Different Zn loading in Urea–Formaldehyde influences the N controlled release by structure modification

Abstract Nitrogen fertilization has been a critical factor for high crop productivity, where urea is currently the most used N source due to its concentration and affordability. Nevertheless, fast solubilization leads frequent losses lower agronomic efficiency. The modification of structure by condensation with formaldehyde proposed improve nutrient uptake plants reduce environmental losses. Herein we show that co-formulation Zn strongly modifies release (in lab conditions) and, more important, source—ZnSO 4 or ZnO—has role. Urea–formaldehyde (UF) served as matrix zinc sources, chemical characterizations revealed particles influenced length polymeric chain formation. Release tests in an aqueous medium showed UF favors ZnO on other hand, delays ZnSO delivery. Soil incubation fertilizer composites proved slow-release from UF, ideal optimizing nutritional Our results indicated ZnO-UF system beneficial effects both nutrients, i.e., reduces volatilization increases release.