Effects and Recovery of Soil Nitrification Following Dimethyl Disulfide Fumigation: Divergent Assembly of Ammonia-Oxidizing Archaea and Bacteria

Soil fumigation is a common practice for controlling soil-borne diseases, yet the ecological recovery and community assembly of key nitrogen-cycling microbes post-fumigation remain unclear. Here, we assess how dimethyl disulfide (DMDS) fumigation influences nitrification and ammonia-oxidizing microbial communities across four agricultural soils. DMDS induced transient ammonium accumulation and delayed nitrate production, reflecting temporary suppression of nitrification. Quantitative PCR and high-throughput sequencing revealed reduced amoA gene abundance and shifts in ammonia-oxidizing archaea (AOA) and bacteria (AOB), with acid soils exhibiting slower recovery. Community assembly analyses uncovered contrasting trajectories: AOA communities shifted from stochastic to deterministic assembly, indicative of increasing environmental filtering, whereas AOB transitioned from deterministic dominance to greater stochasticity during recovery. These divergent patterns reveal taxon-specific ecological strategies driving microbial resilience. Our findings elucidate the transient impacts of DMDS on soil nitrogen cycling and microbial dynamics, emphasizing the critical role of soil physicochemical properties in mediating recovery and informing more sustainable fumigation management.