Managing Pasture During Drought Conditions
A prolonged dry spell can be a horse or cattle owner's worst nightmare. Besides limiting a pasture's forage output, drought makes pasture plants more sensitive to the effects of overgrazing and trampling from hooves. Lack of rain can also lead to an increase in weeds—some of which may be toxic to animals—that compete with desired grasses.
Although they can't control the weather, pasture owners can reduce a drought's impact on their land. The basic principles of good pasture management also apply in drought conditions, and, in fact, the importance of these principles only increases during dry weather.
Preserve the roots
Pasture plants' root systems are key to helping the pasture survive stress from drought and grazing and are essential for erosion control and soil stability. Root growth depends on photosynthesis; if your pasture grasses are clipped too heavily by grazing animals, it's going to take longer for the pasture to recover from dry weather. Avoid overgrazing and, when the rains do return, resist the temptation to graze drought-impacted plants until they've fully recovered. Even when plants green up after rains, the pasture needs some time for the roots to recover. Graze too soon, and you'll prolong the recovery period or even make recovery impossible.
University of West Virginia Extension specialists recommend that pasture owners keep an eye on the fertility levels of pasture soils in the late summer, even during periods of dry weather and limited plant growth. When the rains return, a pasture that already has the correct amount of nutrient levels in its soils will respond better to the moisture. If you consider dry weather fertilization, be sure to use a nitrogen source that won't break down and evaporate in the absence of rain. Urea fertilizers, for example, will break down in dry weather if moisture doesn't carry the fertilizer into the soil within a few days. Note that pastures may benefit from late-summer fertilizer applications even if the rains don't return until October. Added nutrients will help the plants grow roots and tillers, which should better prepare the pasture for winter and increased production of forage in the spring.
Use caution, however. According to the NRCS's National Range and Pasture Handbook, nitrogen over fertilization on summer annual grass pastures during a drought can contribute to nitrate or prussic acid poisoning. Tests are available to detect these poisons.
A drought may require you to be flexible in your rotational grazing plans. A paddock of adequate size for the animals in times of plentiful water may be too small during a drought because it doesn't produce enough forage. In a rotational grazing plan, you may need to skip pastures where the soil doesn’t hold moisture well; those areas will require additional time to recover.
Managing cattle pastures
Forage production levels may be reduced during a drought; it's important to manage grazing carefully in order to get the most out of your pasture—but be sure not to over graze. Rest the pasture through rotational grazing and avoid grazing grasses too short. As a rule of thumb, West Virginia extension specialists suggest keeping animals off the pasture unless bluegrass has reached four to six inches, and orchard grass and tall fescue has grown eight to 10 inches.
If the plants don't receive enough rain to reach these heights, wait until October—or whenever the grass would normally stop growing due to cool weather—and graze to a four-inch stubble for grasses or a two-inch stubble for legume/grass mixtures (the shorter height will help prevent the grasses from shading out the legumes).
The USDA Natural Resources Conservation Service (NRCS) has the following tips for livestock producers coping with drought:
- Use conservation practices that reduce runoff and encourage infiltration of water into the soil.
- Closely monitor soil moisture.
- Maintain and establish riparian buffers, filter strips, grassed waterways and other types of conservation buffers near ponds and streams.
- Prepare early for supplemental forage. During dry times, contract early for supplemental feed, or find alternative sources.
- Cull herds as necessary to maximize profits.
Remember to consider your water supply, as drought will increase your cattle's water needs, and provide salts and minerals. Cattle especially need the nutrients during times of drought.
Managing pastures for horses
As with livestock pastures, it's important to protect the plants during grazing. Colorado State extension specialists recommend taking animals off of the pasture when the grass is three to four inches high and allowing the grass to grow to six to eight inches. For small pastures, limit pasture access to a maximum of two hours a day for exercise. Expect to provide nutrition to the animals through supplemental feed; don't rely on grazing alone. Supplemental feeds will also help keep animals from trying to eat weeds that pop up during droughts; some of these weeds can be poisonous to horses.
Consider using a “sacrifice zone,” an area such as a dry lot where losing the grass won't be a major problem. A sacrifice zone is a good place to provide feed and house the animals when they cannot be on pastures that you are trying to rest.
If possible, you should have a plan of action in place before a drought hits. Your local NRCS office can help you develop a site-specific conservation management plan that will recommend conservation practices and management techniques to address erosion control, proper grazing and pasture maintenance.
You might ask your neighbors how they have coped as well.
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