Nonwood Biochar Mitigates the Adverse Effects of Salt and Water Stress on Pea ( Pisum sativum L.) Growth, Yield, and Water Use Efficiency

Abiotic stress is a major constraint limiting plant growth, productivity, and agricultural sustainability worldwide. Biochar, a carbon‐rich material produced through biomass pyrolysis, has been proposed as an effective soil amendment to enhance plant resilience under stress conditions; however, limited information is available regarding its role in leguminous crops exposed to combined abiotic stresses. Therefore, a pot experiment was conducted to investigate the interactive effects of salt stress and water stress on pea ( Pisum sativum L.) growth, phenology, leaf gas‐exchange attributes, grain yield, and water use efficiency (WUE). Salt and water stress significantly disrupted pea phenology, particularly delaying flowering, and adversely affected leaf gas‐exchange parameters. Salt stress reduced transpiration rate, intercellular carbon dioxide (CO 2 ) concentration, stomatal conductance, and net photosynthetic rate by 27%, 11%, 27%, and 21%, respectively. In contrast, biochar incorporation significantly increased pea grain yield by 3–15%. Water stress and biochar application enhanced yield‐based water use efficiency (WUE‐yield) by 28% and 16%, respectively, whereas salt stress reduced WUE‐yield by 24%. These findings demonstrate that salt and water stress substantially limit pea productivity, while biochar application can partially mitigate their negative impacts. Evaluating the interactive effects of multiple abiotic stressors is essential for developing sustainable crop management strategies.