Soil pH in Clark, IN: Lime or Sulfur?

Typical topsoil pH in Clark, IN

Typical topsoil in Clark, IN is pH 5.76, just outside the 6-7 range for vegetable garden. Test first; it may need nothing.

What Clark needs, by plant

• Already in range: potatoes, strawberries, azaleas and rhododendrons.
• Just outside, test first: lawn (cool-season grass) (off by 0.2), vegetable garden (off by 0.2), roses (off by 0.2), pink hydrangeas (off by 0.2).
• Lime: tomatoes 4.9 lb/100 sq ft.
• Sulfur: blueberries 1.8 lb/100 sq ft; blue hydrangeas 1.2 lb/100 sq ft.

What to do next

If your test lands near 5.76, you can skip lime and sulfur for lawn (cool-season grass), vegetable garden, potatoes, strawberries, roses, azaleas and rhododendrons, pink hydrangeas.

How mixed the soil is

Of the 214,604 surveyed acres in Clark, IN, 82% are moderately acidic (5.5-6.5), 15% are strongly acidic (below 5.5), 2% are near neutral (6.5-7.3). Mapped soils run from pH 4.3 to 7.5, a spread of 3.2 units across 593 soil components. 82% 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 17.8% clay and 2.09% 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. 0% of mapped components carry free carbonate (lime already in the ground).

Clark against the rest of Indiana

pH 5.76 is 0.59 below the Indiana median of 6.35. 7 of 92 Indiana counties have more acidic topsoil. Nationally it is more acidic than the US county median of 6.05.

Closest in pH within the state: Crawford (5.62), Martin (5.66), Dubois (5.69), Floyd (5.7), Scott (5.79), Orange (5.8), Washington (5.82), Lawrence (5.84).

The range in Indiana runs from Brown at 4.97 to Hamilton at 6.74; Clark sits 45% of the way up.