2008 Iowa Corn Silage Yield Trial

Dale Thoreson, Dairy/Beef/Forages Field Specialist, Northeast

Problem Statement:

Corn silage is harvested from only 1.8% of Iowa’s corn acres. But most of the corn silage harvest occurs in the heavily concentrated dairy areas of the Northeast and Northwest portion of the state where corn silage use in diary ration is increasing. No current trials are conducted by the University to give silage users an unbiased evaluation of corn hybrids for silage.

Programmatic Response:

A research needs presentation at the 2008 NE IA Dairy Foundation’s annual meeting sparked interest in developing a corn silage trial at the foundation that would concentrate on hybrids used in the area. Through a coalition of ISUE Field Specialists (Dairy and Crops), seed corn dealers, NICC instructors, Dairy Foundation staff and volunteers a 12 hybrid trial was established on the Foundation’s land. Planting, thinning stands, estimating maturity dates and harvesting were conducted under the watch of ISUE field specialists. Plots were replicated and samples taken at harvest for analysis.


First, we were able to show volunteers, seed corn dealers, NICC instructors and Dairy Foundation staff the techniques needed and employed to conduct an unbiased research trial. Second, the results have been shared with the cooperators, through the Extension Dairy Newsletter, with media and at the NEIDF annual meeting. Third, additional seed corn dealers have asked to expand the trial with more hybrids. Dealers from as far away as West Central Minnesota have asked for the results. Fourth, by evaluating the results with the Michigan State University Corn Picker program, we were able to fine tune the results for the Dairy Foundation’s hybrid selection and arrive at a very accurate cost of corn silage, in front of the cow, for the Foundation. Fifth, the initial trial, which four seed corn companies paid for the analysis, has enabled the Dairy Foundation to achieve an $8,000 two year Leopold grant to further study the impact of a cover crop following corn silage harvest.


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Page last updated: April 6, 2009
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