Stale Seedbed and Intercropping for Agroecological Weed Management in Vetch (Vicia sativa L.) in the Context of the ONE GREEN Project

Agroecological weed management is important for agriculture’s shift toward sustainability. This study evaluated stale seedbed and intercropping combinations for weed management in vetch (Vicia sativa L.) cultivation in Greece during the 2023–2024 and 2024–2025 growing seasons. A Randomized Complete Block Design was established using a split-plot arrangement. Two weed management practices served as the main plots: untreated control (CON) and stale seedbed (SSB). Four intercropping methods formed the subplots: vetch monocropping (VM), vetch–barley mixed intercropping (VBMXIC), vetch–barley row intercropping (VBROWIC), and vetch–barley relay intercropping (VBRELIC). The interaction between weed management and intercropping influenced weed NDVI (p < 0.001), weed biomass, and vetch NDVI (p < 0.01). Weed NDVI and biomass were highest for CON × VM, CON × VBMXIC, CON × VBROWIC, and CON × VBRELIC interactions. Vetch NDVI was highest (0.71) for SSB × VM. Grain yield was affected by growing season (p < 0.05), weed management (p < 0.001), and intercropping (p < 0.001). SSB resulted in a 42% higher yield compared to CON. VBRELIC and increased yields by 7%, 22%, and 29% compared to VBROWIC, VM, and VBMXIC, respectively. Further research is needed to evaluate additional agroecological weed management practices in more crops and environments.