There is a lot to consider when planting a cover crop for grazing. Timely planting, as well as selection of the right species, can impact yield and quality, according to University of Nebraska beef systems specialist Mary Drewnoski.

"When we talk about cover crops, what we are really talking about is trying to put forage production into a system with an already proven cash crop," Drewnoski told producers during the Nebraska Grazing Conference in Kearney. "It is a little different than a traditional annual forage system. What that means is we have a window of opportunity if we are looking at fall forage production. It is graded in our growing degree system," she says.

WHAT TO PLANT: Many producers ask what the best cover crop is to plant. Beef systems specialist Mary Drewnoski says the best place to start is by looking at the calendar.

"Planting date is extremely important when we are thinking about fall forage production," Drewnoski says. Referring to some previous research, she showed producers the difference in size of a purple-top turnip and a seed radish planted Aug. 25 vs. Sept. 8. While the earlier-planted radishes and turnips were of significant size, the later-planted ones had leaves, but barely any radish or turnip growth. "The heat units make a lot of difference," she says. "There was a quarter of a heat unit decrease during those two weeks."

A common question from producers is what to plant as a cover crop. Drewnoski recommends first looking at when they want to plant the crop. "If you can get it in before Aug. 10, warm-season grasses, like sorghum sudan or pearl millet, will provide the most yield," she says.

CONSIDER PLANTING DATE: Mary Drewnoski notes planting date is critical when growing cover crops for fall forage production.

However, if producers are worried about prussic acid or don't plan to graze until later in the season, cool-season grasses like oats or brassicas may be a better option. "Oats and brassicas will maintain a high quality, while still producing a significant yield," she says. "If you are planting after Aug. 10, you may want to consider a winter-sensitive, cool-season species like oats, or possibly spring triticale, or brassicas like rape, kale, turnips or collards," she said.

After Sept. 10, which Drewnoski considers to be the final date for fall forage production, producers should plant something they can utilize in the spring. "I would consider winter-hearty rye or triticale based on the potential date for grazing and the potential termination date," she says. "If you are looking for the earliest possible spring forage, rye or cereal rye is pretty hard to beat. But it will get rank if you graze later into the season. If you can't keep pressure on it, you will lose more quality with cereal rye than triticale," she notes. Cereal rye may also be the best choice if a producer plans to graze May 1, and winter triticale for grazing in June or later.

Planting as early as possible to maximize fall growth is important. "If you are trying to work this into a cropping system, you will probably be harvesting at the same time you need to be planting this cover crop," she says. Producers may want to consider hiring it done just because that extra two weeks of growth could pay for itself. "If you are thinking about forage production, you need to get it planted as early as possible," she says.

If producers have access to irrigation, she strongly encourages them to put a little water on to get the plants to germinate. "They are really not growing till they are germinated," she says. "The dryland situation is tougher, because you can't manage the moisture. You can't control rain.”

Clark writes from Potter.