Effects of Swine Biogas Slurry on Arbuscular Mycorrhizal Fungal Community in Poplar Plantations on Northeast China Sandy Soils
Arbuscular mycorrhizal fungi (AMF) are the key symbiotic microorganisms in sandy poplar plantations, regulating vegetation restoration and nutrient cycling. This study aims to investigate the impact of biogas slurry (BS) application on the community structure of AMF in the rhizosphere soil of poplar forests, in order to support the sustainable management of the forest. This study focused on poplar plantations in the sandy areas of Northeast China. High-throughput sequencing technology was utilized to examine the community structure and diversity characteristics of AMF while measuring the physical and chemical characteristics of the soil. The application of BS increased the nutritional status of poplar rhizosphere soil and changed its physical and chemical characteristics, according to the findings. Paraglomus and Glomus dominated the AMF community. The application of BS increased the relative abundance of Glomus in the 0–20 cm and 20–40 cm soil strata. The primary determinants of changes in the dominant AMF populations of poplar were TP, AP, TN, NO3−-N, and pH. To conclude, BS application together with soil depth regulates AMF community composition within sandy poplar plantations. BS amendment ameliorates soil nutrient conditions, increasing subsurface AMF diversity and the relative abundance of vital functional genera. Three core hypotheses were tested: (1) BS application elevates soil carbon, nitrogen and phosphorus concentrations. (2) Biogas slurry and soil depth jointly alter AMF richness and composition. (3) BS-induced shifts in soil nutrients are significantly correlated with AMF community assemblage.