Soil pH in Taos, NM: Lime or Sulfur?

Typical topsoil pH in Taos, NM

Typical topsoil in Taos, NM is pH 7.04, just outside the 6-7 range for vegetable garden. Test first; it may need nothing.

What Taos needs, by plant

• Just outside, test first: lawn (cool-season grass) (off by 0), vegetable garden (off by 0), tomatoes (off by 0.2), roses (off by 0).
• Sulfur: potatoes 3.5 lb/100 sq ft over 2 applications; strawberries 2.3 lb/100 sq ft over 2 applications; blueberries 4.6 lb/100 sq ft over 3 applications; azaleas and rhododendrons 4.1 lb/100 sq ft over 3 applications; blue hydrangeas 4.1 lb/100 sq ft over 3 applications; pink hydrangeas 1.8 lb/100 sq ft.

What to do next

If your test lands near 7.04, you can skip lime and sulfur for lawn (cool-season grass), vegetable garden, tomatoes, roses.

How mixed the soil is

Of the 1,108,421 surveyed acres in Taos, NM, 44% are near neutral (6.5-7.3), 38% are alkaline (above 7.3), 11% are moderately acidic (5.5-6.5), 8% are strongly acidic (below 5.5). Mapped soils run from pH 4.6 to 8.5, a spread of 3.9 units across 288 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 18.7% clay and 1.59% 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. 29% of mapped components carry free carbonate (lime already in the ground).

Taos against the rest of New Mexico

pH 7.04 is 0.61 below the New Mexico median of 7.65. 2 of 33 New Mexico counties have more acidic topsoil. Nationally it is more alkaline than the US county median of 6.05.

Closest in pH within the state: Colfax (6.99), Los Alamos (7.02), Rio Arriba (7.23), Mora (7.25), Catron (7.26), Cibola (7.39).

The range in New Mexico runs from Colfax at 6.99 to Valencia at 8.07; Taos sits 5% of the way up.