Unveiling the maize-benefit: Synergistic impacts of organic-inorganic fertilizer cooperation on rhizosphere microorganisms and metabolites

Abstract

Maize, an indispensable staple crop, plays a vital role in ensuring human food security. To shed light on the effects of different fertilizer management modes on maize growth, as well as rhizosphere bacterial populations and metabolites, we employed high-throughput sequencing and non-targeted metabolomics technology. Experimental treatments comprised: CK (no fertilizer), CF (single chemical fertilizer, N-P2O5-K2O), OF30 (30 % organic fertilizer replacement), OF70 (70 % organic fertilizer replacement), and OF100 (100 % organic fertilizer, animal manure and humic acid as raw materials). Compared to the single chemical fertilizer, the dual fertilizer management resulted in a more stable bacterial network and a more complex metabolic system. Notably, under OF70 conditions, the rhizosphere soil exhibited greater prevalence of functional bacteria like Paenibacillus and Pseudoxanthomonas. This stimulation significantly activated biosynthesis processes like unsaturated fatty acids, plant hormone synthesis, and plant secondary metabolite production. Through correlation mining of differential metabolites and differential bacteria, as well as weighted gene co-expression network analysis (WGCNA), we revealed a consistent correlation trend between bacterial population abundance and changes in metabolite content under dual fertilization. The dual fertilizer approach established a more intricate regulatory relationship between plants, bacteria and metabolites, indicative of a more stable rhizosphere environment. Importantly, our findings on the superior growth performance of maize under OF70 conditions, coupled with microecological changes in the rhizosphere (bacteria and metabolites), provide valuable insights for advancing efficient maize cultivation and informing scientifically sound fertilizer management practices. Moreover, these results hold relevance for production considerations in other agricultural crops. However, it is crucial to further explore the generalizability of these findings in field conditions.