A motorcyclist has been killed in a collision with a tractor and trailer on Kirton Road in the village of Blyton, north of Gainsborough.
Fire crews were called to the scene after the hay on the trailer caught fire after the crash.
Police spokesman Dick Holmes said: "The motorcyclist was certified dead at the scene, and we are now working on establishing his identity.
"We will be informing relatives once we have a firm identity for the deceased."
The tractor driver was not hurt.
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David Urpeth from law firm Irwin Mitchell said: "This was a tragic road traffic accident. Sadly, when motorcycles are involved in road crashes, the riders injuries are often serious or fatal given the lack of protection a rider has.
"The warm summer months see an increase in the number of riders enjoying their bikes and the weather, but sadly we see a corresponding increase in motorbike related road traffic accidents.
"This accident is also noteworthy as it involved farm vehicles. At certain times of the year, for example planting and harvesting, there is an increase in agricultural vehicles using the roads. This in turn leads to an increase in road crashes.
"I represent many road users who have been injured or killed in road traffic accidents. Road users can be driver, passengers, cyclists, motor cyclists or pedestrians."