Sheep and beef cattle producers looking for an option to provide additional forage and stretch or supplement existing stored hay inventory, should consider planting brassicas by early August.  Chris Penrose, Extension Educator in Morgan County recently wrote an excellent article on the use of brassicas (turnips, radishes, rape, kale) for grazing.  In the interest of space, I am going to excerpt a few comments from the article.  The entire article is available on the OSU Extension sheep team web page at: http://go.osu.edu/brassicagrazingoption.

“Brassicas can be seeded in July or August for fall/winter grazing. All members of the brassica family produce forage of exceptionally high (often 85-95%) digestibility. Weight gains by stocker cattle and feeder lambs have been 0.2-0.4 lb. /day for lambs and 1.5-2.0 lb. /day for stocker cattle.

Top growth generally will survive temperatures between 15-20 degrees Fahrenheit, while bulbs will be about 5 degrees hardier. If temperatures fall below this level, it is best to try to graze prior to temperatures going above freezing. The plants tend to become mushy and undesirable. Planting with oats or cereal rye will allow them to survive even cooler temperatures.

The common purple top garden type turnip, as well as other cultivars, can yield over 10,000 lb. /acre of dry matter. The tops average 12-20% crude protein while roots contain 8-12% protein.

Maximum quality of the plants occurs around 75 days (purple top turnips tend to mature earlier than other cultivars) and maximum quality is around 90 days as the roots mature (but the tops start to decline). At maturity, dry matter yields average around 40% in the tops and 60% in the roots.”

Brassicas can be planted using a drill or by broadcasting and then using a cultipacker to achieve good seed to soil contact.  While seeding rates can be as low as two pounds/acre, it is often difficult to adjust drills to a seeding rate that low.  Commonly, radish and turnips are seeded at two to four pounds/acre at a one-quarter inch seeding depth.  Apply 30 to 50 pounds of nitrogen/acre at seeding or shortly thereafter.

Rory Lewandowski is an OSU Extension Agriculture & Natural Resources Educator and may be reached at 330-264-8722.

CFAES provides research and related educational programs to clientele on a nondiscriminatory basis. For more information, visit cfaesdiversity.osu.edu.