The private pilot was on initial climb after departing from a farm airstrip when, at approximately 75 feet above the ground, the engine lost power. The pilot made a partial power landing in a newly planted wheat field. The airplane flipped over on its back causing substantial damage to the empennage, both wings, rudder, and vertical fin. Both occupants reported they were not injured. The FAA inspector that responded to the scene reported that there was adequate fuel on-board and no obvious reason for the loss of engine power.