This technology uses composted livestock and poultry manure as the primary raw material. Designed specifically for watermelon cultivation in gravelly riverbed soils, the formulation was developed by integrating the nutrient characteristics and mineralization rates of different organic fertilizers with the results from long-term watermelon fertilization trials conducted at our research station. Selected organic materials were incorporated to formulate a blended organic fertilizer tailored to the nutrient requirements of watermelon production. Composted livestock and poultry manure have a relatively slow mineralization rate. By blending it with more rapidly mineralizing organic materials, fertilizer provides a balanced nutrient supply during the different stages of crop growth. In addition, the application of a commercially available slow-release fertilizer as topdressing further improves nutrient availability throughout the growing season. This fertilization strategy reduces fertilizer inputs while maintaining watermelon yield and fruit quality. As extreme weather events have increased cultivation risks in recent years, the gradual and sustained nutrient supply achieved through this approach enhances the stability and resilience of watermelon production.