不同氮肥种类和亏缺灌溉对切花百合品质的影响

【目的】 氮素营养和土壤水分是影响百合切花生长和品质的重要因素。本研究进行了不同氮肥配比和灌溉量对百合生长、切花期、切花观赏品质、瓶插寿命和瓶插期间叶片和花被片生理指标的影响，以期为百合切花生产的水氮管理提供科学依据。【方法】 以东方百合‘索邦’为材料，在施氮（N）量相同情况下，盆栽试验设5种氮素处理，即单施尿素，单施铵态氮肥，单施硝态氮肥，铵态氮:硝态氮（50%:50%）、尿素氮:硝态氮（50%:50%）；2个灌水水平，即正常灌溉（苗期土壤含水量保持在60%~70%θ_f和现蕾期后70%~80%θ_f，θ_f是田间持水量）和亏缺灌溉（苗期土壤含水量保持在50%~60%θ_f和现蕾期后60%~70%θ_f）。在百合停止生长后，测定了株高和茎粗、花朵数量、花径、瓶插寿命，开花第7天和第14天百合叶片和花被片中可溶性糖、可溶性蛋白和丙二醛含量。【结果】 铵态氮肥与硝态氮肥配施处理百合株高最高，花朵数量最多，切花瓶插寿命最长，开花第7天和第14天叶片和花被片中可溶性糖和可溶性蛋白含量较高，并缓解叶片和花被片中的丙二醛积累。与正常灌溉相比，亏缺灌溉对百合株高、花朵数量、花径、切花瓶插寿命以及开花后叶片和花被片中的丙二醛、可溶性糖和可溶性蛋含量的影响因不同氮肥处理而异。在两种灌水水平下，单施尿素、尿素和硝态氮肥配施以及铵态氮肥和硝态氮肥配施处理切花期分别为100 d、90 d和85~86 d。在正常灌溉条件下，单施铵态氮肥和单施硝态氮肥切花期差异不大，为85~86 d；而在亏缺灌溉条件下，单施硝态氮肥切花期为91 d，而单施铵态氮肥为87.5 d。【结论】 硝态氮肥和铵态氮肥配施可以提高百合株高和花朵数量，缩短百合切花期，延长切花瓶插寿命，从而提高百合切花品质。而亏缺灌溉对百合切花质量的影响因不同氮肥处理而异。

Effects of different nitrogen fertilizers and deficit irrigation on quality of lily (Lilium spp.) cut-flower

Objectives] Nitrogen nutrition and soil moisture are important factors affecting the growth and quality of lily (Lilium spp.) cut-flowers.Different nitrogen fertilizers and irrigation volumes were tested in order to provide scientific basis for water and nitrogen management of lily cut-flowers.Methods] Taking Lilium spp.cv.Sorbonne as plant material,a pot experiment had been designed with five nitrogen fertilizer treatments:only ammonium-nitrogen,only urea,only nitrate-nitrogen,both ammonium and nitrate nitrogen (50％ ∶ 50％) and both urea and nitrate-nitrogen (50％ ∶ 50％) under the same N amount,and two watering levels,normal irrigation (soil water content was kept at 60％-70％ θf during the seedling stage and 70％-80％ θf after the squaring stage,θf is field capacity,W 1) and deficit irrigation (soil water content was kept at 50％-60％ θf during the seedling stage and 60％-70％ θf after the squaring stage,W2).Plant height and stem diameter after lily growth stopping,flower number,flower diameter,vase life,and the contents of soluble sugar,soluble protein and malondialdehyde (MDA) in leaves and tapels at 7 and 14 days after the flowering were respectively determined.Results] The combined application of ammonium-and nitrate-nitrogen fertilizers had higher plant height,larger flower numbers,longer vase span of cut-flowers and higher contents of soluble sugar and soluble protein in leaves and tapels,and less accumulation of MDA at 7 and 14 days after the flowering.Compared to the normal irrigation,the effects of the deficit irrigation on plant height,flower number and diameter,vase span of cut-flowers and the contents of soluble sugar,soluble protein and MDA in leaves and tapels after the flowering varied with different nitrogen treatments.In addition,different water and nitrogen treatments had different cut-flower periods.Under the two watering levels,the cut-flower periods were 100 d in applying only urea,90 d in the combined application of urea and nitrate-nitrogen fertilizer and 85-86 d in the combined application of ammonium-and nitrate-nitrogen fertilizers.Under the normal irrigation,the cut-flower periods were 85-86 d in applying only ammonium-or nitrate-nitrogen fertilizers.But under the deficit irrigation,the cut-flower periods were 91 d in applying only nitrate-nitrogen fertilizer and 87.5 d in applying only ammonium-nitrogen fertilizer.Conclusions] Under the condition of this study,the combined application of ammonium-and nitrate-nitrogen fertilizers is favorable to high plant height and flower numbers,shorten the cut-flower period and prolong the vase span of cut flowers,thus improve the quality of cut-flowers.The effects of the deficit irrigation on the quality of cut-flowers depends on nitrogen fertilizer form.