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Two Alternative Companion Crops For Legumes Show Promise In Early Tests

Farmers looking for both high yield and high quality forage during the year they establish legumes might consider annual ryegrass or festulolium as companion crops, according to a University of Wisconsin Madison study in central and northwestern Wisconsin.

“These new companion crops may enhance the overall quality of forage harvested in the seeding year compared with oat and oat-pea mixtures,” says Daniel Wiersma, a College of Agricultural and Life Sciences agronomist at the Marshfield Agricultural Research Station. “We found that ryegrass companion crops can increase the yield of first-year forage compared to legumes established without companion crops.”

Alfalfa, red clover and birdsfoot trefoil are the dominant forage legumes in the North Central states. Farmers often plant oat or oat/field-pea mixtures with the legumes to enhance forage yield, suppress weeds and control erosion during they year they establish a new legume crop.

“Earlier studies indicated that annual ryegrass and festulolium – a cross between meadow fescue and annual ryegrass – are highly digestible and produce yields comparable to oats,” says Wiersma. “But we weren”t sure how the legumes would fare when established with these two potential companion crops. Annual ryegrass can be aggressive and might reduce successful establishment of legumes.”

Wiersma, working with Marshfield Station dairy specialist Pat Hoffman and Mike Mlynarek, who directs the College”s research station in Ashland, planted the three legumes separately and with each of four companion crops in 1993 and 1994 at the Marshfield and Ashland stations. The companion crops were oat, oat-pea mixture, annual ryegrass and festulolium.

The researchers found legumes planted with companion crops always produced greater yields than legumes alone. At Ashland, the oat-pea companion crop produced the highest yield both years, averaging 0.6 tons of dry matter per acre more than solo-seeded legumes. At Marshfield, annual ryegrass and festulolium produced the greatest yields in 1993, when they averaged 0.65 tons of dry matter per acre more than oat or the oat-pea mixture, and 1.05 tons of dry matter per acre more than solo-seeded legumes. At Marshfield in 1994 there were no differences in yields among the companion crops in the trial.

Forage quality increased with the percentage of legumes in the forage, Wiersma says. Annual ryegrass and festulolium were usually the highest of the companion crops in crude protein and the lowest in both acid detergent and neutral detergent fiber.

“If conditions favor ryegrass, it does reduce legume yields the following year,” says Wiersma. In 1994, the legumes yielded an average of 0.3 tons of dry matter per acre less where annual ryegrass had been planted with them. In 1995, however, there were no differences in legume yields that could be traced to the companion crop planted the previous year.

Wiersma cautions farmers to start slowly with these companion crops. “In a whole-field trial at Marshfield, we found that ryegrass chops and blows hard,” he says. Also, keeping the seeding rate at 3 pound to 5 pounds per acre is important in preventing excessive competition from the ryegrass companion crop. The researchers are completing a trial at five Wisconsin locations in which the ryegrass companion crop was killed after the initial cut during the establishment year.

The research was supported by state funding to the UW-Madison College of Agricultural and Life Sciences and the UW-Extension Cooperative Extension Service, and a USDA Hatch grant from the College of Agricultural and Life Sciences.