The pilot's first attempted departure from his property strip was abandoned when he encountered strong downdrafts at about 150 feet above the ground. Sufficient strip length remained to permit a safe landing straight ahead. The pilot then attempted a second take-off, but again encountered severe downdrafts. On this occasion a landing back on the strip was not possible. The pilot decided the aircraft could not outclimb the terrain ahead, and selected an open area just to the right of his track in which to land. The nosegear and the right maingear were torn out when the aircraft touched down on the soft surface and groundlooped to a halt. No evidence was found to indicate that the engine was not capable of delivering full power during the take-off attempts. The wind at the time was strong and gusty, and conditions were conducive to downdrafts and wind shear. The pilot had not waited for the conditions to abate before commencing the second take-off.