西北内陆干旱区水分调控对豆禾混播草地群落稳定性的影响及评价

Effect and evaluation of water regulation on the sta⁃ bility of bean-grain mixed seeding grassland communities in the inland dry zone of Northwest China

摘要:

在西北内陆干旱区干旱少雨，探寻高产节水的草地群落以实现生态环境的稳定。通过 2 a (2019 和 2020 年)田间试验，对比分析了 4 种水分调控梯度(充分灌溉 W0，75%~85% 的田间持水量 (FC)；轻度亏水 W1，65%~75% FC；中度亏水 W2，55%~65% FC；重度亏水 W3，45%~55% FC)和 3 种豆禾混播组合(紫花苜蓿+无芒雀麦，A1；紫花苜蓿+无芒雀麦+长穗偃麦草，A2；紫花苜蓿+无芒雀麦+长穗偃麦草+草地早熟禾，A3)对群落稳定性的影响。结果表明：水分调控与混播组合对混播草地组分稳定性无显著影响，但显著影响混播草地功能稳定性(产量和粗蛋白含量)和种间相容性， 水分调控与混播组合的交互效应对草地的组分稳定性、功能稳定性和种间相容性均无显著影响。综合评价得出，轻度水分亏缺条件下紫花苜蓿+无芒雀麦+长穗偃麦草混播处理的加权关联度最高，综合排名最优，是西北内陆干旱区适宜的豆禾混播组合与灌水管理模式，该研究可为当地人工草地高效节水可持续生产提供理论基础及技术支持。

Abstract:

Based on the characteristics of drought and less rainfall in the inland arid region of Northwest China， grassland yield is low and unstable，so it is of great significance to explore more high-yield and water-saving grassland communities to realize the stability of ecological environment. Through two years of field experiments(2019 and 2020)，four water regulation gradients(fully irrigated W0，75%~85% FC(field water capacity)；Mild water deficit W1，65%~75% FC；Moderate water deficit W2，55%~65% FC；Severe water deficit W3，45%~55% FC)were compared and analyzed for the effect on the community stability. Three bean-grain mixed seeding combinations(Al- falfa/Brumos inermis(A1)，Alfalfa/B. inermis/Elytrigia elongata(A2)and Alfalfa/B. inermis/E. elongate/Poa pra- tensis.(A3)were studied in the field experiments. The results showed that the combination of water regulation and mixed seeding had no significant effect on the component stability of mixed seeded grass，but significantly affected the functional stability(yield and crude protein content)，and interspecific compatibility of mixed seeded grass. The inter- action effect of water regulation and mixed sowing combination didn’t significantly affect the component stability， functional stability or interspecific compatibility of the grasses. The comprehensive evaluation showed that under mild water deficit conditions，A2 mixed sowing treatment had the highest weighted correlation and the best comprehensive ranking，which is a suitable bean-grain mixed sowing combination and irrigation management mode in the northwest inland arid zone.