Iowa does not allow baiting, period. I am not sure what you are supposed to do if you have a place that baiting was used on your property before you bought it, but I am sure the DNR would give advice on this. Also, the reason that you would remove a mineral block is because it is illegal to hunt over it.
As for the bucket of apples compared to a food plot, theres a difference between dumping apples on the ground to shoot a deer over it and planting apple trees for deer to have food. One is baiting, the other is providing habitat. Surely sportsmen can see the difference in that.