Revitalizing Winter Damaged Alfalfa Stands
This past winter was tough on local alfalfa stands. Usually in late-March and early-April I get a few questions about ‘thickening’ up alfalfa stands by interseeding alfalfa in an existing stand. This is an option only if the alfalfa stand is a new stand; that is, if the alfalfa was seeded last summer. Otherwise, in mature alfalfa stands (2 years old or older), interseeding alfalfa to thicken up the stand generally does not work. New alfalfa seedlings may emerge and look good early on, but they often die out over the summer due to competition, diseases, and autotoxicity present in the existing alfalfa stand. The OSU Forages Team (http://forages.osu.edu/) offers growers some excellent advice on renovating your winter-damaged alfalfa stand:
To extend the life of winter damaged alfalfa stands beyond this year, consider interseeding red clover or a grass such as ryegrass or orchardgrass. The yield benefit from perennial species may not be great until the second year, because they require some time to establish. Perennial ryegrass would likely provide an earlier yield boost because of its rapid establishment. Perennial ryegrass and red clover are slower to dry, so curing times will be lengthened compared with orchardgrass-alfalfa mixtures.
You can also consider interseeding your winter-damaged alfalfa stand with oat, beardless barley, annual ryegrass, or even wheat. These options (especially the wheat in our area) are quick to establish and will compete well in a thin alfalfa stand. The drawback is that you may have forgo hay and put up your stand has silage or balage. The following are excellent sources of information on annual forages and managing alfalfa where winter injury is an issue:
The Ohio Agronomy Guide, Chapter 7 (section on Annual Forages) http://ohioline.osu.edu/b472/0008.html
Articles on Univ. of Wisconsin Website: http://www.uwex.edu/ces/forage/news/current/winterkill2005.htm
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