Well, obviously, if you've been fertilizing, and the soil test level is dropping, the fertilizer rate is too low - not accounting for drought, etc. So, for year 1 after the new soil tests, I would increase the fertilizer rate - above what was done in the past.

Second, I think I would increase my soil testing frequency. Compared to the price of fertilizer, soil testing is very inexpensive.  So, I would re-test after the 1st year, as a way to verify that the "new" soil test was not an anomoly.  and then soil test every 1 to 2 years and fertilize accordingly, until I was comfortable that I had a new trend that I was satisfied with.

edit: spelling