As the global leader in rice production, China’s paddy fields contribute substantially to greenhouse gas emissions through methane (CH₄) and nitrous oxide (N₂O) releases. Aromatic rice cultivation practices have been optimized to enhance the aroma, so the relationship between its cultivation and greenhouse gas emissions from paddy fields is unclear. To investigate how aroma-enhancing cultivation practices drive microbial community dynamics in aromatic rice paddies and their implications for greenhouse gas emissions, a two-year experiment in five ecological locations (Xingning, Nanxiong, Conghua, Luoding, and Zengcheng) compared two farming practices: partial organic substitution for inorganic fertilizers combined with water-saving irrigation (IOF+W) and traditional cultivation (CK). The CH₄and N₂O emissions, soil microbial composition and function, global warming potential (GWP), nitrogen use efficiency, yield, and the content of 2-acetyl-1-pyrroline (2-AP) were measured and analyzed. The main purpose was to investigate the impact of IOF+W on CH₄and N₂O emissions and their relationship with soil microorganisms. The results showed that IOF+W significantly reduced CH₄emission fluxes and totals (36.95%) and GWP (31.29%), while significantly increasing N₂O emission fluxes and totals (14.82%). The soil microbial community structure was reshaped by the IOF+W treatment, which suppressed methanogens but enhanced the abundances of nitrifying and denitrifying bacteria. Key enzymatic activities involved in CH₄production, such as methyl-coenzyme M reductase, formylmethanofuran dehydrogenase, and methyltransferase, decreased. In contrast, the activity of the key CH₄-oxidizing enzyme methanol dehydrogenase increased.This shift led to an overall attenuation of the CH₄production metabolism while enhancing the CH₄oxidation metabolism. In addition, the activities of pivotal enzymes involved in denitrification and nitrification were improved, thus enhancing nitrogen nitrification and denitrification metabolism. Moreover, the IOF+W treatment significantly increased nitrogen use efficiency (47.83%), yield (14.77%), and 2-AP content (13.78%). Therefore, the IOF+W treatment demonstrated good efficacy as a sustainable strategy for achieving productive, green, resource-efficient, and premium-quality aromatic rice cultivation in South China.

long-term manure amendment  /  N₂O emission  /  nitrogen mineralization  /  denitrification  /  (nirK+nirS)/nosZ