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Posted 6 October 2008. Crop Management.


Last Alfalfa Cutting Requires Careful Timing


Kansas State University. www.ag.ksu.edu


Manhattan, Kansas (October 2, 2008)--The arrival of autumn means that the year´s last cutting of alfalfa is near. Still, growers should keep a few things in mind.

 

"This cutting needs to be timed carefully. It can have a long-lasting impact on the productivity of the stand," said crops specialist Jim Shroyer with Kansas State University Research and Extension.

At this stage, the plants need to store enough carbohydrates to survive winter. Thus, a last cutting must allow their root reserves time to replenish adequately before fall´s first killing freeze (24- 26 degrees). Otherwise, the stand will be more susceptible winter damage and next spring´s early growth will be slower.

"The last cutting prior to fall dormancy should leave 8 to 12 inches of foliage or 4 to 6 weeks of growth time before the average killing- freeze date. That should allow adequate time," Shroyer said.

For northern areas of Kansas, particularly the northwest, the target date for that last cutting may already have passed. For southeast Kansas, the first week of October is the typical cutoff.

If the stand receives good rain in early fall and significant growth follows, producers may be tempted to make a last cutting in mid- October, he said. But, cutting then could reduce root reserves at a critical time.

"About the worst thing that could happen to an alfalfa stand cut in mid-October would be for the plants to re-grow about 3 to 6 inches and then get a killing frost. In that scenario, the roots´ carbohydrate reserves would be at a low point," the crops specialist said.

After a killing freeze, producers can safely hay any remaining forage, Shroyer said. They should act quickly, however, because the leaves will soon drop off.


Contact:
Elaine Edwards
elainee@ksu.edu