Evaluation of Low Heat Unit Corn Hybrids Compared to Barley for Forage Yield and Quality on the Canadian Prairies

Corn (Zea mays L.) production is expanding in the prairie region of western Canada. The objectives of this study were to compare three new low heat unit corn hybrids to barley (Hordeum vulgare L.) for forage yield, nutrient profile, and total nutrient production. The study was conducted at 4 sites (Evansburg and Fairview, Alberta; Melfort and Scott, Saskatchewan) with different soil characteristics (Gray Luvisolic, Grey Wooded, Dark Brown, and Black soil zones) over three consecutive years (2012-2014). At each site, annually, 16 plots (2.4×7.2 m) were randomly assigned to one of four forage crops (corn:Monsanto DKC26-25, Hyland 2D093, Pioneer P7443R; barley: cv. AC Ranger) in a replicated (n = 4) trial. Number of cobs per plant was not different (p = 0.23) between corn hybrids averaging 1.22 ± 0.32/plant (mean ± sd). Forage yield among the corn hybrids was negligible (p > 0.05), but the corn hybrids exhibited 40% higher yield (p < 0.05; avg. 11.3 ± 3.6 t/ha on DM basis) compared to barley (avg. 6.7 ± 1.7 t/ha). Corn hybrids were lower (p < 0.05) in CP content [7.6 ± 1.4% versus (vs.) 12.4 ± 0.1%] than barley. No difference was observed between the 4 forage crops in TDN content (68.2 ± 2.8% DM).Study results suggestthat new cool-season corn hybrids can produce high quality forage to meet the nutrient requirements of grazing beef cows in mid- and late-stage pregnancy.New corn hybrids may be suitable alternatives for winter grazing strategies since forage harvest costs would be eliminated.