Is Nano Urea a Wonder Product To Dissolve the Fertiliser Subsidy Or Is More Validation Needed?

Agricultural scientists have concerns about a substitute for subsidised urea which the government is promoting to reduce the large subsidy bill. They say there is not enough publicly available information about the product, the effect it has on plant metabolism and its impact on human health and the environment. They question the yield claims made by the manufacturer and want the government to withhold large-scale rollout till studies establish the efficacy of the product beyond doubt.

In her interim budget speech on 1 February, Finance Minister Nirmala Sitharaman said Nano DAP would be promoted for use on a variety of crops in all agro-climatic zones after the “successful adoption” of Nano Urea. Nano urea is a patented product of IFFCO, a multi-state cooperative and India’s largest producer of fertilisers.

The Prime Minister approved Nano Urea in February 2021 and by 2023, the company would have the capacity to produce 170 million half-litre bottles of it, the Press Information Bureau (PIB) said in a release last April on the occasion of the Home Minister launching Nano DAP (Di-ammonium phosphate, another plant nutrient) in Delhi. The release added that Nano Urea was marketed from August 2021 and till last March, 63 million bottles of it had been produced. It asserted that 500 ml of the liquid containing four percent or 20 grams of nitrogen could replace a 45 kg bag of urea containing 20.7 kg of the nutrient.

Urea is sold at a cut price to farmers. A bag of 50 kg costs about Rs 1,600 while it is retailed to farmers at Rs 262. Farmers over apply the nutrient as other fertilisers, though subsidized, are very expensive. Subsidised urea is used not only by farmers. It is diverted for the production of wood adhesives and to hasten fermentation in distilleries. The government has tried to curb diversion from agriculture by coating urea granules with neem oil, but the oil is in short supply.

As Nano Urea is not subsidised, the government is keen to push it as the fertiliser subsidy bill is large. The revised estimate for this year is nearly Rs 1.9 trillion (lakh crore) or 4.2 percent of total central government expenditure. (It was Rs 2.5 trillion or nearly six percent of central government expenditure in 2022-23). The government has denied that it was anxious to put the product on the market and that it fast-forwarded the approval process. A PIB release of September 2022 said that the product has been provisionally notified under the Fertiliser Control Order on the basis of encouraging results from studies conducted over two seasons and feedback from scientists of the Indian Council of Agricultural Research (ICAR) and state agricultural universities. The release said application of Nano Urea on crops during critical growth stages resulted in 3-23 percent increase in the yield of wheat, 5-11 percent higher tomato production, 3-24 percent rise in the output of paddy and 2-15 percent more maize. Such a payback was also seen in cucumber and capsicum.

Iffco’s website has details of Nano Urea trials on crops planted since the winter of 2019-20 in 27 states and one union territory. The 13,892 trials show an average yield increase of 6.90 percent over crops in farmers’ plots where the product was not used. The results of crop-wise trials and the names of the farmers on whose plots the trials were conducted are also mentioned. The company says the product has been tested for bio-safety in credible laboratories.

As per Iffco, if base dose of granular urea is applied, 500 ml of Nano Urea sprayed in two stages about four weeks after germination and again three weeks after the first application, can replace one bag of granular urea in one acre.  

Karnal-based agricultural scientist Virender Latther, who was earlier with the Indian Agricultural Research Institute (IARI) is incredulous. He wonders how a mere change of form and mode of application can result in 20 grams of nitrogen in NU replacing 20.3 kg of the nutrient applied to soil as urea prills. It is an established science, he says, that 20 kg of nitrogen is needed to produce one tonne of wheat or paddy. Nano urea, as per the cooperative, is urea dispersed in liquid as particles of 20-50 nanometres (one nanometer is 100 millionth of a metre) in an organic casing. Since the particles are miniscule, they have a larger surface area, and are better absorbed. But Latther says even if there is 100 percent absorption, crops cannot maintain the yields. He suspects that they are mining nitrogen reserves in soil, and continued substitution granular urea with Nano Urea will result in yields tapering and soil nitrogen depleting.  

A study done by soil scientist Rajeev Sikka and his team at Punjab Agricultural University (PAU) does not support Iffco’s claims. As per the study which is available on the internet, the team followed Iffco’s protocol and grew rice with 50 percent of the recommended dose of nitrogen and two foliar sprays of 500 ml Nano Urea in 2020 and 2021. The grain yield was lower by 17 percent and nine percent in the two years. There was also a decline in the protein content. PAU’s Vice-Chancellor Satbir Singh Gosal declined to comment. He said Nano Urea was “under experimentation” and he would wait “till final results are available.”

Scientists at IARI, New Delhi did studies of Nano Urea on rice-wheat and pearl millet-mustard systems with zero, 50 percent, 75 percent and 100 percent of the recommended dose of granular urea. (The study was funded by Iffco, but the researchers say they followed an independent methodology).  The required amount of potassium and phosphorous was also applied. As per the published study, wheat and mustard yields were maintained when 75 percent of the recommended dose of nitrogen was given in granular form in the first year. But yields declined “significantly” in the second year. Yields also declined “significantly” when the Iffco protocol of 50 percent granular urea and two nano sprays was followed. Nevertheless, the study team went on to recommend Nano Urea application with 75 percent urea for wheat, pearl millet, maize and mustard. This would result in a huge saving of subsidized urea, it said. While asserting that Nano Urea could bring about a “paradigm shift in the fertilizer consumption scenario,” it called for the findings to be validated across crops before any policy decision was made.

But the authors of another study - Max Frank and Soren Husted - in the journal Plant Soil are not as circumspect. They said Nano Urea is a “poorly described product with no scientifically proven effects.” The product is marketed with misleading and wrong statements about fertiliser efficiency, the underlying plant uptake pathways and environment friendliness. The expectation raised by the manufacturer were far from reality, they said, and may lead to large-scale yield losses with serious consequences for food security and the livelihood of farmers.

If Nano Urea is a wonder product, farmers would not need persuasion to buy it. But there are news reports of Haryana farmers protesting against vendors forcing Nano Urea on them. Last month, the agriculture department in Karnal issued an order prohibiting the tagging of Nano Urea and insecticides sales with that of granular urea.