The effect of empty fruit bunch (EFB) biochar and trichoderma biofertilizer (TBF) combination on the growth, yield, and selected nutrient content of chili plant (capsicum annuum L. var kulai) / Nurmaliena Rosli

The use of chemical fertilizers, specifically in chili cultivation, has increased crop yield. However, excessive application and improper management adversely affect the soil quality, ecosystems and human health. In addition to reduce the detrimental effect of chemical fertilizer, the use of organic amendments, such as EFB biochar and TBF, also solves the waste management issues in the oil palm industry. This study analyzed EFB biochar to determine its characteristics and selected nutrient content. Furthermore, the research evaluated the best ratio for the various applied combinations of EFB biochar and TBF to the growth and yield performance of chili plants. Besides, this study also investigated the effect of combined EFB biochar and TBF on soil physico-chemical properties and plant nutrient content of chili plants. This research employed a Randomized Complete Block Design (RCBD) with six treatments and four replications. The treatments include T1= 100% chemical fertilizer, T2= 100% EFB biochar, T3= 100% TBF, T4= 75% EFB + 25% TBF, T5= 50% EFB + 50% TBF, and T6= 25% EFB + 75% TBF. The chili plant was used as an indicator plant and cultivated in Red-yellow Podzolic Soil. The data collected for the characterization of EFB biochar included Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), Field Emission Scanning Electron Microscopy (FESEM), and Nitrogen-PhosphorusPotassium (NPK) content analysis. The growth performance was assessed by collecting data at bi-weekly intervals, which comprised measurements of plant height (cm), stem diameter (cm), chlorophyll content, and plant biomass at harvest. The data acquired for the yield performance included the number of fruits per plant, the weight of fruit per plant (g), and the number of harvests. Soil analysis encompasses Nitrogen (N), Phosphorus (P), Potassium (K), Organic Carbon, Calcium (Ca), Magnesium (Mg), and Cation Exchange Capacity (CEC). Macronutrients and micronutrients such as Nitrogen (N), Phosphorus (P), Potassium (K), Calcium (Ca), Magnesium (Mg), Copper (Cu), Zinc (Zn), Iron (Fe), Manganese (Mn), and Boron (B) were analyzed in both shoot and root tissues of plants. The results revealed that EFB biochar contains high moisture content (65.79%) but low yield (34.03%), which only 6.81kg was successfully converted into biochar from 20kg of raw EFB. Various functional group was found in EFB biochar, such as the hydrogen-bonded hydroxyl group, alkane and alkene. The percent weight of EFB biochar was decreased at a temperature above 300°C. Meanwhile, the FTIR analysis shows high porosity and large surface area, which increase nutrient uptake. This study also revealed the positive impacts of EFB biochar combined with TBF on chili growth and yield compared to the control with the treatment T6 (25% EFB + 75% TBF) demonstrated promising results as the best ratios among other treatments. The study also reflected a positive effect of the combined application on the soil physico-chemical properties and plant nutrient content. These findings provide valuable insights into EFB biochar and TBF application for alternative chili production, reducing reliance on chemical fertilizers. However, further in-depth studies are essential before making recommendations for commercial settings.