Physiological mechanisms and agronomic strategies underlying flood tolerance variability in dryland crops: A global meta-analysis

Abstract

Context

The increasing frequency of flooding events poses significant challenges to global agricultural sustainability in dryland systems, demanding urgent insights into crop-specific resilience mechanisms and adaptive strategies linked to yield formation.

Methods

Through a global meta-analysis of 217 peer-reviewed studies, we systematically evaluate flood tolerance and agronomic mitigation strategies across six major dryland crops (cotton, maize, peanut, rapeseed, soybean, and wheat) by integrating yield, biomass, and physiological traits (e.g., photosynthesis, antioxidant enzymes). A novel flood tolerance index (FTI) was developed to quantify resilience.

Results

Among the six crops examined, wheat and rapeseed demonstrated the highest flood tolerance (FTI: 0.80 and 0.77, respectively), followed by soybean and cotton (0.68 and 0.64), while peanut and maize displayed the lowest tolerance (0.61 and 0.57). These variations in flooding tolerance align with differences in reliance on three adaptation strategies: quiescence (e.g., antioxidant enzyme activity), compensatory growth (post-flood photosynthetic recovery), and escape (aerenchyma formation), regulated by flood-responsive genes such as Zea mays ethylene response factor B 180 (ZmEREB180) and Brassica napus phytoglobin 1 (BnPgb1). Agronomic interventions, such as raised-bed cultivation, bio-stimulants, post-flood fertilization and diversified intercropping, enhanced crop yield by 7.3–55.2 % through improving these adaptation strategies.

Conclusions

The analysis reveals significant variation in flood tolerance among dryland crops, driven by different reliance on escape, quiescence, and compensatory strategies. Building on these insights, we propose a flooding-smart adaptation (FSA) framework that integrates crop physiology with agronomic practices, offering a scalable pathway to mitigate economic losses and stabilize productivity in flood-prone regions. This study advances methodologies for resilience assessment and provides actionable strategies to align crop ecology with climate-smart agriculture.