Abstract: The invention is directed to an apparatus for treating soil by breaking up soil clods and compacted earth. The apparatus includes a carrier frame angularly maneuverable in relation to the longitudinal or forward direction of movement of the apparatus, and in which are mounted at least two rotating parallel helical blade elements, of which at least one rolls on the ground. Each of the helical elements, whether of the same or different diameters, has a pitch and a diameter such that, when in joint rotation, the spires of one of the blade elements remains in close contact with the spires of the other blade element or elements. Each of the helical blade elements is operatively connected mechanically for simultaneous rotation with the other blade element or elements. The operative connection between the blade the blade elements is, for example, achieved by endless chains trained about pinion fixed on respective ends of rotating shafts to which the helical elements are fixed.