Soil pH in Dukes, MA: Lime or Sulfur?

Typical topsoil pH in Dukes, MA

Typical topsoil in Dukes, MA is pH 4.66, too acidic for vegetable garden. Expect roughly 5.4 lb of lime per 100 sq ft, but only after a soil test confirms it.

What Dukes needs, by plant

• Already in range: blueberries, azaleas and rhododendrons.
• Lime: lawn (cool-season grass) 5.4 lb/100 sq ft over 2 applications; vegetable garden 5.4 lb/100 sq ft over 2 applications; tomatoes 5.4 lb/100 sq ft over 2 applications; potatoes 2.4 lb/100 sq ft; strawberries 3.9 lb/100 sq ft; roses 5.4 lb/100 sq ft over 2 applications; blue hydrangeas 1.8 lb/100 sq ft; pink hydrangeas 4.8 lb/100 sq ft.

What to do next

If your test confirms pH near 4.66, spread about 54 lb of ground limestone per 1,000 sq ft of vegetable bed in 2 doses, ideally in fall.

How mixed the soil is

Of the 58,894 surveyed acres in Dukes, MA, 91% are strongly acidic (below 5.5), 5% are moderately acidic (5.5-6.5), 2% are near neutral (6.5-7.3), 2% are alkaline (above 7.3). Mapped soils run from pH 3.8 to 7.9, a spread of 4.1 units across 191 soil components. 91% 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 4.3% clay and 2.7% 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. 3% of mapped components carry free carbonate (lime already in the ground).

Dukes against the rest of Massachusetts

pH 4.66 is 0.36 below the Massachusetts median of 5.02. 1 of 14 Massachusetts counties have more acidic topsoil. Nationally it is more acidic than the US county median of 6.05.

Closest in pH within the state: Nantucket (4.64), Barnstable (4.67), Plymouth (4.79), Franklin (5), Hampden (5.02).

The range in Massachusetts runs from Nantucket at 4.64 to Hampshire at 5.28; Dukes sits 3% of the way up.