I'm wanting to create a RX map with about a 20' zone around my field boarders where I run a higher preplant chemical rate for weed pressure and a lower rate on the inside of field. Are there any programs out there where I can take my JD RTK boundaries and have it create a zone x feet from boundary?  Otherwise, what programs would work good for this?  Sprayer is a JD with the exact apply nozzle. Right now, I'm manually drawing the zone and it's not very accurate since it's hard to tell how many feet line is from boarder.

Thanks