title: Methane, carbon dioxide and nitrous oxide fluxes in soil profile under a winter wheat-summer maize rotation in the North China Plain.
abstract: The production and consumption of the greenhouse gases (GHGs) methane (CH4), carbon dioxide (CO2) and nitrous oxide (N2O) in soil profile are poorly understood. This work sought to quantify the GHG production and consumption at seven depths (0-30, 30-60, 60-90, 90-150, 150-200, 200-250 and 250-300 cm) in a long-term field experiment with a winter wheat-summer maize rotation system, and four N application rates (0; 200; 400 and 600 kg N ha(-1) year(-1)) in the North China Plain. The gas samples were taken twice a week and analyzed by gas chromatography. GHG production and consumption in soil layers were inferred using Fick's law. Results showed nitrogen application significantly increased N2O fluxes in soil down to 90 cm but did not affect CH4 and CO2 fluxes. Soil moisture played an important role in soil profile GHG fluxes; both CH4 consumption and CO2 fluxes in and from soil tended to decrease with increasing soil water filled pore space (WFPS). The top 0-60 cm of soil was a sink of atmospheric CH4, and a source of both CO2 and N2O, more than 90% of the annual cumulative GHG fluxes originated at depths shallower than 90 cm; the subsoil (>90 cm) was not a major source or sink of GHG, rather it acted as a 'reservoir'. This study provides quantitative evidence for the production and consumption of CH4, CO2 and N2O in the soil profile.
authors.affiliation: Key Laboratory of Agricultural Water Resources, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, Hebei, China.
authors.forename: Yuying
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Key Laboratory of Agricultural Water Resources, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, Hebei, China.
authors.forename: Chunsheng
authors.initials: C
authors.lastname: Hu
authors.affiliation: Key Laboratory of Agricultural Water Resources, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, Hebei, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Ming
authors.affiliation: Department of Soil Quality, Wageningen University, Alterra, Wageningen, The Netherlands.
authors.forename: Oene
authors.initials: O
authors.lastname: Oenema
authors.affiliation: Key Lab of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Yunnan, China.
authors.forename: Douglas A
authors.initials: DA
authors.lastname: Schaefer
authors.affiliation: Key Laboratory of Agricultural Water Resources, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, Hebei, China.
authors.forename: Wenxu
authors.initials: W
authors.lastname: Dong
authors.affiliation: Key Laboratory of Agricultural Water Resources, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, Hebei, China.
authors.forename: Yuming
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Agricultural Water Resources, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, Hebei, China.
authors.forename: Xiaoxin
authors.initials: X
authors.lastname: Li
mesh_terms: D002245:Carbon Dioxide / Q000032:analysis*; D002681:China; D008697:Methane / Q000032:analysis*; D009609:Nitrous Oxide / Q000032:analysis*; D012621:Seasons; D012987:Soil / Q000737:chemistry*; D014908:Triticum; D003313:Zea mays
chemical_list: D012987:Soil; D002245:Carbon Dioxide; D009609:Nitrous Oxide; D008697:Methane