DAP fertilizer, NPK ratio, and Major types of fertilizers

Context:

Recently, Rajasthan continue of suffer an acute shortage of Di-ammonium phosphate (DAP) fertilizer, which has adversely affected the sowing of rabi crops, especially mustard and gram, in an estimated 50 lakh hectare area.

De-ammonium Phosphate Fertilizer (DAP):

• DAP is the second most commonly used fertilizers in India with its sales of 119.19 lakh tonnes in 2020-21.
• These fertilizers are applied just before or at the time of sowing as they are high in phosphorus (P) that stipulates root establishment and development – without which plants can't grow to their normal size or will take too long to nature.
• DAP consists of – 46% OF Phosphorus (P) and 18% of Nitrogen (N).
• Recently government announced a 137% increase in the subsidy on DAP from Rs. 511.55 to Rs. 1211.55 per 50 kg bag.
• The subsidy given on DAP is nutrient based subsidy whose rates vary across nutrients.

NPK ratio:

• The aim of Nutrient Based Subsidy Policy is to increase the consumption of P & K fertilizers so that an optimum balance of N:P:K = 4:2:1 can be achieved.
• There are 6 macro nutrients that are needed for well balanced growth of crops. These are –

• Nitrogen (N)
• Phosphorus (P)
• Potassium (K)
• Calcium (A)
• Magnesium (Mg)
• Sulphur (S)

• Nitrogenous fertilizers consist of Urea, Ammonium Nitrate, and Ammonium Sulphate.
• Potassic fertilizers consist of Potassium Nitrate, Chile Sulphate.
• Phosphatic fertilizers consist of Super Phosphate, Triple Phosphate.
• NPK ratio of 4:2:1 improves soil health and increase the yield of crops, resulting in enhanced income for the farmers.

Major types of fertilizers:

1. Neem Coated Urea: Urea is sprayed with neem oil for nitrification and inhibition properties.

• The coating of neem shows down the process of release of nitrogen from urea and there is an increase in nitrogen use efficiency.
• Neem Coate Urea increases the yield of paddy, sugarcane, maize, soybean, tur/Red gram.
• Urea has very high N and K content of 46% and 60% respectively which helps in improving soil health and growth of crops.

2. Primary fertilizers includes Nitrogen, Phosphorus, Potansium –

• Nitrogenous – Urea
• Phosphatic – Di-ammonium Phosphate
• Potassic – Muriate of Potash (MoP) fertilizers.

3. Secondary fertilizers include Calcium, Magnesium and Sulphur.

4. Some micronutrients include – Zinc, Iron, Boron, Chloride etc.