrogen inefficient in three categories.Then choose the inefficient efficient nitrogen Zhoumai 16 and wheat varieties Yumai 49-198,research two different types of wheat in plant nitrogen concentration,group dynamics,the change of the respect such as dry matter accumulation and yield under the five nitrogen levels(pure nitrogen 0,120,180,240,360 kg hm2),wheat nitrogen dilution curve model is established and the nitrogen nutrition index model,analyzed the nitrogen nutrition index and relative stem base of nitrate,the relationship between the relative biomass and relative production.Explore using wheat critical concentration dilution model to assess degree of wheat plant nitrogen loss and the feasibility of the diagnosis of total nitrogen content of wheat plant height.The main results were as follows:The amount of dry matter accumulation of wheat growing along with the advancement of the growth period of wheat,jointing stage to booting stage increased the fastest.10 genotypes of wheat population is reduced after the first increased trends,and reached the maximum in reviving period.10 genotypes of wheat plant nitrogen content during the reproductive period with the development of growth period were reduced after the first increase trend,132 d after wheat seeding(green)to achieve the highest.10 genotypes of wheat plant stem nitrogen during the reproductive period with the development of growth period are showed a trend of reduced gradually;Leaf nitrogen content increase after first reduce trends,132 d after wheat seeding(green)to achieve the highest;Each period of wheat stem base showed a trend of increase after the first reduce the nitrate content,after jointing stage stem base nitrate content increased,this is because the jointing stage topdressing nitrogen caused by.According to the nitrogen utilization ability of all genotypes of wheat after clustering analysis,divided into nitrogen efficient Huaimai28,Yumai49-198,Taixue12,Pingan8,Wenmai19;Nitrogen effect Longping1301,Fengdecun1;inefficient Nitrogen efficient varieties Longping1302,Longping9987,Zhoumai16.Based on the selected Yumai 49-198,the inefficient nitrogen Zhoumai16 and conduct the thorough research to the two wheat varieties.Two genotypes of wheat aboveground biomass increased with the increase of n application rate increased N180,N240 and no significant difference between N360 processing,but were significantly higher than that of N0 and extended treatment.And meet the statistical sense of inequality DM0 < DM120 < DM180= DM240 = DM360.And critical nitrogen concentration of wheat aboveground biomass accords with power function relationship,through the regression estimate standard error analysis and the simulation value and real value is found that the linear relations between the simulation value and has the high alignment between the real value.Critical nitrogen concentration dilution curve model has good stability,and between the annual curve can be used as nitrogen nutrition diagnosis.Where the upper biomass growth,wheat showed a trend of increasing critical nitrogen uptake,and with the increase of dry matter,the critical nitrogen uptake increased gradually slow down.According to the nitrogen absorption model found two wheat varieties n application rate of 180 kg/hm2 is suitable.Two varieties of nitrogen nutrition index rises with the increase of n application,with the advance of wheat growth period degrees of fluctuations,and 2 years changing trends are basically identical.In the whole growth period of wheat,N0 extended treatment of nitrogen nutrition index is below1,show that the restriction of the nitrogen plant;N240,N360 treatment of nitrogen nutrition index greater than 1,show that sufficient nitrogen supply;And N180 treatment of nitrogen nutrition index fluctuated near1,showed that n application is appropriate.Two wheat varieties were characterized by two years with the increase of n application rate,yield increased significantly,however,when the n application rate reaches a certain number the production did not increase with the increase of n application.Two relatively stem base nitrate as nitrogen nutrition index increase gradually increase,in addition to Yumai 49-198 over-wintering stage and jointing stage relative stem base of nitrate and the fit of the nitrogen nutrition index was not significant,other all reached extremely significant level;The relatively dry matter accumulation of two wheat varieties to grow along with the NNI increase gradually,and with the NNI equation determination coefficient(R2)reached extremely significant level;Two relative yield of wheat varieties is with the increase of NNI increased after the first reduce the trend,and the NNI of Yumai49-198 reached 1.05 and 1.05,RY to obtain maximum,ZM16 NNI is 0.92 and 0.95,RY to obtain maximum.Visible,through N nitrogen nutrition index to evaluate wheat plant nitrogen nutrition status is correct and feasible.