Plants are living organisms and they also require nutrients like us in order to survive, grow, reproduce, and develop. Macronutrients in plants are nutrients that provide energy to the plants and are required in larger amounts to maintain their development and growth.

Pritish Kumar Halder illustrates essential micronutrients, their role and their functions in plants.

These are the most important elements required for crops and examples include nitrogen (N), potassium (K), calcium (Ca), phosphorus (P), magnesium (Mg), sulphur (S), oxygen (O), carbon (C), and hydrogen (H).

Out of these, the most important ones are nitrogen, phosphorus, and potassium, which directly affect plant growth and actually create various parts of the plant. Also, nitrogen is an important component of chlorophyll that plays a vital role in photosynthesis (food synthesising process).

Role of Macro and Micronutrients

Macronutrients and micronutrients in plants fall under essential nutrients that support plants for all biochemical needs and without which:

  • A plant can’t complete its life cycle.
  • Other elements can’t replace a specific function for a plant.
  • Plants cannot get full nutrition as each essential nutrient is directly involved in plant nutrition.

Out of all the essential nutrients, about half of the elements are considered as macronutrients and functions of macronutrients are very necessary, for example, carbon is required to form proteins, carbohydrates, nucleic acids, and other compounds or key plant macromolecules.

Role of macro and micronutrient

List of Macronutrients

Carbon (C)
Hydrogen (H)
Oxygen (O)
Nitrogen (N)
Phosphorus (P)
Calcium (Ca)
Potassium (K)
Magnesium (Mg)
Sulphur (S)

All the elements are important for plants, some in larger quantities called macronutrients and some in lesser or minute quantities called micronutrients.

Functions of Macronutrients and Micronutrients

It is good to know the structure and functions of macro and micro nutrients for gaining information about these in a better way and recognize the role of each of them. Let’s know the functions they perform in the plants for macronutrients:

Macronutrients in Plants and Their Functions

The most important crop nutrients are nitrogen, phosphorus, and potassium that affect plant growth directly and create various parts of plants.


It is important to plants for:

  • Metabolism as it is an important substance and part of amino acids, proteins, and enzymes.
  • Influences germination and vegetative growth.
  • Being a component of chlorophyll, it plays an important role in photosynthesis.
  • Responsible for the rapid growth of foliage.
  • Provides green colour to the plants.

Deficiency of iron in plants results in stunted crop growth, chlorosis or yellowing of leaves, and weakness during fruiting and flowering, leading to lower yields.

Too much nitrogen is also not good for plants as it causes dark green colouring of leaves, lush growth, crop lodging, and fruit quality reduction.


It is important to plants for:

  • Development of roots.
  • Maintaining a good quality of flowering, fruiting, and seed production.
  • Storing and transporting energy.
  • Resistance to disease.

Deficiency of phosphorus leads to stunted plant growth, weakened roots, thin shoots, and dark green/purple/red leaves. Excessive amounts of phosphorus can cause lower reception and deficiency of other elements like Zn, Fe, Cu, Mn, and B.

Potassium (K)

It is important to plants for:

  • Influencing water uptake.
  • Improving drought tolerance.
  • Improvement in cold hardiness.
  • Providing resistance to fungal diseases and insect pests.
  • Synthesizing proteins, sugar, and fat.

Deficiency of potassium in plants leads to growth reduction, burning or yellowing of the leaf margins, and dead spots on older leaves. Excess amounts are also not so beneficial as they affect the uptake of other nutrients including magnesium, calcium, and nitrogen.