Grain yield and N benefits to sequential wheat and barley crops from single-year alfalfa, berseem and red clover, chickling vetch and lentil. Can. J. Plant Sci. 82: 53-65. Singleyear hay alfalfas (Medicago sativa L.), berseem (Trifolium alexandrinum L.) and red clovers (Trifolium pratense L.), chickling vetch (Lathyrus sativus L.) and lentil (Lens culinaris Medik.) were evaluated for rotational yield and N benefits to the following first-year wheat (Triticum aestivum L.) and second-year barley (Hordeum vulgare L.) crops. Field experiments were initiated in 1997 and 1998 on a Riverdale silty clay soil at Winnipeg, Manitoba. Yield and N content of the following wheat crop were increased following legumes compared to wheat following a canola control. Wheat yield and N content averaged 2955 kg ha -1 and 76.1 kg ha -1 , respectively, following the chickling vetch and lentil, 2456 kg ha -1 and 56.4 kg ha -1 following single-year hay legumes, compared with 1706 kg ha -1 and 37.9 kg ha -1 following canola. Non-dormant alfalfas (dormancy rating of eight or greater) contributed to larger grain yields than the dormant alfalfas only in the first year of each experiment. The chickling vetch and lentil provided similar or higher subsequent crop yields and N content for 2 yr compared to a canola control or fallow treatment. This study shows that some increase in yield can be achieved by using a single-year alfalfa hay crop instead of fallow; however, exclusive green manuring of chickling vetch and lentil crops can produce the most increase in yield and N uptake in subsequent crops. par hectare, respectivement, après la culture annuelle de légumineuses, comparativement à 1 706 kg et à 37,9 kg par hectare, respectivement, après la culture de canola. La luzerne non dormante (facteur de dormance au moins égal à huit) a concouru à un meilleur rendement grainier que la luzerne dormante, mais la première année seulement dans chaque cas. La culture de gesette et de lentille entraîne un rendement et une concentration d'azote analogues ou supérieurs à ceux obtenus avec le canola ou la jachère, les deux années suivantes. L'étude indique qu'on peut parvenir à une certaine hausse de rendement après une culture annuelle de luzerne au lieu de jachère, mais la plus grande amélioration de rendement et de la concentration d'azote survient quand on utilise la gesette et la lentille comme engrais verts.