In a written statement, the pilot reported that he attempted to take off at a private airfield. The gravel runway was lined on both sides with tall grass. During the takeoff roll, the airplane drifted to the left into the grass, and the pilot attempted to correct course. The airplane drifted into the grass on the right side, hit a wire fence and a dirt berm, and nosed over. The pilot indicated that the airplane and engine had no mechanical failures or malfunctions during the flight.