That is correct. While there are Federal Regulations on pesticide applications, each State has their own set of regulations for pesticides and several have regs on fertilizer applications. In many cases there is confusion as to how to interpret these regulations. The only source to trust is the Department in your State that is responsible for enforcing pesticide regulations.
Google pesticide regulations followed by your State's name and you should find a phone number to get you started.
For example, here in NJ you do not need a pesticide license to apply pesticides which are exempt from EPA registration under FIFRA 25(b) whether it is organic or not. However some organic pesticides do have an EPA # and therefor do require a pesticide license. We also have a fertilizer law which requires certification to apply fertilizer, it also limits how much organic matter can be applied. The fertilizer law is not enforced by the same agency as pesticides. Other States are set up totally different.
The nation that destroys its soil destroys itself.
Franklin D. Roosevelt