Soil pH in Merced, CA: Lime or Sulfur?

Typical topsoil pH in Merced, CA

Typical topsoil in Merced, CA is pH 7.27 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 Merced 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 7.27, consider raised beds for anything acid-loving; with 34% of soils here carrying free lime, sulfur will not hold.

How mixed the soil is

Of the 1,021,328 surveyed acres in Merced, CA, 49% are alkaline (above 7.3), 39% are near neutral (6.5-7.3), 12% are moderately acidic (5.5-6.5), 1% are strongly acidic (below 5.5). Mapped soils run from pH 5 to 8.8, a spread of 3.8 units across 572 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 22.8% clay and 1.37% 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. 34% of mapped components carry free carbonate (lime already in the ground), enough that sulfur gets neutralised before it does much.

Merced against the rest of California

pH 7.27 is 0.73 above the California median of 6.54. 51 of 58 California counties have more acidic topsoil. Nationally it is more alkaline than the US county median of 6.05.

Closest in pH within the state: Orange (7.12), San Luis Obispo (7.12), Riverside (7.15), Ventura (7.22), Tulare (7.27), Kern (7.49), San Bernardino (7.61), Kings (7.92).

The range in California runs from Del Norte at 5.43 to Imperial at 8.16; Merced sits 67% of the way up.