<p><UnorderedList Mark="Bullet"> <ItemContent> <p>The pantropic invasive earthworm exacerbates soil N leaching and N₂O emission.</p> </ItemContent> <ItemContent> <p>AMF inoculation suppresses soil nitrification and denitrification processes.</p> </ItemContent> <ItemContent> <p>AMF inoculation could mitigate soil N loss induced by the earthworm.</p> </ItemContent> </UnorderedList></p><p>Invasive earthworms can exacerbate soil N leaching and N₂O emissions, particularly in disturbed habitats with high populations. While earthworms and arbuscular mycorrhizal fungi (AMF) can synergistically influence plant N uptake, it remains unclear whether AMF inoculation can mitigate earthworm-induced N loss. We conducted a two-way factorial microcosm experiment to evaluate the effects of the pantropical earthworm <i>Pontoscolex corethrurus</i> and AMF (<i>Rhizophagus intraradices</i>) on soil N leaching and N₂O fluxes. We further employed ¹⁵NH₄¹⁵NO₃ labeling and qPCR to assess associated changes in nitrification and denitrification processes. <i>P. corethrurus</i> increased both N leaching and N₂O emissions, whereas AMF inoculation significantly reduced N₂O emissions and NH₄⁺ leaching. The ¹⁵N₂O patterns matched total N₂O fluxes, suggesting emissions primarily derived from nitrification and denitrification. Abundance of nitrification- (<i>amoA, amoB</i>,) and denitrification-related genes (<i>nirK, nirS, nosZ</i>) showed positive correlations with soil NH₄⁺ concentration and N₂O emissions, indicating that microbial functional potential is closely linked to inorganic N availability and N₂O emissions. AMF reduced these gene abundances, particularly in the rhizosphere, consistent with decreased NH₄⁺ leaching and N₂O emissions. These findings highlight the ecosystem risks posed by <i>P. corethrurus</i> and suggest AMF inoculation represents a promising strategy to mitigate earthworm-induced N₂O emissions in tropical and subtropical regions.</p>