What are the two primary types of negative charges found on soil particles?

The correct choice highlights the nature of soil particle charges, which play a crucial role in how soils interact with nutrients, water, and other substances. The two primary types of negative charges found on soil particles are indeed permanently charged and pH-dependent charged.

Permanently charged sites are inherent to the clay minerals and organic matter in the soil. These charges do not change with variations in soil pH levels. They are stable and can hold onto cations, which are positively charged ions, making them available for plant uptake. This trait is vital for nutrient retention and availability in the soil.

On the other hand, pH-dependent charges are influenced by the soil's pH levels. At different pH levels, the surface charge of soil particles can change. For instance, as pH increases, more negative charges can develop, allowing for enhanced cation exchange capacity (CEC) at higher pH levels. Conversely, at low pH, certain sites may become protonated, leading to a decrease in negative charge. This dynamic nature makes pH-dependent charges significant in determining nutrient availability.

Together, these two types of charges explain the soil's ability to retain nutrients, buffer soil pH, and influence the overall fertility of the land. Understanding them is