Dynamic of fungal community composition during maize residue decomposition process in north-central China

Abstract

Crop residue decomposition is a process largely mediated by soil microbes. This study aimed to investigate the dynamic of crop residue decomposition, change in fungal community composition and extracellular enzymatic activity in maize (Zea mays L.) residue via utilization of a two-year residue-bags study in north-central China. After the residue was buried in soil, the cumulative residue mass loss rate was 33%, 74%, and 85% after 2, 12, and 24 months, respectively. Total fungal abundance and the activities of beta (β)-glucosidase, β-d-cellobiosidase, and β-xylosidase were greater at the initial stage of decomposition and gradually decreased over time. However, the phenol oxidase activity presented an opposite pattern relative to the hydrolytic enzymes. The fungal community composition was similar in the residue during the initial (0) and 2 months after, with the phylum Ascomycota (classes Sordariomycetes and Dothideomycetes) dominating the community composition for the first two months but then decreased gradually over time. Phyla Basidiomycota, Cercozoa, and classes Eurotiomycetes and Tremellomycetes presented an increasing-decreasing trend during the decomposition process. The phylum Zygomycota (class Leotiomycetes) gradually increased over time and showed greater abundance at the later stage of decomposition; while the fungal community composition was similar in soil and residue samples for the 20–24 months. This study highlights the relevancy of fungal abundance for playing a critical role in residue decomposition, with the composition of this community changing from the dominance of copiotrophic populations in the early stage to oligotrophic populations in the later stage.