Response of Sweet Corn to Nano Urea under Precision Nitrogen Management

A lack of synchronization between nitrogen (N) demand and supply results in the loss of applied nitrogen from the soil-plant system. Leaf colour chart (LCC) based nano urea application according to crop specific need has the potential to enhance the crop productivity by reducing N losses. In this context, a field experiment was conducted during summer seasons of 2022 and 2023 on medium black calcareous soil at Junagadh (Gujarat) to study the response of sweet corn to nano urea under precision nitrogen management. Ten treatments comprising 40 kg N as basal (through DAP and urea) + 40 kg N through urea at 25-30 DAS + 40 kg N through urea at 40-45 DAS, 40 kg N as basal + 40 kg N through urea at 25-30 DAS + two foliar spray of nano urea 0.4% (4 ml/l water) when LCC ≤ 4, 40 kg N as basal + 30 kg N through urea at 25-30 DAS + three foliar spray of nano urea 0.4% when LCC ≤ 4, 40 kg N as basal + 20 kg N through urea at 25-30 DAS + four foliar spray of nano urea 0.4% when LCC ≤ 4, 40 kg N as basal + 20 kg N through urea at 25-30 DAS + three foliar spray of nano urea 0.4% when LCC ≤ 4, 40 kg N as basal + 10 kg N through urea at 25-30 DAS + four foliar spray of nano urea 0.4% when LCC ≤ 4, 40 kg N as basal + 10 kg N through urea at 25-30 DAS + three foliar spray of nano urea 0.4% when LCC ≤ 4, 40 kg N as basal + four foliar spray of nano urea 0.4% when LCC ≤ 4, 40 kg N as basal + three foliar spray of nano urea 0.4% when LCC ≤ 4 and control (without N application) in Randomized Block Design with three replications. Based on the results of two-years field study, it can be concluded that higher growth, green cob and fodder yields, quality, net returns and B: C ratio of sweet corn can be obtained by the application of 40 kg N as basal + 40 kg N through urea at 25-30 DAS + two foliar spray of nano urea 0.4% when LCC ≤ 4 or 40 kg N as basal + 30 kg N through urea at 25-30 DAS + three foliar spray of nano urea 0.4% when LCC ≤ 4 or 40 kg N as basal + 40 kg N through urea at 25-30 DAS + 40 kg N through urea at 40-45 DAS.