The pilot reported that he completed a 200 nautical mile cross country flight, then returned to the departure airport for touch-and-go landings. During the second touch-and-go, the engine experienced a loss of power about 200 to 300 ft agl. The pilot was unable to restore engine power and executed a forced landing to a field, which resulted in substantial damage to the fuselage and empennage. The pilot reported that there were no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation. After the accident the pilot reported that he did not switch the fuel selector to the tank with available fuel. The airplane contained about 36 gallons of fuel; 18 gallons in each fuel tank. The total flight time was about 2 hours and 20 minutes. The estimated fuel consumption rate for this engine was 8 gallons per hour.