Effects of Additives on Carbon Conversion and Bacterial Community During Rapid Aerobic Composting

Abstract

To accelerate the aerobic compost decomposition process and reduce the loss of carbon from the pile, we conducted composting experiments with cattle manure and straw as raw materials to assess five treatments: control (CK), magnetized water treatment (M), magnetized water plus biochar treatment (BM), magnetized water plus ferrous sulfate treatment (FM), and magnetized water plus Bacillus megaterium treatment (GM). At the end of composting, compared with CK, the total organic carbon (TOC) content increased significantly by 4.04% (P < 0.05) under FM,respectively. During the high temperature composting stage, where the abundance of frdA, acsA, acsE, and pccA were highest under FM.The abundances of Proteobacteria, Bacteroidota, and Planctomycetota were significantly higher under FM compared with the other treatments, and significant positive correlations were found between these phyla and TOC, C/N, acsA, and pccA.Thus, treatment with ferrous sulfate plus magnetized water effectively enhanced the storage of carbon in compost.

Keywords: Bacterial community, Carbon conversion, Carbon fixation gene, composting, Functional metabolism