Plants need these elements in order to grow.

Freely available from air and water are

• C - Carbon 
  as carbon dioxide (CO2) from the air
• H – Hydrogen 
  from water (H2O) from rain and soil resources
• O – Oxygen (O2)  
  from the air

The following substances are partially found in the soil or, depending on the crop, must be added in order to assure optimum plant growth

• Nitrogen (N)
• Phosphorus (P)
• Potassium (K)
• Sulphur (S)
• Magnesium (Mg)
• Calcium (Ca)
• Micronutrients (B, Mn, Fe, Zn, Cu, Na Co, Mo, Cl, Si)