The pilot stated that on the day of the accident he had sprayed 13 loads of fertilizer and was beginning the 14th load when the accident occurred. The pilot informed the loading crew to load 400 gallons of fertilizer, which was the same amount that he had used on the previous flights. The pilot initiated the takeoff and the airplane became airborne, but was unable to gain enough altitude to clear the corn crop at the end of the airstrip. The airplane received substantial damage to the fuselage when it settled into the corn. The pilot reported that after the accident, it was determined that the hopper had been filled with 480 gallons of fertilizer. The pilot stated that since he cannot see how much fertilizer was loaded from his seat, he has to trust the loading crew to properly load the fertilizer. The pilot reported there were no mechanical issues with the airplane that would have prevented normal operation.