Ability of Sainfoin and Cicer Milkvetch Populations to Rejuvenate Existing Pastures in Western Canada.

New sainfoin populations developed for mixed cropping with alfalfa can produce high biomass and prevent bloat in grazing cattle. However, ability of new sainfoin populations to rejuvenate old alfalfa or grass pastures has not been tested. A multiyear and multi-location study was initiated to determine if new sainfoins known for their ability to survive in mixed stands with alfalfa can be used to rejuvenate depleted alfalfa and grass pastures. New cicer milkvetch (CMV) cultivars were also tested along with different types of drills for adequate pasture rejuvenation. In this study, sainfoin and CMV performed better in alfalfa pasture than grass pastures. Between the two legumes, sainfoin established and contributed more than CMV in both legume and grass pastures during the three study years. Among sainfoin cultivars, old sainfoin cultivar Nova and two new populations Mountainview and LRC3432 contributed >20% in alfalfa pasture at Lethbridge and >10% in grass pasture at Red Deer. As a result grass-legume mixtures showed increased protein content and improved relative feed value. At Ponoka, however, all tested populations of sainfoin and CMV contributed less than 3% to total DM yield of pasture mixture. It can therefore be concluded that some of the sainfoin populations tested may be directly drilled into old pastures for rapid rejuvenation in parts of western Canada. One noticeable observation in this study was that alfalfa cultivar AC Blue J demonstrated the ability to establish in freshly broken alfalfa pasture contrary to old recommended practice of allowing an extended rest period before replanting alfalfa.