Utami M, Akim JAS, Ifah AA, Syibyan FL. Encapsulation of NPK in snake fruit peel biochar (Salacca edulis) and activated natural zeolite as a slow-release fertilizer for water spinach (Ipomoea reptans Poir). Sains Tanah J. Soil Sci. Agroclimatology. 2026;23(1):82-91. doi:10.20961/stjssa.v23i1.110863