Grid soil sampling gained popularity in the mid-1990’s as a practice designed to identify the variability of soil test levels within fields. The use of differentially corrected GPS allows users to navigate to, and log known soil sampling positions with a repeatable accuracy of 3-10 ft. Most would use a grid-point sampling technique which involves taking six to eight cores from an area having a ten ft. radius on a sampling density typically ranging between one (~200 ft.) and 2.5 acres (~300 ft.). Variable-rate fertilization maps can then created by interpolation methods from the known soil test values at the individual sample point. Grid-point sampling is a relatively expensive practice compared to conventional sampling for single-rate application because of the time required to take the samples, the additional cost of analysis, and the expense associated with the necessary specialized equipment (laptop computer, DGPS, software, etc.). However, grid-point sampling will provide a detailed layer of information on soil test variability which some growers used to improve their management of P and K fertilizer, lime, and other nutrients.