Nutrient composition of selected emergent macrophytes in Northern Prairie wetlands

Abstract

North Dakota's seasonal wetlands, covering 1.3 million ha, are an important forage resource especially during dry years. A study was initiated in south central North Dakota to determine forage quality of dominant emergent macrophytes. Ten species, American sloughgrass (Beckmannia syzigachne (Steud.) Fern.), tall mannagrass (Glyceria grandis S. Wats. ex A. Gray), common reed (Phragmites australis (Cav.) Trin. ex. Steud.), whitetop or sprangletop (Scolochloa festucacea (Willd.) Link), prairie cordgrass (Spartina pectinata Link), slough sedge (Carex atherodes Spreng.), spikerush (Eleocharis macrostachya Britt.), baltic rush (Juncus balticus Willd.), hardstem bulrush (Scirpus acutus Muhl.), and three square (Scirpus pungens Vahl.) were collected twice a month, from mid-May until mid-August then after first frost. After drying at 60 degree C, samples were separated to leaf and stem where applicable. Analyses included in vitro dry matter digestibility (IVDMD), crude protein (CP), and phosphorus (P). Although species and season differences occurred, IVDMD, CP, and P declined linearly with season in each plant species and part. Depending upon the species mix, wetland hay harvested between bloom and mature stages would be expected to average 47-49% IVDMD, 7.6-14.0% CP, and .17-.29% P. Harvested early, mixed species wetland hays would provide adequate nutrients for dry pregnant cows. However, energy and P supplementation may be necessary for late harvested wetland hays.