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草业学报 ›› 2018, Vol. 27 ›› Issue (12): 22-33.DOI: 10.11686/cyxb2018062

• 研究论文 • 上一篇    下一篇

不同管理模式对干旱区草地土壤有机碳氮库的影响及其影响因素探究

蒋腊梅1, 2, 杨晓东1, 2, 3, 杨建军1, 2, 3, 何学敏2, 3, 吕光辉2, 3, *   

  1. 1.新疆大学资源与环境科学学院,新疆 乌鲁木齐 830046;
    2.新疆大学绿洲生态教育部重点实验室,新疆 乌鲁木齐 830046;
    3.新疆大学干旱生态环境研究所,新疆 乌鲁木齐 830046
  • 收稿日期:2018-01-25 修回日期:2018-06-06 出版日期:2018-12-20 发布日期:2018-12-20
  • 通讯作者: E-mail:ler@xju.edu.cn
  • 作者简介:蒋腊梅(1991-),女,新疆阿图什人,在读硕士。E-mail:1977812633@qq.com
  • 基金资助:
    国家科技支撑计划(2014BAC15B04)资助。

Effects of different management strategies on soil organic carbon and nitrogen pools in arid areas and their influencing factors

JIANG La-mei1, 2, YANG Xiao-dong1, 2, 3, YANG Jian-jun1, 2, 3, HE Xue-min2, 3, LÜ Guang-hui2, 3, *   

  1. 1.The College of Resource Environment Science of Xinjiang University, Urumqi 830046, China;
    2.Ministry of Education Key Laboratory of Oasis Ecology of Xinjiang University, Urumqi 830046, China;
    3.Research Institute of Arid Ecological Environment of Xinjiang University, Urumqi 830046, China
  • Received:2018-01-25 Revised:2018-06-06 Online:2018-12-20 Published:2018-12-20
  • Contact: E-mail:ler@xju.edu.cn

摘要: 土壤有机碳和全氮含量及其动态平衡过程是反映土壤质量和草地健康状况的重要指标,直接影响到草地土壤肥力和草地生产力。本研究对新疆阿勒泰地区禁牧草场、弃耕草地、天然草地3种管理模式下的土壤有机碳、全氮、土壤水分、团粒结构、pH、土壤容重等的分布特征,以及它们的关系进行分析后发现,3种管理模式下,土壤有机碳含量在010 cm、1030 cm和3050 cm土层间无显著差别(P>0.05),相反,土壤碳氮比、土壤全氮含量、土壤有机碳储量和全氮储量随土层深度增加显著增加(P<0.05);3种管理模式间,在010 cm、1030 cm和3050 cm土层,天然草地和禁牧草地的全氮和有机碳含量均高于弃耕草地,但对土壤碳氮比在3种草地管理模式间的差异不尽相同;不同管理方式下,在010 cm、1030 cm和3050 cm土层,禁牧草地的土壤电导率和pH均显著高于天然草地(P<0.05);在010 cm和3050 cm土层,禁牧草地的土壤含水量显著高于弃耕草地(P<0.05),禁牧草地与弃耕草地中间团聚体含量差异显著(P<0.05);含水量、大团聚体、中间团聚体、微团聚体、pH、电导率可以组成原因组,土壤全氮储量和土壤有机碳储量可以组成结果组,原因组对结果组的解释度高达75.70%;原因组中,土壤水分贡献率最高,土壤含水量对土壤水分-团粒结构起到主要决定作用。综合可知,土壤碳氮含量和储量在管理模式不同的草地间不同,土壤水分和土壤团粒结构是引起草地土壤碳氮库变化的主要原因。在土壤水分和团粒结构组成的原因组中,水分起主要的决定作用。

关键词: 土壤有机碳, 土壤全氮, 土壤含水量, 土壤团聚体, 管理模式, 草地, 干旱区

Abstract: The organic carbon content and total nitrogen content in soil and their dynamic balance are important indicators of the quality of soil and grassland. The aim of this study was to determine the effects of different management strategies on the quality of soil and grassland in the Xinjiang Aletai area. We analyzed soil in grasslands under three different management strategies (natural pasture, grazed pasture, and abandoned grassland), and determined soil organic carbon content, total nitrogen content, soil moisture, aggregate structure, pH, soil bulk density, and the relationships among these parameters. The soil carbon∶nitrogen ratio, total nitrogen content, organic carbon content, and total nitrogen reserves increased significantly with increasing soil depth (P<0.05). The soil total nitrogen contents and organic carbon contents in the 0-10 cm, 10-30 cm, and 30-50 cm soil layers were higher in natural grassland and grazed grassland than in abandoned grassland, but the soil carbon∶nitrogen ratio did not differ among the three types of grasslands. In the 0-10 cm, 10-30 cm, and 30-50 cm soil layers, soil conductivity and pH were significantly higher in grazed grassland than in natural grassland (P<0.05). In the 0-10 cm and 30-50 cm soil layers, the soil moisture content was significantly higher in grazed grassland than in abandoned grassland (P<0.05). The intermediate aggregate content differed significantly between abandoned grassland and the other two types of grasslands (P<0.05). Data for soil carbon content, nitrogen storage, and physical and chemical factors were used in correlation and canonical correlation analyses. In these analyses, the soil water content, aggregates, intermediate aggregates, micro aggregates, pH, and conductivity were explanatory variables, and soil nitrogen reserves and soil organic carbon reserves were the response variables. The explanatory factors explained up to 75.70% of the variation in soil nitrogen and soil organic carbon reserves, with soil moisture and aggregate structure showing strongest correlations with the response variables. We concluded that the soil carbon and nitrogen contents and reserves differed among the different management strategies, and that soil moisture content and soil aggregate structure were the main variables affecting soil carbon and nitrogen pools. Water content was strongly related to soil moisture and aggregate structure.

Key words: soil organic carbon, soil nitrogen, soil water content, soil aggregates, management modes, grassland, arid area