Enhancing compost maturity and nitrogen content through cocomposting of chicken feather waste with rice husk and vegetable residues

Chicken feather waste is a potential low-cost nitrogen source for fertilizer production. However, due to its recalcitrant biodegradability, low C/N ratio, and high water content, composting chicken feather waste requires amendments. Optimizing the initial substrate composition plays a key role in improving composting performance. This study investigated the effects of varying chicken feather waste proportions, which altered the initial C/N ratio of the composting substrate, on the physicochemical evolution and final product quality of compost mixtures containing rice husk as a bulking agent and readily degradable vegetable residues. The substrates were composted in static compost bins of 20 L for 126 days under ambient conditions (~28°C). Significant differences were observed in physicochemical evolution and compost quality. A higher proportion of chicken feather waste or a lower initial C/N ratio led to increased total nitrogen (TN), extractable NH₄⁺, and SO₄^2‒ concentrations during composting and in the final products. The addition of rice husk and vegetable residue improved the germination index of compost products from chicken feather waste. It was found that more-nutrient-rich compost could be produced by co-composting chicken feather waste with a low C/N ratio.<i>Implications</i>: This study highlights the interrelation of cosubstrates (rice husk, vegetable residue) in the decomposition of chicken feather waste. Nutrient-rich composts were obtained when chicken feather waste was cocomposted with low C/N ratios. Higher proportion of chicken feather waste or lower initial C/N ratio of composting substrate increased total N, extractable NH₄⁺, and SO₄^2- concentrations in compost product. Cocomposting of chicken feather waste with rice husk and vegetable residue enhanced compost maturity and germination index. The findings contribute a scientific basis for promoting the utilization of chicken feather waste to produce N-rich fertilizer.