Simulation of soil dynamic properties of a seed opener using the discrete element method (DEM)

Abstract

Soil disturbance and draft force are important soil dynamic properties and performance indicators for a seed opener. In this study, a soil-opener model was developed to simulate soil dynamic properties of a hoe type seed opener using the discrete element method (DEM). To validate the model, a paired-row hoe opener was tested in a sandy loam soil at a working depth of 40 mm and a travel speed of 7 km/h. Soil disturbance characteristics (maximum soil surface roughness and soil cover depth) and draft force of the opener were measured. The model results agreed well with the test results, with relative errors under 10%. The validated model was used to compare the soil dynamic properties among a single-row opener, a side-band opener, and a paired-row opener. The results showed that the single-row opener produced a smoother soil surface, more soil cover for seeds, and lower draft force, when compared to the other two winged hoe openers. Further simulations were performed to examine soil dynamic properties as affected by the wing and face angles of opener. Varying the wing angle of an opener made significant differences in the resultant soil dynamic properties, whereas the face angle had little. To improve a winged opener, one should select a wing angle of 5º and a face angle of 50º for the soil condition studied.