Energetic assessment of summer maize cultivation under nano zinc oxide and drip irrigation

The current study conducted in summer season of two consecutive year i.e., 2022 and 2023 at Agricultural Farm, Palli Siksha Bhavana, Visva-Bharati, West Bengal with the aim to investigate the effect of nano zinc oxide on energetics of summer maize under and micro irrigation. A split-plot design with three replications was used, where irrigation treatments were assigned in main plots and zinc oxide treatments were assigned in subplots, respectively. In main plot four drip irrigation treatments viz., drip irrigation Once-in-2-days, Once-in-3-days, Once-in-4-days and surface flooding irrigation were accommodated. The sub plot treatments consist of five biofortification of nano zinc oxide treatments viz., No zinc application or control, soil application of ZnSO₄ at 20 kg ha^-1, foliar application of nano ZnO at 40 ppm, seed priming of nano ZnO at 40 ppm, and seed coating of nano ZnO at 40 ppm. Result revealed that energy input recorded more in surface flood irrigation among all the irrigation treatments and among zinc application methods more energy input recorded in soil application of zinc sulphate at 20 kg ha^-1. Energy output in grain yield, energy output in stover yield, total output energy, net energy, energy efficiency ratio, energy productivity observed highest with the application of water through drip once-in-2 days and lowest in the surface flooding irrigation whereas among different zinc application methods the seed coating of nano zinc oxide at 40 ppm exhibited highest value and the treatment seed priming of nano zinc oxide at 40 ppm was on par in case of energy output in grain yield, energy efficiency ratio and energy productivity. Energy intensity in physical term did not any significant differences in both drip irrigation scheduling and different zinc application methods. Based on PCA analysis, results indicated that energy output by grain, energy efficiency ratio, and energy productivity correlated significantly and positively with the first axis, whereas energy intensity in physical term correlated significantly and positively with the second axis.