水氮互作对石羊河流域春小麦群体产量和水氮利用的影响

Interactive impact of water and nitrogen on group yield of spring wheat and use of water and nitrogen in Shiyang River Basin

【目的】探讨西北旱区春小麦最佳的水氮耦合形式。【方法】在甘肃石羊河流域绿洲区采用田间试验,研究不同生育阶段的水量分配以及氮肥处理对春小麦群体产量和水氮利用的影响。【结果】施氮量、拔节期和抽穗期灌水对干旱区春小麦的产量影响显著;施氮量168 kg/hm2,并于拔节期灌水90 mm、抽穗期灌水70 mm,小麦可获得较高的籽粒产量。水氮对小麦地上干物质累积量的影响与对籽粒产量的影响相似,但抽穗期灌水对地上干物质累积量影响不显著。在施氮量224 kg/hm2、抽穗期和灌浆期灌水均为50 mm的条件下,小麦可获得较高的收获指数。在生产中考虑提高小麦收获指数时,首先应保证较高的籽粒产量。分蘖期和灌浆期灌水均为30 mm时,小麦的水分利用效率高达2.424 kg/m3,但产量降低约45%。施氮量对小麦地上干物质和籽粒氮素累积量影响显著;拔节期灌水90 mm、施氮量168 kg/hm2时,小麦籽粒的氮素累积量最大。【结论】石羊河流域春小麦最优灌水施氮模式为:施氮量168 kg/hm2,全生育期灌水4次,拔节期灌水90 mm,分蘖期、抽穗期、灌浆期均灌水60 mm。

[Objective] This study was to explore the best coupling form of water and nitrogen in arid areas of northwest China. [Method] Field experiment was conducted in the oasis region of Shiyang River basin. The interactive impact of water and nitrogen on group yield of spring wheat and use of water and nitrogen was investigated. [Result] Nitrogen rate and irrigation in jointing and heading stage impacted on spring wheat yield remarkably. With nitrogen rate （168 kg/hm2）,irrigation （90 mm） in jointing stage,and irrigation （70 mm） in heading stage,spring wheat production was higher. The impact of water and nitrogen on dry matter accumulation was similar to the impact on grain yield, but the impact of irrigation in heading stage on dry matter accumulation was not distinct. Higher harvest index could be got with nitrogen rate （224 kg/hm2） ,irrigation （50 mm） in heading and filling stage. Higher grain yield should be guaranteed, when enhancing the harvest index. WUE achieved 2. 424 kg/m3 and yield reduced by 45 % when the irriga- tion in tillering and filling stage both were 30 mm. The impact of nitrogen rate on nitrogen accumulation of grain yield and dry matter was significant;nitrogen accumulation of grain came to maximum when nitrogen rate （168 kg/hm2） and irrigation （90 mm） were applied. [[Conclusion] The optimal model of irrigation and nitrogen rate of spring wheat in Shiyang River Basin presents nitrogen rate 168 kg/hm2 ,irrigation 90 mm in jointing stage and irrigation 60 mm in tillering,heading and filling stage.