通过探究水分调亏对河西地区膜下滴灌菘蓝(Isatis indigotica)各项生理指标、产量和水分利用的影响, 为菘蓝高效节水种植提供理论指导。于2016年在河西走廊中部张掖市民乐县益民灌溉试验站进行菘蓝水分调亏研究, 在保持苗期和肉质根成熟期充分灌溉的情况下, 在菘蓝营养生长期和肉质根生长期分别进行轻度、中度和重度的水分亏缺处理, 并测定各项光合生理指标、产量和水分利用率。结果表明, 营养生长期和肉质根生长期的中度与重度水分亏缺显著降低了菘蓝叶片净光合速率、叶面积指数、株高及主根长, 并且随水分亏缺程度加重降幅增大; 而轻度水分亏缺与对照组的差异不显著。营养生长期和肉质根生长期轻度水分亏缺处理的菘蓝产量与水分利用效率最高, 分别达到8 239.56 kg·hm^-2和24.11 kg·hm^-2·mm^-1; 其它水分亏缺处理组产量和水分利用效率均有所降低, 与对照组之间差异显著(P<0.05), 重度水分亏缺处理各项指标均最低。因此, 最优的菘蓝水分调控处理为营养生长期和肉质根生长期的轻度水分调亏, 能够降低菘蓝耗水量, 提高水分利用效率且其产量不会降低。

A field experiment was conducted to test the effect of mulched drip irrigation under water deficit regulation on the physiological indexes, yield and water use in the Hexi region, which would provide theoretical guidance for efficient high efficiency water saving. We used experiments with Isatis indigotica in different amounts of irrigation and growth stages in the Yimin Irrigation District of Gansu Province in 2016. With seedling stage and fleshy root maturity stage under normal water conditions, we measured the physiological indexes yield and water use under mild, moderate and severe water deficit treatments in the vegetative and fleshy root growth stages. The leaf photosynthetic rate (P_n), leaf area index, plant height and root length of I. indigotica were significantly reduced by water deficit regulation in the vegetative and fleshy root growth stages, with greater decrease with aggravated water deficit degree, but the difference with mild water deficit treatments was not significant. The yield and water use efficiency of I. indigotica root with mild water deficit treatment were 8 239.56 kg∙hm^-2 and 24.11 kg∙hm^-2·mm^-1, respectively. With other water deficit treatments reduced, there were significant differences between the control group (P<0.05), severe water deficit treatment being the lowest. Thus, optimal water regulation is mild water-deficit treatment of vegetative and fleshy root growth stages to reduce water consumption, and improving the efficiency of water use does not reduce its production.