Delaware · Soil test

Delaware soil-test fertilizer recommendations

Zone Forge reads your Delaware soil test in Delaware's own calibrated language — the critical levels and rate logic come straight from Delaware — UD Cooperative Extension Soil Testing Program (Mehlich-3 / UD-FIV), not a national average. Lime has its own live calculator for Delaware with method-specific lab inputs.

Critical soil-test levels

  • P: critical 25 FIV (Mehlich-3 reported as UD-FIV)
  • K: critical 25 FIV (Mehlich-3 reported as UD-FIV)
  • Mg: critical 40 FIV (Mehlich-3 reported as UD-FIV)

Per Delaware — UD Cooperative Extension Soil Testing Program (Mehlich-3 / UD-FIV) — below the critical level, a yield response to the added nutrient is expected.

Crops covered

Delaware — UD Cooperative Extension Soil Testing Program (Mehlich-3 / UD-FIV) rates these crops in Delaware:

AlfalfaBarleyCornCorn silageGrass / forageGrass hayOatsPastureRyeSorghumSorghum silageSoybeansWheat

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

Published source: Delaware — UD Cooperative Extension Soil Testing Program (Mehlich-3 / UD-FIV)

Frequently asked

What soil-test method does Delaware use?

Delaware — UD Cooperative Extension Soil Testing Program (Mehlich-3 / UD-FIV). Zone Forge cites the publication on every recommendation.

Is the Delaware soil-test calculator free?

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

Can Zone Forge calculate a Delaware lime rate?

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

Zone Forge reads every Delaware 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 →