Ok, much clearer pictuer of your problem now, good photos. If it were me I would decompact the soil out as far as possible from the stem of the tree. Remember the fine absorbing roots extend much much further than you'd expect. Any ISA certified arborist worth their salt will be able to do this, its quick and inexpensive.
Vert mulch.JPG
There's no shot of the canopy so assuming there are no indicators of blight, rust, curl etc... and the
only issue is the bark damage. over the decompacted soil and root system I would spread a well composted mulch (ideally from woodchips of holly branches) over the entire area making sure you don't touch the stem.
You can go further but of course it adds the $$'s, get a soil food web analysis and from that obtain an appropriate compost tea which is applied as a drench to the soil and a foliar spray.
We've used decompaction and mulching for many clients with tremendous results, we also provide enhanced environments for the soil micro-organisms which in turn result in visible improvements in tree health and vigour.
If you don't want the expense of the soil food web analysis etc.. apply fish emulsion, seaweed extract and humic acid ove the wood chip mulch
We don't fertilize established trees with Nitrogen fertilizers, all you produce is a Nitrogen junky or salad on a stick for hundreds of critters
SF