Alfalfa Management and Yield: What Is Achievable for Single- and Dual-Purpose Production?.

Alfalfa (Medicago sativa L.) is a productive, high-quality, perennial forage legume that provides several environmental and agronomic benefits in cropping systems. However, acreage has declined in the USA during the past half century, even though average yields are 50 to 70% higher than in 1960. Much of the decline has been attributed to harvesting at earlier developmental stages to maximize forage quality and to the increased use of corn silage as a ruminant feedstuff. But average yields tell a misleading story. Extension specialists and forage agronomists estimated that their ‘top tier’ farmers produced production-year yields of 13.4 Mg/ha dry hay (13% moisture) in the nonirrigated East and 17.9 Mg/ha in the irrigated West, 2 to 3 times the state averages. Data from the National Agricultural Statistics Service, alfalfa cultivar performance trials, and from whole-field research in Wisconsin confirm that these are attainable forage yields. By transitioning to dual-purpose production methods for alfalfa (leaves for feed, stems for biomass energy feedstock) and making feasible improvements in crop management, the top 10% of farms should produce 4.1 Mg stem DM/ha and 4.0 Mg leaf DM/ha in most of the nonirrigated East and 6.8 Mg stem DM/ha and 6.5 Mg leaf DM/ha in most of the irrigated West.