Nano fertilizers offer benefits in nutrition management through their strong potential to increase nutrient use efficiency. Traditional fertilizers are not only costly for the producer but may be harmful to humans and the environment. Furthermore, nano fertilizers may also be used for enhancing abiotic stress tolerance. This study was performed on the evaluation of nano chelated nitrogen and urea fertilizers on the physiological characteristics of wheat under drought stress conditions. Experiments were carried out in two locations in Fars province, Iran. The experimental design was performed as a split-split plot in RCBD design. The first factor included irrigation treatments (normal and withholding irrigation at the flowering stage), sub factor was nitrogen treatment (0, 37, 74 and 110 k g.ha-1) in the form of Urea fertilizer, and sub-sub factor was nitrogen (0, 14, 27 and 41 kg.ha-1) in the form of nano chelated nitrogen fertilizer. Studied traits were RWC, Ion Leakage, Protein, Phosphorus and Potassium content, Remobilization and photosynthesis rate. According to the analysis of variances, stress, nitrogen (urea) and nano chelated nitrogen had significant effects on all studied traits. Mean comparisons showed that drought stress led to 13% reduction in RWC, 21% Ion Leakage, 26% Protein, 13% Phosphorus and 26% Potassium content, 22% Remobilization and 69% photosynthesis rate compared to normal irrigation. In conclusion Application of 41 kg.ha-1 nano chelated nitrogen fertilizer in comparison with urea led to increase 4% in Rwc, 3% Ion leakage, 52% protein, 26% phosphor, 6% potassium, 6% Remobilization and 21% photosynthesis rate compared to control, respectively.

This study was performed to evaluation of nano chelated nitrogen and urea fertilizers on wheat plant under drought stress condition. Experiments were carried out in two locations in Fars province, Iran. Experimental design was performed as split-split plot in RCBD design. The first factor included irrigation treatments (normal and withholding irrigation at flowering stage), sub factor was nitrogen treatment (0, 37, 74 and 110 kg.ha -1 ) in the form of Urea fertilizer, and sub-sub factor was nitrogen (0, 14, 27 and 41 kg.ha -1 ) in the form of nano chelated nitrogen fertilizer. Studied traits included stem weight, spike weight, spike length, plant height, tiller number, stem diameter, anthocyanin, flavonoid, proline, soluble carbohydrates, chlorophyll a and b, carotenoid, 1000-seed weight, biological yield, seed yield and harvest index. According to analysis of variances, stress, nitrogen (urea) and nano chelated nitrogen had significant effects on all studied traits. According to mean comparisons, drought stress led to 51% reduction in seed yield compared to normal irrigation. Application of 37, 74 and 110 kg.ha -1 urea led to 9, 19 and 27% increase in seed yield compared to control, respectively. Application of 14, 27 and 41 kg.ha -1 nano fertilizer led to 31, 44 and 98% increase in seed yield compared to control, respectively. In interaction between stress, urea and nano fertilizer on seed yield, was found that at normal and stress condition the highest mean of seed yield (7591 and 4091 kg.ha -1 ) was obtained by 110 kg.ha -1 urea and 41 kg.ha -1 nano fertilizer. In conclusion replacing urea by nano chelated nitrogen can increase the yield even in the drought stress and decrease amount of needed fertilizer.