On July 21, 1997, at 1030 central daylight time, a Piper PA-36-285, N268JW, operated by Jerry Waltz, Inc., sustained substantial damage during a forced landing near Hill City, Kansas. The commercial rated pilot reported a sustained partial loss of engine power during the initial climb. The pilot reported no injuries. Visual meteorological conditions prevailed for the local CFR 14 Part 137 aerial application flight. There was no flight plan on file. The flight was originating at the time of the accident. The pilot told Federal Aviation Administration officials that the purpose of the flight was for the application of chemicals. He said that that during initial climb the engine partially lost power and that he dumped the load in an attempt to maintain flight. He said that the power loss prevented continued flight and he elected to conduct a forced landing in a field. The airplane sustained substantial damage during the forced landing in the terraced field. Subsequent to the accident, the engine was examined and one cylinder had low compression.