Sustainable farming practices enhance bacterial diversity and nutrient levels in sorghum rhizosphere soil

Abstract

This research employs metagenomic analysis to explore bacterial diversity in sorghum rhizosphere soil in response to various sustainable farming practices and their impact on soil fertility. The field experiment with cotton-sorghum cropping system was conducted since 2020 and from 3rd cycle sorghum experiment, the soils were collected and subjected to metagenomics and nutrients availability analysis. We evaluated the impact of different farming approaches: Natural Farming (NF), Organic Farming (OF), integrated crop management (ICM), along with a control (No input farming). The results underscores the prevalence of Proteobacteria phylum across all farming practices, while Actinobacteria, Bacteroidetes and Firmicutes showed increased presence due to altered soil management and nutrient availability changes. Genus-level analysis revealed shifts in dominant genera, including Acinetobacter, Sphingomonas, Bacillus, and Candidatus nitrososphaera, across different farming practices. Post-harvest soil analysis indicated varied nutrient levels, with ICM showing enhanced nitrogen, phosphorus, and potassium availability. ICM, utilizing a balanced mix of organic and inorganic fertilizers, promoted sorghum growth, yielding higher plant height and total dry matter compared to OF and NF, which performed similarly. The study emphasizes the efficacy of a balanced approach like ICM for improving crop production and soil nutrient availability. However, all diversified farming practices exhibited high soil biological diversity compared to the control, highlighting the necessity for continuous long-term soil monitoring across different farming practices to stabilize soil microbiomes, ensure nutrient availability, and support sustainable crop production.