By Jim Isleib, Crop Production Educator
Most farmers who feed corn silage already have a plan for 2017. A thoughtful review of your plans for corn silage could have a positive impact on your results. Hybrid selection is a big part of planning for a good corn silage year.
The days of selecting your corn silage field because it’s the poorer looking part of your total corn acres are pretty much gone. Much more attention is now given to the potential silage characteristics of corn hybrids. Corn hybrid trials for silage quality characteristics provide excellent selection tools. Michigan State University Extension bulletin E0431, “2016 Michigan Corn Hybrids Compared,” contains results of corn silage and grain trials throughout all five maturity zones within the state.
A combination of results from replicated and un-biased trials such as university testing programs, information from seed companies and results from on-farm strip trials, if available, should all be used when making seed selections. Characteristics of most importance include:
Longer-season hybrids generally result in higher silage yields. If a full-season harvest is expected, then a maturity 5-10 days longer than the relative maturity of hybrids selected for grain harvest is appropriate. However, if early harvest for silage or potential harvest for grain is a strong consideration, then a shorter season silage hybrid should be used.
Widening the harvest window by including silage hybrids with a range of relative maturity can provide farmers with more flexibility to chop the corn at its optimum moisture content. It will also improve the chances for better pollination if dry weather occurs during tasseling and pollen shed.
Yield and Quality
Silage yield is commonly reported in terms of dry matter per acre and as “wet” yield (65% moisture). This allows for fair comparison between hybrids harvested at different whole-plant moistures. Yield and quality go hand-in-hand when selecting corn hybrids for silage. Quality characteristics can be complicated. Most MSU dairy nutritionists agree that neutral detergent fiber is a key quality component of corn silage hybrids. This number is an indicator of the digestibility of fiber in silage produced from a hybrid, with lower neutral detergent fiber indicating higher fiber digestibility. Normal range of neutral detergent fiber has been estimated from 37.6–49.6, according to Dairy One.
If corn silage neutral detergent fiber on your farm is poor in a given year, the problem can be addressed by grouping cattle and feeding appropriately. High-producing cows benefit most from increased fiber digestibility, with increased dry matter intake and milk yield response. Lower digestible fiber corn silage can be fed to low-production cows, or dry cows far off from freshening. Feed testing and consulting with your dairy nutritionist or local MSU Extension dairy educator can help while planning.
Keep in mind that some traits relating to insect and disease resistance may be less important in corn intended for silage than in corn intended for grain. Herbicide and corn borer resistance will remain important. Corn rootworm resistance may not be as important since corn is often planted following alfalfa on Michigan dairy farms, with resulting lower pressure from corn rootworm during that year. This is due to the anticipated earlier harvest date.
Take a look at the 2017 version of the Handy Bt Trait Table compiled by MSU field crop entomologist Christina DiFonzo, Texas A&M University’s Pat Porter and Ohio State University’s Kelley Tilmon. Drought tolerance is also important on coarser textured soils, or where soil moisture may be depleted.
Taking the time now to review silage corn hybrid information from a variety of sources can help you fine-tune your hybrid selection for improved silage yield and quality, and reduced risk. Content for this article was adapted from “Corn Silage Hybrid Selection” by Jeff Coulter, University of Minnesota, and “Corn Hybrid Selection” from Corn Agronomy, University of Wisconsin Extension.
Part 2 of this article will focus on crop nutrient and harvest planning.