Planning for Drought
On Colorado Rangelands
Colorado ranchers and rangeland
managers can expect drought at
least once every five years and
should develop a drought plan
Effects of Drought on Plant
Growth Depend on
• Severity and duration of the drought
• Health of vegetation going into it.
– Plants in low vigor suffer more or die
– Plants in good condition produce less
– Period of growth and forage quality are
reduced
Effects of Drought on Plant
Growth
• Plants may go dormant before the end of
the normal growing season.
• Drought increases the rate of natural dieoff of plant roots.
• Reduces vigor and forage production
Early Dormancy
• Cause plants to enter a longer than normal
dormant period
• Plants become dependant on root reserves
earlier in the year
• Deplete root reserves needed for next
springs growth
• Reduce vigor on next years plants
Increased Root Die-Off Rates
• Reduce ability to obtain nutrients and
water from soil
• Reduce plant vigor and forage production
• Lengthen recovery periods
Effects of Drought on Animal
Performance
• If stocking rates are adjusted to carrying capacity
animal performance may be maintained
• If forage production does not meet animal
requirements weaning weights may be reduced
by 50-100 lbs.
• Can cause delays in cows cycling (especially in
first calf heifers)
Other Effects of Drought
• Fewer water sources
• Poor quality water sources decrease forage
intake and performance
• Livestock distribution problems
Managing during and after
drought
• Drought stricken ranges should be
managed to promote root replacement and
increasing plant vigor
– Deferment from early spring grazing is
important for reestablishment of vigorous root
systems
– Because forage production is less, ranges
cannot be stocked at the same levels as in
normal years. Reduction in grazing pressure is
necessary to allow for recovery in a short time.
Management Options
• Reductions in grazing pressure are necessary to
allow for short term recovery
• Haul water
• Move livestock more often
• Grazing systems that provide for root reserves or
rest during normal years provide flexibility
during times of drought
• Provide for longer periods of rest /recovery
• Increase number of pastures
• Use other feed sources (crop aftermath and byproducts)
Animal Management
• Wean and sell calves earlier
• Cull low performance cow/open cows
early
• Reduce number of replacements
What can be done on BLM and
Forest Service Allotments
• Use non-use for resource protection
• Use more remote or less frequently used portions of the
range
• Use less reliable sources of water first
• Design grazing systems that respond to drought conditions
• Consider each situation on a case by case basis.
• Keep healthy root systems and increased plant vigor as
your goals during drought and normal years.