Soil pH in Spink, SD: Lime or Sulfur?

Typical topsoil pH in Spink, SD

Typical topsoil in Spink, SD is pH 6.89, already right for vegetable garden (6-7). Test before adding anything.

What Spink needs, by plant

• Already in range: lawn (cool-season grass), vegetable garden, roses.
• Just outside, test first: tomatoes (off by 0.1).
• Sulfur: potatoes 3.2 lb/100 sq ft over 2 applications; strawberries 2.1 lb/100 sq ft over 2 applications; blueberries 4.4 lb/100 sq ft over 3 applications; azaleas and rhododendrons 3.7 lb/100 sq ft over 2 applications; blue hydrangeas 3.7 lb/100 sq ft over 2 applications; pink hydrangeas 1.4 lb/100 sq ft.

What to do next

If your test lands near 6.89, you can skip lime and sulfur for lawn (cool-season grass), vegetable garden, tomatoes, roses.

How mixed the soil is

Of the 959,854 surveyed acres in Spink, SD, 88% are near neutral (6.5-7.3), 12% are alkaline (above 7.3). Mapped soils run from pH 6.1 to 8.2, a spread of 2.1 units across 1,432 soil components. 88% 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 23.7% clay and 4.13% 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. 12% of mapped components carry free carbonate (lime already in the ground).

Spink against the rest of South Dakota

pH 6.89 is 0.1 below the South Dakota median of 6.99. 19 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: Walworth (6.85), Hyde (6.87), McCook (6.89), Minnehaha (6.89), Brule (6.9), Buffalo (6.9), Davison (6.91), Kingsbury (6.91).

The range in South Dakota runs from Lawrence at 6.49 to Jones at 7.47; Spink sits 41% of the way up.