HomeMy WebLinkAboutThe Rural Voice, 2000-09, Page 65Tips on summer
seeding alfalfa
By Joel Bagg, Forage Specialist,
OMAFRA, Lindsay
The most reliable time to seed
alfalfa is in the spring. With an April
or early May seeding, moisture is
usually adequate and the plants are
well established for winter survival.
However, spring seeding is not
always possible due to a number of
factors, including the wet field
conditions we have experienced this
year.
Summer seeding of alfalfa forage
mixtures can be a viable alternative
to spring seeding. Fields seeded this
summer can be treated as established
stands next year with full yield
potential. Companion crops are not
needed or recommended because
they compete too strongly for
available soil moisture. Summer
seedings can work well on lighter
soils, but present a higher risk on
heavier soils.
The following are some points to
consider regarding successful
summer seeding of alfalfa:
• Seeding Date — There are two
critical risks associated with summer
seeding alfalfa. Seeding alfalfa too
early in the summer increases the risk
of hot, dry conditions during
germination and seedling
development. Summer seedings
usually fail when seeds germinate
and then starve for moisture.
Seeding too late increases the
chance of freeze-up before the alfalfa
seedlings are adequately established.
Seeding must be done early enough
so that the alfalfa can accumulate
enough root reserves to survive the
winter. Alfalfa needs about six weeks
growth after germination to survive
the winter, and will generally survive
if a crown develops before a killing
frost. In the 2500 to 2900 CHU areas,
optimum summer seeding dates
would be from August 1 - 10. In
areas greater than 2900 CHU, August
10 - 20 would be optimum. Trefoil
has slow seedling development; so
summer seedings of trefoil are
usually unsuccessful.
• Fertility and pH — Rapid growth
Advice
and establishment of alfalfa seedlings
is important. Apply the required
fertilizer and lime according to a soil
test. If soil phosphorus levels are
low, applying a starter phosphate
fertilizer two inches below the seed
in a band will encourage rapid. root
growth and establishment. For soils
low in pH, lime should be added at
least a year in advance to allow for
reaction in the soil.
Seedaed Preparation — Seed to soil
problem, especially if a lot of Tight
grain went through the combine.
Tillage can reduce the problem. If
there is enough moisture, a light
cultivation will prompt the grain to
germinate so that it can be destroyed
by another cultivation. Plowing to
bury the grain also works well, if
feasible. In pure alfalfa stands, a
grass herbicide can be used.
• Use Recommended Varieties —
High performance. disease resistant.
SEPTEMBER 2000 61