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Macronutrients and Micronutrients in Fertilizers: Essential for Plant Growth

Updated: Jun 12


Macro and Micro Nutrient Element Symbols


Macronutrients and Micronutrients in Fertilizers: Essential for Plant Growth

Macronutrients in fertilizers are essential elements that plants require in relatively large amounts for growth and development. These macronutrients are classified into three primary categories: nitrogen (N), phosphorus (P), and potassium (K), often referred to as N-P-K. Additionally, secondary macronutrients include calcium (Ca), magnesium (Mg), and sulfur (S).

Primary Macronutrients

  • Nitrogen (N): Promotes leaf and stem growth, chlorophyll production, and overall plant vigor.

  • Common Sources: Ammonium nitrate, urea, ammonium sulfate.

  • Phosphorus (P): Essential for root development, energy transfer (ATP), and flowering/fruiting.

  • Common Sources: Superphosphate, monoammonium phosphate (MAP), diammonium phosphate (DAP).

  • Potassium (K): Regulates water uptake, enzyme activation, and enhances disease resistance.

  • Common Sources: Potassium chloride (muriate of potash), potassium sulfate, potassium nitrate.

Secondary Macronutrients

  • Calcium (Ca): Strengthens cell walls, aids in root and leaf development, and helps with nutrient uptake.

  • Common Sources: Calcium nitrate, calcium sulfate (gypsum), lime (calcium carbonate).

  • Magnesium (Mg): Central component of chlorophyll, activates enzymes, and aids in photosynthesis.

  • Common Sources: Magnesium sulfate (Epsom salt), dolomitic lime, magnesium oxide.

  • Sulfur (S): Vital for protein synthesis, enzyme function, and chlorophyll formation.

  • Common Sources: Ammonium sulfate, gypsum, elemental sulfur.

Summary of Macronutrient Functions and Sources



Common Sources

Nitrogen (N)

Leaf and stem growth, chlorophyll production

Ammonium nitrate, urea, ammonium sulfate

Phosphorus (P)

Root development, energy transfer (ATP), flowering

Superphosphate, monoammonium phosphate (MAP), diammonium phosphate (DAP)

Potassium (K)

Water regulation, enzyme activation, disease resistance

Potassium chloride, potassium sulfate, potassium nitrate

Calcium (Ca)

Cell wall strength, root/leaf development, nutrient uptake

Calcium nitrate, calcium sulfate (gypsum), lime (calcium carbonate)

Magnesium (Mg)

Chlorophyll component, enzyme activation, photosynthesis

Magnesium sulfate, dolomitic lime, magnesium oxide

Sulfur (S)

Protein synthesis, enzyme function, chlorophyll formation

Ammonium sulfate, gypsum, elemental sulfur



Micronutrients are essential elements that plants need in smaller quantities compared to macronutrients, but they are crucial for various physiological and biochemical processes. The main micronutrients in fertilizers include:

Essential Micronutrients

  • Boron (B): Cell wall formation, membrane integrity, and reproductive growth.

  • Common Sources: Borax, boric acid, solubor.

  • Chlorine (Cl): Osmosis and ionic balance, photosynthesis, disease resistance.

  • Common Sources: Potassium chloride, calcium chloride.

  • Copper (Cu): Enzyme activation, photosynthesis, respiration, lignin synthesis.

  • Common Sources: Copper sulfate, copper chelates, copper oxide.

  • Iron (Fe): Chlorophyll synthesis, enzyme function, electron transport.

  • Common Sources: Ferrous sulfate, iron chelates (e.g., Fe-EDDHA, Fe-EDTA).

  • Manganese (Mn): Enzyme activation, photosynthesis, nitrogen metabolism.

  • Common Sources: Manganese sulfate, manganese chelates.

  • Molybdenum (Mo): Nitrogen fixation, nitrate reduction, enzyme cofactor.

  • Common Sources: Sodium molybdate, ammonium molybdate.

  • Nickel (Ni): Urease activity, nitrogen metabolism, seed germination.

  • Common Sources: Nickel sulfate, nickel chelates.

  • Zinc (Zn): Enzyme activation, protein synthesis, growth regulation.

  • Common Sources: Zinc sulfate, zinc chelates, zinc oxide.

Summary of Micronutrient Functions and Sources



Common Sources

Boron (B)

Cell wall formation, membrane integrity, reproductive growth

Borax, boric acid, solubor

Chlorine (Cl)

Osmosis and ionic balance, photosynthesis, disease resistance

Potassium chloride, calcium chloride

Copper (Cu)

Enzyme activation, photosynthesis, respiration, lignin synthesis

Copper sulfate, copper chelates, copper oxide

Iron (Fe)

Chlorophyll synthesis, enzyme function, electron transport

Ferrous sulfate, iron chelates (e.g., Fe-EDDHA, Fe-EDTA)

Manganese (Mn)

Enzyme activation, photosynthesis, nitrogen metabolism

Manganese sulfate, manganese chelates

Molybdenum (Mo)

Nitrogen fixation, nitrate reduction, enzyme cofactor

Sodium molybdate, ammonium molybdate

Nickel (Ni)

Urease activity, nitrogen metabolism, seed germination

Nickel sulfate, nickel chelates

Zinc (Zn)

Enzyme activation, protein synthesis, growth regulation

Zinc sulfate, zinc chelates, zinc oxide

Importance of Micronutrients

  • Essential for Enzyme Function: Many micronutrients act as cofactors for enzymes, which are vital for metabolic processes in plants.

  • Photosynthesis and Respiration: Micronutrients like iron and manganese are crucial for the photosynthetic process and respiration.

  • Disease Resistance: Some micronutrients help enhance the plant's ability to resist diseases and stress.

  • Growth and Development: Proper availability of micronutrients is necessary for optimal plant growth, flowering, and fruiting.

Application of Micronutrients

  • Soil Application: Directly added to the soil to improve nutrient availability.

  • Foliar Spray: Dissolved in water and sprayed on plant leaves for immediate uptake.

  • Seed Treatment: Coating seeds with micronutrients to ensure they are available during germination.

Macronutrients and Micronutrients in Fertilizer

Ensuring the proper balance of macronutrients and micronutrients is essential for healthy plant growth and optimal crop yields. Understanding these nutrients and their roles is crucial for formulating effective fertilization strategies to optimize plant growth and yield.



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