Effects of the Optimal Ratio of Hanwoo Manure and Coffee Marc on the Biodegradation Capability of Black Soldier Fly ( Hermetia illucens ) Larvae, Am

ABSTRACT

Hanwoo manure has been a nutrient source for agriculture for centuries. In addition, coffee byproducts have been used as ingredients in animal feed. However, improper disposal and management of these materials have led to environmental issues such as air pollution and toxicity. We aimed to assess the effects of an optimal ratio of hanwoo manure to coffee marc‐only hanwoo manure and a 1:1 or 3:1 ratio of hanwoo manure to coffee marc on the decomposition capability of black soldier fly ( Hermetia illucens ) larvae, as well as NH ₃ and total nitrogen levels. Regarding the biodegradation capability of black soldier fly larvae, there were remarkable effects when using a mixture of hanwoo manure and coffee marc in a 3:1 ratio compared with the other groups. During the composting process, a mixture of hanwoo manure and coffee marc by black soldier fly larvae resulted in a reduction in NH ₃ by 90.9%–92.7% in a 3:1 ratio and by 93.8%–97.8% in a 1:1 ratio. Simultaneously, there was an increase in total nitrogen content at a 3:1 ratio of hanwoo manure to coffee marc by black soldier fly larvae. These two changes are related to a decrease in pH levels. In conclusion, these findings indicate that using black soldier fly larvae at a 3:1 ratio of hanwoo manure to coffee marc is effective in improving biodegradation capability and having the potential to increase total nitrogen levels by lowering NH ₃ , thereby offering an ideal alternative with a reduced environmental impact.