Effects Of Nitrogen Application Schemes On The Growth And Nitrogen Use Efficiency Of Super-yield Spring Maize

Effects of nitrogen application schemes on the growth and nitrogen use efficiency of super-yield spring maize were studied by the methods of field experiment on a farm of Inner Mongolia University for Nationalities located in the plain of West Liao river in2010. The results showed that:Opt N treated condition had relatively larger leaf area index, light orientation voltage and smaller leaf angle compared with other treatment. Content of leaf chlorophyll,Opt N treated condition had relatively higher between nitrogen treatment. Net photosynthetic rate. transpiration rate, stomatal conductance and photosynthetic capacity in plant of spring maize with the lapse of the growth period appeared as increased first and decreased afterwards that silking stage reached the maximum of each index. Net photosynthetic rate, transpiration rate, stomatal conductance and photosynthetic capacity in plant with the Opt N treated condition of the highest, the CK of the lowest and the others are between them at different growth stages. The light energy utilization of instantaneous and water use efficiency of instantaneous with the Opt N treated condition of the highest, the CK of the lowest. By the influence of the net photosynthetic rate, the amount of Leaf source capacity to order for treated condition of Opt N,130%Opt N,70%Opt N, H N and CK.The dry matter accumulation(y)of unit area accorded with Logistic curve equation of y=k/(1+a×exp-bx) to the number of days (x)after seedling growth process between nitrogen treatments. The correlation coefficient all reached significant.The max accumulation rate to Opt N treated condition was the biggest, respectively from130%Opt N,70%Opt N, H N and CK were higher by7.18%,10.70%,19.51%and35.91%. Each organs assimilate transportation efficiency of aboveground Opt N treated condition was all the greatest. Root dry weight with the lapse of the growth period appeared as increased first and decreased afterwards that silking stage reached the maximum. At different growth stages the root dry weight of Opt N treated condition was maximum between nitrogen treatment. The root dry weight accumulation (y) of unit area accorded with quadratic curves of y=c+bx-ax2to the number of days (x)after seedling growth process between nitrogen treatment. The content of nitrogen in maize plant between nitrogen treatments, silking stage were higher than physiological maturity,both silking stage and physiological maturity has the maximum when treated with130%Opt N and the secondary by using Opt N while the lowest when using CK. Both silking stage and physiological maturity the nitrogen accumulation of plant, Opt N treated condition were all the biggest; Nitrogen physiology efficiency has the maximum when treated with CK, and the secondary by using70%Opt N, while the lowest when using Opt N. With the increase of levels of nitrogen application, the nitrogen physiology efficiency generally decreased.Nitrogen utilization efficiency overall performance for low nitrogen level was higher, high nitrogen level was lower; Nitrogen harvest index with the Opt N treated condition of the highest, the130%Opt N of the lowest; The absorption of nitrogen has the highest when treated with Opt N, and the secondary by using130%Opt N, while the lowest when using70%Opt N in the seeding-silking stage and silking stage-physiological maturity. Rate of nitrogen fertilizer physiological utilization, nitrogen fertilizer efficiency and nitrogen fertilizer absorbing efficiency all decreased with the increasing of levels of application. Rate of nitrogen fertilizer utilization was highest when treated with Opt N, and the secondary by using70%Opt N, while the lowest when using H N.Spring maize has the hightest yield when treated with Opt N(15.18t/hm2), respectively from130%Opt N,70%Opt N, H N and CK were higher by6.83%,11.54%,11.70%and46.24%.The results showed that:Super-yield maize had stronger photosynthetic capacity, greater dry matter accumulation and assimilate transportation efficiency, higher yield and nitrogen use efficiency under Opt N treatment, which was the best nitrogen fertilizer management mode for super-yield maize in the plain of West Liao river.