The effect of fertigation regimes on wheat grown in sandy soil was tested in two field experiments in Egypt. The aim of the study was to determine the vulnerability of wheat to extreme weather event under climate change scenarios. Eight fertigation treatments, in addition to farmer irrigation were tested. Two climate change scenarios obtained from Hadley climate change model were incorporated in CropSyst model to assess wheat yield responses to fertigation regimes under these scenarios. The results showed that the highest yield and the highest water use efficiency (WUE) was obtained under irrigation application using 1.2 and 0.8 of Etc, respectively, with fertigation application in 80% of application time in both growing seasons. The calibration of CropSyst model confirmed that the model is able to mimic the growth of wheat and predicted grain, biological yield, and WUE with high degree of accuracy. The highest yield reduction and the lowest WUE under the tested climate change scenarios were obtained from farmer irrigation. It can be concluded that irrigating wheat grown in sandy soil with an amount of either 1.0 or 0.8 of ETc with fertigation application in 80% of application time is recommended to enhance growth and yield, and to reduce wheat's damage caused by extreme climate change.

Drought is one of the major constraints for sustainable crop production worldwide, especially in arid and semiarid regions. The global warming and climate change scenario has worsened the dilemma of water scarcity, creating an immediate threat to food security. Conserving water resources and exploiting various strategies that enable plants to withstand water deficits need to be urgently addressed. Drought adversely affects plant growth by modulating a range of physio-chemical, metabolic, and molecular processes inside the plant body, which ultimately reduces crop productivity. Besides developing drought-tolerant cultivars, better nutrient management could be a promising strategy to enhance drought tolerance in crop plants. Silicon, a quasi-essential element, is known to play a vital role in improving crop performance under a range of biotic and abiotic stresses. This review discusses the potential of Si application in attenuating the adverse effects of water-deficit stress. Silicon enhances plant growth by improving seed germination, cell membrane stability, carbon assimilation, plant–water relations and osmotic adjustment (by accumulating soluble sugars, proline and glycine betaine). It triggers the activity of antioxidants, promotes the biosynthesis of phytohormones, enhances nutrient acquisition and regulates the activity of vital enzymes in plants under drought stress. Silicon also induces anatomical changes in the plant cell wall through the deposition of polymerized amorphous silica (SiO₂-nH₂O), thereby improving stem and leaf erectness and reducing lodging. Further, Si-mediated physiological, biochemical and molecular mechanisms associated with drought tolerance in plants and future research prospects have been elucidated.