Corn farmers in areas under severe drought face a dilemma on what to do with their corn crop. In some instances, farmers who planned to harvest their corn for grain are now planning to harvest a portion or all of their corn as silage or baleage. A previous Crop News article provided guidelines for harvesting drought-stressed corn for silage. Since baleage is new to many farmers, this article provides additional guidance on how to best manage corn for baleage.
Nitrates accumulate in corn under drought, particularly in the lower portion of the stalk. This can be problematic because nitrate toxicity can occur in livestock if nitrate levels in feed are too high. Yet, ensiled corn represents only a portion of the total ration. Taking samples in the field for nitrates is not recommended because one-third to one-half of the nitrates will be transformed into gas during the ensiling process. However, the level of nitrate reduction during ensiling may be closer to the lower end of this range for baleage compared to corn silage.
Farmers can reduce risk of nitrate toxicity from ensiled corn by:
- Increasing the cutting height to 10 to 12 inches.
- Not feeding until the ensiling process has been completed (at least three to four weeks for baleage).
- Testing corn for nitrates after the ensiling process has completed but before feedout.
More information is available in Navigating nitrate toxicity in feedstuffs.
Harvest method and moisture
In general, a corn crop with a substantial number of plants containing ears is better suited to harvest as silage than baleage, although baleage also works if it is run through a total mixed ration (TMr) mixer prior to feeding. Otherwise cattle will preferentially sort through their feed.
Optimal harvest moisture for corn baleage is 40 to 55%, while harvest moisture greater than 55% is better suited for harvest as corn silage, depending on storage method.
Tips for harvesting
Discbines and disc mowers work best for cutting corn for baleage. Take tension off of the rollers, otherwise they will tear the ears off of plants if ears are present. Flail mowers are not advised because they can also break ears off of plants.
Lay the cut corn in a windrow in order to avoid the need for raking. Avoid raking cut corn because this causes the forage to become contaminated with soil. This increases the ash content of the forage, which can cause problems for the livestock it is fed to.
If available, use a baler that has a precutter on it to get tighter bales. This reduces the amount of oxygen in bales, which helps to lower the pH of the ensiled forage more quickly. This improves the quality of the baleage and reduces the length of time required before feedout. The precutter will also help with feedout and reduce the processing time in the TMr mixer.
Run the baler with as much tension as possible to get tight bales.
Use a baler that is set up to apply net wrap to bales, and also put an additional layer of net wrap on bales. This helps to pull the stalks together more tightly, resulting in less puncturing of plastic.
Bales harvested for baleage can be wrapped with solid plastic individually or in a line. According to a University of Wisconsin study, baleage should be wrapped with solid plastic as soon as possible after baling, and with at least 6 millimeters of plastic wrap (7 to 8 wraps). Be careful to avoid poking holes through the plastic, and seal any holes as soon as they are noticed.
Lactobacillus inoculant has not been recommended for baleage (Undersander, 2015). This is because Lactobacillus inoculant requires good coverage to be effective, and coverage is greatly reduced when harvesting corn as baleage compared to silage. Additionally, Undersander (2015) suggests that bales that are wrapped correctly do not require a forage preservative.
Estimating the selling price
One of the most common ways is to estimate the selling price of corn baleage is to first estimate the selling price of corn silage and then adjust it to baleage, as outlined below:
The price per ton of corn silage at 65% moisture content is typically calculated by assuming that it is 7.5, 8.0, or 8.5 times the price of corn grain (Lauer, 2020), although a factor of 7.0 is also commonly used.
The feed value of one ton of corn baleage is about 85% of that of one ton of corn silage, although sometimes a value as low as 75% is used.
Assuming $6.50 per bushel for grain, that the price per ton of silage (65% moisture content) is 8.0 times the price of corn grain, and that the feed value of corn baleage is 85% of that of corn silage, the selling price of baleage would be $44.20 per ton ($6.50 × 8.0 × 0.85 = $44.20). If the above scenario is kept the same but the feed value is changed to 75%, then the selling price of baleage drops to $39.00 per bale ($6.50 × 8.0 × 0.75 = $39.00).
Estimating the harvest cost
Typical costs for cutting and baling corn have been around $20 to $21 per bale, with an additional $7 to $9 per bale for net wrap and solid plastic wrapping, resulting in a total cost of around $27 to $30 per bale.
Another consideration is the amount of nutrients that are removed from the field with baleage (mainly P2O5 and K2O). According to guidelines from Iowa State University, one ton of corn silage at 35% dry matter content (65% moisture content) contains about 3.5 pounds of P2O5 and 9.0 pounds of K2O. If it is assumed that corn baleage has a feed value that is 85% of that of corn silage, and that it is harvested at 45% dry matter content (55% moisture content), then one ton of corn baleage would contain 3.83 pounds of P2O5 and 9.84 pounds of K2O. This was calculated as follows for P2O5: 3.83 = 3.5 × 0.85 × (0.45/0.35).
For corn acres without ears and reduced yields, nutrient removal may be somewhat different. According to the University of Wisconsin, the guideline values for nutrient removal for corn without ears and reduced yields are 4.6 pounds of P2O5 and 32 pounds of K2O per ton of dry matter.
The above values for nutrient removal can be multiplied by nutrient cost per pound to estimate the value of the nutrients that were removed from the field in corn baleage. This can be used to estimate the net economic return after harvest and nutrient removal.
Additional resources on crop production are available at Extension's Crop Production website.
For additional information on corn baleage, contact Troy Salzer (office: 218-749-7120, mobile: 218-591-0478, email: firstname.lastname@example.org).