Effect of potato contact parameters on seed metering performance using discrete element method

Aim of study: To study the effect of potato surface with or without sandy loam soil on seed metering performance, we investigated the motion behaviour of the potato seed particles during the seed metering process using a self-designed across-bridge metering device by discrete element method (DEM). Area of study: Tonganyi Town, Dingxi, Gansu, China Material and methods: First, the contact characteristics of potatoes were measured using some novel devices. Second, simulations were performed under the same experimental conditions to verify the reliability of the contact parameters. Finally, the velocity and angular velocity of the seed in the seed box and the number of seeds taken by the large spoon during the taking and clearing process were analysed using ANOVA. Main results: The coefficients of static friction (SF) and rolling friction (RF) of seed particles with soil were smaller than those without soil and had the highest values between particles and plastic, followed by between particles and steel, and between particles. Further, the rates of metering single seed particle in simulation and experiment were 98.17% and 97.57%, respectively. The rate of missing seed particles was 1.83% and 2.43%, respectively; it was found to significantly decrease as RF increased from 0.01 to 0.06 to 0.12, and the resultant angular velocity and velocity also significantly decreased as SF increased from 0.1 to 0.5 to 1.0. In addition, the number of seeds taken by the large spoon also reduced. Research highlights: Therefore, potato seed particles surface with or without soil can significantly affect the seeding performance and highlight the need for surface treatment using mechanised metering.