BACKGROUND: Biochar affects soil fertility and nutrient cycling. Also, there could be an effect on the characteristics of crops grown on biochar applied soil, and there is much use of biochar with commercial vegetable seedlings.
METHODS AND RESULTS: The objective of this study was to investigate the effects of the biochar content of seeding mixes on early growing of lettuce (Lactuca sativa L.), Chinese cabbage (Brassica rapa L.), and red pepper (Capsicum annuum L.). Treatments consisted of a control (0 : 1, ratio of biochar to seeding mixes (w/w)), 1 : 9 (biochar 10%), 3 : 7 (biochar 30%), 5 : 5 (biochar 50%), and 7 : 3 (biochar 70%). The plant height, leaf number, and dry weight of lettuce, Chinese cabbage, and red pepper were all in the order of biochar 50%, 30%, 10%, control, and 70% with significant differences for these characteristics for lettuce and red pepper seedlings. Increasing content of biochar (10%, 30%, and 50%) progressively activated growing of lettuce, Chinese cabbage, and red pepper, but at 70% treatment growth was retarded. For red pepper, there were differences in nutrition content compared with lettuce at 90 days after sowing with the content of K of red pepper seedlings increasing in accordance with the biochar content while the content of P, Ca, and Mg decreased.
CONCLUSION: I In conclusion, adding biochar to seeding mixes is considered to be an important measure for growing healthy seedlings and carbon sequestration. More field experiments are needed to verify the effect of biochar on crop growth over the entire growing season.