Efficient nitrogen management in wheat through a combination of conventional and nano urea with optimized methods and timing

The rice-wheat cropping system is the largest cereal-based agricultural production system in India. It provides considerable significance to national food, nutrition, and livelihood security. However, the extensive use of resources under rice-wheat system has resulted in significant issues, including a decline in groundwater levels, indiscriminate use of fertilizers, the burning of rice residues, increased emissions of greenhouse gases, and the development of herbicide-resistant weeds which led to stagnant crop productivity and reduced profitability. This study was conducted at the research farm of ICAR-IIWBR, Karnal, India, to evaluate the combined effects of conventional and nano urea on productivity, profitability, and efficient nitrogen management strategy in wheat under rice-wheat system. The study evaluated eight treatment combinations of nitrogen application through conventionally applied urea (46% N) and foliar applied nano urea (4% N). The results of the study showed that the application of 150 kg N/ha in three equal splits as basal and just before 1st and 2nd irrigation, either alone (T2) or along with a spray of nano urea (T5), resulted in the highest grain yield and profitability. Top dressing of urea just before irrigation with a dose of nitrogen 150 kg/ha applied in three equal splits (T2) resulted in 420 kg/ha additional grain yield over top dressing at 7-10 days after irrigation with same dose (T3). Treatment T5 recorded the highest gross and net returns with 2492.5 and 1804.0 US $/ha. The study's findings suggest that efficient nitrogen management is essential for sustainable wheat production in India. The application of 150 kg N/ha in three equal splits, either alone or along with a spray of nano urea, is a promising strategy for improving wheat productivity and profitability in India.