Let's Go Gliding with the SSA

On Wednesday, May 30, 2012 11:36:02 AM UTC-5, C-FFKQ (42) wrote:
On Tuesday, May 29, 2012 4:33:09 PM UTC-4, Frank Whiteley wrote:
http://www.youtube.com/watch?v=aeOKjjaMCP0

Dumb question for today:
At around 2 minutes, there are rectangular fields with green circles... why are the crops planted in circles instead of using the full field?

-John (who's only ever seen crops filling the field area)

Most of the farmland in the US west of the Mississippi requires irrigation in order to be able to grow much at all. The most common type of irrigation is a center pivot arm that rotates around the middle of the field, hence the circular shape. Of course the land was divided up in most places on 1 mile grids back in the Pioneer days so the corners have gone unused. In some places the corners are still planted with some crops, although further west and south the corners are just left to die since it is not economical to grow anything on non-irrigated land. Generally the corners are the preferred landing spots unless they have been left for wild for a long time, in which case you want to land tangent to the circle and avoid the deep ruts that the tires from the center pivot leave.