Crops are grown with great precision these days.
Sometimes they are sown, sprayed and harvested by machines with identical widths. So, it makes sense to have fixed tram lines down the field where each machine drives in turn. These thin sections of crop are sacrificed, but the result is that the field is processed from seed to harvest with no missing parts.
It's probably all done with GPS satellite control I expect.
In my day the fields were intersected with tractor marks at random angles and bits of the field would be yellow while the rest was lush and green.
Another unintended consequence is the local wildlife has multiple parallel motorways intersecting their narrow world. These Pheasants looked distinctly worried, as they should be - a monster sprayer was lurking just over the brow of the hill.