Untreated chicken manure causes a large amount of antibiotics and heavy metals to enter the soil environment. Currently, there is limited research on antibiotic resistance genes (ARGs) and heavy metal resistance genes (HMRGs) in soil profile. In this study, we conducted a preliminary investigation on the soil profile of vegetable field contaminated by chicken manure. The results showed that the absolute abundance of some resistance genes was higher at the 20–60 cm. Subsequently, we further analyzed the vertical migration of bacteria bearing ARGs and HMRGs through a soil profile as affected by manure using metagenomic sequencing. The findings revealed that long-term application of chicken manure significantly increased the alpha (α) diversity of the 0–20 cm soil layer ARGs and HMRGs, the plasmids relative abundance of soil profile substantially increased. Furthermore, long-term application of chicken manure changed the community composition of the 0–20 cm soil layer resistance genes, and also affected the community composition of the 20–40 cm soil layer with the increase of manure rates. Additionally, long-term application of chicken manure significantly increased the α diversity of the 0–20 cm soil layer bacteria. Structural equation modeling (SEM) further analysis revealed that bacterial relative abundance was the primary driving factor for the distribution of ARGs in vertical space, while mobile genetic elements (MGEs) were the main driving factor for HMRGs. This study strengthens our understanding of the vertical spatial distribution of soil resistance genes following long-term application of chicken manure, and also provides the basis for the management of subterranean environment.

未经处理的鸡粪会导致大量抗生素和重金属进入土壤环境。目前，对土壤剖面中抗生素耐药基因 （ARGs） 和重金属耐药基因 （HMRG） 的研究有限。在本研究中，我们对受鸡粪污染的菜地土壤剖面进行了初步调查。结果表明，一些抗性基因的绝对丰度在 20-60 cm 处较高。随后，我们使用宏基因组测序进一步分析了携带 ARGs 和 HMRGs 的细菌通过受粪污影响的土壤剖面的垂直迁移。结果表明，长期施用鸡粪显著提高了 0–20 cm 土层 ARGs 和 HMRGs 的 α （α） 多样性，质粒在土壤剖面中的相对丰度显著增加。此外，长期施用鸡粪改变了 0–20 cm 土层抗性基因的群落组成，并且随着粪污用量的增加，也影响了 20–40 cm 土层的群落组成。此外，长期施用鸡粪显著增加了 0–20 cm 土层细菌的α多样性。结构方程模型 （SEM） 进一步分析表明，细菌相对丰度是 ARGs 在垂直空间分布的主要驱动因素，而移动遗传元件 （MGEs） 是 HMRGs 的主要驱动因素。这项研究加强了我们对鸡粪长期施用后土壤抗性基因垂直空间分布的理解，也为地下环境的管理提供了依据。