Forage Yield, Quality, and Weed Suppression in Narbon Vetch (<i>Vicia narbonensis</i> L.) and Italian Ryegrass (<i>Lolium multiflorum</i> L.) Mixtures Under Organic Management

This study aimed to evaluate the forage yield, quality, and weed suppression potential of Narbon vetch (Vicia narbonensis L.) and Italian ryegrass (Lolium multiflorum L.) grown as sole crops and in mixtures under organic farming conditions in Bilecik, Turkey, during the 2020–2021 growing season. The experiment included 15 treatments comprising monocultures and mixed sowing at different ratios. Measurements included morphological traits, forage yield components (green herbage, hay, and crude protein), fiber content, botanical composition, and weed biomass. Results revealed significant differences among treatments in terms of growth parameters and forage performance. Monocultures of IFVN 567 and Bartigra showed the highest green and hay yields. At the same time, mixtures such as IFVN 567+Trinova and IFVN 567+Bartigra outperformed in terms of land equivalent ratio (LER) and protein yield, demonstrating a clear advantage in land use efficiency. Furthermore, these mixtures showed superior weed suppression compared to monocultures. Overall, the findings suggest that carefully selected vetch–ryegrass combinations can enhance forage productivity, nutritional quality, and weed management under organic systems.