Soil pH in Ottawa, KS: Lime or Sulfur?

Typical topsoil pH in Ottawa, KS

Typical topsoil in Ottawa, KS is pH 6.25, already right for vegetable garden (6-7). Test before adding anything.

What Ottawa 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 2.3 lb/100 sq ft over 2 applications; blue hydrangeas 2.3 lb/100 sq ft over 2 applications.

What to do next

If your test lands near 6.25, 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 457,561 surveyed acres in Ottawa, KS, 71% are moderately acidic (5.5-6.5), 20% are near neutral (6.5-7.3), 9% are alkaline (above 7.3). Mapped soils run from pH 5.7 to 8.2, a spread of 2.5 units across 225 soil components. 71% 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 23.8% clay and 2.81% 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).

Ottawa against the rest of Kansas

pH 6.25 is 0.32 below the Kansas median of 6.57. 23 of 105 Kansas counties have more acidic topsoil. Nationally it is more alkaline than the US county median of 6.05.

Closest in pH within the state: Johnson (6.23), Shawnee (6.23), Labette (6.24), Neosho (6.25), Wilson (6.25), Jefferson (6.26), Osage (6.26), Cloud (6.27).

The range in Kansas runs from Cherokee at 5.95 to Wallace at 7.51; Ottawa sits 19% of the way up.