農耕地からのメタン・一酸化二窒素の排出はどこまで明らかになったか

抄録

Objective. This paper overviews current knowledge on emissions of methane（CH₄）and nitrous oxide（N₂O）from agricultural land.

Results and Discussion. Agricultural land use is identified to be a major source for atmospheric CH₄ and N₂O. It is pointed out that extended cultivation of paddy rice and dramatic increase in the consumption of fertilizer nitrogen have been significantly increased emission rates of CH₄ and N₂O, respectively. An emission database of rice fields in Asian countries were compiled and analyzed by a statistical approach. A large number of field measurements for CH₄ and N₂O conducted at various sites in the world was compiled as databases. Statistical analysis of these databases developed methodologies for estimating regional and global emission rates, such as those in the IPCC Guidelines. Results of the field measurement experiments also suggested promising mitigation options for agricultural emissions of CH₄ and N₂O.

Conclusions. The review of the research advance indicates the effects of agricultural emissions of CH₄ and N₂O on global warming and the potentials of mitigation options. Further studies and actions are needed to develop practical systems for extending the mitigation options to local farmers.