Design and Optimization of Soil-Engaging Components for Intelligent Seedbed Preparation in Water-Limited Cropping Systems: A Critical Review

Intelligent seedbed preparation requires more than an optimized soil-engaging component: field condition must be diagnosed, a controllable setting must be adjusted, and the resulting soil zone must be verified. This critical review synthesizes 133 sources across soil mechanics, component design, numerical modeling, field validation, and sensing-control research for water-limited cropping systems. Evidence was compared as bounded within-study contrasts rather than pooled effects because outcome definitions, soils, operating regimes, and validation scales differ. Four recurring conflicts organize the synthesis: fracture versus draft, tilth versus evaporative exposure, residue retention versus blockage, and immediate loosening versus persistence. Reported examples include an increase in the <50-mm aggregate fraction from 76.1% to 88.0%, a study-specific fragmentation index increase from 83.0% to 94.54%, a 43–47% reduction in penetration resistance after geometry-optimized loosening, and rainfall-dependent water-use-efficiency gains of 6.0–11.7% after subsoiling. These values are retained as study-specific anchors, not universal settings. The proposed framework adds value by linking four decision stages—field diagnosis, component design, controlled operation, and post-pass verification—while explicitly separating conventional optimization, monitored operation, and closed-loop intelligent control.