Effects of Combined Biochar and Chemical Fertilizer Application on Soil Fertility and Properties: A Two-Year Pot Experiment

A two-year pot experiment was conducted to investigate the effects of the combined application of biochar and chemical fertilizer on soil quality and vegetable growth by adding different proportions of chemical fertilizer and biochar to the soil in 2022 and no fertilizer in 2023. It was concluded that the combined treatment improved the soil’s properties. After two consecutive years of planting vegetables, the improvement of soil properties was the most significant with the 1.5 g biochar + 80% chemical fertilizer optimal fertilizer application (BCF6) treatment. In comparison to the control (CK), soil pH, electrical conductivity, and dissolved organic carbon increased by 0.59 units, 166.6%, and 282.6%, respectively. Soil fertility also improved significantly, indicating that the combined treatments resulted in the slow release of nutrients to enhance the effectiveness of the fertilizers. Co-application significantly increased the yield of the edible parts of Chinese cabbage and improved its quality. The most significant effects of vitamin C content and soluble protein were observed in Chinese cabbage under BCF6 treatment, which were 3.33 and 1.42 times more than the CK, respectively. Utilizing biochar as a partial substitute for chemical fertilizers can improve soil structure and fertility over the long term while reducing the reliance on chemical fertilizers, ultimately providing sustained economic and ecological benefits for agricultural production.