When applying phosphorus to soils it is important to know how much the soil test P changes with the addition of various rates. Soils are different in how they respond to varying rates of application, and only limited information is available for Kentucky soils.
Thom, William O. and Dollarhide, James E., "Phosphorus Soil Test Change Following the Addition of Phosphorus Fertilizer to 16 Kentucky Soils" (2002). Agronomy Notes. 11.