Improving corn silage yield, quality

MADISON, Wis. – When it comes to silage corn for dairy cows, selecting an appropriate hybrid and using good management practices can translate into a 17 percent to 33 percent increase in milk production per year for every acre of corn, according to a University of Wisconsin-Madison Extension corn specialist.

The yield and quality of silage corn can differ dramatically, according to Joseph Lauer. Silage quality and yield ultimately affect milk production on dairy farms.

“Selecting the appropriate hybrid is important for profits, but only half of the picture,” he said. “Using good management practices is as important as what you plant.”

Increased production. Lauer has evaluated nearly 2,000 different hybrids since 1995. The average silage yield from those hybrids translates into an estimated 24,000 pounds of milk per acre per year.

In a recent project at the college’s Arlington Research Station, Lauer examined the roles of hybrid selection and management practices, such as crop rotation, population density and row spacing.

He found that carefully selected, well-managed hybrids can mean the difference between producing 20,000-22,000 pounds of milk per acre per year vs. producing 26,000-28,000 pounds.

“This could make quite a difference to the farmer,” he said.

Pests, quality. Some modern corn hybrids that farmers use contain beneficial traits from other organisms that combat pests and improve quality.

One group of hybrids Lauer examined was Bt corn, which is grown on about a quarter of Wisconsin’s corn acreage.

Bt corn contains a gene from a soil bacterium that helps to defend the plant against the corn borer. Lauer found that the Bt corn hybrids were among the best hybrids he tested for yield and quality.

While Bt corn improved yield more than other hybrids in Lauer’s study, he stresses “farmers have to do their homework when selecting hybrids, and choose the one that works best for their situation.”

Selecting a hybrid depends in part on what type of cows will eat the corn. Beef cows can get by on lower quality corn, while high-producing dairy cows need a better quality corn, such as Bt or brown midrib (BMR) hybrids.

Management. Nevertheless, management practices are as important as selecting the right hybrid, Lauer said.

Farmers should rotate crops to replenish the soil with nutrients and break disease cycles.

And, when planting corn for silage, they should plant an extra 2,000 plants per acre, because slightly higher plant density produces higher yields without affecting silage quality.

Farmers should also evaluate planting data from past years, so that they can use their best fields for planting silage corn, Lauer said.

Better fields, which produce higher quality corn, will likely give farmers higher returns in the form of increased milk production than the returns they would earn raising corn for grain.