Effects of drought and water salinity on crop nutritional quality and global food security

Drought and water salinity are among the most severe environmental stressors associated with climate change, affecting food production systems and global food security. The aim of this study was to quantitatively synthesize available scientific evidence on the effects of drought and water salinity on the nutritional composition of food crops and to identify key moderators influencing these relationships. A systematic literature review and meta-analysis were conducted using observational and experimental studies that assessed the impacts of drought and salinity on nutrient composition of food crops and nutritional indicators. Random-effects models were applied to estimate pooled effect sizes, and heterogeneity was assessed using the Q statistic and τ² estimator. Moderator analyses were performed to examine the influence of geographic region, crop type, and salinity level. Potential publication bias was evaluated using scatter plots. The meta-analysis revealed a significant negative effect of both drought and salinity on crop nutritional outcomes, with drought showing a stronger and more consistent pooled effect than salinity. For salinity, effect sizes increased with salinity intensity, suggesting the presence of critical thresholds beyond which nutritional quality declines markedly. Moderator analyses indicated substantial regional differences and crop-specific responses, highlighting the context-dependent nature of these environmental stressors. These findings demonstrate that drought and water salinity represent important risk factors for food quality and crop nutritional quality, whose impacts are likely to intensify under future climate change scenarios. The study underscores the need to integrate agronomic and nutritional perspectives when assessing climate-related stressors and to develop targeted adaptation strategies aimed at safeguarding food security and nutritional quality.