The Aspen Parkland of western Canada constitutes a major portion of th
e agricultural areas of Manitoba, Saskatchewan and Alberta, with 86 %
of the forage production and 66% of the beef cattle herd. Although som
e areas still exist in the natural state, most of the Parkland has bee
n cleared of aspen (Populus tremuloides Michx.) for farming. Introduce
d pasture species have been seeded, and bromegrass (Bromus inermis L.)
and alfalfa (Medicago spp.) have been found to be the most productive
. The addition of nitrogen and phosphorus fertilizer has been shown to
nearly triple forage production in the presence of adequate moisture
and favorable temperatures. Straight nitrogen has resulted in a reduct
ion of the proportion of alfalfa in a mixed sward. The severity and ti
me of grazing have a marked effect on pasture productivity. Bush pastu
res can be renovated by using selective herbicides, fire and controlle
d grazing to manage woody brush regrowth or by sod seeding of alfalfa
in the depleted stands. Spring-seeded winter cereals can be grazed thr
oughout the growing season or as part of a grazing rotation with peren
nial forages by extending the grazing season in the fall.