Soil pH in Dewey, SD: Lime or Sulfur?

Typical topsoil pH in Dewey, SD

Typical topsoil in Dewey, SD is pH 7.28 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 Dewey 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 7.28, consider raised beds for anything acid-loving; with 57% of soils here carrying free lime, sulfur will not hold.

How mixed the soil is

Of the 1,458,201 surveyed acres in Dewey, SD, 58% are alkaline (above 7.3), 39% are near neutral (6.5-7.3), 4% are moderately acidic (5.5-6.5). Mapped soils run from pH 6 to 8.8, a spread of 2.8 units across 417 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 41.3% clay and 2.76% organic matter, which this site treats as clay. Moving it one pH unit takes about 11.5 lb of lime or 3.4 lb of sulfur per 100 sq ft. 57% of mapped components carry free carbonate (lime already in the ground), enough that sulfur gets neutralised before it does much.

Dewey against the rest of South Dakota

pH 7.28 is 0.29 above the South Dakota median of 6.99. 58 of 66 South Dakota counties have more acidic topsoil. Nationally it is more alkaline than the US county median of 6.05.

Closest in pH within the state: Campbell (7.2), Union (7.2), Butte (7.23), Custer (7.23), Lyman (7.28), Jackson (7.32), Stanley (7.38), Oglala Lakota (7.39).

The range in South Dakota runs from Lawrence at 6.49 to Jones at 7.47; Dewey sits 81% of the way up.