1. Tractors. The annual fee for the registration of a tractor must accompany an application for registration and is as follows.
Tractors equipped with:
A. Pneumatic tires, 25¢ per horsepower and 25¢ per 100 pounds of weight;
B. Solid rubber tires, 25¢ per horsepower and 50¢ per 100 pounds of weight; and
C. Iron, steel or other hard tires, 25¢ per horsepower and 80¢ per 100 pounds of weight.
The minimum fee is $5.
2. Tractors used for farming. The fee for a tractor used for agricultural purposes or not customarily used on public ways is $5, except as provided in section 510, subsection 1.
3. Old homemade tractors used for farming. The fee for a homemade tractor used for agricultural purposes with motor and chassis at least 10 years old that has a body capacity of not more than 1 1/2 cubic yards and that is used exclusively for agricultural purposes is $5. Such a vehicle may not be operated on the highway more than 10 miles from the place where the vehicle is customarily kept.