Dh. Mccartney et S. Bittman, PERSISTENCE OF COOL-SEASON GRASSES UNDER GRAZING USING THE MOB-GRAZING TECHNIQUE, Canadian Journal of Plant Science, 74(4), 1994, pp. 723-728
Evaluation of grass germplasms for pasture is usually done in trials w
hich are harvested mechanically. This study evaluated the persistence
of 13 cool-season grass species and germplasms under 4 yr of grazing i
n northeast Saskatchewan, using the mob-grazing technique. Thirteen gr
ass germplasms were contained within each paddock, and the paddocks we
re grazed by large groups of cattle so that all the herbage was consum
ed evenly in 1-2 d. Three grazing intensities (light, moderate and int
ense) were established by varying the rest period between gratings. Gr
ound cover declined more rapidly under intense than under light grazin
g, but no interaction was found between grazing intensity and grass ge
rmplasm. The ground cover of the seeded grasses generally declined but
at different rates during the trial, giving a significant grass x yea
r interaction. Parkway crested wheatgrass [Agropyron cristatum (L.) Be
auv. ssp. pectinatum (Bieb.) Tzvel.] declined less than Carlton smooth
bromegrass (Bromus inermis Leyss.) and the meadow bromegrass (Bromus
biebersteinii Roem and Schult.) cultivars. The most rapid stand declin
e was observed in intermediate wheatgrass [Elytrigia intermedia (Host)
Nevski], northern wheatgrass (Elymus lanceolatus Scribn. gr Smith), a
nd hybrid wheatgrass [Elytrigia repens (L.) Nevski x E. spicata (Pursh
) D. R. Dewey]. Seeded grasses were replaced mainly by bluegrass (Pea
spp.). The results suggest that mob grazing is a useful technique for
evaluating new species and germplasms intended for long-term pastures.