Forage Options Following Floods

Flood Damage to Pastures May Require Use of Annual Forages

Russ Quinn
By  Russ Quinn , DTN Staff Reporter
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A pile of sand sits in a flooded field just east of the Elkhorn River near Scribner, Nebraska. Producers with flooded fields now face the daunting task of removing the large amount of sand deposited on their fields. (DTN photo by Russ Quinn)

OMAHA (DTN) -- Nebraska livestock producers who saw their pastures severely damaged from widespread flooding this spring might have to use annual forages until perennial forages can recover, according to University of Nebraska Extension specialists.

With pastures now buried under feet of sand along flooded rivers and fences completely destroyed, it will be a long-term project to restore these areas to productivity. Some pastures, however, might not recover enough to be whole again.


At a meeting in Fremont, Nebraska, on Tuesday afternoon, University of Nebraska-Lincoln (UNL) Extension specialists spoke on the subject of growing annual forages. The need for forages by livestock producers affected by flooding is both an immediate and longer-term need, according to Nathan Mueller, UNL Extension agronomist for Dodge and Washington counties.

Many farmers in the two counties have seen widespread flooding from three major rivers -- the Missouri, Elkhorn and Platte -- and from several smaller streams -- Bell Creek, Logan Creek and Maple Creek.

The questions Mueller has gotten most from livestock producers since the flood in mid-March is how to grow forage on flooded land and what other alternative options are available to them.

"Some have pastures with feet of sand deposited on it and no fences," Mueller said. "They are going to need forage, and hopefully this meeting will give them options."

Daren Redfearn, UNL Extension forage crop residue specialist, said many forage producers have contacted him, wanting to know what to do with sand on pastureland. It can be very costly to remove the sand mechanically, Redfearn said. But, at the same time, what plants could possibly grow with so much sand deposited on pastures?

"At some point, something will grow, most likely some annual like sunflowers," Redfearn said. "Do you remove the sand or plant on it? I don't think we really have a good answer yet on what to do."

Another issue will be how much sand is out there and how thick it really is. Some areas might have sand 4 to 5 feet thick, while other areas have a thinner layer. This inconsistent layer of sand will be a challenge to overcome, he said.

The good news is, grass will grow again, but it will take some time, Redfearn said. In the meantime, livestock producers need forages. Growing annual forages could be one way to ensure this need is met both in the short and long term, he said.


Redfearn said livestock producers in need of forages have a lot of choices when it comes to growing different annual forages. Certain seed might be more difficult to obtain, but generally, most of the seed is fairly available.

Annual forages can be divided into two categories: cool-season and warm-season species, Redfearn said. Cool-season forages include small grains such as oats, cereal rye, triticale, wheat or barley. Brassicas are also cool-season forages and include turnips, radishes and rapeseed.

Redfearn said the most common cool-season small grain is oats, which can be planted in the fall or early spring. Oats can be stockpiled, and the quality doesn't drop much, he said.

Brassicas can be planted in the fall or the spring, although production is higher when they are planted in the fall, he said. With it already being well into April, it is getting almost too late to plant oats or any cool-season annuals.

Warm-season forages include summer annuals such as sudangrass, sorghum/sudangrass, forage sorghum, pearl millet and German (foxtail) millet. Other examples of warm-season annuals are sunflowers, cowpea, Mungbean and Sunn hemp.

Considering it is almost too late to plant cool-season forages, planting warm-season forages might be the best option for producers who lost pastures due to flooding, Redfearn said. The planting window for warm-season forages is the end of May, and grazing or haying would be expected from late July through September.

"My take-home message is planting dates with annual forages is important," Redfearn said. "Delayed planting reduces fall growth potential, and the effects of late-fall planting carry over into the spring."

Before Aug. 1, summer annuals are the best choice, as cool-season annuals are risky, he said. From Aug. 1 to Sept. 1, cool-season annuals are the best choice.

Redfearn said, after Sept. 1, cool-season annuals are best and summer annuals are not recommended. After Oct. 1, cool-season annuals are the best bet.


Annual forages have different feed values for livestock, according to Kristen Ulmer, UNL Extension educator in beef systems. Dovetailing on what Redfearn said, Ulmer noted planting dates are extremely important. Research at the UNL Eastern Nebraska Research and Extension Center (ENREC) near Mead has shown this to be true, she said.

In one study, Ulmer said, oats were planted in a cornfield after corn silage was removed on Sept. 3, 2016, and then after high-moisture corn was harvested on Sept. 17, 2016. Ulmer said the oat biomass produced on the field planted on Sept. 3 was 2,510 pounds per acre, while the biomass on the field planted on Sept. 17 was only 574 pounds per acre.

"It can make a huge difference in production even as little as two weeks," Ulmer said.

The feeding value of annual forages can be maintained during the winter and meets calf and gestating cow requirements for protein and energy. Research has shown an oat-radish-turnip mixture planted on Sept. 8 will have a crude protein level of 23.2% in November and 22.9% in December.

Ulmer said calf performance on annual forages has also been studied at UNL.

In one study, calves grazed annuals for 40 to 60 days after the field was harvested for both corn silage and high-moisture corn. In the study, calves grazing after the corn silage had an average daily gain of 2.33 pounds, while calves grazing in forage after high-moisture corn was harvested gained 1.15 pounds.

Another consideration when grazing annual forages is metabolic disorders in livestock.

Ulmer said all annual grasses can have nitrate toxicity issues. Prussic acid can be seen in sorghum, sudan grass, sorghum/sudan mix and corn as a forage. She said issues with prussic acid can be avoided if grazing isn't allowed until the crop is 18 inches tall and waiting seven days after a killing frost.

Grass tetany can also be an issue with lush, immature grasses, she said. The main concern here is with lactating cows. But, in most cases, feeding a free-choice mineral with 12% to 15% magnesium (mg) with a target of 3 to 4 ounces per day per head should take care of the problem, she said.

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Russ Quinn