The pilot reported that while establishing the second boundary along the eastern edge of a field where he was conducting an aerial application, the airplane struck power lines. Following the collision with the power lines, the airplane turned to the left and impacted terrain in a flat attitude, which resulted in structural damage to all four wings and fuselage. The pilot stated that there were four sets of power lines near the field; however, the upper right wing blocked his view from the power lines the airplane struck. No preimpact mechanical malfunctions were reported that would have precluded normal operation of the airplane.