I once heard a story that sounds plausible, but I have some doubts. Can anyone confirm this?

It goes: In some places the boundary between Canada and the U.S. is visible from the air—perhaps even from a satellite—because of differences in farm subsidies between the US and Canada. On one side, farm fields are planted right up to the border, but on the other side, land of equal fertility is uneconomical to farm.

I figure if this is true, you ought to be able to see it with Google Maps, but I wouldn't know where to look.