Effects of biogas slurry and conventional fertilizer on the abundance, diversity, and function of the soil microbe community in continuously cropped Chinese chives

The effects of biogass slurry and conventional chemical fertilizer as topdressings on relative abundance and community diversity of soil microbes in fields under continuous cropping of Chinese chives were investigated. It was found that topdressing treatment altered soil bacteria community and diversity, where relative abundance and taxonomic diversity were greater in the biogas slurry treatment. Although average well color development was higher in the conventional fertilizer treatment than in the biogas slurry treatment and the control, indicating improved functional diversity of the carbon-using soil microorganism community, taxonomic diversity decreased (Shannon diversity and Chao 1 indexes). Of 24 bacterial genera that had a relative abundance greater than 1%, it was found that relative abundance of Saccharibacteria_genera_incertae_sedis and Gp6 was correlated with soil organic matter content (r = 0.804, P < 0.01 and r = -0.85, P < 0.01, respectively). The organic matter content in biogas slurry is richer than fertilizer. The result showed that biogas slurry as topdressings may be a useful biological fertilizer in sustainable continuous cropping systems. Key words: Bacterial community, biogas slurry, Chinese chives, continuous cropping.