Effects Of Nitrapyrin Application On Grain Yield And Nitrogen Efficiency Of Summer Maize

In 2014 and 2015, this study was conducted at experimental farm of Shandong agricultural university and crops research institute for agricultural economics of Mazhuang Town Tai'an City(35o59'N,117o00'E). Summer maize hybrid Denghai605(DH605) and Denghai618(DH618) were used as experimental material to study the effects of nitripyrin application on grain yield and nitrogen efficiency of summer maize.Experimental treatments include the amount of nitrogen fertilizer, nitrogen application methods, with or without nitrapyrin. This experiment aims to study the effects of nitrapyrin application on grain yield and nitrogen efficiency of summer maize. The main results as follows:1. Effects of nitrapyrin application on grain yield and its components of summer maizeNitrapyrin application can increase grain yield, yield increase of 0.7%-4.8%.Increasing yield effect of nitrapyrin application is different for different nitrogen application and different ways of nitrogen. Nitrapyrin application significantly increased production of one-time base N fertilizer processing, in the N1 level, and significantly increased yield of split application of N fertilizer in the N2 level.2. Effects of nitrapyrin application on nitrogen efficiency of summer maizeNitrogen fertilizer can increase plant nitrogen accumulation of summer maize, but the effects of different nitrogen application methods are different. Nitrapyrin application significantly increased plant accumulation after anthesis of nitrogen, and the proportion of N accumulation after anthesis were also significantly increased, as well as nitrogen uptake rate. Mature stage, nitrapyrin application significantly increased the amount of nitrogen accumulation of grain, mainly influenced by the amount of nitrogen assimilation after anthesis, significantly increased the plant amount of nitrogen assimilation after anthesis, while improving the efficiency of nitrogen utilization. Nitrapyrin application significantly increased partial factor productivity from applied nitrogen(PFPN)of summer maize, agronomic efficiency of applied nitrogen(AEN),agronomic efficiency of applied nitrogen(AEN), Nitrogen harvest index(NHI)also increased, significantly reduced soil nitrogen dependency rate(SNDR). Different nitrogen application methods on0-100 cm soil accumulation of nitrate and ammonium have different effects, but the overall trend is gradually decreased with the growth process of accumulation. Split application of N split changed the soil nitrate and ammonium nitrogen trends, soil nitrate and ammonium nitrogen accumulation increased rapidly, can topdressing nitrogen as needed, increasing nitrogen utilization efficiency. Agreement on 0-40 cm soil nitrate and ammonium content of nitrogen application with or without nitrapyrin, Nitrate content decreased, increased ammonium nitrogen, reduce nitrogen leaching, alleviate environmental pollution.3. Effects of nitrapyrin application on physiological characteristics of summer maizeNitrogen fertilization can significantly increase the amount of dry matter accumulation of summer maize plant. Nitrapyrin application increased dry matter accumulation of summer maize after anthesis, but did not reach a significant level.Nitrapyrin application remission leaf senescence, extend the function of leaves, and it isimportant to improve the photosynthesis of leaves.