Straw biochar strengthens the life strategies and network of rhizosphere fungi in manure fertilized soils

Abstract

Soil fungi have many important ecological functions, however, their life strategies and interactions in manure fertilized soils are not well understood. The aim of this study was to investigate the effects of biochar amendment on the fungal life strategies and species interactions in ryegrass (Lolium perenne L.) rhizosphere soil by high-throughput sequencing. Three soil treatments were evaluated: soil and pig manure mixture without planting ryegrass and biochar application (bulk soil), mixture with ryegrass planting (rhizosphere soil (RS)), and addition of 2% (w/w) biochar with ryegrass (RS + biochar). Our results indicated that temporal turnover, defined as the slope of linear regression between community similarity and time, was significantly higher in the biochar amendment (slope = −0.2689, p < 0.0001) relative to the rhizosphere soil. Following biochar addition, the percentage of species employing slow acclimation ecological strategies decreased (from 27% to 17%) and the percentage of sensitive species increased (from 40% to 50%) in comparison to the rhizosphere soil. Network analysis indicated that fungal communities in the biochar amendment enhanced positive correlations compared to the rhizosphere soil and bulk soil. Structural equation model indicated that soil pH was the most important factor in altering fungal life strategies and interactions in manure fertilized soils.