Methane Emission from Paddy Fields and its Mitigation Options on a Field Scale

Abstract

Rice is one of the most important cereals, especially in Asian countries. Methane (CH4), one of the major greenhouse gases, is emitted from flooded paddy fields as a result of phenomena on various scales. This paper review studies on CH4 emission from paddy fields, paying special attention to mitigation options from the viewpoint of their feasibility on a field scale. Field management of rice paddies is primarily carried out to obtain suitable rice yields, but it also has physical, chemical, and biological effects on CH4 emission. Therefore, some management practices can be win-win options that sustain rice yield and mitigate CH4 emission. For example, appropriate water management for rice growth and yield is also effective in decreasing CH4 emission. Other practices, such as nitrogen fertilizer application and organic matter application can also have positive effects on rice yield and CH4 emission. Recent microbial studies have been revealing the ecology of methanogens and methanotrophs in paddy soils. Further studies on a microbial scale will offer additional clues to the mitigation of CH4 emission from paddy fields.

Peatland geoengineering: an alternative approach to terrestrial carbon sequestration

“…Phenol oxidase activity is particularly sensitive to low pH [57,58] and will have indirect effects on hydrolase enzymes by allowing the accumulation of higher levels of inhibitory phenolic compounds. Indeed, the effects of ammonium sulfate, a physiological acid fertilizer, can increase wetland rice productivity while decreasing decomposition [59]. .…”

“…Similarly, the effect of nitrogen applied as amino acids warrants research, because plants (including bryophytes) that are able to use amino acids directly from the soil may have a competitive advantage in these low-nitrogen ecosystems [68]. Application of ammonium sulfate, a physiological acid fertilizer, has been shown to increase wetland rice productivity while decreasing decomposition [59] and therefore could be investigated along with liming (addition of CaCO 3 ) to raise the pH. Finally, soil amendments could also be investigated to promote NPP.…”

MethanogenesisversusElectrogenesis: Morphological and Phylogenetic Comparisons of Microbial Communities

“…[1][2][3] Since methane is known as a green-house gas, its emission is of environmental concern. [3][4][5] Studies have analyzed microbial populations involved in methane emission from rice paddy fields, 6,7) lake sediment 8,9) and contaminated environments. 10,11) Among these, since methane emission from rice paddy fields is enormous, 4,5) the microorganisms involved in methanogenesis in rice paddy fields are of particular interest.…”

“…[3][4][5] Studies have analyzed microbial populations involved in methane emission from rice paddy fields, 6,7) lake sediment 8,9) and contaminated environments. 10,11) Among these, since methane emission from rice paddy fields is enormous, 4,5) the microorganisms involved in methanogenesis in rice paddy fields are of particular interest. 6,7,12) Another important aspect of methanogenesis is that it is widely utilized in bioreactors treating organic waste and in conserving energy from them.…”

Relationships between methane emissions and soil microorganisms in a double-rice field in southern subtropical China

“…Methane (CH 4 ) is the most important non-carbon dioxide (CO 2 ) greenhouse gas (GHG) and the key contributor of greenhouse effect in double-rice fields (Akiyama et al 2005;Minamikawa et al 2006). The concentrations of the atmospheric methane has been increasing since the industrialization, and, to date, the annual increase rates of methane can still not be neglected, i.e.…”