Effects of Cocoa Pod Husk Biochar on Growth of Cocoa Seedlings in Southeast Sulawesi-Indonesia
Background and Objective: High quality cocoa seedlings can be produced by improving soil fertility of the plant growing media through application of biochar during the nursery growing period. This study aimed to evaluate the effect of cocoa pod husk (CPH) biochar on soil temperature, soil moisture and growth attributes of cocoa seedlings. Materials and Methods: The experiment was conducted in the glasshouse of Agricultural Faculty, Halu Oleo University, Kendari, Southeast Sulawesi, Indonesia. The experimental design was a randomized block design with seven levels of cocoa pod husk (CPH) biochar (i.e., without biochar (control), 3 g of CPH biochar kg-1 soil, 6 g of CPH biochar kg-1 soil, 9 g of CPH biochar kg-1 soil, 12 g of CPH biochar kg-1 soil, 15 g of CPH biochar kg-1 soil and 18 g of CPH biochar kg-1 soil in 3 replications. Data were analyzed by using two way analysis of variance (ANOVA) followed by Duncan’s multiple range test with an error rate of 5% (p<0.05). Results: The CPH biochar significantly increased soil temperature, soil moisture, soil fertility and cocoa seedling growth. The application of CPH biochar kgG1 increased soil pH, soil-C, P and CEC (cation exchange capacity). Cocoa seedling growth was significantly improved by CPH biochar and a rate of 9 g CPH biochar kg-1 soil showed the best results in cocoa seedlings in terms of increased seedling height, number of leaves, leaf area and shoot dry weight by 20.99, 26.62, 75.63 and 78.36%, respectively, as compared to control. Conclusion: Therefore, CPH biochar has the potential to improve soil temperature, soil moisture, soil pH, soil organic- C, P, CEC and cocoa seedling growth, however, the amount of CPH biochar material applied should be considered.