Dramatic shifts in fungal communities following application of hairy vetch (Vicia villosa Roth L.) in upland of Ultisol

The long-term high intensity continuous cropping with heavy application of mineral fertilization resulted in soil degradation and accumulation of soil-borne plant pathogens. Fungi are key microbial components and closely related to soil health in agroecosystem. In this study, the responses of fungal communities to different agricultural practices were investigated in upland of Ultisol using quantitative polymerase chain reaction (qPCR) and high-throughput sequencing (Illumina MiSeq). The study involved four management treatments: no fertilization (Control), mineral NPK fertilizer (NPK), NPK fertilizer plus peanut straw (NPKS), and NPK fertilizer plus planting green manure (i.e., hairy vetch; NPKG). By comparison with the NPK, application of NPKG significantly increased soil fertility and peanut yield. The NPKS and NPKG significantly increased soil fungal abundance relative to the NPK. Different agricultural practices significantly altered soil fungal community composition in Ultisol. Soil pH and phosphorus content were the two most pivotal drivers shaping fungal community structure. Compared to the NPK, the NPKS and NPKG significantly increased the relative abundance of Basidiomycota. The NPKG increased the relative abundance of certain plant-beneficial fungal taxa and decreased the relative abundance and diversity of plant-pathogen relative to NPK and NPKS, thereby contributing to suppressing continuous cropping barriers and increasing peanut productivity. Overall, our results suggested that planting hairy vetch might outperform NPK or returning peanut straw for improving peanut yield by increasing soil fertility and altering fungal community structure in upland of Ultisol.