Nitrogen Application Technology For High Yield And Good Quality In Springness Wheat Yangfumai 4 Following Rice

Wheat is one of the main grain crops in China. It is urgent to solve the problems in the production of wheat to reduce the amount of nitrogen application and increase the efficiency of nitrogen use in the premise of improving the yield. This study was conducted on the Experimental Farm of Jiangsu Provincial Key Lab of Crop Genetics and Physiology during the two wheat growing seasons from 2013 to 2015. Yangfumai 4, a medium-gluten wheat variety, was used as the tested variety. From three different technical approachs which were late-uptaking the ratios of nitrogen application and the time of fertilization and change the type of fertilizer, this study was conducted to research the effects of reduce the amount of nitrogen application and different stages of nitrogen fertilization to grain yield, the characteristics of nitrogen uptake and utilization and physiological basis, to clarify the optimal nitrogen application model, and to provide theoretical basis and technical support for the high yield and high efficiency of wheat. The main results were as follows:1. In contrast to the normal nitrogen application 240kg/hm2, reduce the amount of nitrogen application to 180kg/hm2, the grain yield decreased, but were similar with the yield levels of the 330kg/hm2 nitrogen application, indicating that a modest reduction of nitrogen application can achieve higher levels of yield; By the cultivation measures of late-uptaking the nitrogen fertilizer, the grain yield of the lower application amount of nitrogen and the ratios of nitrogen application was 5:1:2:2 was slightly higher than the normal amount of nitrogen application and the the ratios of nitrogen application was 5:2:3:0, which explained that reasonable nitrogen application under the condition of reducing nitrogen fertilizer can promote the improvement of the yield level.2. Yangfumai 4 with grain yield above 8500kg/hm2, the rate of tillers were 48% above, the maximum LAI were between 6.2～6.6, the dry matter production after anthesis were more than 6600kg/hm2 and the economic index were maintain above 0.46.Reduce and late-uptaking the nitrogen fertilizer, which was low nitrogen 180kg/hm2 and the ratios of nitrogen application was 5:1:2:2, the rate of tillers and the LAI increased at the stage of middle growth, was able to produce more photosynthate, and improve the post anthesis dry matter accumulation and translocation ability, on the basis the number of grains per spike and 1000-grain-weight stability, improve the spike number, thereby maintaining a relatively high yield.3.The net photosynthesis rate of flag leaf after flowering, the stomatal conductance and the transpiration rate showed a trend of decline over the growth process, presented rising trend; After flowering, the flag leaf SOD, CAT and POD activity showed first increased and then decreased curve change, MDA content with the developmental process went on gradually increased. Reduce and late-uptaking the nitrogen fertilizer, the degree of the net photosynthesis rate of flag leaf after flowering, the stomatal conductance and the transpiration rate decline slowed, the ascending rate of intercellular carbon dioxide concentration rising rate decreased, namely improved wheat photosynthetic rate under low nitrogen condition, prolonged photosynthetic time, and produced more photosynthetic products; and the activity of flag leaf SOD, CAT and POD increased, reduce the content of MDA, thus delayed the wheat flag leaf senescence under low nitrogen condition, and laid a foundation for yield improvement.4. Yangfumai 4 with grain yield above 8500kg/hm2, the NHI were between 0.71-0.74, and the amount of nitrogen output after flowering in vegetative organs were 105-113kg/hm2.With the increase of the amount of nitrogen fertilizer nitrogen productivity showed a downward trend on the whole; nitrogen use efficiency under the same nitrogen application ratio, with the increase of amount of nitrogen fertilizer decreased, under the same nitrogen application, when the ratios of nitrogen application were 5:1:2:2, the nitrogen use efficiency were the highest. When the nitrogen application were 240kg/hm2, the nitrogen application ratio were 5:1:2:2, the yield were the highest, and the nitrogen agronomic efficiency were 18.65kg/hm2 and 19.61kg/hm2 respectively. Reduce and late-uptaking the nitrogen fertilizer, nitrogen accumulation, nitrogen productivity, NHI, nitrogen use efficiency and nitrogen agronomic efficiency of wheat increased, promoted the absorption and utilization of nitrogen. With the decrease of the amount of nitrogen fertilizer and the late-uptaking the nitrogen fertilizer, the efficiency of nitrogen translocation to grain transport was improved, and the yield was maintained.5. Application of the new type of compound fertilizer, yield increased, but not reached the significant level, yield increase was mainly through the 1000-grain-weight increased, but the spike number decreased slightly, so in wheat production should note through appropriate reasonable combination of density and fertilizer to achieve suitable spike number, to ensure high yield, and its increasing production potential and mechanism,ecological effects remain to be further in-depth study.6. Under the condition of this experiment, Yangfumai 4 reached grain yield more than 9000 kg/hm2, should taken the new type of compound fertilizer Lv Ju-neng Fertilizer, and the nitrogen application were 240kg/hm2, the ratios of nitrogen application were 5:1:2:2; grain yield above 8500kg/hm2, general compound fertilizer was enough but the nitrogen application were 240kg/hm2, the ratios of nitrogen application were 5:1:2:2; grain yield above 7500kg/hm2, the amount of nitrogen application could be reduced to 180kg/hm2,taken the general nitrogen fertilizer and the ratios of nitrogen application were 5:1:2:2 or 3:1:3:3.