Bacillus subtilis SL-13 biochar formulation promotes pepper plant growth and soil improvement

The use of microbial fertilizers can help to avoid the harmful effects of traditional agricultural fertilizers and pesticides; however, there are many constraints on the practical application of such fertilizers. In this study, microbial biochar formulations (MBFs) were obtained by loading biochar, created from agricultural waste, with Bacillus subtilis SL-13. The effects of the MBF on pepper plant growth and soil fertility were studied in pot experiments. The MBF improved the soil texture and environment and favored plant growth. Compared with B. subtilis SL-13-only and biochar-only treatments, the MBF treatments exhibited a significant increase in pepper plant growth and physiological indices and a significant improvement in the physical–chemical properties and activities of several enzymes in the soil. Therefore, the present study demonstrated that MBFs not only retain the beneficial effect of biochar in improving the soil properties but also improve the performance of B. subtilis SL-13 in promoting plant growth.