title: Mitigation of soil N2O emission by inoculation with a mixed culture of indigenous Bradyrhizobium diazoefficiens.
abstract: Agricultural soil is the largest source of nitrous oxide (N2O), a greenhouse gas. Soybean is an important leguminous crop worldwide. Soybean hosts symbiotic nitrogen-fixing soil bacteria (rhizobia) in root nodules. In soybean ecosystems, N2O emissions often increase during decomposition of the root nodules. Our previous study showed that N2O reductase can be used to mitigate N2O emission from soybean fields during nodule decomposition by inoculation with nosZ++ strains [mutants with increased N2O reductase (N2OR) activity] of Bradyrhizobium diazoefficiens. Here, we show that N2O emission can be reduced at the field scale by inoculation with a mixed culture of indigenous nosZ+ strains of B. diazoefficiens USDA110 group isolated from Japanese agricultural fields. Our results also suggested that nodule nitrogen is the main source of N2O production during nodule decomposition. Isolating nosZ+ strains from local soybean fields would be more applicable and feasible for many soybean-producing countries than generating mutants.
authors.affiliation: Institute for Agro-Environmental Sciences, National Agriculture and Food Research Organization (NARO), 3-1-3, Kannondai, Tsukuba, Ibaraki 305-8604, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Akiyama
authors.affiliation: Institute for Agro-Environmental Sciences, National Agriculture and Food Research Organization (NARO), 3-1-3, Kannondai, Tsukuba, Ibaraki 305-8604, Japan.
authors.forename: Yuko Takada
authors.initials: YT
authors.lastname: Hoshino
authors.affiliation: Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Itakura
authors.affiliation: Institute for Agro-Environmental Sciences, National Agriculture and Food Research Organization (NARO), 3-1-3, Kannondai, Tsukuba, Ibaraki 305-8604, Japan.
authors.forename: Yumi
authors.initials: Y
authors.lastname: Shimomura
authors.affiliation: Institute for Agro-Environmental Sciences, National Agriculture and Food Research Organization (NARO), 3-1-3, Kannondai, Tsukuba, Ibaraki 305-8604, Japan.
authors.forename: Yong
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Institute for Agro-Environmental Sciences, National Agriculture and Food Research Organization (NARO), 3-1-3, Kannondai, Tsukuba, Ibaraki 305-8604, Japan.
authors.forename: Akinori
authors.initials: A
authors.lastname: Yamamoto
authors.affiliation: Institute for Agro-Environmental Sciences, National Agriculture and Food Research Organization (NARO), 3-1-3, Kannondai, Tsukuba, Ibaraki 305-8604, Japan.
authors.forename: Kanako
authors.initials: K
authors.lastname: Tago
authors.affiliation: Institute for Agro-Environmental Sciences, National Agriculture and Food Research Organization (NARO), 3-1-3, Kannondai, Tsukuba, Ibaraki 305-8604, Japan.|Advanced Analysis Center, NARO, 3-1-3, Kannondai, Tsukuba, Ibaraki 305-8604, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Nakajima
authors.affiliation: Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan.
authors.forename: Kiwamu
authors.initials: K
authors.lastname: Minamisawa
authors.affiliation: Institute for Agro-Environmental Sciences, National Agriculture and Food Research Organization (NARO), 3-1-3, Kannondai, Tsukuba, Ibaraki 305-8604, Japan.
authors.forename: Masahito
authors.initials: M
authors.lastname: Hayatsu
mesh_terms: D001673:Biodegradation, Environmental; D020369:Bradyrhizobium / Q000378:metabolism*; D017753:Ecosystem; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D009154:Mutation; D009584:Nitrogen / Q000032:analysis; D009586:Nitrogen Fixation; D009609:Nitrous Oxide / Q000032:analysis*; D018517:Plant Roots / Q000382:microbiology; D018520:Plant Shoots / Q000382:microbiology; D012987:Soil / Q000737:chemistry*; D012988:Soil Microbiology; D013025:Glycine max / Q000382:microbiology
chemical_list: D012987:Soil; D009609:Nitrous Oxide; D009584:Nitrogen