Macronutrients &Micronutrients

Macronutrients, as the name suggests, are the nutrients required by the plants in large amounts. These include Carbon, Hydrogen, Oxygen, are obtained from air and water while the others are obtained from the soil. Macronutrients are the ones required in very small amount by the plants. These include Iron(Fe), Zinc(zn), etc. In addition to these, some elements like silicon, cobalt, selenium & sodium are present which are required by the higher plants. 

The elements referred to as macronutrients and micronutrients can be further divided in following categories :

• Elements as components of biomolecules & hence are structural elements of the cell. eg; carbon, nitrogen, oxygen etc.

• Elements that are component of energy-related chemical compounds in plants like Phosphorus in ATP.

• Elements that help inactivation or inhibition of enzymes. eg; Zinc which helps in the activation of alcohol dehydrogenase. 

• Elements which alter the water potential (osmotic potential) of the cell.

Functions of Macronutrients and Micronutrients in Plant:

All the essential elements perform several functions like they maintain the osmotic concentration of the cell sap, have buffering action, show enzymatic activity and act as a major constituents of macromolecules & coenzymes.

Functions of some important elements are as follows:

1. Nitrogen: It is required by plants in large amounts. It is taken in the form of ions from the soil. It is required for the division of cells. It is the major constituent of protein, vitamins, hormones etc.

2. Phosphorus: It is a constituent of cell membrane, proteins of nucleic acids and is required for certain important reaction.

3. Potassium: It is a mineral i.e; required in the growing parts of the plants in large amounts. It is also required for the opening and closing of the stomata. It helps in the activation of the enzymes and helps in the maintaining the turbidity of the cell.

4. Calcium: It is required during cell division and in the normal functioning of the cell membrane. Metabolic activities are also regulated by this mineral.

5. Magnesium: It is involved in the activation of enzymes in respiration & photosynthesis & helps in the synthesis of DNA& RNA. It is also an important constituent of ribosomes and helps in maintaining the structure of the ribosome.

6. Sulfur: It is an important constituent of amino acids, coenzymes and vitamins.

7. Iron: It is required in larger amount as compared to other micronutrients. It is an important constituent of protein and helps with the activation of enzymes.

8. Manganese: Enzymes involved in photosynthesis, respiration etc are activated by this. It helps in the splitting of water during photosynthesis.

9. Zinc& Copper: These are also involved in the activation of certain enzymes. Interstitial fluid helps in the uptake& utilization of calcium, functioning of the membrane, pollen germination, cell elongation, germination etc. Molybdenum is a component of certain enzymes like nitrogen etc.

10. Chlorine: Chlorine helps in determining the solute concentration& the anion-cation balance of the cell.