Coverage · Source

Colorado — CSU Extension Crop Series Soil fact sheets (Olsen-P + Mehlich-3 dual calibration)

v1.2 (2026-08-23) · CSU Extension Fertilizing Alfalfa (Davis, J.G., Brummer, J.E., Deiss, L.; reviewed May 2025 by Jessica Davis) — Tables 1–5 verbatim. Fertilizing Winter Wheat fact sheet 0.544 (Davis & Westfall, rev. 2014). Fertilizing Corn fact sheet 0.538. Fertilizing Spring-Seeded Small Grains fact sheet 0.534. CSU Soil, Water and Plant Testing Laboratory (Fort Collins) is the primary land-grant lab; private commercial labs (Ward, AgVise, Servi-Tech) commonly used statewide.

State extension method Computes rates in-app
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Crops covered

AlfalfaBarleyCornCorn silageDry beansGrass hayMilletPotatoesSmall grainsSugar beetsWheat

Nutrient source for

CO

Frequently asked

What method does Colorado — CSU Extension Crop Series Soil fact sheets (Olsen-P + Mehlich-3 dual calibration) use?

State extension method. Zone Forge computes this source's supported nutrient rates in-app and cites the published method.

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