中国农业科学 ›› 2013, Vol. 46 ›› Issue (22): 4726-4732.doi: 10.3864/j.issn.0578-1752.2013.22.010

• 土壤肥料·节水灌溉·农业生态环境 • 上一篇    下一篇

硝化和反硝化过程对林地和草地土壤N2O排放的贡献

 李平1, 郎漫2   

  1. 1.南京信息工程大学/江苏省农业气象重点实验室,南京 210044
    2.南京信息工程大学应用气象学院,南京 210044
  • 收稿日期:2013-04-23 出版日期:2013-11-15 发布日期:2013-07-23
  • 通讯作者: 通信作者郎漫,Tel:025-58699784;E-mail:mlangnuist@163.com
  • 作者简介:李平,Tel:025-58699784;E-mail:pli@nuist.edu.cn
  • 基金资助:

    国家自然科学基金项目(41301345,41101284)、江苏省高校自然科学研究计划项目(12KJB210004)、江苏省农业气象重点实验室开放基金项目(KYQ1209)、江苏高校优势学科建设工程(PAPD)

Contribution of Nitrification and Denitrification to the Nitrous Oxide Emission from Forest and Grassland Soils

 LI  Ping-1, LANG  Man-2   

  1. 1.Nanjing University of Information Science & Technology/Jiangsu Key Laboratory of Agricultural Meteorology, Nanjing 210044;
    2.College of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044
  • Received:2013-04-23 Online:2013-11-15 Published:2013-07-23

摘要: 【目的】明确好气条件下硝化和反硝化过程对林地和草地土壤N2O排放的贡献,比较温度变化对两个过程排放贡献的影响。【方法】通过室内好气培养试验(60%WHC),采用15N同位素标记技术测定林地和草地土壤在10℃和15℃下铵态氮、硝态氮和N2O的15N丰度,计算硝化和反硝化过程对N2O排放的贡献。【结果】好气培养条件下,林地和草地土壤中的硝化作用和反硝化作用同时发生,硝化作用对N2O排放的贡献为53.1%―72.0%,是N2O排放的主要过程。培养期间林地土壤中反硝化过程对N2O排放的平均贡献为44.9%,显著大于草地土壤(28.9%),而硝化过程对N2O排放的平均贡献为55.1%,显著小于草地土壤(71.1%)。温度增加显著促进了土壤中N2O的排放,但是对硝化和反硝化过程的N2O排放贡献没有影响。【结论】好气条件下硝化作用是土壤中N2O排放的主要过程,但反硝化作用仍占有很大比例。

关键词: 硝化 , 反硝化 , N2O , 15N , 林地 , 草地

Abstract: 【Objective】It is of great significance to explore the contribution of nitrification and denitrification to the N2O emission from forest and grassland soils under aerobic condition, and to compare the response of the contribution to temperature change.【Method】An laboratory aerobic (60% water holding capacity) incubation experiment was conducted at 10℃ and 15℃ to measure the atom 15N excess of ammonium, nitrate, and nitrous oxide using 15N isotope tracers, the contribution of nitrification and denitrification to the N2O emission was calculated. 【Result】 Under aerobic condition, both processes occurred simultaneously and were involved in N2O production, 53.1%–72.0% of N-N2O came from nitrification, which is the main source of N2O from soils. The average contribution of denitrification to N2O emission was 44.9% for forest soil, which is significantly higher than grassland soil (28.9%), while nitrification of forest soil contributed 55.1% to N2O emission, which is significantly lower than grassland soil (71.1%). Increasing temperature from 10℃ to 15℃ increased N2O emission significantly for both two soils, but had no effects on the relative contribution of nitrification and denitrification to N2O emissions.【Conclusion】 Microbial transformation of nitrification is the main source of N2O from soils under aerobic condition, however, the proportion of N2O emitted from denitrification should not be neglected.

Key words: nitrification , denitrification , N2O , 15N , forest , grassland