Background Sustainable agricultural practices are crucial for enhancing soil health and crop productivity in the face of increasing climate variability. Although conservation tillage and crop residue management are known to enhance resource use efficiency and carbon sequestration, their combined effects on soil carbon dynamics and yield in cereal-legume intercropping systems, especially in semiarid regions, remain underexplored.Aim This study examines the synergistic effect of combining reduced tillage (RT) paired with residue return on soil organic carbon sequestration and crop productivity in a maize-soybean intercropping system.Method A field experiment was conducted using different tillage practices, such as conventional tillage (CT), minimum tillage (MT), RT, and residue management approaches (with and without residue return) in a maize-soybean intercropping setup over 2 years.Results RT combined with residue return in sole soybean cultivation significantly enhanced soil nutrient availability, recording the highest concentrations of nitrate (8.65 mg kg-1), phosphorus (6.7 mg kg-1), and potassium (85 mg kg-1), outperforming CT. RT also improved total organic carbon (TOC) content (6.1 g kg-1) and carbon sequestration rate (2.42 Mg ha-1 year-1), compared to lower values under CT with sole maize (5.3 g kg-1 and 2.00 Mg ha-1 year-1), emphasizing the carbon storage potential of legume-based systems. In terms of productivity, both CT and RT improved grain yield and land equivalent ratio (LER: 1.43 and 1.38, respectively), whereas MT consistently showed the lowest performance (LER: 1.08-1.09). However, the outcomes are site-specific to semiarid conditions, and their broader applicability may depend on factors such as soil type, management history, and environmental variability across different regions.Conclusion These findings demonstrate that combining climate-smart tillage with residue return is an effective strategy to enhance both environmental sustainability and agricultural productivity in cereal-legume systems under semiarid conditions.