Faba bean is an important legume crop wordwide, grown both for food and feed. As for many legume crops, postemergence weed control is difficult. The aim of this work was to assess potential of intercropping on weed management by assessing the effect of mixing faba bean with different crops (wheat, barley, and pea) on weeds in the South of Spain. Four field trials were conducted over four consecutive seasons, and results found that addition alternate intercropping of faba bean and barley achieved high levels of weed control, both for coverage and biomass (92.7% and 76.6%, respectively). Intercropping with wheat did not reduce weed coverage but did decrease weed biomass by 46.1% as compared to faba bean monocrop. Intercropping with pea did not provide significant reductions for weed coverage neither for weed biomass. The diversity of the weed community was not altered by the different crop combinations tested. Additional experiments under controlled conditions were carried out to determine a possible role of barley allelopathy in weed suppression. A strong allelopathic effect entailing a reduction in the number of plants and biomass was detected for four weeds: Sinapis arvensis, Polypogon monspeliensis, Matricaria camomilla, and Medicago trucatula. It can be concluded that intercropping faba bean with barley is an excellent strategy for weed control in the Southern Spain.
