Context: A two-year field experiment on the efficacy of nano urea has found a substantial decrease in Crop yields when compared to conventional nitrogen (N) fertilizer application. 

• A two-year field experiment on the efficacy of nano urea by scientists from Punjab Agricultural University (PAU) has found a substantial decrease in rice and wheat yields when compared to conventional nitrogen (N) fertilizer application. 

Key Findings on Efficacy of Liquid Nano Urea

• Decline in Yield: There was a 21.6 percent decrease in wheat yield and a 13 percent decrease in rice yields with nano urea. 
• Decrease in Grain Content: There was a 17 and 11.5 per cent decrease in grain N content of rice and wheat, respectively, with the combined application of nano urea and N to  soil. 
  • A decrease in grain N content reflected a lowered protein content. 
• Conventional Urea more efficient: According to the report, even if 100 per cent use efficiency is achieved by this nano formulation, the requisite nitrogen nutrient could not be provided to the growing crop compared to nitrogen provided by 45 kg of conventional urea
• Higher Cost: The cost of nano urea formulation was 10 times higher than that of granular urea and added to the cost of cultivation for farmers. 
• Decrease in Ground Mass and Root Volume: The PAU field experiments also revealed that the above ground biomass and root volume were reduced after nano urea application, thus resulting in less root biomass addition after the crop harvest.
  • The lower root volume indicated a decreased available root-surface area that can culminate to lowered N and other nutrient uptake processes by the root. 

News Source: DTE