Soil Fertility and Nutrient management (1+1)

Definitions of Primary and secondary nutrient

Definitions

• Macro or Major Nutrients: They are the nutrients utilized by the plants in relatively large amounts (quantity) for their growth and development.

  Eg: C, H. O. N, P, K, Ca, Mg and S (C, H and O are abundantly present in the atmosphere and need not be applied through fertilizers).
• Primary nutrients: are those nutrients required relatively in large quantities by the plants for their growth and development. These are also designated as ‘fertilizer elements’ because, deficiency of these elements is corrected by application through fertilizers.

  Eg: N, P and K
• Secondary nutrients: are those nutrients which are required by plants in moderate amounts. They are called secondary because they are unknowingly supplied through fertilizers and other amendments. However their role in nutrition is not secondary but they are given secondary importance in its supply and management.

  Eg: Ca, Mg & S
  Ex: When SSP is applied as a fertilizer for P it supply Ca and S
  Dolomite applied as a liming material supply Ca and Mg.
  Ammonium Sulphate added as N fertilizer will supply S
• Micronutrients: The nutrients which are required by plants in relatively smaller quantities for their growth and development, but these are equally important and essential to plants as macronutrients. They are also called as trace/rare/nano elements.

  These include Fe, Mn, Zn, Cu, B, Mo, Cl and Ni.