Two ‘small is powerful’ ideas share the latest issue of ICAR’s farm magazine. Seedling greens are a sound, modest addition to diets and incomes. Liquid nano-urea, promoted as a replacement for the urea bag, faces unresolved questions from independent field trials.
The Indian Council of Agricultural Research’s magazine Indian Farming gives pride of place in a recent issue to two technologies united by scale. One is biological: microgreens, vegetables harvested as seedlings. The other is chemical: nano-urea, a liquid nitrogen fertiliser sprayed on leaves. Both are presented as answers to large problems, malnutrition in one case and fertiliser overuse in the other. They are at very different stages of scientific confidence, and it is worth treating them separately.
Microgreens: what they are
Microgreens are the young shoots of vegetables, herbs and grains, cut when the first true leaves appear, typically 7 to 21 days after sowing. They are older than sprouts, which are eaten root and all after a few days in water, and younger than baby leaf salad. Mustard, radish, fenugreek, amaranth, beetroot, red cabbage, broccoli, coriander and sunflower are common choices.
The nutritional claim has a respectable basis. A much-cited study by researchers at the University of Maryland and the United States Department of Agriculture in 2012 analysed 25 commercially grown microgreens and found that concentrations of vitamins and carotenoids were generally several times higher than in the mature leaves of the same plants, by a factor of 4 to 40 depending on the nutrient and species.
Two qualifications apply. The comparison is weight for weight, and a serving of microgreens is a garnish of 20 or 30 grams, not a bowl of cooked spinach. They complement leafy vegetables in the diet; they do not replace them. And few trials have measured health outcomes in people, as distinct from nutrient content in leaves.
A crop for small spaces
The agronomic attraction is that microgreens need almost nothing: a shallow tray, a growing medium such as cocopeat, seed, clean water and indirect light. There is no fertiliser or pesticide in a crop cycle of two weeks. A balcony or a spare room suffices, which makes them suited to urban households, women’s self-help groups and landless families, and to schools seeking to improve midday meals.
As an enterprise, they fetch high prices from restaurants and premium retailers, but the market is narrow and the product perishes within days. Seed is the main cost and must be untreated, since fungicide-coated seed intended for field sowing is unsafe for a crop eaten whole. Hygiene matters: warm, humid trays can harbour bacteria, and growers need the same care over water quality and handling as any producer of ready-to-eat food. With those cautions, the case for microgreens is sound and proportionate.
Nano-urea: the promise
Nano-urea is a far bigger proposition. India consumes well over 350 lakh tonnes of urea a year, imports a significant share, and spends heavily on subsidy. Much of the nitrogen applied to soil never reaches the crop; it escapes as ammonia and nitrous oxide or leaches into groundwater as nitrate. A product that delivered nitrogen more efficiently would save money and reduce pollution.
The Indian Farmers Fertiliser Cooperative, IFFCO, introduced liquid nano-urea in 2021 and opened its first dedicated plant at Kalol in Gujarat in May 2022. The product consists of nitrogen-containing particles of nanometre size suspended in water, sprayed on the crop canopy at key growth stages. The claim made at launch was that a 500-millilitre bottle could substitute for a full bag of conventional urea. The recommended practice was to halve the urea top-dressing and replace it with sprays. IFFCO cites trials at thousands of farm sites and with ICAR institutes showing maintained or slightly higher yields.
The evidence gap
Independent results have been less favourable. A two-year field experiment at Punjab Agricultural University, following the recommended protocol on rice and wheat, reported significantly lower grain yields than with the full dose of conventional urea: about 13 per cent lower in rice and, depending on the report, 17 to 22 per cent lower in wheat, along with reduced grain protein. A 2025 study in the Indo-Gangetic plains likewise found that wheat yields under nano-urea combinations remained below those under the full recommended fertiliser dose, while noting improved nitrogen-use efficiency.
Plant nutrition scientists abroad have raised a more basic objection. A bottle of the original formulation contains only about 20 grams of nitrogen, against more than 20 kilograms in the bag it was said to replace. No known mechanism of leaf uptake, they argue, could make up a thousandfold difference. A wheat crop that yields five tonnes removes over a hundred kilograms of nitrogen per hectare, and that nitrogen has to come from somewhere.
Policy has begun to respond. A parliamentary committee has called for close audit of field trials and long-term effects. In February 2026 the government told Parliament that manufacturers of nano-fertilisers would be required to conduct bio-efficacy trials across agro-climatic zones. A fertiliser control order amendment in March 2026 reduced the proportion of the conventional dose that nano products may be recommended to replace, according to a detailed report in Business Today.
How to read the two stories
The fair conclusion is that nano-urea may have a role as a supplementary foliar feed, particularly for a late top-up when soil application is impractical. Foliar urea sprays have long been used that way. What has not been demonstrated to the satisfaction of independent agronomists is that it can replace a substantial part of soil-applied nitrogen without loss of yield.
The science of nano-enabled fertilisers is legitimate and active worldwide: coatings and carriers that release nutrients slowly are a promising route to efficiency. Credibility depends on publishing multi-season, multi-location data, with full-dose controls, in peer-reviewed form.
Until then, the proven routes to using less urea remain unglamorous: soil testing, split application, neem-coated urea, leaf colour charts, placement below the surface, and legumes in the rotation. Microgreens, by contrast, ask little and promise little, and deliver what they promise. In agriculture, as elsewhere, the size of a claim should match the size of the evidence.
– Naresh T
