Abstract: An improved moldboard plow having a soil engaging shank mounted behind the moldboard plow bottoms. The soil engaging shank is extendable to a depth of six to eight or more inches below the point reached by the moldboard plow bottoms. Both the moldboard and the shank are fitted with trip mechanisms to raise them up when either or both encounter a hard buried object. Preferably the shank includes a hydraulic cylinder for raising and lowering the shank as needed.