I just spoke to Dan Danielson - 615-837-5135. He said there are no requirements for use of pure fertilizers in TN by a company.
He said be careful that the fertilizer doesn't have herbicides impregnated in the fertilizer, because then of course you will need to have a licensed pest control operator working full time within your company or be an operator yourself and be chartered with correct insurance.
When I started this thread, I thought that fertilizer required the pesticide license and was not even asking about pesticides. I do now want to apply pesticides as well as fertilizer.