Non-Peer ReviewedUnderstanding the effect of long-term grazing on alfalfa populations is important for identifying superior alfalfa genotypes adapted to animal grazing. The objective of this study was to compare alfalfa populations collected from 14 ranch sites across four soil zones of Saskatchewan for dry matter at first and second cuts, stem number) plant height forage nutritive value (protein, fibers), and verticillium wilt resistance. Crude protein concentration was significantly different (P<0.001) among the populations, but fiber concentrations (acid detergent and neutral detergent fiber) were similar. Resistance (%) to verticillium wilt varied (P=0.0028) among the alfalfa populations. The initial results indicated that DM at first cut was significantly different (P<0.0001) among 14 alfalfa populations, with alfalfa population from MacDowell had the highest first cut DM (287.8g) and regrowth DM (121.7g). Among the four soil zones, alfalfa populations from Black Soil Zone had the highest DM (P<0.0001) at first cut than alfalfa populations from Brown, Dark Brown and Grey wooded soil zones. During regrowth, alfalfa populations from Black (99.7g) and Grey wooded soil zones (99g) had significantly (P<0.001) higher DM than those from Dark Brown (82.6g) and Brown (81.9g) zones. Also, plant height (PH) among 14 alfalfa populations was significantly different (P<0.0001), with plants in MacDowell being tallest (90.4 cm), and in Val Marie population being the shortest (67.3 cm). Furthermore, stem number at first cut was significantly different (P<0.0163), with MacDowell had the highest stem number (98 stem plant-1), and Val Marie had the lowest (68 stem plant-1). There were positive correlations between DM yield with plant height at first cut (R=0.68, P<0.0001) regrowth DM with stem number (R=0.76, P<0.0001). In conclusion, alfalfa populations from these long-term grazing sites had diverse for the measured traits in this study, which may be useful for further selection for grazing tolerance and regional adaptation
