水氮耦合对绿洲灌区蒙古黄芪光合特性的影响

Effects of Coupling of Irrigation and Fertilizer Application on Photosynthesis Characteristicsof Astragalus membranaceus var. mongholicus in Oasis Irrigated Areas

目的:探寻不同水氮耦合配比对绿洲灌区蒙古黄芪开花期光合生理特性的影响。方法:2018年在"甘肃省农业工程技术研究院试验基地"开展大田试验,以一年生蒙古黄芪为供试材料,采用裂区设计,以灌水量(W1:3200 m3/hm2,W2:3600 m3/hm2,W3:4000 m3/hm2)做主区,施氮量(N0:0 kg/hm2,N1:50 kg/hm2,N2:100 kg/hm2,N3:150 kg/hm2)为副区,测定蒙古黄芪开花期的光合特征。结果:灌水量和施氮量的互作效应对开花期蒙古黄芪的净光合速率、蒸腾速率和叶绿素含量具有显著影响(P<0.05)。在蒙古黄芪生育期减量20%灌水(W1)条件下,N2(中施氮)处理的净光合速率、蒸腾速率和叶绿素含量(SPAD)较N0(对照)、N1(低施氮)和N3(高施氮)分别提高147.62%、16.84%、42.60%,61.37%、10.97%、53.21%和57.83%、13.97%、9.13%。表明生育期减量20%灌水与中施氮处理耦合能够显著提高开花期蒙古黄芪的净光合速率、蒸腾速率和叶绿素含量,增强蒙古黄芪开花期的光合作用。结论:在绿洲灌区,采用蒙古黄芪生育期减量20%灌水(3200 m3/hm2)与中施氮量(100 kg/hm2)组合的最优栽培模式,可为实现该区黄芪高产、优质水肥管理提供技术指导和理论支撑。

Objective:To explore the effects of different ratio of application irrigation and nitrogen management on photosynthetic physiological characteristics of Astragalus membranaceus var.mongholicus in oasis irrigated area.Methods:In 2018,field tests were carried out in the“experimental base of Gansu institute of agricultural engineering technology”.Using annual Astragalus membranaceus var.mongholicus as test material,split zone design was used to determine the photosynthetic characteristics of Astragalus membranaceus var.mongholicus at the flowering stage with irrigation water(W1:3200 m3/hm2,W2:3600 m3/hm2,W3:4000 m3/hm2)as the main area and nitrogen application(N0:0 kg/hm2,N1:50 kg/hm2,N2:100 kg/hm2,N3:150 kg/hm2)as the secondary area.Results:The interaction effect of irrigation and nitrogen fertilizer application amount had significant influences on the photosynthetic rate,transpiration rate and chlorophyll content of Astragalus membranaceus var.mongholicus at the flowering stage(P<0.05).Under the reduced 20%irrigation(W1)in growth stages of Astragalus membranaceus var.mongholicus,compared with the CK(N0),N1(low nitrogen application)and N3(high nitrogen application)treatments,the photosynthetic rate,transpiration rate and chlorophyll content with medium nitrogen application treatment was increased by 147.62%,16.84%,42.60%and 61.37%,10.97%,53.21%and 57.83%,13.97%,9.13%,respectively.The results showed that the coupling of reduced 20%irrigation and medium nitrogen application in growth stages could significant increase photosynthetic rate,transpiration rate and chlorophyll content,enhance the Astragalus membranaceus var.mongholicus photosynthesis at the flowering stage.Conclusion:In oasis irrigated area,the optimal cultivation mode of Astragalus membranaceus var.mongholicus with 20%irrigation(3200 m3/hm2)and medium nitrogen application(100 kg/hm2)can provide technical guidance and theoretical support for the high yield and high quality water and fertilizer management of Astragalus membranaceus var.mongholicus in this area.