Growers who were early innovators with GPS related technologies, have now collected 5+ years of data and are asking, “Where’s the value”. To answer the question for soil sampling systems it is important to take a step back and look at how we arrived to this point. Soil sampling and testing is not a new technology. With the introduction of commercial fertilizers there was a need to differentiate between potentially responsive and non-responsive sites, primarily for phosphorus and potassium. The result was a concentrated effort on the part of our land-grant institutions to run field studies designed to correlate crop response from fertilizer applications against soil test values derived from various extracting solutions and laboratory procedures. Refinement of these initial correlation studies have continued to this date to not only define responsiveness of sites, but also to calibrate soil test values against the application rate of nutrients necessary to achieve optimum economic yield. This effort has been partially successful. Soil testing does a very good job of indicating the probability of response and tracking soil fertility status over time. Soil testing also provides good information on long-term yield response when averaged over a number of years. However efforts to develop a soil test and sampling procedure that will provide a prediction of the optimum fertilizer rate for a specific field and year has been only partially successful.