Thanks for writing. When a plant's leaves are pale, it usually means the tree isn't getting the nutrients it needs. So your best course of action is to have a soil test done. Contact your local cooperative extension office for help in getting this done.
The results of your soil test will tell you how much of what products you need to add to get your soil back in shape for your maple. Learn more about testing your soil here: http://www.bhg.com/gardening/yard/soil/do-a-soil-test/