Effects Of Nitrogen Ratio Of Basal To Topdressing On Grain Yield And Physiological Regulation

In order to explore the effect of nitrogen application on grain yield and nitrogen uptake and utilization, and research the regulate and control by the plant growth regulators (PGRs), field experiments were conducted in Jingpu during 2012-2013 to explore the effect ofratio of basal to topdressing and Jinfeng on grain yield, group structure, photosynthetic produce characteristics and nitrogen utilization efficiency. The main results were as follows:1. The effects on grain yield formation, nitrogen uptake and utilization of wheat from different nitrogen application. It is beneficial for the grain yield when the topdressing ratio was increased to 60%. The grain yield is higher when the topdressing applied at jointing than booting under the condition of the base fertilizer at the same level. Increasing the share of topdressing ratio can enhance the content of SPAD and the activity of SOD, POD of flag leaf, the content of MDA decreased obviously at the same time. Thus help to delay senescence of leaf. The increasing of topdressing ratio is also profitable for the activity of NR and GS, what is more, it has a positive function on the nitrogen uptake efficiency, nitrogen agronomy efficiency and nitrogen harvest index.2. The effects on grain yield formation and nitrogen uptake and utilization of wheat by Jinfeng. The kernels per spike and thousand seed weight increased when the topdressing ratio was increased to 40% at booting, thus is beneficial for the grain yield of Nannong0686 and Huaimai33, the content of SPAD and the activity of SOD of flag leaf increased at the same time. It help to enhance the photosynthetic characteristics when the topdressing ratio was increased at booting. Jinfeng has a positive role in the activity of NR and GS, which is conducive to the nitrogen uptake efficiency, nitrogen agronomy efficiency and nitrogen harvest index.To sum up, the adjustment function of nitrogen application and the PRGs can change the photosynthetic characteristics and delay the senescence of flag leaf, which Has a positive promotion in the grain yield and nitrogen uptake and utilization. In this study, the nitrogen application at the level of 4:4:2 can make the most reasonable components of yield, and we can obtain the highest yield in these conditions. In addition, Spraying Jinfeng in the heading stage can be further improved the yield and nitrogen uptake efficiency of wheat.