On October 20, 1999, at 0845 central daylight time, a Cessna A188B, N731PU, sustained substantial damage when it struck a berm, brush, and trees, before nosing over. Subsequent to the impact, the airplane's engine lost power while maneuvering following a chemical application pass to a farm field near Sprague, Nebraska. Visual meteorological conditions prevailed at the time of the accident. The aerial application flight was being conducted under 14 CFR Part 137. No flight plan was on file. The pilot sustained minor injuries in the accident. The local flight originated from the pilot's private airstrip at Adams, Nebraska. In his written statement, the pilot said that he was flying to the north around 20 feet above the ground, when the engine quit. The pilot said he checked the throttle and pulled on the flaps to slow the airplane. "There was no place to land, so I went into some trees and hit a ditch which flipped me over." The pilot told a Federal Aviation Administration (FAA) inspector that he had just completed his final pass on the field and was getting ready to return to his airstrip when the engine just quit. "There was no sputtering or warning. It just quit." A FAA inspector examined the airplane at the accident site. The airplane was resting upside-down in a field, next to a ditch. Both wings were bent back. The left wing spar was bent aft. The main landing gear were twisted. The top of the airplane's fuselage was crushed inward slightly. The vertical stabilizer and rudder were crushed inward and bent over. Flight control continuity was confirmed. Examination of the airplane's engine revealed that the bottom spark plugs were lead-fouled, and rusted. Examination of the other airplane systems revealed no anomalies. Further examination of the engine revealed that the fuel strainer filter was clogged with debris identified as dirt and rust. An examination of the airplane's maintenance records showed that several airworthiness directives applicable to the airplane had not been complied with. Additionally, several airplane system items requiring annual inspection under 14 CFR part 43 had not been accomplished.