title: Microbial Abundances Predict Methane and Nitrous Oxide Fluxes from a Windrow Composting System.
abstract: Manure composting is a significant source of atmospheric methane (CH4) and nitrous oxide (N2O) that are two potent greenhouse gases. The CH4and N2O fluxes are mediated by methanogens and methanotrophs, nitrifying and denitrifying bacteria in composting manure, respectively, while these specific bacterial functional groups may interplay in CH4and N2O emissions during manure composting. To test the hypothesis that bacterial functional gene abundances regulate greenhouse gas fluxes in windrow composting systems, CH4and N2O fluxes were simultaneously measured using the chamber method, and molecular techniques were used to quantify the abundances of CH4-related functional genes (mcrAandpmoAgenes) and N2O-related functional genes (amoA,narG,nirK,nirS,norB, andnosZgenes). The results indicate that changes in interacting physicochemical parameters in the pile shaped the dynamics of bacterial functional gene abundances. The CH4and N2O fluxes were correlated with abundances of specific compositional genes in bacterial community. The stepwise regression statistics selected pile temperature,mcrAand NH4+together as the best predictors for CH4fluxes, and the model integratingnirK,nosZwithpmoAgene abundances can almost fully explain the dynamics of N2O fluxes over windrow composting. The simulated models were tested against measurements in paddy rice cropping systems, indicating that the models can also be applicable to predicting the response of CH4and N2O fluxes to elevated atmospheric CO2concentration and rising temperature. Microbial abundances could be included as indicators in the current carbon and nitrogen biogeochemical models.
authors.affiliation: Jiangsu Key Laboratory of Low Carbon Agriculture and GHGs Mitigation, College of Resources and Environmental Sciences, Nanjing Agricultural UniversityNanjing, China; Jiangsu Key Laboratory and Engineering Center for Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural UniversityNanjing, China.
authors.forename: Shuqing
authors.initials: S
authors.lastname: Li
authors.affiliation: Jiangsu Key Laboratory of Low Carbon Agriculture and GHGs Mitigation, College of Resources and Environmental Sciences, Nanjing Agricultural University Nanjing, China.
authors.forename: Lina
authors.initials: L
authors.lastname: Song
authors.affiliation: Jiangsu Key Laboratory of Low Carbon Agriculture and GHGs Mitigation, College of Resources and Environmental Sciences, Nanjing Agricultural University Nanjing, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Gao
authors.affiliation: Jiangsu Key Laboratory of Low Carbon Agriculture and GHGs Mitigation, College of Resources and Environmental Sciences, Nanjing Agricultural University Nanjing, China.
authors.forename: Yaguo
authors.initials: Y
authors.lastname: Jin
authors.affiliation: Jiangsu Key Laboratory of Low Carbon Agriculture and GHGs Mitigation, College of Resources and Environmental Sciences, Nanjing Agricultural UniversityNanjing, China; Jiangsu Key Laboratory and Engineering Center for Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural UniversityNanjing, China.
authors.forename: Shuwei
authors.initials: S
authors.lastname: Liu
authors.affiliation: Jiangsu Key Laboratory and Engineering Center for Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University Nanjing, China.
authors.forename: Qirong
authors.initials: Q
authors.lastname: Shen
authors.affiliation: Jiangsu Key Laboratory of Low Carbon Agriculture and GHGs Mitigation, College of Resources and Environmental Sciences, Nanjing Agricultural UniversityNanjing, China; Jiangsu Key Laboratory and Engineering Center for Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural UniversityNanjing, China.
authors.forename: Jianwen
authors.initials: J
authors.lastname: Zou
keywords: CH4; N2O; bacterial gene abundance; carbon and nitrogen biogeochemistry; greenhouse gas; statistical model