In many regions of the world, including Egypt, water shortages threaten food production. An irrigation deficient strategy in dry areas has been widely investigated as a valuable and sustainable approach to production. In this study, the dry matter and grain yield of wheat was decreased by reducing the amount of irrigation water as well as the volume of the root system. As a result of this, there was an increase the soil moisture stress. This negatively affected the absorption of water and nutrients in the root zone of wheat plants, which ultimately had an effect on the dry matter and grain yield of wheat. The values of dry matter and grain yield of wheat increased with the ʻSakha 94ʼ variety compared to the ʻSakha 93ʼ class. It is possible that this was due to the increase in the genetic characteristic of the root size with the ʻSakha 94ʼ variety compared to the ʻSakha 93ʼ class, as this increase led to the absorption of water and nutrients from a larger volume of root spread. Despite being able to increase the water productivity of wheat by decreasing the amount of added irrigation water, the two highest grain yield values were achieved when adding 100% and 80% of irrigation requirements ( IR) needed to irrigate the wheat and no signif-icant differences between the yield values at 100% and 80% of IR were found. Therefore, in accordance with this study, the recommended irrigation for wheat is at 80% IR which will provide 20% IR. When comparing the water productivity of two wheat varieties in study, it becomes clear that ʻSakha 94ʼ was superior to ʻSakha 93ʼ when adding the same amount of irrigation water, and this resulted in increased wheat productivity for ʻSakha 94ʼ. The SALTMED results confirmed good accuracy (R2: 0.92 to 0.98) in simulating soil moisture, roots volume, water application efficiency, dry matter, and grain yield for two varieties of wheat under deficit irrigation conditions. Whilst using sprinkler irrigation system under sandy soils in Egypt.

FAO AquaCrop model ver. 6.1 was calibrated and validated by means of an independent data sets during the harvesting seasons of 2016/2017 and 2017/2018, at El Noubaria site in western north of Egypt. To assess the impact of the increase in temperature and CO2 concentration on potato biomass and tuber yield simulations, experiments were carried out with four downscaled and bias-corrected of General Circulation Models (GCMs) data sets based on the fifth phase of the Coupled Model Intercomparison Project (CMIP5) scenarios under demonstrative Concentration Trails (RCPs) 4.5 and 8.5, selected for 2021–2040 and 2041–2060. The study showed that the model could satisfactorily simulate potato canopy cover, biomass, harvest and soil water content under various irrigation treatments. The biomass and yield decreased for all GCMs in both future series 2030s and 2050s. Biomass reduction varied between 5.60 and 9.95%, while the reduction of the simulated yield varied between 3.53 and 7.96% for 2030. The lowest values of biomass and yield were achieved by HadGEM2-ES under RCP 8.5 with 27.213 and 20.409 Mg∙ha–1, respectively corresponding to –9.95 and –7.96% reduction. The lowest reductions were 5.60 and 3.53% for biomass and yield, respectively, obtained with MIROC5 under RCP 8.5 for 2030. Reductions in biomass and yield in 2050 were higher than in 2030. The results are showing that higher temperatures shortened the growing period based on calculated growing degree days (GDD). Therefore, it is very important to study changing sowing dates to alleviate the impact of climate change by using field trials, simulation and deep learning models.