The 9,905-hour commercial pilot had completed an aerial application flight and was returning for the second load. During the landing on a private grass airstrip, the tail-wheel equipped airplane started to slide. The pilot stated that the grass was wet from the morning dew, and that he could not get the airplane to stop. The airplane subsequently slid into a small levy and culvert, resulting in separation of the left main landing gear. The airplane received substantial damage and came to rest in the inverted position.