One of the most economically important services available to Kentucky farmers is that of soil testing and fertilizer recommendations. Fertilizer purchases on the order of 150 million dollars per year are currently made by farmers in Kentucky. Until about 30 years ago there was no routine, rapid method for analyzing soils to determine fertilizer needs. Since then, as better methods were developed, soil testing laboratories have been set up for routine farmer use. For many years only the soil testing service provided through the University of Kentucky (UK) was readily available to farmers in Kentucky. Even though the University still provides statewide service. Many commercial laboratories have been developed which now also serve the state.
Murdock, Lloyd W. and Hendrick, William, "Corn Yields from Fertilizer Recommendations Made by Some Soil Testing Laboratories Serving Kentucky" (1980). Agronomy Notes. 90.