On May 31, 1998, at 1700 central daylight time, a Cessna 150L airplane, N19271, was substantially damaged while landing near Pearland, Texas. The non-instrument rated private pilot, sole occupant of the airplane, was not injured. The airplane was owned and operated by Fancy Flights of Pearland, Texas, under Title 14 CFR Part 91. Visual meteorological conditions prevailed for the personal flight for which a flight plan was not filed. The local flight originated from the Clover Field Airport, near Pearland, Texas, at 1615. According to personnel at Clover Field, while landing on sod runway 14L, the 400 hour private pilot mistook the freshly mowed area to the east of the runway 14L for the approved landing area. During the touchdown, the airplane impacted a shallow depression running perpendicular to his path and the airplane bounced up in the air. On the second touchdown, the airplane impacted a drainage ditch resulting in the collapsing of the nose landing gear. According to the FAA inspector that traveled to the accident site, the confines of the 2,800 foot sod runway were difficult to define due to the lack of usage. He added that the grass was all the same tone of green as most of the surrounding area. Additionally, the worn out areas normally found in the vicinity of the touchdown zone, as well as along the runway centerline, were missing. Those visual cues normally assist pilots in defining the confines of the runway. Two sets of freshly painted tires were found on both approach ends of the runway. The investigation determine that the pilot was home-based at Clover Field; however, it could not determine if the pilot had previously used sod runway 14L. The pilot's overall familiarity with the airport could not be established. Examination of the airplane by the FAA inspector revealed that the propeller, engine mounts, rudder, and the nose landing gear assembly were damaged. The engine firewall sustained structural damage.