Diversifying crop rotations with perennial forage crops: potential benefits for weed management & farmland biodiversity

Crop rotation may be used to prevent the continuous selection of weed species adapted to one crop type. However, today’s crop rotations are often very short and simple. We studied the impacts of introducing perennial forage crops into cereal-based crop rotations on weed vegetation. Large-scale weed surveys in 632 fields in western France suggested that the weed species composition varied most strongly between perennial alfalfa forage crops and six annual crops[1]. Comparisons of wheat fields before, during, and after perennial alfalfa suggested that weed communities vary in a cyclic way during such crop rotations. This may be beneficial for weed management (suppression of weed species probl…