Suggest the main functions and deficiency symptoms of nitrogen, magnesium and phosphorus to the plant

Nitrogen is required by plants to produce amino acids, proteins, and DNA. Nitrogen is necessary because it is a component of chlorophyll

Phosphorus promotes early root growth, winter hardiness, and seed formation, stimulates tillering, and increases water use efficiency.

• Leaves darken becoming gray, blue or dark green
• Leaves become shiny with yellow areas
• Leaves thicken becoming stiff and dry

• Sometimes the leaves turn purple or red