A variety of mineral elements is present in the soil but all of them are not essential for plant growth. Plants take in small quantity of mineral salts through soil water for their growth.

About 98 per cent of the mass of every living organism including bacterium and human beings is composed of just six elements, ie, carbon (C), hydrogen (H), nitrogen (N), oxygen (O), phosphorus (P) and sulphur (S).

• Phosphorus is a constituent of energy carriers(ATP) phospholipids kf membrane DNA and RNA etc.
• Sulphur present in amino acids cystiene and methionine

The essential elements, which are required by plants in comparatively large amounts are called as macronutrients eg, C, H, O, N, P, K, Ca, S, Mg, Fe. 

The essential elements, which are required in very small amount by the plants are called micronutrients, eg, Zn, Mn, B, Cu, Mo and Cl.

Element present in middle lamella is Ca in the form of calcium pectate. It provides mechanical support to the cell wall.

Magnesium is absorbed by plants in the form of divalent magnesium. It activates several enzymes involved in the process of photosynthesis and respiration.It also play a major role in splitting of water to liberate oxygen, during photosynthesis

Mutant strains of nitrogen-fixing bacteria have been obtained with defects in their ability to synthesize an active molybdenum cofactor. Ammonia in the medium represses the synthesis of the molybdenum cofactor. Molybdenum is transported by an energy-requiring reaction, and the metal becomes part of a molybdenum storage compound. Molybdenum in the medium affects the regulation of nitrogenase synthesis.

Calcium oxalate occurs in bundles (rounded masses) or singly in certain plant cells.

Sand does not contain enough nutrient material to sustain plant growth, so the plants die from starvation.