Enhancing saline water productivity in arid regions is essential for sustainable agriculture. Adding biochar can improve the quantity and quality of tomato yield under higher levels of salinity and lower levels of irrigation. The experiment aimed to evaluate the effects of biochar on enhancing tomato fruit quality and yield under salinity and drought stress. The experiment combines two treatments for irrigation water quality (0.9 and 2.3 dS m⁻¹), four irrigation levels (40, 60, 80, and 100%) of crop evapotranspiration (ETc), and the addition of 5% of biochar to treated soil (BC_5%) and untreated soil (BC_0%). The results showed that the decrease in the water quality and irrigation levels negatively impacted the yield and properties of tomato fruit, while 5% of biochar application positively improved the yield. Adding biochar decreased the tomato yield by 29.33% and 42.51% under lower-saline-irrigation water than the control, negatively affecting the fruit’s physical parameters and mineral content. In contrast, adding biochar and irrigating with saline water at 60% of ETc improved the firmness and quality characteristics of the fruit by 56.60%, 67.19, 99.75, and 73.57% for vitamin C (VC), total titratable acidity (TA), total soluble solids (TSS), and total sugars (TS), respectively, compared to the control, and also reduced the sodium content of the fruits under all irrigation levels compared to untreated plants by biochar. Generally, biochar with saline water under deficit irrigation with 80 and 60% of ETc could be an excellent strategy to enhance the qualitative characteristics of tomato fruits and save approximately 20–40% of the applied water.

This study aims to evaluate the Partial Root Zone Drying Irrigation System (PRD) as one of the modern technologies that provide irrigation water and increase the efficiency of its use on potato crop. The effect of applying the PRD conventional deficit irrigation (CDI) on the efficiency and water saving in potato crops using the drip surface (S) and subsurface (SS) irrigation methods were investigated. SALTMED model used to predict soil moisture and salinity distribution, soil nitrogen dynamics, and yield of potato crop using the different irrigation levels (150%, 100%, and 50% of Crop evapotranspiration (ETc)). The study showed that the water use efficiency (WUE) decreases with increasing levels of irrigation water, as it ranged between 2.96 and 8.38 kgm⁻³, 2.77 and 7.01 kgm⁻³ for surface irrigation PRD and CDI, respectively, when the amounts of irrigation water varied from 308 mm to 1174 mm, respectively. The study showed that the irrigation efficiencies were the highest when using PRD system in all treatments when irrigating the potato crop during the spring season, and it was more efficient in the case of using subsurface irrigation method. The results show that the soil moisture (SM) was high in 25–45 cm at 150% of ETc was 0.166 and 0.263 m³m⁻³ for the first and last stages of growth, respectively. 100% of ETc, (SM) was 0.296 m³m⁻³ at 0–25 cm, 0.195 m³m⁻³ at 25–45 cm, 0.179 m³m⁻³ at 45–62 cm, depths, respectively. whereas 50% of ETc, (SM) was 0.162 m³m⁻³ at 0–25 cm, 0.195 m³m⁻³ at 25–85 cm, depths. At 100% of ETc, soil salinity was 5.15, 4.37, 3.3, and 4.5 dSm⁻¹, whereas at 50%, ETc, these values were 5.64, 9.6, 3.3, and 4.2 dSm⁻¹. Statistical indicators showed that the model underestimated yield, for 150%, 100%, and 50% of ETc. Therefore, it can be concluded that yield and WUE using PRD systems were the highest in the potato crop compare to CDI surface and sub-surface, and SALTMED model can predict the moisture distribution, salinity, and yield of potatoes after accurate adjustment.

The scarcity of high-quality water in arid regions like Saudi Arabia necessitates saline water use in irrigation. Sustainable techniques, such as grafting and soilless cultivation, enhance crop resilience and optimize resource use, ensuring long-term agricultural and water sustainability to meet rising food demand. So, this study evaluated grafting’s effectiveness in enhancing the salt tolerance of tomato (Solanum lycopersicum L.) under soilless culture. The experiment tested two salinity levels, two growing media (volcanic rock and sand), and six grafting treatments: the scion ‘Tone Guitar F1’ was cultivated through non-grafting (G1), self-grafted onto itself (G2), and grafted onto the commercial rootstock ‘Maxifort F1’ (G3), which was grafted onto three newly developed rootstocks, namely X-218 (G4), X-238 (G5), and Alawamiya365 (G6). The results indicated that plants performed better at 2 dS m⁻¹, while higher salinity (4 dS m⁻¹) negatively impacted growth. However, grafting under saline stress improved most of the measured traits, excluding fruit quality (vitamin C, titratable acidity, and total soluble sugars). Grafted plants (G2–G6), particularly those grown in volcanic rock at 2 dS m⁻¹, exhibited superior fruit characteristics, yield, water productivity, and leaf calcium (Ca²⁺) and potassium (K⁺) content compared to the non-grafted controls (G1). The sand medium generally produced lower values for all the traits, regardless of salinity or grafting. Moreover, grafting under 2 and 4 dS m⁻¹ reduced leaf sodium (Na⁺) and chloride (Cl⁻). The best overall performance was provided by the rootstocks X-218 and X-238. Grafting onto salt-tolerant rootstocks is a promising strategy for improving tomato yield and water productivity under saline irrigation in arid and semi-arid regions.