Drought–Rewatering Dynamics in Chinese Cropping Systems: A Meta-Analysis of Yield Loss Mitigation, Water Use Efficiency, and Compensatory Physiological Response

Drought stress, being a crucial abiotic stress factor, and its recovery mechanism after rehydration are important in regulating crop production. This meta-analysis investigates the effects of drought stress followed by rewatering (DSRW) on crop productivity and water use efficiency (WUE) in Chinese cropping systems, synthesizing data from 90 studies (1997–2023) encompassing 2606 experimental observations. Results indicate that DSRW significantly reduced crop yield (CY) across plant types, with monocots (20.31% decline) outperforming dicots (23.64%) and woody plants (19.98% decline) showing greater resilience than herbaceous species (21.52%). WUE improved in woody plants (+7.81%) but declined in herbaceous crops (−9.44%), with notable increases in Chenopodiaceae (+59.39%) and Malvaceae (+11.35%). Mild drought stress (>65% field capacity) followed by short-term rewatering during early growth stages minimized CY losses (−19.60%) and WUE reduction (−6.89%), outperforming moderate or severe stress. Physiological analyses revealed DSRW-induced declines in photosynthetic parameters (e.g., net photosynthetic rate: −11.54%) but enhanced antioxidant enzyme activities (CAT: +18.21%, SOD: +10.23%) and osmoregulatory substance accumulation (proline: +16.22%). The study highlights the compensatory potential of strategic rewatering timing and intensity, advocating for early-stage, mild drought interventions to mitigate yield losses, which provide a practical value for promoting the sustainable development of water-saving agriculture. Future research should address regional climatic variability and crop quality responses to DSRW, advancing climate-resilient agricultural practices.