Corn Silage Drying Fast

Roland Kolb of Kolb's Dairy in East Coventy township, Chester County, chops corn for silage.

SENECA FALLS, N.Y. — When it comes to corn silage harvest, planning a strategy is vital to success for your growing operation.

Joe Lawrence, dairy forage systems specialist with Cornell College of Agriculture and Life Sciences Department of Animal Science, presented “Corn Silage Harvest Strategy: One Chance to Get it Right” during Empire Farm Days held Aug. 6-8.

Lawrence said that the first step is to “start with high quality forage.”

He explained that when producers begin with poor quality forage and manage it poorly, they end up with poor quality silage. Storing poor forage well or poorly managing high-quality forage also results in poor quality silage. For optimal silage, producers must begin with high-quality forage and manage it well.

“Small things getting overlooked (have) a big impact,” Lawrence said. “You can have several hundred tons of forage — several weeks’ or months’ worth of feed, depending upon your operation — that you won’t get based on a small decision made during your harvest. That decision can haunt you later.”

Moisture content, packing weight, kernel processing or length of cut, inoculants application and more can affect the quality and quantity of silage a dairyman needs for the next 12 or more months.

Lawrence said that considering “how do we store this feed in the best way for the best use” can help operators plan better.

He suggested that preparing a storage area to store crops for intended animal groups can help farmers use the right silage for the right animals.

Another question producers should ask themselves is, “When will these fields be ready?”

Lawrence said, “Some here who work with corn silage recognize the huge influence weather has.”

Late planting can reduce both quantity and quality. Lawrence said that weather can affect starch content because of rainfall at pollination and harvesting at proper whole plant dry matter (between 32% and 38%).

He said that some crops don’t put down deep roots during a wet spring, since the plants really don’t need to in order to obtain nutrients.

“It’s more susceptible to drought and wind,” Lawrence said.

He wants farmers to plan for the 2019 silage season by preparing “to manage two distinctly different forages.”

Sub-par immature silage should be stored separately from the top-quality mature silage intended for lactating animals. Producers who have these designated areas planned ahead of time won’t have to scramble at the last moment to find places to store different types of silage or, worse, combine the two and risk lowering their production. They also can avoid less-than-ideal storage that causes waste.

“The worst thing we can do is dilute our good corn silage,” he said.

He said that a bunk silo allows better ability to deal with leachate, but farmers should speak with a nutritionist about the length of cut. Kernel processing is likely not required.

Lawrence also wants farmers to learn when their crop really is dry enough to harvest.

“Most moisture is in the stalk and ear,” Lawrence said. “We get fooled by leaves and ears that look dry.”

A temperature of 28 F is a killing frost. And even as cold as 30 F, it takes several hours to kill the plant.

Many farmers look at the general rule of six to seven weeks from the appearance of tassels to harvesting for silage; however, Lawrence said that a late planting can push that harvest out later. The number of growing degree days is what really matters.

Cornell offers a free online calculator to figure growing degree days at It taps 30 years’ worth of data on temperatures specific to location to offer farmers a more accurate timeframe of when their fields should be ready to harvest for corn silage.

Lawrence listed several guidelines for successful harvest and storage management, including: safety every day, harvesting at correct maturity and moisture, retaining dry matter, providing proper location and construction of storage area, segregating feed by quality and intended use, managing storage and managing feeding.

Once harvested, silage needs proper storage to fulfill its purpose in feeding the herd.

“When we’re talking about storing feed, we’re talking about preservation of dry matter,” Lawrence said. “Shrink is a big loss of dry matter.”

Though not every aspect of loss is preventable, operators can mitigate some of it through better storage and management. He recommends 800 pounds of packing weight per ton or forage per hour. That moves silage at a manageable rate.

Keeping silage dry and airtight on a well-drained site can help preserve it. He noted as a negative example a farm he knew of that chose a silage storage site a few feet from a source of water. After a few months, half the feed was ruined because of the moisture.

Packing feed properly can save space — and maybe even the cost of a new bunk silo.

“Think about the lost capital of building a new bunk,” Lawrence said.

He compared an 800-cow dairy that changed only its storage density from 13 pounds of dry matter per cubic foot to 18 and reduced shrink from 24% to 15%. The farm increased its days of available storage from 290 to 449. Improved management saved the farm the cost of another bunk silo.

If farmers have to rent equipment to save the cost of a new bunk, “it can be worth it,” Lawrence said.