Exploring core microbiome diversity in digested versus raw manure impact on rice straw composting

Abstract

Composting as a technique for managing rice straw (RS) provides a pathway to produce compost for agriculture, effectively reducing the greenhouse gas emissions linked to conventional straw disposal methods like burning and reintroducing it into agricultural fields. Existing research often neglects the critical role of selecting appropriate inoculum and understanding their microbiome functions in composting. This oversight significantly impacts the efficiency and quality of the composting process. This study demonstrates the enhanced efficacy of microbial communities derived from anaerobically digested manure (ADS) and raw manure (CD) in the process of composting with rice straw (RS). Mature ADS and CD compost shared 30 OTUs out of 178, with 10 common OTUs in the initial stage. Key microbial taxa increased significantly in mature ADS compared to CD: Acinetobacter (198.15%), Serratia (164.41%), Bacillus (98.94%), Flavobacteria (166.34%), Pseudomonas (167.51%), and Prevotella (172.81%). Additionally, Archaea Haloarcula and Haloferax exhibited higher abundance in mature ADS than in CD by 32.36% and 36.25%, respectively, highlighting the digestion process’s impact on optimizing composting efficiency. ADS exhibited the highest Chao 1 estimate (390.27), Fisher index values (57.52), Shannon index (4.15), and read count (102,162), indicating the highest species richness, even distribution of species, diversity, and genetic information availability. ADS followed closely with values of 372.48, 3.82, and 88,249 for Chao 1, Shannon index, and read count, respectively. This research is significant for its findings concerning the enhanced microbial community within the inoculum, accelerated rates of digestion, shortened initiation period, and the need for further investigation into a variety of materials, including other agricultural residues. © The Author(s), under exclusive licence to Springer Nature B.V. 2024.