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.

Objective: This study was conducted to address the harsh working environment of agricultural machinery and improve the wear resistance of soil-contacting components such as rotary tiller blades, thereby extending their service life. Method: Plasma-cladding technology was employed to prepare an iron-based wear-resistant coating on the surface of rotary tiller blades. The following parameter combination was optimized using response surface methodology (RSM): a cladding current of 144A, a cladding speed of 23 mm/s, a powder feeding rate of 23 g/min, and a cladding distance of 12 mm. The microstructure morphology, phase composition, microhardness, and wear resistance of the wear-resistant cladding layer were investigated. Results: The results indicate that the interface of the cladding layer is clean and free from significant porosity or defects, exhibiting good metallurgical bonding with the substrate. The primary phases identified in the cladding layer include α-Fe, Cr₇C₃, Cr₂Fe₁₄C, and Cr-Ni-Fe-C solid solutions. The average hardness of the cladding layer is 1171 Hv0.5, approximately 2.9 times that of the substrate. In wet sand–rubber wheel wear tests under identical conditions, the weight loss of the cladding layer is only 1/21 that of 65Mn steel, with minimal wear morphology. Field trials showed that the wear of the cladding layer rotary tiller blade was reduced by 24.5% compared with the unclad blade. The presence of the cladding layer significantly protected the integrity of the cutting edge, ensuring the functionality of the rotary tiller blade in cutting and throwing soil; thus, its original appearance was maintained even after prolonged wear. The findings of this study can provide a valuable reference for the enhancement of wear resistance for other soil-contacting components.

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.