The pilot was landing at the remote agricultural airstrip for the first time. While on the final approach to land to the south, just before touchdown, the pilot observed a ground spray rig maneuver toward the turf runway. The airplane touched down uneventfully to the dry grass and during the landing roll, the pilot reported that the ground spray rig, "pulled out on me, not thinking it could be on the road that went around the end of the airstrip." The pilot incorrectly judged, from his elevated position sitting in the tailwheel airplane, that the ground spray rig was crossing the runway, and thought a runway incursion was occurring. The pilot applied full power and with the turbine engine acceleration lag condition, the pilot then realized that he was, "not going to have enough time" to perform a go-around. The pilot reduced the power and attempted to stop the airplane before he ran out of available runway. The airplane impacted a metal perimeter fence and sustained substantial damage to the fuselage, the right aileron, and the engine mount. The operator reported that there were no preimpact mechanical malfunctions or failures with the airframe or engine that would have precluded normal operation.