Pennsylvania's land-grant extension publishes a method — not a one-size-fits-all rate. Penn State AASL Mehlich Buffer Acidity method (meq/100 g). Live inputs: Mehlich Buffer acidity (meq/100 g) and crop pH goal — not SMP buffer pH alone. Enter the required soil-test values in the free calculator for tons of CaCO₃-equivalent per acre, ECCE-adjusted, with the citation.
Published source: Penn State Agronomy Guide
It depends on Mehlich Buffer exchangeable acidity (meq/100 g on the AASL report as "Acidity") and your crop's pH-goal column — Penn State retired Adams-Evans buffer-pH for this method. Penn State AASL Mehlich Buffer Acidity method (meq/100 g). Enter acidity and crop goal in the free Zone Forge lime calculator for tons of CaCO3-equivalent per acre, with the citation.
Penn State AASL drives lime from Mehlich Buffer / exchangeable acidity (meq/100 g), looked up at the published pH-goal column for the crop. Penn State AASL Mehlich Buffer Acidity method (meq/100 g). Source: Penn State Agronomy Guide.
Zone Forge computes Pennsylvania lime from that state's published land-grant method (Mehlich Buffer exchangeable acidity (meq/100 g) and the crop's published pH-goal column) — lime calculator, soil-test fertilizer, and full variable-rate prescriptions. See the science →