How to make Urea more efficient as a fertilizer

TOPICS COVERED: Conservation, environmental pollution and degradation, environmental impact assessment.

Context:

Recently, Prime Minister of India officially launched ‘Urea Gold’ fertiliser.

What are fertilisers?

Any material of natural or synthetic origin mixed with soil or apply to plant tissues to provide plant nutrients is fertiliser.

Some of the fertilisers are urea, Di-ammonium phosphate(DAP) and Muriate of Potash.

About Urea Gold:

It is developed by the state-owned Rashtriya Chemicals and Fertilizers Ltd (RCF).
It is basically urea fortified with sulphur.
Normal urea contains 46% of a single plant nutrient: Nitrogen or N.
Urea Gold has 37% N plus 17% sulphur or S and aims at two things.
The first is to deliver S along with N.
Indian soils are deficient in S, which oilseeds and pulses – the country is significantly import-dependent in both – particularly require.
The second is to improve the nitrogen use efficiency (NUE) of urea.
Coating of S over urea ensures a more gradual release of N.
By prolonging the urea action, the plants stay greener for a longer time.
Farmers tend to apply urea when they notice the leaves turning yellowish.
If the crop retains greenness for an extended period, they would reduce the frequency of application and use.

The problem with urea:

Urea is India’s most widely used fertiliser.

There are two concerns over rising urea consumption.
The first is imports, which accounted for 7.6 mt out of the total 35.7 mt sold last fiscal.
Even with regard to domestically-manufactured urea, the feedstock used – natural gas – is mostly imported.
India’s nearly 36-mt annual consumption of urea is today next only to China’s 51 mt, with the latter’s production largely coal-based.
The second concern is NUE.
Barely 35% of the N applied through urea in India is actually utilised by crops to produce harvested yields.
The balance 65% N is unavailable to the plants, much of it lost through release into the atmosphere as ammonia gas or leaching below the ground after conversion into nitrate.
Declining NUE, from an estimated 48% in the early 1960s, has resulted in farmers applying more and more fertiliser for the same yield.

The solution: Urea Gold

India cannot sustain the above increase in consumption of urea – or even di-ammonium phosphate (DAP), muriate of potash and other fertilisers containing just primary nutrients: N, P (phosphorus) and K (potassium).
India hardly has any natural gas or rock phosphate, potash and sulphur reserves.
Hence it shouldn’t encourage the consumption of these commodity fertilisers.
Instead, they must be coated with secondary nutrients (S, calcium and magnesium) as well as micronutrients (zinc, boron, manganese, molybdenum, iron, copper and nickel).

Benefits of coating:

Coating allows urea or DAP to be used as “carrier products” for delivering secondary and micro nutrients to crops.
It improves their own N and P use efficiency through synergetic effects and controlled release.
In the case of urea, it helps reduce losses through ammonia volatilisation and nitrate leaching.

Consumption of fertilizer in India

India has consumed about 500 LMT of fertilizer over the last ten years.
Farmers prefer to use an excessive amount of urea as non-urea varieties such as MoP, DAP, and complex are relatively expensive.
Higher cost also leads to excessive use of urea and adverse impact on crops.
India is a major buyer of Diammonium Phosphate (DAP).
India is the second-largest consumer and the third-largest producer of urea in the world.
India consumes around 33 million tonnes of urea annually, of which almost 70% is domestically produced and the rest is imported from other countries.

Fertiliser subsidy by the government

The Agriculture sector in India accounts for 15% of the USD 2.7 trillion economy and over 60 per cent of the Indian population’s source of income comes from the sector.
To make fertilisers affordable to the farmers, the government of India pays a subsidy to fertiliser producers which allows farmers to buy fertilisers at below-market rates.
The government has taken numerous steps to reduce urea consumption by introducing neem-coated urea and also promoting organic and zero-budget farming.

Recent challenges

During the Covid-19 pandemic, China, the major exporter of fertiliser, reduced their exports due to a dip in production, which impacted India as the country was importing 40–45% of its phosphatic imports from China.
The ongoing war between Russia and Ukraine has also affected the global price as the supply of urea is derived from natural gas (Russia is the major supplier).
The demand for fertilisers has grown in different parts of the world including the US, Brazil and Europe.

What is a nano urea liquid?

Nano urea liquid is a nanotechnology-based fertilizer to increase the growth of crops by restoring nitrogen to plants as an alternative to conventional urea.
It enhances the nutritional quality and productivity of the crop along with improving the underground water quality.
The Indian Farmers Fertiliser Cooperative Limited (IFFCO), a cooperative society, has developed and patented nano urea liquid technology.
When sprayed on leaves, Nano Urea easily enters through stomata and other openings and is assimilated by the plant cells.
It is easily distributed through the phloem from the source to sink inside the plant as per its need.
Unutilised nitrogen is stored in the plant vacuole and is slowly released for proper growth and development of the plant.

Way forward:

The government currently permits coating of urea with zinc and sulphur.
Urea apart, an additional subsidy of Rs 300 and Rs 500 per tonne is being provided for P&K fertilisers fortified with boron and zinc, respectively.
These additional rates aren’t attractive enough for companies to market zincated urea, boronated DAP or any of the 20-odd fortified products recognised under the Fertiliser Control Order.
This is despite the proven benefits of micronutrient fortification.
For now, there’s not much incentive for fortification.
Ideally, the coating should be carried out at the factory itself, which will guarantee even more uniform distribution of micronutrients and save the farmer the hassles of mixing.
The government can probably set free the MRPs for all coated fertilisers.

SOURCE: THE HINDU, THE ECONOMIC TIMES, PIB

Post Views: 70