紫花苜蓿和垂穗披碱草混播种间关系对水分的响应  

Response of the Relationship between Mixed Sowing of Alfalfa and Elymus nutans to Water Content

作　　者：赵力军 寇潇雪 王铁梅[1,2] ZHAO Lijun;KOU Xiaoxue;WANG Tiemei(School of Grassland Science,Beijing Forestry University,Beijing 100083,China;Horqin Grassland Ecosystem National Observation and Research Station,Xingan League 137400,China)

机构地区：[1]北京林业大学草业与草原学院,北京100083 [2]内蒙古科尔沁草原生态系统国家定位观测研究站,内蒙古兴安盟137400

出　　处：《中国草地学报》2025年第2期80-90,共11页Chinese Journal of Grassland

基　　金：内蒙古自治区揭榜挂帅项目“优质苜蓿新品种选育及产业化示范”(2022JBGS0020)。

摘　　要：紫花苜蓿和垂穗披碱草混播是干旱半干旱地区人工草地建植的重要方式。为明确不同水分条件下这两种混播牧草的种间竞争关系,本研究设置土壤饱和持水量的80%(W1)、65%(W2)、50%(W3)、35%(W4)四个水分梯度水平,采用室内盆栽控水试验,分析两种牧草的种间关系对水分的响应。结果表明:在W4水分处理下,两种牧草水分利用效率降低;在W3水分处理下,垂穗披碱草的水分利用能力比紫花苜蓿强。水分亏缺降低了两种牧草的单株地下生物量和地上生物量,紫花苜蓿地上生物量对水分亏缺的响应更明显;两种牧草的根冠比均随土壤水分含量降低呈先减小后增大的趋势;两种牧草的株高在混播与单播处理间无明显差异。在W1和W3水分处理下,两种牧草存在竞争关系,紫花苜蓿竞争力弱于垂穗披碱草,且随土壤水分含量降低,紫花苜蓿竞争力减弱。The establishment of mixed alfalfa(Medicago sativa)and Elymus nutans represents a critical strategy for artificial grassland cultivation in arid and semi-arid regions.To elucidate their interspecific competition dynamics under varying moisture conditions,we conducted a controlled pot experiment with four soil moisture gradients:80%(W1),65%(W2),50%(W3),and 35%(W4)of saturated water holding capacity.The results showed that severe water stress(W4)significantly reduced water use efficiency(WUE)in both species,while E.nutans exhibited superior water utilization capabilities compared to alfalfa under moderate drought(W3).Water deficit reduced both aboveground and underground biomass of tow forages,with alfalfa showing greater sensitivity in aboveground biomass reduction.Both species displayed a characteristic root-to-shoot ratio pattern,initially decreasing then increasing with declining soil moisture.There was no significant difference in plant height between mixed sowing and single sowing treatments.There was a competitive relationship between the two herbages under W1 and W3 water treatment,and the competitiveness of alfalfa was weaker than that of E.nutans,and the competitiveness of alfalfa decreased with the decrease of soil moisture content.

关 键 词：紫花苜蓿 垂穗披碱草 水分胁迫 种间关系 

分 类 号：S54[农业科学—作物学]