The private pilot landed the tailwheel equipped airplane on a harvested farm field near his father's house. He said that the landing was made to an area that he had walked the day before. When he attempted to takeoff, in a different location than the previous landing, he encountered high wheel resistance due to the soft wet ground and aborted the takeoff. The pilot stated that he had not walked or inspected the area where this takeoff attempt was conducted. While attempting to taxi to the previous landing location, dirt and mud collected on the landing gear between the main landing gear leg and the tire causing the wheel to lock up as if the brakes had been applied. The pilot attempted to reduce engine power but the airplane slowly nosed over resulting in damage to the wings, fuselage, and vertical tail. In a telephone conversation the pilot he confirmed that there was no mechanical failure of the braking system and that the tires stopped rotating due to the dirt and mud between the gear leg and the tire/wheel.