Dhanush Kenchanna is a graduate student in Agricultural Sciences at Texas State University, San Marcos, Texas. His passion lies in fostering sustainable communities through composting and applying compost in horticultural and agricultural production. Currently, he serves as the graduate manager of Bobcat Blend, an on-campus composting program dedicated to diverting food waste towards compost production.

Session Code: 4C

Track: CREF Research

Session Name: Compost Additives and Their Effectiveness: Frass and Biochar

Session Time: Thursday, February 8, 8:30 – 10:00 AM

Presentation Title: Black Soldier Fly Larve (Hermetia illucens) Frass & Sheddingsas a Compost Ingredient

Presentation Description: Nature’s effective decomposers, the Black Soldier Fly (Hermetia illucens), are well-known at their larval stage for their high protein and lipid content. Rearing Black Soldier Fly Larvae (BSFL) produces a byproduct known as frass and larval sheddings, which is waste from the insect diet, dead larvae, and larval excrement. This byproduct is dark in color, safe to handle, and contains 200g/kg of protein and other essential nutrients. As the commercial insect-rearing industry is still emerging in the United States, there is currently not a well-established market for frass. It has been recommended that frass could be composted; however, there is a lack of literature available on frass and larval shreddings as compostable materials, including final compost quality. Accordingly, this study aims to evaluate the frass from BSFL as a viable compost ingredient utilizing additional nitrogen feedstocks, such as livestock manure. Four experimental compost piles (22.85 m3) with different ratios of BSFL frass and sheddings were developed: the first and fourth piles consisted of 25% frass, whereas the second and third piles contained 30% frass. Across piles, wood chips, food waste, and livestock manure varied to determine the best proportion for compost based on prior research. The compost piles were allowed to reach a mesophilic temperature of 38o C; then cured until reaching 32o C. After curing, samples from each pile were collected to analyze pH, macro- and micronutrients, particle size, stability, and maturity. The findings are anticipated to highlight the most effective protocol for developing high-quality compost containing waste from the insect rearing industry.