Effects Of Rice Husk Biochar And Biochar-Based Fertilizer Application On Soil Enzyme Activities And Bacterial Communities In Continuously Cropped Ginseng

In field experiment, we evaluated the effects of two soil amendments biochar A10 (rice husk biochar) and B10 (mixture of biochar +organic or inorganic fertilizers) applied at 10 t.hm(-2) on the enzymatic activities and bacterial community structures in soils under continuous ginseng cropping (CK) at various sampling dates. A10 and B10 treatments increased the activities of enzymes [soil acid phosphatase (S-ACP), soil sucrase (S-SC), soil catalase (S-CAT) and soil laccase (S-SL)], the highest increase was in S-SL activities. Short-term application of biochar and biochar-based fertilizer decreased the abundances of some soil bacterial groups (Acidobacteria, Chloroflexi, Verrucomicrobia, Myxococcota and Crenarchaeota). The soil enzyme activities had variable effects on the dynamics of different bacterial populations. A10 and B10 treatments increased the relative abundances of Firmicutes, Gemmatimonadota, Bacteroidota and Patescibacteria and decreased the relative abundances of Acidobacteria, Chloroflexi, Verrucomicrobia, Myxococcota and Crenarchaeota. Correlation analysis revealed close relationships between the soil enzyme activities and some soil bacterial populations. The changes in bacterial abundances were also associated with altered soil enzyme activities. In particular, S-ACP and S-SL were key factors associated with bacterial community structures. This study revealed the effects of rice husk biochar and biochar-based fertilizer amendment on soil enzyme activities and microbial community structures in continuous ginseng cropping.