Nano-fertilizers improved drought tolerance in wheat under deficit irrigation

Although, the deficit irrigation saves the water consumption, but it may cause the loss of yield. Recently, the nano-fertilizers have been used in the agriculture as an approach to minimize the adverse effects of drought stress. Thus, in this study, a two-year (2016/2017 and 2017/2018 winter wheat seasons) split-plot field experiment was conducted to investigate the effect of the nano-chelating fertilizers on the yield and water use efficiency of the wheat with three replications in Iran. The main plots consisted of full and deficit irrigation (50% of full irrigation requirement), and the subplots included foliar spraying with nano chelated -Silicon, -Boron, and -Zinc fertilizers and control. The total irrigation water was equal to 457 and 228 mm for full and deficit irrigation, respectively for the first year, and it was equal to 378 and 190 mm, respectively for the second year. Deficit irrigation significantly decreased the yield components, relative water content (RWC), and cell membrane stability index (CMSI) leading to reduction of the grain yield by 43%, but it increased the grain protein, WUE, and superoxide dismutase (SOD) and catalase (CAT) activities. Nano-zinc increased the protein percentage of wheat grain in both years and irrigation regimes. The activity of SOD and CAT was improved especially in the deficit -irrigated plants and also the yield, yield components, RWC, and CMSI of wheat by applying the nano-fertilizers under both irrigation conditions. Nano-silica application under deficit irrigation in both years resulted in 28% and 32% increase in the grain yield, respectively, compared to the control. The highest WUE was obtained using the nano-silica under deficit irrigation condition in both experiments. Generally, the results indicated the considerable importance of the nano-silica fertilizer in reducing the damage caused by the deficit irrigation and improving the growth characteristics of the wheat.