Effects of inorganic and organic treatments on the microbial community of maize rhizosphere by a shotgun metagenomics approach

Abstract

Purpose: The main drivers of biogeochemical cycling of nutrients, plant growth promotion, and disease suppression are microbes. Organic manure increases soil quality and plant productivity; the same is true of inorganic fertilizer. In this study, we explored shotgun metagenomics study to investigate how maize (Zea mays everta) rhizosphere microbial community diversity is shaped following the application of both compost manure and inorganic fertilizer. Methods: We used high throughput next-generation sequencing-metagenomics studies to examine the rhizosphere microbial community of maize plants grown in an organic compost manure (8 tons/ha and 4 tons/ha) and inorganic (120 kg/ha NPK and 60 kg/ha NPK chemical) fertilized soils. An unfertilized soil was used as a control. Results: The taxonomic analysis of the soil revealed that regardless of the fertilization regimes, Proteobacteria and Bacteroidetes are distributed across all the samples, but in varying populations. Higher quantities of organic manure (8 tons/ha) and lower (60 kg/ha) nitrogen fertilizer, as well as the untreated control, supports the selection and enrichment of Proteobacteria and Actinobacteria, while lower quantities of organic compost (4 tons/ha) manure boost the population of Bacteroidetes. Firmicutes, on the other hand, were most abundant in low organic manure (4 tons/ha) and higher inorganic (120 kg/ha) fertilized soil. Fungi were selected and enriched by higher (8 tons/ha) and lower (4 tons/ha) compost manure, while archaea were mostly supported by higher doses of inorganic fertilizers (120 kg/ha) and high compost manure (8 tons/ha) treatments. Conclusion: Therefore, comprehending the effects of compost and chemical fertilizers (NPK-20% nitrogen, 7% phosphorus, 3% potassium) on the community structure, dynamics, and abundance of rhizosphere microbiome will help in the manipulation of soil microbial community to increase microbial diversity in the agroecosystem.