Justification of Parameters of a Prismatic Device for Fertiliser Distribution Across the Width of the Sub-Blade Area of a Flat-Cutting Working Body

Abstract Subsurface application of mineral fertilisers is an effective agricultural technique that improves both the quantity and quality of cultivated crops. To ensure uniform distribution of granular mineral fertilisers across the width of a tillage working body with a working width of 50 cm or more, spreading devices shaped like triangular prisms with curved working faces are installed in the sub-blade area. For uniform fertiliser distribution across the entire width of the sub-blade area, fertiliser particles must follow variable trajectories that evenly intersect the sub-blade area. Our hypothesis is that this can be achieved by modifying the spreading device, cutting off a portion so that the curved edges of its working faces have different lengths. The aim of this study is to determine the optimal angle of inclination of the cutting plane relative to the prismatic spreader‘s working faces. Our research methods include physical and mathematical modelling, as well as abstraction, analysis, and synthesis. We also conducted experimental studies in accordance with current regulatory documentation. The optimal angle of inclination of the spreader‘s cutting plane was determined to be 80°. We manufactured several spreader prototypes and conducted experimental studies to evaluate how the cutting plane‘s angle of inclination affects the unevenness of fertiliser distribution. The minimum unevenness, ranging from 24.5% to 27.8%, was achieved at a cutting plane angle of α = 75–80°. The graphical modelling method we developed accurately reflects the actual behaviour of the objects. Our hypothesis was proven valid, and the research aim was successfully achieved.