Dark Harvest 3: Scarecrow
The film's opening flashback takes place in "The Tennessee Backwoods" circa 1921, where a gang of moonshiners have just killed an old woman and stolen her land for use in their criminal enterprise. Unfortunately this particular old woman happened to be a witch, and before dying she placed a curse on her property, which causes her scarecrow to come to life and dispatch the sleeping moonshiners with a variety of farming implements.
Flash forward to 1981, and a group of annoying twenty somethings ... are headed off to the woods on an annual camping outing. They plan to stay at a remote cabin in the middle of the woods ... owned by the family of one of the gang. Upon arrival the group takes part in the usual slasher film activities for a while, i.e. getting drunk, having sex, and getting on each other's nerves, until one of the gals gets her head lopped off in mid-coitus by the evil scarecrow. Turns out the cabin is on the witch's former property and her guardian is still hangin' around protecting the place. (IMDB MetalGeek)