Productivity, botanical composition, and nutritive value of commercial pasture mixtures

Authors: Sanderson, Matt; Stout, Robert; Brink, Geoffrey

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/18/2015
Publication Date: 1/5/2016
Publication URL: http://handle.nal.usda.gov/10113/61833
Citation: Sanderson, M.A., Stout, R.C., Brink, G.E. 2016. Productivity, botanical composition, and nutritive value of commercial pasture mixtures. Agronomy Journal. 108(1):93-100.

Interpretive Summary: Managing for higher plant species diversity by planting mixtures of several grasses and legumes can improve pasture productivity. Our objective was to evaluate the productivity of a wide range of commercially available pasture mixtures to examine if the number of species in a mixture influenced yield and nutritive value. Yield of grazed forage mixtures increased as the number of species in the mixture increased. Specific mixtures within groups of similar species richness, however, varied greatly in yield depending on the botanical composition of the mixture. Kentucky bluegrass, birdsfoot trefoil, and timothy did not establish or persist well in mixture with the taller grasses orchardgrass, perennial ryegrass, or tall fescue. Our results suggest that a wide range of commercial mixtures can be productive and persistent in this environment and that planting forage mixtures with a combination of fast- and slow-establishing species can be effective strategy for mixture establishment.

Technical Abstract: Pastures in the northeastern USA often are planted to mixtures of grasses and legumes. There is limited public sector information on the performance of commercial forage mixtures. We evaluated a range of commercial pasture mixtures to determine if the number of species in a mixture affected yield and botanical composition. Three replicate plots of 25 mixtures, five each of 2, 3, 4, 5, and 6 species of grasses and legumes were planted in August 2007 near State College, PA. Plots were grazed by beef cows in 2008, 2009, and 2010. Dry matter 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. Dry matter yield was positively related to the number of species planted (r2 = 0.15, 0.18, and 0.26 for 2008, 2009, and 2010, respectively). Specific mixtures within groups of similar species richness, however, varied greatly in yield depending on the botanical composition of the mixture. Kentucky bluegrass (Poa pratensis L.), birdsfoot trefoil (Lotus corniculatus L.), and timothy (Phleum pratense L.) did not establish or persist well in mixture with the taller grasses orchardgrass, perennial ryegrass, or tall fescue. The short-lived species festulolium (X Festulolium Asch.&Graetn.) and red clover (Trifolium pratense L.) contributed significantly to dry matter production during the first year and were gradually replaced by longer-lived species such as orchardgrass (Dactylis glomerata L.) and red clover. Nutritive value of forage was not related to the number of species in the seed mixture but was related to the percentage of grass and legume. Our results suggest that a strategy of planting forage mixtures with a combination of fast- and slow-establishing species is effective for multispecies pastures.