Timing critical to forage harvest

LENEXA, Kan. – Milklines and black layers and silk dates and moisture content measurements – for every forage producer, it seems, there’s a different method of determining the perfect harvest date.

And while some methods by themselves may be more accurate than other methods by themselves, agronomists and dairy nutritionists have come to agree that a combination of in-field observation and more scientific measurements gives producers the most accurate indicator of optimal harvest date.

“Right after hybrid selection, harvest timing is one of the most important management decisions a forage producer makes,” said Joe Lauer, extension corn agronomist, University of Wisconsin.

Money to be made. “The most astute operators understand that a lot of money can be made, that you can turn around and profit from improved management through increased milk production.”

To that end, Lauer says, any and every tool available to the producer should be used to help pin down a date.

Though the consequences of inaccurate prediction may not prove disastrous, the better you do at timing the harvest, the more nutrients will be preserved in the cut forage.

Starts with planting. The most basic prediction of anticipated harvest date can be made as soon as the crop goes in the ground.

“You can get a general idea just by noting the planting date and the maturity of your hybrid,” said Lauer. “Then, you can use that information to inform your custom harvester of the potential harvest date.”

Once the crop is off and running, agronomic signals can help growers predict a more accurate maturity date.

Next indicator. “The next important indicator of how a field is maturing is the silking date,” Lauer said. “Generally, the period from silk to 50 percent kernel milkline is the same, regardless of the hybrid: about 42 to 47 days.”

Once the milkline starts to move, it’s time for more scientific measurements, such as a whole-plant moisture content analysis.

Though there are several methods for obtaining this measurement, Lauer and his colleagues agree that, whatever the method, it’s critical to have a stable endpoint weight before calculating dry matter content.

Drying a sample. The more accepted methods of drying a sample, particularly in a microwave or conventional oven, often lead to over-estimation of the dry matter content.

A more accurate measurement, he says, may be determined by a commercial testing service using near infrared analysis.

After the milkline is moving and a moisture content is established, it’s just a matter of calculating drydown rate and counting down the days until the crop reaches optimal moisture level.

An example. In Wisconsin, for example, producers use an average drydown rate of about a half percent per day. Growers in different climates may use that figure as a starting point, then adjust the rate based on local conditions-slower for more humid areas like the South and Southeast, faster for warm, dry regions.

“What you’re doing in the period right before harvest is fine-tuning the harvest date,” said Lauer. “Numerous management decisions need to be made to produce high-yield, high-quality silage.

“But if the crop can’t be cut at the right time, then stored at the proper moisture for adequate fermentation, all those decisions will have been for nothing.”

Quick cutting. After a harvest date is determined, growers should be concerned with just one thing: getting the crop cut and in storage as quickly as possible.

Here’s where the efficiency and capacity of your or your custom chopper’s harvesting equipment comes into play.

“Every day you lose, you lose weight and quality,” said Tim Meister, Division Marketing Manager, John Deere Ottumwa Works.

“That’s why you and your crew need to work efficiently; or, if you’re using a custom harvester, facilitate their operation in any way possible.

Plenty of people. “If you’re using a custom harvester, make sure you’ve got people on hand to help that crew however they can. Clear as many obstacles as you can from the fields to be harvested – old fence posts, irrigation pipe, anything that slows down the operation.

“It sounds simple, but we hear stories every year about harvester damage that could have been avoided.”

If you’re harvesting the crop yourself, Meister says, make sure your equipment is in top condition, and is able to handle the yields you expect in a timely, efficient manner.

“The work on a dairy farm never stops,” said Meister. “So producers or contract harvesters need to be able to get in and get out as quickly and efficiently as possible.”

Which, says Lauer, all goes back to accurate timing of the harvest.

“As the machines get larger and growers or their custom harvesters are covering more acres,” he said, “timing and scheduling of the harvest will become even more critical.”