Production of Potassium-Rich Biofertilizer from Composted Banana Peels and Watermelon Rinds

banana peels and watermelon rinds, focusing on the mineral content and its impact on plant growth. The process involved characterizing raw materials, producing biofertilizer, analyzing mineral concentrations (potassium, nitrogen and phosphorus), and evaluating its quality through Spiny Amaranth seed growth. A compost bin with three compartments was designed, testing three composting ratios of banana peels to watermelon rinds (2:1, 1:2 and 1:1). Composting was monitored on moisture content, pH, organic matter, and temperature for 37 days. The 1:1 ratio had the lowest temperature (33.45°C) and highest pH (7.08), while the 2:1 ratio had the highest moisture content (36.47%). The 1:2 ratio, with 5.87% potassium, produced the best Spiny Amaranth growth. The potassium-rich banana peels and watermelon rinds likely provided essential nutrients for water uptake, enzyme activation, and stress tolerance. The compost also contained 1.63% and 0.75% phosphorus, promoting growth and root development. This potassium-rich biofertilizer, compared to commercial NPK fertilizers, shows potential as a potassium-mobilizing fertilizer, though additional phosphorus and nitrogen are needed for optimal growth. This study shows that organic waste - banana peels and watermelon rinds can produce potassium-rich biofertilizers, supporting sustainable agriculture and reducing synthetic fertilizer reliance.