Pennsylvania · Soil test

Pennsylvania soil-test fertilizer recommendations

Zone Forge reads your Pennsylvania soil test in Pennsylvania's own calibrated language — the critical levels and rate logic come straight from Penn State Agronomy Guide, not a national average. Lime has its own live calculator for Pennsylvania with method-specific lab inputs.

Critical soil-test levels

  • P: critical 30 ppm (Mehlich-3)
  • K: critical 100 ppm (Mehlich-3)
  • Mg: critical 100 ppm (Mehlich-3)

Per Penn State Agronomy Guide — below the critical level, a yield response to the added nutrient is expected.

Crops covered

Penn State Agronomy Guide rates these crops in Pennsylvania:

AlfalfaBarleyCornCorn silageGrass hayOatsRyeSoybeansWheat

More crops via alternate guides selectable in Pennsylvania: Mid-Atlantic Commercial Vegetable Production Recommendations 2026/2027.

Published source: Penn State Agronomy Guide

Frequently asked

What soil-test method does Pennsylvania use?

Penn State Agronomy Guide. Zone Forge cites the publication on every recommendation.

Is the Pennsylvania soil-test calculator free?

Yes — the Pennsylvania soil-test recommendation calculator is free and needs no signup. Enter your lab values for source-cited P and K; Pennsylvania's live lime calculator is available separately with its own required lab inputs.

Can Zone Forge calculate a Pennsylvania lime rate?

Yes — the free soil-test calculator covers source-cited P and K. Pennsylvania also has a live lime calculator on Zone Forge that uses the state's published method. Open the Pennsylvania lime guide or lime calculator for tons of CaCO3-equivalent per acre.

Zone Forge reads every Pennsylvania soil test in its own state's language, then builds source-cited fertilizer and a live lime calculator and full variable-rate prescriptions. See the science →