Effcets Of Different Nitrogenous Fertilizer To Photosynthesis And Yield In Maize

Nitrogen is one of the most important decisions of photosynthetic material production capacity of maize.Clarifying under different nitrogen condition,different cultivars of maize photosynthetic physiological indexes and yield changes in the law,revealing cultivars differences of low nitrogen tolerance can provide a scientific basis for concentrate fertilization and cultivate low nitrogen tolerance cultivars of maize.The experiment carries on the crops demonstration garden of northwest A&F University on 2007.The experiment selects six different corn cultivars,including ZD958,XY335,JK28, SD8806,SD6615 and SD902.ZD958,XY335,SD8806s' tolerance to low nitrogen fertilized are better than JK28,SD6615 and SD902.Studied has been executing on the rule of six cultivars' photosynthesis characteristic and yield change under different nitrogen level,the result is as follows:(1)Under high nitrogen condition the difference of the height,the numbers and area of leaf between different cultivars is not significant;but there are significantly decreased under low nitrogen condition.JK28,SD6615 and SD902 have a more decreased than ZD958, XY335,SD8806,and it is significant.(2)Under high nitrogen condition the difference between six cultivars is not significant, but under low nitrogen condition,the dry matter accumulation of six cultivars between two nitrogen condition have a significant difference.The dry matter yield's change of ZD958,XY335,SD8806 between two nitrogen condition do not has a significant difference, but the dry matter yield's change of JK28,SD6615 and SD902 between two nitrogen condition has a significant difference.Comparison between six cultivars' dry matter yield under low nitrogen condition,we can found that the difference between ZD958,XY335, SD8806 and JK28,SD6615,SD902 is significant.(3)Under nitrogenous fertilizer full supply condition,the difference of the photosynthetic rate,transpiration rate,water use efficiency and stomatal conductance between six cultivars is not significant,but When the nitrogenous fertilizer supply level is low, the photosynthetic rate,transpiration rate,water use efficiency and stomatal conductanceis of different cultivars have a significant difference.The cultivars for tolerance to low-nitrogen including ZD958,XY335 and sd8806 can maintenance a relatively higher photosynthetic rate and photosynthetic duration.The cultivars of JK28,SD6615 and SD902 can not maintenance a relatively higher photosynthetic rate and photosynthetic duration,and there is significant difference between different cultivars.(4)Under high nitrogen condition the difference of the productivity per plant and the yield between different cultivars of maize is not significant.But under low nitrogen condition the difference of the productivity per plant and the yield between different cultivars of maize is significant.Compared with six cultivars' yield and productivity per plant under the low nitrogen condition,JK28,SD6615 and SD902 have a little difference to the high nitrogen condition.