Soil pH in La Paz, AZ: Lime or Sulfur?

Typical topsoil pH in La Paz, AZ

Typical topsoil in La Paz, AZ is pH 8.02 and calcareous, so sulfur won't lower it for long. For vegetable garden, choose alkaline-tolerant varieties and add compost rather than fighting the soil.

What La Paz needs, by plant

• Beds or pots instead: lawn (cool-season grass), vegetable garden, tomatoes, potatoes, strawberries, roses, blueberries, azaleas and rhododendrons, blue hydrangeas, pink hydrangeas.

What to do next

If your test confirms pH near 8.02, consider raised beds for anything acid-loving; with 94% of soils here carrying free lime, sulfur will not hold.

How mixed the soil is

Of the 2,515,404 surveyed acres in La Paz, AZ, 98% are alkaline (above 7.3), 2% are near neutral (6.5-7.3). Mapped soils run from pH 6.2 to 9.2, a spread of 3 units across 293 soil components. 98% 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 11.4% clay and 0.44% organic matter, which this site treats as loam. Moving it one pH unit takes about 7 lb of lime or 2.3 lb of sulfur per 100 sq ft. 94% of mapped components carry free carbonate (lime already in the ground), enough that sulfur gets neutralised before it does much.

La Paz against the rest of Arizona

pH 8.02 is 0.25 above the Arizona median of 7.77. 11 of 14 Arizona counties have more acidic topsoil. Nationally it is more alkaline than the US county median of 6.05.

Closest in pH within the state: Apache (7.79), Coconino (7.81), Mohave (7.83), Navajo (7.84), Yuma (8.09), Maricopa (8.12).

The range in Arizona runs from Gila at 7.17 to Maricopa at 8.12; La Paz sits 89% of the way up.