What you say makes a lot of sense, but since that potato harvest is done for the year, why not add the trace minerals and alkalyze now? Especially in fields where the problem has not started, head off future problems.
This is also another good reason for crop rotation, but potatos are so darned profitable especially with the new sellers coops keeping the proces high.
I do agree with the need to look at electricity and would be glad to work with an interested party. It would need to be a field with an automated pivot irrigation system. Dragging a couple of electrodes behind a tractor might work for a small area but the speed would have to be slow (meters per hour).