Construction and Functional Validation of a Cross-Niche Multifunctional Microbial Consortium for Straw-Returning Agricultural Systems

Straw returning, a core practice in conservation tillage, promotes sustainable intensification; however, it faces challenges such as inefficient decomposition, nutrient competition, and pathogen accumulation. To address these limitations, this study aimed to develop a multifunctional microbial consortium specifically designed for straw-incorporating cropping systems. The consortium comprises four <i>Bacillus</i> strains with complementary enzymatic systems, isolated from diverse ecological niches. It exhibited robust lignocellulolytic enzyme production, with manganese peroxidase (7709.33 U/L), laccase (450.65 U/L), endo-β-1,4-glucanase (154.67 U/mL), and filter paper activity (309.18 U/L). The consortium significantly enhanced rice straw degradation by 37.18% and increased nitrogen (N) release by 16.13% compared to the control. Moreover, the consortium exhibited a 67.56% inhibition rate against <i>Magnaporthe oryzae</i> and reduced both the incidence rate and disease index of leaf blast and panicle blast. Field trials revealed increases in the rice grain yield of 9.63% and 6.94% when applied alone and 6.75% and 5.18% when co-applied with straw residues. These findings highlight the multifunctional agricultural potential of the consortium and provide a sustainable strategy to overcome the limitations of straw-incorporating farming systems.