<b>Bacteriophage-bacteria interactions promote ecological multifunctionality in compost-applied soils</b>

Bacteriophages (phages) influence biogeochemical cycling in soil ecosystems by mediating bacterial metabolism. However, the participation of phages in soil’s overall ecological functions (multifunctionality) remains unclear. Hence, this study investigated the potential for phages and bacterial communities to shape the multifunctionality of compost-applied soils. The findings revealed that cow compost and vermicompost applications enhanced the soil’s multifunctionality; consequently, the highest multifunctionality was observed in the soil with vermicompost application (p &lt; 0.05). The composition and diversity of bacteria and phages and the abundance of functional genes of bacteria and phages related to carbon, nitrogen, phosphorus, and sulfur metabolism were dramatically altered following the application of both compost types. Moreover, the impact of phage diversity on soil multifunctionality is crucial for multi-threshold calculations. Structural equation modeling indicated that the effects of bacterial diversity on soil multifunctionality following compost application were paramount, with a path coefficient of 0.88 (p &lt; 0.01). The rise in phage diversity and the enrichment of functional genes indirectly led to a dramatic increase in the soil’s ecological multifunctionality by affecting the host bacteria’s metabolic processes. These results offer a novel avenue to improve soil’s functions and environmental services by transforming the phage community composition and functions of soils.噬菌体（Bacteriophages，以下简称phages）可通过调控细菌代谢过程，影响土壤生态系统的生物地球化学循环。然而，噬菌体在土壤整体生态功能（多功能性，multifunctionality）中的参与机制仍不明晰。为此，本研究探讨了噬菌体与细菌群落调控施用堆肥土壤多功能性的潜力。研究结果显示，施用牛粪堆肥与蚯蚓堆肥均可提升土壤多功能性；其中蚯蚓堆肥处理组的土壤多功能性最高（p < 0.05）。两种堆肥施用后，细菌与噬菌体的群落组成、多样性，以及参与碳、氮、磷、硫代谢的细菌与噬菌体功能基因的丰度均发生显著改变。此外，噬菌体多样性对土壤多功能性的影响在多阈值计算中具有关键意义。结构方程模型（Structural equation modeling）分析表明，堆肥施用后细菌多样性对土壤多功能性的影响最为显著，路径系数达0.88（p < 0.01）。噬菌体多样性的提升与功能基因的富集，可通过调控宿主细菌的代谢过程，间接推动土壤生态多功能性的显著提升。本研究结果为通过调控土壤噬菌体群落组成与功能，进而改善土壤生态功能与环境服务功能提供了全新思路。