Rare documentary: Crop Circles Message from Space? (1995)

In the 70s years, along the entire United Kingdom started to appear symbols and perfect figures drawn in the wheat fields, with a ability apparently out of the human capacity. Later two farmers affirmed who did it as a joke taking advantage the fame of the UFOs sightings in those times, making the circles and figures with ropes and little woods. Then, why in some circles exist signals of high radioactivity?, how a farmer can to curve a caring of wheat not breaking it?. And most important: if it's confirmed as fraud, why Crop Circles follow appearing around the world? Would an alien lifeform try to talk with the human race?