london-journal-of-research-in-science-natural-and-formal London Journal of Research In Science: Natural and Formal 2631-8490 2631-8504 JournalsPress 113400 Optimizing Watermelon (Citrullus Lanatus) Production and Profitability on Sandy Ferralsol in Kenge through Integrated Organic and Mineral Fertilization Integrated Organic & NPK Boost Watermelon Yields 25 16 41 52

TThis study evaluated the agronomic performance and economic viability of watermelon (Citrullus lanatus) in Kenge, Kwango Province (DRC), using a 2 × 5 factorial split-plot design with NPK as the main factor and five organic amendments as subplots. Growth and yield traits were measured across 12-plant subplots. Integrated nutrient management significantly improved plant performance, with Neptune’s Harvest™ Fish Fertilizer + NPK producing the highest yield (24.4 t ha⁻¹). Organic amendments enhanced soil physico-chemical properties, increasing NPK retention and nutrient-use efficiency. Marketable yields ranged from 20.3 to 11.6 t ha⁻¹ depending on NPK supplementation. Economic analysis showed strong profitability for combined treatments, with Marginal Rate of Return values of 1.83 for Neptune’s Harvest™ Fish Fertilizer + NPK, 1.76 for biochar + NPK, and 1.70 for Tithonia + NPK, whereas treatments with MRR < 0.5 were not economically viable. Results demonstrate that watermelon production in Kenge is feasible and profitable under integrated nutrient management.

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This study evaluated the agronomic performance and economic viability of watermelon (Citrullus lanatus) in Kenge, Kwango Province (DRC), using a 2 × 5 factorial split-plot design with NPK as the main factor and five organic amendments as subplots. Growth and yield traits were measured across 12-plant subplots. Integrated nutrient management significantly improved plant performance, with Neptune’s Harvest™ Fish Fertilizer + NPK producing the highest yield (24.4 t ha⁻¹). Organic amendments enhanced soil physico-chemical properties, increasing NPK retention and nutrient-use efficiency. Marketable yields ranged from 20.3 to 11.6 t ha⁻¹ depending on NPK supplementation. Economic analysis showed strong profitability for combined treatments, with Marginal Rate of Return values of 1.83 for Neptune’s Harvest™ Fish Fertilizer + NPK, 1.76 for biochar + NPK, and 1.70 for Tithonia + NPK, whereas treatments with MRR < 0.5 were not economically viable. Results demonstrate that watermelon production in Kenge is feasible and profitable under integrated nutrient management.