When alfalfa winterkills, it's much easier to replace its volume than its quality.
The handful of emergency forage crops recommended for the Upper Midwest includes two or three that can equal or beat alfalfa for yield. But none can match the quality of early harvested alfalfa put up without rain damage. If properly supplemented, though, some are good enough for lactating dairy cows.
For high-quality, early season forage, consider planting a mixture of field peas and either oats, barley or triticale. When chopped at the small grain's boot stage, the mixture supplies respectable yields early.
Adding peas to the small grain will increase silage protein content by several percentage points and reduce NDF by about the same amount.
“It's not alfalfa quality, but it's good enough for milk cows with additional supplementation,” says Paul Peterson, University of Minnesota extension forage agronomist.
Small grain-pea silage is also more palatable than grain-crop silage, but the yield is about the same.
Seed 45-60 lbs/acre of the small grain with up to 100 lbs/acre of field peas. If planted in light soils where alfalfa winterkilled, the crop can be followed by an August alfalfa seeding. If planted on different fields, alfalfa can be seeded with the mixture.
“Our data has consistently shown that, if oats are taken off for silage, we don't do much damage to the alfalfa underneath,” says Dan Undersander, University of Wisconsin extension forage specialist.
If you'll need forage even sooner, consider Siberian or Golden German foxtail millet, Peterson suggests.
“They don't have the quality of a small grain-pea mix, or the tonnage of some of the other emergency forages,” he says. “But they're good short-season crops that have always established well in our plots.”
Siberian foxtail millet reaches boot stage in about 45 days. Golden German is a bit later-maturing (55 days), and higher-yielding.
Several full-season annual crops can bring in ample quantities of forage for feeding next winter. Some of that acreage probably should be silage corn, says Peterson.
“From a tonnage perspective, combined with energy content and energy yield off an acre of land, corn silage is tough to beat,” he states.
Others that look good include forage sorghum and sorghum-sudangrass. Newer brown midrib hybrids are higher in quality than the conventional type, and yield almost as well (see story, pages 14-17).
Forage sorghum and sorghum-sudan perform best in warm weather, thus are best-suited to southern parts of the region. Even there, you might not get much forage if the growing season is cooler than normal.
“In a normal to cool year, corn silage is a better option,” says Undersander.
Forage sorghum provides one fall silage cutting, and sorghum-sudangrass can be managed as a multi- or single-cut crop. One fall cutting of either crop can produce as much yield as corn silage, but even brown midrib hybrids can't quite match its quality.
For higher-quality forage, plant brown midrib sorghum-sudan or sudangrass and cut it two or three times. Cut it when the plants get 3-4' tall, leaving an 8" stubble to improve quality and encourage regrowth, Peterson suggests.
“Apply 50 lbs of N after each cutting to encourage regrowth,” Undersander adds.
Of the two, sudangrass does better in cool weather and offers the highest forage quality. It's fine-stemmed, so can be made into hay or silage, while sorghum-sudan is for silage only.
Both also are well-suited for rotational grazing. But sorghum crops carry the risk of prussic acid poisoning. Peterson likes hybrid pearl millet as a possible alternative.
“In terms of productivity, it's fairly close to sorghum-sudan and sudangrass, but it doesn't have any prussic acid concerns,” he says.
Respectable yields of high-quality silage (18-20% protein) are possible with soybeans.
Undersander suggests planting a late-maturing grain-type variety to get a yield bump over earlier maturities. Harvest the crop after pods have formed, but before they've started to fill.
“If you wait too long, they have a higher oil content, and the silage isn't quite as palatable,” he says.
Wait To Reseed Winterkilled Alfalfa
Don't work winterkilled fields and reseed alfalfa this spring — unless the lost stand was seeded in 2002.
“We believe autotoxicity is real in any stand that's been in more than a year,” says Dan Undersander, University of Wisconsin extension forage specialist. “While you may get a stand if you reseed immediately, it'll yield significantly less than if you take it out for a year.”
If crop rotation isn't feasible, reseeding lost stands in August can work on lighter soils.
“That system can provide opportunities to incorporate manure and/or fertilizer, seed alfalfa when weed competition is generally not an issue, and get a jump on alfalfa production the following year,” says Peterson. “But it's probably too risky on more clayey soils.”