By JEFF BURBRINK
Extension Educator, Purdue Extension Elkhart County

Over time, an alfalfa stand will gradually go downhill. Since much of the stress that kills the plants occurs in the winter, April is a good time to assess the quality of your stand. The University of Wisconsin has a three-tier recommendation for assessing alfalfa stands. Fields with greater than 55 stems per square foot on average are in good shape and should be very productive.

If the stem count falls below 39 stems per square foot, you may want to consider replacing the stand. If the count falls between 40 and 55 stems per square foot, the stand has lost some potential, but is still productive. Stem count is not the only consideration, however. The crowns of the plant can produce stems even as their health deteriorates. Looking at the crowns predicts the future of the stand.

Digging a few crowns randomly around the field is recommended. When split open, a healthy crown will have an off-white color with little signs of decay inside. As the plant ages, crown rot can often be seen three to four inches below the surface, and the color of the health tissue will be a shade or to darker than a healthy crown.

When a crown is showing rot across 50 percent or more of its diameter, it is unlikely to survive the next growing season. If 30 percent of the crowns are showing this level of rot, the stand is one to consider replacing.

Weeds, of course, are another consideration. There is no standard to judge when weeds have become an economic problem in a field. Marginal stands can be improved if herbicides are used. Heavily infested fields are less likely to respond positively.

Along with your farm’s expected needs for forage, you can use these factors to determine if a stand is approaching the tipping point.