Rhizosphere microorganisms can affect the nutrient uptake of plant roots, and therefore contribute significantly to plant growth and nutrient cycling in forest ecosystems. Our previous studies revealed that the application of biogas slurry, an available organic fertilizer, increased the signal intensity and diversity of functional microbial genes in bulk soil. Further study of the response of rhizosphere soil microbial community structure to biogas slurry fertilization is of great significance for elucidating the mechanisms of nutrient cycling in forest ecosystems. In this study, our aim was to investigate the effects of biogas slurry application at different concentrations (Control, no treatment; Low, 250 m³ ha⁻¹ yr⁻¹; High, 375 m³ ha⁻¹ yr⁻¹) on the microbial community structures in the rhizospheric soil of poplar plantations. We found that the treatments with the highest biogas slurry concentration had the greatest fungal community Shannon diversity and richness. Among these, the Shannon diversity of rhizospheric soil fungal communities increased significantly with the high-concentration biogas slurry treatment compared with the control. However, the Shannon index of bacterial communities in rhizospheric soil exhibited negligible changes with the addition of biogas slurry. Further analyses revealed that the relative abundance of the fungal community in rhizospheric soil significantly changed in response to the quantity of biogas slurry. In particular, the abundance of several functional fungi, that play important roles in plant growth, significantly altered with the application of biogas slurry. These may be due to the changes of rhizosphere soil physicochemical properties, such as C/N ratio and available P, caused by biogas slurry application. Our results suggest that fertilization with biogas slurry can elevate fungal community diversity, but not bacterial diversity, in rhizospheric soil.

根际微生物可以影响植物根系对养分的吸收，因此对森林生态系统中的植物生长和养分循环有重要贡献。我们之前的研究表明，沼液（一种有效的有机肥料）的施用增加了大块土壤中功能微生物基因的信号强度和多样性。进一步研究根际土壤微生物群落结构对沼液施肥的响应，对于阐明森林生态系统养分循环机制具有重要意义。在这项研究中，我们的目的是研究不同浓度的沼液施用的影响（对照，未处理；低，250 m ³  ha ^-1  yr ^-1；高，375 m ³ 公顷^-1 年^-1) 对杨树人工林根际土壤微生物群落结构的研究。我们发现沼液浓度最高的处理具有最大的真菌群落香农多样性和丰富度。其中，与对照相比，高浓度沼液处理后根际土壤真菌群落的香农多样性显着增加。然而，随着沼液的添加，根际土壤中细菌群落的香农指数变化可以忽略不计。进一步分析表明，根际土壤中真菌群落的相对丰度随着沼液量的变化而显着变化。特别是，在植物生长中发挥重要作用的几种功能性真菌的丰度，沼液的应用显着改变。这可能是由于施用沼液引起的根际土壤理化性质的变化，如C/N比和有效P。我们的研究结果表明，沼液施肥可以提高根际土壤中的真菌群落多样性，但不能提高细菌多样性。