The weather continues to challenge farmers in parts of Minnesota and elsewhere. With the late planting window closing, cover crop options for prevented plant acres should be considered. Crops selected for forage use would also be good choices as cover crops. There are several options depending on what a producer's needs and expectations are.
What are my options on prevented plant acres if I need forage?
Planting a cover crop for hay or grazingIf you are a livestock producer and are short on forage inventory, you may plant a cover crop for hay or grazing. However, your prevented planting payment may be significantly reduced if you harvest forage before November 1. Check with Farm Service Agency and your crop insurance agent for details. Then pencil out the economics for your own enterprise to decide whether or not this is a viable option for you.
There may also be restrictions on feeding a cover crop depending on which herbicides have been used in the past. For example, crops treated with glyphosate cannot be fed or harvested for 8 weeks, while herbicides containing acetochlor (Harness, Surpass, others) have an 18-month restriction for grazing or harvesting certain cover crops for feed. Be sure to read all labels from herbicides used this year as well as last season for harvest and feeding restrictions and crop rotation guidelines. For more information on herbicide concerns, see Is it legal to use a cover crop as a forage? Maybe not . . .
While alfalfa and corn silage are the preferred choices for forage quality and yield, summer annuals may help fill inventory gaps when these primary forages are in short supply and herbicide restrictions are not a concern.
Warm-season grasses include forage sorghum, sudangrass and sorghum-sudan. These warm-season grasses are more tolerant of drought and hot weather than cool-season small grains (oats, wheat, barley, triticale) and produce a large quantity of forage when managed carefully. Depending on your current nitrogen status, a fertilizer N application may boost forage production. While forage sorghum is generally ensiled, sorghum-sudans and sudangrasses can be grazed or harvested for hay. Grazing or green chopping young plants can result in prussic acid poisoning, so it is recommended to wait until the plants are at least 18 to 20 inches tall. When harvesting sorghum-sudan or sudangrass for hay, plants should be 3 feet tall to optimize quality and yield. In Wisconsin trials, a July 1 planting date allowed for 1 to 2 harvests and occasionally yielded as much as late-planted corn. Japanese and pearl millets, also warm-season grasses, are managed like sorghum-sudan hybrids and sudangrasses and have low prussic acid poisoning potential. If you plan to wait until November 1 to harvest, warm-season grasses will probably not be a good forage option for you. These grasses are not frost tolerant and will likely winterkill and lose significant forage value by November 1. For more information on warm-season grasses, visit the following sites:
- Sorghums, sudangrasses and sorghum-sudangrass hybrids for forage - University of Wisconsin
- Alternate forage crops (46 K PDF) - University of Wisconsin
- Forage options following alfalfa winterkill - University of Wisconsin
- Emergency forages - University of Wisconsin