Managing Horse Pasture During and After a Drought

Dormancy

If you are in a drought and your pastures are composed of cool-season grasses like orchardgrass, tall fescue, Kentucky bluegrass, etc., they may be dormant and brown right now. Don't worry - they're probably not dead! Dormancy allows plants to adapt to drought stress. The leaves may stop growing or even die, but the growing point and energy storage area at the base of the plant (the crown) is still alive. If your pasture grasses are well-established and have deep root systems, they will revive with some moisture and cooler weather. A new seeding, however, may not have the energy reserves to survive the drought.

If possible, it is best not to graze pastures during a drought or while they are dormant. The grass cannot recover from the leaf removal and regrow during drought and dormancy. Without leaves, the grass plant cannot capture enough sunlight for photosynthesis and regrowth. If the crown is grazed, precious energy stores needed for recovery are removed.  Additionally, a thin stand of grass exposes bare ground, allowing opportunistic weed seeds to germinate and spread later in the year.

Horse Nutrition and Health

While this may seem counterintuitive, drought can cause cool-season pasture grasses to accumulate non-structural carbohydrates (NSC) like sugars and fructans. Before the leaves die, they continue to produce NSC via photosynthesis, however the plant cannot use up those NSC for growth without water. Therefore, the NSC accumulate until growth can resume.