Soil pH in Dallas, MO: Lime or Sulfur?

Typical topsoil pH in Dallas, MO

Typical topsoil in Dallas, MO is pH 5.85, just outside the 6-7 range for vegetable garden. Test first; it may need nothing.

What Dallas 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 5.85, 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 345,753 surveyed acres in Dallas, MO, 52% are moderately acidic (5.5-6.5), 28% are strongly acidic (below 5.5), 21% are near neutral (6.5-7.3). Mapped soils run from pH 4.5 to 7.3, a spread of 2.8 units across 226 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 16.1% 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. None of the mapped components carry free carbonate.

Dallas against the rest of Missouri

pH 5.85 is 0.28 below the Missouri median of 6.13. 33 of 114 Missouri counties have more acidic topsoil. Nationally it is more acidic than the US county median of 6.05.

Closest in pH within the state: Dade (5.78), Cedar (5.79), Benton (5.84), Barton (5.85), Maries (5.85), Perry (5.87), Vernon (5.89), Gasconade (5.9).

The range in Missouri runs from Carter at 5.08 to Knox at 6.71; Dallas sits 47% of the way up.