Seed displacement after impact on a soil surface

Abstract Experiments are described in which the trajectories followed by various seeds after release from a metering mechanism were established. Seeds were allowed to impact on to soil surfaces at known impact velocities and angles and the amount of displacement due to bouncing and rolling measured. The impact velocity and angle, the nature of the soil surface and seed type all affected the mean displacement and the displacement variability. Minimum displacement occurred at low impact velocities and for impact angles between 75° and 85°. Displacement was less for sheared surfaces than pressed surfaces, and for small irregularly shaped seeds than for large spherical seeds.