v2.4 (2026-08-23) · University of Florida / IFAS Extension Soil Testing Laboratory (ESTL) nutrient recommendations (SS163/SL129, rev. 10/2021). UF/IFAS uses Mehlich-3 extraction statewide. Florida-specific calibration: P critical is 25 ppm M3 (LOWER than Penn State's 30) reflecting Florida's sandy low-buffering soils. STRICT sufficiency philosophy — published Low/Medium/High bracket rates (NO buildup); 0 fertilizer recommended above 'High' rating. P2O5/K2O are served by the 'florida_ifas_lookup' state-method handler that reads SS163's published L/M/H bracket table directly. In-app rates cover the staged IFAS agronomic, forage, and vegetable crops (47 pickable crops including corn, peanut, cotton, soybean, sugarcane, and vegetables). Lime is handled via the Coastal Plain Adams-Evans source (separate); this source covers nutrient recommendations only.
State extension method. Zone Forge computes this source's supported nutrient rates in-app and cites the published method.
Yes — Zone Forge's calculators are free and need no signup. This page shows the states and crops UF/IFAS — Standardized Fertilization Recommendations for Agronomic Crops covers so you can verify the source behind your recommendation.
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