title: Responses of greenhouse gas fluxes to experimental warming in wheat season under conventional tillage and no-tillage fields.
abstract: Understanding the effects of warming on greenhouse gas (GHG, such as N2O, CH4and CO2) feedbacks to climate change represents the major environmental issue. However, little information is available on how warming effects on GHG fluxes in farmland of North China Plain (NCP). An infrared warming simulation experiment was used to assess the responses of N2O, CH4and CO2to warming in wheat season of 2012-2014 from conventional tillage (CT) and no-tillage (NT) systems. The results showed that warming increased cumulative N2O emission by 7.7% in CT but decreased it by 9.7% in NT fields (p<0.05). Cumulative CH4uptake and CO2emission were increased by 28.7%-51.7% and 6.3%-15.9% in both two tillage systems, respectively (p<0.05). The stepwise regressions relationship between GHG fluxes and soil temperature and soil moisture indicated that the supply soil moisture due to irrigation and precipitation would enhance the positive warming effects on GHG fluxes in two wheat seasons. However, in 2013, the long-term drought stress due to infrared warming and less precipitation decreased N2O and CO2emission in warmed treatments. In contrast, warming during this time increased CH4emission from deep soil depth. Across two years wheat seasons, warming significantly decreased by 30.3% and 63.9% sustained-flux global warming potential (SGWP) of N2O and CH4expressed as CO2equivalent in CT and NT fields, respectively. However, increase in soil CO2emission indicated that future warming projection might provide positive feedback between soil C release and global warming in NCP.
authors.affiliation: Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: tuc.13b@igsnrr.ac.cn.
authors.forename: Chun
authors.initials: C
authors.lastname: Tu
authors.affiliation: Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100190, China. Electronic address: lifadong@igsnrr.ac.cn.
authors.forename: Fadong
authors.initials: F
authors.lastname: Li
mesh_terms: D000383:Agriculture / Q000379:methods*; D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000517:prevention & control* / Q000706:statistics & numerical data; D002245:Carbon Dioxide; D002681:China; D057231:Climate Change; D018556:Crops, Agricultural; D017752:Greenhouse Effect; D008697:Methane / Q000032:analysis; D009609:Nitrous Oxide / Q000032:analysis; D012621:Seasons; D013696:Temperature; D014908:Triticum
chemical_list: D000393:Air Pollutants; D002245:Carbon Dioxide; D009609:Nitrous Oxide; D008697:Methane
keywords: Climate warming; Conventional tillage; Greenhouse gas fluxes (N(2)O, CH(4), CO(2)); No-tillage; Soil moisture; Soil temperature