I planted a honeycrisp apple tree a little over a month ago. Not knowing what I was doing, I dug out the clay soil and replaced most of it with compost for planting. The tree was good for a few weeks but the past couple weeks the leaves have been turning brown and crispy. I have been watering about twice a week. Is it fertilizer burn? The nectarine tree I planted next to it seems fine although hasn't seemed to grow at all. Appreciate any advice from you guys.

Heres the pics:
http://imgur.com/a/bJf6t

Here is a link that might be useful: http://imgur.com/a/bJf6t