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.

See Utah recommendations → Utah lime guide

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.

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, K and lime guidance.

Zone Forge reads every Utah soil test in its own state's language, then builds source-cited fertilizer and lime recommendations and full variable-rate prescriptions. See the science →