Soil pH in Mercer, KY: Lime or Sulfur?

Typical topsoil pH in Mercer, KY

Typical topsoil in Mercer, KY is pH 6.34, already right for vegetable garden (6-7). Test before adding anything.

What Mercer needs, by plant

• Already in range: lawn (cool-season grass), vegetable garden, tomatoes, strawberries, roses, pink hydrangeas.
• Sulfur: potatoes 1.8 lb/100 sq ft; blueberries 3 lb/100 sq ft over 2 applications; azaleas and rhododendrons 2.5 lb/100 sq ft over 2 applications; blue hydrangeas 2.5 lb/100 sq ft over 2 applications.

What to do next

If your test lands near 6.34, you can skip lime and sulfur for lawn (cool-season grass), vegetable garden, tomatoes, strawberries, roses, pink hydrangeas.

How mixed the soil is

Of the 149,383 surveyed acres in Mercer, KY, 58% are moderately acidic (5.5-6.5), 31% are near neutral (6.5-7.3), 10% are alkaline (above 7.3), 1% are strongly acidic (below 5.5). Mapped soils run from pH 5.3 to 7.5, a spread of 2.2 units across 104 soil components. No single class covers 60% of the county, so two gardens a few miles apart here can need opposite treatments. Test your own bed.

Clay, organic matter and rates

Topsoil here averages 26.6% clay and 2.65% 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. 9% of mapped components carry free carbonate (lime already in the ground).

Mercer against the rest of Kentucky

pH 6.34 is 0.55 above the Kentucky median of 5.79. 107 of 120 Kentucky counties have more acidic topsoil. Nationally it is more alkaline than the US county median of 6.05.

Closest in pH within the state: Scott (6.27), Washington (6.28), Clark (6.3), Spencer (6.33), Nicholas (6.34), Bourbon (6.37), Fayette (6.39), Harrison (6.4).

The range in Kentucky runs from Greenup at 5.09 to Carroll at 6.63; Mercer sits 81% of the way up.