Synergistic impact of nano-urea and microbial inoculants with varied nitrogen regimes on the yield and yield attributes of hybrid maize (Zea mays L.)

Maize, a crucial cereal crop in India, faces challenges like limited land and climate change. Fertilizers like nitrogen, phosphorus, and potassium are essential for crop yields, but excessive use can cause eutrophication and nitrate pollution. Researchers are exploring slow-release fertilizers and nanotechnology-based solutions to improve nitrogen uptake efficiency. Slow-release fertilizers maintain nitrogen availability and control nitrification processes, while nanotechnology-based fertilizers release nitrogen only when needed, reducing emissions and leaching. Microorganisms like azophos can fix nitrogen, facilitate phosphorus uptake, and produce growth-promoting chemicals. The use of nano urea and beneficial microorganisms like azophos can boost maize production and yield. To investigate further, a field experiment was conducted at the Experimental Farm, Department of Agronomy, Annamalai University, Annamalai Nagar, Cuddalore district of Tamil Nadu from July to October 2022 with a key objective of evaluating the partial supplement of different levels of nitrogen fertilizer in the form of conventional urea and nano urea along with the microbial inoculant azophos in hybrid maize (Zea mays L.). The experiment was laid out in randomized block design with ten treatments comprised of different levels of urea and nano urea along with azophos @ 4kg/ha with three replications. Among the nutrient management evaluated, all the yield attributes and yield of hybrid maize viz., cob length, cob diameter, number of grains/cob, test weight, grain yield, stover yield, and harvest index were significantly influenced by theapplication of 50 percent RDN through urea + 50 per cent RDN through nano urea + 100 percent RD of P and K through conventional fertilizers + azophos @ 4 kg/ha (T8). Combining bulk urea and nano urea improved nitrogen use efficiency via metabolite production, enzyme activity stimulation, and microbial rhizosphere interactions significantly enhancing the yield attributes and yield.