Fertilizer can improve the yield of crops per unit area, and uniform fertilizer discharge can improve the fertilizer utilization rate. Therefore, it is meaningful to improve the performance of fertilizer-discharge devices in order to improve the modernization level of crop field fertilizer management. To address the problems of operational smoothness, stability and poor uniformity of fertilizer discharge, and other difficult problems encountered with strip fertilizer-discharge devices, this study designs a disturbed fertilizer strip-discharge device with a vertical pendulum. The main factors affecting the performance of fertilizer discharge were the wedge angle of the push-disturbing main pendulum bar (PMPB), the inclination angle of the aided-stirring pendulum pick (APP), the flow gap of the pendulum bar (FGPB), and the operation frequency of the swing-rod combination (SRC). The discrete element method (DEM) was used to establish a simulation model of the fertilizer device to explore the influence of the main factors on the performance of fertilizer discharge, with the coefficient of variation (CV) of fertilizer discharge uniformity and fertilizer discharge accuracy (FDA) used as the evaluation indices. The results show that the factors affecting the CV of fertilizer discharge uniformity and FDA were, in order of priority, the operation frequency of the SRC, the FGPB, the wedge angle of the PMPB, and the inclination angle of the APP. The optimal parameters after rounding were as follows: the wedge angle of the PMPB was 45°, the inclination angle of the APP was 46°, the operation frequency of the SRC was 188 times/min, and the FGPB was 4.5 mm. At this point, the model predicted that the CV of fertilizer discharge uniformity would be 10.53%, and that the FDA would be 3.19%. Using the optimal parameters for bench test verification, it was found that the wedge angle of the PMPB was 45°, the inclination angle of the APP was 46°, the operation frequency of the SRC was 188 times/min, the FGPB was 4.5 mm, the CV of the uniformity of the fertilizer discharge was 11.06%, and the FDA was 3.51%. In the test, the fertilizer-discharge device was stable and had good adaptability to different fertilizers. The results of this study can provide a theoretical reference for the development of precision strip-fertilizer application devices.

This study investigates the collision model of cassava seed stems in precision planters. Utilizing a physical property analyzer and a custom test platform based on collision dynamics principles, we measured and analyzed the forces and recovery coefficients of seed stem collisions. Mixed orthogonal and one-way tests were conducted to identify the main factors affecting the collision recovery coefficient of seed stems, including collision contact material, drop height, seed stem mass, moisture content, drop direction, and seed stem variety. The results from the orthogonal tests indicated that the factors influencing the collision recovery coefficient were ranked as follows: collision contact material > drop height > seed stem mass > moisture content > drop direction > seed stem variety. Notably, the effects of impact contact material, drop height, stem mass, and moisture content were significant, while the effects of drop direction and seed stem variety were relatively insignificant. The one-way test results revealed that the collision recovery coefficients for cassava seed stems with structural steel Q235, rubber sheet, seed stems, and sandy loam soil decreased progressively, with values for SC205 being 0.8172, 0.6975, 0.6649, and 0.6341, respectively, and values for GR4 being 0.7796, 0.7132, 0.6913, and 0.6134, respectively. Furthermore, as drop height increased, the collision recovery coefficient of cassava seed stems decreased; similarly, higher stem mass and moisture content correlated with lower coefficients. To minimize impact during critical stages of cassava planting, transportation, and processing, materials with lower recovery coefficients should be prioritized in equipment design. Incorporating rubber coatings can effectively mitigate collision effects in components such as seed supply and planting mechanisms. These findings provide valuable insights for designing and enhancing key mechanical features in machinery used for planting, transporting, and processing cassava.