Food Plot Species Profile - Kale
By: Kent Kammermeyer
In the last issue of Quality Whitetails, we dove into the Brassica family starting with forage rape. A close cousin to rape is kale, the focus of this column. The three main species of forage brassicas used for late fall pasture are rape, kale, and turnip.
Kale is a cold-hardy, crop-producing green high in nutritive value. It is not well adapted to hot weather. Best quality is produced where summers are cool or when it is grown into the fall or winter. Dry matter yields of kale range from 4,500 to 7,100 pounds per acre. Crude protein of kale leaves ranges from 18 to 25 percent, which is very similar to rape. Kale is slower growing than rape and takes a longer growing season to reach its full grazing potential (rape is faster at accumulating forage for browsing). However, it can provide excellent winter browse just like rape. Kale is of particular interest when a large amount of forage is desired for winter grazing. In this situation, managers need to allow for a long growing period (five to six months) in order to give kale time to slowly reach its potential yield.
Kale is adapted across the entire U.S. and up into Canada. It produces best in the northern states where summers are cool. However, it can be planted in late summer in Florida. Preferred time of planting in most of the U.S. is June or July. Plant at four to five pounds per acre and plan on leaf maturity for maximum yield to occur in 110 to 150 days in November, December, or January. Plant kale seeds one-half inch deep in well drained loams high in organic matter. Clay or sandy soils will do okay. The desirable pH is between 5.5 and 6.5. General fertilizer recommendations for kale are 60 to 100 pounds of nitrogen per acre, 80 to 120 pounds of phosphorus per acre, and 60 to 120 pounds of potassium per acre. In other words, 300 pounds per acre of 19-19-19 at planting would be a minimum application, with 400 pounds producing better growth. Other elements needed include one to four pounds of boron per acre, 60 to 120 pounds of magnesium per acre, and trace amounts of copper and zinc. Get a soil test to be sure of these requirements in your area.
Varieties of kale greens are of two types. Scotch types have gray-green and very curled and crumpled leaves while Siberian types are blue-green and less curled. Both dwarf and tall types are available with the dwarf types being preferred. Widely adapted varieties include Premier, Vates, and Siberian. In New Zealand, Kapeti kale has shown high yields, high-percent utilization, high-stem utilization, and improved club root resistance. Most preference tests reveal kale varieties sandwiched between the higher-preferred rape and the lower-preference turnip varieties. However, all are close relatives and it would not surprise me that other trials would show different results. Other varieties include Darkibor, Dwarf Siberian, Vates Blue Curled, Dwarf Curled Scotch, Blue Ridge, Dwarf Green Curled, Improved Vates, Redbor, Starbor, Tall Scotch, and Vates Dwarf Blue.
Just like rape, kale would be best suited for deer as a mixture with other brassicas, chicory, or clovers as long as the brassica rate is held low enough (less than two pounds per acre) to prevent shading of the clover and chicory companion plants. Better yet, divide your food plot in half, planting one strip in a rape/kale/turnip mix and the other half in a clover/small grain mix. This will assure survival of all varieties and species in the plot with both strips serving a specific function. The brassica function, of course, would be late fall and early winter grazing after the clover mix goes dormant.
There are numerous mixes on the market today including those sold by Barenburg, BioLogic, and Pennington. Best management of a kale stand would include application of additional N (nitrogen) at 30 to 60 days after establishment (100 to 150 pounds per acre of 34-0-0). Just like rape, do not plant kale or other brassicas on the same ground for more than two successive years to prevent potential fungal disease problems.