Potential short-term effects of yak and Tibetan sheep dung on greenhouse gas emissions in two alpine grassland soils under laboratory conditions

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• 作者：Yanjiang Cai (1)
  Xiaodan Wang (1)
  Weixin Ding (2)
  Linlin Tian (1)
  Hui Zhao (1)
  Xuyang Lu (1)
  
• 关键词：N2O ; CH4 ; Dung patch ; Alpine grassland ; Qinghai ; Tibetan Plateau
• 刊名：Biology and Fertility of Soils
• 出版年：2013
• 出版时间：November 2013
• 年：2013
• 卷：49
• 期：8
• 页码：1215-1226
• 全文大小：
• 作者单位：Yanjiang Cai (1)
  Xiaodan Wang (1)
  Weixin Ding (2)
  Linlin Tian (1)
  Hui Zhao (1)
  Xuyang Lu (1)
  
  1. Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, 610041, China
  2. State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
  
• ISSN：1432-0789

文摘

Yak and Tibetan sheep graze extensively on natural grasslands in the Qinghai-Tibetan Plateau, and large amounts of excrement are directly deposited onto alpine grasslands. However, information on greenhouse gas (GHG) emissions from this excrement is limited. This study evaluated the short-term effects of yak and Tibetan sheep dung on nitrous oxide (N2O), methane (CH4), and carbon dioxide (CO2) emissions from alpine steppe soil at a water holding capacity (WHC) of 40 or 60% and from alpine meadow soil at a WHC of 60 or 80% under laboratory conditions. Cumulative N2O emissions over a 15-day incubation period at low soil moisture conditions ranged from 111 to 232 N2Okg soil1 in the yak dung treatments, significantly (P<0.01) higher than that of sheep dung treatments (28.7 to 33.7 N2Okg soil1) and untreated soils (1.04.94 N2Okg soil1). At high soil moisture conditions, N2O emissions were higher from sheep dung than yak dung and non-treated soils. No significant difference was found between the yak dung and non-treated alpine meadow soil at 80% WHC. Low N2O emission in the yak dung treatment from relatively wet soil was probably due to complete denitrification to N2. Yak dung markedly (P<0.001) increased CH4 and CO2 emissions, likely being the main source of these two gases. The addition of sheep dung markedly (P<0.001) elevated CO2 emissions. Dung application significantly (P<0.01) increased global warming potential, particularly for alpine steppe soil. In conclusion, our findings suggest that yak and Tibetan sheep dung deposited on alpine grassland soils may increase GHG emissions.