Sunn hemp can boost summer pastures

Cows grazing sunn hemp at MU Greenley Research Farm in northeastern Missouri. Photo by Harley Naumann.

Frequent droughts in Missouri have livestock producers discussing more adaptable summer pasture options.

“With tall fescue as the dominant Missouri forage, there are few options to enhance those fescue fields to graze through a long, hot, dry spell,” said Tim Schnakenberg, University of Missouri Extension agronomy field specialist.

MU researchers have extensively evaluated sunn hemp as an option. Sunn hemp is a summer annual legume growing as tall as 6 feet, producing a large cluster of nutritious leaves from a single stem. Some summer annual forages will drop seed and come back the next year, but sunn hemp will not survive Missouri conditions even if it has a chance to produce seed, Schnakenberg said.

In a recent MU Extension study evaluating sunn hemp grazing by late-gestation cows, season-long sunn hemp accumulation reached 4,400 pounds per acre. Naumann and livestock specialist Chrisee Wheeler conducted the study at the MU Wurdack Extension and Education Center.