Apparatus and method for subgrade preparation

A subgrade preparation apparatus for preparing a subgrade surface for concrete to be placed thereon includes a base unit positionable on a support surface adjacent to a targeted subgrade area, an extendable boom extending from the base unit, and a subgrade head assembly adjustably mounted on the extendable boom. The subgrade head assembly includes a framework, a plow and a material moving device for moving material toward at least one side of the subgrade head assembly. The subgrade head assembly includes a plow end plate movably attached at an outer end of the plow and movable to a position where the plow end plate is generally vertical and forms an end portion of the plow to limit plowed material from flowing around the outer end of the plow as the subgrade head assembly is moved over and along the subgrade surface at the targeted subgrade area.