Forage Quality Management of Kura Clover in Binary Mixtures with Kentucky Bluegrass, Orchardgrass, or Smooth Bromegrass

Kura clover (Trifolium ambiguum M. Bieb.) is a potentially useful perennial legume because of its excellent nutritive value and persistence under environmental extremes. However, information about forage quality of kura clover - grass mixtures adapted to the North-Central USA is limited. Objectives of this research were to determine forage nutritional value of kura clover-grass mixtures under different harvest frequency and cutting height regimes. 'Rhizo' kura clover was grown alone and in binary mixtures with 'Park' Kentucky bluegrass (Poa pratensis L.), 'Comet' orchardgrass (Dactylis glomerata L.), and 'Badger' smooth bromegrass (Bromus inermis Leyss.) at the Arlington Agricultural Research Station located near Madison, WI. Three harvest frequencies ($3{\times}$, $4{\times}$, or $5{\times}$ annually) and two cutting heights (4- or 10-cm) were imposed on each binary mixture and on kura clover grown alone. Higher nutritive value was observed in the binary mixtures with more frequent harvest and lower cutting height. Averaged over 3 years and all harvest frequency and cutting height treatments, the nutritive value of the Kentucky bluegrass and smooth bromegrass mixtures was superior to that of the orchardgrass mixture ($410\;g\;kg^{-1}$ NDF and $194\;g\;kg^{-1}$ CP in the Kentucky bluegrass mixture; $405\;g\;kg^{-1}$ NDF and $188\;g\;kg^{-1}$ CP in the smooth bromegrass mixture; $435\;g\;kg^{-1}$ NDF and $175\;g\;kg^{-1}$ CP in the orchardgrass mixture). All of the mixtures and harvest management systems evaluated in this study produced forage with quality equivalent to "grade one" alfalfa hay and suitable for highproducing livestock, even though the highest quality was observed in the Kentucky bluegrass mixture with $5{\times}$ harvesting at the shorter cutting height.