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2.2 Chemical Characteristics
Soil pH is an inherent property, resulting from formation by the weathering of the bedrock—
especially weathering from water. Bulk soil pH tends to be difficult to change, which is a good
thing for the most part because drastic changes in pH affect the chemical properties of the soil
environment, including nutrient availability and suitability for plant growth. This resistance to change
in soil pH is called “buffering capacity.”
Soil pH can affect nutrient availability in soil.
It is measured on a scale from 1-14.
Many of the soils in New Mexico and Colorado have high pH,
due to minimal or no weathering of the bedrock by water.
The presence of calcium carbonate (CaCO
3
) or lime is largely
responsible for buffering the pH of these soils in NM and CO.
Soil pH