Last minute emergency forage planting options
With time running out on the growing season, what are the best remaining options to extend forage supplies?
With the end of the growing season in sight and high-quality forage still in short supply, Michigan State University Extension phones are ringing with questions about what can still be planted in August. See “Emergency hay or silage forage crops” for an overview of the possibilities.
Unfortunately, Michigan has no annual forage options that will reliably produce harvestable yield in less than six weeks. In many parts of Michigan, an August planting pushes that six-week window into the possible frost zone. Moreover, as days get shorter and nights get cooler, plant growth slows down. A forage that might have been harvestable in six weeks with an early planting often takes considerably longer with a late summer planting.
Also, soil moisture is required for germination of annual forage seeds. With many parts of the state currently seeing dry conditions, do not expect to see fast establishment if small forage seeds are planted into dust. The seeds will wait for rain, and this can push the potential harvest date farther into the frost danger zone. Planting depth should be adjusted to the maximum recommended depth when planting into dry soil.
The planting window for significant yield potential on most warm season annuals is already closed in mid- to northern Michigan because these species are killed outright by frost. In southern Michigan, modest yields of sorghum, sorghum-sudangrass, sudangrass and millets may still be possible. Do not expect the same yield as in an ideal June planting. In East Lansing, Michigan, sudangrass and hybrids planted in early August after a wheat harvest yielded no more than 1 ton per acre of dry matter. That trial did not fertilize the forages, and yield might potentially have doubled had about 50 pounds of nitrogen been applied.
Be especially careful of prussic acid potential with low yielding forage sorghum because prussic acid is highest when forage is less than 24 inches tall. Sudangrass is a marginally better choice for late plantings than sorghum or hybrids. Teff may be the most realistic remaining warm-season option in southern Michigan for 2019 if a firm seedbed can be prepared and soil moisture is available. It will be difficult to get teff dry for hay in late fall, so grasslage or baleage will be the best harvest option.
The best option for harvested forage with an August planting is small grains. Use spring varieties for faster fall harvest potential but do not expect them to also survive winter. Winter small grains can be planted in August but are unlikely to produce harvestable forage mass in fall. Oats planted between July 15 and Aug. 15 are timed to reach boot stage (about six weeks after planting) right at first frost and can provide excellent forage. Research at the Dairy Forage Research Center in Wisconsin recorded yields of 2-3 tons per acre. Planting oats after Aug. 15 in Wisconsin produced much lower yields and is not recommended. Michigan is probably similar.
The Wisconsin research showed that grain varieties were a better option for late plantings because they mature more quickly than forage types. Field peas can be planted with oats to improve forage protein content. In East Lansing research, oats with field peas planted around Aug. 1 yielded up to 1.3 tons per acre. Oats have been one of the emergency planting options where seed is in short supply, but with the new harvest coming off, seed availability may improve.
In a year where all bets are off, consider leasing prevented planting acreage for grazing if possible. Fall grazing can reduce the amount of stored forage that is required to get livestock through to next season. Our best remaining option for fall forage yield potential is the brassica family, which can be grazed through December or even January using temporary electric fences. Unfortunately, brassicas produce forage so high in water content that machine harvest is not practical. Hay is out of the question, and it is nearly impossible to get silage into the 40-60% moisture range for good fermentation. Brassicas are best suited for grazing. Small grains (oats, rye or triticale) are often planted with brassicas to help provide fiber in the diet.
It is essential to get a brassica pasture crop planted as soon as possible because they have the same limitations as other annuals for slower growth under short days and dry soil. Brassicas hold quality after frost, but they do not accumulate much more yield. Radish and turnip are the best choices for fast growth and may reach grazeable yields in six weeks. Most others require 60 days or more. Aug. 20 is a practical cutoff for best forage yield potential in southern Michigan. The cutoff date is proportionately earlier as location shifts north. Later planting dates are possible, but yield potential will steadily decrease with later dates.
Pastures can still be used when forage mass is low, but livestock stocking density will need to be adjusted to fit the available forage. The good news is that grazing can economically utilize lower pasture yields than machine harvest. Remember that previous herbicide history will dictate what can be planted when grazing prevented planting acreage. For more information on grazing cover crops, see “Fall cover crop grazing basics.” MSU Extension will be releasing more details on utilizing annuals for fall grazing in the next few days.
For more information, contact Kim Cassida (forage and cover crop specialist, firstname.lastname@example.org), Phil Kaatz (forage educator, email@example.com) or Kable Thurlow (beef and grazing educator, firstname.lastname@example.org).