Numerical analysis of fertiliser motion characteristics and performance testing of a centrifugal precision fertilisation device

Point fertilisation can effectively reduce fertilisation amount and advance sustainable agricultural development compared with conventional strip fertilisation. This study involves the design of a novel centrifugal fertilisation device using centrifugal force to fill and discharge fertiliser for precision point fertilisation. The structural design and theoretical analysis of the crucial components were conducted and the principal factors influencing the effectiveness of point fertilisation were identified. A comprehensive phenomenological investigation and quantitative analysis of the different working stages of the device were conducted via discrete element method (DEM) simulation to reveal the interaction between dispenser edges and fertiliser, and a two-factor experiment was conducted to determine and validate the optimal working parameters of the device. The results demonstrated that the diagonal-shaped dispenser exhibits a better effect on filling, delivering, and discharging fertilisers than the curved and folded shapes. At a working speed of 5 km·h⁻¹ and a fertiliser point-applied mass of 4 g, the device achieved the optimal effect of point fertilisation. The device was tested under optimal working conditions in five replications. The average distribution length of fertiliser ranged from 9.3 cm to 9.8 cm, and the coefficient of variation of the fertiliser point-applied mass ranged from 3.4 % to 3.6 %, with mean values of 9.5 cm and 3.5 %, respectively. Under the same distribution density of fertiliser, the centrifugal fertilisation device saved about 61.8 % of the fertiliser compared to the grooved wheel fertilisation device when covering the same fertilisation area. This study provides a theoretical and technical reference for point fertilisation implementation.