灌溉与施氮对留茬免耕春小麦产量、水分利用效率及氮肥表观利用效率的影响

Effects of Irrigation and Nitrogen Supply on Grain Yield,Water Use Efficiency and Apparent Nitrogen Recovery Fraction of Spring Wheat on No-tillage Farmland with Standing Stubble

在甘肃省石羊河流域绿洲灌区,研究了不同灌溉量(常规灌溉327 mm、节水20%灌溉261 mm和节水40%灌溉196 mm)和施氮量(0、140、221 kg·hm-2和300 kg·hm-2)对留茬免耕春小麦籽粒产量、秸秆产量、收获指数、水分利用效率和氮素表观利用效率的影响。结果表明,在各施氮处理中,春小麦籽粒产量、秸秆产量、收获指数随灌溉量增加而增加,水分利用效率和氮素利用效率随灌溉量增加先增加后降低。节水20%灌溉的水分利用效率和氮素表观利用效率最高。就各灌溉水平平均值而言,当施氮达到221 kg·hm-2,春小麦籽粒产量(6365kg·hm-2)、收获指数(0.49)、水分利用效率(14.51 kg·mm-1.hm-2)和氮素表观利用效率(21.8%)达到最大值。在与该试验条件相似地区,综合考虑籽粒产量、水分利用效率和氮素表观利用效率,节水20%灌溉和221kg·hm-2施氮量为最优组合。

A controlled experiment was conducted in oases of the Shiyanghe river basin to investigate the effects of different irrigation and nitrogen supply levels on grain yield,straw yield,harvest index（HI）,water use efficiency（WUE） and apparent nitrogen recovery fraction（NF） of spring wheat on no-tillage farmland with standing stubble.A complete randomized block split-plot design was employed with different irrigation regimes,namely conventional irrigation of 327 mm,20% water-saving irrigation of 261 mm,40% water-saving irrigation of 196 mm,and nitrogen fertilizer application rates of 0,140,221,300 kg·hm-2,respectively.Under the experimental condition,the wheat grain yield,straw yield and HI increased with increase of the irrigation volume,and the WUE and NF increased at first and then decreased with the increase of the irrigation volume.The WUE and NF were the highest at 20% water-saving irrigation among different irrigation treatments.When the nitrogen supply level was 221 kg·hm-2,the grain yield of 6 365 kg·hm-2,HI of 0.49,WUE of 14.51 kg·mm-1·hm-2 and NF of 21.8% reached the maximum among different nitrogen treatments.Comprehensively considering for the grain yield,WUE and NF,the treatment of 20% water-saving irrigation combined with nitrogen supply level of 221 kg N·hm-2 was the best choice for wheat production in oases of the Shiyanghe river basin in Gansu Province on no-tillage farmland with standing stumble.