Synergistic improvement of humus formation in compost residue by fenton-like and effective microorganism composite agents

Improving the humification of compost through a synergistic approach of biotic and abiotic methods is of great significance. This study employed a composite reagent, comprising Fenton-like agents and effective microorganisms (EM) to improve humification. This composite reagent increased humic-acid production by 37.44 %, reaching 39.82 g kg−1, surpassing the control group. The composite reagent synergistically promoted micromolecular fulvic acid and large humic acid production. Collaborative mechanism suggests that Fenton-like agents contributed to bulk residue decomposition and stimulated the evolution of microbial communities, whereas EMs promoted highly aromatic substance synthesis and adjusted the microbial community structure. Sequencing analysis indicates the Fenton-like agent initiated compost decomposition by Firmicutes, and EM reduced the abundance of Virgibacillus, Lentibacillus, and Alcanivorax. Applied as an organic fertilizer in Brassica chinensis L. plantations, the composite reagent considerably improved growth and photosynthetic pigment content. This composite reagent with biotic and abiotic components provides a learnable method for promoting humification.