Soil pH in Sumter, AL: Lime or Sulfur?

Typical topsoil pH in Sumter, AL

Typical topsoil in Sumter, AL is pH 5.55, too acidic for vegetable garden. Expect roughly 7 lb of lime per 100 sq ft, but only after a soil test confirms it.

What Sumter needs, by plant

• Already in range: potatoes, strawberries, azaleas and rhododendrons.
• Just outside, test first: blueberries (off by 0), blue hydrangeas (off by 0).
• Lime: lawn (cool-season grass) 7 lb/100 sq ft over 2 applications; vegetable garden 7 lb/100 sq ft over 2 applications; tomatoes 7 lb/100 sq ft over 2 applications; roses 7 lb/100 sq ft over 2 applications; pink hydrangeas 4.9 lb/100 sq ft.

What to do next

If your test confirms pH near 5.55, spread about 70 lb of ground limestone per 1,000 sq ft of vegetable bed in 2 doses, ideally in fall.

How mixed the soil is

Of the 418,207 surveyed acres in Sumter, AL, 74% are strongly acidic (below 5.5), 20% are alkaline (above 7.3), 6% are moderately acidic (5.5-6.5). Mapped soils run from pH 4.5 to 8.1, a spread of 3.6 units across 38 soil components. 74% 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 25.6% clay and 1.49% 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).

Sumter against the rest of Alabama

pH 5.55 is 0.4 above the Alabama median of 5.15. 60 of 67 Alabama counties have more acidic topsoil. Nationally it is more acidic than the US county median of 6.05.

Closest in pH within the state: Morgan (5.44), Greene (5.48), Marengo (5.48), Dallas (5.51), Chambers (5.57), Jackson (5.65), Lawrence (5.65), Montgomery (5.71).

The range in Alabama runs from Randolph at 4.89 to Lowndes at 6.25; Sumter sits 49% of the way up.