Soil pH in Coal, OK: Lime or Sulfur?

Typical topsoil pH in Coal, OK

Typical topsoil in Coal, OK is pH 5.81, just outside the 6-7 range for vegetable garden. Test first; it may need nothing.

What Coal 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 1.4 lb/100 sq ft.

What to do next

If your test lands near 5.81, 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 317,935 surveyed acres in Coal, OK, 87% are moderately acidic (5.5-6.5), 10% are near neutral (6.5-7.3), 3% are strongly acidic (below 5.5). Mapped soils run from pH 4.8 to 8.2, a spread of 3.4 units across 93 soil components. 87% 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 19.2% 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. 2% of mapped components carry free carbonate (lime already in the ground).

Coal against the rest of Oklahoma

pH 5.81 is 0.74 below the Oklahoma median of 6.55. 13 of 77 Oklahoma counties have more acidic topsoil. Nationally it is more acidic than the US county median of 6.05.

Closest in pH within the state: Pittsburg (5.63), Sequoyah (5.74), McIntosh (5.8), Atoka (5.81), Muskogee (5.86), Hughes (5.95), Okmulgee (5.97), Craig (5.99).

The range in Oklahoma runs from Adair at 5.12 to Beaver at 7.65; Coal sits 27% of the way up.