硝化抑制剂DMPP对滨海盐碱水稻土细菌群落的影响OA

[Objectives]This study aimed to investigate the effects of nitrification inhibitor(3,4-dimethylpyrazole phosphate,DMPP)on bacterial community diversity,structure,and assembly mechanisms in coastal saline-alkaline paddy soils.[Methods]A pot experiment combined with 16S rRNA gene amplicon high-throughput sequencing was conducted to analyze the impacts of DMPP application on bacterial community structure and assembly processes in soils with two salinity levels.[Results]Compared with low-salinity soil,high-salinity soil exhibited lower Shannon index and reduced community stability.DMPP application increased Shannon and Chao1 indices while enhancing community stability in high-salinity soil,whereas it decreased these indices and stability in low-salinity soil.Significant structural differences were observed between soil treatments.High-salinity soil showed lower relative abundances of Myxococcota and Acidobacteriota but higher abundances of Proteobacteria and Bacteroidota compared to low-salinity soil.DMPP addition significantly reduced Bacteroidota and Chloroflexi abundances while increasing Actinobacteria and Proteobacteria abundances.Stochastic processes predominantly governed bacterial community assembly.DMPP amplified the relative contribution of stochasticity in high-salinity conditions but reduced it under low-salinity conditions.Redundancy analysis and correlation analysis revealed that soil electrical conductivity(P<0.001),organic matter(P<0.01),and available nitrogen(P<0.001)were key environmental factors influencing bacterial community structure.[Conclusions]DMPP application significantly altered bacterial communities in coastal saline-alkaline paddy soils with varying salinity levels.This study provides theoretical foundation for enhancing nitrogen utilization efficiency in coastal saline-alkaline ecosystems.