Abstract: A soil tilling device, in particular a rotary tiller, a motor hoe or a motocultivator of the kind comprising one or more soil blades (2), assembled on a rotating driven shaft (1), apt to work the soil, avoiding the accumulation of either twigs, weeds, pruning remains or any kind of branches at the soil blades and at the shaft, since twigs and others undergo a reduction in size and length preventing the twining thereof due to one or more subsidiary blades (4, 9) placed at the sides of said soil blades (2), at said shaft (1).