Firefighters spent almost an hour dealing with a field blaze near Edlington, Doncaster, last night.
The fire in the field at Warmsworth Halt, reported just before 11pm, was started deliberately, said a fire service spokesman.
A number of conifers near a property in Arksey Lane, Bentley, were also set alight intentionally and took half an hour to put out.
Doncaster fire crews were called to Carr Hill, Balby, at 5am today when a pile of tyres and pallets were set on fire.
And a motorbike was the subject of an arson attack in The Crescent, Woodlands, at about 3am today.