Zone Forge reads your South Dakota soil test in South Dakota's own calibrated language — the critical levels and rate logic come straight from South Dakota - SDSU Extension Fertilizer Recommendations (EC750 lineage + S-0003-23 Corn / S-0004-22 Soybean / S-0005-11 Wheat), not a national average.
Published source: South Dakota - SDSU Extension Fertilizer Recommendations (EC750 lineage + S-0003-23 Corn / S-0004-22 Soybean / S-0005-11 Wheat)
South Dakota - SDSU Extension Fertilizer Recommendations (EC750 lineage + S-0003-23 Corn / S-0004-22 Soybean / S-0005-11 Wheat). Zone Forge cites the publication on every recommendation.
Yes — the South Dakota 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 South Dakota soil test in its own state's language, then builds source-cited fertilizer and lime recommendations and full variable-rate prescriptions. See the science →