为揭示不同生物硝化抑制剂（BNIs）对红壤性水稻土N₂O排放的影响差异及作用机制，通过21 d的土柱淹水培养试验，比较了三种BNIs 1，9-癸二醇（1，9-D）、亚麻酸（LN）和3-（4-羟基苯基）丙酸甲酯（MHPP）与化学合成硝化抑制剂双氰胺（DCD）对土壤N₂O排放及相关硝化、反硝化功能基因的影响。结果表明：不同BNIs （1，9-D、LN、MHPP）可以显著平均降低土壤N₂O日排放峰值40.1%；1，9-D和MHPP可分别抑制N₂O排放总量44.5%和43.9%，而DCD和LN对N₂O排放总量没有显著影响。1，9-D和MHPP对AOA （氨氧化古菌）、AOB （氨氧化细菌）硝化菌和nirS、nirK型反硝化菌的调控均有所不同，1，9-D可以同时抑制AOA、AOB和nirS微生物的生长；MHPP仅可以抑制AOA的生长；其中，AOA-amoA和nirS基因丰度与土壤N₂O的排放呈显著正相关关系。同时，1，9-D和MHPP均增加了nosZ基因丰度及其与AOA-amoA+AOB-amoA、nirS+nirK和AOA-amoA+AOB-amoA+nirS+nirK的比值，且nosZ基因丰度及其相关比值与土壤N₂O排放均呈显著负相关关系。总之，生物硝化抑制剂1，9-D和MHPP引起的AOA-amoA和nosZ基因丰度变化在红壤性水稻土N₂O减排方面发挥了重要的作用。

To reveal the differences in the effects and mechanisms of different biological nitrification inhibitors (BNIs) on N₂O emissions from red paddy soil, a 21-day soil column flooding incubation experiment was conducted to compare three BNIs, 1,9-decanediol (1,9-D), linolenic acid (LN) and methyl 3-(4-hydroxyphenyl)propionate (MHPP) with the chemically synthesized nitrification inhibitor dicyandiamide (DCD) on soil N₂O emissions and associated nitrification and denitrification functional genes. The results showed that the different BNIs (1,9-D, LN, MHPP) significantly reduced peak N₂O emissions by 40.1% on average; 1,9-D and MHPP suppressed total N2O emissions by 44.5% and 43.9%, respectively, while DCD and LN had no significant effects. Both 1,9-D and MHPP differed in their regulations of nitrifying and denitrifying bacteria, with 1,9-D inhibiting the growth of both AOA, AOB, and nirS microorganisms; MHPP only inhibited the growth of AOA; whereas the abundance of AOA-amoA and nirS genes were significant and positively correlated with soil N₂O emissions. Meanwhile, both 1,9-D and MHPP increased nosZ gene abundances and their ratios to AOA-amoA+AOB-amoA, nirS+nirK and AOA-amoA+AOB-amoA+nirS+nirK, which were significantly negatively correlated with soil N₂O emissions. In conclusion, changes in the abundance of AOA-amoA and nosZ genes caused by the biological nitrification inhibitors 1,9-D and MHPP play important roles in N₂O reduction in red paddy soil.

S143.1+6

国家重点研发计划项目（2022YFD1700604）和国家自然科学基金项目（32030099）资助。