Different contribution of species sorting and exogenous species immigration from manure to soil fungal diversity and community assemblage under long-term fertilization

Impacts of manure application on the soil fungal community in agricultural systems have been extensively explored. However, the contribution of manure-sourced exogenous species in shaping soil fungal diversity and community assemblage are still open questions. In this study, fungal communities in soils that received manure with or without chemical fertilizers, as well as a no fertilizer control, were characterized using high throughput sequencing. We found that diverse taxa in manure, including some potential pathogens, were transmitted into soil through manure application, accounting for 9.80-10.94% of soil fungal richness, but only for 1.10-2.04% in the relative abundance of soil fungal community. Manure application impacted soil fungal community assemblage mainly through alterations of soil characteristics, especially soil carbon pool. Nutrients from manure showed great selection on fungal taxa, thus strengthening the effect of niche filtering on fungal community. As a consequence, manure application resulted in lower fungal richness than chemical fertilizers through enhancing species extinction. These findings suggested that the transmission of manure-sourced exogenous species is a key source of fungal richness but contributed little to soil fungal community assemblage. Manure incorporation structured soil fungal diversity and community assemblage primarily through changing niche breadth and the types of substrates available in the soil.