Recent snow storms left at least some snow just about everywhere. This is good for alfalfa.
Alfalfa loves snow. In fact, nothing can increase the chance of alfalfa surviving winter better than a thick blanket of snow.
Good fall weather allowed alfalfa plants to harden well for winter, leaving them with a high concentration of nutrients and a low concentration of water in their roots. This winterized condition enables alfalfa crowns and roots to withstand temperatures as low as 5 degrees above zero.
This may not sound that cold. Air temperatures often get much colder than that. Fortunately, the soil doesn't get as cold as the air above it. And when soil is covered with a blanket of snow, this snow acts like a layer of insulation protecting the ground from bitter cold temperatures. In addition, it reduces the rate that soils and alfalfa roots dry out. This is why winters with little snow cover can cause more injury to alfalfa stands, especially if soils also are dry.
Fall management practices influence the effect of snow on alfalfa. Tall stubble provides some insulation value itself and it will catch more snow.
Also, avoiding alfalfa harvest during the so-called risk period from mid-September through mid-October helps alfalfa roots winterize well by building up nutrients and reducing water content.
Dave Varner is an Extension Educator with the University of Nebraska Cooperative Extension office in Dodge County. Dave may be contacted at 727-2775, 1206 West 23rd Street in Fremont, or at dvarner1@unl.edu
