Characterization and Utilization of Zeolite for NPK Slow Release Fertilizer (RESEARCH NOTE)

Based on various characteristics of zeolite, its utilization in the manufacture of fertilizers with slow-release properties is possible. The objectives of this study are to characterize and utilized nitrogen, phosphorus and potassium (NPK) slow release fertilizer by using natural zeolite in Indonesia. In this research, zeolite was utilized as a mixture of Slow Release Fertilizer (SRF). Effect of zeolite addition to single/multi-nutrients NPK fertilizer, compacting process, and applied medium on the average rate of fertilizer solubility was investigated. Fertilizer compaction results of NPK, NPK + zeolite, and (N-P-K) + zeolite were characterized by SEM EDS to examine the surface morphology and chemical composition of the fertilizer samples. Nutrients content in soil, domestic water, and demineralized water medium were analyzed by AAS. Base on the experimental results, it was found that addition of zeolite in the single (N-P-K) or multi-nutrients (NPK) fertilizer reduced the average rate of solubility of nutrients in the leaching medium. The results of this study showed that (N-P-K) + zeolite fertilizer has the lowest average rate of solubility than the other samples, it was proved by its average rate of solubility in soil, domestic water, and demineralized water medium, i.e. 9.63 ppm/h, 23.97 ppm/h, and 14.68 ppm/h, respectively.