Soil pH in Simpson, MS: Lime or Sulfur?

Typical topsoil pH in Simpson, MS

Typical topsoil in Simpson, MS is pH 5.06, too acidic for vegetable garden. Expect roughly 9.8 lb of lime per 100 sq ft, but only after a soil test confirms it.

What Simpson needs, by plant

• Already in range: potatoes, blueberries, azaleas and rhododendrons, blue hydrangeas.
• Lime: lawn (cool-season grass) 9.8 lb/100 sq ft over 2 applications; vegetable garden 9.8 lb/100 sq ft over 2 applications; tomatoes 9.8 lb/100 sq ft over 2 applications; strawberries 6.3 lb/100 sq ft over 2 applications; roses 9.8 lb/100 sq ft over 2 applications; pink hydrangeas 8.4 lb/100 sq ft over 2 applications.

What to do next

If your test confirms pH near 5.06, spread about 98 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 354,712 surveyed acres in Simpson, MS, 92% are strongly acidic (below 5.5), 7% are moderately acidic (5.5-6.5), 1% are near neutral (6.5-7.3). Mapped soils run from pH 4.5 to 6.8, a spread of 2.3 units across 107 soil components. 92% 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 11.6% clay and 1.53% 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. None of the mapped components carry free carbonate.

Simpson against the rest of Mississippi

pH 5.06 is 0.09 below the Mississippi median of 5.15. 21 of 82 Mississippi counties have more acidic topsoil. Nationally it is more acidic than the US county median of 6.05.

Closest in pH within the state: Jackson (5.06), Perry (5.06), Rankin (5.06), Scott (5.06), Calhoun (5.09), Clarke (5.09), Lawrence (5.09), Tippah (5.09).

The range in Mississippi runs from Hancock at 4.85 to Issaquena at 6.73; Simpson sits 11% of the way up.