Utah · Soil test

Utah soil-test fertilizer recommendations

Zone Forge reads your Utah soil test in Utah's own calibrated language — the critical levels and rate logic come straight from Utah — USU Cooperative Extension (Olsen-P + NaHCO3-K calibration), not a national average. Lime is rarely needed per Utah's alkaline-soil guidance — no automatic rate is invented.

Critical soil-test levels

  • P: critical 10 ppm (Olsen (NaHCO3), 12-inch sample depth)
  • K: critical 100 ppm (NaHCO3-extractable K, 12-inch sample depth)

Per Utah — USU Cooperative Extension (Olsen-P + NaHCO3-K calibration) — below the critical level, a yield response to the added nutrient is expected.

Crops covered

Utah — USU Cooperative Extension (Olsen-P + NaHCO3-K calibration) rates these crops in Utah:

AlfalfaOatsPasturePotatoesSmall grains

Published source: Utah — USU Cooperative Extension (Olsen-P + NaHCO3-K calibration)

Frequently asked

What soil-test method does Utah use?

Utah — USU Cooperative Extension (Olsen-P + NaHCO3-K calibration). Zone Forge cites the publication on every recommendation.

Is the Utah soil-test calculator free?

Yes — the Utah soil-test recommendation calculator is free and needs no signup. Enter your lab values for source-cited P and K. Lime is advisory only here — see the Utah lime guide rather than expecting a numeric calculator rate.

Can Zone Forge calculate a Utah lime rate?

Usually not. Utah is an alkaline-soil region — Zone Forge does not invent an automatic lime rate. Review the cited guidance on the Utah lime guide; if a lab report shows unusually acid soil, confirm with the lab or local Extension before liming.

Zone Forge reads every Utah soil test in its own state's language, then builds source-cited fertilizer and alkaline-soil lime guidance (no automatic rate) and full variable-rate prescriptions. See the science →