Lincolnshire Police say there were 13 thefts over just two days last week in the Boston and Spalding areas.
The police say thousands of pounds worth of equipment was taken by the thieves.
The haul included GPS / SAT NAV equipment Trimble 500 and 750 Nav Systems, Trimble Satellite Receivers, and TOPCON and Intelliview Computer.
All the thefts were at night and in rural areas.
Acting Detective Sergeant Walker of Lincolnshire Police said: “This trend is deeply worrying for farmers who are investing in high-tech equipment to make their farms more efficient and reduce pollution.
“In an attempt to stop thieves targeting GPS kits, some manufacturers now provide personal identification numbers (PINs) to prevent the equipment being used by others.
“Most GPS kits in use on farms today are fitted to tractors as an easily-removable accessory. To prevent thefts, farmers should remove the kit when it’s not in use and store it under lock and key.
“We would ask farmers to ensure they remove GPS kits if possible and to report any suspicious activity by calling 101, or 999 to report a crime in action.”
The NFU has also issued guidance to its members on the issue, saying farmers should:
*Remove GPS guidance receivers, aerials and antenna globes from tractors when not in use and keep them in a secure locked place whenever possible
*Consider fitting security tethers or brackets to stop units being removed
*Mark your postcode on GPS units – either with a UV pen, engraving tool or forensic marking system
*Store machinery in locked buildings where possible
*Where locking machines away isn’t an option, consider fitting mains or battery-operated alarms to cover around the perimeter of areas where machines are stored
*Record machinery serial numbers and photograph kit to help police identify stolen items and increase the chances of them being recovered