Frass Forward: Transforming Waste into Sustainable Feed and Fertilizer

Commodities

Practices

The global insect protein market is projected to reach $16.4billion by 2032, presenting a significant opportunity for small and minority farmers in the SSARE region. Insect farming offers a low-cost, scalable solution for producing nutrient-rich insect-based soil amendments and feed inputs, supporting circular and sustainable farming systems. Insect frass, a byproduct of insect farming, aligns with circular economic principles and offers promises for improving soil health and crop productivity. Frass contains valuable nutrients such as nitrogen, phosphorus, and organic matter, along with beneficial bacteria and chitin, which may support gut health and immunity in poultry. Despite its promise, broader adoption is limited by concerns about pathogen contamination, food safety, and absence of standardized treatment methods and application guidelines. This project aims to evaluate black soldier fly larvae frass as a safe and effective soil amendment and poultry feed ingredient. Building on foundational research demonstrating frass's agronomic and nutritional benefits-such as improved yield, nitrogen use efficiency, and gut health support in poultry, this project will evaluate scalable treatments (heat, phytochemical extracts, and composting) to reduce pathogens while preserving/enhancing the nutrient quality of frass for both soil and feed use. Trials will assess the impact of frass on pathogens, soil health, corn yield, and poultry performance in organic systems. By addressing key regulatory, safety, and agronomic knowledge gaps, this research will help unlock the full potential of insect frass, promoting sustainable farming, reducing dependence on synthetic fertilizers and conventional feed inputs, and contribute to the growth of a resilient circular bioeconomy.

The ultimate goal of this project is to enhance the sustainability of agricultural systems in the Southeastern U.S. by integrating insect farming with the use of insect frass as a safe and effective poultry feed ingredient and organic fertilizer. This circular approach transforms agrifood waste into valuable protein for animal feed and nutrient-rich fertilizer for crops, contributing to food security, economic opportunity, and environmental resilience for underserved communities across the SSARE region.

To ensure the safe use of insect frass in both crop production and animal feed, the University of Arkansas and the USDA-ARS will collaborate on research, education, and technology transfer. This partnership will focus on evaluating the microbial food safety risks associated with frass and developing effective mitigation strategies to reduce potential contamination in both poultry feed and agricultural applications.

Specific project objectives include:

1. Assess the levels of key foodborne pathogens and indicator organisms in insect frass used as poultry feed by quantifying baseline levels of key foodborne pathogens and indicator organisms (Salmonella, E. coli, Campylobacter, Listeria, Total Coliforms, yeast and mold) in frass for use in animal feed and as a soil amendment.

2. Develop and evaluate scalable mitigation strategies to reduce foodborne pathogens in insect frass for use in poultry feed, including:

• Thermal treatment using controlled heat exposure.
• Composting to simulate practical on-farm waste management approaches.
• Phytochemical applications incorporating naturally derived antimicrobial agents.

Each strategy will be assessed individually for its effectiveness in reducing Salmonella, E. coli, Campylobacter, and Enterobacteriaceae to levels compliant with USDA National Organic Program standards. The feasibility, cost-effectiveness, impact on nutrient composition, and suitability for use in poultry feed will be evaluated, with special consideration for small- and medium-scale producers.

3. Characterize the Physicochemical Properties of Insect Frass Before and After Treatment and Determine the Effects of Treated Frass: This project will evaluate thermal, composting, and phytochemical treatments of insect frass, analyzing nutrient composition (total nitrogen, phosphorus, potassium), pH, organic matter content, C:N ratio, and other key parameters influencing its effectiveness as a fertilizer and poultry feed ingredient. Efficacy will be assessed through both poultry feed trials-measuring feed intake, growth performance, feed conversion ratios, and overall animal health-and field studies using organic corn (Zea mays) to evaluate impacts on soil microbial activity, nutrient release dynamics, crop health, and soil health indicators under organic farming conditions.

Ultimately, treated insect frass offers a low-cost, scalable strategy for enhancing soil health, crop productivity, and poultry nutrition, furthering the transition towards environmentally responsible and economically viable agricultural systems.