Nobody really likes to hear the phrase “that depends” in response to a question. Quite frequently I am asked “How much lime will it take to move my soil pH by a point?” The answer unfortunately is “That depends!”. You see, there are several factors involved which come into play. Soil temperature and amount of rainfall will determine how quickly the lime will react with the soil. Additionally, soil acidity has two components, active acidity and buffer capacity. Buffer capacity is the soil’s ability to “resist” change of pH and is a function of the soil type. When a lab analyzes a soil sample for pH they will also determine the soil CEC. A high CEC (cation exchange capacity) indicates the soil will have more “reserve” acidity and be more resistant to change in pH. Soils high in clay content will exhibit this characteristic. For that reason, high clay soils may require a higher initial application rate, or more frequent additions, such as a spring and fall application.