The amateur-built airplane sustained substantial damage during a forced landing to a cornfield after an aborted landing. The pilot reported that he had finished conducting a set of flight program tests for the experimental airplane he had built. He was flying the tests over a 1,000-foot grass airstrip and when he finished the tests, he proceeded to land on the grass runway. He reported that he was high on final and when the airplane touched the ground, he realized that he did not have enough runway remaining to stop so he aborted the landing and applied power for takeoff. There were power lines at the departure end of the runway and the airplane was not going to clear them. He turned left but another there was another set of power lines that the airplane was not going to clear. The pilot slipped the airplane and attempted a forced landing to a cornfield. The left wing impacted the ground and the propeller disintegrated. The pilot reported that the winds had changed since he had departed on the flight, and there was a tailwind when he attempted the landing. The airstrip did not have a windsock.