title: Prediction of future methane emission from irrigated rice paddies in central Thailand under different water management practices.
abstract: There is concern about positive feedbacks between climate change and methane (CH4) emission from rice paddies. However, appropriate water management may mitigate the problem. We tested this hypothesis at six field sites in central Thailand, where the irrigated area is rapidly increasing. We used DNDC-Rice, a process-based biogeochemistry model adjusted based on rice growth data at each site to simulate CH4 emission from a rice-rice double cropping system from 2001 to 2060. Future climate change scenarios consisting of four representative concentration pathways (RCPs) and seven global climate models were generated by statistical downscaling. We then simulated CH4 emission in three water management practices: continuous flooding (CF), single aeration (SA), and multiple aeration (MA). The adjusted model reproduced the observed rice yield and CH4 emission well at each site. The simulated CH4 emissions in CF from 2051 to 2060 were 5.3 to 7.8%, 9.6 to 16.0%, 7.3 to 18.0%, and 13.6 to 19.0% higher than those from 2001 to 2010 in RCPs 2.6, 4.5, 6.0, and 8.5, respectively, at the six sites. Regionally, SA and MA mitigated CH4 emission by 21.9 to 22.9% and 53.5 to 55.2%, respectively, relative to CF among the four RCPs. These mitigation potentials by SA and MA were comparable to those from 2001 to 2010. Our results indicate that climate change in the next several decades will not attenuate the quantitative effect of water management practices on mitigating CH4 emission from irrigated rice paddies in central Thailand.
authors.affiliation: Institute for Agro-Environmental Sciences, National Agriculture and Food Research Organization, 3-1-3 Kannondai, Tsukuba, Ibaraki 306-8604, Japan. Electronic address: minakazu@affrc.go.jp.
authors.forename: Kazunori
authors.initials: K
authors.lastname: Minamikawa
authors.affiliation: Institute for Agro-Environmental Sciences, National Agriculture and Food Research Organization, 3-1-3 Kannondai, Tsukuba, Ibaraki 306-8604, Japan.
authors.forename: Tamon
authors.initials: T
authors.lastname: Fumoto
authors.affiliation: Institute for Agro-Environmental Sciences, National Agriculture and Food Research Organization, 3-1-3 Kannondai, Tsukuba, Ibaraki 306-8604, Japan.
authors.forename: Toshichika
authors.initials: T
authors.lastname: Iizumi
authors.affiliation: The Joint Graduate School of Energy and Environment, Centre of Excellence on Energy Technology and Environment, King Mongkut's University of Technology Thonburi, 126 Prachauthit Rd, Bangmod, Tungkru, Bangkok 10140, Thailand.
authors.forename: Nittaya
authors.initials: N
authors.lastname: Cha-Un
authors.affiliation: The Joint Graduate School of Energy and Environment, Centre of Excellence on Energy Technology and Environment, King Mongkut's University of Technology Thonburi, 126 Prachauthit Rd, Bangmod, Tungkru, Bangkok 10140, Thailand.
authors.forename: Uday
authors.initials: U
authors.lastname: Pimple
authors.affiliation: Institute for Agro-Environmental Sciences, National Agriculture and Food Research Organization, 3-1-3 Kannondai, Tsukuba, Ibaraki 306-8604, Japan.
authors.forename: Motoki
authors.initials: M
authors.lastname: Nishimori
authors.affiliation: Institute for Agro-Environmental Sciences, National Agriculture and Food Research Organization, 3-1-3 Kannondai, Tsukuba, Ibaraki 306-8604, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Ishigooka
authors.affiliation: Institute for Agro-Environmental Sciences, National Agriculture and Food Research Organization, 3-1-3 Kannondai, Tsukuba, Ibaraki 306-8604, Japan.
authors.forename: Tsuneo
authors.initials: T
authors.lastname: Kuwagata
keywords: DNDC-Rice; Global warming; Intermittent irrigation; Midseason drainage; Regional climate downscaling