During a crosswind turn, shortly after takeoff, the pilot noticed that the fuel pressure gauge was registering a loss of fuel pressure and the engine was experiencing a smooth loss of power. The pilot said that he turned on the emergency boost pump and verified that the fuel selector was positioned to the left fuel tank. The pilot said that the engine quit altogether and he landed straight ahead in an open area. The pilot said that he visually examined the tanks prior to takeoff and reported that the left tank contained about 15 gallons and the right tank was empty. The aircraft was examined by an FAA airworthiness inspector. He reported that only seven gallons (approx 1/4 tank) was drained from the left tank and no fuel was in the right tank. The owner's manual for the aircraft states that with 1/4 tank or less, uncoordinated flight in excess of one minute can cause fuel starvation and engine stoppage.