While approaching the private grass strip to land, the airplane collided with slightly higher terrain. The pilot reported that he had lined up with the grass strip and the airplane developed a sink rate. He increased the throttle control, however the airplane still settled and landed short in a field. In a telephone conversation with the pilot, he reported that he added power but that it was too late. In addition, prior to the day of the accident, the airplane had not flown for about 2 years. The pilot had flown the airplane for a short flight before returning to pick up the passenger for the accident flight. Examination of the airplane by the responding Federal Aviation Administration inspectors did not identify any mechanical malfunctions. The pilot did not have a current flight review and the airplane did not have a current inspection.