Abstract：
Phosphorus (P) is one of the essential nutrient elements for plant growth and development. Sludge compost products can be used as an important source of soil P to solve the shortage of soil P. The difference in the initial carbon-to-phosphorus ratio (C/P) will lead to difference in the bacterial community, which would affect the biological pathway of P conversion in composting. However, few studies have been reported on adjusting the initial C/P of composting to explore P conversion. Therefore, this study investigated the response of P component transformations, bacterial community and P availability to C/P during sludge composting by adjusting initial C/P. The results showed that increasing C/P promoted the mineralization of organic P and significantly increased the content of the labile P. High C/P also increased the relative content of available P, especially when the C/P was at 45 and 60, it reached 60.51% and 60.47%. High C/P caused differences in the community structure, and improved the binding ability of microbial network modules and the competitiveness of microbial communities. Additionally, high C/P strengthened the effect of microbial communities on the transformation of P components. Finally, the study showed that C/P was the main contributor to P content variation (64.7%) and indirectly affected P component conversion by affecting the microbial community. Therefore, adjusting the C/P is crucial to improve the P utilization rate of composting products.
摘要：
磷(P)是植物生长发育必需的营养元素之一。污泥堆肥产品可以作为土壤P的重要来源，解决土壤P的短缺。初始碳磷比(C/P)的差异会导致细菌群落的差异，这将影响堆肥中磷转化的生物学途径。然而,很少有研究报道调整堆肥的初始C/P以探索P转化。因此,这项研究调查了P成分转化的反应，通过调整初始C/P，污泥堆肥过程中细菌群落和P对C/P的可用性结果表明，C/P的增加促进了有机P的矿化，并显着增加了不稳定P的含量。高C/P也增加了有效P的相对含量，特别是当C/P分别为45和60时，分别达到60.51%和60.47%。高C/P导致群落结构的差异，提高了微生物网络模块的结合能力和微生物群落的竞争力。此外,高C/P增强了微生物群落对P组分转化的影响。最后,研究表明，C/P是P含量变化的主要原因（64.7％），并通过影响微生物群落间接影响P组分的转化。因此,调整C/P对提高堆肥产品的磷利用率至关重要。
