Q: Since I have used a professional service to feed and oil my shrubs the Alberta Spruce experience winter kill on the south side of the plant.
They are 10 years old and didn't experience problems before. Do you think there is a relationship?
As for fertilization, unless the plants were over-fertilized, which is unlikely but not impossible, there should be no problem from this either. But from your description of the damage being only on the south side, I would not suspect either of these as the cause without further investigation.
I would recommend you consider applying an anti-transpirant in fall if you're experiencing winter damage.
Anti-transpirants reduce the amount of moisture the needles lose during the winter, which helps reduce winter kill or burn. It also reduces injury from salt spray landing on the plant.
If the south side of your Alberta spruce faces an area that gets salted, it's possible the salty mist has burned the plant.