Canola, turnips and other brassicas are forage options this fall
Unusual times call for unusual measures and this summer in Kansas and other Plains states have been unusual. Drought, record-high temperatures and other considerations may have agricultural producers considering different forage options and Kansas State University agronomists are encouraging producers to consider canola and other brassicas.
Brassicas, such as canola, turnips, kale, and rutabagas, can be productive, high-quality forage options for producers to consider this fall and winter, said Doug Shoup, southeast crops and soils specialist with K-State Research and Extension. Brassicas can be used on crop fields that would otherwise remain fallow and they also can be mixed with small grain cereals for a forage blend.
"In situations that make sense to use brassicas for forage, nitrogen rates of 50 pounds per acre will boost fall forage production," Shoup said. "Brassicas are high nitrate accumulators, so if excess nitrogen is in the soil, producers should not add more. It is important to use a soil test for this reason."
Producers also should test the forage for nitrates prior to grazing, Shoup said. Brassicas are high in quality and have high moisture content. When grazing brassicas, cattle will often become loose and require some roughage in their diet. Dry hay should always be available to cattle grazing on brassicas and should be about one-quarter of the ration.
If using canola, plant in late August or early September at a rate of 5 pounds per acre, said Mike Stamm, K-State Research and Extension canola breeder. If the stand is adequately established, grazing is typically available mid-October through December. Energy content and digestibility generally increase after a hard freeze, and cattle will quickly devour the forage.
"The top growth of canola in the fall is highly palatable for grazing," Stamm said. "Stocking rates have been as high as 1,000 pounds of animal per acre if ample forage is available. The quality is excellent. Protein levels are normally more than 20 percent. The relative feed value can be 400, compared to about 200 for rye/wheat forage. A typical average daily gain is about 2 pounds per head per day, but some ranchers have recorded over 3 pounds per day."
If producers wish to harvest canola for grain, they should expect lower yields with a graze-and-grain program. Canola crowns rest on top of the soil surface and when grazed, plants may be physically damaged by hoof traffic, he said. Reductions in grain yield of 25 to 50 percent are not uncommon. They should also remember that if canola seed is treated, the forage cannot be grazed. Canola that is grazed is currently uninsurable.
Like canola, turnips are a brassica crop that is high in protein and digestibility, said John Holman, K-State's Southwest Research-Extension Center cropping systems specialist. The advantage of turnips compared to canola is that once the top growth of turnips is killed by a freeze, the cattle will utilize the bulb until it is frozen.
Turnips should be seeded in late July or August at a rate of 3 pounds per acre, he said. The seed can be drilled or broadcast. Many producers have had turnip seed applied aerially into a standing corn crop, as long as little to no atrazine had been applied to the corn.
Turnip top growth can be grazed from late September until the first killing frost with temperatures below 18 degrees. Bulbs can be utilized into January as long as they remain intact. Turnip forage quality is very high, Holman said, ranging from 17 to 22 percent protein while the protein in the bulb will usually exceed 8 percent protein.
Cattle stocking rates for turnips are often high, ranging from 1,000 to 2,000 pounds of beef per acre, depending on available forage. Turnips can be blended with a small grain cereal crop. Cattle will initially seek out the cereal before utilizing the turnip tops until later in the season when the brassica forage becomes more desirable.