It is difficult to say but I have seen very similar damage on trees with large root balls over 100 pounds that were poorly handled somewhere between the grower and your home.
For example, if the trunk of the tree bounced up and down on top rim of a pickup bed or trailer gate it would kill parts of the trunk. The tree would look fine but have severe internal damage. The tree would wall off the damaged areas. Due to the size of the wound and the position so low on the trunk this tree has a significant probability of failing due to wind snapping it in two at the damaged area.
I also note that unless this was planted as a bare root tree the stake is way too close to the root ball. The suggested guidelines are twelve to eighteen inches away from the trunk and using at least two stakes. Damage could have been done to large roots near the trunk with the stake.
The other way that produces damage like this is by staking the plant and securing it with wire. This produces a ring of damaged tissue where the trunk is secured and can, if left on long enough, garrote the tree. However, this kind of damage normally happens higher up the tree.
Here is a link to proper planting and staking practices.
There appears to be a bulge at the soil line that indicates that the tree could be grafted. There is nothing wrong with grafting and growers use this technique extensively to get slower growing cultivars to grow faster. Before you buy a tree try and find out if it is grafted. If the retailer cannot tell you maybe you are shopping at the wrong place.
This site has these recommendations for planting grafted trees:
- When placing the tree in the planting hole orientate the bowed area of the graft to ward the prevailing wind.
- When planting place the tree in the planting hole and hold it so that the graft is at least six inches above the soil line. Now add
subsoil (if present) to a level that allows the graft to be at least 6
inches above the soil line. Next add the top soil to the hole
- Don't tie a tree tightly to the stake. A tree must flex in the wind for strong roots and trunk.
- The stake should be 6 - 12 inches from the trunk. Tie the tree with a figure 8 loop around the tree and stake. Old garden hose with a wire
through it is ideal.
- Tie low. Trees have a stiff lower portion and a more limber upper portion. Shake the tree and find the transition area between the stiff
and limber portion. Tie 6 inches above the point where the trunk
begins to flex the most.
Edit: One way to find out more is to cut away parts of the bark that are dead. Examine what's underneath. If you see wet, moldy tissue with then this might indicate a bacterial issue. If the bark underneath is normal tissue growing over the wound area then it is definitely a mechanical injury.