Sudangrass can be used as a companion crop to establish alfalfa

Small-grain cereals such as oat are traditionally used as companion crops to establish alfalfa in Quebec. The use of annual companion crops is motivated by the fact that they often suppress weeds and increase harvestable forage. The use of other recently introduced annual species such as sudangrass has not yet been evaluated.

In an article soon to be published in Crop, Forage & Turfgrass Management, researchers report on a study conducted in southwestern Quebec comparing the use of sudangrass as companion crop for alfalfa establishment to that of oat and annual ryegrass.

Researchers found that when seeded in June, sudangrass used as a companion crop may increase forage yields in the seeding year when compared with oat (forage) and ryegrass. Moreover, sudangrass was found to be less competitive with alfalfa than oat or annual ryegrass, resulting in higher alfalfa yields in the seeding year. Sudangrass also has limited impact on alfalfa stand density and yields in the post-seeding year.

This study suggests that sudangrass may be a potential alternative to traditional species such as oat to establish alfalfa fields in southwest Quebec. However, evaluations in more environments are required to determine if this approach could be applied to other regions of Quebec.