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草业学报 ›› 2022, Vol. 31 ›› Issue (2): 159-170.DOI: 10.11686/cyxb2021175

• 研究论文 • 上一篇    

苜蓿与3种多年生禾草混播效应研究

张辉辉(), 师尚礼(), 武蓓, 李自立, 李小龙   

  1. 甘肃农业大学草业学院,草业生态系统教育部重点实验室,中-美草地畜牧业可持续发展研究中心,甘肃 兰州 730070
  • 收稿日期:2021-05-06 修回日期:2021-06-30 出版日期:2022-02-20 发布日期:2021-12-22
  • 通讯作者: 师尚礼
  • 作者简介:Corresponding author. E-mail: Shishl@gsau.edu.cn
    张辉辉(1995-),男,甘肃定西人,在读硕士。E-mail: 2271484220@qq.com
  • 基金资助:
    财政部和农业农村部,国家现代农业产业技术体系(CARS-34)

A study of yield interactions in mixed sowings of alfalfa and three perennial grasses

Hui-hui ZHANG(), Shang-li SHI(), Bei WU, Zi-li LI, Xiao-long LI   

  1. Pratacultural College,Gansu Agricultural University,Key Laboratory of Grassland Ecosystem of Ministry of Education,Sino-U. S. Centers for Grazing Land Ecosystem Sustainability,Lanzhou 730070,China
  • Received:2021-05-06 Revised:2021-06-30 Online:2022-02-20 Published:2021-12-22
  • Contact: Shang-li SHI

摘要:

以紫花苜蓿分别与草地早熟禾、无芒雀麦和苇状羊茅按混播比例为7∶3、5∶5和3∶7建立的人工草地群落为研究对象,以4个草种单播处理为对照,通过对生物量、植物形态特征以及种间关系的测定分析,探讨种间关系对混播草种和比例的响应以及植物生长特征和生物量对种间关系的响应,为建植高产、优质的混播草地提供理论基础。研究结果表明3种混播组合中紫花苜蓿相对产量(RY)值均大于1.0且大于禾草,紫花苜蓿较禾草均具有竞争优势,紫花苜蓿+草地早熟禾和紫花苜蓿+无芒雀麦混播组合中,紫花苜蓿对禾草的生长具有压迫作用,紫花苜蓿+苇状羊茅组合表现为两种牧草协同生长。随紫花苜蓿比例的下降和禾草比例的提高,紫花苜蓿RY值表现为豆禾比例3∶7>5∶5>7∶3,禾草RY值表现为豆禾比例3∶7>7∶3>5∶5,混播系统通过降低紫花苜蓿株高、增加茎粗和叶面积,禾草通过提高株高,降低茎粗以及先增大再减小叶面积来响应种间关系的变化,使得各混播比例下相对产量总和(RYT)值均大于1.0,进而使两种牧草达到协同生长,最终达到增产的目的。3种混播组合中,紫花苜蓿与苇状羊茅混播增产效果好于其他混播组合,并且以3∶7混播增产率最高,紫花苜蓿与草地早熟禾、紫花苜蓿与无芒雀麦以7∶3混播增产效率最高。

关键词: 紫花苜蓿, 多年生禾草, 混播, 种间关系, 形态特征, 产量

Abstract:

This study investigated the yield and competitive interactions in three mixed-sown combinations of alfalfa (Medicago sativa) and a perennial grass (M. sativa+Poa pratensisM. sativa+Bromus inermis and M. sativa+Festuca arundinacea). The mixtures were established at legume∶grass ratios of 7∶3, 5∶5, and 3∶7, and monocultures of alfalfa and the three grasses were also included as a contrast. Data on biomass and key morphological traits of each species in the various monocultures and mixed sowings were collated and analyzed to investigate the competitive interactions between alfalfa and the three grass species, so as to provide a theoretical basis for the development of management guidelines for high yield and high quality of mixed sown pasture. Results indicated that the relative yield (RY) values of alfalfa in the three mixed sowing combinations were higher than 1.0 and that alfalfa had a competitive advantage over the grasses. The growth of the grass in the combinations of M. sativa+P. pratensis and M. sativa+B. inermis was suppressed by alfalfa, while grass in M. sativa+F. arundinacea combination grew synergistically with alfalfa. For the three legume∶grass ratios tested in the mixed-sown plots, the RY for the alfalfa component ranked 3∶7>5∶5>7∶3 and RY for the grass component ranked 3∶7>7∶3>5∶5. For the alfalfa component, responses to the mixed sowing systems included reduced plant height and increased stem diameter and leaf area. For the grass component, plant height increased and stem diameter reduced were also observed but leaf area was increased in mild competition and decreased in more intense competition. These responses resulted in a high (>1.0) total relative yield (RYT) value under different mixed sowing ratios. The species in the mixed sown plots adapted to the variations in the interspecific relationship by adjusting their morphological characteristics, and these adjustments provided the mechanism for the achievement of synergistic growth and yield increase. Among the three mixed sown combinations, M. sativa+F. arundinacea exhibited a greater biomass-increasing effect than the others, especially with the legume:grass ratio of 3∶7. In contrast, in the mixed sowings of M. sativa+P. pratensis and M. sativa+B. inermis, the legume∶grass ratio of 7∶3 had the highest biomass-increasing effect.

Key words: alfalfa, perennial grasses, mixed sowing, interspecific competition, morphological character, forage yield