The pilot reported that this was the first time landing his multi-engine airplane on his private grass airstrip. The flight handbook revealed that the required landing distance was about equal to the full length of the runway. The pilot reported performing a stabilized approach, with an intended touchdown point 200 feet down the runway. As he approached short final, the airplane began to sink, and he increased engine power. This did not arrest the descent, so he applied full engine power; however, the airplane touched down short of the runway and struck a fence post with the left wing, which resulted in substantial damage. The pilot reported no mechanical malfunctions or failures with the airframe or engine that would have precluded normal operation, and further stated that the accident could have been avoided if he had performed a go-around at the first indication of altitude loss.