Worsening nutrient imbalance due to urea and DAP

The easing of global prices has boosted fertiliser availability and cut the subsidy bill. However, asymmetry in the pricing structure has led to a worsening nutrient imbalance due to the over-application of urea and DAP.

Background:

• The year 2022 saw global prices of fertilisers go high due to the post-Russiainvasion of Ukraine in February.
• Landed prices of urea imported into India (cost plus freight) are ruling at around $550 per tonne, as against $900-1,000 average in November-January 2021-22, when global demand for food and plant nutrients surged with the lifting of Covid lockdowns by most countries.
• The United Nations Food and Agriculture Organisation’s Food Price Indexhit 159.7 points in March 2022.
• From that all-time high, the index — which is a weighted average of global prices of a representative basket of food commodities over a base period value, taken at 100 for 2014-2016 — has fallen for nine consecutive months.
• However, till December 2022 a number of 132.4 points was below even the year-ago value of 133.7 points and the lowest since the 129.2 points of September 2021.
  
  

About Di-ammonium Phosphate (DAP):

• It is a very popular fertilizer because of its excellent physical properties and nutrient content.
• It is free-flowing, dust-free and does not normally give any storage problems.
• DAP is almost water-soluble and ultimately leaves an acid effect on soils because of the ammonia (NH4) it contains.
• DAP on incorporation into soil reacts with water and gets converted into HPO4 and NH4.
  • Ammonium (NH4) follows the same routes as in the case of urea.
  • Phosphorus in DAP is present in the best available form (HPO4).
• Depending upon the soil reaction (pH),phosphorus exists in 3 forms which can be absorbed by plant roots.
• These are HPO4, H2PO4 and PO4. Phosphorus, which is immobile in the soil, is not subjected to leaching losses.

Reasons behind increased consumption of urea and DAP:

• High subsidy on urea: The government has fixed the maximum retail price (MRP) of urea at Rs.5,628 per tonne, while the MRPs of other fertilisers are technically decontrolled.
• DAP – a cheaper substitute: Companies have been told not to charge more than Rs.27,000/tonne for DAP (Rs.29,000-31,000/ tonne for NPKS complexes), which has 46% P and 18% N.
• Thus, the choice of fertilisers is primarily a function of prices and not of NPKS complexes or other macro and micronutrients in the fertilisers.

What are the impacts of global ease on the prices of fertilisers?

• It significantly improves overall availability. No major shortage of any fertiliser, except MOP, has been reported during the on-going Rabi cropping season.
• Reduction in fertiliser subsidy of the government.

Challenges emerged:

• Over-use of fertilisers: India’s fertiliser sector has been riddled with distortions from excessive use of urea. The diammonium phosphate or DAP is seeing a similar phenomenon of over-application due to under-pricing. The effects of overconsumption of urea and DAP:
  • The current NPK ratio of 13:5:1, as against the ideal 4:2:1, would adversely affect crop yields
  • It will adversely affect the health of plants and humans, due to the unavailability of a balanced nutrient mix.
• Increase in Urea consumption: Urea has 46% nitrogen (N), while DAP contains 46% phosphorus (P) plus 18% N and MOP has 60% potassium (K).
• Neem oil supposedly also acted as a mild nitrification inhibitor, allowing a more gradual release of nitrogen. Increased nitrogen use efficiency would, in turn, bring down the number of urea bags required per acre.
• Worsening of nutrition imbalances:The consumption of both urea and DAP has shot up, with their sales for the year ending March 2023 likely to top 350 lt and 120 lt respectively.

Suggestive measures:

• To restrict DAP used to rice and wheat.
  • The danger is of even this well-accepted fertiliser loses out to DAP because of flawed pricing.
• To raise SSP’s acceptance by permitting sale only in granular, not powdered, form.
  • SSP powder is prone to adulteration with gypsum or clay.
  • Farmers can be assured of quality through granules, which will also promote a slower release of P without drift during application.