Zone Forge reads your Hawaii soil test in Hawaii's own calibrated language — the critical levels and rate logic come straight from Hawaii — UH-Manoa CTAHR Agricultural Diagnostic Service Center, not a national average.
Published source: Hawaii — UH-Manoa CTAHR Agricultural Diagnostic Service Center
Hawaii — UH-Manoa CTAHR Agricultural Diagnostic Service Center. Zone Forge cites the publication on every recommendation.
Yes — the Hawaii soil-test recommendation calculator is free and needs no signup. Enter your lab values for source-cited P, K and lime guidance.
Zone Forge reads every Hawaii soil test in its own state's language, then builds source-cited fertilizer and lime recommendations and full variable-rate prescriptions. See the science →