This tree is about 5-6 years old. It had been looking sick for the last 2-3 years. Last summer it had leaves on the tree, but they were all small and pale yellow. Now as you can see there are few leaves. We have tried iron and fertilizer. We lost another oak in our yard about 3 years ago that was about the same age. Could it be the soil? Is there anything we can try to save it?