Soil pH in Lawrence, SD: Lime or Sulfur?

Typical topsoil pH in Lawrence, SD

Typical topsoil in Lawrence, SD is pH 6.49, already right for vegetable garden (6-7). Test before adding anything.

What Lawrence needs, by plant

• Already in range: lawn (cool-season grass), vegetable garden, tomatoes, strawberries, roses, pink hydrangeas.
• Sulfur: potatoes 2.3 lb/100 sq ft over 2 applications; blueberries 3.5 lb/100 sq ft over 2 applications; azaleas and rhododendrons 2.8 lb/100 sq ft over 2 applications; blue hydrangeas 2.8 lb/100 sq ft over 2 applications.

What to do next

If your test lands near 6.49, you can skip lime and sulfur for lawn (cool-season grass), vegetable garden, tomatoes, strawberries, roses, pink hydrangeas.

How mixed the soil is

Of the 511,601 surveyed acres in Lawrence, SD, 46% are moderately acidic (5.5-6.5), 38% are near neutral (6.5-7.3), 14% are alkaline (above 7.3), 3% are strongly acidic (below 5.5). Mapped soils run from pH 4.5 to 8.5, a spread of 4 units across 1,090 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 18.7% clay and 3.6% 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. 17% of mapped components carry free carbonate (lime already in the ground).

Lawrence against the rest of South Dakota

pH 6.49 is 0.5 below the South Dakota median of 6.99. 0 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: Sully (6.64), Lake (6.71), Douglas (6.76), Lincoln (6.76).