The use of saline water under drought conditions is critical for sustainable agricultural development in arid regions. Biochar is used as a soil amendment to enhance soil properties such as water-holding capacity and the source of nutrition elements of plants. Therefore, the experiment was conducted to evaluate the effects of biochar application on the morpho-physiological traits and yield of tomatoes under combined salinity and drought stress in greenhouses. There were 16 treatments consist two water quality fresh and saline (0.9 and 2.3 dS m⁻¹), three deficit irrigation levels (DI) 80, 60, and 40% addition 100% of Evapotranspiration (ETc), and biochar application by rate 5% (BC_5%) (w/w) and untreated soil (BC_0%). The results indicated that the salinity and water deficit negatively affected morphological, physiological, and yield traits. In contrast, the application of biochar improved all traits. The interaction between biochar and saline water leads to decreased vegetative growth indices, leaf gas exchange, the relative water content of leaves (LRWC), photosynthetic pigments, and yield, especially with the water supply deficit (60 and 40% ETc), where the yield decreased by 42.48% under the highest water deficit at 40% ETc compared to the control. The addition of biochar with freshwater led to a significantly increased vegetative growth, physiological traits, yield, water use efficiency (WUE), and less proline content under all various water treatments compared to untreated soil. In general, biochar combined with DI and freshwater could improve morpho-physiological attributes, sustain the growth of tomato plants, and increase productivity in arid and semi-arid regions.

The use of saline water under drought conditions is critical for sustainable agricultural development in arid regions. Biochar used as a soil amendment to enhance soil properties such as water-holding capacity and the source of nutrition elements of plants. Therefore, the experiment was conducted to evaluate the effects of biochar application on the morpho-physiological traits and yield of tomatoes under combined salinity and drought stress into greenhouses. There were 16 treatments consist two water quality fresh and saline (0.9 and 2.3 dS m-1), three deficit irrigation levels (DI) 80, 60, and 40% addition 100% of ETc, and biochar application by rate 5% (BC5%) (w/w) and untreated soil (BC0%). The results indicated that the salinity and water deficit negatively affected morphological, physiological, and yield traits. In contrast, the application of biochar improved all traits. The interaction between biochar and saline water leads to decreased vegetative growth indices, leaf gas exchange, relative water content of leaves (LRWC), photosynthetic pigments, and yield, especially with the water supply deficit (60 and 40% ETc), where the yield decreased by 42.48% under the highest water deficit at 40% ETc compared to the control. The addition of biochar with freshwater led to significantly increased of vegetative growth, physiological, yield, WUE, and less proline content under all various water treatments compared to untreated soil. In general, biochar combined with DI and freshwater could be improve morpho-physiological attributes, to sustain the growth of tomato plants, and increase productivity in arid and semi-arid regions.

Grafting high-yielding tomato varieties onto stress-tolerant rootstocks can mitigate the adverse effects of saline water irrigation on plant tomato productivity in arid regions like Saudi Arabia. This study investigates the efficacy of grafting tomatoes onto both novel and commercial rootstocks to enhance salinity tolerance and its impact on growth, physiological parameters, and yield in a soilless culture system. The experiment involved two water quality levels, 2 (S1) and 4 (S2) dS m⁻¹, two growth media types, volcanic rock (M1) and sand (M2), and six grafting treatments: Tone Guitar F1 non-grafted (G1) (commercial scion), grafted onto itself (G2), Tone Guitar F1* Maxifort F1 (G3) (commercial rootstock), and grafting the scion onto three novel rootstocks, X-218 (G4), X-238 (G5), and Alawamiya365 (G6). Growth, physiology, photosynthetic pigments, and yield improved with lower salinity (2 dS m⁻¹) in volcanic rock and with the grafting treatments (G2–G6) compared to the non-grafted treatment (G1). The best results were achieved with the S1M1G5 treatment, where yield increased by 53% compared to the lowest yield in non-grafted plants grown in sand under higher salinity (S2M2G1). All studied traits were adversely affected under high salinity (S2) in sandy media, with the G1 treatment resulting in the lowest values for these traits.

Enhancing the utilization of water in desert areas, including Saudi Arabia, has become essential for achieving agricultural sustainability. Biochar effectively mitigates ecological stresses through retaining water, altering soil properties, and providing nutrients for plant growth. This study aimed to examine the impacts of biochar addition on morpho-physiological characteristics, yield, and water productivity (WP) in greenhouses under drought stress conditions. The experiment combined three levels of deficit irrigation (DI)—40, 60, and 80% ETc—as well as two rates of biochar (BC)—BC3% and BC5% w/w (1.28 and 2.13 kg m⁻², respectively, for planted area); the control was 100% ETc and untreated soil (BC0%). The results indicated that water deficit hurt the plants’ morpho-physiological characteristics and crop yield. For instance, irrigation water shortage decreased yield by 30.88% at 40% ETc compared to the control (100% ETc). However, DI improved WP by 72.80% at 40% ETc compared to the control. The interaction between DI and BC positively affected morphological, physiological, yield, and WP. For instance, the highest rate of biochar (BC5%) increased yield by 11.92% at 80% ETc compared to untreated plants (BC0%). Similarly, tomato plants treated with 5% biochar under the lowest irrigation level of 40% ETc achieved the highest increase in WP (79.33%) compared to the control (100% ETc and BC0%). In general, DI combined with BC could improve morpho-physiological attributes and yield while increasing the WP of tomato plants in arid and semi-arid regions.