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.

During the working process of a conventional press roller in the rice–wheat rotation area, the phenomenon of soil adhesion and a large slip rate, which are directly related to the growth and the output of the wheat, occurred widely. It was found that the geometric structure of the back surface was one of the key reasons for Carabus formosus nili exhibiting low adhesion against the soil. In this paper, lessons are drawn from the non-smooth morphology theory and bionics principle. The bionic press rollers with bionically convex hull structures were designed after learning from the geometric structure of Carabus formosus nili, which modifies the geometric structure of the conventional press roller. The three-dimensional simulation model of a bionic press roller and soil was constructed in the ANSYS/LS-DYNA software(ANSYS, Canonsburg, PA, USA) to simulate the dynamic process of the interaction between the bionic roller and soil and to verify the rationality of the design of the bionic press roller. Based on the simulation of the interaction between the bionic press roller and the soil, the main factors affecting the bionic roller were determined: forward speed, load, and structural parameters. The field tests were carried out, and the orthogonal test was used to investigate the effects of forward speed, load, and structural parameters on the operation performance of the bionic press roller. Through the orthogonal test, the primary and secondary order of forward speed, load, and axial spacing were obtained. The optimal combination was: forward speed 7 km/h, load 400 N, and axial spacing 40 mm. This study provides a new idea and reference for the design of a press roller for wheat sowing in the rice–wheat rotation area.

To address the issues of high labor intensity, excessive manpower requirements, low planting spacing qualification rates, low planting depth qualification rates, and low operational efficiency associated with sweet potato transplanting, a sweet potato seedling belt transplanter has been designed. This machine can perform multiple processes: precision tillage and ridge shaping, orderly seedling feeding from rolls, the efficient separation of seedlings from the belt, flexible gripping and shaping, precise soil covering and the mechanism of exposing seedling tips. A three-factor, three-level orthogonal test was carried out using the forward speed of the machine, the pitch of the screw belt and the rotational speed of the screw as the influencing factors of the performance test, and the qualified rate of planting spacing and the qualified rate of planting depth as the evaluation indexes. The test results indicated that the significance order of the factors affecting the qualification rate for planting spacing with the optimal combination of factors was as follows: a forward speed of 0.3 m·s⁻¹, a ribbon spacing of 60 mm, and a screw speed of 160 rpm. Field trials confirmed that under optimal conditions, the average qualification rate for planting spacing was 90.37%, meeting relevant technical standards and agronomic requirements.

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.