Food plot species profile: Forage rape


Rape (Brassica napus) is a member of the Brassica family and "a new kid on
the block" in deer management in the U.S. Brassicas include cabbage,
cauliflower, canola, kale, rape, radish, turnip, rutabaga, and swede. They
have been used extensively in Europe, Australia, New Zealand and even Canada
for livestock grazing and, more recently, for deer farming. Due to my lack
of personal experience with the Brassicas, I have avoided discussing them in
Quality Whitetails. I now have some personal experience with them, found
some reliable university extension service data, and thoroughly read Ed
Spinazzola's book, "Wildlife Food Plots — Easy as 1-2-3."

Annual rape cultivars can provide deer managers with fast-growing,
high-yielding, quality fall forage. Rape can be very useful for extending
the grazing season into November-January when other forages are less
productive or dormant. Do not confuse forage rape with oil seed rape or
canola. Forage rape is a short-season, leafy Brassica whose stems and leaves
are ready to graze 30 to 90 days after establishment. It is important to
note here that most common rape varieties (and other Brassicas) should not
be planted more than two consecutive years on the same plot to prevent root
disease and pest problems. However, many of the improved varieties entering
the U.S. market from New Zealand have increased disease and pest resistance.


Rape is adapted to the entire U.S. and Canada, although it does not do
well in semi-tropical regions of south Florida. Cold, drought, and heat
tolerant, rape can provide valuable feed when other crops are less
productive. Rape requires good soil drainage and a pH between 5.3 and 6.8.
It grows best in soil with a pH above 6.0. Seed should be planted in a firm,
moist seedbed. Rape can be broadcast at four to nine pounds per acre or
drilled at two to six pounds per acre in 6- to 8-inch rows. It is important
not to plant the seed too deep, no deeper than 1/4 inch. Many managers are
successfully top-sowing the tiny seed (just like turnips) on bare soil just
before an expected rainfall. For the best production and highest-quality
forage, 70 to 90 pounds of nitrogen per acre is recommended, along with
about 50 to 60 pounds per acre of phosphorus and potassium. If planted
alone, fertilize with 300 pounds per acre or 19-19-19 or an equivalent, plus
100 pounds per acre ammonium nitrate. If mixed with legumes, you can skip
the ammonium nitrate. Properly fertilized, crude protein levels range from
18 to over 30 percent in rape leaves. Total digestible nutrients (TDN)
average about 70 percent, and dry matter tested about 15 percent. This
translates to a very high-quality, highly-digestible forage with a
high-moisture content.


Well-fertilized, well-managed stands of rape can produce one and
one-half to four tons of forage per acre over a relatively short grazing
season from October to January, moving north to south in the U.S. As for
management, it is very important to plant rape early — from June in the
North through September in the South. Later planted rape may not fully
mature before cold weather and may be subject to early overgrazing. Reports
on deer use of rape nationwide have varied from killed by overgrazing as
small seedlings (less than two weeks old) to hardly grazed at all and
everything in between (more research will help understand this variability).

Experts recommend not allowing grazing for 60 to 80 days for dwarf rape
varieties, which are probably better suited for deer management due to the
potential for overgrazing. Giant types have higher yields and are more
palatable but may be more subject to early overgrazing than dwarfs.

Deer commonly hit rape hard in November and December, removing all leafy
forage in a relatively short time. Livestock producers remove their
livestock at this time to allow 30 days or more of regrowth for a second
grazing period. Deer managers obviously cannot do this, so I recommend
strip-planting rape next to clover mixes, especially in fields one acre or
larger. Mixing rape with clovers, chicory, and/or wheat is another option
but careful attention to seeding rates is required. To prevent the rape from
shading out the other species, broadcast no more than one to two pounds per
acre rape, one to two pounds per acre chicory, five pounds per acre red
clover, and 30 pounds per acre wheat. The most common rape variety is dwarf
essex rape, though many improved varieties are available from Pennington
Seed Company, Barenburg Seed Company, and BioLogic.

Material from the Quality Deer Management Association.

Visit the web site at www.qdma.com