Straw management significantly influences soil microbial dynamics, shaping biodiversity and resistance in agroecosystems. This study investigated how distinct straw management practices affect bacterial communities and their ecological interactions in bulk soil and the sugarcane rhizosphere. The study was conducted in an Oxisol using a split-plot design with two straw management treatments (burnt and unburnt) and two soil compartments (bulk soil and rhizosphere). Bacterial communities were characterized using 16S rRNA gene sequencing, followed by analyses of diversity, co-occurrence networks, and niche occupancy. The rhizosphere consistently exhibited higher bacterial richness and diversity, regardless of straw management. Burnt straw reduced the relative abundance of Actinobacteriota (~52%) and Firmicutes (~53%) but increased Proteobacteria (~65%) in bulk soil, whereas the rhizosphere bacterial community remained stable. Network analysis revealed higher connectivity and modularity in the rhizosphere, while burnt straw increased negative correlations and reduced microbial complexity in bulk soil. Niche occupancy analysis showed a higher proportion of specialist taxa in the rhizosphere, particularly under burnt straw. Overall, the sugarcane rhizosphere exhibited high microbial resistance to straw burning. These findings highlight the importance of sustainable straw management for preserving soil biodiversity and maintaining ecological stability in tropical cropping systems.

Soil organic carbon (SOC) reflects soil quality and affects ecosystem productivity and the capacity for carbon sequestration. Grazing regimes modulate the status of SOC in grasslands, but their impacts on SOC distribution among soil aggregates are not entirely clear. In this study, the effects of grazing with different intensities and no-grazing with varied enclosure durations were investigated. Increasing grazing intensity enhanced the proportion of 150‒53 μm aggregates, while reducing larger aggregates. After 5 years of enclosure, the distribution of soil aggregates in heavily degraded grassland recovered to resemble that in light-grazed grassland. Heavy grazing decreased SOC concentration in the 10–20 cm layer, and SOC concentration in different aggregate sizes decreased with increasing grazing intensity. Differences in SOC stocks among management measures were mainly reflected in the 10–20 cm soil layer, with heavy grazing significantly reducing SOC stocks. SOC stocks were lowest in 2000–250 μm and 250–150 μm aggregates and highest in <20 μm aggregates. Moderate grazing enhanced SOC stocks in <20 μm aggregates. In the 10–20 cm soil layer, 10 years of enclosure significantly decreased SOC stocks in 2000–250 μm, 250–150 μm and <20 μm aggregates compared to 5 years of enclosure. It indicated that grazing regimes affected grassland carbon sequestration and its distribution in soil aggregates, and moderate grazing had a better positive effect on carbon sequestration. This study provides novel insights into the patterns underlying changes in soil organic carbon from soil aggregates perspective.