Yields are variable across production cotton fields. The yield at any location in the field is a function of the integration of the environment at that location with the genetic potential of the plant. Seed cotton yields and soil samples were collected from many locations along a transact in each of two cotton fields in Mississippi. A significant relationship was found between yield and soil test values of P and K. The same relationship fit data from both locations. In both cases, the relationship between soil test P and yield was negative and the X/yield relationship was positive.