Long term integrated nutrient management promotes soil bacterial diversity and beneficial community structure

Abstract

Meeting the needs of a world population projected to exceed 9 billion by 2050 requires a 70–100% increase in agricultural output, posing a serious threat to sustainable agricultural practices. The agricultural system, reliant on the harsh application of chemical fertilizers and pesticides, continues to undermine environmental sustainability and overall food quality. This study investigates the impact of nutrient management practices, such as FYM, straw, green manure, and NPK fertilizers, on the soil bacterial community structure through 16 S rRNA sequencing. Key findings showed that certain bacterial phyla, such as Proteobacteria, Actinobacteria, and Firmicutes, have the highest relative abundance and are involved in nutrient cycling, organic matter decomposition, and plant growth-promoting activities. Taxonomically distinct distributions were associated with each sample as well. Proteobacteria and Firmicutes predominated in control, NPK and NPK with Green Manure samples, while a change in phyla dominance was observed in NPK with FYM and NPK with wheat straw samples. Analysis at the genus level showed high proportions of Pseudomonas and Bacillus in the control and NPK samples, and of Sphingomonas in the NPK with FYM samples. Additional analyses on the diversity provided metrics of hypothesis-testing variation across samples, showing the most significant difference at NPK with FYM versus the control sample, which had the lowest metrics. The applied combinations of organic amendments with NPK fertilizer had greater effects on population and index metrics of microbial heterogeneity, suggesting beneficial impacts on the diversity of soil environments.