It found that thefts of this vehicle rose by 34% in 2021, and is on course to increase again this year, with the overall cost of this crime rising 87% to £2.6m.
Rebecca Davidson, rural affairs specialist at NFU Mutual, said: "We've been insuring Land Rovers since they first appeared on British farms, and their iconic status makes these vehicles a regular target for both opportunistic thieves and organised criminal gangs.
"We know that when prices go up, thieves are quick to cash in and the decrease in rural theft that we saw over lockdown is well and truly over."
NFU Mutual is now working with the National Vehicle Crime Intelligence Service (NaVCIS) to help track down thieves and recover stolen vehicles.
DC Chris Piggott of NaVCIS said: "We are particularly concerned that the older Land Rover Defender models, the workhorses which are so important to farmers' everyday activity, are at risk because of a lack of modern security systems. Owners should therefore fortify their vehicles as much as possible, using a combination of measures such as immobilisers, tracking devices and pedal and steering wheel locks.
"It's also common to see vehicles stripped for parts in situ, but good site security and simple, cost-effective measures can make life difficult enough for thieves for them to abandon their attempts."