Soil pH in Iron, UT: Lime or Sulfur?

Typical topsoil pH in Iron, UT

Typical topsoil in Iron, UT is pH 7.89 and calcareous, so sulfur won't lower it for long. For vegetable garden, choose alkaline-tolerant varieties and add compost rather than fighting the soil.

What Iron needs, by plant

• Beds or pots instead: lawn (cool-season grass), vegetable garden, tomatoes, potatoes, strawberries, roses, blueberries, azaleas and rhododendrons, blue hydrangeas, pink hydrangeas.

What to do next

If your test confirms pH near 7.89, consider raised beds for anything acid-loving; with 50% of soils here carrying free lime, sulfur will not hold.

How mixed the soil is

Of the 1,492,219 surveyed acres in Iron, UT, 79% are alkaline (above 7.3), 21% are near neutral (6.5-7.3), 1% are moderately acidic (5.5-6.5). Mapped soils run from pH 5.8 to 10.1, a spread of 4.3 units across 280 soil components. 79% of the land falls in one class, so the county figure is a fair first guess for most yards here.

Clay, organic matter and rates

Topsoil here averages 20.5% clay and 2.06% organic matter, which this site treats as loam. Moving it one pH unit takes about 7 lb of lime or 2.3 lb of sulfur per 100 sq ft. 50% of mapped components carry free carbonate (lime already in the ground), enough that sulfur gets neutralised before it does much.

Iron against the rest of Utah

pH 7.89 is 0.06 below the Utah median of 7.95. 13 of 29 Utah counties have more acidic topsoil. Nationally it is more alkaline than the US county median of 6.05.

Closest in pH within the state: Washington (7.79), Rich (7.83), Carbon (7.84), Utah (7.84), Sanpete (7.95), Beaver (7.98), San Juan (8.03), Duchesne (8.05).

The range in Utah runs from Morgan at 6.66 to Millard at 8.44; Iron sits 69% of the way up.