Soil pH in Isanti, MN: Lime or Sulfur?

Typical topsoil pH in Isanti, MN

Typical topsoil in Isanti, MN is pH 5.92, just outside the 6-7 range for vegetable garden. Test first; it may need nothing.

What Isanti needs, by plant

• Already in range: potatoes, strawberries, azaleas and rhododendrons.
• Just outside, test first: lawn (cool-season grass) (off by 0.1), vegetable garden (off by 0.1), roses (off by 0.1), pink hydrangeas (off by 0.1).
• Lime: tomatoes 1.8 lb/100 sq ft.
• Sulfur: blueberries 1.1 lb/100 sq ft; blue hydrangeas 0.8 lb/100 sq ft.

What to do next

If your test lands near 5.92, 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 240,836 surveyed acres in Isanti, MN, 89% are moderately acidic (5.5-6.5), 8% are near neutral (6.5-7.3), 3% are strongly acidic (below 5.5). Mapped soils run from pH 5.2 to 7.8, a spread of 2.6 units across 221 soil components. 89% 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 9.3% clay and 2.46% organic matter, which this site treats as sandy. Moving it one pH unit takes about 3 lb of lime or 1.2 lb of sulfur per 100 sq ft. 0% of mapped components carry free carbonate (lime already in the ground).

Isanti against the rest of Minnesota

pH 5.92 is 0.72 below the Minnesota median of 6.64. 8 of 87 Minnesota counties have more acidic topsoil. Nationally it is more acidic than the US county median of 6.05.

Closest in pH within the state: Carlton (5.59), Pine (5.84), Chisago (5.87), Kanabec (5.91), Cass (5.94), Mille Lacs (5.96), Benton (5.99), Morrison (5.99).

The range in Minnesota runs from Cook at 5.21 to Swift at 7.49; Isanti sits 31% of the way up.