Biochar-based organic fertilizer application rates forTetrastigma hemsleyanumplanted under Moso bamboo

The under-forest economy has received increased attention in China. However, little is known about the effects of co-composted biochar on soil and plant biomass in under-forest planting systems. In this study, plant biomass, soil nutrient levels, and bacterial communities were evaluated after application of biochar-based organic fertilizer (BOF, derived from co-composted biochar-compost) at varying rates to soils supportingTetrastigma hemsleyanumDiels & Gilg planted under a Moso bamboo (Phyllostachys edulis) forest. BOF treatment increased the biomass ofT. hemsleyanum. Compared with the control, BOF application significantly increased soil pH and organic carbon (SOC). The high-throughput sequencing results showed significant differences in the Bacteroidetes, Verrucomicrobia, Chlorofexi, and OD1 phyla among all groups. At the genus level, the control group was characterized by a preponderance ofConexibacter.Rhodanobacterwas enriched in soils with a 3% BOF application andSteroidobacterandSpirochaetawere the most prominent phyla in the 5% BOF group. There was no biomarker selected in the 1% BOF group at the genus level. In conclusion, BOF application increased the biomass ofT. hemsleyanumwhen intercropped under a Moso bamboo forest; this effect may be due to changes in the soil physicochemical properties and microbial communities after BOF application.