Soil pH in Valdez-Cordova Census Area, AK: Lime or Sulfur?
Typical topsoil pH in Valdez-Cordova Census Area, AK
Typical topsoil in Valdez-Cordova Census Area, AK is pH 5.15, too acidic for vegetable garden. Expect roughly 9.1 lb of lime per 100 sq ft, but only after a soil test confirms it.
What Valdez-Cordova Census Area needs, by plant
- Already in range: potatoes, blueberries, azaleas and rhododendrons, blue hydrangeas.
- Lime: lawn (cool-season grass) 9.1 lb/100 sq ft over 2 applications; vegetable garden 9.1 lb/100 sq ft over 2 applications; tomatoes 9.1 lb/100 sq ft over 2 applications; strawberries 5.6 lb/100 sq ft over 2 applications; roses 9.1 lb/100 sq ft over 2 applications; pink hydrangeas 7.7 lb/100 sq ft over 2 applications.
What to do next
If your test confirms pH near 5.15, spread about 91 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 255,539 surveyed acres in Valdez-Cordova Census Area, AK, 93% are strongly acidic (below 5.5), 6% are moderately acidic (5.5-6.5). Mapped soils run from pH 4.3 to 8.2, a spread of 3.9 units across 52 soil components. 93% 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 5.5% clay and 5.87% organic matter, which this site treats as loam. At 5.87% 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. 0% of mapped components carry free carbonate (lime already in the ground).
Valdez-Cordova Census Area against the rest of Alaska
pH 5.15 is 0.11 below the Alaska median of 5.26. 10 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: Wrangell-Petersburg Census Area (4.94), Kodiak Island Borough (4.96), Kusilvak Census Area (old Wade Hampton) (5.04), Haines Borough (5.1), Matanuska-Susitna Borough (5.2), Northwest Arctic Borough (5.23), Kusilvak Census Area (5.26), Juneau Borough (5.3).
The range in Alaska runs from Ketchikan Gateway Borough at 4.52 to Yakutat City and Borough at 6.08; Valdez-Cordova Census Area sits 40% of the way up.