Evaluation of Developed Novel Hybrid Granular Fertilizers for Sustainable Agriculture in Sri Lanka

抄録

This study developed and evaluated novel hybrid granular fertilizers by blending urea with locally available organic materials using molasses as a binder. Six treatments (T1-T6) were prepared with varying ingredient ratios and granulated using a small concrete mixer. Granule uniformity and size distribution (2.01-4.75 mm and 4.76-8.00 mm) were determined by hand sieving, indicating their suitability for bulk production and industrial application. Water stability was assessed using an aggregate analyzer for over two hours. Nutrient dissolution experiments were conducted to measure the initial release of nitrate and potassium. The results showed low uniformity indices, indicating consistent granule size and production scalability. Molasses alone did not dictate granule formation; a balanced mix of organic materials was essential for this process. Molasses enhanced water stability, but compost (T4) was the most effective for granule stability, outperforming chicken manure. Compost is recommended as a core organic component for stable slow-release granules. One-way ANOVA confirmed a highly significant treatment effect on nutrient release (P < 0.001). T5 and T6 were optimal for crops requiring rapid early season nutrition (leafy vegetables), whereas T4 was suitable for perennials or leaching-prone soils. Biochar-rich T1 and T2 treatments are recommended for soils requiring long-term nutrient cycling. Further optimization is required to tailor the formulations to specific agronomic requirements. These findings contribute to the development of slow-release hybrid fertilizers, thereby supporting sustainable agriculture in Sri Lanka.