To date, site -specific soil test data are commonly used to create variable rate nutrient application maps. Phosphorus (P), potassium (K), and lime are among the inputs varied. Placing nutrients and liming materials more precisely within the field has brought value to site – specific soil test data. However, once a particular data set is replaced with more recent results, it is often perceived that the older set of data no longer has any value. To the contrary, historical soil test data have much to offer.