 "fertilisers, farming, farmers, farm ,agriculture")
Intensive agriculture with high-yielding variety seeds requires the application of plant nutrients through chemical fertilisers. Nitrogen, phosphorous and potash are three primary nutrients. Then there are secondary nutrients like calcium and sulphur and a large number of micronutrients like zinc, boron, iron and selenium. While all the nutrients are important for maximising yield and quality of products, nitrogen remains the single most important nutrient. Its application in adequate quantity along with other nutrients is an integral part of a nutrient management system. The drawback with nitrogen application is that its uptake by the crop is limited and balance is quickly lost to the environment. Nitrogen use efficiency is low in India, typically 35-40 per cent, compared to as high as 80 per cent elsewhere in the world. Nitrogen not used by the crop escapes to the environment, both water and air. In the air, the greenhouse effect of nitrogen oxide is few hundred times more than carbon dioxide. It also causes nitrate pollution of ground and surface waters.
Nitrogen use efficiency (NUE) depends on the type of product and timing and manner of application. About 80 per cent of nitrogen application in India takes place through urea. In 2015, the government made it mandatory to coat urea with neem oil. The move was expected to increase the use efficiency compared to uncoated urea. In the first few years of the introduction of neem-coated urea (NCU), growth in urea consumption slowed down. It picked up again and the use of urea increased from 29.9 million tonnes in 2017-18 to 35.7 million tonnes in 2022-23. The overriding factor remains a stagnant retail price of urea at a very low level. Urea is sold to the farmers at only about 20 per cent of its cost of production or import. This encourages farmers to use more urea compared to other plant nutrients. This imbalanced use of nutrients is also one of the causes of low NUE.
The government has initiated action on several fronts to limit the use of urea. One of the schemes initiated last year was PM-PRANAM. The scheme incentivised states to reduce the use of chemical fertilisers through the provision that any savings in fertiliser subsidy will be shared with the states.
The government has now taken the initiative to nudge the industry to produce and sell sulphur-coated urea (SCU). The underlined objective is twofold. One is to make urea a slow-release fertiliser that improves the nitrogen uptake by crops significantly and hence results in higher nitrogen-use efficiency. Some field experiments have shown that nitrogen use efficiency can be increased by 10-15 percentage points. The second part of the objective is to provide sulphur application simultaneously in deficient soils. Specifically, oil seeds and pulses require more sulphur. The area under oil seeds and pulses was 30.92 and 26.34 million hectares respectively in 2020-21. Fertilisers like single super phosphate, ammonium sulphate and ammonium phosphate sulphate meet the requirement of sulphur in Indian agriculture. There is also some direct application of sulphur as Bentonite Sulphur.
Given these advantages, the production and use of sulphur-coated urea have a distinct advantage over ordinary urea. However, it has to be applied by the farmers as per recommendations for specific coops and agroclimatic conditions. There are also challenges in producing sulphur-coated urea with prilled Urea as the starting material. Granulated urea is the preferred material for coating of sulphur. However, only prilled urea is produced in India. There will also be off-specification SCU which has to be gainfully utilized. These challenges both in production and use can be overcome with proper planning, appropriate application of technology and enabling policy. For example, off-specification products can be utilised as input in the production of complex fertilizers.
The real challenge is on the policy front. As mentioned, urea remains a very cheap input for the farmers. Therefore, SCU has to be competitively priced to encourage the farmers to switch from ordinary urea. The government has mandated that SCU will be sold in 40 kg bags and the selling price will be the same as for a 45 kg bag of ordinary urea. The specification of SCU includes 37 per cent nitrogen and 17 per cent sulphur. Ordinary urea has 46 per cent nitrogen. Thus, SCU has about 20 per cent lower nitrogen content than ordinary urea. Better nitrogen-use efficiency should largely compensate for lower application of nitrogen based on the same number of bags per hectare. However, there have to be field trials to demonstrate that lower application of nitrogen does not affect crop yields. Excess use of SCU will also harm the soil. Therefore, it will require efforts on the part of the extension machinery of states and fertiliser manufacturers for not only penetration of this new product but also to ensure appropriate use to fulfill its objectives.
The second part of the challenge is that it should be remunerative for the industry to produce and sell. In addition to the cost of sulphur, there will be additional operational costs. Capital investment in coating plants and sulphur facilities will also have to be serviced. If the compensation in addition to normal subsidy on urea falls short, the new product will remain a non-starter.
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In conclusion, farmers need to be educated to adopt the use of SCU most appropriately and manufacturers need to be sufficiently incentivized. Any replacement of regular urea with SCU will not only save urea from the present level of application, it will also help to avoid leakage of active nitrogen to the environment.
The writer is ex-ADG Fertiliser Association of India
These are the personal opinions of the writer. They do not necessarily reflect the views of business-standard.com or the 'Business Standard' newspaper
