[The Old Hoosier]

It's by design, surveying of land grants, I believe. Also makes it pretty hard to get lost. :-)

I've always been curious about the fact that everyone farms in a circular manner as you get out toward Western Nebraska and Colorado.

[Tijeras_Slim]

The circles are caused by the irrigation system. A big wheeled above ground pipe with sprinklers on it that pivots around a central axis like a clock hand. I'll find a pic and be right back.

[mcvey]

Irrigation helps encourage the circular farming. There may be other reasons.

[dennisw]

I've always been curious about the fact that everyone farms in a circular manner as you get out toward Western Nebraska and Colorado.

Center pivot irrigation. Used in dry areas.

http://cff.wsu.edu/Project/galleryirrigated.htm

[bert]

......everyone farms in a circular manner ....

Think pivot irrigation

I flew from Phoenix back east last week and saw all this in detail. Some irrigate a quarter section and a few irrigate a whole section or 4 times as much.