Effects Of Nitrogen Application Techniques On Grain Yield And Quality In Winter Wheat

The experiments were conducted from 2005 to 2006 at the farm of Henan Agricultural University.Aizao8 and Zhoumai18,two typical cultivars of high-yield and mid-gluten were used in this study.Field culture method was applied in the experiment.From soil-winter wheat plant system of view,the effects of different nitrogen application amount (3 nitrogen rates from 180 to 300 kg·hm^-2)and three ratios of base and topdressing on the yield and quality of wheat.The main results were as follows:1.Nitrogen absorption,distribution,utilization of soil-winter wheat plant system.Comparison after-wheat-harvest with before-sowing,application of nitrogen fertilizer could increase content of total nitrogen in 0～100cm soil profile,but had no obvious difference among different nitrogen treatments.Available nitrogen content increased obviously in 0～60cm soil layer at the middle and latter part of wheat growth stage with nitrogen rates increasing,but nitrogen application can't affect available nitrogen content obviously in 60～100cm soil layer.The content of total nitrogen of wheat plant before anthesis could be increased with the mount of basal nitrogen fertilizer increasing.The content of total nitrogen of wheat plant at anthesis could be increased with using basal nitrogen and jointing nitrogen.Using booting nitrogen could increase the content of total nitrogen of wheat plant of aizhao8 at milky-type,but had little effect on zhoumai18.The increment of nitrogen fertilizer dosage and ratio of topdressing was propitious to the transport of nitrogen from wheat plant to grain and increased the nitrogen level of grain for Aizao8 from 180 to 300kgN/hm² nitrogen fertilizer dosage.For Zhoumai18,the highest nitrogen level of grain was gained with base nitrogen fertilizer and jointing at middle nitrogen fertilizer.2.Effects of nitrogen application on changes of NO₃^-- N content in 0～100cm soil profile with time and space.The content of fertilizer NO₃^-- N content in 0～40cm soil layer increased significantly with the increment of nitrogen fertilizer dosage and ratio of basal nitrogen fertilizer,but The content of fertilizer NO₃^-- N content in 40～100cm soil layer had no significant difference among the nitrogen application treatment at the forepart of wheat growth stage.The content of fertilizer NO₃^-- N content in 0～40cm soil layer lowered for treatment L1,M1,but that of treatment M3,H2,H3 showed redundant in 0～40cm soil layer at middle wheat growth stage.The content of fertilizer NO₃^-- N content increased significantly in 0～100cm profile with the increment of nitrogen fertilizer dosage,but that of had no significant difference for three ratios of base and topdressing at the same nitrogen fertilizer dosage at maturity.The content of fertilizer NO₃^-- N content of depth layer was higher than that of flat layer especially under the high nitrogen fertilizer level.3.Effects of nitrogen application of the ability of cold resistance.At winter,the content of soluble sugar lowered with the increment of nitrogen fertilizer dosage and ratio of basal nitrogen fertilizer,but index of cold injury increased. The coefficient of index of cold hurt and content of soluble sugar showed significant negative correlative.The index of cold hurt and activity of wheat root showed significant plus correlative.4.Effects of nitrogen application on the ability of lodging resistance.The length of the first,second internode and the total nitrogen of the second internode increased with the increment of nitrogen fertilizer dosage and basal nitrogen fertilizer ratio. The outside diameter and breastwork thick and node of stem of the first and second internode and the culm mechanical strength of the second internode showed contrary rule.The culm mechanical strength of the second internode showed significant plus correlative with the length internode and the outside diameter and the breastwork thick but significant negative correlative with the node of stem and the total nitrogen content.5.Effects of nitrogen application on wheat yield.Nitrogen application had obvious effects on grain yield.Compared with Aizao8, Zhoumai18 gained the higher yield.The highest yield of Aizhao8 is 8319.0kg·hm^-2,which gained from Treatment M1.The highest yield of Zhoumai18 is 9027.0 kg·hm^-2,which gained from treatment M2.Nitrogen application had effects on grain yield of Aizao8 through by spike numbers, but on grain yield of Zhoumai18 through by kernel numbers per spike and weight per 10³ kernels.6.Effects of nitrogen application on grain quality.The protein content of Aizhao8 increased with the increment of nitrogen fertilizer dosage and topdressing nitrogen fertilizer ratio and was 14.64%which gained fromH1.The protein content of Zhoumai18 was 14.29%which is gained from Treatment M2.Nitrogen application had obvious effects on the ratio of amylase to amylopectin,and the ratio increased with the increment of nitrogen fertilizer dosage and topdressing nitrogen fertilizer ratio.The development time and the stability time of Aizao8 extended with the increment of nitrogen fertilizer dosage and topdressing nitrogen ratio.The development time and the stability time of Zhoumai18 extended first and then shortened with the increment of nitrogen fertilizer dosage and topdressing nitrogen ratio.The mixing tolerance index and degree of softening showed contrary rule7.Ascertainment of the optimum nitrogen applicationFrom 180 to 300 kg N/hm²,treatment M1 was the optimum nitrogen application mode for Aizao8.For Zhoumai18,treatment M2 was the optimum nitrogen application mode. Two nitrogen application modes not only could decrease the possibility of nitrogen pollution to groundwater but also gained the best economy benefit.