I use soil tests through coop extention (NY version, but basically the same). I rely on their field crop guys for extra assistance when neccessary.
One thing to remember is that their reccomendations are based on best economic return. Another words they use the concept of shrinking returns in growth relative to costs of lime, fertilizer and application with heavier applications. In many cases, especially with smaller plots, hunter/managers might be willing to go past those points to get better growth, especially higher protein levels. Just as long as you stay below toxic levels.