Soil pH in Wrangell-Petersburg Census Area, AK: Lime or Sulfur?
Typical topsoil pH in Wrangell-Petersburg Census Area, AK
Typical topsoil in Wrangell-Petersburg Census Area, AK is pH 4.94, too acidic for vegetable garden. Expect roughly 11.2 lb of lime per 100 sq ft, but only after a soil test confirms it.
What Wrangell-Petersburg Census Area needs, by plant
- Already in range: blueberries, azaleas and rhododendrons.
- Just outside, test first: potatoes (off by 0.1), blue hydrangeas (off by 0.1).
- Lime: lawn (cool-season grass) 11.2 lb/100 sq ft over 3 applications; vegetable garden 11.2 lb/100 sq ft over 3 applications; tomatoes 11.2 lb/100 sq ft over 3 applications; strawberries 7.7 lb/100 sq ft over 2 applications; roses 11.2 lb/100 sq ft over 3 applications; pink hydrangeas 9.1 lb/100 sq ft over 2 applications.
What to do next
If your test confirms pH near 4.94, spread about 112 lb of ground limestone per 1,000 sq ft of vegetable bed in 3 doses, ideally in fall.
How mixed the soil is
Of the 0 surveyed acres in Wrangell-Petersburg Census Area, AK, 92% are strongly acidic (below 5.5), 8% are moderately acidic (5.5-6.5). Mapped soils run from pH 4 to 6.7, a spread of 2.7 units across 391 soil components. 92% 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 4.9% clay and 8.02% organic matter, which this site treats as loam. At 8.02% organic matter the soil buffers like a heavier one, which pushes it into the loam bracket. Moving it one pH unit takes about 7 lb of lime or 2.3 lb of sulfur per 100 sq ft. None of the mapped components carry free carbonate.
Wrangell-Petersburg Census Area against the rest of Alaska
pH 4.94 is 0.32 below the Alaska median of 5.26. 5 of 27 Alaska counties have more acidic topsoil. Nationally it is more acidic than the US county median of 6.05.
Closest in pH within the state: Skagway Borough (4.84), Kenai Peninsula Borough (4.85), Anchorage Borough (4.89), Dillingham Census Area (4.94), Kodiak Island Borough (4.96), Kusilvak Census Area (old Wade Hampton) (5.04), Haines Borough (5.1), Valdez-Cordova Census Area (5.15).
The range in Alaska runs from Ketchikan Gateway Borough at 4.52 to Yakutat City and Borough at 6.08; Wrangell-Petersburg Census Area sits 27% of the way up.