Impact of Dry Weather on
Forages and Pastures
Producing enough stored forage to feed livestock can be a challenge
in dry years. Dry weather during the pasture "summer slump"
can quickly force people to prematurely use up their stored forage
supplies. Management strategies can help ensure adequate feed going
into the winter. These include good alfalfa management, potato leafhopper
control, rotational grazing, supplementing pastures with hay, restricting
livestock to a sacrifice paddock with full feed, and the use of
corn silage and other annuals. The Forage
Rainfall Insurance Program is available from Agricorp with an
enrolment deadline of May 1.
In Ontario, first-cut yields are largely a function of temperature,
whereas second and third-cut yields are more limited by available
moisture. One-half to two-thirds of total yield is typically from
- If there is adequate alfalfa growth to economically justify
cutting, and a 30 to 40 day harvest interval can be maintained,
cutting is recommended.
- Where the crop has reached the flower stage without adequate
volume for harvest, there won't be a lot of additional growth
even if the field receives rain. In these cases, clipping the
top growth will encourage growth of new crown buds, resulting
in an increase in forage yield.
- Potato leafhopper (PLH) damage on alfalfa is greatly underestimated.
PLH feeding affects the transportation of fluids and nutrients
in the plant and significantly worsens the effects of dry weather.
New seedings are very susceptible. PLH can be managed by scouting
and spraying at threshold levels, and by the use of PLH resistant
- Vigorous forage stands with good plant health resulting from
good fertility, variety selection (disease resistance, persistence),
drainage and weed control usually have better dry weather tolerance.
Healthy plants with a good root system are better able to withstand
dry conditions. Stands with chronic root and crown rots are often
not able to withstand extended dry periods.
- Stands with an early first-cut harvest date generally have more
summer regrowth, and may enable a successful third-cut harvest.
- Pastures that are over-grazed will take much longer to recover
from extended dry conditions. Managing pastures to maintain a
7 to 10 cm (3 to 4 inch) residual will aid in plant recovery and
help to retain any soil moisture.
- If feed is in short supply consider using non-traditional sources
of pasture, such as summer-planted annuals, and grazing hay fields
to extend the pasture.
For more information on dry conditions and low water go to our
website at ontario.ca/crops
and click on the Adverse Weather button.