Six adjoining 12.1-ha cool-season grass pastures at
the Iowa State University Rhodes Research Farm (Chariton,
IA; 42°00′ N, 93°25′ W) were used during the 2010
and 2011 grazing seasons. Pastures were not fertilized
or mowed during or at least 6 yr before the experiment.
A 141-m segment of a perennial flowing stream bisected
each pasture, which contained a mixture of smooth
bromegrass (Bromus inermis L.) and reed canarygrass
(Phalaris arundinacea L.) with lesser amounts of tall
fescue [Lolium arundinaceum (Schreb.) Darbysh.], Kentucky
bluegrass (Poa pratensis L.), and legumes.