适度水分亏缺管理提高青稞营养品质和环境效益

摘要

[Objectives] The shortage of water resources in the Qinghai-Tibet Plateau affects the yield of hulless barley,however,it is still unclear about the extent of impaction on yield components and grain quality.This paper studied the impact of different water supply conditions,aimed at providing a theoretical basis for high efficient cultivation of hulless barley.[Methods] Using hulless barley cultivar Kunlun 14 as the tested materials,a field experiment with random blocks design was conducted in a shelter.Three water supply treatments of adequate (75％ field water capacity),mild water deficit (50％ field water capacity) and severe water deficit (25％ field water capacity) were designed.The yield components,and nutrition qualities including contents of NPK,protein and amino acids in grain were determined.[Results] Compared with adequate water supply treatment,water deficit significantly reduced the number of ears per hectare,spike length,grains per spike,yield,tiller numbers,plant height.Mild water deficit significantly reduced the number of ears per hectare and the number of grains per spike,while severe water deficit significantly reduced the three factors of yield components.Under water deficit,the contents of nitrogen,potassium,protein and total amino acid in hulless barley grain were all increased,and severe water deficit exaggerated the effect.The contents of phosphorus,essential and nonessential amino acids of grain were significantly higher under severe water deficit than under adequate water supply.[Conclusions] Mild water deficit is conducive to the root growth of hulless barley,and contributes to accumulate more protein and amino acids in grain.Therefore,appropriate irrigation should be further studied for saving water resources and reducing agricultural costs,and high quality ofhulless barley products.%[目的]针对青藏高原水资源短缺会降低青稞产量,但对产量构成和籽粒品质特性的影响尚不明确的问题,研究不同水分供应对青稞籽粒产量构成以及营养品质的影响,为青稞合理高效栽培管理提供理论依据.[方法]以昆仑14号为供试品种,进行了随机区组田间试验.设计灌溉至田间持水量的75％(充分灌溉处理)、50％(水分轻度亏缺处理)和25％(水分重度亏缺处理) 3个水平.调查了青稞根系、产量和籽粒NPK、蛋白质和氨基酸含量.[结果]水分亏缺显著降低青稞公顷穗数、穗长、穗粒数、产量、分蘖数、株高,且降幅随水分亏缺程度的加剧而增大.水分亏缺致使青稞产量显著降低,但不同亏缺程度对产量三因素的影响存在一定差异.水分轻度亏缺使公顷穗数和穗粒数显著降低,重度亏缺使产量三因素均显著降低.水分亏缺下青稞籽粒中氮、钾、蛋白质和总氨基酸的含量均呈升高趋势,且随着水分亏缺程度的加剧而进一步增加.重度亏缺处理青稞籽粒中磷含量、必需和非必需氨基酸含量均比充分灌溉显著升高.[结论]水分轻度亏缺有助于促进青稞根系生长,重度亏缺则会严重抑制根系生长.水分亏缺不利于青稞穗部的生长发育,导致其产量显著降低,却有利于籽粒中蛋白质及其组分含量的提高.适度亏缺灌溉不仅能节约水资源和降低农业成本,且该灌溉方式下青稞产量和籽粒中养分、蛋白质及其组分的含量均较高,为较佳的灌溉制度.