Effects of Tobacco Stem-Derived Biochar on Soil Properties and Bacterial Community Structure under Continuous Cropping of Bletilla striata

Biochar has been shown to promote the growth of crops under continuous cropping. It has been proposed that biochar could improve soil properties and alter bacterial community structure, which however remains to be validated. This study aims to investigate the effects of tobacco stem-derived biochar on soil properties, bacterial community structure, and the growth of Bletilla striata , a traditional Chinese medicinal herb, under continuous cropping. Tobacco stem-derived biochar was applied at 0.00, 3.00, and 7.50 t·ha −1 to the soil after 8-year continuous cropping of B. striata . Soil pH, nutrient availability, enzyme activity, and the growth of B. striata were investigated after transplanting for 6 months. Further, the bacterial community structure was analyzed within the metagenomic framework through high-throughput DNA sequencing. Soil pH, electrical conductivity, available nitrogen, available phosphorus, and available potassium increased significantly with biochar application ( P