Question: what are the 16 essential elements for plant growth?
Answer: Supplied by air and water: carbon, hydrogen, oxygen.
Macronutrients: nitrogen, phosphorous, potassium.
Secondary Nutrients: calcium, magnesium, sulfur.
Micronutrients: boron (B), chlorine (Cl), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), and zinc (Zn).