长期粪肥替代部分化肥对红壤细菌群落的影响OA

Long-term fertilization management significantly affects nutrient characteristics and microbial community structure in Ultisols.However,the ecological effects of manure substitution under different mineral nutrient backgrounds remain poorly understood.Based on a 21-year long-term field experiment,six treatments were established:nitrogen only(N),nitrogen-phosphorus(NP),and nitrogen-phosphorus-potassium(NPK),along with their corresponding manure-substi-tuted treatments(NM,NPM,and NPKM).This study investigated the effects of manure substitu-tion on bacterial communities in Ultisols.The results showed that manure substitution significantly increased soil pH and available phosphorus content,while enhancing bacterial α-diversity exclusive-ly under the N treatment.Both mineral fertilization and manure substitution significantly affected bacterial community structure.Bacterial community assembly was predominantly driven by stochastic processes,with manure substitution further enhancing stochasticity under nutrient regimes with sim-plified fertilizer inputs.Therefore,the regulatory effects of manure substitution on bacterial commu-nities in Ultisols exhibit clear nutrient-background dependence,providing scientific evidence for fer-tilizer management in red soil regions.