Opportunities and Challenges for the Use of Insect Frass in Circular Plant-Soil Systems

Global agricultural systems are under increasing pressure to produce more food while reducing environmental impacts, including soil degradation, nutrient depletion, greenhouse gas emissions, and waste generation. At the same time, nearly one-third of all food produced globally is lost or wasted, highlighting major inefficiencies in current food systems and the need for circular approaches. In this context, insect farming has emerged as a promising strategy for converting organic waste into valuable products such as protein for animal feed and nutrient-rich by-products such as frass. Frass – the mixture of insect excreta, exoskeletons, and residual feed – is gaining attention as a potential organic amendment due to its nutrient content and beneficial microorganisms. However, its composition, agronomic performance, and environmental impacts remain highly variable and not yet fully understood. This Research Topic aims to address these knowledge gaps and advance the scientific basis for integrating insect frass into sustainable and circular plant-soil systems.The insect farming industry is increasingly interested in using frass as a key by-product to generate additional revenue streams, while row crop and pasture farmers can benefit from more environmentally friendly, regionally available fertilizer alternatives. Insect frass has the potential to bridge these needs by contributing to more sustainable and circular agricultural systems. However, realizing this potential requires further information on its composition, agronomic performance, and environmental impacts across different cropping systems, as well as on frass production, market development, and economic feasibility. Recent studies have demonstrated promising effects of frass on soil organic matter and fertility, soil microbial activity, plant nutrition, nutrient use efficiency and tolerance to insect pests, with inconsistent results on crop production across environments and management practices. Integrated research is needed to address these knowledge gaps and advance frass as another frontier in plant-soil systems. This Research Topic aims to consolidate current knowledge and promote multidisciplinary studies that generate robust evidence to support the safe, effective, and scalable use of insect frass in sustainable agriculture.This Research Topic aims to advance the understanding of the plant-soil interactions associated with insect frass and promote its widespread utilization by showcasing research that demonstrates its transition from an emerging concept to a reality in agricultural systems. We invite submissions on topics including:• Frass characterization and composition• Effects of feed source and pre-treatments on frass quality• Frass as livestock feed• Applications in urban and controlled-environment agriculture• Soil health and nutrient cycling• Greenhouse gas emissions, air quality, and water quality• Frass and plant growth promoting soil organisms• Crop productivity and plant nutrition• Water and nutrient use efficiency• Impacts on insect pests and natural enemies• Economic feasibility and scalability of frass• Life cycle assessment• Environmental sustainability• Other topics that advance the adoption of insect frass in sustainable agricultural intensification and circular bioeconomy systemsThe Research Topic will accept original research articles, research reports, and opinion papers. Perspective articles are invited to explore future directions for the insect frass industry, including technological innovation, regulatory frameworks, and market development. Collectively, these contributions aim to support the scientific and practical advancement of frass as a key component of sustainable and circular agriculture. Topic editors: Helen Amorim, Diogo N. Cardoso, Christos Athanassiou Source: https://www.frontiersin.org/research-topics/83934/opportunities-and-challenges-for-the-use-of-insect-frass-in-circular-plant-soil-systems