Iron bars planted with the tree?

[Drip]

A friend showed me two Shumard Red Oaks planted at the same time. One had four 3-foot iron bars driven in around the root ball, giving it trace amounts of iron each time it rained. The tree with the iron around it is a much bigger, healthier tree.

Bad idea? Good idea? Old wives tale? Lazy?

[sandih]

Surely there's a better why to provide iron to a tree. What happens when the tree grows and the bar becomes impeded in the tree?