Impact of Interaction between Biochar and Soil Microorganisms on Growth of Chinese Cabbage by Increasing Soil Fertility

We investigated the improvement of cabbage growth through the interaction of biochar, which can promote microbial activity, with the microbes in the soil. An increase in cabbage growth could be detected in soil with biochar or soil microbes, but the fresh weight of cabbage in soil supplemented with both biochar and microbes was 8.8% and 5% higher, respectively, than that with either microbes or biochar alone. The phosphorus content in Chinese cabbage was also increased by 36.3% when compared with the control without the addition of biochar and microbes. Such an improvement on cabbage growth is closely related to the soil amelioration. The application of biochar in soil significantly stimulated the growth of soil microbes and further altered the microbial community structure in soil. When 2% biochar and microbes were simultaneously applied in soil, the content of the organic matter and available phosphorus content in soil was 36.7% and 45.5% higher, respectively, than that in soil with or without biochar. The maximal increment in the available potassium content was observed in the soil supplemented with both 5% biochar and soil microbes, which was 46.4% higher than that in soil without the addition of biochar and microbes. Both phosphatase and urease activity in soil were also increased by 61.2% and 49.4%, respectively, by applying 2% biochar in soil together with microbes, as the interaction of biochar with the microbes could promote the activity of soil microbes and enzymes which resulted in an improvement in soil fertility. The interaction of biochar with microbes in soil could promote the plant growth of Chinese cabbage by increasing the soil fertility.