Soil pH in Hamlin, SD: Lime or Sulfur?

Typical topsoil pH in Hamlin, SD

Typical topsoil in Hamlin, SD is pH 6.95, already right for vegetable garden (6-7). Test before adding anything.

What Hamlin needs, by plant

• Already in range: lawn (cool-season grass), vegetable garden, roses.
• Just outside, test first: tomatoes (off by 0.2).
• Beds or pots instead: potatoes, strawberries, blueberries, azaleas and rhododendrons, blue hydrangeas, pink hydrangeas.

What to do next

If your test lands near 6.95, you can skip lime and sulfur for lawn (cool-season grass), vegetable garden, tomatoes, roses.

How mixed the soil is

Of the 323,546 surveyed acres in Hamlin, SD, 50% are near neutral (6.5-7.3), 28% are alkaline (above 7.3), 22% are moderately acidic (5.5-6.5). Mapped soils run from pH 6.4 to 8.2, a spread of 1.8 units across 480 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 27.2% clay and 3.85% 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. 34% of mapped components carry free carbonate (lime already in the ground), enough that sulfur gets neutralised before it does much.

Hamlin against the rest of South Dakota

pH 6.95 is right at the South Dakota median of 6.99. 29 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: Kingsbury (6.91), Jerauld (6.93), Pennington (6.94), Todd (6.94), Bon Homme (6.97), Corson (6.97), Codington (6.99), Deuel (6.99).

The range in South Dakota runs from Lawrence at 6.49 to Jones at 7.47; Hamlin sits 47% of the way up.