“Adding legumes to grass pasture is their primary use in the Ozarks area,” said Robert Kallenbach, professor and state extension specialist for the Division of Plant Sciences at the University of Missouri. “You can usually get calves to gain one quarter of a pound more a day when legumes are added to pastures.”
Cattle will gain from the use of these legumes because they provide a higher quality feed than the grasses harvested at the same time, Kallenbach said.
Preferred feed rations for cattle are 25-30 percent of pasture to be legume and approximately 70 percent to grass. Any higher of a legume ratio won’t do much more regarding nutrient value for the cattle.
“We have conducted studies that show that the diet is in this ratio as far as what cattle select to eat, the animal actually selects this legume/forage amount,” Kallenbach said.
Kallenbach said that legumes that will grow the best in the southern Missouri pastures are red and white clovers, annual lespedeza (or Korean), and alfalfa for hay use (which should be used more in the Ozarks area where soil nutrient levels allow). Other minor legumes include crimson clover and harry vetch.
Dirk Philipp, assistant professor for the Department of Animal Science at the University of Arkansas, said that there have been good experiences with crimson clover, arrowleaf clover and hairy vetch in the Arkansas area.
“What you should plant will depend on the purpose of course,” Philipp said. “They can all be established relatively easy, but it is difficult to make hay from hairy vetch for example, but this species may be more beneficial from a soil-fertility standpoint. Crimson clover and arrowleaf clover can be grazed in early spring until May.”
Because the digestibility of legumes is very high, legumes should be combined with other forages to optimize the required feed ration, Philipp added. “However, this is easier said than done. Early in the year, the annual legumes may be the only forage that is growing if the forage base is primarily Bermudagrass, however if the forage base is fescue, than legumes complement very well the fescue, since this grass has a lower digestibility.”
Kallenbach said the best management practices for legume establishment are based around the following factors.
1. Soil: Soil fertility needs to be ready, regardless of amount of broadcast seed. Legumes are pickier about soil fertility (they need a higher pH value), 6.0 pH value in soil. Pastures in the Ozarks area are typically below this, and may need to be limed (as based on a soil test recommendation).
2. Seed timing: Correct time of year is next. Clover and lespedeza seed can be spread in February and March. Clover and alfalfa planted in early September.
3. Competitors: As in taller grasses and forages. When adding legume seed to perennial grass pastures, there can be 200,000 seeds to 500,000 seeds per pound – so this little seed has to compete with established grasses. Plant your legumes in the pasture when grasses are short or freshly grazed in order to weaken grass competition. Use grazing management (flash grazing) after planting will also help to make sure legumes get established.
When planting these legumes, use a no-till drill, planting about 1/4 to 1/2 inches deep, Philipp said.
“Start grazing these legumes when clovers are 12-16 inches high and take them off at 4 inches,” Philipp recommends. “Stock quickly and on time in the spring. These plants grow rapidly during that time.”
Philipp also said that another key factor is planning ahead. “These legumes are not cheap to establish, so have a long-term grazing management plan on hand to see where and how these legumes might fit your operation.”
