Irrigation management for sustainable intensification of faba bean production: Synergizing yield, soil health, and water use efficiency

Efficient water–fertilizer management is essential for enhancing the productivity and sustainability of faba bean ( Vicia faba L. ), particularly in systems where conventional practices rely on excessive inputs and contribute to resource waste and non-point source pollution. This study compared three irrigation amounts (190, 163, and 136 mm) and two irrigation frequencies (12 and 24 events) under drip fertigation, alongside conventional surface irrigation (CK), to identify an optimized water-management strategy that improves yield, water use efficiency, and partial factor productivity of fertilizer (PFP). Drip fertigation markedly increased yield and PFP by optimizing root-zone water supply, enhancing nutrient availability, and promoting dry-matter accumulation. The DH (high-frequency and high-amount drip irrigation) treatment achieved the greatest improvements, with 80.8 %–85.4 % higher yield and 143.6 %–161.9 % greater PFP than CK. Yield was primarily driven by stem dry weight, stem diameter, and 100-grain weight, while PFP was influenced by stem traits and branch number. Among all treatments, the low irrigation amount combined with high irrigation frequency (136 mm, 24 irrigations) provided the most effective water strategy, delivering the highest integrated performance in productivity and resource efficiency. This optimized water strategy is recommended for regions experiencing seasonal water scarcity, offering a practical pathway to enhance yield while reducing resource inputs and environmental impacts. Future research should assess the long-term stability and broader applicability of this water strategy across different soil conditions, climates, and legume production systems.