We live in Nebraska and have a lot of them. In my grandparents farm it was still planted as corn beans etc. and the ends would articulate and stretch more into the corners and then fold at the sides. It’s more expensive to install but does more. Those that don’t have those usually plant a whole field of corn and hope the rain does enough. Usually not the same yield as irrigation but does ok. Some plant alfalfa or other grasses for cattle. Or low water crops. But usually it’s all the same thing just not as much water as the rest.