Inefficient-looking composting promotes the elimination of guild-plant pathogens fungi in vegetable wastes

The carbon to nitrogen (C/N) ratio is an important factor determining composting efficiency, while the relationships among relative abundance of guild-plant pathogens fungi, compost maturation index and microbial community variation influenced by C/N ratio during vegetable waste composting still remain limited. To address this, fungal communities during the composting processes with C/N ratio of about 15 (CN15) and 25 (CN25) with vegetable waste as main raw materials were analyzed. Compared to CN25, CN15 showed the faster microbial community variation and the better compost maturation index overall the composting process. Nevertheless, CN25 revealed the higher falling range in eliminating guild-plant pathogens fungi than CN15.Notably, relative abundance of guild-plant pathogens fungi was significantly negatively related to compost maturity index in CN25 treatment, while no significant relationship was observed in CN15 treanment. This study suggests that the inefficient-looking composting with slow temperature rising in the early stage is beneficial to kill guild-plant pathogens fungi in vegetable waste.

碳氮比（carbon to nitrogen，C/N）是影响堆肥效率的关键因素，在以蔬菜废弃物为原料的堆肥过程中，功能群植物病原真菌（guild-plant pathogens fungi）的相对丰度、堆肥腐熟度指标与受碳氮比调控的微生物群落变化三者间的关联研究仍较为匮乏。为厘清该研究缺口，本研究以蔬菜废弃物为主要原料，设置碳氮比分别约为15（记为CN15）与25（记为CN25）的两组堆肥体系，分析了其堆肥全过程中的真菌群落结构。相较于CN25组，CN15组在整个堆肥周期内展现出更快的微生物群落演替速率，且整体堆肥腐熟度表现更优。不过，CN25组在清除功能群植物病原真菌过程中，其相对丰度的降幅显著高于CN15组。值得注意的是，在CN25组中，功能群植物病原真菌的相对丰度与堆肥腐熟度指标呈显著负相关，而CN15组未观测到此类显著关联。本研究表明，前期升温缓慢、表观效率偏低的堆肥工艺，更利于杀灭蔬菜废弃物中的功能群植物病原真菌。