Opportunities and challenges in upcycling agri-food byproducts to generate insect manure (frass): A literature review

• Published in: Waste management (Elmsford) 2024-03, Vol.176, p.169-191
• Main Authors: Hénault-Ethier, Louise, Quinche, Mélissa, Reid, Béatrice, Hotte, Noémie, Fortin, Alexis, Normandin, Étienne, de La Rochelle Renaud, Guillaume, Rasooli Zadeh, Aliyeh, Deschamps, Marie-Hélène, Vandenberg, Grant
• Format: Article
• Language: English
• Subjects: Animals; Canada; Crops, Agricultural; Edible insects; Fertilizers - analysis; Frass; Humans; Insect Manure; Insecta; Manure; Organic Fertilizer; Refuse Disposal; Soil; Soil Amendment
• ISSN: 0956-053X; 1879-2456
• DOI: 10.1016/j.wasman.2023.12.033

•Entotechnologies involve insects to upcycle organic waste.•Frass is an animal manure produced by insects.•2–4 tonnes of frass are co-generated for each tonne of edible insect produced.•Frass has fertilizing, plant protection and soil health promoting properties.•Frass regulation is developing in Canada, USA and Europe. A range of issues related to sustainability in the agrifood industry have spurred interest in mass production of insects as human food and animal feed alternatives. This rapidly evolving sector addresses several challenges, including the management of food waste or agrifood by-products and the production of alternative animal proteins demonstrating low environmental impacts that improve sector circularity. The mass production of insects on agrifood processing wastes or by-products represents an opportunity to address these challenges. While the production of insects offers prospects for sustainable protein production, a major side stream is the production of frass or larval excrement including uneaten feed and chitin-rich exuviae (derived from multiple larval moults). The production of each tonne of edible insects generates 2 to 4 tonnes of frass with an interesting potential in agriculture versus traditional organic amendments (compost, manure, biochar). This review aims to demonstrate the characteristics of frass, its common harvest and conditioning methods, its optimal application rates for planting crops, the mechanisms by which it can protect plants against biotic and abiotic stresses and demystify the risks and potential associated with its application in agriculture. The characteristics of frass are compared with those of conventional fertilizers or other. This report also compiles the Canadian, US and European regulatory frameworks as a novel plant fertilizer and aims to pave the way for future research necessary for its valorization in plant production.