Soil pH in Yankton, SD: Lime or Sulfur?

Typical topsoil pH in Yankton, SD

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

What Yankton 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 7, you can skip lime and sulfur for lawn (cool-season grass), vegetable garden, tomatoes, roses.

How mixed the soil is

Of the 331,847 surveyed acres in Yankton, SD, 66% are near neutral (6.5-7.3), 31% are alkaline (above 7.3), 3% are moderately acidic (5.5-6.5). Mapped soils run from pH 6 to 8.2, a spread of 2.2 units across 371 soil components. 66% 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 25.9% clay and 3.46% 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. 37% of mapped components carry free carbonate (lime already in the ground), enough that sulfur gets neutralised before it does much.

Yankton against the rest of South Dakota

pH 7 is right at the South Dakota median of 6.99. 34 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: Bon Homme (6.97), Corson (6.97), Codington (6.99), Deuel (6.99), Bennett (7.01), Brookings (7.01), Grant (7.01), Brown (7.02).

The range in South Dakota runs from Lawrence at 6.49 to Jones at 7.47; Yankton sits 52% of the way up.