What is the soil property called that resists changes to pH?

The term for the soil property that resists changes to pH is buffering capacity. This concept pertains to the ability of soil to maintain a stable pH level despite the addition of acids or bases. Soil buffering is primarily influenced by the presence of clay minerals and organic matter, which can absorb excess hydrogen ions (H+) and release them when there is a decrease in acidity. This quality is essential for plant health, as sudden changes in pH can adversely affect nutrient availability and microbial activity in the soil. A high buffering capacity indicates that the soil can sustain its pH level effectively, offering a more stable environment for plant growth.

In contrast, cation exchange capacity refers to the soil’s ability to retain and exchange cations, which are positively charged ions, but it does not specifically relate to pH stability. Water holding capacity is the soil's ability to retain moisture, and soil permeability describes how easily water can move through the soil. Neither of these properties directly addresses the stabilization of pH.