Alfalfa Growth and Overwintering Status as of May 14

Submitted by:  Scott Reuss, Agriculture Agent.

The first set of data was collected for the alfalfa forage quality monitoring project on Thursday, May 14.  Alfalfa maturity is way behind normal, but this data collection allowed for a review of consistency of growth across the county, as well as a more formal survey of overwinter survival.  Current growth would indicate that first crop alfalfa harvest is not likely to start within the county until the very end of May at the earliest, and likely will not be needed in most areas until we are into June.

Reuss walked all the fields which will be monitored throughout the alfalfa first crop project.  Average height of alfalfa, across all fields, was only 6-7 inches, with the tallest field averaging about 8.5 inches.  No individual stems taller than 10 inches were noted.  This result is not overly surprising, due to the cool, dry conditions Marinette County fields have experienced in late April and early May.  It is anticipated that growth will accelerate dramatically prior to the next data collection, which will occur on Thursday, May 21 and will then take place Mondays and Thursdays until past harvest quality.  Data can be accessed here, or by calling 715-732-7510 or Reuss directly at 715-923-0807.

It is worth noting that forage grasses and some weed species have progressed more rapidly than forage legumes so far in 2020, as they can grow in cooler soil temperatures.  Many of the fields walked had grass height twice that of the alfalfa present.  This is an aspect which producers are going to need to consider as they plan harvest progression, as the grasses are going to likely be heading out prior to alfalfa maturity indicating harvest is needed.

The overwintering survey conducted as part of this set of field walks noted significant dichotomy between soil types.  Alfalfa on well drained soils overwintered exceptionally well, usually in the 98-99% survival range.  However, portions with elevated soil water levels did not fare as well.  In those fields, moisture-induced crown heaving and compaction-induced crown heaving significantly lowered survival.  Three fields had sizable areas with minimal survival and very uneven growth patterns.  A large percentage of plants had heaved crowns, even if they survived.  This likely means that further stand density erosion will occur over the year in those areas.

It is recommended that area producers try to find a couple hours to walk alfalfa fields which they know may be on more poorly drained soil types and see if they need to plan for additional work in those areas this spring.  In stands planted last year, you can re-seed alfalfa into them to hopefully establish fuller stands.  In older stands, choose clovers or perennial forage grasses, based on forage management plans and hopes for the field’s stand life.

If you want to discuss options for fixing these stands, contact Reuss at 715-732-7510 or e-mail to

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