不同灌溉方式下水氮供应对冬小麦水氮利用效率的影响OACSTPCD

[Objective]Irrigation and nitrogen fertilization are critical to maintaining agricultural production in most regions in China.The purpose of this paper is to investigate the effect of water-nitrogen coupling under different irrigation methods on water and nitrogen use efficiency by winter wheat in attempts to provide an optimal irrigation-fertilization for wheat production in Henan province.[Method]The experiment was conducted in a field with Jimai 22 variety used as the model plant.We compared two irrigation methods:wide furrow irrigation(F)and border irrigation(Q),each having three irrigation amounts by controlling the lower soil moisture for irrigation at 60%(W1),70%(W2)and 80%(W3)of the field capacity,respectively.For each irrigation treatment,there were three nitrogen fertilizations by applying 120(N1),220 kg/hm2(N2)and 320 kg/hm2(N3)of nitrogen.Using the measured data and genetic algorithm,we optimized the irrigation and nitrogen fertilization for jointly maximizing wheat yield,water use efficiency,nitrogen partial factor productivity,soil nitrogen residue and output-input ratio.[Result]① Irrigation method,the lower soil water content for irrigation and nitrogen application all had a significant effect on water use efficiency,nitrogen partial factor productivity of the wheat,as well as soil nitrate residue in the 0-100 cm soil and the wheat grain yield(P＜0.01).With the increase in nitrogen application and the lower soil water content for irrigation,the grain yield and water use efficiency of the wheat both increased first followed by a decrease.② Grain yield,water use efficiency and the net profit were maximum in F+W2+N2,reaching 9 686.93 kg/hm2,1.97 kg/m3 and 15 142.93 yuan/hm2,respectively,which were 44.71%,56.65%and 56.59%higher than those in F+W1+N1.[Conclusion]The optimal irrigation and nitrogen fertilization for winter wheat in the studied area are:wide ridge furrow irrigation with the lower limit for irrigation being 70%of the field capacity,coupled with 245.46 kg/hm2 of nitrogen application.