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Harvesting alfalfa this late in the season, either mechanically or with livestock, is typically safe from a plant’s perspective. We are past the point where alfalfa plants will have any significant regrowth, which would deplete the reserves already stored for overwintering. Removal of any lasting stubble can have some negative consequences on the crown though. The ability for snow to be trapped on the field, insulating the crown from temperature extremes, preventing desiccation, and providing some moisture in the spring should not be overlooked lightly.
If we do decide that use is worth the risk, we first need to decide how we plan on harvesting the stand. Harvest for hay this late in the season is extremely difficult. Cool days, lower temperatures, and increased risk of precipitation mean drying cut hay can be almost impossible. For this reason, if we want to mechanically harvest, feeding as green chop, ensiling, or wrapping as high moisture bales are probably better options.
Raising the cutter height a bit to improve airflow under the windrow can help things dry a bit faster, with the added benefit of some of the crown protection we talked about earlier. Moisture at this time of the year can cause compaction from equipment harvesting, while hoof action from grazing can damage crowns, especially in newly established fields. Having a sacrifice area to put animals on during inclement weather to avoid excessive damage to the stand maybe a good practice to consider. Additionally, wet weather could leave areas with high traffic rough for next year’s haying season.
A benefit of removing standing growth is a reduction in alfalfa weevil infestations by removing stems and plant parts that serve as a wintering site or a spring laying site for weevil eggs.
If grazing is our preferred method of harvest and we can safely say that our stand health is not a concern, the real question often being asked is “Can I be sure my cows won’t bloat if they graze my alfalfa?” To be quite honest, you can never be 100 percent certain that alfalfa won’t cause bloat.
Bloat risk is highest 3-5 days after a freeze and much lower a week after a hard freeze after plants have fully wilted. Even if grazing during this safer time, use good management methods to reduce the risk further. Have cows full before turning out to alfalfa and allow them to graze for an hour or two: initially or access to a small portion of the field. Wait until mid-day, after frost or dew is gene* before turning out, Gradually work up the grazing time or area to allow the rumen to adjust to the new, high-quality diet: while plants are still green. Other dry, palatable feeds or even bloat retardants can be provided to minimize risk even further.
Harvesting alfalfa late in the fall can be tricky but can be done. Just be careful and realistic.
— Ben Beckman is a beef systems Extension Educator serving northeast Nebraska. He is based out of the Cedar County Extension office in Hartington. You can reach him at: (402) 234-6821 or email: ben. [email protected] mailto:[email protected]
