Ruhut Marison Purba, Selvie Tumbelaka, Jemmy Najoan, Sofia Wantasen, Adeleyda M. W. Lumingkewas, Melisa Pascawati Todingan
This study aimed to analyze the nutrient content and pH level of liquid organic fertilizer (POC) derived from ketapang (Terminalia catappa L.) leaf waste in Pulisan Village, East Likupang District. This descriptive study compared the use of dried ketapang leaves (DKK) and fresh ketapang leaves (DKB), fermented for 14 days using a combination of the EM4 bioactivator and a local microorganism (MOL) derived from spoiled rice. Laboratory analysis at BSPJI Manado revealed that both treatments yielded an identical nitrogen (N) content of 0.10%. However, the DKK-based POC exhibited higher potassium (K) content (0.36%) and a more acidic pH (3.51) compared to the DKB-based POC (K: 0.18%; pH: 4.38). Conversely, the phosphorus (P) content in the DKB-based POC (0.03%) was higher than that in the DKK-based POC (<0.01%). Physically, the fermentation process altered the solution's color from brick red to black for DKK and to dark brown for DKB. Although the NPK nutrient levels remain below quality standards, this POC still holds potential for sustainably enhancing soil fertility. Keywords: combination, ketapang, leaf, liquid organic fertilizer, spoiled rice