Big snowstorms have disrupted daily routines and created plenty of headaches for people around the country in recent weeks. For alfalfa growers, though, the snow has been good news, says Bruce Anderson, forage specialist with University of Nebraska Extension.
“Alfalfa loves snow,” says Anderson. “In fact, nothing can increase the chance of alfalfa surviving winter better than a thick blanket of snow.”
Moderate fall weather in many regions 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, he notes. This winterized condition enables alfalfa crowns and roots to withstand temperatures as low as 5 degrees above zero.
While that might not sound all that cold to producers in some regions, Anderson points out that 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. Plus, 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 can enhance the positive benefits provided by snow. “Tall stubble provides some insulation value itself, and it will catch more snow,” says Anderson. “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.”