Skip to main content
ARS Home » Northeast Area » University Park, Pennsylvania » Pasture Systems & Watershed Management Research » Research » Publications at this Location » Publication #322268
Title: Evaluation of alfalfa-tall fescue mixtures across multiple environments

Author
item TRACY, BENJAMIN - Virginia Polytechnic Institution & State University
item ALBRECHT, KEN - University Of Wisconsin
item FLORES, JOAO - North Dakota State University
item HALL, MARVIN - Pennsylvania State University
item ISLAM, M ANOWARUL - University Of Wyoming
item JONES, GORDON - Virginia Polytechnic Institution & State University
item LAMP, WILLIAM - University Of Maryland
item MACADAM, JENNIFER - Utah State University
item Skinner, Robert
item TEUTSCH, CHRIS - Virginia Polytechnic Institution & State University

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/28/2016
Publication Date: 5/20/2016
Citation: Tracy, B., Albrecht, K., Flores, J., Hall, M., Islam, M., Jones, G., Lamp, W., Macadam, J., Skinner, R.H., Teutsch, C. 2016. Evaluation of alfalfa-tall fescue mixtures across multiple environments. Crop Science. 56:2026-2034. doi:10.2135/cropsci2015.09.0553.

Interpretive Summary: Planting legumes such as alfalfa in mixtures with cool-season grasses can have multiple economic and environmental benefits by helping producers cope with increasing fertilizer and herbicide costs and by avoiding excess application of N fertilizers that can have detrimental water quality and greenhouse gas impacts. This study compared alfalfa-tall fescue mixtures with alfalfa and fertilized grass monocultures to assess herbage yield, weed suppression and fertilizer N replacement values. The mixtures had greater yield and weed suppression compared with alfalfa monocultures and with tall fescue receiving low fertilizer application rates. The expanded use of alfalfa-tall fescue mixtures in forage production systems provides an important management option to increase yield, reduce weed pressure, and reduce the cost and negative environmental impacts of excessive fertilizer N application.

Technical Abstract: Binary grass-legume mixtures can benefit forage production systems in different ways helping growers cope both with increasing input costs (e.g., N fertilizer, herbicides) and potentially more variable weather. The main objective of this study was to evaluate alfalfa (Medicago sativa L.) and tall fescue (Schedonorus phoenix (Scop.) Holub mixtures across a wide range of environments to assess herbage yield, weed suppression and fertilizer nitrogen replacement values (FNRV). A common field experiment was established in 2009 and 2010 at six US study sites (Maryland (MD), Pennsylvania (PA), Utah (UT), Virginia (VA), Wisconsin (WS), and Wyoming (WY)). Experimental treatments included an alfalfa (ALF) monoculture, three alfalfa-fescue mixtures with seed ratios of 75:25, 50:50 and 25:75, and tall fescue (TF) monocultures that received nitrogen applications of 0, 50, 100, 150, 200 and 300 kg N/ha, respectively. Data were collected over a two year period. The responses of tall fescue monocultures to N fertilization differed among sites, and this contrasted with mixture yields, which did not exhibit site x treatment interactions (P > 0.05). Herbage yield and weed suppression were consistently higher in mixtures compared with ALF monocultures and TF monocultures receiving low N applications. In established swards, FNRVs for alfalfa were within the range reported for other studies (139-212 kg N ha**-1). The consistent yield performance across these multiple environments suggests binary mixtures of ALF-TF may be a good option for many forage-livestock producers although yields could be improved with location specific cultivar selection.