In order to further exploit the production advantages of rice throwing, this paper proposes a systematically designed throwing device suitable for integration with unmanned aerial vehicles (UAVs). The device primarily comprises a seedling carrying and connection system, a seedling pushing mechanism, and a seedling guiding device. The operational principles and workflow of the device are initially elucidated. Subsequently, an analysis of factors influencing rice throwing effectiveness is conducted, with throwing height, working speed, and the bottom diameter of the seedling guide tube identified as key factors. Seedling spacing uniformity and seedling uprightness are designated as performance indicators. A three-factor, three-level response surface experiment is conducted, yielding regression models for the experimental indicators. Through an analysis of the response surface, the optimal parameter combination is determined to be a throwing height of 142.79 cm, a working speed of 55.38 r/min, and a bottom diameter of the seedling guide tube of 43.51 mm. At these parameters, the model predicts a seedling spacing uniformity of 88.43% and a seedling uprightness of 88.12%. Field experiments validate the accuracy of the optimized model results. Experimental data indicate that under the optimal operational parameters calculated by the regression model, the seedling spacing uniformity is 86.7%, and the seedling uprightness is 84.2%. The experimental results meet the design requirements, providing valuable insights for UAV rice-throwing operations.

Sweet potato is essential for food security, but its transplanting efficiency is currently low. To improve this, we developed a belt-type transplanter that uses seedling belt technology for automated feeding, increasing efficiency by over 25%. The use of the seedling belt is key to significantly enhancing the transplanter’s efficiency. Building on seedling belt feeding, we designed a “trumpet-shaped” staggered detachable seedling belt using LDPE film. Seedlings are fixed at intervals between two film layers via thermal bonding points. Mechanical analysis showed the optimal peeling strength is 13.2 N, ensuring smooth seedling transport during transplanting. Peeling strength depends on the heat sealing temperature, time, and pressure. To optimize these parameters, we designed an experimental device and conducted single-factor experiments to determine their effects on the peeling strength and establish reasonable ranges. Results show that, at a peeling strength of 13.2 N, the thermal bonds separate smoothly without tearing the film. A three-factor, three-level orthogonal experiment further optimized the heat sealing parameters, concluding that, at 140 °C, 1.2 s, and 0.4 MPa, the average peel force of the seedling tapes obtained from the experiments was 14.31 N, at which point the peeling effect was optimal.