Farmers have faced many challenges in producing high quality pasture and forage as the weather has alternated between drought and excessive rain. However, alfalfa winter injury was not one of them.

“After a winter with very little snow cover, I expected to see a significant amount of alfalfa injury, particularly since it broke dormancy relatively early in the spring,” explained Dr. Craig Sheaffer, University of Minnesota Extension forage specialist. However, the mild late winter and early spring temperatures just didn’t get cold enough to significantly damage alfalfa, even without much snow cover.

“In northern Minnesota, we had severe drought and little to no forage production in 2023,” said Troy Salzer, University of Minnesota Extension educator, “but surprisingly, the forages came out of dormancy this spring in better condition than I expected,”

Then in a complete 180-degree shift, excessive rainfall in alfalfa growing regions made the first-crop hay harvest extremely challenging. The drying windows were short and some hay was baled wet, which can result in heating, molding, dry matter loss and even spontaneous combustion.

One way to extend the drying window is to use a hay preservative. The upper moisture content threshold will depend on bale type and size but using a preservative adds a degree of harvest flexibility.

Utilizing a wet forage system also has advantages. Taking the forage as haylage or baleage cuts harvest time to one to two days instead of the three to four days needed for baling hay. Harvest conditions were better for second and later crops with wider drying windows.

Mid-August through early September is a good time to seed new stands of alfalfa, complete pasture renovations and take soil tests. It’s also a great time to assess alfalfa stands. A good stand of established alfalfa should have three to five healthy plants per square foot and 40 to 50 stems per square foot. New seedings should have 25 to 30 plants per square foot in the seeding year.

To reduce the risk of alfalfa winter injury in a good stand, avoid harvest from 45 days before the first average killing frost (26F) to the actual first frost, which usually corresponds to sometime in early September or October. Alfalfa can be harvested after a killing frost, but leave 6 inches of stubble to catch snow and insulate the crop.

If an alfalfa or mixed alfalfa stand is too thin going into winter, think about terminating it and reseeding in another area. Since the stand is going to be terminated, the forage can be harvested anytime during the fall.

If there are gaps in an alfalfa/grass stand, interseeding in mid-August is an option. However, to be successful, the stand needs to be open or suppressed. Otherwise, new seedlings will be unable to compete with the existing legumes and grasses. Make sure there is good seed-to-soil contact for germination.

For pasture renovation, another option is to suppress grasses in the spring and then seed with a no-till drill. Legumes, such as alfalfa, white clover or red clover, can also be introduced into the pasture at this time. Whether for pasture or hay, the keys to interseeding success include suppressing the stand and taking care of weeds and soil fertility needs.

Seeding cover crops as a supplemental pasture after soybean, small grain or silage harvest extends the grazing season. Mixes with annual grasses such as spring oats, winter rye or winter triticale, perennial fescues and brassicas are often used in these mixtures.

If acreage and fencing is available, pulling animals out of a pasture in August and allowing dry matter to accumulate in place for two to three months – called stockpiling – will provide additional grazing during the fall. Applying 50 lb N per acre in August will give grasses a boost in production. Meadow or tall fescue are best suited for stockpiling because they maintain forage quality after frost.

With the variable year-to-year weather, risks of forage shortages next summer can be reduced by planting some pasture to sorghum-sudangrass or sudangrass. These warm-season, annual grasses will provide 3-7 ton per acre of summer forage for grazing or haymaking.

For more information from University of Minnesota Extension, visit extension.umn.edu/crop-production.

Thanks to the Soybean Research and Promotion Council and the Corn Research and Promotion Council for their generous support of this program.