Rice fields, around here at least. That's always been very labor intensive. They do use tractors to do some of it, but around the periphery of every field it's still done manually. Rice fields are very different from wheat production.
In my country strawberries are picked manually. There's yet no mechanical solution which can do what humans can, with respect to quality and more. And that's already a problem, without seasonal immigration there will be no strawberries on the market, simple as that. There are many other kind of work which still requires a young healthy work force.
