SDCL § 38-19-27: Sales and exchanges to manufacturers and mixers exempt from requirements.

Nothing in this chapter shall be construed to restrict or avoid sales or exchanges of commercial fertilizers to each other by importers, manufacturers, or manipulators who mix fertilizer materials for sale, or as preventing the free and unrestricted shipments of commercial fertilizers to manufacturers or manipulators who have registered their brands as required by the provisions of this chapter.