Sugarcane-peanut intercropping promotes crop health by recruiting beneficial bacteria, enhancing soil and crop productivity

Sugarcane–peanut intercropping is widely practiced to improve agricultural sustainability, yet how this farming system impacts sugarcane crop health and boosts soil and crop productivity remains unclear. To address this knowledge gap, we investigated how such a farming system influences soil physicochemical properties, sugarcane growth, disease incidence, and bacterial communities across different growth stages and locations. A randomized block design field trial with sugarcane monoculture and wide-row sugarcane–peanut intercropping was established across two locations. Bacterial communities were characterized in rhizosphere and bulk soils using 16S high-throughput sequencing. Sugarcane-peanut intercropping significantly enhanced land-use efficiency (Land Equivalent Ratio (LER) increased from 1.00 to 1.42 at Site A and to 1.21 at Site B). Moreover, stem diameter increased significantly in the intercropping plots by 8.43% and 9.51% compared with monoculture across Site A and Site B, respectively. Single-stem weight increased significantly under the sugarcane–peanut intercropping at Site B compared to Site A. The number of effective stems per hectare decreased significantly by 14.99% and 30.36% in the intercropping plots at Site B. Alkali-hydrolyzable nitrogen, available phosphorus, and exchangeable potassium were significantly higher in intercropping fields compared with monoculture rhizosphere and bulk soils at both sites during the sugarcane maturity stage. Notably, key plant growth- and stress-regulating bacterial (PGSRB), including Stenotrophomonas, enriched significantly in the intercropping rhizosphere soil at Site A, while Burkholderia-Caballeronia-Paraburkholderia, Azospirillum, and Rhizobiaceae exhibited a similar phenomenon in the intercropping bulk soil during the elongation stage. Similarly, Burkholderia-Caballeronia-Paraburkholderia , Mesorhizobium, Bradyrhizobium, and Bacillus were enriched significantly in the intercropping rhizosphere and bulk soils during the maturity stage. The recruitment and proliferation of these PGSRB were associated with the suppression of red stripe disease across both sites. Taken together, these findings suggest that this farming system is an eco-friendly approach that supports crop health and boosts soil and crop productivity. • Sugarcane-peanut intercropping significantly enhanced Land Equivalent Ratio (LER) • Intercropping improved stem diameter and single-stem weight across sites. • Sugarcane-peanut intercropping increased key soil physicochemical properties. • Intercropping enriched key bacteria including Azospirillum and Burkholderia. • Bacteria enrichment was associated with reduced sugarcane red stripe disease.