The second one is essentially the same material as the first, just slightly re-edited.

In the third report the 20cm deeper channel around the edge would have been made by a roller or wheel to which a rope was attached in order to form the circle. One person stands in the middle of the circle holding the rope and another pushes the roller carefully around the edge. Once that has been done the rest of the circle can be flattened with a wooden fencing rail. Access to the circle is via the tramlines. Grass that has been stood on will recover in a few hours especially if it's short, as it usually is in tramlines because it's in competition with the crop and is regularly flattened by tractor wheels.

People who want to believe in mysteries will see the "evidence" the way they want it and will ignore (or not report) anything that doesn't fit. It's fairly obvious from the wording of the article that the farmer and the reporter wanted a mysterious story.