THE PILOT REPORTED A 300 RPM DROP AND A LOSS OF POWER DURING INITIAL CLIMB AFTER TAKEOFF FROM A PRIVATE STRIP. HE STATED THE AIRPLANE WAS NOT CAPABLE OF SUBSTAINING FLIGHT AND HE ELECTED TO LAND STRAIGHT AHEAD IN A MAIZE FIELD. DURING THE LANDING ROLL, IN SOFT TERRAIN, THE AIRPLANE NOSED OVER AND SPUN 360 DEGREES. THE CAUSE OF THE POWER LOSS WAS NOT DETERMINED.