Top 3 macronutrients NPK, select fertilizers based on NPK

by | May 22, 2021 | Blog, Farming | 0 comments

macronutrients NPK

Importance of NPK Fertilizers in Grow Bag Farming

NPK (Nitrogen, phosphorus, Potassium) are considered as macronutrients, it is called so because it is needed in large quantities for the healthy development of plants. Most of the fertilizer packages we get in the market come with a ratio printed on them say for example 19:19:19 or 30:14:14 etc it means the ratio of NPK in the fertilizer mix. So it is very important to know the role of these macronutrients in plant growth. Apart from these other macronutrients are Ca, Mg and S, in this write up we can limit our discussion to NPK.

Role of Nitrogen (N) in Plants

Nitrogen is an important element for the growth of plants. Its paucity affects the growth of the plant. Nitrogen is the nutrient that normally produces the greatest yield response in crop plants, promoting rapid vegetative growth and giving the plant a healthy green color.

  • Nitrogen(N) is a major component of chlorophyll, the compound by which plants use sunlight energy during photosynthesis
  • Nitrogen(N) is a significant component of nucleic acids such as DNA, the genetic material that allows plants to grow and reproduce
  • Nitrogen(N) is an essential part of living cells and a component of proteins and enzymes essential for metabolic processes
  • Nitrogen(N) is a component of ATP, the energy-transfer compound which allows cells to use the energy released in metabolism
  • Nitrogen(N) stimulates root growth and crop development as well as uptake of other nutrients

Symptoms of Nitrogen Deficiency

  • Growth is usually stunted
  • Since nitrogen is mobile within the plant, deficiency symptoms appear on lower and older leaves first
  • General yellow if of older leaves (bottom of the plant )The rest of the plant is often light green

The role of Phosphorus(P) in crops

Phosphorus (P) is an essential nutrient, Phosphorus is a component of various enzymes and proteins. It is a vital component of DNA and RNA. Phosphorus is essential for the general health and vigor of all plants.

  • Phosphorus(P) has an essential role in photosynthesis
  • Phosphorus(P) improves flower formation and seed production and promotes more uniform and earlier crop maturity
  • Phosphorus(P) is an essential component of DNA the genetic material that allows plants to grow and reproduce
  • Phosphorus(P) is very important in the cell division and development of new tissues
  • Phosphorus(P) is a vital component of ATP the main energy-transfer compound which allows cells to conserve and use the energy released in metabolism
  • Phosphorus(P) stimulates root development

Symptoms of Phosphorus Deficiency

  • Stunted growth
  • Since phosphorus is mobile within the plant, deficiency symptoms appear on lower and older leaves first
  • Small leaves take on a reddish-purple tint leaf tips looks burnt and older leaves become almost black
  • Poor rooting

The role of Potassium in Crops

Potassium (K), along with nitrogen and phosphorus, is one of the three essential plant macronutrients and is taken up by crops from soils in relatively large amounts.

  • Potassium (K) increases resistance to diseases and low temperature
  • Potassium (K) increase plant vigor
  • Potassium (K) is involved in the movement of nutrient through plants
  • Potassium (K) is essential in sugar and starch formation.
  • Potassium (K) is known as the quality nutrient
  • Potassium (K) promotes a healthy roots system

Symptoms of Potassium Deficiency

Plants deficient in potassium ‘lodge’ or bend over at ground level making them difficult to harvest. Potassium deficiency makes a plant susceptible to disease.

  • Increase in the plant’s susceptibility to drought,lodging, and plant pathogens
  • Inter venial chlorosis (yellowing between the leaf veins)
  • Since potassium is mobile within the plant deficiency symptoms appear on lower and older leaves first
  • Older leaves look scorched around the edges and/or wilted.
  • Average nutrient content of common manures and fertilizers

You can have a look at the table given below it will an idea about the average nutrient content of common manures and fertilizers

 Material  Nutrient Content (%)
 N P2O5 K2O
Ammonium sulphate  20.5
Ammonium sulphate nitrate 26.0
Ammonium nitrate 33.5
Ammonium phosphate 20.0 20.0
Calcium ammonium nitrate 20.5 / 25.0
Nitrate of soda 16.5
Urea 46.0
Superphosphate (single) 18.0
Superphosphate (double) 35.0
Superphosphate (triple) 46.0
Mussooriephos 18-20
Rajphos 18-20
Muriate of Potash 50 / 60
Bone Meal 3.5 21.0
Fish meal 4.1 39 0.3-1.5
Poultry manure 1.2-1.5 1.4-1.8 0.8-0.9
Sheep manure 0.8-1.6 0.3-0.4 0.3-0.4
FYM 1.0 0.5 1.0
Compost 0.5 0.4 0.8
Groundnut cake 7.0 1.5 1.5
Castor cake 4.3 2.0 13
Neem cake 5.0 1.0 1.5
Gingelly cake 6.2 2.0 12
Coconut cake 3.0 1.9 1.8
KAU POP Recommendations Crops 2016
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