– Sandy Smith, OSU Extension Educator, Carroll County (This article first appeared in the August 24, 2016 issue of Farm and Dairy)
When the rains return after experiencing drought conditions for most of the summer, that fresh green color that appears can have a tempting effect on farmers. Farmers can be tempted to open the gates and let their livestock graze wherever they want. Keeping managed grazing practices in place can help to get those dry pastures healthy again for this fall and next spring grazing.
Pasture damage: The amount of damage dry weather can cause on pastures depends on climate, soil type, forage species, fertility, and grazing management practices. A prolonged dry spell can limit a pasture’s forage output, and make pasture plants more sensitive to the effects of overgrazing and soil compaction. It can also cause an increase in weeds, some of which can be toxic to animals and compete with desired grasses.
Root systems: The plants’ root systems are very important in helping pastures survive the stress from drought and over-grazing, and are essential for soil stability and erosion control. A lack of moisture can suppress plant growth and root development. Without adequate roots, plants cannot pull moisture and nutrients from the soil.
One way to ensure that plant roots are able to do this is to allow animals on to pastures for short periods of time and rotate them so the pastures have longer rest periods between grazing. This can be accomplished by denying animals access to pasture when grass is less than 4 inches tall and not allowing them access to that area again until the grass grows back to 8-10 inches tall.
Weeds: Stay on top of weeds as they thrive in dry conditions. Weeds grow early in the season, before soil moisture becomes a factor. Weeds compete with desirable pasture plants for sunlight, nutrients and water. So if the weeds in your pastures are out of control, clip those areas to give your forage species a chance to reestablish themselves.
Fertilizer: Fertilizer applications during dry conditions are not recommended. You should perform a soil test and identify what nutrients the pasture is lacking and then apply fertilizers only when the soil moisture is adequate to maintain their availability in solution and increase nutrient uptake.
Management: Use caution, because under dry and drought type conditions, plants tend to accumulate nitrate, which can increase the chances of nitrate poisoning in livestock. Remember that dry weather does not impact everyone to the same extent and even multiple pastures within the same farm may not be affected the same way. Impact on pastures will depend on how they have been managed in the past.
Pasture management decisions after a drought situation cannot be separated from the usual pasture management plan that should be based on forage species, pasture conditions and stocking rate requirements. The right grazing management decisions should maximize your farms’ productivity and minimize any future problems.