Abstract:To address the issues of residue accumulation and blockage, significant soil disturbance, low cleanliness of seedbed, and poor seeding quality caused by maize stubble and straw residues during no-tillage wide-row wheat sowing in maize residue-covered fields, a seedbed cleaning method combining passive cutting and subsequent active throwing was proposed. A cutting and spreading combined residue-breaking and residue-preventing device was designed, which utilized longitudinally arranged inclined notched discs and rotating spreading devices to clean seedbed residues and straw. A diversion-type furrow opener was designed to stabilize row spacing and achieve one furrow seeding two rows. The tilt angle and skew angle parameters of the notched discs were determined based on force and kinematic analyses of straw residues during device operation. The straight and inclined rotary blade parameters were designed and calculated based on the sliding-cutting theory. Using the orthogonal rotation combination experimental method, key parameters of the spreading device were optimized through simulation experiments on the established MBD-DEM combined simulation platform, with seedbed cleanliness rate, residue breaking rate, and soil disturbance as indicators. Based on simulation results, regression models for each indicator were established and response surface analysis and multi-objective optimization were conducted. The optimal parameters were determined to be as tilt angle of 20° and rotation speed of 310r/min, resulting in seedbed cleanliness rate of 96.9%, residue bonds breaking rate of 26.9%, and soil disturbance width of 139mm. Wheat seeding experiments in maize residue-covered fields showed that the sowing machine equipped with the cutting and spreading combined anti-breaking and residue-preventing device had good pass ability, with seedbed cleanliness rate of 90.1%, residue-breaking rate of 96.2%, soil disturbance width of 127mm, soil disturbance rate of 6.9%, stable overall operation quality, and uniform wheat emergence after seeding, meeting the agronomic requirements for wide-seedbed seeding of wheat.