Mixtures of soybeans and oats, sorghum-sudangrass or pearl millet show good potential as emergency forages.
That's the conclusion reached after two years of field trials at the University of Wisconsin's Ag Research Station in Marshfield, where researchers examined several soybean-grass combinations.
“Conducting field trials on emergency forages was somewhat triggered by dairy producers' interest in having a few more available feed options when alfalfa winterkill is severe, as it was in 2003,” says Mike Bertram, assistant superintendent at the station. “Many producers also wanted an emergency forage crop that could easily be ensiled and work well in raising replacement heifers.”
According to Bertram, soybean-grass mixtures offer good yield potential and feed value for this type of use. “Plus, once a producer may finally determine by very late May or early June that alfalfa winterkill is widespread, the option to plant an emergency forage crop using a soybean-grass mixture remains a viable one.”
The trials involved conventional oats, forage oats, brown midrib (BMR) sorghum-sudangrass, and pearl millet. Each grass was grown mixed with conventional soybeans (Group I or II) or a forage soybean variety. As a control, each variety was also grown solo.
Yield and quality data from 2004 trials haven't been compiled yet. In 2003, despite dry weather, Bertram says soybean-grass mixtures performed fairly well.
Planting was done during the first two days of June that year. The soybean-oat mixtures were harvested in late July; the soybean-BMR sorghum-sudangrass and pearl millet mixtures, in mid- to late September.
One of the objectives was to find out if planting soybeans with grasses would bump up the protein content over that of grasses alone.
Despite the dry weather in 2003, the soybean-oat mixture reached 15-19% protein. The sorghum-sudan plus soybeans mix reached 8-9%, and the pearl millet mixture ranged from about 10% to 11%. However, there was no protein advantage for the soybean-grass mixtures over the solo grass plots, Bertram reports.
Overall, dry matter yields averaged slightly higher than 2 tons/acre. ADF averaged 35.6%; NDF, about 54%; and the relative forage quality score averaged 128.