A guy I worked for one year had a sprinkler with big narrow metal spoked wheels, that you had to move by hand. It was supposed to turn them all the way along but it didn't quite work so you had to walk along and move it little by little in a long S-pattern.
I didn't end up doing the summer irrigation, but I kept having to move the sprinkler out of the way to work the ground and seed it. Of course later on you would have had to either shut off the pump from the river, or else dress appropriately and enjoy cooling off from 95* heat