There are 16 nutrient elements required to grow crops:
Carbon (C), Hydrogen (H) and oxygen (O) are taken from atmospheric carbon dioxide and water.
The other 13 nutrients are taken up from the soil and are usually grouped as:
Nitrogen (N), Phosphore (P), and Potassium (K) are commonly found in balanced fertilizers such as
20-20-20 and utilize in the largest amount by crops.
Calcium (Ca), Magnesium (Mg) and Sulfur are required in smaller amount than primary nutrients.
These nutrients are available from a variety of fertilizer sources.
Iron (Fe), Manganese (Mn), Zinc (Zn), Copper (Cu), Boron (B) and molybdenum (Mo).