Effect of Nitrogen Application on Yield,Quality and Fluorescent Characteristic of Late-sown Winter Wheat

In order to find out the efficient nitrogen management of late sown wheat for high yield and good quality in the Huaibei region,Jimai 22 was selected as field experimental material,and the effects of nitrogen application on grain yield,quality and fluorescent characteristic of winter wheat were studied.The results showed that,when fertilizing with nitrogen at jointing stage or booting stage,the light transmission rate was reduced,and the SPAD at filling stage,leaf area index at late growth stage were raised;meanwhile,the PSⅡ potential activity(Fv/Fo),the maximum photochemical efficiency(Fv/Fm)and actual photochemical efficiency of PSⅡ(ΦPSⅡ)were improved,which enabling flag leaves to absorb more light energy for photosynthesis.The improved photochemistry efficiency promoted the accumulation of dry matter and the percentage of earbearing tillers of wheat.Nitrogen management had significant effect on the yield of wheat.Among all the treatments,spike number per hectare and grain yield tended to be the highest under the treatment of topdressing nitrogen fertilizer at jointing stage and base to dressing ratio of 6∶4,and which increased the grain yield by 5.5%~10.8%.Postponing nitrogen application and increasing the ratio of base to topdressing could improve protein content,wet gluten content,sedimentation and hardness of wheat grains obviously.Under this experiment condition and total nitrogen fertilizer application of 270kg·hm-2,the treatments of topdressing nitrogen fertilizer at jointing stage and base to dressing ratio of 6∶4or at booting stage and base to dressing ratio of 4∶6were more rational.