THE ACFT COLLIDED WITH A DIRT BANK AFTER LOSING ALT DURING THE INITIAL CLIMB AFTER TAKEOFF FROM A DIRT ROAD. THE PLT INDICATED THE ACFT BECAME AIRBORNE AFTER AN APRX 800 FT GROUND RUN AND CLIMBED TO AN ALT OF 10 FT AGL. THE ACFT THEN ENCOUNTERED A GUST OF WIND AND SETTLED 6 FT. THE ACFT STRUCK A 4 FT DIRT BANK LOCATED AT A BEND IN THE ROAD SHEARING OFF THE NOSE GEAR. THE ACFT THEN LANDED IN SOFT SAND AND NOSED OVER. THE PLT'S ACCIDENT REPORT INDICATED THAT THE ACFT WAS LOADED WITH 88 GLLONS OF FUEL AND THREE PERSONS ON DEPARTURE FROM THE DIRT ROAD, AND THAT THE TEMP WAS APRX 75 DEGREES F (24 DEGREES C) AT THE 5,500 FT ELEVATION. ACCORDING TO THE OPERATORS MANUAL, FOR A GROSS WEIGHT OF 2,700 LBS, A TEMP OF 20 DEGREES C AND A PRESSURE ALT OF 5,000 FT, A MINIMUM GROUND ROLL DISTANCE OF 930 FT WOULD BE REQUIRED TO ACCOMPLISH A SHORT FIELD TAKEOFF.