In the simulation analysis of the lily harvesting process, the intrinsic parameters of the lily bulb and the contact parameters between the lily bulb and the lily mechanized harvesting equipment (Q235 steel) are deficient. Thus, the three-axis size, density, moisture content, Poisson’s ratio, elastic modulus, and other parameters of lily bulbs are measured in this paper with lily bulbs as the research object. Moreover, the discrete element model of the lily bulb was established using 3D scanning technology. The contact parameters between the lily bulb and Q235 steel were calibrated through bench test and simulation parameter test. The relative error between the measured value of the lily bulb accumulation angle and the simulated value is taken as response value to calibrate three parameters (collision recovery coefficient, static friction coefficient, and dynamic friction coefficient between lily bulbs). A regression model of the relative error of the stacking angle and three parameters is established, and the response surface is optimized. The results demonstrate that collision recovery coefficient, static friction coefficient, and dynamic friction coefficient between lily bulb and Q235 steel are 0.301, 0.423, and 0.063, respectively; these coefficients between lily bulbs are 0.455, 0.425, and 0.158, respectively. Additionally, a better combination of parameters is adopted to perform the simulation stacking test. The measured stacking angle is 32.31°, which is 0.34% in error with the stacking angle obtained by the physical stacking test. The test results suggest that the discrete element model and contact parameters of the lily bulb can be used in the discrete element simulation test. Furthermore, these research results could provide references for simulation tests, such as mechanized harvesting and post-harvest processing, of lily.

To address the problem whereby the size of the hole formed by the existing hole-forming device of hole-punching transplanters is significantly inconsistent with the theoretical size as it is impacted by the inserting and lifting methods, a scheme for eliminating the forward speed of the whole machine by the horizontal linear velocity of reverse rotation of the hole-forming mechanism is proposed to vertically insert and lift the hole-forming device in accordance with the working characteristics of hole-punching transplanting and the agronomic requirements of rapeseed transplanting. In addition, a novel type of reverse-rotating soil-taking-type hole-forming device for the pot seedling transplanting machine for rapeseed was developed. A test bench for the hole-forming device was set and its effectiveness was verified in the soil bin. It was found, from the test results, that, when the forward speed of the hole-forming device was between 0.25 m/s and 0.45 m/s, the average qualified rates of hole forming of the device were 95.2%, 94.0% and 93.3%, respectively; the average change rates of the hole size were 2.3%, 2.9% and 5.5%, respectively; and the average error between the theoretical value of effective depth and the experimental value was between 2.0% and 5.6%. The average angle between the hole-forming stage trajectory of the hole opener and the horizontal direction at different forward speeds was higher than 88.0°; the coefficient of variation was between 0.16% and 0.64%; the perpendicularity of the hole-forming operation was high; the change rates of soil porosity of the hole wall were between 8.2% and 9.3%; and the average soil heave degrees at the hole mouth after the completion of the hole-forming operation were 3.9%, 4.1% and 4.2%, respectively. The average soil stability rates of the hole wall were 91.9%, 91.2% and 91.0%, respectively. The different performances of the hole-forming device were confirmed to meet the requirements of rapeseed pot seedling transplanting. This study can provide a reference for the structural improvement and optimization of the hole-punching transplanter for rapeseed pot seedlings.

The mechanized harvesting of lily fruit in Southern China is affected by a high damage rate of lily fruit and low rate of soil breakage. The existing fruit–soil separation device is not suitable for heavy soil in Southern China. This study aimed to design a flexible fruit–soil separation device that can effectively reduce the damage rate of lily and improve the crushing rate of the soil. Thus, it would meet the requirements of southern lily fruit harvesting. In this study, the soil breaking rate and lily damage rate in the fruit–soil separation were taken as the assessment indexes, and the linear speed of the front conveyor belt, the inclination angle and the rotating speed of the fruit–soil separation device were recognized as the test factors. By performing the Box–Behnken test, three-factor and three-level experimental research on the fruit–soil separation device of the lily harvester was conducted. On this basis, a multiple regression model of the assessment indexes to the respective was built, the effect of various factors on the operation quality was analyzed and optimal operation parameters were determined. When the optimal parameter was adopted in the test (e.g., the linear speed of the front conveyor belt, the inclination angle and the speed of the fruit–soil separation device reaching 1.2 m·s⁻¹, 36° and 98 r·min⁻¹, respectively), the soil crushing rate was 92.8% and the lily damage rate reached 8.9%, and the fruit–soil separation effect satisfied the requirements of lily fruit harvest. The results could be referenced for other subsoil fruit harvesters and fruit–soil separation devices under heavy clay soil in Southern China.