Alfalfa and corn balance one another out in forage systems across the Midwest and Northeast. When both are included in diets, their complementary nutritional components can be incredibly beneficial to livestock. Growing corn and alfalfa in conjunction with each other also improves the economic and environmental sustainability of crop and livestock production.
Joe Lauer, agronomy specialist with the University of Wisconsin (UW) extension, notes in a recent Forage Focus article the numerous benefits from an alfalfa-corn crop rotation. “Growing alfalfa in rotation with corn reduces fertilizer nitrogen and pest control inputs, spreads labor activities, and reduces cropland vulnerability to soil erosion and nutrient runoff,” he explains.
A study, which began in 2010 at two UW agricultural research stations, is evaluating the effect that alfalfa-corn rotations have on grain and forage yields. The alfalfa was established in the spring of the year following corn production. Nitrogen fertilizer was applied to all corn, with the continuous corn system getting 30 pounds more per acre than the rotational systems.
Lauer explains grain yields for first-year corn after alfalfa were 15 to 19 percent greater than those of systems with continuous corn, and second-year corn yields were 12 to 13 percent higher. When compared to an adjacent corn-soybean rotation experiment, second-year corn yield improvement from the alfalfa-corn system was double that of the second-year corn in the corn-soybean system.
In separate plots, corn silage yield was evaluated. Silage yields were similar to each other in both years following alfalfa. Alfalfa yields were also similar for the first and second production years following seeding. Yields jumped by 3.4 to 3.8 tons per acre between the seeding year and the first production year.
Lauer notes that the study has only completed one rotation cycle. Future years will reveal if a corn grain (residue remains) or corn silage (residue removed) harvest has any impact on long-term yields.