Soil pH in Marion, IN: Lime or Sulfur?

Typical topsoil pH in Marion, IN

Typical topsoil in Marion, IN is pH 6.71, already right for vegetable garden (6-7). Test before adding anything.

What Marion needs, by plant

• Already in range: lawn (cool-season grass), vegetable garden, tomatoes, roses.
• Just outside, test first: strawberries (off by 0.2), pink hydrangeas (off by 0.2).
• Sulfur: potatoes 2.8 lb/100 sq ft over 2 applications; blueberries 3.9 lb/100 sq ft over 2 applications; azaleas and rhododendrons 3.5 lb/100 sq ft over 2 applications; blue hydrangeas 3.5 lb/100 sq ft over 2 applications.

What to do next

If your test lands near 6.71, 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 166,731 surveyed acres in Marion, IN, 81% are near neutral (6.5-7.3), 17% are moderately acidic (5.5-6.5), 1% are strongly acidic (below 5.5). Mapped soils run from pH 5.2 to 7.9, a spread of 2.7 units across 196 soil components. 81% 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 20% clay and 2.74% 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. 9% of mapped components carry free carbonate (lime already in the ground).

Marion against the rest of Indiana

pH 6.71 is 0.36 above the Indiana median of 6.35. 90 of 92 Indiana counties have more acidic topsoil. Nationally it is more alkaline than the US county median of 6.05.

Closest in pH within the state: Benton (6.61), Madison (6.63), Johnson (6.67), Hendricks (6.69), Hamilton (6.74).

The range in Indiana runs from Brown at 4.97 to Hamilton at 6.74; Marion sits 98% of the way up.