The 14,000-hour pilot shut down the 750-horsepower engine on the agricultural airplane after the engine began surging between idle and full power. He stated in the NTSB Form 6120.1/2, that he elected to divert to a nearby airport. The pilot shut down the engine prematurely which resulted in a higher than desired altitude with a high approach airspeed. The airplane touched down long and fast on the 4,000 foot long runway, resulting in an overrun. The pilot attempted to intentionally ground loop the airplane to avoid overrunning the departure end of the runway; however, he was unable due to the surface of the runway being damp. The airplane overran the departure end of the runway, collided with trees, and came to rest in a creek. Weather at the time of the accident was reported as clear skies, calm winds, temperature of 72 degrees Fahrenheit, and altimeter 29.87 inches of Mercury.