Nano-urea for Vegetable Cultivation in Coastal West Bengal

Nano-fertiliser has come up to curtail the use of inorganic fertilisers and to reduce the antagonistic effects of fertilizers on the environment. A field experiment was laid out under the randomised block design (RBD) in coastal West Bengal, India during kharif season of 2022 to examine the efficacy of IFFCO nano-urea in okra (Abelmoschus esculentus) cultivation. The treatments were T1 = no fertiliser; T2 = recommended fertiliser dose @ 90:45:45 kg ha-1:: N:P2O5:K2O; T3 = 1/3 N urea, PK + 1/3 N urea + 1/3 N nano-urea on equivalent basis (nano); T4 = 1/3 N urea, PK + 1/3 N nano + 1/3 N nano; T5 = 1/3 N nano, PK + 1/3 N nano + 1/3 N nano. Nitrogen was applied in three split doses whereas P and K were applied as basal. The plant vigour was recorded 50 days after sowing using Trimble Green Seeker. T2 and T3 recorded significantly higher normalised difference vegetation index (NDVI) values, and T1 recorded the lowest. Maximum okra yield was recorded in T2 whereas 44.7%, 18.5%, 38.1% and 41.2% yield reductions were recorded in T1, T3, T4, and T5, respectively. Fruit nitrogen content was also maximum in T2 (2.31% on a dry weight basis). The nitrate content in leachate was maximum in T2 (1.22 mg L-1) as compared to nano urea treated plots (0.74-0.85 mg L-1). The results of GHG measurement showed that the N2O emission decreased to 0.79-1.71 mg m-2 day-1 with nano-urea in comparison to 2.85 mg m-2 day-1 with conventional prilled urea. The field experiment showed that there was a yield penalty in case of nano-urea application but it has environmental benefits in terms of minimum nitrate level in leachate and low N2O emissions than the conventional urea application.