Valorization of traditional herbal drink production waste into aerated compost tea: NPK content for sustainable organic fertilizer development

Abstract

This study explored the valorization potential of traditional herbal drink production waste as a raw material for aerated compost tea within a circular bioeconomy approach. Traditional herbal drink production generates organic waste from rhizomes, leaves, seeds, fruits, rice sediment, and other herbal materials that are commonly discarded without further utilization. In this study, mature compost derived from traditional herbal drink waste was processed into aerated compost tea under different aeration durations (24 h, 48 h, and 72 h). The experiment used a completely randomized design with three replications for each treatment. Nitrogen (N), phosphorus (P), and potassium (K) contents were analyzed as nutrient-quality indicators of the liquid organic fertilizer candidate. The results showed numerical variations in N, P, and K contents among treatments. The 48-h aeration treatment produced the highest mean nutrient values, namely 3.44 ± 0.51% N, 3.78 ± 0.50% P, and 2.31 ± 0.20% K. However, one-way ANOVA indicated that aeration duration did not significantly affect N, P, or K contents at the 5% significance level. Therefore, the observed differences should be interpreted as descriptive trends rather than statistically confirmed treatment effects. These findings demonstrate that traditional herbal drink production waste has potential to be valorized into nutrient-containing aerated compost tea, supporting organic waste recycling and sustainable organic fertilizer development.