Nano urea (a fertilizer) has been approved for commercial use by the government, but many experts have questioned the science underlying its efficacy.
what is nano urea
This is urea in the form of a nanoparticle. It is a nutrient (liquid) providing nitrogen to plants as an alternative to conventional urea. Urea is a white colored chemical nitrogen fertilizer that artificially provides nitrogen, a key nutrient needed by plants.
Why do farmers choose Nanoria?
It has been developed to replace conventional urea and can reduce its requirement by at least 50%. This allows for greater absorption than conventional urea because it contains nanoparticles which are consequently more absorbed by plants.
The small size (20-50 nm) of nano urea increases its availability for the crop by more than 80%.
How does Nano Urea work?
“When sprayed on leaves”, “nano urea easily penetrates through stomata and other pores” and “is assimilated by plant cells”. It is easily distributed from the source through the phloem for sinking inside the plant as per its requirement. The unused nitrogen is stored in the plant vacuole and slowly released for proper growth and development of the plant.
Why have experts questioned the effectiveness of nano urea?
Discrepancy in percentage of available nitrogen: Chemically packaged urea contains 46% nitrogen, which means that a 45 kg sack contains about 20 kg nitrogen. In contrast, nano urea, sold in 500 ml bottles, contains only 4% nitrogen (or about 20 g). This discrepancy in the percentage of available nitrogen has puzzled many experts.
The effectiveness of nitrogen absorption is questionable: urea is highly water soluble and reaches its lowest form of concentration when already absorbed. Foliar spraying to improve fertilizer uptake has been known for more than half a century.
Even if 100% of 20 grams of nano urea, which is effectively available, is used by the plant, it will yield only 368 grams of grain. Hence, “the total effort is in vain due to sheer waste of money”.
argument in opposition When conventional forms of urea fall on the soil, all the nitrogen present in that grain, usually 1–2 mm in size, becomes readily available to the crop. But due to bursting, ammonia escapes into the environment, reacts with oxygen in the atmosphere, and becomes nitrous oxide which is a greenhouse gas.