长期施肥对水稻土典型氨氧化菌和全程氨氧化菌种群活性和丰度的影响OA北大核心CSTPCD

[Objective]This work aimed to investigate the impact of long-term applying organic and inorganic fertilizers on the abundance and activities of complete ammonia oxidizers(Comammox),ammonia-oxidizing archaea(AOA)and bacteria(AOB),as well as the abundances of Nitrospira and Nitrobacter in paddy soil,providing a scientific basis for mitigating greenhouse gas emissions and promoting sustainable agricultural production.[Method]By utilizing multiple specific inhibitors(i.e.,acetylene,1-octyne,and DMPP)in conjunction with real-time quantitative PCR(qPCR),this work examined the differences in activities and abundances of Comammox,AOA,and AOB as well as the abundances of Nitrobacter and Nitrospira in a paddy soil under four fertilization regimes:plots without fertilizer(CK),with manure(M),with chemical fertilizer(NPK),and with combination of manure and chemical fertilizer(MNPK).[Result]The long-term application of organic fertilizer significantly stimulated the activities of Comammox and AOA(Two-way ANOVA,P＜0.001).In those plots solely receiving organic manure,Comammox accounted for as high as 64.2% of total ammonia oxidizing activity,while the inorganic fertilizer application only enhanced the activity of AOB(Two-way ANOVA,P＜0.001).qPCR demonstrated that chronic organic amendment significantly increased the abundances of AOA,Nitrospira,Comammox clade A and Clade B(Two-way ANOVA,P＜0.001);whereas inorganic amendment increased the abundances of AOB and Nitrobacter(Two-way ANOVA,P＜0.001).The correlation analysis revealed there were positive correlations between activities of AOA and Comammox with moisture content,organic matter(OM),total nitrogen(TN),total phosphorus(TP),available phosphorus(AP),alkaline hydrolysable nitrogen(AN),as well as AOA and Nitrospira abundances,while the activity of Comammox was positively correlated with the abundance of Comammox clade A as well.Additionally,the activity of AOB showed positive correlations with AOB and Nitrobacter abundances,nitrate content,and available potassium(AK).[Conclusion]Comammox played an important role in nitrification of the tested paddy soil,with its abundance and activity primarily influenced by the changes in moisture content,OM,TN,TP,AP,and AN etc..