Oklahoma's land-grant extension publishes a method — not a one-size-fits-all rate. Combined source v2.0 (2026-05-27): lime block (Sikora Buffer Index, wheat target pH 5.5) unchanged from v1.0 + added PSS-2225 nutrient block (Mehlich-3 STI × Percent Sufficiency for 10+ crops). Live calculator uses this state's published method and citation. Enter the required soil-test values in the free calculator for tons of CaCO₃-equivalent per acre, ECCE-adjusted, with the citation.
Central + eastern OK acidifies. Panhandle and Western OK calcareous. OSU publishes a separate wheat-specific target-pH column.
Published source: Oklahoma — OSU SWFAL (PSS-2225) combined lime + nutrient source
It depends on the inputs Oklahoma's land-grant method publishes — not a single national number. Combined source v2.0 (2026-05-27): lime block (Sikora Buffer Index, wheat target pH 5.5) unchanged from v1.0 + added PSS-2225 nutrient block (Mehlich-3 STI × Percent Sufficiency for 10+ crops). Enter your values in the free Zone Forge lime calculator for tons of CaCO3-equivalent per acre, with the citation.
Combined source v2.0 (2026-05-27): lime block (Sikora Buffer Index, wheat target pH 5.5) unchanged from v1.0 + added PSS-2225 nutrient block (Mehlich-3 STI × Percent Sufficiency for 10+ crops). Source: see the calculator citation. Source: Oklahoma — OSU SWFAL (PSS-2225) combined lime + nutrient source.
Zone Forge computes Oklahoma lime from that state's published land-grant method (the lab values required by this state's published method) — lime calculator, soil-test fertilizer, and full variable-rate prescriptions. See the science →