Enhancing Chili Growth and Yield: The Synergistic Effects of Biochar and Inorganic Fertilizers on Soil Properties and Nutrient Use Efficiency

A pot experiment was conducted during the Kharif 1 season at Hajee Mohammad Danesh Science and Technology University, Dinajpur, to explore the synergistic effects of biochar and inorganic fertilizers on the growth, yield, soil properties, and nutrient use efficiency of chili (Capsicumannum L.). The study was structured in a Randomized Complete Block Design (RCBD) with five treatments: T0 = Control (no fertilizer), T1 = 100% recommended doses of NPK, T2 = 100% biochar (10t ha-1), T3 = 75% biochar + 25% NPK, T4 = 50% biochar + 50% NPK, and T5 = 25% biochar + 75% NPK, replicated four times. Results indicated that combined treatments of biochar and NPK fertilizers significantly enhanced chili growth and yield attributes compared to individual applications. Among the treatments, T4 (50% biochar + 50% NPK) recorded the highest values for most growth parameters, including plant height (38.6 cm), root length (10.50 cm), and number of leaves (78 plant-1), as well as yield attributes like the number of fruits per plant (119), individual fruit weight (2.1 g), and total fruit weight (249.5 g). This treatment also improved soil properties, particularly pH, organic matter content, and available phosphorus, while enhancing nutrient use efficiency having strongly positive correlation. The findings suggest that a 50:50 combination of biochar and NPK fertilizers optimizes chili production by reducing chemical fertilizers with improved soil health through the enhancement of efficient nutrient uses and crop productivity, making it a promising strategy for sustainable agriculture.