Effect of Biochar derived from Coffee sludge on growth of Chinese cabbage (Brassica campestris l. Ssp.pekinensis) in field soil and bed soil

Biochar is the carbon solid produced through the pyrolysis of biomass from organic sources such as agricultural waste, animal manure, and sludge under limited or anaerobic conditions. It is known to function as a soil amendment, affecting water and nutrient retention, soil acidification, and active growth of soil microorganisms. This experiment was conducted to evaluate the application of biochar on the growth characteristics of Chinese cabbage at Chungnam National University in Daejeon, Korea from December 28,2016 to February 22,2017. Coffee sludge was used to produce biochar through pyrolysis, which was then applied at 0%, 2%, and 5% to field soil and bed soil. In field soil, the Chinese cabbage with 5% treatment of coffee sludge biochar had the highest fresh weight (116.46 ±1.3 g/plant) and as the content of biochar increased, the number of leaves that appeared also increased. In bed soil, the Chinese cabbage with 2% coffee sludge biochar treatment had the highest fresh weight (209.35 ± 13.8 g/plant). Compared to the control, biochar treatments resulted in increased number of leaves, leaf length, and leaf width. The organic matter in field soil under 5% coffee sludge biochar treatment was 7.1 ± 0.44%, whereas it was 1.0 ± 0.14% in the control. The organic matter in bed soil under 5% coffee sludge biochar treatment was 31.8 ± 5.86%, whereas it was 25.9 ± 6.00% in the control. An increase in the total nitrogen of both field soil and bed soil was observed when the biochar content increased. Chinese cabbage grew better in bed soil with coffee sludge biochar than in field soil because of the optimal pH conditions. Our results support the application of biochar for increased growth of Chinese cabbage, particularly in bed soil.