A Review of Mechanized Harvesting, Threshing, and Cleaning Devices for Pulses

Against the backdrop of intelligent and precision agriculture, mechanized harvesting of pulses is crucial for improving productivity and addressing the challenges posed by the changing agricultural workforce structure. However, the biological characteristics of pulses—such as susceptibility to grain breakage, pod shattering, and asynchronous maturity—impose far more stringent demands on threshing and cleaning performance than those for cereal crops. Existing grain combines, when directly applied to pulses, commonly cause high grain breakage during threshing, high cleaning losses, and poor adaptability. This paper systematically reviews the current status and development trends of threshing and cleaning technologies in mechanized pulse harvesting. The core challenges are analyzed from three perspectives: crop biology, technical bottlenecks, and external operational factors. Research progress and breakthrough pathways in low-damage threshing are reviewed in terms of physical and biomechanical properties, flexible threshing elements, multi-stage cylinder structures, multi-field coupled simulation, intelligent control, and energy consumption analysis. Key achievements and breakthrough pathways in high-efficiency cleaning are summarized from aspects of airflow–screen coupling optimization, screening system innovation, numerical simulation, and intelligent detection and control. Based on typical machine models, the structural characteristics and operational applicability of general-purpose and specialized combine harvesters are compared and analyzed. Finally, future development directions are discussed from four perspectives: multifunctionality and generalization, simplification and adaptability, intelligence and precision, and greening and energy efficiency. This paper aims to provide a systematic theoretical reference and technical support for the development, improvement, and industrial application of low-damage, high-efficiency pulse harvesting equipment.