Biological Mechanisms of Nitrogen and Phosphorus Transformation Enhancement in Straw Composting Mediated by Insects

Insect-mediated composting technology offers a novel approach for straw resource utilization, yet the enhancement of nutrient availability and its underlying mechanisms remain unclear. This study employed rice straw as substrate and selected black soldier fly larvae (BSFL), yellow mealworm larvae (YML), and Protaetia brevitarsis larva (PBL) as subjects. We systematically investigated their enhancement effects on nutrient transformation in straw composting and comprehensively employed high-throughput sequencing, metagenomics, and metabolomics technologies to deeply analyze the underlying biological mechanisms. Results indicate that insect treatments significantly increased the available nitrogen and phosphorus content in the composted products, with BSFL treatment showing the most pronounced effect. Insect treatments markedly altered the bacterial community structure, functional genes involved in nitrogen and phosphorus cycling, and the composition of related metabolites in the composted products.