The inclusion of legumes in crop rotation has been recognized for its potential to increase soil fertility and microbial functionality. We posited that microbial communities in legume‐based rotation systems exhibit distinct community‐level physiological profiles and higher catabolic activity than those in monocropping systems. To test this hypothesis, we evaluated the respiratory patterns of sorghum rhizosphere microbiomes under legume‐based rotation. Rhizosphere soils were taken from cowpea–sorghum (CS) and soybean–sorghum (SS) rotations, a sorghum‐monocropping system (CN), and bulk soil that is with no crops (BK). With the MicroResp method, we assessed the community‐level physiological profile of the entire soil by using 23 carbon substrates selected on the basis of their importance to soil microorganisms. Our findings revealed significant differences in soil respiration patterns across cropping systems. The average respiration responses were highest in CS (39.49 ± 4.02 c/g/h), followed by SS (23.60 ± 2.11 c/g/h), BK (7.68 ± 0.21 c/g/h), and CN (0.94 ± 0.01 c/g/h). Compared with monocropping and bulk soils, soils from legume‐based rotations (CS and SS) presented greater substrate‐induced respiration rates and greater microbial functional diversity. Principal component analysis revealed distinct clustering of community‐level physiological profiles (CLPPs), with legume‐based rotation soils showing greater utilization of structurally complex carbon substrates. These findings highlight the role of legume‐based rotations in enhancing microbial‐mediated soil processes to improve soil health and carbon cycling, which is beneficial for sustainable farming.
Enagbonma et al. (Thu,) studied this question.