Interspecific Competitive Relationships Between Crop Components and Weeds in Mixed Cropped Faba Bean (Vicia faba L.) With False Flax (Camelina sativa Crantz)

Mixed cropping of Vicia faba with Camelina sativa enhances weed suppression and resource use efficiency, offering a sustainable alternative to chemical weed control. Early canopy closure by C. sativa—driven by rapid seedling establishment—created a functional living mulch that reduced bare soil exposure and suppressed weed seedlings by 78% compared to non-weeded controls, primarily through niche disruption. Although overyielding was moderate, the system maintained the absolute amount of nitrogen fixed symbiotically by V. faba, with no significant difference between sole and mixed cropping systems. However, V. faba performance was critically dependent on early soil nitrogen availability, which could not be fully compensated for by fixed nitrogen. To optimize yield stability, pairing short-strawed C. sativa with tall, high-yielding V. faba genotypes is recommended. This study demonstrates that C. sativa improves system resilience through weed suppression and efficient resource use, but its effectiveness hinges on strategic cultivar matching to balance competition and complementarity in mixed cropping systems.