Quantitative relationships between salty water irrigation and tomato yield, quality, and irrigation water use efficiency: A meta-analysis

The scarcity of freshwater resources has suppressed the sustainable development of agriculture, especially to-mato production. Adopting salty water irrigation is considered a promising strategy for alleviating the scarcity of freshwater resources. However, the effects of salty water electrical conductivity (EC) and cultivation conditions on tomato yield, irrigation water use efficiency (IWUE), and fruit quality remain unclear. In this study, we conducted a meta-analysis based on 1230 data pairs from 56 research papers reporting these aspects of tomato production. Overall, salty water irrigation significantly decreased tomato yield (-26.15%) and IWUE (-24.65%) and increased total soluble solids (13.68%), organic acids (13.78%), sugar and acid ratio (8.04%), and vitamin C (9.78%) compared to freshwater irrigation. Reduction in tomato yield and IWUE increased with salty water EC. Brackish (EC < 3 dS m-1) and moderately saline water (3 < EC < 8 dS m-1) were recommended considering their greater potential to maintain both yield and quality. Though soil bulk density had no significant effect on tomato yield, the soil with high bulk density was beneficial for improving tomato quality. Increasing soil organic matter reduces the negative effects of salty water irrigation. A win-win analysis showed that brackish and moderately saline water were suitable for drip irrigation and alkaline soils. These results will be beneficial to maintain high yields and fruit quality in tomato production using salty water irrigation.