I see the this option is very similar with farming simulator and have almost the same bugs as that game.
There was a game named agrar simulator which had a perfect worker option. You select the worker filed, tractor, equipment and filed. That worker would start automatic from your warehouse or whenever you have the tools for that job, goes on the field and finish the job without a problem, comes back, leaves the tools in the warehouse and leaves. You should look into that system, a good one. No need to go on a field select and so on everything is done though a menu and since you implemented a tablet option it could be added a option for that.
The game has good potential, way more better that fs but it's need it a lot of work.
Also agrar had good simulation on terrain, not just a image bump but actual terrain deformation. Loved that game but it's abandoned.