Soil microbial communities play an essential role in driving multiple functions (i.e., multifunctionality) that are central to the global biogeochemical cycles. Long-term fertilization has been reported to reduce the soil microbial diversity, however, the impact of fertilization on multifunctionality and its relationship with soil microbial diversity remains poorly understood. We used amplicon sequencing and high-throughput quantitative-PCR array to characterize the microbial community compositions and 70 functional genes in a long-term experimental field station with multiple inorganic and organic fertilization treatments. Compared with inorganic fertilization, the application of organic fertilizer improved the soil multifunctionality, which positively correlated with the both bacterial and fungal diversity. Random Forest regression analysis indicated that rare microbial taxa (e.g. Cyanobacteria and Glomeromycota) rather than the dominant taxa (e.g. Proteobacteria and Ascomycota) were the major drivers of multifunctionality, suggesting that rare taxa had an over-proportional role in biological processes. Therefore, preserving the diversity of soil microbial communities especially the rare microbial taxa could be crucial to the sustainable provision of ecosystem functions in the future.

土壤微生物群落在驱动多种功能（即多功能性）中起着至关重要的作用，而这些功能是全球生物地球化学循环的核心。据报道长期施肥会减少土壤微生物的多样性，但是，人们对施肥对多功能性的影响及其与土壤微生物多样性的关系知之甚少。我们使用了扩增子测序和高通量定量PCR阵列来表征长期实验野外站中经过多次无机和有机施肥处理的微生物群落组成和70个功能基因。与无机肥相比，有机肥的施用提高了土壤的多功能性，与细菌和真菌的多样性均呈正相关。随机森林回归分析表明，罕见的微生物分类群（例如蓝细菌和球菌）而不是主要的分类群（例如变形杆菌和子囊菌）是多功能的主要驱动力，这表明稀有的分类群在生物过程中起着过比例的作用。因此，保护​​土壤微生物群落尤其是稀有微生物分类群的多样性可能对未来可持续提供生态系统功能至关重要。