Anand Raj Kumar Kullan

With escalating global food demands and environmental concerns from mineral fertilizers, black soldier fly larvae (BSFL, Hermetia illucens) frass is a sustainable organic fertilizer from organic waste. This review synthesizes field applications, agronomic impacts, soil health benefits, comparative efficacy and market prospects. Applied via soil incorporation or topdressing at 60–250 kg·ha–1 N, frass significantly increases crop yields in maize, vegetables (broccoli, lettuce, potato and tomato) and forages, often equaling or surpassing urea or compost. Yield gains from balanced macro- and micronutrients, high organic matter and biostimulant effects, including upregulated defense genes against herbivores and drought resilience via improved photosynthesis. Frass profoundly enhances soil health: chemically, by boosting nutrients and cation exchange capacity; physically, through aggregation and water retention; biologically, via microbial stimulation and enzyme activity. Compared to mineral fertilizers, it offers slow-release N (shorter immobilization, 3–10 times higher mineralization), without leaching risks, and chitin-derived pathogen suppression. Market analyses forecast the overall black soldier fly (BSF) sector to reach 4.12 billion USD by 2032 (32.4% compound annual growth rate), with the biofertilizer (frass) segment as a major contributor driven by circular economy and organic demand. Challenges include feedstock variability, regulatory and standardization gaps. Future research on long-term effects, integrated management and life-cycle assessments will accelerate adoption of BSFL frass as a component of circular, resilient agriculture.

Poultry litter waste management poses a significant global challenge, attributed to its characteristics (odorous, organic, pathogenic, attracting flies). Conventional approaches to managing poultry litter involve composting, biogas generation, or direct field application. Recently, there has been a surge of interest in a novel technology that involves the bioconversion of organic waste utilizing insects (known as entomoremediation), particularly focusing on black soldier fly larvae (BSFL), and has demonstrated successful transformation of various organic waste materials into insect meal and frass (referred to as organic frasstilizer). Black soldier flies have the capacity to consume any organic waste material (ranging from livestock litter, food scraps, fruit and vegetable residues, sewage, sludge, municipal solid waste, carcasses, and defatted seed meal) and convert it into valuable BSFL insect meal (suitable for animal feed) and frass (serving as an organic fertilizer). The bioconversion of poultry litter by black soldier flies offers numerous advantages over traditional methods, notably in terms of reduced land and water requirements, lower emissions, cost-effectiveness, swift processing, and the production of both animal feeds and organic fertilizers. This review focuses on the existing knowledge of BSFL, their potential in bioconverting poultry litter into BSFL meal and frass, and the utilization of BSFL in poultry nutrition, emphasizing the necessity for further innovation to enhance this sustainable circular economy approach.

Pedigree construction using molecular markers in open pollinated bulk seeds is proven to be one of the effective approaches in providing robust information about mating dynamics in the seed orchard. In addition, pedigree construction combined with phenotypic pre-selection of the progeny trees will eventually reduce the cost of genotyping and time. In the present study, we used highly informative microsatellite markers to construct half-sib and full-sib families from phenotypically pre-selected individuals for growth in an open pollinated hybridization seed orchard consisting of E. camalulensis and E. urophylla . All the progenies were assigned with their respective female parents, while 84 % of the progenies were assigned with their candidate male parents. Both single locus ( t̂ _s ) and multi- locus ( t̂ _m ) outcrossing estimates revealed high level of outcrossing rate in the seed orchard. Intra-specific combinations in the progenies were found to be high compared to inter-specific hybrids. Variance components estimates using half-sib and full-sib based model revealed high heritability (h2) for diameter at breast height (DBH) and height in the half sib model. We also found significant correlation between the breeding values estimated for parents and progenies in the half-sib and full- sib model using Best Linear Unbiased Prediction (BLUP) method. Present study demonstrates that molecular marker based pedigree construction combined with phenotypic pre-selection from open pollinated bulk seeds is an effective approach for identifying superior parents and studying mating dynamics in the seed orchard. In addition, breeding value estimates could eventually increase the efficiency and accuracy of forward, backward, and mixed selection models.