I highly recommended you read this article from Jonathan Rupprecht: Drone Sprayers: Uses, Laws, & Money Saving Tips (2022)
Jonathan Rupprecht is a practicing aviation attorney, a FAA certificated commercial pilot (ASEL & AMEL), flight instructor (CFI & CFII), and a contributor at Forbes.com for Aerospace & Defense.
Jonathan is a former professor at Embry-Riddle Aeronautical University. His articles have been cited by Newsweek, Politico, and The Hill, and he had media appearances in Forbes, NPR, & Marketwatch.
Jonathan has also made a series of video course here to help you preparing Part 107 certificate test: Airspace & Chart Reading for Drone Pilots