Productivity, Botanical Composition, and Nutritive Value of Commercial Pasture Mixtures

Abstract

Pastures in the northeastern United States are often planted to mixtures of grasses and legumes. We evaluated several commercial seed mixtures to determine if the number of species in mixture affected yield and botanical composition in central Pennsylvania. Three replicate plots of 25 mixtures, five each of two, three, four, five, and six species of grasses and legumes were planted in August 2007 near State College, PA. Plots were grazed by beef cows for 3 yr. Dry matter (DM) yield was determined at each of the six harvests in each year. Botanical composition was measured at the first, third, and last harvest each year. Annual DM yield was positively related to the number of species planted (r2 = 0.15, 0.18, and 0.26 for 2008, 2009, and 2010, respectively). Mixtures within groups of similar species richness, however, varied in yield. Kentucky bluegrass (Poa pratensis L.), birdsfoot trefoil (Lotus corniculatus L.), and timothy (Phleum pratense L.) did not establish or persist well in mixture with taller grasses [e.g., orchardgrass (Dactylis glomerata L.)]. The short‐lived species festulolium (X Festulolium Asch. & Graebn.) and red clover (Trifolium pratense L.) contributed significantly to production during the first year and were replaced by longer‐lived species such as orchardgrass and white clover (T. repens L.). Forage nutritive value was related to the botanical composition but not the number of species in mixture. Results suggest that a strategy of planting mixtures with a combination of fast‐ and slow‐establishing species can be effective for multispecies pastures in central Pennsylvania.