Soil pH in Yukon-Koyukuk Census Area, AK: Lime or Sulfur?
Typical topsoil pH in Yukon-Koyukuk Census Area, AK
Typical topsoil in Yukon-Koyukuk Census Area, AK is pH 5.9, just outside the 6-7 range for vegetable garden. Test first; it may need nothing.
What Yukon-Koyukuk Census Area 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 4.2 lb/100 sq ft.
- Sulfur: blueberries 2.1 lb/100 sq ft over 2 applications; blue hydrangeas 1.6 lb/100 sq ft.
What to do next
If your test lands near 5.9, 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 17,315,117 surveyed acres in Yukon-Koyukuk Census Area, AK, 36% are moderately acidic (5.5-6.5), 34% are strongly acidic (below 5.5), 15% are near neutral (6.5-7.3), 15% are alkaline (above 7.3). Mapped soils run from pH 3.4 to 10, a spread of 6.6 units across 1,527 soil components. No single class covers 60% of the county, so two gardens a few miles apart here can need opposite treatments. Test your own bed.
Clay, organic matter and rates
Topsoil here averages 9% clay and 6.11% organic matter, which this site treats as loam. At 6.11% 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. 7% of mapped components carry free carbonate (lime already in the ground).
Yukon-Koyukuk Census Area against the rest of Alaska
pH 5.9 is 0.64 above the Alaska median of 5.26. 23 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: Fairbanks North Star Borough (5.56), Bethel Census Area (5.57), North Slope Borough (5.62), Southeast Fairbanks Census Area (5.66), Denali Borough (5.94), Hoonah-Angoon Census Area (6.06), Yakutat City and Borough (6.08).
The range in Alaska runs from Ketchikan Gateway Borough at 4.52 to Yakutat City and Borough at 6.08; Yukon-Koyukuk Census Area sits 88% of the way up.