Modulation of microbial populations and biogeochemical cycling by synthetic inoculants and additives in chicken manure composting systems

This study investigated the synergistic effects of synthetic microbial consortia and FeSO4-Ca(H2PO4)2 composite additives on microbial community dynamics and carbon-nitrogen transformation during chicken manure-straw composting. The additives significantly enhanced bacterial diversity and selectively enriched thermophilic phyla, particularly Firmicutes and Actinobacteria. Community assembly mechanisms shifted from stochastic to deterministic processes, indicating strong environmental selection. Network analysis revealed improved microbial network complexity and stability, correlating with accelerated compost maturation. Temperature, pH and moisture were identified as key drivers of microbial succession, with pH exhibiting particularly strong regulatory effects. Functional predictions suggested the additives reduced greenhouse gas emissions while improving nitrogen retention through modulation of key functional genes involved in carbon metabolism and nitrogen cycling. These findings provide mechanistic insights into optimizing composting efficiency through targeted microbial community management.