Zone Forge reads your California soil test in California's own calibrated language — the critical levels and rate logic come straight from California — UC ANR / CDFA-FREP / UC Davis Nutrient Management (Olsen-P calibration + commodity manuals), not a national average. Lime has its own live calculator for California with method-specific lab inputs.
California — UC ANR / CDFA-FREP / UC Davis Nutrient Management (Olsen-P calibration + commodity manuals) rates these crops in California:
Published source: California — UC ANR / CDFA-FREP / UC Davis Nutrient Management (Olsen-P calibration + commodity manuals)
California — UC ANR / CDFA-FREP / UC Davis Nutrient Management (Olsen-P calibration + commodity manuals). Zone Forge cites the publication on every recommendation.
Yes — the California soil-test recommendation calculator is free and needs no signup. Enter your lab values for source-cited P and K; California'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. California also has a live lime calculator on Zone Forge that uses the state's published method. Open the California lime guide or lime calculator for tons of CaCO3-equivalent per acre.
Zone Forge reads every California 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 →