混播比例对高寒草地红豆草−垂穗披碱草混播群落生物量分配与竞争的影响  

Effects of mixed seeding ratio on biomass allocation and competition of Onobrychis viciifolia and Elymus nutans under cold conditions in the Tianzhu alpine region

作　　者：任文 张志新[1,2] 蔺昶兴[1] 杨倩 沈禹颖[1] REN Wen;ZHANG Zhixin;LIN Changxing;YANG Qian;SHEN Yuying(College of Pastoral Agriculture Science and Technology,Lanzhou University/State Key Laboratory of Grassland Agro-ecosystems,Lanzhou University,Lanzhou 730020,Gansu,China;College of Grassland Agriculture,Northwest A&F University,Yangling 712100,Shaanxi,China)

机构地区：[1]兰州大学草地农业科技学院/兰州大学草地农业系统国家重点实验室,甘肃兰州730020 [2]西北农林科技大学草业与草原学院,陕西杨凌712100

出　　处：《草业科学》2020年第10期2035-2048,共14页Pratacultural Science

基　　金：国家牧草产业技术体系资助(CARS-34);甘肃省委组织部2019年重点人才项目。

摘　　要：混播是高寒地区栽培草地建植的重要方法。本研究于2018−2019年在天祝县进行大田试验,探究不同混播比例的红豆草(Onobrychis viciifolia)和垂穗披碱草(Elymus nutans)(100∶0、70∶30、50∶50、30∶70、0∶100)栽培草地的生长动态及种间关系的变化。建植第1年,混播群落生物量于生长季末期达到最大,当红豆草和垂穗披碱草混播比例为70∶30时,土地当量比(land equivalent ratio,LER)值较高,地上总生物量最大,为3172.2 kg·hm^−2,此时红豆草、垂穗披碱草间竞争关系较弱,两者竞争比率(competitive ratio,CR)值接近于1,混播群落的真实产量损失(actual yield loss,AYL)值接近于0或小于0。建植第2年,6月时混播群落绝对株高及自然株高较低,混播比例为30∶70的处理红豆草CR值、侵略强度(aggressivity,A)值大于垂穗披碱草,随着混播群落不断生长,红豆草、垂穗披碱草绝对株高及自然株高发生变化,生长空间趋于饱和,此时红豆草竞争能力(CR值、A值)远小于垂穗披碱草。第2年生长季末期,混播处理的LER值、AYL值分别为1.33~1.68和24.0%~57.0%,30∶70的处理生物量最大,为9178.8 kg·hm^−2,分别为红豆草单播、垂穗披碱草单播的3.6和1.6倍。综上,不同比例的红豆草与垂穗披碱草混播草地其产量及种间关系会随生长阶段的变化而变化,其中30︰70的组合在两年的生长季中总产量最高,应根据使用途径选择合适混播比例及时间段对其加以利用。Mixed seeding is an important method for establishing grassland in cold alpine regions.In this study,a field experiment using Onobrychis viciifolia and Elymus nutans mixed in different ratios(100∶0,70∶30,50∶50,30∶70,and 0∶100)was conducted from 2018−2019 in Tianzhu County to explore growth dynamics and inter-species competition.The results showed that the biomass of mixed communities reached a maximum at the end of the first growing season.The land equivalent ratio(LER)was relatively high and the aboveground biomass was larger(3172.2 kg·ha^−1)when the ratio of O.viciifolia to E.nutans was 70∶30.Competition between O.viciifolia and E.nutans was weak[the competitive ratio(CR)was close to 1]and the actual yield loss(AYL)of the community was close to,or less than 0.During the second year,the CR and aggressivity(A)of O.viciifolia was higher than that of E.nutans because the absolute and natural heights were low in June.As community growth continued,the absolute and natural heights changed consistently so that the growth space tended to be filled.The competitive strength of O.viciifolia(CR,A)was different from that of E.nutans during this stage.The range of LER was 1.33~1.68 and the AYL was 24.0%~57.0%.The biomass of the 30∶70 ratio was 9178.8 kg·ha^−1 and was the highest of all the treatments,being equivalent to 3.6 times that of O.viciifolia and 1.6 times that of E.nutans when grown alone.The mixed grassland with different ratios of O.viciifolia and E.nutans performed differently at different growth stages.The total biomass of the two growth seasons was highest when the planting ratio was 30∶70.The ratio of mixing for grassland seeding should be adopted based on demand.

关 键 词：高寒地区 栽培草地 生物量分配 竞争指数 

分 类 号：S541.4[农业科学—作物学] S543.9