Soil pH in Niobrara, WY: Lime or Sulfur?

Typical topsoil pH in Niobrara, WY

Typical topsoil in Niobrara, WY is pH 7.42 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 Niobrara 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 7.42, consider raised beds for anything acid-loving; with 49% of soils here carrying free lime, sulfur will not hold.

How mixed the soil is

Of the 1,497,656 surveyed acres in Niobrara, WY, 51% are alkaline (above 7.3), 48% are near neutral (6.5-7.3), 1% are strongly acidic (below 5.5). Mapped soils run from pH 4.3 to 9.1, a spread of 4.8 units across 357 soil components. No single class covers 60% of the county, so two gardens a few miles apart here can need opposite treatments. Test your own bed.

Clay, organic matter and rates

Topsoil here averages 19.5% clay and 1.76% 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. 49% of mapped components carry free carbonate (lime already in the ground), enough that sulfur gets neutralised before it does much.

Niobrara against the rest of Wyoming

pH 7.42 is 0.08 below the Wyoming median of 7.5. 8 of 23 Wyoming counties have more acidic topsoil. Nationally it is more alkaline than the US county median of 6.05.

Closest in pH within the state: Hot Springs (7.34), Johnson (7.35), Campbell (7.37), Laramie (7.42), Converse (7.5), Weston (7.5), Goshen (7.55), Albany (7.58).

The range in Wyoming runs from Teton at 6.19 to Carbon at 8.31; Niobrara sits 58% of the way up.