长期氮磷施肥对黑土氨氧化微生物丰度及硝化潜势的影响OA

This study investigates the effects of long-term fertilization on the abundance of am-monia-oxidizing microorganisms and potential nitrification rate in black soil,based on a long-term(40 years)fertilization experiment in Northeast China.Soil samples were collected from four treat-ments,including no nitrogen fertilizer(CK),nitrogen fertilizer only(N),phosphorus fertilizer only(P),and combined nitrogen-phosphorus fertilizers(NP),over three consecutive years(2021-2023).The abundance of ammonia-oxidizing microorganisms was quantified via real-time quantitative PCR,and the soil potential nitrification rate was measured using the chlorate inhibition method.The results showed that both N and NP treatments significantly decreased the abundance of ammonia-oxi-dizing archaea,comammox Nitrospira Clade B,and the soil potential nitrification rate,while signifi-cantly increasing the abundance of ammonia-oxidizing bacteria,comammox Nitrospira Clade A,and soil NO3--N content.The P treatment had no significant effect on the abundance of ammonia-oxidizing microorganisms,but significantly increased the soil potential nitrification rate.Correlation analysis in-dicated that the abundance of ammonia-oxidizing archaea was the dominant biotic factor influencing the soil potential nitrification rate,while soil pH was the main environmental factor.In conclusion,long-term fertilization regulates soil nitrification in black soil by altering the abundance of ammonia-oxidizing microorganisms and soil pH.