Abstract:The original soil columns of a typical single-cropping paddy field in the Taihu Lake Basin were used as the research object, N2O emission, rice yield and soil physiochemical properties were monitored under the application of three straw types (rice straw-RS, wheat straw-WS and maize straw-MS), and the abundances of multiple functional genes related to N2O emission were quantified to clarify soil microbial mechanism of N2O emission under different straw types. The results showed that RS, WS and MS treatments increased N2O emissions by 162.32%, 107.11% and 9.48%, respectively, in which RS was significantly higher than those from MS treatment. The abundance of ammonia oxidizing bacteria and ammonia oxidizing archaea (AOA, AOB) and denitrifiers communities (nirS, nosZ) all showed a similarly change, increasing first and then decreasing with rice growth. Compared with CK treatment (no straw), RS treatment significantly increased the abundances of AOA, AOB, nirS and nosZ by 6.14, 8.26, 4.82 and 16.96 times in the elongation stage, respectively, while no significant response was found in either MS or WS treatment. Soil NH4+-N content was generally higher than NO3--N during rice growth, with an increasing pattern until the tillering stage, and then decreased with rice growth, while no significant difference was found among different straw treatments. The results of correlation analysis and the Structural Equation Modeling (SEM) showed that AOB abundance and soil NH4+-N content were the main factors affecting N2O emission in paddy field. Considering the comprehensive results of soil physiochemical properties, rice yield and soil microbial abundance, maize straw is the most appropriate for N2O emission mitigation and yield enhancement of single-cropping paddy field in the Taihu Lake Basin.