By Kristen Ulmer et al.
For every bushel of corn, 18 lbs. of stems, 5.8 lbs. of cobs and 16 lbs. of husks and leaves are produced. Opportunities exist to remove the corn residue from the field for feeding later, or grazing residue in the field. There continues to be questions about the effect of residue removal on corn grain yields in subsequent years. Because yields are the most important profit indicator for a crop farmer, it is necessary to evaluate possible changes in grain yield with residue removed either by baling or grazing. With corn residue baling, it is important to determine the amount of nutrients removed per acre from the field to determine potential impacts on fertilizer needs for the next planting. The objectives of this 2- year study were to determine how grazing or baling of corn residue affects subsequent grain yield.
There was a difference among treatments (P < 0.01) in the amount of ground cover in the spring with grazed having 77.5% cover, baled having 45.8% cover and control having 88.7% cover. This demonstrates that grazing corn residue does not reduce soil cover as much as baling does and that a significant amount of cover remains after grazing. The baled treatments had numerically greater corn grain yields than control plots. This may be due to more available nitrogen and less ground cover enabling the ground to warm up earlier. Nitrogen is needed to degrade carbon, and with less residue being recycled, a short term bump in yields may be recorded.
Based on yield data, there is no evidence that baling, grazing, or leaving residue will change grain yield in the short term. Drewnoski et al. (2015 Nebraska Beef Report, pp. 53– 55) observed that in the long term, over a 10- year period, grazing corn residue at recommended rates did not impact the subsequent corn yields but improved soybean yields off field’s managed in a corn- soybean rotation.
Results indicate that, in the short term, removing corn residue through grazing or baling provides a potential feed resource with no negative impact on grain yield or harvest index. However, baling results in more loss of ground cover than does grazing. Baling also results in removal of N, P, K, and Ca. Nutrient removal by baling varied considerably among cooperators and among year within cooperators. These data demonstrate that it is important to weigh and sample bales to have an accurate estimate of the amount nutrients that need to be replaced after baling of corn residue. Leaving some residue in the field for soil health is recommended. Targeting a grazing strategy of removal of 8 pounds of husks and leaves per bushel means that just 12% of the total residue is removed by grazing.
Source: osu.edu