The pilot reported that after loading about 100 gallons of jet fuel and about 420 gallons of aerial spray product, he began a takeoff roll on the 2,506 ft asphalt runway. The pilot attempted to rotate the airplane with about 300 ft of runway remaining. Unable to climb out of ground effect, the pilot attempted to jettison the aerial spray product during and after takeoff. The airplane was airborne for about 200 yards before it settled into the soybean field. The airplane sustained substantial damage to the wings, empennage, and fuselage. During an interview, the pilot stated that he took off with a tailwind with one notch of flaps and remembers over torquing the engine. He reported that he likely rotated too soon, was slow, and never got out of ground effect. The pilot reported, and a postaccident examination corroborated that, there were no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation.