The commissioner may exempt certain nursery stock, nurseries, or persons from all or part of the provisions of this chapter. Exemptions from licenses and fees may include:
1. Persons growing and propagating nursery stock for research or experimental purposes;
2. Soil conservation districts selling nursery stock for the prevention of soil and wind erosion or other conservation plantings; and 3. Persons growing nursery stock for noncommercial purposes or that the commissioner designates as exempt.