Thursday, October 23, 2014
   
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Use care if using drought-damaged corn for forage

Drought, along with hail, wind, heat and other factors, has left some corn yields extremely low across the state. However, damaged corn often can be fed to livestock for forage.

Silage, green chop hay and grazing all can work to help capture the corn crop’s forage value for livestock, said Bruce Anderson, extension forage specialist in the Institute of Agriculture and Natural Resources at the University of Nebraska-Lincoln.

However, harvest costs can be high, especially when yield per acre is low, so it’s important to carefully evaluate the economics of any salvage operation, he said.

Anderson and UNL Extension educator Tom Dorn recommend taking these preliminary considerations into account:

If grain prices remain high, grain yield may not need to be very high to justify selecting grain harvest over forage harvest.

Sometimes leaving the corn residue can result in increased yield next year and that increase may provide more value than that resulting from forage use. See NebGuide G1846, Harvesting Crop Residues, available at www.ianrpubs.unl.edu/sendIt/g1846.pdf or from a local UNL Extension office, for information on evaluating your situation.

Check labels of all chemicals applied to be sure they are cleared for forage use and that the minimum harvest interval has been met.

Check with the U.S. Department of Agriculture’s Farm Service Agency and your crop insurer to maintain compliance with farm programs and crop insurance requirements.

Nitrate concentrations can reach toxic levels in weather-damaged corn. The harvest method can affect the nitrate, a particular concern when it’s being fed to livestock. Leaving a tall stubble (8 or more inches) will reduce nitrate risk but note eliminate it.

It’s important to analyze each harvest method accordingly—making silage, green chop, hay, grazing or windrow grazing, Dorn said.

When it comes to harvest methods, silage may be the safest method of harvest as fermentation usually (but not always) reduces nitrate levels and risk, Anderson said.

While green chop minimizes waste, it may also be the most dangerous way to salvage corn. If present, nitrates will start to change into nitrites (about 10 times as deadly) as green chop begins to heat.

Hay may be the most difficult method of mechanical harvest, especially if ears have started to form—the stalk and especially the ears will be slow and difficult to dry.

Challenges with grazing include acidosis risk for cattle not accustomed to grain if ears have started to fill (smart cows will selectively graze ears), waste from excessive trampling, availability of drinking water, perimeter fencing and nitrates.

NebGuide G1865, The Use and Pricing of Drought-Stressed Corn, available at www.ianrpubs.unl.edu/sendIt/g1865.pdf or from a local UNL Extension office, offers additional information.

Windrow grazing includes cutting as you would for hay and then grazing the windrows rather than baling them. It eliminates the cost of baling, transporting bales or feeding bales. It also eliminates any flexibility in feeding location and may reduce opportunities to sell the corn forage.

For more detailed information about harvest methods, consult CropWatch, UNL Extension’s crops production newsletter at cropwatch.unl.edu/.