Composted organic manures modulated soil–microbe interactions that enhanced the growth of tobacco by improving rhizospheric microbial structure and soil nutrients

(potential antagonists of soil pathogens) might contribute to the observed enhancement in soil organic matter and available nutrients. This improvement in soil quality led to a balanced nutrient environment, ultimately promoting dry matter accumulation in tobacco plants. These findings offer robust theoretical support for the application of composted organic manures.IMPORTANCEThis study is important because it elucidates the crucial mechanisms by which composted organic manures, specifically through the regulation of the soil-microbe system, promote crop growth. It provides key evidence that the stacking duration is a critical factor, identifying a 20-day (d) composting period for cottonseed meal manure as optimal for delivering comprehensive benefits: (i) Enhanced soil health: significantly increasing soil organic matter and improving nutrient availability. (ii) Improved microbial community: shifting the soil microbial structure to favor beneficial bacteria and suppress pathogens, thereby enhancing metabolic functions related to carbon and nitrogen cycling. (iii) Direct crop promotion: leading to a substantial increase in dry matter accumulation in tobacco plants.