TY  - SER
AU  - Nannaphat Niyomsri
AU  - Cruz,Simon Guerrero
AU  - Ghimire,Anish
AU  - Ekbordin Winijkul,
AU  - Shanmugam,Mohana Sundaram
ED  - Royal Thai Government Fellowship,
TI  - Effect of metal micronutrients on methanotrophy and methanogenesis in rice cultivation: a mesocosm study
T2  - Thesis
PY  - 2025///
CY  - Pathum Thani, Thailand
PB  - Asian Institute of Technology
KW  - Greenhouse gases
KW  - Atmospheric methane
KW  - Environmental aspects
KW  - Crops and climate
N1  - A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Environmental Engineering and Management; Thesis (M. Sc.) - Asian Institute of Technology, 2025
N2  - Rice production has been recognised as a significant contributor to anthropogenic CH4, a  potent greenhouse gas with a Global Warming Potential (GWP) thirty-four times that of CO2  over a century and eighty-six times greater over two decades (Stavert et al., 2022). Anoxic  conditions from continuous flooding with high organic content in soil promoted the activity  of methanogenic archaea to produce and emit CH4 gas into the atmosphere. Conversely,  methanotrophic bacteria are the biological methane sink by oxidizing CH4 to CO2. Metal  micronutrients, including copper (Cu) and cerium (Ce), serve essential functions as cofactors  for pivotal enzymes implicated in methane oxidation, particularly particulate methane  monooxygenase (pMMO) and lanthanide-dependent methanol dehydrogenase (XoxF MDH). Nevertheless, studies focusing on methane emission flux from rice fields treated with  metal supplements have been limited, and there is insufficient monitoring of CH4 emissions  during the rice growth period. Therefore, this study addresses the current research gap by  examining the effects of Cu and Ce on methanotrophs and methanogenesis in rice paddy  fields through a mesocosm study and the analysis of soil physicochemical parameters and  rice{u2019}s growth indicator. Results demonstrated that CH4 flux ranges from 18.70 to 2481.23 in  units of mg.m-2.hr-1 for the control condition during the 120 days after transplanting. The  metal treatments significantly reduced methane emissions throughout all rice growth stages  compared to the control, particularly during the reproductive phases; the average methane  flux decreased by over 80% under mixed conditions (Cu + Ce). Furthermore, the research  on methane oxidation indicated that the presence of Cu and Ce improved methane  consumption by over 60% during a 72-hour incubation period. Analysis of soil parameters  indicated that metal amendments enhance nutrient availability, particularly nitrogen species,  and simulated rice growth during the vegetative stage.
UR  - http://203.159.5.9/ait-thesis/detail.php?q=B22996
ER  -