Pasture and Forage Minute: Considerations for Grazing Corn Residue
Cornstalk Quality After Weathering
Fall rain and snow are good for wheat and next year’s crops, but it does have its drawbacks. One challenge is its impact on cornstalk feed quality.
While this fall has been relatively dry, there has and will continue to be areas that receive some rain or snow events. Rain reduces cornstalk quality several ways. Most easily noticed is how fast stalks can get soiled or trampled into the ground if the fields become muddy.
Less noticeable are nutritional changes. Rain or melting snow soaks into dry cornstalk residue and leaches out some of the soluble nutrients. Most serious is the loss of sugars and other energy-dense nutrients, which lowers the TDN or energy value of the stalks. These same nutrients also disappear if stalks begin to mold or rot in the field or especially in the bale. Then palatability and intake also decline.
Another factor that affects cornstalk grazing is wind. Throughout the fall, there always seems to be those days where excessively high winds will easily blow corn leaves and husks off the field. This, of course, can impact the amount of feed, and after grain, those leaves and husks contain the highest nutritional quality.
There is little you can do to prevent these losses. What you can do, though, is closely monitor cow and field conditions while adjusting your supplementation program accordingly. Since weathering by rain reduces TDN more than it reduces protein, consider the energy value of your supplements as well as its protein content.
Weathered cornstalks still are economical feeds. Just supplement them accordingly.
Cattle Compaction in Cropland
Are you looking for additional income from your corn acres or feed for cattle? Grazing corn residue is a low-cost winter feed source for cattle and a source of additional income for farmers without negative effects on the cropland.
Many crop producers are concerned that trampling from cattle grazing corn residue negatively affects crop yields. When grazed at proper stocking rates however, small but positive effects on crop production after grazing have been observed.
Research conducted at the University of Nebraska has shown that grazing corn residue at the recommended stocking rate does not reduce corn or soybean yields in irrigated fields the following growing season.
In fact, a long-term study in eastern Nebraska at the Eastern Research and Extension Center showed two- to three-bushel per acre improvements for soybean production following grazed corn residue in a corn-soybean rotation. This result was the same whether cattle grazed in the fall from November through January or spring from February through April.
A five-year study in western Nebraska measured corn yields from continuous corn after cattle grazing in the fall and found no negative effects on corn yields the following year.
It must be noted that minor surface compaction can result from grazing during wet weather. However, this compaction often disappears through the natural wetting and drying and freezing and thawing processes. Additionally, this compaction does not restrict root growth and does not carry over into the following growing season.
Grazing corn residue benefits both cattle and crop producers. Corn residue should be viewed as an economical source of winter roughage for cattle that can provide an extra source of income for corn producers that does not affect next year's crop production.