title: Effects of nitrogen and biochar amendment on soil methane concentration profiles and diffusion in a rice-wheat annual rotation system.
abstract: The CH4emissions from soil were influenced by the changeable CH4concentrations and diffusions in soil profiles, but that have been subjected to nitrogen (N) and biochar amendment over seasonal and annual time frames. Accordingly, a two-year field experiment was conducted in southeastern China to determine the amendment effects on CH4concentrations and diffusive effluxes as measured by a multilevel sampling probe in paddy soil during two cycles of rice-wheat rotations. The results showed that the top 7-cm soil layers were the primary CH4production sites during the rice-growing seasons. This layer acted as the source of CH4generation and diffusion, and the deeper soil layers and the wheat season soil acted as the sink. N fertilization significantly increased the CH4concentration and diffusive effluxes in the top 7-cm layers during the 2013 and 2014 rice seasons. Following biochar amendment, the soil CH4concentrations significantly decreased during the rice season in 2014, relative to the single N treatment. Moreover, 40 t ha-1biochar significantly decreased the diffusive effluxes during the rice seasons in both years. Therefore, our results showed that biochar amendment is a good strategy for reducing the soil profile CH4concentrations and diffusive effluxes induced by N in paddy fields.
authors.affiliation: Jiangsu Key Laboratory of Low Carbon Agriculture and GHGs Mitigation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Xu
authors.affiliation: Jiangsu Key Laboratory of Low Carbon Agriculture and GHGs Mitigation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Wu
authors.affiliation: Jiangsu Key Laboratory of Low Carbon Agriculture and GHGs Mitigation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Yubing
authors.initials: Y
authors.lastname: Dong
authors.affiliation: Jiangsu Key Laboratory of Low Carbon Agriculture and GHGs Mitigation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Ziqiang
authors.initials: Z
authors.lastname: Zhou
authors.affiliation: Jiangsu Key Laboratory of Low Carbon Agriculture and GHGs Mitigation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Zhengqin
authors.initials: Z
authors.lastname: Xiong
mesh_terms: D000383:Agriculture; D002606:Charcoal / Q000737:chemistry*; D002681:China; D004058:Diffusion; D008697:Methane / Q000032:analysis*; D009584:Nitrogen / Q000737:chemistry*; D012275:Oryza; D012987:Soil / Q000737:chemistry*; D014908:Triticum
chemical_list: D012987:Soil; C540010:biochar; D002606:Charcoal; D009584:Nitrogen; D008697:Methane