Zone Forge reads your Washington soil test in Washington's own calibrated language — the critical levels and rate logic come straight from WSU Extension — East/West Cascade nutrient + Inland NW lime (combined source), not a national average. Lime has its own live calculator for Washington with method-specific lab inputs.
WSU Extension — East/West Cascade nutrient + Inland NW lime (combined source) rates these crops in Washington:
More crops via alternate guides selectable in Washington: PNW 615 — Nutrient Management for Field Corn Silage and Grain in the Inland Pacific Northwest, EM 9140 — Green Pea Nutrient Management for the Inland Northwest, East of the Cascades, EM 9224 — Nutrient Management for Pastures: Western Oregon and Western Washington.
Published source: WSU Extension — East/West Cascade nutrient + Inland NW lime (combined source)
WSU Extension — East/West Cascade nutrient + Inland NW lime (combined source). Zone Forge cites the publication on every recommendation.
Yes — the Washington soil-test recommendation calculator is free and needs no signup. Enter your lab values for source-cited P and K; Washington's live lime calculator is available separately with its own required lab inputs.
Yes — the free soil-test calculator covers source-cited P and K. Washington also has a live lime calculator on Zone Forge that uses the state's published method. Open the Washington lime guide or lime calculator for tons of CaCO3-equivalent per acre.
Zone Forge reads every Washington 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 →