Soil pH in Caldwell, KY: Lime or Sulfur?

Typical topsoil pH in Caldwell, KY

Typical topsoil in Caldwell, KY is pH 5.76, just outside the 6-7 range for vegetable garden. Test first; it may need nothing.

What Caldwell 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 1.2 lb/100 sq ft.

What to do next

If your test lands near 5.76, 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 202,513 surveyed acres in Caldwell, KY, 68% are moderately acidic (5.5-6.5), 28% are strongly acidic (below 5.5), 4% are near neutral (6.5-7.3). Mapped soils run from pH 3.6 to 7, a spread of 3.4 units across 123 soil components. 68% 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% clay and 1.94% 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.

Caldwell against the rest of Kentucky

pH 5.76 is right at the Kentucky median of 5.79. 57 of 120 Kentucky counties have more acidic topsoil. Nationally it is more acidic than the US county median of 6.05.

Closest in pH within the state: Marshall (5.74), Trigg (5.74), Warren (5.74), Hancock (5.75), Logan (5.78), Meade (5.78), Crittenden (5.79), Marion (5.79).

The range in Kentucky runs from Greenup at 5.09 to Carroll at 6.63; Caldwell sits 44% of the way up.