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草业学报 ›› 2024, Vol. 33 ›› Issue (5): 92-105.DOI: 10.11686/cyxb2023219

• 研究论文 • 上一篇    下一篇

紫花苜蓿/甜高粱间作对根际土壤特性及微生物群落特征的影响

何升然(), 刘晓静(), 赵雅姣, 汪雪, 王静   

  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,甘肃省草业工程实验室,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:2023-06-28 修回日期:2023-07-28 出版日期:2024-05-20 发布日期:2024-02-03
  • 通讯作者: 刘晓静
  • 作者简介:E-mail: liuxj@gsau.edu.cn
    何升然(1998-),男,安徽霍山人,在读硕士。E-mail: 949561991@qq.com
  • 基金资助:
    国家自然科学基金项目(32171674);兰州市人才创新创业项目(2023-RC-40);甘肃省重点研发计划项目(20YF8NA130)

Effects of alfalfa/sweet sorghum intercropping on rhizosphere soil characteristics and microbial community characteristics

Sheng-ran HE(), Xiao-jing LIU(), Ya-jiao ZHAO, Xue WANG, Jing WANG   

  1. College of Pratacultural Science,Gansu Agricultural University,Key Laboratory of Pratacultural Ecosystem,Ministry of Education,Pratacultural Engineering Laboratory of Gansu Province,Sino-U. S. Centers for Grazingland Ecosystem Sustainability,Lanzhou 730070,China
  • Received:2023-06-28 Revised:2023-07-28 Online:2024-05-20 Published:2024-02-03
  • Contact: Xiao-jing LIU

摘要:

为探究紫花苜蓿/甜高粱间作体系对根际土壤微生态环境的影响,改善土壤结构、维持良好的土壤微生态环境和实现土地生态保护提供理论依据,本研究以紫花苜蓿和甜高粱为对象,对其连续3年单作和间作种植下的结瘤固氮特性、根际土壤养分、土壤酶活性以及种植第3年的土壤微生物群落特征及其之间的相互关系进行研究。结果表明:紫花苜蓿/甜高粱间作系统内的变形菌门(Proteobacteria)、拟杆菌门(Bacteroidetes)和芽孢杆菌属(Bacillus)为主要优势菌群,且与单作相比,间作有效提高了根际土壤中的拟杆菌门、变形菌门、放线菌门(Actinobacteria)和Gp6相对丰度,显著提高了甜高粱根际土壤有机质含量、有效磷含量、脲酶活性和蔗糖酶活性(P<0.05),显著提高了紫花苜蓿固氮酶活性和单株固氮潜力(P<0.05),同时显著降低了间作中2种牧草的根际土壤pH值(P<0.05)。间作紫花苜蓿根际土壤碱性磷酸酶和蔗糖酶的活性随着年份的增加逐年提升,同时3种种植模式下根际土壤pH值均随年份的增加显著降低(P<0.05)。相关性分析发现,4个根际土壤酶与碱解氮、速效钾和有机质呈极显著正相关(P<0.01);变形菌门和拟杆菌门与pH值呈极显著负相关,与碱解氮呈极显著正相关,而酸杆菌门(Acidobacteria)和疣微菌门(Verrucomicrobia)与pH值呈极显著正相关,与碱解氮呈极显著负相关(P<0.01)。因此,紫花苜蓿/甜高粱间作可以改善根际土壤结构,提高土壤微生物活性。

关键词: 紫花苜蓿/甜高粱间作, 根际土壤养分, 根际土壤酶, 细菌群落

Abstract:

In this study, we explored the influence of an alfalfa (Medicago sativa)/sweet sorghum (Sorghum dochna) intercropping system on the microecological environment of soil in the rhizosphere. The overall aims of our research were to provide a scientific and theoretical basis for improving soil structure, maintaining a good soil microecological environment, and protecting the ecological value of agricultural land. A 3-year field study was conducted with alfalfa and sweet sorghum grown as monocrops and in an intercropping system. We evaluated nodulation and nitrogen fixation, rhizosphere soil nutrient contents, soil enzyme activities, and the soil microbial community characteristics and their interrelationships over 3 consecutive years. The results showed that Proteobacteria, Bacteroidetes, and Bacillus were the dominant bacteria in the alfalfa/sweet sorghum intercropping system. Intercropping effectively increased the relative abundance of Bacteroidetes, Proteobacteria, Actinobacteria, and Gp6 in the rhizosphere soil, significantly increased soil organic matter and available phosphorus contents, and increased urease activity and invertase activity in the rhizosphere soil of sweet sorghum (P<0.05). Intercropping also significantly increased nitrogenase activity and the nitrogen-fixation capacity (P<0.05), and significantly reduced the rhizosphere soil pH of both alfalfa and sweet sorghum (P<0.05). The activities of alkaline phosphatase and invertase increased in the rhizosphere soil of intercropped alfalfa over the 3 years, and the pH of rhizosphere soil decreased significantly over the 3 years in both monocrops and in the intercropping system (P<0.05). The results of the correlation analysis indicated that four rhizosphere soil enzymes were positively correlated with available nitrogen, available potassium, and organic matter (P<0.01); Proteobacteria and Bacteroidetes were negatively correlated with pH and positively correlated with available nitrogen; and Acidobacteria and Verrucomicrobia were positively correlated with pH and negatively correlated with available nitrogen (P<0.01). Therefore, alfalfa/sweet sorghum intercropping was shown to improve the soil structure and increase the activity of soil microorganisms.

Key words: alfalfa/sweet sorghum intercropping, rhizosphere soil nutrients, rhizosphere soil enzymes, bacterial community