A ground engaging agricultural tillage blade having a central opening adapted to be attached to an implement for rotation about a substantially horizontal axis of rotation the blade having an outer periphery and reinforcing flutes disposed in the plate from a location substantially at the outer periphery to a location adjacent the central opening. The blade can be used with a hub disposed around the central opening, a hub that covers at least a portion of the flutes or a spacer on a shaft extending through the central openings of adjacent blades, the spacers extending radially outwardly by a distance sufficient to place a portion of the spacer in abutment with at least a portion of the flutes.
