PERENNIAL GRASSES: BIOMASS QUALITY AND YIELD COMPARISON OF DIFFERENT SPECIES IN THE NORTHERN GREAT PLAINS OF THE UNITED STATES

Traditionally, perennial grasses are planted as permanent forage for livestock production, offering additional ecosystem services such as reduced soil erosion, greenhouse gases mitigation, and wildlife habitat. With the new technologies perennial grasses can be transformed and used as biofuel crops. In this context, the objective of this work was to determine the yield potential and biomass quality of 12 different perennial grasses, under rain-fed conditions in Fargo, ND. The highest yielding species was tall wheatgrass (Thinopyrum ponticum) at 11.3 Mg.ha-1 dry matter, and the lowest yielding species was little bluestem (Schizachyrium scoparium) at 4.0 Mg.ha(-1) DM. Biomass quality varied among grasses and harvest date. Generally, ash content was higher in the second harvest. Lignin content was similar between cuts except in western wheatgrass (Pascopyrum smithii). Hemicellulose content was higher in the first harvest for both smooth bromegrass (Bromus inermis) and meadow bromegrass (Bromus biebersteinii). Cellulose content was generally higher in the second cut for most species, with the exception of sideoats gramma (Bouteloua cutipendula) and intermediate wheatgrass (Thinopyrum intermedium) which were higher in the first cut. Nitrogen uptake was similar among all grasses in both harvests, but lower in the second harvest. The gross calorific value (GCV) was higher in the second harvest only in reed canarygrass (Phalaris arundinaceae) and orchardgrass (Dactylis glomerata).