Alfalfa-grass mixtures can yield as well or better than alfalfa alone, an ongoing University of Minnesota study reveals.

The researchers are assessing forage yield, quality and species compatibility of alfalfa-grass mixtures vs. alfalfa monocultures on Minnesota farms. Plots of three alfalfa varieties with two varieties each of nine cool-season grasses were seeded on west-central and south-central Minnesota farms in August 2008 and on a central Minnesota farm in May 2009. The grasses are: meadow fescue, tall fescue, perennial ryegrass, smooth bromegrass, meadow bromegrass, reed canarygrass, timothy, festulolium and orchardgrass.

In 2009, the first production year, the mixtures were cut three and four times in west-central and south-central Minnesota, respectively. The highest-yielding mixtures in west-central Minnesota were alfalfa mixed with meadow bromegrass, reed canarygrass or perennial ryegrass, but they yielded slightly less dry matter per acre than alfalfa alone. On south-central farms, alfalfa-smooth bromegrass and alfalfa alone produced the highest yields.

Through three of four planned west-central cuttings this year, alfalfa-tall fescue outyielded the other mixtures and produced slightly more forage than alfalfa alone. Alfalfa-orchardgrass was the highest yielder through two of four planned south-central cuttings in 2010, beating the other mixtures and alfalfa only. That mixture also placed first after two cuttings in central Minnesota.

“To date, several mixtures are consistently yielding as much or more than alfalfa alone, with alfalfa-orchardgrass being the top yielder at two of three locations,” the researchers report.