Potato plants are very inefficient in their ability to utilize soil phosphorus (P) on some soils (Kelling et al., 1997). The optimum soil test P category for potato is more than three times greater than for other crops (Laboski et al., 2006). Being a high value crop, potato growers generally tend to apply more P fertilizer than recommended because it is inexpensive insurance if a yield response to applied P would occur. State nutrient management regulation requires growers to write and follow a nutrient management plan. This regulation also requires that nutrient application rates should conform to University of Wisconsin Extension (UWEX) guidelines. The potato growers feel that UWEX fertilizer recommendations for P are too low and could potentially reduce potato yield and quality.