The Quality of Organic Fertilizer from Chicken Manure Fortified with Agricultural Waste Using a Rotary Drum System

Purpose: Organic fertilizer from chicken manure has the ability to improve soil structure, enhance the soil's capacity to retain water and air, and stimulate beneficial microbial activity within the soil. The objective of this research is to improve the quality of organic fertilizer derived from chicken manure by adding organic waste through composting using a rotary drum system. Method: follows an experimental approach using a Completely Randomized Design (CRD). The treatments applied were as follows: P0=100% layer chicken manure; P1= 50%-layer chicken manure: 50% coffee husk waste. P2= 50%-layer chicken manure: 50% banana peel waste. P3 = 50%-layer chicken manure: 50% rice husk ash. The compost quality parameters measured included nitrogen (N), phosphorus (P), potassium (K), organic carbon (C-organic), moisture content, and the C/N ratio, Result: The research findings indicated significant differences (P<0.05) in nitrogen content, potassium content, carbon content, C/N ratio, and moisture content of the organic fertilizer with different types of agricultural waste. However, phosphorus content did not show significant differences with the addition of any agricultural waste. Conclusion The addition of 50% coffee husk to chicken manure (P1) produced the best compost quality, with the highest nitrogen (2.47%) and organic carbon (32.19%), a C/N ratio of 13.03 within the SNI standard, and a stable pH of 7.0. While phosphorus remained stable, all treatments met the SNI requirements, confirming P1 as the most effective formulation for high-quality organic fertilizer. Highlights · The study evaluated the effect of fortifying chicken manure with agricultural wastes (coffee husk, banana peel, and rice husk ash) on compost quality using a rotary drum composter. · The rotary drum system enhanced aeration and uniform mixing, accelerating composting and improving nutrient stability. · The combination of 50% chicken manure and 50% coffee husk (P1) produced the best results with N = 2.47%, C-organic = 32.19%, and C/N ratio = 13.03, meeting SNI 19-7030-2004 standards. · Coffee husk addition improved nitrogen, potassium, and carbon content while reducing moisture content to 26.30%. · All formulations met SNI quality requirements, but only P1 achieved optimal compost maturity, neutral pH (7.0), and blackish-brown color indicating stable humus formation. · The findings confirm that fortification with coffee husk in rotary drum composting is an effective method for producing high-quality organic fertilizer from poultry waste.