Sort & Cull

Using forage in the 2013 growing season will take extra management to ensure that the plants, and the animals eating those plants, are nourished properly after the severe drought that ravaged grassland regions last year.

How cattleman should handle the drought and its effects was the main topic of the 2013 University of Nebraska-Lincoln (UNL) Cow/Calf College, a meeting held Jan. 22 at the Roman L. Hruska U.S. Meat Animal Research Center (USMARC) near Clay Center, Neb.

Many regions' pastures and rangelands are seeing dry soils as well as disappointing forecasts with little moisture predicted. These dry field conditions have led to weak plants in pastures, according to Bruce Anderson, UNL Extension forage specialist.

In many cases, grass plants are very short and leaf area is nearly non-existent. This lack of leaf area will be a major issue going forward, anderson said.

"When leaf area is adequate, plants produce enough nutrients by harvesting sunlight via photosynthesis to supply what the plant needs for growth and have extra that is stored for reserve in the crown and roots," Anderson told DTN. "When leaf area is inadequate, growth is supported by whatever the leaves can supply, plus some of the reserves that were stored earlier."

Anderson said the current situation has reduced the amount of reserves for the plants and if these reserves are not replaced (mainly in the form of adequate leaf area), the plants are at risk of running out of reserves and not surviving. This situation, in turn, will reduce forage production, increase root death loss, reduce plant reproduction and change species composition in pastures.

Anderson added that plants' response to drought conditions is more severe if past or current grazing practices involved heavy stocking rates or continuous grazing. Grazing methods affect not only the plant growth but also root growth.

Looking forward to the 2013 forage growing season, even if pastures and rangeland receive "average" precipitation, the recovery from the drought will be slow. Plants will respond to normal rainfall with abnormal height, low root reserves, a slow increase in plant density and a change towards plants that reproduce rapidly, he said.

Anderson recommends farmers and cattleman manage grasslands coming off drought differently compared to normal moisture years.

Drought recovery management should include delaying the start of the spring grazing season so plants can increase leaf area and also using longer recovery periods between grazing, he said.

Other practices, such as resisting the temptation to restock the cattle herd back to pre-drought levels will be important, as well as using annual pastures to reduce pressure on existing grasslands. Annual pastures could be spring-seeded oats, summer-seeded sorghums, sudans, millets and fall-seeded oats and turnips, he said.

"The use of annual pastures/hay crops during drought can be an opportunity to take advantage of rain/soil moisture whenever you have it available," he said.

"Got spring moisture? Oats can use it well before it evaporates away. Dry early but get summer rain? Sorghums and millets use moisture and heat efficiently. Late summer opportunities? Oats again and turnips can work."

Anderson said in addition to seeing grasslands with thinner stands and slower growth rates, forage producers could also see areas of weeds that were not present in the past during the 2013 growing season. A weed is a plant not eaten by animals and containing anti-quality components, he said.

Weed issues on grasslands can be categorized into two groups. Limited problems would be grazed annuals including foxtail, crabgrass, sunflower, pigweed, etc.

Major weed problems would be ungrazed annuals (cheatgrass, sandbur, ragweed), noxious weeds (leafy spurge, thistles), poorly grazed perennials (western ragweed, ironweed, vervain), poisonous plants (Riddell groundsel, hemlocks, larkspurs) and brush and trees (cedar, locust, osage orange, buck brush).

The management strategy Anderson recommends for limited weed problems would be minor changes in grazing such as minimize grazing stress to desired plants and control seed production of the weeds only if necessary.

Major weed problems will call for different, more aggressive ways of control, he said. Methods would include burning, grazing, applying herbicide and mechanical elimination of the problem plants.

Anderson said while these tools will help to remove weeds, the best technique of grassland weed control is good grassland management, which includes maintaining healthy, vigorous, competitive grasses.

He also recommends producers be alert for weed encroachment following drought and determine the type of weeds that are growing. They need to be aggressive with these potentially permanent weed problems and also focus on better grazing management.

Russ Quinn can be reached at russ.quinn@telventdtn.com

(CZ\SK)

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