Harvesting and managing late-planted corn silage

Joe Zimbric
In the event of an early killing frost, the proper path forward in harvesting crops can be a major management challenge.

This year has been a very challenging year for forage production in Wisconsin and across the upper Midwest. A wetter than average spring lead to delayed planting in many areas of the state, and as a result we anticipate seeing high levels of variability in the quantity and quality of this year’s forage crops.

With several consecutive years of low commodity prices, many producers are ready to turn the page on 2019 after what is being called an ‘unprecedented’ growing season.

With over 20 million acres of ground put into the USDA’s prevented planting program this growing season, and with hay stocks at a 5-year low, there is an anticipated high demand for high quality forage throughout the 2020 growing season.

In particular, much emphasis should be placed on how producers should deal with this year’s upcoming corn silage harvest. Due to the delayed corn maturity in many areas across the state, producers are concerned about the possibility of an early killing frost.

Troy Brown’s, Form-a-Feed Forage Specialist, outlook on this issue was optimistic, and he predicts most growers will be okay for this season. However in the event of an early killing frost, the proper path forward can be a major management challenge.

If the plants are killed by a frost and are still immature in the field, they will likely contain too much moisture for immediate ensiling. Plants will dry slowly and dry matter losses will increase as the dead plants lose leaves in the field after a frost.

One strategy is to leave the crop in the field to dry down to an acceptable level unless dry matter losses become excessively high. An alternative approach is to chop higher on the plant. As a rule of thumb, chopping 12 inches higher than the normal 4 inch height will reduce the whole plant moisture by 3-4 points. Chopping 18 inches higher than normal will reduce whole plant moisture by about 5 points.

Of course, chopping higher will reduce total dry matter yields. Brown recommends a chop length of approximately 19 mm.

Forage samples can be evaluated at the UW Soil and Forage Lab, Dairyland Laboratories, or Rock River Laboratories.

We also anticipate that standing corn silage pricing is going to raise questions with many buyers and sellers this fall. Several tools are available to help folks make pricing determinations on the value of their forages, including the Corn Silage Pricing App that was developed by UW-Madison Extension staff and is freely available to download from the Google Play Store.

Joe Zimbric

Joe Zimbric is the Extension Crops and Soils Agent for Fond du Lac and Dodge County