If you need emergency forage, you can't beat corn silage for yield and quality.

That's the conclusion reached by Paul Peterson, University of Minnesota extension forage agronomist, following a study that compared 18 crops for use as emergency forage.

“Even when we planted as late as early July, corn was consistently at the top,” says Peterson.

The study was conducted at three locations over two years in Wisconsin, at two locations over two years in Minnesota and at one location during one year in Michigan. The yield data have been compiled for all locations and years, but not all quality data are available yet.

“But I've gotten far enough into it that I think similar results will be borne out at all locations,” says Peterson.

The data have been completed for three trials planted on July 1, 2003, in Wisconsin. Corn silage topped each trial. At Arlington, silage hybrids finished first, second and third with milk/acre results of 28,900 lbs, 26,200 lbs and 23,200 lbs. Milk/acre combines yield and quality into a single term.

In most cases where the data have been compiled, longer-season hybrids performed better than shorter-season ones at both early and late planting dates.

“If you're faced with planting as late as early July, even early maturing hybrids often won't make it to maturity. So you might as well take advantage of the yield advantage of a longer-season hybrid,” he says.

Rounding out the top eight at Arlington were brown midrib (BMR) forage sorghum (22,400 lbs of milk/acre), soybeans (10,400 lbs), BMR sorghum-sudan (10,300 lbs) and hybrid pearl millet (9,600 lbs).

“BMR forage sorghum was often competitive with corn in terms of yield, but it was often lower in quality,” says Peterson. “In a couple of situations, the yield potential of BMR forage sorghum was incredible, but not consistent.”

In Otter Tail County, MN, BMR forage sorghum planted May 16, 2002, produced 16 tons of dry matter, or 45 tons of silage, per acre.

“It was hot and wet that year — almost tropical — and those are the growing conditions that BMR forage sorghum thrives under,” says Peterson.

Other findings: The warm-season, tall-growing annuals in the study, which included sudangrass, sorghum-sudan, BMR sorghum-sudan and pearl millet, all looked like good options if a multi-cut or multi-graze emergency forage is needed.

Among the four crops listed above, Peterson favors pearl millet because it can't cause prussic-acid poisoning.

“But pearl millet shouldn't be planted before June or if the weather is cool. It needs warm soil and weather.”

If you need a forage crop within two months and it doesn't have to be dairy quality, foxtail millet would be a good option, he says.

Small grain and pea mixtures did well in spring plantings, but weren't good options for later because they like cool weather.

Soybeans were most similar in quality to alfalfa. Crops planted July 1, 2003, at St. Paul, MN, received only one rain in July, August and September. But the soybeans still yielded 3 tons/acre of alfalfa-quality forage.

“However, there are some issues in regard to how to handle soybeans,” says Peterson. “Do you make soybean silage or hay? Wilting soybeans can be challenging, but conditioning may result in the loss of the high-energy green seeds.”