Soil pH in Monroe, MS: Lime or Sulfur?

Typical topsoil pH in Monroe, MS

Typical topsoil in Monroe, MS is pH 5.36, too acidic for vegetable garden. Expect roughly 7.7 lb of lime per 100 sq ft, but only after a soil test confirms it.

What Monroe needs, by plant

• Already in range: potatoes, blueberries, azaleas and rhododendrons, blue hydrangeas.
• Just outside, test first: strawberries (off by 0.1).
• Lime: lawn (cool-season grass) 7.7 lb/100 sq ft over 2 applications; vegetable garden 7.7 lb/100 sq ft over 2 applications; tomatoes 7.7 lb/100 sq ft over 2 applications; roses 7.7 lb/100 sq ft over 2 applications; pink hydrangeas 6.3 lb/100 sq ft over 2 applications.

What to do next

If your test confirms pH near 5.36, spread about 77 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 475,223 surveyed acres in Monroe, MS, 80% are strongly acidic (below 5.5), 10% are near neutral (6.5-7.3), 7% are alkaline (above 7.3), 3% are moderately acidic (5.5-6.5). Mapped soils run from pH 4.5 to 7.5, a spread of 3 units across 153 soil components. 80% 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 1.91% 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. 5% of mapped components carry free carbonate (lime already in the ground).

Monroe against the rest of Mississippi

pH 5.36 is 0.21 above the Mississippi median of 5.15. 56 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: Lafayette (5.25), Madison (5.25), Pontotoc (5.28), Tate (5.32), Holmes (5.4), Oktibbeha (5.4), Claiborne (5.43), Leflore (5.44).

The range in Mississippi runs from Hancock at 4.85 to Issaquena at 6.73; Monroe sits 27% of the way up.