Welcome to the the board Answerguy - Dan's got it right, he has a lot of knowledge in this area, and we are lucky to have him here.

I have a couple points I'd make:

Trace elements are likely adequate on most soils, and rarley get depleted. The most important elements to consider are Phosphurus (P) Calcium (Ca) and Potassium (K), and Nitrogen (N). These elements CAN and WILL get depleted over time, especially of the plants growing there are harvested.

Interestingly enough, Calcium, is the "unsung" element, and often overlooked. People think "just throw down some fertilizer (N, P,K), and it'll grow better". While this "could" be true, its not usually that simple. Here is a quick run through - on what Calcium does:

All soil tends to become acidic if Calcium levels are, or become low. When Calcium becomes depleted, the acidity causes the roots of the plants to become "less able" to use the other elements in the soil, that the plant needs to grow. This is due to a chemical reaction, that causes the roots nodes to "bind" with inert acidic molecules, rather than essential molecules (N, P, &K). As a result, at some point, it becomes a moot point how much N,P&K are there, the plant cannot use it anyhow! Adding fertilizer at this point does nothing for the plant, and may actually hurt it more because most commercial fertilizers are acidic as well.

Of course, Lime is the key when the soil is or becomes acidic, and by adding calcium in the form of Dolomatic Limestone, nutrients in the soil previously unavailable to the plant are now available for uptake. That is why we often here of Lime being reffered to as "poor man's fertilizer".

Whole topics could be spent on Nitrogen (especially), Potassium, and Phosphorus as well, but I think its KEY to understanding the role soil acidity and calcium, plays in food plot production first. My synopsis above is dreadfully lacking in detail, there is a lot of good information on the net, you should research - when you have a soil test done, it pays to understand these elements, and the relationship between them, and the forage of choice.

Hope I didn't bore you to sleep