Pengaruh Rasio Ampas Kopi-Kulit Pisang terhadap N total, P2O5, K2O dan pH Pupuk Organik Cair

Spent coffee grounds and banana peel can be used as raw materials for liquid organic fertilizer (LOF), but their proportions may influence its chemical characteristics. This study evaluated four spent coffee grounds-to-banana peel ratios for total N, P₂O₅, K₂O, and pH: P₀ (100:0), P₁ (75:25), P₂ (50:50), and P₃ (25:75), with three independent replicates per treatment. Fermentation was conducted for 14 days in 1-L HDPE reactors using an activator solution. Total N and pH were analyzed using one-way ANOVA and Tukey’s HSD. Because residual normality was not supported, P₂O₅ and K₂O were evaluated using Kruskal–Wallis followed by Dunn’s pairwise test with Holm correction. The ratio did not significantly affect total N. Overall treatment differences were detected for P₂O₅, K₂O, and pH. Dunn–Holm comparisons identified significant differences only between P₀ and P₃ for both P₂O₅ and K₂O. P₃ had the highest descriptive means for P₂O₅ (0.0206%) and K₂O (0.3418%), whereas P₁ had the highest total N (0.0623%). Total N+P₂O₅+K₂O ranged from 0.2354% to 0.4227% (w/v), and pH ranged from 3.34 to 3.74. None of the treatments met the minimum requirements for the two quality parameters assessed.