Drought Reduces Fall Pastures

This article is a modified version of the article that appeared in the November 2002 issue of the "West Virginia Farm Bureau News, WVU Update."

Ed Rayburn
Forage Agronomist
WVU Extension Service

Summer drought reduced fall pasture and may increase producers' need for hay. Late fall rains provide some late-season forage growth for those who applied nitrogen in August, but November is too late to apply nitrogen for fall forage growth.

The best way to benefit from the fall rains is to manage the grazing of pastures and aftermath on hay fields. Managed grazing will ensure livestock get the most out of the forage without harming the health of the plants.

Allow the plants to grow to a height adequate to ensure good root health before grazing. For bluegrass, this is 4 to 6 inches; for orchardgrass and endophyte-free tall fescue, 8 to 10 inches. Use rotational grazing to get good utilization and provide controlled rest for the plants between grazing. Do not allow the livestock to graze on more acreage than they can clean up in three to seven days. If managing for a grass-legume mixture, graze to a 2-inch stubble to help the legume.

Pastures that were overgrazed during the summer will benefit from resting until growth stops in November. It is tempting to let the cattle run the entire pasture when forage is short. However, this actually decreases plant health and forage production later. When cattle run all the pasture during a drought, they eat off most of the leaves, reducing the ability of the plant to catch sunlight. As a result, the plant's roots starve.

If the plants are allowed to rest through rotational grazing, the root system will stay healthy and the plants can build up energy reserves in the tiller base (grasses) and roots (legumes) for later growth. Under drought conditions when plants are rested and allowed to build up energy reserves, there will be compensatory growth by pasture plants when rainfall finally comes. Plants overgrazed during drought will grow slowly in comparison.

By resting drought-stressed pastures until mid to late November, energy reserves will increase since plants will catch sunlight and make sugars even when it is too cold for the plants to grow. Also during this time of year, grasses will develop new tiller buds necessary for next spring's forage production. With overgrazing in the fall, the pasture's growth potential next spring is jeopardized.

After the plant's energy reserves are restored and tiller buds formed, pastures can be grazed to use available top growth without hurting plant health or spring growth. Leave at least 2- to 4-inch stubble on orchardgrass it the end of grazing since new growth in the spring comes from the energy reserves in that part of the plant. Tall fescue and bluegrass, which have their energy reserves in below-ground stems, will survive closer fall grazing.

Resting the pastures in the fall may require holding the cattle in a relatively small area and feeding hay. Preferably, this area should be a section of pasture or hay land that will benefit from the manure produced.

More information is available in the following WVU Extension Service fact sheets available from your county Extension office or through the Internet: