Soil pH in Bristol, RI: Lime or Sulfur?

Typical topsoil pH in Bristol, RI

Typical topsoil in Bristol, RI is pH 5.21, too acidic for vegetable garden. Expect roughly 3.9 lb of lime per 100 sq ft, but only after a soil test confirms it.

What Bristol needs, by plant

• Already in range: potatoes, blueberries, azaleas and rhododendrons, blue hydrangeas.
• Lime: lawn (cool-season grass) 3.9 lb/100 sq ft; vegetable garden 3.9 lb/100 sq ft; tomatoes 3.9 lb/100 sq ft; strawberries 2.4 lb/100 sq ft; roses 3.9 lb/100 sq ft; pink hydrangeas 3 lb/100 sq ft.

What to do next

If your test confirms pH near 5.21, spread about 39 lb of ground limestone per 1,000 sq ft of vegetable bed, ideally in fall.

How mixed the soil is

Of the 14,747 surveyed acres in Bristol, RI, 84% are strongly acidic (below 5.5), 13% are moderately acidic (5.5-6.5), 3% are near neutral (6.5-7.3). Mapped soils run from pH 4.2 to 7, a spread of 2.8 units across 358 soil components. 84% 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 5% clay and 4.46% 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. None of the mapped components carry free carbonate.

Bristol against the rest of Rhode Island

pH 5.21 is 0.13 above the Rhode Island median of 5.08. 3 of 5 Rhode Island counties have more acidic topsoil. Nationally it is more acidic than the US county median of 6.05.

Closest in pH within the state: Providence (4.97), Kent (5), Washington (5.08), Newport (5.21).

The range in Rhode Island runs from Providence at 4.97 to Newport at 5.21; Bristol sits 100% of the way up.