SOIL TEXTURE AND FERTILIZERS AFFECT NUTRIENT LEACHING

Fertilizer applications are essential for agricultural productivity, but proper management is required to prevent nutrient leaching. This study evaluated potassium and phosphorus movement in soil profiles under two contrasting soil textures and different nutrient sources. Leaching columns were filled with Quartzarenic Neosol (sandy) and Dystrophic Red Latosol (clayey) soils, and six treatments were applied: control (no fertilizers), conventional mineral fertilizers (KCl, MAP, urea), special mineral fertilizers (nitric/ammoniacal base), polymer-coated fertilizers, and two organomineral fertilizers (powdered and granulated cellulose residues with KCl and MAP). Soil texture and fertilizer type significantly influenced nutrient behavior. In Quartzarenic Neosol, high permeability and low cation exchange capacity increased potassium and phosphorus leaching, especially with mineral fertilizers. Organomineral fertilizers reduced nutrient leaching and improved nutrient availability in the upper soil layer. In Dystrophic Red Latosol, the high adsorption capacity of clay minerals and oxides favored nutrient retention. Mineral fertilizers provided quick nutrient release but exhibited greater mobility with improper management. Organomineral fertilizers improved phosphorus retention and potassium stability in the soil profile, offering better agronomic efficiency and reducing nutrient loss in clayey soils. These results emphasize the importance of selecting fertilizers based on soil properties to enhance nutrient use efficiency and mitigate leaching. Management practices such as split applications, controlled-release fertilizers, and irrigation monitoring can further improve nutrient retention. Future research should explore innovative fertilizers and site-specific strategies to promote sustainable nutrient management in diverse soil and climatic conditions.