Impact of Irrigation Schedules and Nano Urea on Nutrient Content and Uptake of Maize

Abstract

Maize productivity and nutrient acquisition are strongly influenced by water and nitrogen management. A field experiment was conducted during the 2022–2023 rabi season at the Instructional-cum-Research Farm of Assam Agricultural University, Jorhat, to evaluate the individual and interactive effects of irrigation schedules and nano-urea-based nitrogen management on nutrient content and uptake in maize kernel and stover. The split-plot experiment comprised four irrigation schedules as main-plot treatments and three nitrogen-management practices as subplot treatments. Irrigation at the grand-growth, tasselling and grain-filling stages recorded the highest N, P and K contents and uptake in the kernel and stover and was statistically at par with irrigation at an IW/CPE ratio of 0.8. Among nitrogen treatments, 50% recommended dose of nitrogen applied as basal urea together with foliar sprays of nano urea at 6 mL L⁻¹ at the knee-high and tasselling stages produced the highest nutrient content and uptake and was statistically comparable with the corresponding 4 mL L⁻¹ treatment. Kernel protein content was also highest under the 6 mL L⁻¹ treatment. Significant irrigation × nitrogen-management interactions were observed for N uptake by the kernel and P uptake by the stover, with the I₄N₃ combination recording the highest values. The lowest nutrient content and uptake were observed under rainfed conditions and irrigation at an IW/CPE ratio of 0.6. The findings indicate that appropriately timed irrigation combined with reduced basal urea and foliar nano urea may support nutrient acquisition in rabi maize under the study conditions.