Soil pH in Crawford, IA: Lime or Sulfur?

Typical topsoil pH in Crawford, IA

Typical topsoil in Crawford, IA is pH 6.17, already right for vegetable garden (6-7). Test before adding anything.

What Crawford needs, by plant

• Already in range: lawn (cool-season grass), vegetable garden, strawberries, roses, pink hydrangeas.
• Just outside, test first: tomatoes (off by 0), potatoes (off by 0.2), azaleas and rhododendrons (off by 0.2).
• Sulfur: blueberries 4.1 lb/100 sq ft over 3 applications; blue hydrangeas 3.1 lb/100 sq ft over 2 applications.

What to do next

If your test lands near 6.17, you can skip lime and sulfur for lawn (cool-season grass), vegetable garden, tomatoes, potatoes, strawberries, roses, azaleas and rhododendrons, pink hydrangeas.

How mixed the soil is

Of the 450,672 surveyed acres in Crawford, IA, 80% are moderately acidic (5.5-6.5), 11% are near neutral (6.5-7.3), 9% are alkaline (above 7.3). Mapped soils run from pH 5.6 to 8, a spread of 2.4 units across 291 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 28% clay and 2.88% organic matter, which this site treats as clay. Moving it one pH unit takes about 11.5 lb of lime or 3.4 lb of sulfur per 100 sq ft. 9% of mapped components carry free carbonate (lime already in the ground).

Crawford against the rest of Iowa

pH 6.17 is 0.19 below the Iowa median of 6.36. 9 of 99 Iowa counties have more acidic topsoil. Nationally it is more alkaline than the US county median of 6.05.

Closest in pH within the state: Montgomery (6.12), Cass (6.13), Monroe (6.15), Jefferson (6.16), Cherokee (6.18), Henry (6.18), Page (6.18), Sioux (6.2).

The range in Iowa runs from Van Buren at 6.02 to Monona at 7.11; Crawford sits 14% of the way up.