On July 2, 2007, at 1456 eastern daylight time, a Ayres Corporation S2R-T15, N3088K, operated by Coney Ag Service as an agricultural airplane, received substantial damage on impact with terrain during a forced landing onto an adjacent soybean field while spraying a corn field. The pilot reported a loss of engine power. Visual meteorological conditions prevailed at the time of the accident. The 14 CFR Part 137 aerial application flight was not operating on a flight plan. The pilot was uninjured. The local flight originated from Marion, Indiana, about 1426. The pilot stated that the airplane experienced a loss of engine power during a spray run approximately 30 minutes after departure. He then performed a forced landing on a soybean field during which the airplane contacted a creek bed. According to the Federal Aviation Administration, the pilot reported that the engine began to smoke from the exhaust. Witnesses reported seeing white smoke from the airplane. Examination of the airplane revealed the chemical bay was empty, the right fuel tank was damaged and contained no fuel, and the left tank was intact and contained fuel. The fuel selector was on the right tank. There was no airworthiness certificate on board the airplane.