What are soil minerals?

Soil minerals are the elements that are necessary for plant growth, along with nitrogen.   Besides air, water and soil life, these elements must be present in varying amounts in order for plants to be able to thrive.  They are classified by their elemental electrical charge as cations or anions.  The cations are: Calcium (Ca), Magnesium (Mg), Potassium (K), Sodium (Na), The anions are: Phosphorus (P), Sulfur (S), The micronutrients are: Iron (Fe), Copper (Cu), Zinc (Zn), Manganese (Mn) and Molybdenum (Mo).