On June 6, 2012, approximately 1300 central daylight time, a Beech 35-A33, N334Z, registered to KCN Aero Club INC., of Kansas City Missouri, was substantially damaged when it impacted a fence after takeoff from runway 17 at the Gardner Municipal Airport (K34), Gardner, Kansas. The airline transport rated pilot and the airline transport rated passenger were not injured. Visual meteorological conditions prevailed in the vicinity and a flight plan was not filed. The flight was conducted under the provisions of 14 Code of Federal Regulations Part 91. The flight was intended to train and familiarize an aero club member in the club-owned Beech 35-A33. After about 1.2 hours of uneventful local flying, the airplane was landed and refueled. After a successful runup with no anomalies noted, the pilot set up to demonstrate a soft field takeoff from the 3,237 foot long grass runway. As the airplane lifted into ground effect, the pilot thought that the acceleration was not as he expected. As the airplane continued, the pilot knew that the airplane was not going to make it over a fence near the departure end of the runway. The airplane collided with the fence and came to rest in a pasture resulting in substantial damage to wings. Examination of the airframe and engine after the accident did not show any evidence of mechanical malfunction or abnormalities that could explain the pilot's report of diminished performance during takeoff. Additionally, the pilot reported that the airplane was operating normally during the earlier flight and during preflight runup just prior to takeoff. The takeoff was to the south, heading 170 degrees. The pilot reported that the wind was variable from 090-110 degrees at 8-10 knots. The automated weather report from New Century Airport (IXD), located 3 miles from the accident site, reported the wind from 120 degrees at 6 knots. The airport manager of K34 reported that he did not see the accident in person. He was sitting in his office when he received a phone call from the tower chief at New Century (IXD) asking if he knew anything about an airplane off the runway. Just before he got the phone call he heard that another aircraft had taken off from runway 8 at Johnson County Executive Airport (OJC). OJC was located 11 miles to the east of K34. He thought that was odd because the wind had been out of the south. He then checked the windsock K34 and it was showing wind from the North Northeast. He estimated that he saw the windsock about 5 or 10 minutes before getting the call from the tower chief from New Century. On the submitted NTSB Form 6120, Recommendation Section, the pilot stated that if the airplane was not performing as expected, for any reason, the takeoff should be aborted as soon as there was an indication of abnormal performance.