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草业学报 ›› 2017, Vol. 26 ›› Issue (8): 65-73.DOI: 10.11686/cyxb2016433

• 研究论文 • 上一篇    下一篇

不同管理措施对高寒草甸土壤微生物氮素生理群数量影响研究

张建贵1, 蒋永梅1, 姚拓1, *, 高亚敏1, 李海云1, 兰晓君1, 田永亮1, 李建宏1, 张英2   

  1. 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;
    2.青海大学农牧学院,青海 西宁 810016
  • 收稿日期:2016-11-15 出版日期:2017-08-20 发布日期:2017-08-20
  • 作者简介:张建贵(1991-),男,甘肃靖远人,在读硕士。E-mail:zhangjgyx@yeah.net
  • 基金资助:
    国家自然科学基金资助项目(31360584)和国家科技支撑技术(2009BAC53B06)资助

Effects of different management strategies on the number of soil nitrogen microorganism groups in an alpine meadow

ZHANG Jian-Gui1, JIANG Yong-Mei1, YAO Tuo1, *, GAO Ya-Min1, LI Hai-Yun1, LAN Xiao-Jun1, TIAN Yong-Liang1, LI Jian-Hong1, ZHANG Ying2   

  1. 1.College of Pratacultural Science, Gansu Agricultural University, Key Laboratory of Grassland Ecosystem, Ministery of Education, Pratacultural Engineering Laboratory of Gansu Province, Sino-U.S. Centers for Grazingland Ecosystem Sustainability, Lanzhou 730070, China;
    2.Agriculture and Animal Husbandry College of Qinghai University, Xining 810016, China
  • Received:2016-11-15 Online:2017-08-20 Published:2017-08-20

摘要: 从微观视野认识土壤氮素形成机理,为高寒草甸微生物生长和恢复提供科学依据。本研究采用平板表面涂抹法和稀释法对玛曲高寒草甸4种不同管理措施(不围栏、围栏、围栏+施肥、围栏+补播)土壤微生物氮素生理群数量进行了测定分析,结果表明,1)同一管理措施下,不同空间层次土壤微生物氮素生理群数量变化较大,具有明显的垂直分布规律,0~10 cm和10~20 cm土层的数量均显著高于20~30 cm土层(P<0.05),一般前者是后者的1.23~4.03倍和1.11~2.25倍;且不同土壤微生物氮素生理群之间数量差异显著,氨化细菌>反硝化细菌>硝化细菌>好气性固氮菌>嫌气性固氮菌。2)同一空间层次,不同管理措施土壤微生物氮素生理群间数量差异较大。土壤微生物氮素生理群数量以围栏+施肥和围栏+补播草地最高,围栏草地次之,不围栏草地最少。3)不同管理措施,土壤铵态氮和硝态氮含量随着土层深度增加逐渐减少,但围栏+施肥和围栏+补播处理均显著高于其他处理(P<0.05)。可见,围栏+施肥和围栏+补播措施对玛曲高寒草甸土壤微生物氮素生理群数量和不同形态氮素含量有提高效果。

Abstract: Understanding the micro-mechanisms of soil nitrogen formation can provide useful information about the growth and recovery of microorganisms in an alpine meadow. In this study, soil samples were collected from the alpine meadow in Maqu from sites under four types of management; unfenced, enclosed, enclosed with fertilization, and enclosed with sowing. The number of soil nitrogen microorganism groups was determined by the plate colony count and MPN (most probable number) methods. The number of nitrogen bacterial groups decreased with increasing soil depth at all sites. The number of nitrogen bacterial groups was significantly higher in the 0-10 cm and the 10-20 cm soil layers (P<0.05) than in the 20-30 cm soil layer (1.23-4.03 times and 1.11-2.25 times that in the 20-30 cm soil layer, respectively). There were also significant differences in abundance among the microorganism groups. The groups were ranked, from most abundant to least abundant, as follows: ammonifiers>denitrifying bacteria>nitrifiers>aerobic nitrogen-fixing bacteria (aerobic NFB)>anaerobic nitrogen-fixing bacteria (anaerobic NFB). In the same soil layer, there were significant differences in the abundance of bacterial groups among the different management strategies. The nitrogen bacterial groups were most abundant in the enclosed fertilized grassland and enclosed sown grassland, less abundant in enclosed grassland, and least abundant in the unfenced grassland. The amounts of ammonium nitrogen and nitrate nitrogen decreased with increasing soil depth in all treatments, and were significantly higher in enclosed fertilized grassland and enclosed sown grassland (P<0.05) than in enclosed grassland and unfenced grassland. These results show that, in the alpine meadow, the number and types of soil microorganisms and the contents of different forms of nitrogen can be increased by enclosure with sowing and enclosure with fertilization.