施氮及豆-禾混播对草地群落及土壤呼吸的影响  

Impacts of nitrogen application and legume-grass mixed planting on grassland community and soil respiration

作　　者：唐雪娟 徐丽君[1] 逄焕成[1] 杨云卉[1] 王笛 李达 白可喻[1,2] 

机构地区：[1]中国农业科学院农业资源与农业区划研究所,北京100081 [2]国际生物多样性中心东亚办事处,北京100081

出　　处：《生态学杂志》2018年第3期831-839,共9页Chinese Journal of Ecology

基　　金：国家重点基础研究计划项目(2015CB150803);国家重点计划研发项目(2016YFC050050303);现代农业产业技术体系建设专项资金(Cars-34);中央级公益性科研院所基本科研业务费专项(647-53)资助

摘　　要：豆-禾混播是提高水土资源保持和利用效率、抑制土地退化和维持土壤健康的重要栽培措施。本实验以紫花苜蓿(Medicago sativa)、无芒雀麦(Bromus inermis)、羊草(Leymus chinensis)、紫花苜蓿+无芒雀麦、紫花苜蓿+羊草5种不同类型的人工草地为研究对象,以施氮水平为辅因素,通过对地上生物量、光合特性和土壤呼吸强度的比较研究,探明施氮条件下豆-禾混播草地群落动态及土壤呼吸日变化特征,以期为内蒙古东部地区人工草地合理建植与利用提供理论依据。结果表明:与苜蓿单播和羊草单播的生物量相比,混播对提高草地总体的生物量效果不显著;与苜蓿混播能在不同程度上提高禾本科牧草的净光合速率,其中无芒雀麦提升效果显著,3种牧草单播的净光合速率表现为紫花苜蓿<无芒雀麦<羊草;施氮提高了不同建植方式下人工草地的平均土壤呼吸强度;与苜蓿混播能显著提高禾草草地的土壤呼吸强度,且最高点一般出现在10:00—12:00。Legumegrass mixed planting is an important way to improve conservation and useefficiency of water and soil resources, restore degraded land, and maintain soil health. Five types of pastures （Medicago sativa, Bromus inermis,Leymus chinensis, M. sativa and B. inermis mixed planting, andM. sativa and L. chinensis mixed planting） were established in HulunbuirGrassland Station, with different nitrogen fertilization levels being applied. Aboveground biomass,photosynthetic characteristics and soil respiration were measured, aiming to understand the impacts of nitrogen application and legumegrass mixed planting on the characteristics of grassland community and the dynamics of soil respiration and thus provide theoretical basis for pastureestablishment and optimal utilization in eastern Inner Mongolia. Results showed that mixed planting did notsignificantly increase the total biomass of pasture as expected under drought condition. The netphotosynthetic rate （Pn） of the three species was in the order of：M. sativa 〈B. inermis〈L. chinensis. Mixed sowing with alfalfa significantly improved the Pn of grasses. Nitrogen application increased the soil respiration intensity under each planting type. Moreover, mixing with alfalfa improved soil respiration intensity, with perk values occurring at 10：00-12：00.

关 键 词：混播 施氮 地上生物量 土壤呼吸 

分 类 号：S812[农业科学—草业科学]