不同豆禾混播比例对植物种间关系及草地生产力的影响  

Effect of sowing ratio on interspecific relationships between species and grassland productivity in legume-grass mixtures

作　　者：郭川 赵艳兰 李香君 周冀琼 刘琳[1] 孙飞达[1] 白彦福 马骢毓 GUO Chuan;ZHAO Yanlan;LI Xiangjun;ZHOU Jiqiong;LIU Lin;SUN Feida;BAI Yanfu;MA Congyu(College of Grassland Science and Technology,Sichuan Agricultural University,Chengdu 611130,Sichuan,China)

机构地区：[1]四川农业大学草业科技学院,四川成都611130

出　　处：《草业科学》2022年第11期2307-2316,共10页Pratacultural Science

基　　金：国家自然科学青年基金(31901379);四川省科技厅应用基础项目(2019YJ0431)。

摘　　要：选取西南山地丘陵区常见的4种豆禾牧草鸭茅(Dactylis glomerata)、多年生黑麦草(Lolium perenne)、白三叶(Trifolium repens)、红三叶(T.pratense),设置3个豆禾比例[5:5(L_(5)G_(5))、4:6(L_(4)G_(6))、3:7(L_(3)G_(7))]及4种草单播(DG、LP、BP、TP)共7个处理。通过在3和30 cm土层进行^(15)N同位素标定,分析不同混播比例下,由不同固氮潜力及根系深度植物构建的混播及单播群落的相对总产量、竞争强度、土地当量比、超产效应、补偿效应、选择效应、植物氮磷含量、固氮量和固氮率的异同,探究混播草地的生产性能及垂直生态位养分吸收策略,揭示高产稳定混播草地的维持机制。结果表明,相较单播,4种植物混播草地具有明显的超产优势,其中L_(5)G_(5)处理的地上生物量、相对总产量、土地当量比、超产效应和植物全磷含量最高;混播草地中较高的生产力主要受到补偿效应的影响。相较单播,L_(5)G_(5)混播草地中植物在土层3 cm的^(15)N吸收量及豆科固氮量均显著提升(P<0.05),L_(5)G_(5)混播植物在浅层3 cm土壤的氮素吸收量及豆科的固氮量显著高于在深层30 cm土壤(P<0.05)。本研究为西南地区多年生混播草地生产力提升提供了理论基础及技术支撑。In this study,four common legumes and grasses,Dactylis glomerata,Lolium perenne,Trifolium repens,and T.pratense,were selected to establish legume-grass mixture with their monocultures i.e.,DG,LP,BP,and TP,respectively,and three sowing ratios[5:5(L_(5)G_(5)),4:6(L_(4)G_(6)),3:7(L_(3)G_(7))];forming a total of seven treatments.^(15)N was used as a tracer to determine the effect of AM fungi on nutrient uptake from shallow(3 cm)and deep(30 cm)soil layers in both mixtures and monoculture treatments.The relative yield total,competitive intensity,land equivalent ratio,overyielding,complementarity,and selection effects,plant nitrogen and phosphorus content,the amount and rate of nitrogen fixation were determined to assess the production performance and vertical niche nutrient uptake strategy of legume-grass mixtures,and reveal the maintenance mechanism of high-yield and stable legume-grass mixture.The results showed that,compared with monocultures,the four plant species in legume-grass mixtures had significant overyielding advantage,and the L_(5)G_(5)treatment had the greatest shoot biomass,relative yield total,land equivalent ratio,overyielding effect,and plant total phosphorus content.The higher productivity in the legume-grass mixtures was mainly affected by the complementarity effect.Compared to monocultures,the^(15)Nuptake of plants and the amount of nitrogen fixation in the legume-grass mixtures were significantly increased(P<0.05).The nitrogen absorption and fixation amount from the shallow 3 cm soil were significantly higher than those from the deep 30 cm soil(P<0.05).The results of this study provide a theoretical basis and technical support for the productivity improvement of perennial mixed grassland in southwest China.

关 键 词：豆禾混播 超产效应 补偿效应 固氮量 氮磷吸收 生态位 种间竞争 

分 类 号：S812.4[农业科学—草业科学]